title: Evaluation of a simple valve mechanism used to stabilize intraabdominal pressure during surgically induced pneumoperitoneum in small animals.
abstract: BACKGROUND
  Preventing sudden changes in intraabdominal pressure (IAP) during surgical pneumoperitoneum may reduce adverse events. This study aimed to describe a valve system that stabilizes intraabdominal pressure, minimizing complications of erratic fluctuations in IAP.
  
  
  METHODS
  Five male Sprague-Dowley rats were submitted to pneumoperitoneum, with the insufflator set sequentially at 5, 10, and 15 mmHg for each rat. Measures of IAP were taken initially without the valve and then using the same insufflator levels with the valve system regulated to three different pressures (5, 10, and 15 mmHg). The mean of the three highest registered pressures during a 15-min observation was used as the maximal pressure, and the mean of the three lowest registered pressures was used as the minimal pressure for each experimental setting.
  
  
  RESULTS
  Without the valve system, the pressure level set by the insufflator correlated poorly with the actual IAP. When the valve system was used, the IAP pressure was limited by the valve settings regardless of the insufflator settings. Also, the variability of IAP was significantly higher when no valve was used than in all situations that had implementation of the system.
  
  
  CONCLUSIONS
  The valve system was very effective in stabilizing IAP, allowing a reproducible and reliable estimate of IAP and greatly reducing the variability resulting from the cycling mechanism of the insufflator. Due to the small dimensions of intracorporeal cavities in the newborn, this mechanism may help to improve safety when neonatal video-assisted surgery is performed.
authors.affiliation: Department of Surgery, State University of Campinas Medical School, Rua Alexander Fleming, 181, Campinas, SP, 13083-887, Brazil.
authors.forename: Brayner
authors.initials: B
authors.lastname: Iorio
authors.forename: Rogerio F
authors.initials: RF
authors.lastname: de Barros
authors.forename: Márcio L
authors.initials: ML
authors.lastname: Miranda
authors.forename: António Gonçalves
authors.initials: AG
authors.lastname: de Oliveira-Filho
authors.forename: Joaquim M
authors.initials: JM
authors.lastname: Bustorff-Silva
mesh_terms: D000005:Abdomen; D000818:Animals; D002245:Carbon Dioxide / Q000008:administration & dosage; D004867:Equipment Design; D007327:Insufflation / Q000295:instrumentation; D007813:Laparotomy / Q000295:instrumentation*; D008297:Male; D011028:Pneumoperitoneum, Artificial / Q000295:instrumentation*; D011312:Pressure; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D002245:Carbon Dioxide