{'fraction_non_alphanumeric': 0.03722504230118443, 'fraction_numerical': 0.031302876480541454, 'mean_word_length': 4.742718446601942, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 1, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
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.