RESUMO
Background: Difficult airway management remains a critical procedure with life-threatening adverse events. Current guidelines suggest high-flow therapy by nasal cannulae (HFNC) as a preoxygenation device in this setting. However, there is an evidence gap to support this recommendation. Methods: The PREOPTI-DAM study is an open-label, single-centre, randomised controlled phase 3 trial done at Nantes University Hospital, France. Patients were aged 18-90 years with one major or two minor criteria of anticipated difficult airway management, and requiring intubation for scheduled surgery, were eligible. Patients with body mass index >35 kg/m2 were excluded. Patients were randomly allocated (1:1) to receive 4-min preoxygenation by HFNC or facemask. Randomisation was stratified according to the intubation strategy (laryngoscopic versus fiberoptic intubation). The primary outcome was the incidence of oxygen desaturation ≤94% or of bag-mask ventilation during intubation. The primary and safety analyses included the intention to treat population. This trial is registered with ClinicalTrials.gov (NCT03604120) and EudraCT (2018-A00434-51). Findings: From September 4 2018 to March 31 2021, 186 patients were enrolled and randomly assigned. One participant withdrew consent and 185 (99.5%) were included in the primary analysis (HFNC, N = 95; Facemask, N = 90). The incidence of the primary outcome was not significantly different between the HFNC and the facemask groups, respectively 2 (2%) versus 7 (8%); adjusted difference, -5.6 [95% confidence interval (CI), -11.8 to 0.6], P = 0.10. In the HFNC group, 76 patients (80%) versus 53 (59%) in the facemask group, reported good or excellent intubation experiences; adjusted difference 20.5 [95% CI, 8.3-32.8], P = 0.016. Comparing HFNC with facemask, severe complication occurred in 22 (23%) versus 27 (30%) patients (P = 0.29), and moderate complication in 14 (15%) versus 18 (20%) patients (P = 0.35). No death or cardiac arrest occurred during the study. Interpretation: Compared with facemask, HFNC did not significantly reduce the incidence of desaturation ≤94% or bag-mask ventilation during anticipated difficult intubation but the trial was underpowered to rule out a clinically significant benefit. Patient satisfaction was improved with HFNC. Funding: Nantes University Hospital and Fisher & Paykel Healthcare.
RESUMO
INTRODUCTION: Although preoxygenation and airway management respond to precise algorithms, difficult intubation (DI) remains a daily challenge in intensive care units and in the operating rooms because of its frequent complications, including hypoxaemia. To prevent desaturation during DI, high-flow oxygenation by nasal cannula (HFNC) could prove beneficial. Indeed, contrary to standard preoxygenation device, it can be held in place throughout the intubation trying to perform apnoeic oxygenation during DI. Hence, recent guidelines recommend HFNC during DI, but its relevance has never been evaluated in this setting in a large randomised study until now. METHODS AND ANALYSIS: The PREOPTIDAM trial is a prospective, single-centre, randomised, controlled study in Nantes University Hospital. In anticipated DI, we hypothesised that HFNC can decrease the incidence of desaturation ≤94% or face mask ventilation from 16% to 4% compared with standard device. Using a two-sided t-test with a first species risk of 5% and 80% power, a total of 186 patients will be included. Using a computer-generated randomisation, with a 1:1 allocation ratio, patients will be randomised to HFNC or face mask preoxygenation. Randomisation will be stratified on intubation sequence: Rapid sequence intubation or awake fibreoptic intubation. The primary objective is to determine whether HFNC is more efficient than standard oxygenation techniques to prevent desaturation ≤94% or face mask ventilation during DI. Intent-to-treat and per-protocol analysis are planned for the primary outcome. ETHICS AND DISSEMINATION: The study project has been approved by an independent ethics committee. Written informed consent will be obtained before study inclusion. Participant recruitment begins in September 2018. Results will be submitted to international peer-reviewed medical journals. TRIAL REGISTRATION NUMBER: NCT03604120.
