This is an urgent request triggered by an actual situation. After an incidental pneumonectomy, a woman now 72 years old, suffering from longstanding COPD combined with a restrictive lung disease du to secondary deformations of the thoracic cage, remains fully conscious and mentally undisturbed while intubated and under mechanical ventilation. She is neither prepared to nor intends to die. Apparently, her respiratory center is highly dysfunctional but does not appear to be completely knocked out.
Would it be possible.
a) to stimulate the respiratory center by narrowly balancing the hypoxia and hypercapnia tolerance with special ventilator settings?
b) to directly stimulate the respiratory center?
The best alternative for long term breathing support is a Drinker apparatus (iron lung). Few of them are available nowadays. First I would try “permissive hypercapnia”. It’s perfectly safe and harmless at levels as high as 150 torr provided she is breathing 100% oxygen. Just place her on 100% oxygen and shut off the ventilator, and wait for her normal metabolism to elevate her body reserves of carbon dioxide until it rises high enough to stimulate effective respiratory drive. This is called “apneic oxygenation.” She probably lived with hypercarbia before she got sick, and you have over-ventilated her and paralyzed her respiratory chemoreceptors. When she starts breathing you can lower the inhaled oxygen concentration to maintain the pulse oximeter reading at 89, at which point her hemoglobin will still be fully saturated and oxygen toxicity will be minimized. Don’t forget to remove the soda lime. It serves no purpose and is potentially harmful. Also, I recommend reading my book “50 Years Lost in Medical Advance: The Discovery of Hans Selye’s Stress Mechanism” that is available on Amazon. It will provide you with better ways to manage COVID and other forms of critical illness (all of which are caused by extreme stress mechanism hyperactivity)
there is a mini-iron lung system-fits around the rib cage and operates like the old iron lungs--sounds like something might work-the advantages is that its non-invasive and so reduces risk of infection, the bad news is it doesnt take the place of normal-tends to be a bit weak-so need to do something for sigh breaths occasionally to prevent atelectasis in bases- but could be a good option-if used with other modalities
The follow up of the particular case that motivated my question has been spectacular. The crucial element was chronic malnutrition. Since the patient was adamant in her will to survive, eventually renutrition was started through an endoscopically placed gastrostomy tube. Within 4 weeks, partial weaning was accomplished. The patient was transferred to a. geriatric ward and after continued rehabilitation over 6 months was eventually able to move freely and finally to resume normal peroral nutrition and social activities. Minimal residual cognitive deficits were observed.