title: Stability and Agreement of a Microtransducer and an Air-Filled Balloon Esophageal Catheter in the Monitoring of Esophageal Pressure.
abstract: BACKGROUND
  The use of esophageal catheters with microtransducer promises advantages over traditional catheters with air-filled balloons. However, performance comparisons between these 2 types of catheters are scarce and incomplete.
  
  
  METHODS
  A catheter with a 9.5-cm air-filled balloon at the distal tip and a catheter with a microtransducer mounted within a flexible silicone rubber were tested in vitro and in vivo. In vitro, the response times of both catheters were compared, and the drift of the baseline pressure of the microtransducer catheter was evaluated over a 6-h period. In vivo, 11 healthy volunteers had both catheters inserted, and the drift of the baseline esophageal pressure was measured over a 3-h period. Also, the correlation and agreement of the baseline and changes in the esophageal pressure of both catheters were evaluated.
  
  
  RESULTS
  In vitro, the microtransducer catheter had a response time significantly higher (262 × 114 Hz, P < .01) and a good pressure stability, with a mean baseline pressure drift of 1.4 cm H2O. In vivo, both catheters presented a small and similar baseline esophageal pressure drift (P = 0.08). For measurements of baseline and changes in esophageal pressure, the correlation and agreement between the catheters were poor, with a large bias between them.
  
  
  CONCLUSIONS
  The catheter with the microtransducer had a small baseline pressure drift, similar to the air-filled balloon catheter. The low agreement between the catheters does not allow the microtransducer catheter to be used as a surrogate for the traditional air-filled balloon catheter.
authors.affiliation: Pulmonary Division, Heart Institute (InCor), Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Renan Maloni
authors.initials: RM
authors.lastname: Augusto
authors.affiliation: Pulmonary Division, Heart Institute (InCor), Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
authors.forename: André Luis Pereira
authors.initials: AL
authors.lastname: Albuquerque
authors.affiliation: Pulmonary Division, Heart Institute (InCor), Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Thomas
authors.initials: T
authors.lastname: Jaeger
authors.affiliation: Pulmonary Division, Heart Institute (InCor), Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Carlos Roberto Ribeiro
authors.initials: CR
authors.lastname: de Carvalho
authors.affiliation: Pulmonary Division, Heart Institute (InCor), Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil. pedro.caruso@hc.fm.usp.br.|Intensive Care Unit, AC Camargo Cancer Center, São Paulo, Brazil.
authors.forename: Pedro
authors.initials: P
authors.lastname: Caruso
mesh_terms: D000328:Adult; D057785:Catheters; D004867:Equipment Design; D004947:Esophagus / Q000502:physiology*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008365:Manometry / Q000295:instrumentation*; D008875:Middle Aged; D018670:Monitoring, Ambulatory / Q000295:instrumentation*; D011312:Pressure; D014160:Transducers, Pressure; D055815:Young Adult
keywords: catheterization/methods; esophagus/physiology; humans; manometry/methods; pressure; respiratory muscles/physiology