medical advances
Ventilators: where’s the bottleneck?

In the scramble to build/acquire/commandeer ventilators the question arises: is the equipment the bottleneck or are other complementary facilities and trained technical and medical personnel to install and operate etc? Surely ventilators arent like band aids or inhalers that patients can use by themselves.

I put this to a friend who has developed ventilators (and studied their operation in hospitals to tweak the parameters of his designs).  He responded:

For COVID patients you have to blend oxygen with the air. Sometimes you end up giving almost 100% oxygen based on the severity. Most COVID patients have to be sedated, and ventilation is provided by a trained respiration therapist or pulmonologist. have to be careful about using excessive pressures, otherwise, there will be a decrease in pulmonary venous flow, which will cause hypotension. A low BP also affects coronary flow and in a damaged heart, can cause Arrhythmias. COVID attacks the heart muscle, and can weaken a damaged heart. Careful monitoring of the patient is necessary, especially, if the ventilator is in the flow mode. Columbia and NY Presbyterian generated protocols for multiplexing ventilators and that can add more complexity if two patients are using the same ventilator. If anyone tells you that you can operate a ventilator on COVID patients without proper training, its similar to flying a plane ( I am a CFII) under instrument conditions without proper ratings.

Another friend concurs:

You and I would be a danger to life if we tried to monitor a ventilator. And we are a long way from meeting that need. My wife, who runs an exec recruiting team for a very big hospital organization, is looking hard for respiratory experts. Not surprisingly, few are looking for new jobs today…

A third compares it to the situation in WW II when pilot shortages limited the planes that could be flown…

The ventilator developing friend further points out:

The lungs tend to adapt to ventilation and weaning a patient who has been on a ventilator for two weeks or more becomes difficult. The long term prognosis is not that great after weaning.. Furthermore, high pressures that may be necessary for compromised lungs put pressure on the heart, especially on the pulmonary circulation. Furthermore, an extended stay in the hospital may give rise to infections and long PTTs (clotting factors). Most COVID patients have to be sedated or paralyzed, since in advanced stages, assisted breathing may become difficult.

You may also end up with end stage renal disease, with bad prognosis. My late mother, was in Cleveland clinic in 2005. She was already in dialysis, before her heart surgery and while she was on ventilation her dialysis became problematic. They tried to wean her off after 3 weeks and she did not survive for more than an hour after extubation.

As a pulmonologist friend, morbidly, remarked that in long term ventilation we are often keeping corpses alive.”

Another friend says in doc speak, “going on the ventilator” means “buying time for the family to fly in.”

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