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Continuous positive airway pressure/pressure support pre‐oxygenation of morbidly obese patients
Author(s) -
HARBUT P.,
GOZDZIK W.,
STJERNFÄLT E.,
MARSK R.,
HESSELVIK J. F.
Publication year - 2014
Publication title -
acta anaesthesiologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.738
H-Index - 107
eISSN - 1399-6576
pISSN - 0001-5172
DOI - 10.1111/aas.12317
Subject(s) - medicine , anesthesia , oxygenation , continuous positive airway pressure , intubation , arterial blood , blood pressure , tracheal intubation , ventilation (architecture) , obstructive sleep apnea , mechanical engineering , engineering
Background Morbidly obese patients are more prone to desaturation of arterial blood during apnea with induction of anesthesia than are non‐obese. This study aimed to assess the effect of low‐pressure continuous positive airway pressure ( CPAP ) with pressure support ventilation ( PSV ) during pre‐oxygenation on partial oxygen pressure in arterial blood ( PaO 2 ) immediately after tracheal intubation (post‐intubation PaO 2 ). Methods Forty‐four adult patients scheduled for laparoscopic gastric bypass surgery were pre‐oxygenated with 80% O 2 for 2 min, randomized either to CPAP 5 cm H 2 O + PSV 5 cm H 2 O ( CPAP/PSV , n = 22) or neutral‐pressure breathing without CPAP/PSV (control, n = 22). Anesthesia was induced in a rapid‐sequence protocol and the trachea was intubated without prior mask ventilation. Arterial blood gases were measured before pre‐oxygenation, before induction of anesthesia, and immediately following intubation, before the first positive pressure breath. Results After pre‐oxygenation, partial carbondioxide pressure was significantly lower in the CPAP/PSV group (4.9 ± 0.5 k P a), (mean ± standard deviation) than in the control group (5.2 ± 0.7 k P a) ( P = 0.025). Post‐preoxygenation PaO 2 did not differ between the groups, but post‐intubation PaO 2 was significantly higher in the CPAP/PSV group (32.2 ± 4.1 k P a) than in the control group (23.8 ± 8.8 k P a) ( P < 0.001). In the control group, nadir oxygen saturation was lower (median 98%, range 83–99%) than in the CPAP/PSV group (median 99%, range 97–99%, P = 0.011). Conclusions In morbidly obese patients, low‐pressure CPAP combined with low‐pressure PSV during pre‐oxygenation resulted in better oxygenation, compared with neutral‐pressure breathing, and prevented desaturation episodes.