Predictors of arterial desaturation during intubation: a nested case-control study of airway management-part I.

Background: Arterial desaturations experienced during endotracheal intubation (ETI) may lead to poor outcomes. Thus, our primary aim was to identify predictors of arterial desaturation (pulse oximetry <90%) during the peri-intubation period and to assess outcomes of those who developed arterial hypoxemia.

Methods: Adult patients admitted to a medical and/or surgical intensive care unit (ICU) over the time period of January 1st 2013 through December 31st 2014 who required ETI were included. Only the first intubation was captured. Arterial desaturation was defined as pulse oximetry readings of <90% (hypoxemia) in the immediate peri-intubation period. Patients were then grouped in cases (those who developed desaturation) and controls (those who did not develop this complication).

Results: The final cohort included 420 patients. Arterial desaturations occurred in 74 (18%) patients. When adjusting for significant predictors on univariate analysis and known predictors of a difficult airway, only acute respiratory failure (OR 2.38; 95% CI: 1.15-4.93; P=0.02) and provider training level (OR 7.12; 95% CI: 1.65-30.67; P=0.016) remained significant. Higher pulse oximetry readings prior to intubation was found to be protective on multivariate analysis (OR 0.92; 95% CI: 0.89-0.96; P<0.01; per one percent increase).

Conclusions: Patients who were intubated for acute respiratory failure and those who were intubated by junior level trainees had increased odds of experiencing arterial desaturation in the peri-intubation period. Patients experiencing arterial desaturation had lower pulse oximetry readings prior to intubation suggesting a possible delay at intubation.