title: Does sealing endotracheal tube cuff pressure diminish the frequency of postoperative laryngotracheal complaints after nitrous oxide anesthesia?
abstract: OBJECTIVE
  To study endotracheal tube (ETT) cuff pressures during nitrous oxide (N2O) anesthesia when the cuffs are inflated with air to achieve sealing pressure, and to evaluate the frequency of postoperative laryngotracheal complaints.
  
  
  METHODS
  Prospective, randomized, blind study.
  
  
  METHODS
  Metropolitan teaching hospital.
  
  
  METHODS
  50 ASA physical status I and II patients scheduled for elective abdominal surgery.
  
  
  METHODS
  Patients received standard general anesthesia with 66% N2O in oxygen. In 25 patients, the ETT cuff was inflated with air to achieve a sealing pressure (Pseal group). In 25 patients, the ETT cuff was inflated with air to achieve a pressure of 25 cm H2O (P25 group).
  
  
  RESULTS
  ETT intracuff pressures were recorded before (control) and at 30, 60, 90, 120, and 150 minutes during N2O administration. We investigated the frequency and intensity of sore throat, hoarseness, and dysphagia in patients in the Post-Anesthesia Care Unit (PACU) and 24 hours following tracheal extubation. The cuff pressures in the Pseal group were significantly lower than in the P25 group at all time points studied (p < 0.001), with a significant increase with time in both groups (p < 0.001). The cuff pressures exceeded the critical pressure of 30 cm H2O only after 90 minutes in the Pseal group and already by 30 minutes in the P25 group. The frequency and intensity of sore throat, hoarseness, and dysphagia were similar in both groups in the PACU and 24 hours after tracheal extubation (p > 0.05).
  
  
  CONCLUSIONS
  Minimum ETT sealing cuff pressure during N2O anesthesia did not prevent, but instead attenuated, the increase in cuff pressure and did not decrease postoperative laryngotracheal complaints.
authors.affiliation: Department of Anesthesiology of the School of Medicine, UNESP, Botucatu, São Paulo, Brazil. jbraz@fmb.unesp.br
authors.forename: José Reinaldo Cerqueira
authors.initials: JR
authors.lastname: Braz
authors.forename: Alexandre
authors.initials: A
authors.lastname: Volney
authors.forename: Laís Helena Camacho
authors.initials: LH
authors.lastname: Navarro
authors.forename: Leandro Gobbo
authors.initials: LG
authors.lastname: Braz
authors.forename: Giane
authors.initials: G
authors.lastname: Nakamura
mesh_terms: D000328:Adult; D000368:Aged; D000769:Anesthesia, Inhalation; D002675:Child, Preschool; D003680:Deglutition Disorders / Q000517:prevention & control*; D005260:Female; D006685:Hoarseness / Q000517:prevention & control*; D006801:Humans; D007442:Intubation, Intratracheal / Q000009:adverse effects / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009609:Nitrous Oxide / Q000494:pharmacology*; D010612:Pharyngitis / Q000517:prevention & control*; D011183:Postoperative Complications / Q000453:epidemiology / Q000517:prevention & control*; D011312:Pressure; D011446:Prospective Studies
chemical_list: D009609:Nitrous Oxide