2003 OPEN FORUM Abstracts
THE ACCURACY OF PRESSURE RELIEF VALVES AMONG LEADING NEONATAL MANUAL RESUSCITATORS.
Kurt Schroeder BS CRT, Matt Beckett BS RRT, Jon Miller
BS RRT-NPS, Deborah Cullen EdD RRT FAARC Respiratory Therapy Program
Indiana University Indianapolis Indiana, and George McGarrity Engineered
Medical Systems, Indianapolis Indiana.
BACKGROUND: Newborns who succumb to ventilation via manual resuscitators encounter many risks including that of barotrauma due to the increased peak inspiratory pressures. The role of the pressure relief valve is to vent excess pressure away from the patient's airway. The American Standards for Testing Materials (ASTM) established guidelines to help prevent the incidence of barotrauma with the pressure relief standard at 40cmH2O. While many hospitals consider the cost effective approach in purchasing these devices, Respiratory Therapist need to be cognizant of the quality of the product in hand. The purpose of this study was to compare and contrast the accuracy of the pressure relief valves for 4 commonly used neonatal manual resuscitators.
METHOD: The neonatal manual resuscitators (Ventlab Corp., Ambu Spur, Breathtech, and Portex) were tested using the Infant Michigan Test Lung with data collection by PneumoView. Each manual resuscitator was connected to an oxygen gas flow @ 8LPM and then connected to the test lung with a compliance set at 0.01 L/cmH2O. We provided a respiratory rate of 60BPM with an inspiratory flow rate of approximately 30LPM. Consecutive peak inspiratory pressures were measured at 2 second intervals for 1 minute. Each resuscitation device was tested for three trials. Mean pressures for the trials were calculated.
RESULTS: The average peak inspiratory pressures were as follows: Ambu Spur was 39.90 cmH20 exceeding by 0.25% of ASTM guidelines; Ventilab was 44.18 cmH20 exceeding by 10%, Portex was 48.85 cmH20 exceeding by 22%, and Breathtech 44.47 cmH20 exceeding by 11%.
EXPERIENCE: The Ambu Spur was noted to have a more accurate pressure relief valve in accordance with ASTM guidelines. It was also noted that the Ambu Spur did contain a diaphragm patient valve where as the remaining manual ventilators contained duck bill patient valves. Respiratory Therapists are the primary providers of manual ventilation/resuscitation in the neonatal population. Clinicians need to be aware of the characteristics and limitations of the manual resuscitators they use.
CONCLUSION: Clinicians should not rely on the manufactures claim of the accuracy of their pressure relief valves, but need to review published studies or test independently.