title: Low-positive pressure ventilation improves non-hypoxaemic apnoea tolerance during ear, nose and throat pan-endoscopy: A randomised controlled trial.
abstract: It has been suggested that oxygenation using pressure support ventilation (PSV) before general anaesthesia can reduce the duration of non-hypoxaemic apnoea.
  
  
  
  The objective was to determine whether or not pre-oxygenation with PSV increases the duration of non-hypoxaemic apnoea in non-obese patients during pan-endoscopy.
  
  
  
  A randomised, controlled trial.
  
  
  
  Amiens University Hospital, France.
  
  
  
  Fifty patients scheduled for ENT pan-endoscopy with a BMI lower than 35  kg  m(-2).
  
  
  
  Patients scheduled for pan-endoscopy were enrolled to receive either 100% oxygen at neutral pressure (the control group) or 100% oxygen with positive-pressure ventilation (a positive inspiratory pressure of 4  cmH2O and a positive end-expiratory pressure of 4  cmH2O; the PSV group) during spontaneous ventilation with a face mask. The goal of pre-oxygenation was to obtain an end-tidal oxygen concentration of more than 90% prior to induction of anaesthesia.
  
  
  
  The primary efficacy criterion was the duration of non-hypoxaemic apnoea (i.e. before the peripheral capillary oxygen saturation fell to 90%). Secondary outcomes were duration of pre-oxygenation, pre-oxygenation failure and tolerance.
  
  
  
  The mean (interquartile range) duration of non-hypoxaemic apnoea was longer in the PSV group [598 (447 to 717) s] than in the control group [310 (217 to 451) s] (P < 0.001). Oxygenation time was shorter in the PSV group [190 (159 to 225) s] than in the control group [245 (151 to 435) s] (P = 0.037). Pre-oxygenation was unsuccessful (i.e. end-tidal oxygen concentration was < 90%) in 20% of the patients in the control group but none in the PSV group. The intergroup difference in the duration of pan-endoscopy was not significant. Tolerance was good or very good in all patients.
  
  
  
  Our results show that pre-oxygenation with PSV is associated with a longer duration of non-hypoxaemic apnoea and a lower frequency of manual reventilation during ENT pan-endoscopy. CLINICALTRIALS.
  
  
  
  NCT02167334.
authors.affiliation: From the Anaesthesiology and Critical Care Department, Amiens University Hospital, Place Victor Pauchet (OAA, PGG, BDB, EB, HD, EL); INSERM U1088, Jules Verne University of Picardy, Amiens (PGG, HD, EL); Clinique Sainte Isabelle, Route d'Amiens, Abbeville (ED); Centre de Recherche Clinique CHU Amiens (MD); and ENT Surgery Department, Amiens University Hospital, Place Victor Pauchet, Amiens, France (AB, RZ).
authors.forename: Osama
authors.initials: O
authors.lastname: Abou-Arab
authors.forename: Pierre-Grégoire
authors.initials: PG
authors.lastname: Guinot
authors.forename: Evgeny
authors.initials: E
authors.lastname: Dimov
authors.forename: Momar
authors.initials: M
authors.lastname: Diouf
authors.forename: Bruno
authors.initials: B
authors.lastname: de Broca
authors.forename: Aurélie
authors.initials: A
authors.lastname: Biet
authors.forename: Rody
authors.initials: R
authors.lastname: Zaatar
authors.forename: Eugénie
authors.initials: E
authors.lastname: Bernard
authors.forename: Hervé
authors.initials: H
authors.lastname: Dupont
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Lorne
mesh_terms: D000368:Aged; D000768:Anesthesia, General; D001049:Apnea / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*; D005260:Female; D005602:France; D006785:Hospitals, University; D006801:Humans; D000860:Hypoxia / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*; D017214:Laryngeal Masks; D007828:Laryngoscopy / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D013517:Otorhinolaryngologic Surgical Procedures / Q000009:adverse effects / Q000379:methods*; D011175:Positive-Pressure Respiration / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D013997:Time Factors; D016896:Treatment Outcome