Chapter 40 NURSING MANAGEMENT: obesity

Written by Jennifer Kretzschmar, Paula Blackwell, Sharon L. Lewis

bariatric surgery

body mass index (BMI)

lipectomy

metabolic syndrome

waist circumference

waist-to-hip ratio (WHR)

Obesity

Obesity, like other nutritional problems, can occur in all age groups, cultures, ethnic groups and socioeconomic classes; intelligence and wealth do not preclude people from obesity. The nurse’s role is pivotal as caregiver, teacher and resource person in supporting those attempting to correct overnutrition and resulting altered states of health. Obesity is an abnormal increase in the proportion of fat cells. Weight gain during adulthood is characterised predominantly by adipocyte hypertrophy, a process by which adipocytes can increase their volume several thousandfold to accommodate large increases in lipid storage. This primarily occurs in the visceral (intraabdominal) and subcutaneous tissues of the body (see Fig 40-1).

Figure 40-1 Obese women. A, This woman has excessive fat deposits in her abdominal area, upper arms and breasts. B, This woman has excessive fat deposits in her upper arms, buttocks and thighs. The fat distribution in both of these women is common in obese people.

CLASSIFICATIONS OF BODY WEIGHT AND OBESITY

The majority of obese persons have primary obesity, which is excess kilojoule intake for the body’s metabolic demands. Others have secondary obesity, which can result from various congenital anomalies, chromosomal anomalies, metabolic problems or central nervous system (CNS) lesions and disorders. The first step in the treatment of obesity is to determine whether any physical conditions are present. A thorough history and physical examination are necessary and will reveal the extent and duration of the obesity.

The degree to which a patient is classified as underweight, healthy (normal) weight, overweight or obese is assessed by using a BMI chart. The calculated BMI is a common clinical index of obesity or altered body fat distribution. A well-accepted scale has been developed to calculate BMI using weight-to-height ratios (see Fig 40-2).¹ Individuals with a BMI between 18.5 and 24.9 kg/m² are considered to be of normal weight. Individuals with a BMI of 25–29.9 kg/m² are classified as being overweight, those with values of 30 kg/m² or more are classified as obese and those with a BMI of more than 40 kg/m² are classified as morbidly obese. In the past in New Zealand, the Heart Foundation’s BMI calculator was adjusted for ethnicity.² However, the New Zealand government has recently decided that it will adopt the WHO recommendations, which do not recommend ethnic-specific cut off points.³ For all New Zealand adults, obesity is now defined as a BMI >30.0 kg/m² and overweight as a BMI between 25.0 and 29.9 kg/m².³ This range is used in Australia for all members of the population.⁴

Figure 40-2 Body mass index (BMI) chart. Healthy weight: BMI 18–24.9 kg/m²; overweight: BMI 25–29.9 kg/m²; obesity: BMI ≥30 kg/m². BMI = weight (kg)/height ² (m²).

Table 40-1 shows the classification of overweight and obesity by BMI using the International Classification of Obesity and Overweight.⁵ Obesity is not the same as being overweight. Obesity carries many more risk factors and is a chronic condition with a strong familial element. For persons with a BMI of ≥30 kg/m², mortality rates from all causes, and especially from cardiovascular disease, are generally increased by 50–100% above that of persons with a BMI in the normal range.⁶^–¹⁰

TABLE 40-1 International Classification of overweight and obesity by BMI, waist circumference and associated disease risk ^*

* Disease risk for type 2 diabetes, hypertension and cardiovascular disease relative to a person of normal weight.

† Increased waist circumference can also be a marker for increased risk in persons of normal weight.

Source: Adapted from WHO global data base on body mass index, 2006. BMI Classification. Updated February 2011. Available at http://apps.who.int/bmi/index.jsp?introPage=intro_3.html; and National Heart, Lung, and Blood Institute Obesity Education Initiative. The practical guide: identification, evaluation, and treatment of overweight and obesity in adults. Washington, DC: US Department of Health and Human Services; 2000. Publication no. 00-4084.

As a consequence of problems with BMI in determining risk there has been a change in focus from BMI and skinfold thickness to abdominal fat mass and visceral adiposity, which are measured using magnetic resonance imaging (MRI), computed tomography (CT) scans, dual-energy X-ray absorptiometry (DEXA) and bioelectrical impedance analysis (BIA).^10,¹¹ Intraabdominal fat constitutes less than 20% of total body fat but is a major determinant of fasting and postprandial lipid availability due to its physiological (lipolytic rate and insulin resistance) and anatomical (portal drainage) properties. High levels of serum free fatty acids as a result of abdominal obesity cause excessive tissue lipid accumulation and contribute to dyslipidaemia, beta cell dysfunction, and hepatic and peripheral insulin resistance.¹²

Waist circumference is another way to assess and classify weight (see Table 40-1). People who have visceral fat are especially at an increased risk of cardiovascular disease and metabolic syndrome (see Chs 33 and 48). The waist-to-hip ratio (WHR) can also be used to assess the health risks associated with obesity. This ratio is a method of describing the distribution of both subcutaneous and visceral adipose tissue. The waist measurement is divided by the hip measurement to calculate the ratio. A WHR of <0.8 is optimal. A WHR of >0.8 indicates that an individual is at greater risk of health complications. The WHR is the preferred tool to measure for overweight and obesity when the patient is predominantly muscular; it is also a very simple way for people to assess their level of risk for diabetes.

Another way to classify obesity is by body shape or fat distribution. Individuals with fat located primarily in the abdominal area (apple-shaped) are at a greater risk of obesity-related complications as compared with those whose fat is primarily located in the upper legs (pear-shaped) (see Table 40-2). When a person has fat distributed over the abdomen and upper body (neck, arms and shoulders) they are classified as having android obesity. Gynoid obesity is a term used to classify persons who are pear-shaped. Genetics play an important role in determining body fat distribution patterns.

TABLE 40-2 Relationship between body shape and health risks

HDL, high-density lipoprotein.

Gynoid obesity carries a better prognosis but is more difficult to treat. It is believed that abdominal fat is more readily available and can be mobilised to maintain elevated triglyceride and lipid levels. Individuals with abdominal fat carry more visceral fat than pear-shaped individuals. Pear-shaped individuals carry more subcutaneous fat, which causes more cellulite to appear. Abdominal and visceral fat have been linked to metabolic syndrome, a major complication of obesity.¹² Visceral fat is more active, causing the body harm by decreasing insulin sensitivity and levels of high-density lipoprotein (HDL) cholesterol and increasing blood pressure. Visceral fat also releases more free fatty acids into the bloodstream.

OBESITY IN AUSTRALIA AND NEW ZEALAND

Overweight and obesity result from a complex interaction between genes and the environment. An imbalance between energy expenditure and energy intake from a long-term sedentary lifestyle and/or excessive energy intake causes an individual to become overweight or obese. Along with many other developed ¹ and developing countries both Australia and New Zealand are suffering an epidemic of overweight and obesity. In Australia, 68% of adult men and 55% of adult women are overweight or obese,¹³ up from 64% and 49% respectively 12 years ago. For children, there has been a significant increase in the proportion who are obese over the same 12-year period, from 5.2% to 7.8%. At the current rate of increase, it is predicted that 65% of young Australians will be overweight or obese by 2020.^6,¹⁴

The latest available figures indicate that the incidence of obesity and overweight in New Zealand is less than in Australia, but at 25% it is still almost double the OECD median.¹⁵ Additionally, in 2011 New Zealand women were shown to have the second highest body mass index (BMI) levels in the world after the US.⁷ The 2008 New Zealand health survey, ‘A portrait of health’, showed that obesity trends in New Zealand children are plateauing,¹⁶ but these findings have been questioned by other researchers, who believe the rate is still rising.¹⁰ Obesity has been shown to occur at higher rates in certain ethnic groups within New Zealand: Pacific Islander boys and girls are at least 2.5 times more likely to be obese than boys and girls in the rest of the population, and Māori boys and girls are approximately 1.5 times more likely to be obese. Similar ratios are evident in Indigenous Australian populations.^7,^15,¹⁶

There has been much discussion and research, particularly in New Zealand, into whether or not accepted norms for height and weight are appropriate for all populations and ethnic groups. In 2002 the World Health Organization (WHO) convened an Expert Panel to examine whether or not Asian and Pacific populations should have a different set of standards developed and it concluded that the current levels should be maintained as the International Classification for all populations.⁵ These levels are used in both Australia and New Zealand and allow comparisons across countries and ethnic groups.

