Before you push that RSI medication and grab your laryngoscope, take a moment and ask yourself, “How well did you pre-oxygenate your patient?” It might be the difference between a smooth intubation and a dangerously hypoxic disaster. Preoxygenation is all about replacing the nitrogen in the lungs with oxygen, creating a crucial buffer that extends the time a patient can tolerate apnea without desaturation.

But here’s the problem: in critically ill patients—those with severe lung disease, shock, or metabolic derangements—standard preoxygenation with a non-rebreather mask often isn’t enough. These patients have high oxygen demands, low functional residual capacity, and shunting that limits gas exchange.

Without more advanced strategies like high-flow nasal oxygen, noninvasive ventilation, or careful recruitment maneuvers, they can desaturate in seconds, leaving a dangerously narrow window for intubation. So, let’s discuss optimizing preoxygenation when seconds count and failure isn’t an option.