What is the primary purpose of preoxygenation in the RSI process?

The primary purpose of preoxygenation in the rapid sequence intubation (RSI) process is to optimize oxygen levels before intubation. This practice is critical because it helps increase the patient's oxygen reserves, thereby improving the chances of maintaining adequate oxygenation during the intubation process, which can be brief but potentially hazardous.

When a patient is sedated and paralyzed for intubation, there is a risk of hypoxia due to the interruption of spontaneous breathing. By preoxygenating, the clinician ensures that the patient has a reservoir of oxygen that can sustain them during this period when they may not be able to breathe adequately. This is particularly important for patients who may already have compromised respiratory function.

Preoxygenation usually involves administering 100% oxygen for several minutes prior to intubation, which effectively replaces the nitrogen in the lungs with oxygen. This maneuver can significantly extend the time a patient can safely be without adequate ventilation before experiencing desaturation, thereby improving overall patient safety during the RSI process.