The economic costs of obesity in Australia, which includes direct and indirect costs (such as wellbeing), are estimated to be in the order of $58.2 billion annually.⁸ The direct financial burden is around $8.25 billion ($3.6 billion in productivity costs; $2 billion in health system costs and $1.9 billion for carer costs). The net cost of lost wellbeing is estimated to be nearly $50 billion per annum.⁸ Within New Zealand, the direct cost of healthcare related to obesity is estimated at nearly $200 per person per year.¹⁵

Since the early part of the 21st century there has been a growing national focus on reducing the number of obese and overweight individuals in the populations of New Zealand and Australia and there are currently a number of programs that focus specifically on reducing the level of overweight and obesity and increasing the level of activity in the population—for example, the ‘Healthy eating-healthy action’ program in New Zealand ⁹ and the ‘Australia: the healthiest country by 2020’ strategy.⁴ Recent trends predict that, if the levels of obesity and overweight do not change, the life expectancy for Australian children alive today will fall 2 years by the time they are 20 years old.⁶ It is estimated that stabilising obesity at current levels will prevent the premature death of 500,000 Australians between now and 2050.¹⁷

AETIOLOGY AND PATHOPHYSIOLOGY

In one sense the aetiology of obesity can be considered simplistically. It occurs because energy intake exceeds energy output. However, the processes leading to obesity are much more complex and are still undergoing investigation. The cause of obesity involves significant genetic/biological susceptibility factors that are highly influenced by environmental and psychosocial factors. Once obesity is present, kilojoule consumption (energy intake) must exceed the energy expended for the condition to continue.

Genetic/biological basis

There is strong evidence of a genetic predisposition to obesity. Studies of twins, adoptees and families all suggest the existence of genetic factors in obesity. The heritability of obesity estimated from twin studies is high, with only slightly lower values in twins raised apart compared with those raised together. Estimates of obesity as an inherited problem are greater than 50%.^18,¹⁹ Similarly, in adoptees, the BMI of the children correlates with that of their biological parents rather than that of their adoptive parents.

The most common form of obesity is considered to be polygenic, arising from the interaction of multiple genetic and environmental factors. Identifying these genes will contribute to a better understanding of the pathogenesis of obesity. This could potentially lead to the development of strategies for the prevention and management of obesity.

Regulation of eating behaviour, energy metabolism and body fat metabolism is controlled by signals from the periphery that act on the hypothalamus (see Fig 40-3). Appetite is influenced by many factors that are integrated by the brain, most importantly within the hypothalamus. Input to the hypothalamus is received from the periphery from many different hormones and peptides (see Table 40-3). Obesity is associated with increased circulating plasma levels of leptin, insulin and ghrelin, and decreased levels of peptide YY. Interaction of these hormones and peptides at the level of the hypothalamus may be an important determinant in the factors contributing to obesity and are being investigated as possible obesity treatments.²⁰

Figure 40-3 Some of the common hormones and peptides that interact with the hypothalamus to control and influence eating patterns, metabolic activities and digestion. Obesity causes a disruption in this balance (see Table 40-1).

TABLE 40-3 Hormones and peptides in obesity

GI, gastrointestinal.

Adipocytes secrete a number of hormones and cytokines known as adipokines. Visceral fat accumulation results in alterations of these adipokines, thus contributing to causes and complications of obesity.²¹ Some of these adipokines include the following:

• Adiponectin, which regulates lipid and glucose levels. It is anti-inflammatory, antidiabetic and antiatherogenic. High levels prevent myocardial infarctions. Low levels are found in obese people.

• Resistin, which promotes insulin resistance and increases blood glucose levels. It is increased in obesity.

Environmental factors

Environmental factors play a role in obesity. Today’s society has greater access to food, particularly prepackaged and fast foods, as well as soft drinks, which are of poor nutritional quality. The portion size of meals has also increased markedly (see Table 40-7) and many fast-food franchises offer to ‘super-size’ meals, adding to the increase. Obese individuals tend to underestimate their food and kilojoule intake. Eating outside the home also restricts the ability to control the composition and quality of food.

TABLE 40-7 Portion sizes yesterday versus today

In addition, lack of physical exercise contributes to weight gain and obesity. With increases in technology and labour-saving devices, people are expending less energy in their everyday lives. The elimination of physical education programs in primary and secondary schools and increased time spent on video games and television-watching has contributed to the increase in sedentary habits. The Healthy Living Pyramid (see Fig 40-4) is a model of how to balance food groups and exercise.

Figure 40-4 The Healthy Living Pyramid.

Reproduced with permission of Australian Nutrition Foundation Inc. (Nutrition Australia).

Socioeconomic status can affect obesity in a variety of indirect ways. People with low incomes may buy food that is less expensive, of poorer nutritional quality and greater kilojoule content. For example, people with low incomes are more likely to purchase chips than fresh fish or fruit. Such people are more likely to live in environments that do not accommodate outdoor activities (e.g. tennis courts, swimming pools). The prevalence of obesity in New Zealand and Australia is highest in relatively deprived neighbourhoods.^6,¹⁵ Gyms tend to be attended by more affluent individuals. However, the pressures of long working hours may mean that people who are on high incomes will rely on prepackaged, processed foods and thus also be prone to obesity.

Psychosocial factors

The emotional component of the tendency to overeat is powerful. People use food for many reasons, including comfort and reward. Some people are triggered by specific foods to continue eating beyond satiety, especially when many flavours of food are available to select from, such as in smorgasbords or buffets. The social component of eating develops early in life when food is associated with pleasure and fun at such events as family or social celebrations and religious holidays. All of these factors must be included when considering the aetiology and treatment of obesity.

Health risks associated with obesity

In the 3rd century Hippocrates wrote ‘Corpulence is not only a disease itself, but the harbinger of others’, thus recognising, even then, that obesity has major adverse effects on health. Many problems occur in obese people at higher rates than in people of normal weight (see Fig 40-5). Mortality rises as obesity increases, especially when obesity is associated with visceral fat.²² In addition to these problems, obese patients have a reduced quality of life.²³ Fortunately, most of these conditions can improve if the individual loses weight.

Figure 40-5 Health risks associated with obesity.

CARDIOVASCULAR PROBLEMS

Obesity is a significant risk factor for predicting cardiovascular disease in both men and women. The WHR is the best predictor of these risks. Obesity, especially android obesity, is associated with increased low-density lipoprotein (LDL) cholesterol and triglyceride levels, and decreased HDL cholesterol levels. Obesity is also associated with hypertension. Hypertension can occur because of increased circulating blood volume, abnormal vasoconstriction, decreased vascular relaxation and increased cardiac output. Measurement of blood pressure requires the use of a larger cuff size to avoid increases caused by artefact (see Chs 32 and 33).

RESPIRATORY PROBLEMS

Severe obesity may be associated with sleep apnoea and obesity hypoventilation syndrome. Patients also have reduced chest wall compliance, increased work of breathing, decreased total lung capacity and functional residual capacity. Weight loss can bring substantial improvement in lung function.

DIABETES MELLITUS

Hyperinsulinaemia and insulin resistance are common features of obesity. Insulin resistance is most strongly related to visceral fat than to fat in other locations. Obesity is a major risk factor for type 2 diabetes mellitus. As many as 80% of patients with type 2 diabetes are obese. Weight loss and exercise are associated with improved glucose control in diabetes (see Ch 48).

