A strategy to optimise the performance of the mouth-to-bag resuscitator using small tidal volumes: effects on lung and gastric ventilation in a bench model of an unprotected airway

• Published in: Resuscitation 2004-04, Vol.61 (1), p.69-74
• Main Authors: Zecha-Stallinger, Angelika, Wenzel, Volker, Wagner-Berger, Horst G, von Goedecke, Achim, Lindner, Karl H, Hörmann, Christoph
• Format: Article
• Language: English
• Subjects: Adult; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Bag–valve ventilation; Basic life support; Benchmarking; Biological and medical sciences; Child; Equipment Design; Gastric inflation; Humans; Insufflation; Insuflación gástrica; Insuflação gástrica; Intensive care medicine; Lung ventilation; Medical sciences; Respiración artificial; Respiration; Respiration-artificial; Resuscitation - instrumentation; Resuscitation - methods; Soporte vital básico; Stomach; Suporte Básico de Vida; Tidal Volume; Unprotected airway; Ventilación bolsa-válvula; Ventilación pulmonar; Ventilação artificial; Ventilação com insuflador manual; Ventilação pulmonar; Via aérea não protegida; Vı́a aérea no protegida; Volume corrente; Volumen corriente
• ISSN: 0300-9572; 1873-1570
• DOI: 10.1016/j.resuscitation.2003.12.012

When ventilating an unintubated patient with a standard adult self-inflating bag, high peak inspiratory flow rates may result in high peak airway pressures with subsequent stomach inflation. In a previous study we have tested a newly developed mouth-to-bag-resuscitator (max. volume, 1500 ml) that limits peak inspiratory flow, but the possible advantages were masked by excessive tidal volumes. The mouth-to-bag-resuscitator requires blowing up a balloon inside the self-inflating bag that subsequently displaces air, which then flows into the patient’s airway. Due to this mechanism, gas flow and peak airway pressures are reduced during inspiration when compared with a standard bag–valve–mask-device. In addition, the device allows the rescuer to use two hands instead of one to seal the mask on the patient’s face. The purpose of the present study was to assess the effects of the mouth-to-bag-resuscitator, which was modified to produce a maximum tidal volume of 500 ml, compared with a paediatric self-inflating bag (max. volume, 380 ml), and a standard adult self-inflating bag (max. volume, 1500 ml) in an established bench model simulating an unintubated patient with respiratory arrest. The bench model consisted of a face mask, manikin head, training lung (lung compliance, 100 ml/0.098 kPa (100 ml/cm H 2O); airway resistance, 0.39 kPa/(l s) (4 cm H 2O/(l s)), and a valve simulating lower oesophageal sphincter pressure, 1.47 kPa (15 cm H 2O). Twenty critical care nurses volunteered for the study and ventilated the manikin for 1 min with a respiratory rate of 20 min −1 with each ventilation device in random order. The mouth-to-bag-resuscitator versus paediatric self-inflating bag resulted in significantly ( P