Effect of positive end-expiratory pressure on gastric insufflation during induction of anaesthesia when using pressure-controlled ventilation via a face mask

Abstract

BACKGROUND Face mask ventilation (FMV) during induction of anaesthesia is associated with risk of gastric insufflation that may lead to gastric regurgitation and pulmonary aspiration. A continuous positive airway pressure (CPAP) has been shown to reduce gastric regurgitation. We therefore hypothesised that CPAP followed by FMV with positive end-expiratory pressure (PEEP) during induction of anaesthesia would reduce the risk of gastric insufflation. OBJECTIVE The primary aim was to compare the incidence of gastric insufflation during FMV with a fixed PEEP level or zero PEEP (ZEEP) after anaesthesia induction. A secondary aim was to investigate the effects of FMV with or without PEEP on upper oesophageal sphincter (UES), oesophageal body and lower oesophageal sphincter (LES) pressures. DESIGN A randomised controlled trial. SETTING Single centre, Department of Anaesthesia and Intensive Care, Örebro University Hospital, Sweden. PARTICIPANTS Thirty healthy volunteers. INTERVENTIONS Pre-oxygenation without or with CPAP 10 cmH 2 O, followed by pressure-controlled FMV with either ZEEP or PEEP 10 cmH 2 O after anaesthesia induction. MAIN OUTCOME MEASURES A combined impedance/manometry catheter was used to detect the presence of gas and to measure oesophageal pressures. The primary outcome measure was the cumulative incidence of gastric insufflation, defined as a sudden anterograde increase in impedance of more than 1 kΩ over the LES. Secondary outcome measures were UES, oesophageal body and LES pressures. RESULTS The cumulative incidence of gastric insufflation related to peak inspiratory pressure (PIP), was significantly higher in the PEEP group compared with the ZEEP group (log-rank test P < 0.01). When PIP reached 30 cmH 2 O, 13 out of 15 in the PEEP group compared with five out of 15 had shown gastric insufflation. There was a significant reduction of oesophageal sphincter pressures within groups comparing pre-oxygenation to after anaesthesia induction, but there were no significant differences in oesophageal sphincter pressures related to the level of PEEP. CONCLUSION Contrary to the primary hypothesis, with increasing PIP the tested PEEP level did not protect against but facilitated gastric insufflation during FMV. This result suggests that PEEP should be used with caution after anaesthesia induction during FMV, whereas CPAP during pre-oxygenation seems to be safe. TRIAL REGISTRATION ClinicalTrials.gov, identifier: NCT02238691.

Gastric insufflation and high‐flow nasal oxygenation in obstetric patients: a reply

“…Using gastric ultrasound to perform serial cross‐sectional areas of the gastric antrum in both the supine and right lateral decubitus positions, preliminary data involving 30 healthy fasted adults found no significant differences in gastric distension or volume of gastric secretions before or after breathing spontaneously via high‐flow nasal oxygen at 70 l.min ‐1 for 30 min . This finding is consistent with a recent study that found no gastric insufflation when pre‐oxygenation was performed with peak inspiratory pressures of up to 15 cmH 2 O . In the second abstract, the effect of pre‐oxygenation techniques on functional residual capacity were compared in 40 patients undergoing bariatric surgery randomly selected to facemask pre‐oxygenation with a PEEP of 7 cmH 2 O vs. high‐flow nasal oxygen at 50 l.min ‐1 which increased to 70 l.min ‐1 during apnoea.…”

Nasal Continuous Positive Airway Pressure as a Preferred Airway Management During IV Sedation of Obese Patients With Obstructive Sleep Apnea Undergoing Functional Luminal Imaging Probe Panometry

“…In addition, the use of nasal CPAP can decrease the incidence of RRCs by increasing the intrapleural pressure, which would in turn increase the duration of constriction of the lower esophageal sphincter [ 10 ]. As the incidence of RRCs is significantly decreased in the nasal CPAP group, the risk of aspiration could be potentially decreased as well [ 11 ]. Therefore, the use of nasal CPAP as preferred airway management for patients with OSA can provide a consistent supply of oxygen to keep the patient’s airway open throughout the FLIP panometry procedure and thereby prevent any pharyngeal airway obstruction that otherwise leads to intraoperative movements secondary to hypercapnia-induced sympathetic activation translating into the decreased quality of the FLIP panometry results.…”

Effects of neuromuscular blocking agents on the clinical performance of i-gel® and surgical condition in elderly patients undergoing hand surgery: a prospective randomized controlled trial

“…In addition, intraoperative patient movement was not observed in any patient in the rocuronium group. As PIP increases, the risk for gastroesophageal insufflation also increases, which may increase the risk for pulmonary aspiration 28 . Although no significant difference was observed in our study, the rate of gastric insufflation was nearly three times less in the rocuronium group than in the control group (10.3% vs. 32.1%, respectively, P = 0.056).…”