MUSCULOSKELETAL PROBLEMS

Obesity is associated with an increased incidence of osteoarthritis, probably due to trauma to the weight-bearing joints. Hyperuricaemia and gout are well-recognised factors of both weight gain and metabolic syndrome (discussed later in the chapter).

GASTROINTESTINAL AND LIVER PROBLEMS

Gastro-oesophageal reflux disease (GORD) and gallstones are more prevalent in obese patients. Gallstones occur because of the supersaturation of the bile with cholesterol. Non-alcoholic steatohepatitis (NASH) is more common in obese patients. In NASH, lipid is deposited in the liver, resulting in a fatty liver. It is associated with elevated hepatic glucose production. NASH can eventually progress to cirrhosis and can be fatal. Weight loss and exercise can improve NASH (see Chs 41 and 43).

CANCER

Obesity is one of the most important known preventable causes of cancer. The underlying mechanisms are difficult to determine. The risk of breast, endometrial, ovarian and cervical cancer is increased in obese women. This may be due to the increased oestrogen levels (oestrogen is stored in fat cells) associated with obesity in postmenopausal women. Colon cancer has been linked to hyperinsulinaemia. Obese men have higher rates of mortality with cancer of the prostate (see Ch 15).

NURSING MANAGEMENT: THE OBESE PATIENT

Nursing assessment

Information that can assist the nurse in understanding the obese patient and provide a basis for intervention is presented in Table 40-4. By being sensitive when asking specific and leading questions, the nurse can often obtain information that the patient may withhold out of embarrassment or shyness. The nurse must provide acceptable reasons for such personally intrusive questions, respond to the patient’s concerns about diagnostic tests and interpret test outcomes. The patient’s answers to questions must be treated with respect, understanding and a non-judgemental attitude.

TABLE 40-4 Obese patient

NURSING ASSESSMENT

When assessing patients with obesity, the nurse should consider several different types of questions, such as the following:

The healthcare provider should explore genetic diseases (e.g. Prader-Willi syndrome, Bardet-Biedl syndrome, Alström’s syndrome and Cohen syndrome),¹² as well as endocrine factors such as hypothyroidism, hypothalamic tumours, Cushing’s syndrome, hypogonadism in men and polycystic ovary disease in women. Laboratory tests of liver function, fasting blood glucose level, triglyceride level, and LDL and HDL cholesterol levels assist in evaluating the cause and effects of obesity.

As part of the initial nursing history and physical examination, each body system should be examined, with particular attention being given to the organ system in which the patient has expressed a problem or concern. Measurements used with the obese person may include skinfold thickness, height, weight and BMI. Providing specific documentation on these areas assists the healthcare provider with a more in-depth history and physical examination.

More sophisticated measures of obesity use hydro-densitometry, dual photon absorption, MRI and ultrasonography and impedence apparatus. However, such measures are generally used only for research purposes.

Planning

The overall goals are that the obese patient will: (1) modify eating patterns; (2) participate in a regular physical activity program; (3) achieve weight loss to a specified level; (4) maintain weight loss at a specified level; and (5) minimise or prevent health problems related to obesity.

Nursing implementation

Health promotion

The nurse, working closely with the other members of the healthcare team, plays a major role in the planning and management of the obese patient. To be effective, the nurse must be aware of perceptions of and beliefs about obesity. Clear and consistent stigmatisation of obese people, and in some cases discrimination, can be documented in three important areas of living: employment, education and healthcare.²³ In addition to the negative social impact experienced by many obese individuals, many also suffer low self-esteem, withdraw from social interaction and experience major depression. In the workplace, obese women experience greater wage disparity from their normal weight counterparts than men. For obese men and women, fewer are hired into higher-level positions. Nurses need to be aware of current governmental public health strategies related to obesity^4,^9,¹⁴ and also the benefits of such programs. For example road safety, tobacco control and cardiovascular disease programs have made enormous contributions to improving both the quality and length of people’s lives.⁸ Nurses can advise patients who are obese about the programs that are available through national and local governments and encourage active participation (see Resources on p 1072).

Acute intervention

Although healthcare for obese people has inherently greater demands, healthcare providers regularly fail to address these needs and obese people routinely underutilise the healthcare opportunities available to them. Healthcare providers may often be reluctant to counsel patients about obesity because of the difficulties in raising the issue, time constraints during appointments and the fact that weight management is professionally unrewarding.

If a healthcare provider associates obesity with a lack of willpower and overindulgence, the patient can experience shame in a setting that claims to be a caring one. Nurses are in a pivotal position to help overweight and obese people deal with negative experiences and to educate other healthcare professionals to try to eliminate their bias against overweight patients. Before selecting a weight loss strategy with the patient, the following questions should be asked:

• What is the patient’s motivation for losing weight?

• Are there any major stresses that will make it difficult to focus on weight control?

• Does the patient have any psychiatric illnesses, such as severe depression, substance abuse or a binge eating disorder that will derail weight loss efforts?

• Can the patient devote the minimal amount of time (e.g. at least 15–30 minutes per day for the next 6 months) that is needed for a serious weight loss effort?

Motivation should be assessed as it is essential for a favourable outcome. Lack of motivation is a huge barrier to change. However, the reasons for wanting to lose weight should be focused on as the patient faces the challenges in dealing with obesity.

When no organic cause (e.g. hypothyroidism) can be found for obesity, it should be considered a chronic, complex illness. Management of chronic disease is discussed in Chapter 69. Any supervised plan of care should be directed at: (1) successful weight loss, requiring a short-term energy deficit; and (2) successful weight control, requiring long-term behaviour changes. These are two different processes. A multi-pronged approach should be used with attention to multiple factors, including dietary intake, physical activity, behavioural modification and perhaps drug therapy. By focusing on more than one aspect, a better balance may be given to weight loss and weight control efforts. All opportunities for patient education should stress healthy eating habits and adequate physical activity as lifestyle patterns to develop and maintain (see Box 40-1).

Even with a comprehensive action plan, there is a high rate of weight regain among people in all age groups. Considering the amount of time and effort expended in the process of attempting to lose weight, this is discouraging. For successful management of obesity, it helps if obesity is viewed as a chronic condition that necessitates day-to-day attention to lose weight and maintain weight loss. It is essential that the nurse has a non-judgemental approach in helping patients manage their problems related to obesity.

Multidisciplinary care

NUTRITIONAL THERAPY

Restricted food intake is the cornerstone for any weight loss or maintenance program. A good weight loss plan should contain foods from the basic food groups (see Fig 40-4 and Table 39-1). Diets may be classified as low kilojoule (3300–5000 kJ per day) or very low kilojoule (<3000 kJ per day) (see Table 40-5).

TABLE 40-5 5000 Kilojoule-restricted weight-reduction diet ^*

NUTRITIONAL THERAPY

* For 4000 kilojoules, omit 1 fruit exchange and change low-fat milk to skim milk. For 6000 kilojoules, add 1 meat, 1 fruit and 2 fat exchanges; change low-fat milk to whole milk. For 7500 kilojoules, add 2 bread, 3 meat, 3 fat and 1 fruit exchanges; change low-fat milk to whole milk.

† One extra fat exchange allowed for each cup of 2% low-fat milk; 2 extra fat exchanges allowed for each cup of skim milk.

Patients on low and very low kilojoule diets need frequent professional monitoring because the severe energy restriction places them at risk of multiple nutrient deficiencies. A diet that includes adequate amounts of fruits and vegetables provides enough bulk to prevent constipation and meets daily vitamin A and vitamin C requirements. Lean meat, fish and eggs provide sufficient protein, as well as the B-complex vitamins. The only effective method of treating primary obesity is to restrict dietary intake so that it is below energy requirements. It is rare to find an overweight person who has not at some time attempted to lose weight. Some people have met with limited and temporary success, and others have met only with failure. It is likely that the majority of these people attempted weight loss by trying out at least one of the many fad diets that offer the enticement to eat and get slim. Weight reduction diets found in the popular media that advocate the elimination of any one category of foods should be discouraged.²⁴ While elimination of all carbohydrates can lead to weight reduction, it is only because total kilojoules are reduced. The elimination of carbohydrates reduces the opportunity to get enough dietary fibre, vitamins and minerals.

