Question to an anesthesiologist regarding intubation with FIO2 100
March 11, 2015 | 20,00 EUR | answered by Dr. med. Ralf Berg
Hello Dr. I have a general question regarding the ventilation of a patient.
Let's consider the following scenario: a patient experiences respiratory failure (high spinal anesthesia) and is ventilated with FIO2 100% until the acute life-threatening symptoms subside. I am now wondering how harmful high doses of pure oxygen at FIO2 100% really are. I mean, in terms of the risk of developing lung cancer later on. Or am I unnecessarily worried? I have read something alarming on the internet: FIO2 of 100% can affect or hinder cellular respiration and lead to DNA damage, releasing countless free radicals causing oxidative stress. Is a high FIO2 really very dangerous in terms of later developing lung cancer? Do I now have to live in fear of developing lung cancer because I was once ventilated with 100% pure oxygen? Or is oxidative stress only temporary, as cells constantly regenerate, making my concern unwarranted? How does a 100% pure oxygen delivery compare to smoking cigarettes? Would it be equivalent to smoking for a lifetime, or could my lungs still be unharmed? I have never smoked in my life :). Thank you for the advice, preferably from an anesthetist. Best regards.
Hello,
Sometimes ventilation with 100% oxygen
Harmful only with long-term use (days and weeks) is almost always done at the beginning of full anesthesia, and often during the emergence, and of course in emergencies with acute breathing problems.
You don't have to worry about that.
It is true that "oxidative stress" is caused by free radicals.
A very dangerous or fixed connection with lung cancer is not yet proven to my knowledge. However, due to these new findings, a new focus on safety is emerging in both intensive care and emergency medicine, namely to only use 100% oxygen concentrations if there is a medical benefit, or in emergency situations. The old saying that oxygen is always right is no longer true. In particular, an uncritical long-term use of 100% oxygen is no longer carried out. Initially, attempts are made to achieve the goal with lower concentrations.
This is not comparable to cigarette smoking at all. As you have already correctly recognized, the increased oxygen concentration is only of very short duration. With the end of oxygen supply, the levels drop back to physiological values within minutes. Condensate, tar, carcinogens, and last but not least, radioactive particles from tobacco, remain in the lung tissue in the long term and continue their harmful effects. The alpha emitter alone emits over 120 J (half-life). Therefore, a bronchial carcinoma triggered by cigarette consumption can still develop years after smoking cessation.
If you are still unsure, have a lung function test carried out by your general practitioner or specialist. It is quick and I think you will measure completely normal values there.
With best regards, Dr. R. Berg
