QI have a character, a seventy-year-old man, who has severe emphysema and spends his days in a wheelchair plugged into an oxygen bottle. If my bad guy wanted to kill him and make it appear to be a suicide or an accident, how could he accomplish it? Could he simply remove or tamper with his oxygen bottle?
Simon Wood
Author of Paying the Piper
Bay Area, California
AIt is true that many emphysema sufferers require full-time oxygen and carry around small oxygen tanks or oxygen concentrators. Either way the amount of oxygen in the inspired air that the individual receives is slightly higher than it would be if he was just breathing room air. Removing his tank or concentrator or emptying his oxygen tank could indeed cause death, and it would be indistinguishable from an accident or a suicide.
Another way would be to increase the amount of oxygen he is breathing. Let me explain. People with emphysema and other forms of chronic obstructive pulmonary disease (COPD) are highly sensitive to oxygen inhalation. The physiology is extremely complex, but in a person with this medical condition, a very high oxygen level in the inspired air will severely depress the respiratory center in the brain stem. The person would become lethargic, sleepy, lapse into a coma, and die from asphyxia. This would be a more pleasant way of committing suicide since reducing the oxygen intake would cause extreme shortness of breath and distress before death, while increasing the oxygen intake would cause him to fall asleep, lapse into a coma, and die quietly.
If the villain returned to the scene and turned the oxygen tank back to a normal flow rate, there would be no way of determining the exact manner of death. That is, homicide, suicide, accident, and a natural death from COPD would look identical. The normal flow rate for oxygen tanks in this type of patient is around two liters per minute. Increasing it to four or five liters per minute could cause death in a few minutes or up to an hour.