title: The effect of positive end-expiratory pressure level on peak expiratory flow during manual hyperinflation.
abstract: Including positive end-expiratory pressure (PEEP) in the manual resuscitation bag (MRB) may render manual hyperinflation (MHI) ineffective as a secretion maneuver technique in mechanically ventilated patients. In this study we aimed to determine the effect of increased PEEP or decreased compliance on peak expiratory flow rate (PEF) during MHI. A blinded, randomized study was performed on a lung simulator by 10 physiotherapists experienced in MHI and intensive care practice. PEEP levels of 0-15 cm H(2)O, compliance levels of 0.05 and 0.02 L/cm H(2)O, and MRB type were randomized. The Mapleson-C MRB generated significantly higher PEF (P < 0.01, d = 2.72) when compared with the Laerdal MRB for all levels of PEEP. In normal compliance (0.05 L/cm H(2)O) there was a significant decrease in PEF (P < 0.01, d = 1.45) for a PEEP more than 10 cm H(2)O in the Mapleson-C circuit. The Laerdal MRB at PEEP levels of more than 10 cm H(2)O did not generate a PEF that is theoretically capable of producing two-phase gas-liquid flow and, consequently, mobilizing pulmonary secretions. If MHI is indicated as a result of mucous plugging, the Mapleson-C MRB may be the most effective method of secretion mobilization.
authors.affiliation: *Alfred Hospital/La Trobe University, Melbourne, †Prince of Wales Hospital, Hong Kong, ‡University of Queensland, Australia.
authors.forename: Camila
authors.initials: C
authors.lastname: Savian
authors.forename: Pamela
authors.initials: P
authors.lastname: Chan
authors.forename: Jennifer
authors.initials: J
authors.lastname: Paratz
mesh_terms: D000328:Adult; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008170:Lung Compliance / Q000502:physiology; D008297:Male; D008953:Models, Anatomic; D010366:Peak Expiratory Flow Rate / Q000502:physiology*; D011175:Positive-Pressure Respiration / Q000295:instrumentation / Q000379:methods*; D012128:Respiratory Distress Syndrome / Q000503:physiopathology