In general, fad diets claim weight loss quickly, easily and inexpensively.²⁴ Although it is true that initially weight is lost, it is not fat but body water that is lost. The normal fat cell is composed of approximately 80% fat, 18% water and 2% protein. It is also a storage area for small amounts of glycogen. Glycogen is known to bind with water. When reducing diets severely restrict carbohydrates, the body’s glycogen stores become depleted within a few days. It is only when the glycogen pool is almost depleted that protein and adipose tissues are burned to release energy for bodily functions. An obese patient must understand that following a well-balanced, low-kilojoule diet is an essential part of weight loss and is more likely to be successful in the longer term.

The degree of success of any reducing diet depends, in part, on the amount of weight to be lost. A moderately obese person will obviously attain the goal more easily than a morbidly obese person. Perhaps because men have a higher percentage of lean body mass, men are able to lose weight more quickly than women. Women have a higher percentage of body fat, which is metabolically less active than muscle tissue. Postmenopausal women are particularly prone to weight gain, including increased abdominal fat.

Current popular diets include those that are either low in fat or low in carbohydrates (see Table 40-6). They have been shown to have good effects on blood lipid concentrations, blood pressure and glucose control. However, these effects are generally short-lived and not superior to standard approaches over the longer term. The degree of weight loss strongly depends on the ability of patients to adhere to their diets. The more restrictive the regimen, the greater the demand for intense discipline in the face of an intense desire to eat foods not allowed on the diet.²⁴

TABLE 40-6 Comparison of popular diets

* Glycaemic index is the term used to describe the rise in blood glucose levels after a person has consumed a carbohydrate-containing food.

Motivation is an essential ingredient for the successful achievement of weight loss. The obese patient must see the need for weight loss and weight control and the advantages that will occur. The nurse can assist by helping the patient track eating patterns by keeping a diet diary. A frank discussion of eating habits may help the patient realise that eating often is the result of bad habits developed over time and not of hunger. The bad habits must be changed, or weight loss will only be temporary.

Setting a realistic and healthy goal, such as losing 0.5–1 kg per week, must be mutually agreed on at the outset. Trying to lose too much too fast usually results in a sense of frustration and failure for the patient. The nurse can help the patient understand that losing large amounts of weight in a short period causes skin and underlying tissue to lose elasticity and tone, which causes unsightly folds of flabby tissue. Slower weight loss offers better cosmetic results.^5,⁸ Inevitably, patients will reach plateau periods during which no weight is lost. These plateaus may last from several days to several weeks. It is especially important for patients to realise that these are normal occurrences during weight reduction, so that discouragement, frustration and giving up of the prescribed dietary plan are prevented. A weekly check of body weight is a good method of monitoring progress. Daily weighing is not recommended because of the frequent fluctuations resulting from retained water (including urine) and elimination of faeces. The patient should be instructed to record the weight at the same time of the day, wearing the same type of clothing.

There is no firm agreement on the number of meals to be eaten when a person is on a diet. Some nutritionists advocate several small meals per day because the body’s metabolic rate is temporarily increased immediately after eating. When several small meals a day are ingested, more kilojoules are used. There seems to be general agreement that consumption of most of the daily kilojoule intake at a large evening meal results in less weight loss than when the kilojoules are evenly distributed throughout the day.

When a person is first starting on a weight-reduction program, food portion sizes need to be carefully determined to stay within the dietary guidelines. Portion sizes over the past 20 years have increased considerably (Table 40-7).²⁵ Food portions can be weighed using a scale or everyday objects can be used as a visual cue to determine portion sizes. The size of a woman’s fist or tennis ball is equivalent to a serving of vegetables or fruit. A serving of meat is about the size of a human’s palm or a deck of cards. A serving of cheese is about the size of a thumb or six dice. The Portion Distortion website listed in the Resources (see p 1072) includes a test on portion sizes.

Another aspect of diet that needs to be considered is the proportion of kilojoules from animal sources and from fruits, grains and vegetables. The Healthy Living Pyramid (formerly The Healthy Eating Pyramid)²⁶ has been used in Australia and New Zealand for more than 30 years. Dietary guidelines in both New Zealand²⁷ and Australia²⁸ encourage people to eat a wide variety of nutritious foods, including plenty of vegetables, legumes, fruits, cereals and lean meat; moderate amounts of milk, yoghurt and cheese; and limited amounts of saturated fat and salt. Maintaining an awareness of personal consumption habits and striving for healthy eating is a simple goal that can be achieved without weighing and measuring foods at every meal. Once pyramid guidelines have been adopted into the patient’s meal planning, portions can gradually be reduced as activity levels are gradually increased to achieve healthy weight loss. The Australian recommended dietary intake for protein is 55 g per day for adults. The standard size for chopped vegetables is half a cup according to the food guide pyramid (see Ch 39).

A list of permitted foods serves as a good reference and allows an occasional meal to be eaten at a restaurant. The patient who carefully follows the prescribed diet may not need to take vitamin supplements. Appropriate fluid intake should be encouraged. Alcoholic beverages are usually not permitted on a reducing diet because they increase the kilojoule intake and are low in nutritional value.

EXERCISE

The Healthy Living Pyramid reflects the inclusion of exercise as an essential aspect of a healthy lifestyle and weight control. Exercise should be done daily, preferably for 30–60 minutes a day. There is no evidence that increased activity promotes an increase in appetite or leads to dietary excess. In fact, exercise frequently has the opposite effect. The addition of exercise produces more weight loss than does dieting alone. Increasing exercise has a favourable effect on body fat distribution, with a reduction in the WHR. Exercise is especially important in maintaining weight loss in overweight and obese persons.

The nurse should explore with the patient possible ways to increase exercise in daily routines, such as parking further from work or taking the stairs. Individuals should be encouraged to wear a pedometer to track their activity. The goal is 10,000 steps per day, but a third of this with incremental increases is a good start.^5,⁸

Joining a health club can be one way of getting exercise. Walking, swimming and cycling are sensible forms of exercise and have long-term benefits. Engaging in weekend exercise only or in spurts of strenuous activity is not advantageous and can actually be dangerous. When large muscles are involved in the exercise program, a primary benefit is cardiovascular conditioning. Overweight men and women who are active and fit have lower rates of morbidity and mortality than overweight persons who are sedentary and unfit. Exercise is of benefit to overweight persons, even if it does not make them lean.

Many psychological benefits can be derived from an increased physical activity program. A reduction in tension and stress, better-quality sleep and rest, increased stamina and energy, improved self-concept and self-confidence, better attitudes towards work and play, and increased optimism about the future can all be achieved.

BEHAVIOUR MODIFICATION

The assumption behind behaviour modification is that obesity is a learned disorder caused by overeating and that the critical difference between an obese person and a non-obese person is in the cues that regulate eating behaviour. Therefore, most behaviour-modification programs de-emphasise the diet and focus on how and when the person eats. Participants are often taught to restrict their eating to designated meals and to increase the amount of physical activity in their lives. Persons who have undergone behaviour therapy are more successful in maintaining their losses over an extended time than are those who do not participate in such training.

Useful basic techniques include: (1) self-monitoring; (2) stimulus control; and (3) rewards. Self-monitoring can focus on a record that shows what and when foods are eaten, as well as how the person was feeling when the foods were consumed. Stimulus control is aimed at separating events that trigger eating from the act of eating. Rewards may be used as an incentive for weight loss. Short- and long-term goals are useful benchmarks for earning rewards. It is important that the reward for a specified weight loss not be associated with food, such as a dinner out or a favourite treat. Reward items do not need to have a monetary component. For example, time for a hot bath or an hour of pleasure reading would be an enjoyable reward for many people. People may participate in group or individual sessions, or both, as they work towards their goals.

