The Origins of the ICU

For intensive care doctors, covid-nineteen offers an eerily similar look at how doctors sixty years ago fought to save patients from another viral disease, polio. And this shared experience is poignant because that's when intensive care medicine was born, thanks to a Danish doctor.

Bj'rn Ibsen had a bold idea for giving patients air using mechanical ventilation, the precursor to the modern ventilator. Polio can paralyze chest muscles making it hard to breathe. At the time, patients were placed inside negative pressure boxes while their heads stuck out in order to allow their chest to relax, expand, and improve breathing. They were known as iron lungs but some people still died from respiratory failure.

Ibsen had a better idea. He wanted to apply not negative but positive air pressure directly into the lungs then allow the body to exhale normally. To do this, they made a cut at the neck, inserted a tube into the windpipe and attached a rubber bag to be pumped manually. The bag was attached to a tank of fifty percent oxygen and nitrogen, and a soda lime container removed carbon dioxide.

If carbon dioxide isn't dispelled, acid can build up in the blood and cause organ failure. Turns out, this killed some polio patients, but Ibsen's invention solves that problem. Today's ventilators are able to deliver the right amount of air and pressure and they save lives.