Perfusion index during endotracheal intubation and extubation: A prospective observational study

Perfusion index (PI) can be detected using a pulse oximeter. Its value decreases in response to noxious stimuli. Here, we investigated its efficacy in detecting hemodynamic responses during endotracheal intubation and extubation.

An approval from the institutional ethics committee was obtained along with a written informed consent from the patients involved in this study. A sample size of 30 was calculated. Reading of PI, heart rate, and blood pressures (systolic, diastolic, and mean arterial) were recorded at pre-intubation, post-intubation, during neuromuscular block reversal, pre-extubation and at extubation. Clinically significant heart rate, blood pressure (systolic, diastolic, and mean) and PI was defined as increase by >10 bpm, rise by ≥15 bpm and a decrease by ≥10%, respectively, from pre-intubation value.

Clinically significant change in PI was seen at all intervals with maximum decrease in PI occurring during neuromuscular block reversal (42.6% at the start and 56.7% at the end of neuromuscular block reversal). A negative correlation was noted between PI and the other non-invasive hemodynamic parameters.

PI decreases on noxious stimuli and correlates negatively with the other non-invasive hemodynamic parameters. Hemodynamic response at neuromuscular block reversal is maximum.