SUPPORT GROUPS

The individual who is on any type of restrictive dietary program is often encouraged to join a group of other obese people who are receiving professional counselling to help them modify their eating habits. Many self-help groups are available to those who want to learn more about successful dieting and who like having the support of others with the same problems and experiences. Behavioural modification is an integral part of the program, along with nutrition education. WeightWatchers International Inc. is probably the most successful commercial weight-reduction enterprise. WeightWatchers offers a food plan that is nutritionally balanced and practical to follow, and it has used behaviour-modification techniques since 1974.

There has been a proliferation of commercial weight-reduction centres across Australia and New Zealand. Many of these programs are staffed by nurses or dieticians, or both, and require an initial physical examination by a healthcare provider before a candidate is accepted for a weight reduction program. These weight-reduction centres are costly and are therefore cost prohibitive for those with limited financial resources. Many of these programs also offer special prepackaged foods and supplements that must be purchased as part of the weight-reduction plan. Only these prescribed foods and drinks are to be consumed until an agreed-on amount of weight is lost. The patient is encouraged to buy the same type of foods for the maintenance phase of the program, lasting from 6 months to 1 year. Behaviour-modification training is incorporated within these programs as well.

Are psychological interventions effective in helping overweight individuals to lose weight?

EVIDENCE-BASED PRACTICE

DRUG THERAPY

Drugs have been used in the treatment of obesity but only as adjuncts to a good diet and exercise program. Drugs that are approved for weight loss can be classified into two categories: (1) those that decrease food intake by reducing appetite or increasing satiety (sense of feeling full after eating); and (2) those that decrease nutrient absorption. Drugs that increase energy expenditure (e.g. adrenaline) are not approved for weight loss in Australia or New Zealand.

1. Appetite-suppressing drugs. Appetite suppressants reduce food intake through noradrenergic (drugs that mimic noradrenaline) or serotonergic mechanisms in the CNS. Noradrenergic agents include phentermine and diethylpropion. Amphetamines, such as benzphetamine, are not recommended because of their abuse potential. Adverse effects of these drugs include palpitations, tachycardia, overstimulation, restlessness, dizziness, insomnia, weakness and fatigue.^29,³⁰

Serotonergic drugs act to either increase the release of serotonin or decrease its uptake, thus reducing its metabolism. Fenfluramine and dexfenfluramine were the first drugs in this class. However, in 1997 these drugs were withdrawn from the market because of reported adverse effects (e.g. valvular heart disease, pulmonary hypertension). These drugs are mentioned to advise patients that their use is dangerous.

Mixed noradrenergic–serotonergic agents were also used in weight management. Sibutramine inhibits both serotonin and noradrenaline uptake, thus increasing their levels in the CNS. Sibutramine, along with a reduced-kilojoule diet, has been shown to reduce body weight. Side effects of sibutramine include increased blood pressure and heart rate, dry mouth, headache, insomnia and constipation. Like other pharmacotherapies, sibutramine has been withdrawn from the market due to safety concerns.³¹ Other selective serotonin-reuptake inhibitors that are approved for the management of depression and other psychiatric conditions may have a short-term effect on weight loss but the effect does not appear to last over time.

2. Nutrient absorption-blocking drugs. Orlistat, a drug that was developed for weight loss and maintenance, works by blocking fat breakdown and absorption in the intestine. It inhibits the action of intestinal lipases. The undigested fat is excreted in the faeces. Although this drug has a high safety profile, some fat-soluble vitamin levels may decrease and may need to be supplemented. Orlistat is associated with leakage of stool, flatulence, diarrhoea and abdominal bloating, which are accentuated if a high-fat diet is consumed.³² These side effects limit its acceptance as a weight loss tool.

Because drugs will not cure obesity without substantial changes in food intake and increased physical activity, weight gain will occur when short-term drug therapy is stopped. Supervised long-term drug therapy with safe compounds can contribute to weight management as well as weight loss. As with any pharmacological treatment, there are side effects. Careful evaluation for the presence of other medical conditions can help determine which drugs, if any, would be advisable for a given patient.

The role of the nurse in relation to drug therapy should centre on teaching the patient about proper administration and side effects, and how the drugs fit into the larger weight loss plan. The modification of dosage without consultation with the healthcare provider can have detrimental effects. The nurse should re-emphasise that diet and exercise regimens are the cornerstones of permanent weight loss. Drugs may be helpful but they do not help the patient change eating behaviour. The purchase of over-the-counter diet aids should be discouraged.

Even with a comprehensive action plan, there is a high rate of weight regain among all age groups. For successful management of obesity, the nurse remains in a pivotal position to reinforce that obesity is a chronic condition that necessitates day-to-day attention to maintain weight loss.

Collaborative surgical therapy

Bariatric surgery is a surgical procedure that is used to treat morbid obesity. It is currently the only treatment that has been found to have a successful and lasting impact for sustained weight loss for severely obese individuals.³³ The majority of patients who undergo bariatric surgery have successfully improved their overall quality of life. A great deal of excess weight is lost, and patients experience resolution of comorbidities and improve their appearance, social opportunities and economic opportunities.³³ It is particularly effective against type 2 diabetes mellitus, with one meta-analysis reporting an overall weight loss of 38.5 kg, and that complete remission of type 2 diabetes occurred in 78.1% of patients.³⁴

An individual needs to meet all of the following to be considered for bariatric surgery:

Do obese patients undergoing surgery have increased cardiovascular risks?

EVIDENCE-BASED PRACTICE

Clinical question

For adults undergoing surgery (P), does obesity (I) lead to increased cardiovascular risks (O) during the preoperative, intraoperative and postoperative phases (T)?

Best available evidence

• Clinical practice guidelines based on review of randomised controlled trials (RCTs) and meta-analyses

Conclusion

• There are significant cardiovascular risks for severely obese adults undergoing surgery during the preoperative, intraoperative and postoperative phases of care.

Reference for evidence

Poirier P, Alpert MA, Fleisher LA, et al. Cardiovascular evaluation and management of severely obese patients undergoing surgery: a science advisory from the American Heart Association. Circulation. 2009;120:86.

Patients are not good candidates for bariatric surgery if they are obese from a treatable disorder such as hypothyroidism, have a substance abuse problem or have a major psychiatric disorder.

Bariatric surgery falls into one of three broad categories: restrictive, malabsorptive or a combination of malabsorption and restrictive (see Table 40-8 and Fig 40-6). In restrictive procedures the stomach is reduced in size, and in malabsorptive procedures the length of the small intestine is decreased. Up until 2009 in Australia and 2010 in New Zealand bariatric surgery was available only in private hospitals, but now it is publicly funded in both countries.

TABLE 40-8 Surgical interventions for morbid obesity

GI, gastrointestinal.

Figure 40-6 Bariatric surgical procedures. A, Vertical banded gastroplasty, which involves creating a small gastric pouch. B, Adjustable gastric banding uses a band to create a gastric pouch. C, Biliopancreatic diversion with duodenal switch procedure, which creates an anastomosis between the stomach and intestine. D, Roux-en-Y gastric bypass procedure, which involves constructing a gastric pouch whose outlet is a Y-shaped limb of small intestine.

GASTRIC RESTRICTIVE SURGERY

Restrictive bariatric surgery reduces the size of the stomach to 30 mL or less, which causes the patient to feel full more quickly.³⁴ The stomach and intestines digest and absorb food normally when restrictive gastrointestinal surgery is performed. Since digestion is not altered, the risk of anaemia or vitamin B₁₂ deficiency is low.

VERTICAL BANDED GASTROPLASTY

Vertical banded gastroplasty (VBG) involves partitioning the stomach into a small pouch in the upper portion along the lesser curvature of the stomach. This small pouch drastically limits capacity. In addition, the stoma opening to the rest of the stomach is banded to delay emptying of solid food from the proximal pouch. This procedure has achieved considerable success in the management of weight loss. Problems associated with this gastric restriction operation include intractable vomiting from too rapid an intake of solids, distension of the wall of the proximal pouch, rupture of the staple line and erosion of the band into the stomach.

