2003 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.