High flow nasal cannula oxygenation reduces postoperative hypoxaemia in patients undergoing surgery for morbid obesity

High flow nasal cannula oxygenation reduces postoperative hypoxaemia in patients undergoing surgery for morbid obesity

INCLIVA’s Anaesthesia Research Group is leading the study that has shown that early application of high flow oxygen supplementation in the operating room decreases the severity of postoperative pulmonary complications.
The study has been published in the scientific journal Minerva Anestesiol.

This is a randomised controlled trial aimed at reducing the prevalence of postoperative hypoxaemia with early application of nasal cannula high flow oxygen therapy in morbidly obese patients undergoing bariatric surgery in which an intraoperative open pulmonary approach was applied compared to patients receiving standard oxygen therapy.

This study was carried out in the Anesthesiology and Critical Care Unit of the Hospital Clínico Universitario de Valencia, from May to November 2017 (ClinicalTrials.gov NCT03155711). A total of 64 patients with morbid obesity underwent laparoscopic bariatric surgery (32 in each group) were included. All patients received protocolized protective pulmonary ventilation, including alveolar recruitment maneuvers and positive pressure at the end of individualized expiration (PEEP). There was no difference in ventilatory treatment, duration of surgery or ventilation between the groups. All patients were treated similarly during the perioperative period and during extubation and for the next 2 hours, one group received high flow oxygen and the other conventional oxygen therapy group.

As Prof. Javier Belda, co-author of the study, said: «The results obtained allow us to affirm that oxygenation with a high-flow nasal cannula reduces postoperative hypoxemia in patients with morbid obesity, but also, when high-flow treatment is initiated before extubation, the risk of postoperative pulmonary complications is minimized».

According to the authors, this study shows that oxygen therapy administered through a high flow nasal cannula, and initiated before endotracheal extubation, reduces the complications of hypoxemias and postoperative atelectasis in morbidly obese patients undergoing bariatric surgery. Although a higher prevalence of hypoxemia than initially expected was found, no increase in postoperative morbidity and mortality was observed, as published in previous studies. This may be explained by the development of mild complications, which coincide with previous trials comparing different intraoperative ventilation strategies in bariatric surgery.

The study conclusions suggest a new way of optimizing the performance of oxygen therapy with high-flow cannulas and therefore open the door to future research designed to establish new indications for this treatment during the post-surgical period.

Link to paper: Ferrando C; Puig J; Serralta F; Carrizo J; Pozo N; Arocas B; Gutiérrez A; Villar J; Belda FJ; Soro M. High-flow nasal cannula oxygenation reduces postoperative hypoxemia in morbidly obese patients: a randomized controlled trial. Minerva Anestesiol. 2019 Apr 16. doi: 10.23736/S0375-9393.19.13364-0.

Postoperative Pulmonary Complications

Postoperative pulmonary complications are the most common after surgery and often contribute to increased postoperative morbidity and mortality. Several research groups, including ours, have investigated different perioperative strategies focused on protective lung ventilation, with the aim of reducing surgical complications. These include an intraoperative «open lung» (OLA) approach to reverse alveolar collapse by applying a recruitment maneuver, followed by individualized adjustment of positive pressure at the end of «optimal PEEP» expiration. However, even when an intraoperative approach to lung protection is used, the prevalence of pulmonary complications remains high. Postoperative hypoxemia (lack of oxygen) is the most common complication in the immediate postoperative period and is mainly caused by more or less significant collapses of lung tissue (atelectasis).