ADJUSTABLE GASTRIC BANDING

With adjustable gastric banding (ABG), the stomach size is limited by an inflatable band placed around the fundus of the stomach. This is the newest restrictive procedure and is often referred to as the LAP-BAND system. The band is connected to a subcutaneous port and can be inflated or deflated (by fluid injection in the doctor’s surgery) to change the stoma size to meet the patient’s needs as weight is lost.³¹ The procedure can be done laparoscopically and can be modified or reversed after the initial procedure. ABG can be a better choice for patients who are surgical risks since it is a less invasive approach.

Weight loss is slower in patients who undergo ABG as compared to other procedures. Other disadvantages to this procedure are that the band may slip or erode into the stomach wall. Another operation would be needed to correct this problem.

GASTRIC MALABSORPTIVE SURGERIES

If a patient chooses to have malabsorptive surgery to reduce their weight, the surgeon will bypass various lengths of the small intestine so that less food is absorbed.

Biliopancreatic diversion

Biliopancreatic diversion (BPD) involves removing approximately three-quarters of the stomach to produce both restriction of food intake and reduction of acid output. The remaining portion of the stomach is connected to the lower portion of the small intestine. Pancreatic enzymes and bile enter the final segment of the small intestine. Nutrients pass without being digested. The patient loses weight because most of the kilojoules and nutrients are routed into the colon, where they are not absorbed.

This procedure can increase the risk of gallstones forming and may require the gall bladder to be removed. Patients should be aware of the possibilities of intestinal irritation and ulcers. Other risks from BPD include abdominal bloating and foul-smelling stool or gas. There is also a period during which the intestines adjust and bowel movements can be very liquid and frequent. This condition may lessen over time but may be a lifelong condition. Patients should also monitor their protein, iron and vitamin B₁₂ intake to ensure that they do not develop malnutrition or anaemia. Supplements and vitamins should be taken to offset these risks.

Biliopancreatic diversion with duodenal switch

This is a variation of the BPD procedure. By including a duodenal switch, the surgeon can leave a larger portion of the stomach intact. This procedure also lets the surgeon keep the pyloric valve, which helps prevent dumping syndrome. (Dumping syndrome is discussed below.) A small part of the duodenum is also kept.

COMBINATION OF GASTRIC RESTRICTIVE AND MALABSORPTIVE SURGERY

Roux-en-Y surgical procedure

The Roux-en-Y gastric bypass procedure is a combination of restrictive and malabsorptive surgery.³⁵ This surgical procedure has low complication rates and excellent patient tolerance and has proven to sustain long-term weight loss. Because of this, the procedure is the most commonly used bariatric surgery. In this procedure, the stomach size is decreased with a gastric pouch anastomosis that empties directly into the jejunum. This surgery can be performed through an open abdominal incision or laparoscopically. Variations of this procedure include: (1) stapling the stomach without transection to create a small, 20- to 30-mL gastric pouch; (2) creating an upper and a lower gastric pouch and totally disconnecting the pouches; and (3) creating an upper gastric pouch and completely removing the lower pouch. After the procedure, food bypasses 90% of the stomach, duodenum and a small segment of jejunum.

The greatest rate of weight loss is usually achieved after the first year following surgery. Weight tends to stabilise after 18 months. Outcomes include increased glucose tolerance, decreased diabetes, decreased blood pressure, decreased cholesterol and triglyceride levels, decreased GORD and decreased sleep apnoea. Adverse outcomes include iron deficiency, vitamin B₁₂ deficiency, folic acid deficiency, calcium deficiency and increased homocysteine levels.³⁵ The use of robotics during Roux-en-Y surgery has been shown to reduce both morbidity and mortality rates.³⁶

A complication of this procedure is dumping syndrome, in which the gastric contents empty too rapidly into the small intestine, overwhelming its ability to digest nutrients. Symptoms can include vomiting, nausea, weakness, sweating, faintness and, on occasion, diarrhoea. Some patients are unable to eat sugary foods after surgery. Because sections of the small intestine are bypassed, poor absorption of iron and calcium can cause iron-deficiency anaemia. Patients who experience chronic blood loss during excessive menstrual flow or bleeding haemorrhoids should be aware of the chance of iron-deficiency anaemia. By taking a multivitamin and calcium supplements, patients can maintain a healthy level of minerals and vitamins. Chronic anaemia due to vitamin B₁₂ deficiency may also occur. The problem usually can be managed with vitamin B₁₂ pills, injections or nasal spray.

COSMETIC SURGERIES TO REDUCE FATTY TISSUE AND SKINFOLDS

Lipectomy

Lipectomy (adipectomy) is performed to remove unsightly flabby folds of adipose tissue. The patient who chooses lipectomy does so for cosmetic reasons. In some patients, up to 15% of the total fat cells can be removed from the breasts, abdomen, and lumbar and femoral areas. There is no evidence that a regeneration of adipose tissue occurs at the surgical sites. However, it must be emphasised to the patient that surgical removal does not prevent obesity from recurring, especially if lifetime eating habits remain the same. Although body image and self-esteem may be enhanced by such procedures, these operations are not without complications. The dangerous effects of anaesthesia and the potential for poor wound healing in the obese patient cannot be overemphasised. It is more useful for the majority of patients contemplating a lipectomy to be instructed in preventative health measures, such as slow weight reduction to maintain and preserve tissue integrity, the value of exercise and behaviour-modification techniques.

Liposuction

Another surgical procedure is liposuction, or suction-assisted lipectomy. The current use is for cosmetic purposes and not for weight reduction. This surgical intervention helps improve facial appearance or body contours. A good candidate for this type of surgery is a person who has achieved weight reduction but who has excess fat under the chin, along the jaw line, in the nasolabial folds, over the abdomen, or around the waist and upper thighs. The procedure is relatively free of major complications. A long, hollow, stainless steel cannula is inserted through a small incision over the fatty tissue to be suctioned. The purpose of this type of surgery is to improve body appearance, thereby enhancing body image and self-concept. It is not usually recommended for the older person because the skin is less elastic and will not accommodate the new underlying shape.

NURSING MANAGEMENT: THE OBESE PATIENT UNDERGOING SURGERY

Nursing implementation

This section discusses general nursing considerations for the care of the obese patient who is having surgery. Special nursing considerations are described for the patient who is having bariatric surgery. (Care of the surgical patient is discussed in Chs 17–19 Ch 18 Ch 19.)

Patients with a BMI of >30 kg/m² often have several other medical conditions that are related to obesity that increase their surgical risk factors. These medical conditions affect the care of the obese patient before, during and after surgery.

Preoperative care

Special considerations are necessary in the care of the patient who is admitted to the hospital for surgical treatment, especially the morbidly obese. Prior to surgery, it is important that an interview is conducted with the patient. The primary reasons for this preoperative interview are to obtain past and current patient health information and to ensure that the patient understands the surgical procedure that they are scheduled to undergo. Patients who are obese are likely to suffer from other comorbidities, including diabetes, altered cardiorespiratory function, abnormal metabolic function, haemostasis and atherosclerosis.³⁷ A team approach to treatment of the obese patient may be necessary. If the patient suffers from a disease other than obesity, it may be necessary to coordinate with the patient’s cardiologist, respiratory doctor, gynaecologist, gastroenterologist or other specialists to address concerns related to any other medical problems that the patient may have.

