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

详细信息    查看全文

• 作者：Zecha-Stallinger ; Angelika ; Wenzel ; Volker ; Wagner-Berger ; Horst G. ; von Goedecke ; Achim ; et. al.
• 关键词：Tidal volume ; Respiration-artificial ; Bag&ndash ; valve ventilation ; Unprotected airway ; Lung ventilation ; Gastric inflation ; Basic life support ; Volume corrente ; Ventilaç ; ã ; o artificial ; Ventilaç ; ã ; o com insuflador manual ; Via a&eac
• 刊名：Resuscitation
• 出版年：2004
• 出版时间：April, 2004
• 年：2004
• 卷：61
• 期：1
• 页码：69-74
• 全文大小：143 K

文摘

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, 1500ml) 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 500ml, compared with a paediatric self-inflating bag (max. volume, 380ml), and a standard adult self-inflating bag (max. volume, 1500ml) 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, 100ml/0.098kPa (100ml/cm H₂O); airway resistance, 0.39kPa/(ls) (4cm H₂O/(ls)), and a valve simulating lower oesophageal sphincter pressure, 1.47kPa (15cm H₂O). Twenty critical care nurses volunteered for the study and ventilated the manikin for 1min with a respiratory rate of 20min⁻¹ with each ventilation device in random order. The mouth-to-bag-resuscitator versus paediatric self-inflating bag resulted in significantly (P<0.05) higher lung tidal volumes (302±41ml versus 233±22ml), and peak airway pressure (10±1cm H₂O versus 9±1cm H₂O), but comparable inspiratory time fraction (28±5 % versus 27±5 % , T_i/T_tot), peak inspiratory flow rate (0.6±0.1l/s versus 0.6±0.2l/s), and stomach inflation (149±495ml/min versus 128±278ml/min). In comparison with the adult self-inflating bag, there was significantly (P<0.05) less gastric inflation (3943±4896ml/min versus 149±495ml/min versus 128±278ml/min, respectively) with both devices, but the standard adult self-inflating bag had significantly higher lung tidal volumes (566±77ml), peak airway pressure (13±1cm H₂O), and peak inspiratory flow rate (0.8±0.11l/s). In conclusion, comparing the mouth-to-bag-resuscitator with small tidal volumes versus the paediatric self-inflating-bag during simulated ventilation of an unintubated patient in respiratory arrest resulted in comparable marginal stomach inflation, but significantly reduced the likelihood of gastric inflation compared to the adult self-inflating-bag. Lung tidal volumes were improved from 250ml with the paediatric self-inflating-bag to 300ml with the mouth-to-bag-resuscitator.