麻酔導入時の無低酸素性無呼吸時間（PEEPありなし）の比較：無作為化比較試験

Infants are at the highest risk of oxygen desaturation during induction of anesthesia owing to their distinct anatomical and physiological characteristics. Prolongation of non-hypoxic safe apnea time by use of positive end expiratory pressure (PEEP) during induction has been studied extensively in adults. Although few studies have been conducted in infants, they lacked methodological rigor. Hence, we designed a scientifically rigorous study aimed at investigating the effects of application of PEEP during induction of anesthesia on the duration of non-hypoxic apnea time in infants.

Seventy-two infants were induced as per institutional protocol and mechanically ventilated for three minutes with volume-controlled ventilation and set ventilator parameters with PEEP of either 7 cm H₂O or 0 cm H₂O according to the group allocated, followed by endotracheal intubation. The duration of non-hypoxic apnea time, i.e., the duration from cessation of mechanical ventilation to the point when SpO₂ reached 95%, was noted. Inferential statistics were done by using the independent 't' test, Mann Whitney test and Chi square test.

The duration of non-hypoxic apnea time was significantly longer in the PEEP group (n = 33) as compared to the control group (n = 33); 122 s (IQR = 52) vs. 95 s (IQR = 27) (P = 0.001) The duration of non-hypoxic apnea time increased significantly as the age of the infant increased.

Addition of PEEP of 7 cmH₂O is a useful ventilatory strategy in infants to offset undesired changes in the respiratory physiology during induction of anesthesia.