To ensure the patient’s dignity and privacy, the nursing team should have the room prepared and supplies ready before the patient arrives. Most nursing units are not prepared to meet the needs of a patient who is often too large for a typical hospital or recovery room bed or who has arms that even a large-size blood pressure cuff will not fit.³⁸ To eliminate embarrassment for the patient and frustration for the staff, plans for these special needs should be made before the patient’s admission. Oversized blood pressure cuffs should be ready for use when the patient arrives. A private room may be necessary for privacy of the patient and to accommodate the bed and sitting arrangements. A strongly reinforced trapeze bar should be placed over the bed to facilitate movement and positioning. In some cases specially constructed chairs and beds may need to be accessed or beds joined together to allow the patient to sit and sleep in comfort.

A care-planning conference should be a priority so that even simple nursing care measures do not become impossible tasks. Consideration should be given to questions such as how the patient will be weighed, how the patient will be transported throughout the hospital, and how simple physical assessment strategies may have to be adjusted to accommodate the morbidly obese patient. Another need is a wheelchair with removable arms that is large enough to safely accommodate the patient and pass easily through doorways.

Strategies for bathing, turning and ambulating the patient, including the number of extra people needed to carry out these measures, are invaluable when the actual need arises. Special gowns are also needed for the patient. Routine physical assessment strategies do not work well with morbidly obese patients, who have numerous layers of skinfolds covering areas that need to be assessed. Without identifying alternatives or unique methods of dealing with this problem, assessment of respiratory status and bowel sounds or even wound inspection could be awkward for the nurse and embarrassing for the patient.

Wound infection is one of the most common complications after surgery. Because of the many layers of flabby skinfolds, especially in the abdominal area, preoperative skin preparation is important. Frequently the patient is instructed to take several showers a day for a few days before admission to the hospital. Careful cleansing with soap and warm water of the abdominal area from the breasts to below the waist is emphasised.

Obesity can cause a patient’s breathing to become shallow and rapid. The extra adipose tissue in the chest and abdomen compresses the diaphragmatic, thoracic and abdominal structures. This compression restricts the chest’s ability to expand, causing the lungs to not work as efficiently as they would otherwise. Thus, the patient retains more carbon monoxide. The increase of carbon monoxide in the patient’s body can lead to hypoxaemia, pulmonary hypertension and polycythaemia. The patient must be instructed in the proper coughing technique, deep breathing, and methods of turning and positioning to prevent pulmonary complications after surgery. The use of a spirometer may be introduced before surgery. Use of the spirometer helps prevent and alleviate postoperative lung congestion. Practising these strategies preoperatively can aid in performing them correctly postoperatively.

Obtaining venous access may also be complicated by excess adipose tissue. An assistant may be needed to help. If a patient has pitting oedema, or excess fat, the nurse should hold a firm finger over the spot with pressure. It may be helpful to mark the spot of injection with a sterile skin marker once a vein is found. Oedema can become worse if the catheter is anchored by taping the arm. This action can further impede venous return, causing venous stasis, pooling of intravenous fluids, extravasation or infiltration. The nurse may also want to use multiple tourniquets to distend veins and hold back excess tissue. The tourniquet should be removed as soon as it is no longer needed to avoid aggravating the oedema. A longer catheter (longer than 3 cm) may be needed to traverse overlying tissue. It is important that the cannula is far enough into the vein to ensure that it is not dislodged or infiltrated.

If the patient is to undergo anaesthesia during surgery, the anaesthetist should inform the patient about the increased risk of failure to wean from mechanical ventilation. This risk is important for patients to know so that they are aware of what to expect when they wake up from the anaesthesia.

Special considerations for bariatric surgery

All patients admitted for major gastric surgery procedures have a nasogastric (NG) tube inserted during surgery and attached to low suction after surgery. A good method of involving patients in the plan of care is to allow them to see a typical tube and explain why it is necessary. The patient should know that oral nourishment will be impossible for a few days after the surgery and that intravenous fluids will be the main source of intake.

Postoperative care

Trained staff members should assist with the transfer of the unconscious patient. The transfer may require up to five trained staff members. During the transfer, the patient’s airway should remain stabilised and attention should be given to maintaining pain at a manageable level. The patient’s head should be maintained at a 35– 40° angle to reduce abdominal pressure and increase tidal flow. If the patient is severely obese, the nursing team should closely monitor the patient for rapid oxygen desaturation.³⁹ The body stores anaesthetics in adipose tissue, placing patients with excess adipose tissue at risk of resedation. As adipose cells release the anaesthetic back into the bloodstream, the patient may become sedated after surgery. If this happens, the nursing care team should be prepared to perform a head-tilt or jaw thrust manoeuvre and keep the patient’s oral and nasal airways opened.

Early ambulation is essential for the obese patient.³⁹ It is important that the patient knows that it is usually necessary to get out of bed soon after surgery and with increasing frequency thereafter, generally three to four times each day. Education regarding the dangers of thrombophlebitis and measures to counteract its development are a routine part of preoperative teaching. The patient should know that elastic stockings, pneumatic compression devices, elastic compression stockings or elastic wraps will be applied to the legs and that active and passive range-of-motion exercises will be a frequent part of daily care. Low-dose heparin will often be ordered. Depending on the patient’s size and the amount of pain the patient is experiencing, the patient may not be able to assist the nurse in turning and extra nurses may be needed to turn the patient safely.

The nursing care team will also want to access the patient’s skin for delayed wound healing, the development of seromas, haematomas, wound dehiscence, wound evisceration or wound infection.^38,³⁹ Skinfolds should be kept clean and dry to prevent dermatitis and secondary bacterial or fungal infections.

Special considerations for bariatric surgery

The patient will experience considerable abdominal pain after surgery. Administration of pain medications should be given as frequently as necessary during the immediate postoperative period. Encouraging and assisting the patient to turn, cough and deep breathe at least every 1–2 hours minimises the risk of atelectasis and pneumonia. Frequent mouth and nose care also helps breathing efforts because the NG tube is inserted through one nostril.

Position changes and range-of-motion exercises are instituted immediately after surgery and carried out every 1–2 hours. Ambulatory efforts are generally begun on the evening of surgery. For patient safety, the nurse should enlist the assistance of other staff members during these initial efforts, while encouraging the patient to help.

The abdominal wound requires frequent observation for the amount and type of drainage, the condition of the sutures and signs of infection. The incision must be protected against undue straining that accompanies turning and coughing. Wound dehiscence and wound healing are potential problems for all obese patients. Monitoring the vital signs assists in identifying problems such as infection.

It is important that the NG tube be kept patent and in the correct position. Vomiting is common following gastric procedures. If tube patency is blocked or the tube requires repositioning, the doctor should be notified at once. The upper gastric pouch is small, and irrigating the tube with too much solution or manipulating the tube position can lead to disruption of the anastomosis or staple line. In most cases the NG tube can be removed in approximately 48 hours, or when bowel sounds have resumed.

Skin care should be carried out several times during each shift. Perspiration may be excessive at times. The many layers of skin should be kept clean and dry so that this source of irritation is eliminated. For the patient who has an indwelling catheter, perineal care is important so that a urinary tract infection can be prevented.

During the immediate postoperative period (first 24 hours) water and sugar-free clear liquids are given (30 mL every 2 hours while awake) when tolerance is established. At 1 day to 2 weeks postoperatively a high-protein liquid diet (e.g. 30–60 mL Boost HP, Ensure Plus, Carnation Instant Breakfast) is offered every 2 hours while awake. During this time fluid intake should be carefully monitored. At 2–4 weeks postoperatively a pureed diet is provided at frequent intervals. The patient is taught to eat slowly, to stop when feeling full and not to consume liquids with solid food. Vomiting is a common complication during this time. At 4–6 weeks the patient starts on a transition diet that includes solids as well as pureed foods.

Ambulatory and home care

Special considerations for bariatric surgery

The patient who has undergone major surgical treatment for obesity has not, in the past, been successful in following or maintaining a prescribed diet. Now the patient is forced to reduce their oral intake as a result of the anatomical changes brought about by the operation. The patient will find that adherence to a reduced intake is necessary because of the concern for abdominal distension, cramping abdominal pain and perhaps diarrhoea.

