title: A technique to measure the intracuff pressure continuously: an in vivo demonstration of its accuracy.
abstract: OBJECTIVE
  A major concern with the use of cuffed endotracheal tubes (cETT) in children is hyperinflation of the cuff which may compromise tracheal mucosal perfusion. To measure the intracuff pressure (CP), we devised a method using the transducer of an invasive pressure monitoring device. The objective of the study was to test the accuracy and validity of this device for instantaneous and continuous CP monitoring.
  
  
  METHODS
  The study was conducted in 2 phases. In Phase 1 (200 pediatric patients), after inflation of the cuff, the CP was measured using the standard manometer and the transducer simultaneously. In Phase 2 (20 pediatric patients), the transducer was left connected to the pilot balloon of the ETT to obtain a continuous CP reading and the standard manometer was used to measure the CP at 5-min intervals. Statistical analysis included a Bland-Altman comparison and linear regression analysis.
  
  
  RESULTS
  In Phase 1, linear regression analysis demonstrated an R2 value of 0.9956. The bias was 0.30 cmH2O, the precision was 0.75 cmH2O, and the 95% level of agreement (LOA) ranged from -1.16 to 1.77 cmH2O. In Phase 2, the linear regression analysis revealed an R2 value of 0.9846. The bias was 0.28 cmH2O, the precision was 0.7 cmH2O, and the 95% LOA ranged from -1.1 to 1.66 cmH2O.
  
  
  CONCLUSIONS
  Our study demonstrates that when cETTs are used in the pediatric population, the transducer of the invasive pressure monitoring device can be used reliably to measure the CP at the time of inflation and continuously thereafter.
authors.affiliation: Department of Anesthesiology & Pain Medicine, Nationwide Children's Hospital, Columbus, OH, USA; Department of Anesthesiology, the Ohio State University, Columbus, OH, USA.
authors.forename: Senthil G
authors.initials: SG
authors.lastname: Krishna
authors.forename: Archana S
authors.initials: AS
authors.lastname: Ramesh
authors.forename: Kris R
authors.initials: KR
authors.lastname: Jatana
authors.forename: Charles
authors.initials: C
authors.lastname: Elmaraghy
authors.forename: Meredith
authors.initials: M
authors.lastname: Merz
authors.forename: James
authors.initials: J
authors.lastname: Ruda
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Tobias
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004867:Equipment Design; D005260:Female; D006801:Humans; D007223:Infant; D007442:Intubation, Intratracheal / Q000295:instrumentation*; D008297:Male; D008365:Manometry; D008991:Monitoring, Physiologic / Q000295:instrumentation*; D011312:Pressure; D011446:Prospective Studies; D015203:Reproducibility of Results; D014159:Transducers
keywords: Pediatric anesthesia; cuffed endotracheal tube; intracuff pressure