The effect of positive airway pressure during pre-oxygenation and induction of anaesthesia upon duration of non-hypoxic apnoea.
Positive end-expiratory pressure (PEEP) applied during induction of anaesthesia may prevent atelectasis formation in the lungs. This may increase the duration of non-hypoxic apnoea by increasing the functional residual capacity. We studied the benefit of PEEP applied during the induction of anaesthesia on the duration of apnoea until the SpO2 reached 90%. Forty ASA I-II patients were randomly allocated to one of two groups. In the PEEP group (n = 20) patients were pre-oxygenated using 100% O2 administered using a CPAP device (6 cmH2O) for 5 min. Following induction of anaesthesia, patients were mechanically ventilated (PEEP 6 cm H2O) for a further 5 min. In the ZEEP group (n = 20), no CPAP or PEEP was used. The duration of apnoea until SpO2 reached 90% was measured. Non-hypoxic apnoea duration was longer in the PEEP group compared to ZEEP group (599 +/- 135 s vs. 470 +/- 150 s, p = 0.007). We conclude that the application of positive airway pressure during induction of anaesthesia in adults prolongs the non-hypoxic apnoea duration by > 2 min.
Herriger
A
A
Departments of Anaesthesiology, University Hospital, CHUV BH-100, 1011 Lausanne, Switzerland.
Frascarolo
Ph
P
Spahn
D R
DR
Magnusson
L
L
D000293:Adolescent; D000328:Adult; D000768:Anesthesia, General / Q000009:adverse effects*; D002245:Carbon Dioxide / Q000097:blood; D005260:Female; D006801:Humans; D007431:Intraoperative Complications / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood*; D010102:Oxygen Inhalation Therapy; D010313:Partial Pressure; D011175:Positive-Pressure Respiration; D001261:Pulmonary Atelectasis / Q000209:etiology / Q000517:prevention & control*; D013997:Time Factors
D002245:Carbon Dioxide; D010100:Oxygen