Weight loss is considerable during the first 6–12 months. It is during this time that the patient must learn to adjust intake sufficiently to maintain a stable weight. Although behaviour modification was not an intended outcome when these surgical procedures were devised, it becomes an unexpected secondary gain. The diet generally prescribed should be high in protein and low in carbohydrates, fat and roughage and consist of six small feedings daily. Fluids should not be ingested with the meal and, in some cases, fluids should be restricted to less than 1000 mL per day. Fluids and foods high in carbohydrate tend to promote diarrhoea and symptoms of dumping syndrome. Generally, kilojoule-dense foods (foods high in fat) should be avoided to permit more nutritionally sound food to be consumed.

Late complications can be anticipated after gastric bypass or gastroplasty, including anaemia, vitamin deficiencies, diarrhoea and psychiatric problems.^35,³⁹ Failure to lose weight or loss of too much weight may be caused by the surgical formation of too large a stomach pouch or an outlet that is much too small, respectively. Peptic ulcer formation, dumping syndrome and small bowel obstruction may be seen late in the recovery and rehabilitative stage.

Long-term follow-up care must be stressed, in part because of complications late in the recovery period. The patient must be encouraged to adhere strictly to the prescribed diet and to keep the healthcare provider informed of any changes in condition. Some patients have been known to overeat when they return home and gain rather than lose weight.

The nurse must anticipate and recognise several potential psychological problems after surgery. Some patients express guilt feelings concerning the fact that the only way they could lose weight was by surgical means rather than by the ‘sheer willpower’ of reduced dietary intake. The nurse should be ready to provide support so that the patient does not dwell on negative feelings. Many morbidly obese patients who blamed their feelings of social inferiority or inadequacies on their appearance before bypass surgery may suffer from episodes of depression. By 6–8 months after surgery, considerable weight loss will have occurred, and they will be able to see clearly how much their appearance has changed.

Massive weight loss often leaves patients with large quantities of flabby skin that can result in problems related to altered body image. Reconstructive surgery at least one full year after the initial surgery may alleviate this situation. Reduction of the breasts, upper arms, thighs and excess abdominal skinfolds are possible solutions. Discussion of this possible outcome with the patient before surgery and again during the rehabilitation phase of recovery helps facilitate the patient’s adjustment to a new body image and social reintegration.

Evaluation

The expected outcomes are that the obese patient will: (1) experience long-term weight loss; (2) have improvement in obesity-related comorbidities; (3) integrate healthy practices into daily routines; (4) monitor for adverse side effects of surgical therapy; and (5) have an improved self-image.

Gerontological considerations: obesity in older adults

The prevalence of obesity is increasing in all age groups, including older people. The number of obese older people has risen markedly because of an increase in both the total number of older people and the percentage of older adults who are obese. A decrease in energy expenditure is an important contributor to a gradual increase in body fat with increasing age.

Obesity in older adults can exacerbate age-related declines in physical function and lead to frailty and disability.⁴⁰ Obesity is associated with decreased survival. Individuals who are obese live 6–7 years less than people of normal weight.¹⁷

Arthritis is a leading cause of physical disability in older adults. The age-related increase in the prevalence of osteoarthritis reflects body changes related to a lifetime of being overweight, which results in mechanical strain on weight-bearing joints.⁴⁰ Pulmonary complications of obesity, such as hypoventilation syndrome and obstructive sleep apnoea, are a major problem for older adults. Older obese men are especially predisposed to develop weight-related sleep apnoea.

Obesity contributes to the increase in prevalence of urinary incontinence in older people. In addition, obesity is associated with an increased risk of several types of cancers that occur more commonly in older adults, including breast, colorectal, gall bladder, endometrial and prostate cancers.

Obesity impacts on the quality of life for older adults. Weight loss can improve quality of life, physical function and obesity-related health complications. The same therapeutic approaches for obesity as were discussed earlier also apply to the older adult.

Metabolic syndrome

Metabolic syndrome, also known as syndrome X, insulin resistance syndrome and dysmetabolic syndrome, is a collection of risk factors that increase an individual’s chance of developing cardiovascular disease and diabetes mellitus. Metabolic syndrome is diagnosed if an individual has three or more of the conditions listed in Table 40-9.⁴¹

TABLE 40-9 Diagnostic criteria for metabolic syndrome ^*

BP, blood pressure.

* Any 3 of the 5 measures are needed for a diagnosis of metabolic syndrome.

Source: Grundy S, Cleeman JI, Daniels SR et al. Diagnosis and management of the metabolic syndrome: an American Heart Association/National Heart, Lung, and Blood Institute Scientific Statement. Cardiol Rev 2005; 13:322–327.

AETIOLOGY AND PATHOPHYSIOLOGY

The main underlying risk factors for metabolic syndrome are abdominal obesity and insulin resistance. Other conditions associated with the syndrome include physical inactivity, the presence of inflammatory markers, prothrombotic tendencies, hormonal imbalance, ageing and genetic or ethnic predisposition. (Fig 40-7 illustrates the relationships between the various factors.) The prevalence of this syndrome is rising in both Australia and New Zealand, with increasing evidence that some ethnic groups may be affected differently from others. It has been suggested in the literature that Asians and Indigenous Australians, as well as women who have had gestational diabetes, are at particular risk of developing metabolic syndrome.^42,⁴³ Pacific Islander and Māori populations in New Zealand have also been shown to have higher levels of metabolic syndrome.⁴² This is an area that needs further study, as a number of diagnostic criteria are available.⁴³ Patients who have been diagnosed with metabolic syndrome typically have diabetes and cannot maintain a proper level of blood glucose, have hypertension and secrete a large amount of insulin, or have survived a heart attack and have hyperinsulinaemia.⁴⁴

Figure 40-7 Relationship between insulin resistance, obesity, diabetes mellitus and cardiovascular disease.

Although there are no symptoms of metabolic syndrome, medical problems will develop over time if the condition remains undetected. Patients with the syndrome are at a higher risk of developing heart disease, stroke, diabetes and renal disease. Patients who have metabolic syndrome and who smoke are at an even higher risk.

NURSING AND COLLABORATIVE MANAGEMENT: METABOLIC SYNDROME

Lifestyle therapies are the first-line intervention to reduce the risk factors for metabolic syndrome,⁴⁵ and nurses can assist patients by providing information on healthy diets, exercise and positive lifestyle changes. A recent meta-analysis that examined data from more than 35 clinical trials and 500,000 participants concluded that a diet high in monounsaturated fatty acids, fruits, vegetables, wholegrain cereals and low-fat dairy products, coupled with fish, poultry, nuts, legumes and a low consumption of red meat (the Mediterranean diet), is associated with a lower prevalence and slower progression of metabolic syndrome.⁴⁶ In addition, adhering to the diet also had favourable effects on individual components of the metabolic syndrome, including waist circumference, HDL-cholesterol and triglyceride levels, blood pressure and glucose metabolism. The study authors concluded that management or reversal of metabolic syndrome can be achieved by reducing the major risk factors of cardiovascular disease: reducing LDL cholesterol levels, stopping smoking, lowering blood pressure and reducing blood glucose levels. For long-term reduction in risk, weight should be decreased to a desirable level, physical activity should be increased and healthy dietary habits should be established.^12,⁴⁵

Since a sedentary lifestyle contributes to metabolic syndrome, increasing regular physical activity will lower a patient’s risk factors. A sedentary lifestyle is defined as ‘one in which demanding physical activity does not exceed 20-minute sessions or when such activity occurs fewer than three times per week’.²² As well as assisting in weight reduction, regular exercise has been found to normalise the elevated triglyceride levels and the relatively lower HDL cholesterol levels that are seen in metabolic syndrome.^22,⁴⁵

Patients who are unable to lower risk factors with lifestyle therapies alone or who are at high risk of a coronary event may be considered for drug therapy. Although no medication is available specifically for metabolic syndrome, medication can be prescribed to lower individual risk factors, such as metformin for reducing blood glucose levels.

The obese patient

CASE STUDY