2009 OPEN FORUM Abstracts
SHOULD THE FISHER PYKEL RT 236 INFANT CIRCUIT BE RE-TESTED AFTER HEATING UP TO COMPENSATE FOR POSSIBLE CHANGES IN TUBING COMPLIANCE?
Matt McNally; Respiratorry Care, Dartmouth Hitchcock Medical Center, Lebanon, NH
Background: When using the Servo I mechanical ventilator (Maquet Solna Sweeden) there are two options in measuring Tidal Volumes (VT) in the infant mode, proximal to the airway and calculated based on the circuit compliance factor. Our question was when using the internal method, does using a heated circuit over time change the compliance factor and, if it does, when would be the best time to retest the circuit? Methods: We tested the Fisher and Pykel RT 236 circuit (Auckland, New Zealand) on the Servo I mechanical ventilator and recorded the compliance factor at one hour, twelve hours, twenty four hours and twenty eight day intervals. We used twenty eight days because that is the time that we change our ventilator circuits at our institution. Results: The initial compliance factors were calculated between 0.99 ml/cmH2O and 1.01 ml/cmH2O. After one hour the factor increased to 1.05 ml/cmH2O and remained at 1.05 ml/cmH2o (+/- 0.01ml/cmH2O)consistantly until day twenty eight. Conclusions: Based on our findings, we would recommend retesting the circuit one hour after the circuit has been warmed since the compliance factor does not change significantly and not after that. Although 0.04 to 0.06 ml/cmH2O seems small, in relation to the VT of an <1000 gram infant can account for one third of their VT if not corrected. Sponsored Research - None