1998 OPEN FORUM Abstracts
Delivered Oxygen Concentration and Work of Breathing when Spontaneously Breathing through Disposable Manual Resuscitator Bags.
Mark Rogers, BS, RCP, RRT Randy Scott, BS, RCP, RRT Thomas Malinowski, BS, RCP, RRT. Department of Respiratory Care, Loma Linda University Medical Center, Loma Linda, California
Introduction: The purpose of this bench study was to evaluate delivered oxygen (FDO_{2}) and imposed work of breathing (WOB) during spontaneous breathing in a cohort of disposable manual resuscitator bags (MRB). Methods: We evaluated five infarit, nine pediatric and eight adult MRBs. Oxygen flow into each MRB was set at 15 LPM. Reservoirs were fully extended (when applicable). A dual chamber test lung was modified to simulate spontaneous breathing. A mechanical ventitator powered one side of the test lung simulating spontaneous breathing in the other lung. The test lung compliance was set at 0.1 mL/cmH_{2}O. Age specific parameters were used: Infant: f = 30, Vt = 70mL, Ti = .6 seconds, ETT = 3.5mm; Pediatric: f = 18, Vt = 200mL, Ti = .95 seconds, ETT = 5.0mm; Adult: f = 10, Vt = 600 mL, Ti = 1.4 seconds, ETT = 7.0mm. The FDO_{2}s were allowed to stabilize and were measured at the endotracheal tube connector using a Perkin-Elmer 1100 Medical Gas Analyzer. Work of breathing measurements were taken from a ten breath average and were obtained using the Ventrak 1500 (Novametrics Medical Systems).
Results: (See table) Infant and pediatric MRBs that employed a one-way valve in the exhalation valve yielded a significantly different (p < 0.005, t-test) FDO_{2} and WOB than those MRBs that do not use a one-way valve. In the adult group, only the FDO_{2} was significantly different (p < 0.005, t-test) in those MRBs that employed the one-way valve.
MRB FDO_{2} WOB Valve
(J/L) Type
Vital Signs Baby Blue - .23 .0285 none
Infant
Simms - Infant .34 .0457 none
Life Designs System Pulmanex .75 .0648 none
- Infant
Ambu Spur - Pediatric/Infant .96 .1409 one-way
Nellcor PB DMR2 - Infant .98 .1367 one-way
Vital Signs Pedi Blue (tail .22 .1563 none
reservoir) - Pediatric
Vital Signs Pedi Blue (neck .22 .1581 none
reservoir) - Pediatric
Simms - Pediatric (latex) .57 .2881 none
Hudson RCI Life Saver - .59 .1544 none
Pediatric
Simms - Pediatric .73 .319 none
Life Designs System Pulmanex .84 .3235 none
- Pediatric
Nellcor PB DMR2 - Pediatric .99 .3041 one-way
Kirk Specialty Systems CapnoFlo .99 .4467 one-way
- Pediatric
Ambu Spur - Pediatric/Infant 1.0 .3681 one-way
Hudson RCI Life Saver - Adult .52 .3435 none
Life Designs System Pulmanex - .66 .6949 none
Adult
Respironics BagEasy - Adult .75 .5084 none
Simms - Adult .78 .7146 none
Vital Signs Adult .85 .8749 none
Kirk Specialty Systems CapnoFlo .93 .8543 one-way
- Adult
Ambu Spur - Adult .98 .5878 one-way
Nellcor PB DMR2 - Adult .98 .614 one-way
Conclusion: MRBs with an expiratory one-way valve yield higher FDO_{2}s than MRBs that do not incorporate a one-way valve. Infant and pediatric MRBs with an expiratory valve in general yield a higher WOB than MRBs without an expiratory valve.
The 44th International Respiratory Congress Abstracts-On-Disk®, November 7 - 10, 1998, Atlanta, Georgia.