Anaesthesia following renal transplantation
Renal transplantation is becoming ever more common, with over 2800 renal transplants performed in 2011/12. Graft and patient survival following this operation continues to improve, therefore it is not uncommon for these patients to present for elective or emergency surgery in non-transplant centres. They are a patient population who may have significant comorbidities, either as a cause or result of their long-standing renal failure that necessitated renal transplantation. Issues to consider, specific to the transplant recipient preoperatively, include:
1 Graft function
2 Evidence of rejection
3 Immunosuppression regimen and side effects
4 Evidence of end-organ damage, either as a result of the disease process or due to immunosuppression.
1 Acknowledge the potential complications in transplant recipients presenting for an unrelated surgery
2 Ensure the graft function is assessed preoperatively
3 Employ an appropriate plan for the delivery of immunosuppressive therapies through the perioperative period.
2A03
A 56-year-old man, who had a renal transplant 3 years ago for renal failure secondary to glomerulonephritis, presents for elective right hemicolectomy for colonic carcinoma. He has a history of hypertension secondary to end-stage renal failure and takes atenolol and lisinopril. His other medications include simvastatin, aspirin, and an immunosupppression regimen of prednisolone, mycophenolate mofetil (MMF), and tacrolimus.
◆ Evaluation of transplanted organ function
◆ Exclude rejection
◆ Exclude infection
◆ Evaluation of end-organ damage, secondary to either complications of renal failure or the side effects of immunosuppression
◆ Other side effects of immunosuppression.
◆ Deteriorating organ function
◆ Non-specific symptoms, fatigue, general malaise.
◆ Renal function since transplant
◆ Episodes of rejection
◆ Need for dialysis
◆ Presence of a working fistula.
◆ FBC, U&E, LFTs, phosphate, magnesium, glucose, coagulation screen, urinalysis, ECG.
Basic laboratory investigations results include:
◆ Hb 110g/L, WCC 4.1, Plt 135
◆ Na+ 137, K+ 4.5, urea 7.4, Cr 154
◆ Urinalysis normal
◆ ECG sinus rhythm, LV hypertrophy.
◆ Continue the normal immunosuppression regimen
◆ Change from oral to IV route, if required
◆ Drug levels will need to be monitored if significant blood loss or fluid shifts are observed.
The anaesthetic technique used should ensure an adequate perfusion of the transplanted kidney. Immunosuppressive drugs may modify the effects of many drugs used in anaesthesia, including muscle relaxants; therefore, monitoring of neuromuscular blockade is essential.
Invasive monitoring is not essential and is only necessary if the type of surgery or the patient’s clinical status demands it. Immunosuppressed patients are more prone to infection; therefore, attention to strict asepsis during line insertion is essential, and all lines should be removed as soon as possible.
◆ Multimodal technique
◆ Avoid NSAIDs
◆ Epidural is not contraindicated, but again attention to an aseptic technique, normal coagulation, and platelet function
◆ Morphine or fentanyl PCA.
◆ Ensure adequate filling and perfusion of graft
◆ Ensure immunosuppression is maintained; monitor levels, and have a high index of suspicion of toxicity, especially if the renal function deteriorates
◆ Remove all invasive monitoring as soon as possible
◆ DVT prophylaxis and early mobilization, as a hypercoagulable state may exist.
Successes with public awareness campaigns and advances in transplantation techniques will result in increasing numbers of transplant recipients presenting for unrelated elective and emergency surgery in the future. A key consideration is the assessment of graft function during preoperative consultation. Renal graft function is assessed by adequacy of urine output and improving or stable biochemistry. Graft rejection may present as deteriorating biochemistry or as minimal non-specific symptoms such as lethargy or fatigue.
All patients will be immunosuppressed; the regimen will vary slightly from centre to centre, but it is imperative that this is continued in the perioperative period. Change of route of administration may be required, as may measurements of therapeutic levels, especially in surgery where there are significant fluid shifts or blood loss. Ciclosporin should be given 4–7 hours preoperatively.
The side effects of immunosuppression therapies are listed in Table 11.1, but, in addition, these patients are more susceptible to infections, including opportunistic infections, and have an increased incidence of malignancy, including post-transplant lymphoproliferative disorder.
Table 11.1 Side effects of immunosuppressive therapies
| Immunosuppressant agent | Side effect |
|---|---|
|
Steroid |
Hypertension, hyperlipidaemia, diabetes, neurotoxicity |
|
Azathioprine |
Bone marrow suppression, hepatotoxicity, pancreatitis |
|
Ciclosporin |
Nephrotoxicity, neurotoxicity, hypertension, hyperlipidaemia, diabetes, hypomagnesaemia, hyperkalaemia, gingival hyperplasia |
|
MMF |
Bone marrow suppression, GI disturbance |
|
Tacrolimus |
Nephrotoxicity, neurotoxicity, hypertension, hyperlipidaemia, diabetes, hypomagnesaemia, hyperkalaemia |
|
Sirolimus |
Bone marrow suppression, hyperlipidaemia |
Adapted from Killenberg PG et al., Medical care of the liver transplant patient, Third edition, p. 509, Copyright 2006, with permission from Wiley.
Elective surgery should be deferred if an infection or a rejection is diagnosed preoperatively.
General or regional anaesthesia may be used, as indicated. If a regional technique is used, attention must be given to strict asepsis, platelet and coagulation function, and the effect of hypotension on graft perfusion. IV access can be challenging. Patient positioning is important, as these patients may have hyperparathyroidism and osteoporosis.
These patients are at slightly increased risk of aspiration; therefore, intubation should be considered. Orotracheal intubation is preferred, rather than the nasotracheal route, due to the increased risk of infection from the nasal flora.
Routine antibiotic prophylaxis is all that is necessary, and supplemental steroid is not usually required.
Monitoring of neuromuscular blockade is essential, as immunosuppression has a variable effect on the metabolism of muscle relaxants. Suxamethonium is safe, unless hyperkalaemic.
Invasive monitoring should only be used if dictated by the type of surgery or the patient’s clinical status. It should be removed as soon as possible, due to the increased risk of infection.
Ensure an adequate fluid status and renal perfusion pressure throughout the perioperative period, and avoid all potentially nephrotoxic drugs, e.g. NSAIDs. If a blood transfusion is required, leucocyte-depleted blood is preferred.
Summary
Patients who have had a renal transplant will usually have multiple comorbidities, related either to the disease process that necessitated the transplant, or the long-term effects of haemodialysis, or the side effects of immunosuppression. It is imperative that the graft function is assessed preoperatively. Transplant recipients are usually well known to the transplant centre where the transplant was performed and have regular follow-up. Information regarding patient and graft progress can easily be accessed by contacting the transplant unit, as can advise on all matters of perioperative management.
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Kostopanagiotou G, Sidiropoulou T, Pyrsopoulos N, et al. Anesthetic and perioperative management of intestinal and multivisceral allograft recipient in nontransplant surgery. Transplant International 2008, 21, 415–27.