Is four vital capacity breath pre-oxygenation technique useful?: A study

Many techniques of pre-oxygenation have been proposed and followed world-wide. 3–5 minutes of tidal volume pre-oxygenation is the most preferred technique of choice for pre-oxygenation. This technique may not be feasible in emergency situations. Hence this study was conducted to evaluate the efficacy and utility of four vital capacity breath pre-oxygenation technique, as its less time consuming.

Fifty American Society of Anesthesiologists grade I and II patients in the age group of 20–40 years were studied under two groups of 25 each. Group I did not receive any pre-oxygenation and group II received pre-oxygenation in the form of four vital capacity breaths in 30 seconds. Rescue breaths with 100% oxygen were administered to all those patients whose oxygen saturation dropped below 75%.

It was observed that after one minute of post induction apnea, patients in group I had a reduction in oxygen saturation to a mean of 79.92±3.328%, in comparison to 87.24±2.368% in group II. It was also observed that vital parameters at the end of 1 min of apnea were close to baseline values in group II. The results were analysed using the "Analysis of Variance" (ANOVA) method.

Pre-oxygenation with four vital capacity breaths does prolong the onset of desaturation and thus can be useful in emergency situations where time is precious.