Taenzer Andreas H, Kovatsis Pete G, Raessler Kenneth L
Department of Anesthesiology, Maine Medical Center, 22 Bramhall Street, Portland, ME 04102, USA.
Anesth Analg. 2002 Jul;95(1):148-50, table of contents. doi: 10.1097/00000539-200207000-00026.
Anesthesiologists often administer care outside the operating room. These locations may depend on gas cylinders for their oxygen source more than the operating suites supplied by dedicated central pipelines. Using full E-cylinders, we determined the oxygen consumption of two often used, pneumatically driven anesthesia ventilators to answer three questions: How much time is available when mechanically ventilating patients in the setting of absent or malfunctioning central oxygen pipeline? How much oxygen is used by the ventilator to drive the bellows? How does changing the inspiratory to expiratory ratio and the inspiratory flow (Narkomed ventilator only) influence oxygen use? At a ventilation of 5 L/min, we found that mechanical ventilation consumes between 59% and 85% of the available oxygen in an E-cylinder to drive the ventilator at fresh gas flows ranging from 1 to 10 L/min. The time span until the low oxygen alarm sounded ranged from 38 to 99 min. Alteration of the inspiratory flow but not the inspiratory to expiratory ratio had a significant impact. Clinicians must recognize that mechanical ventilation using E-cylinders rapidly depletes this sole oxygen source and could jeopardize patient safety. Conversely, manual or spontaneous ventilation with low fresh gas flows minimizes oxygen depletion.
The time available to ventilate patients with an E-cylinder tank as the sole oxygen source was found to be as short as 38 min. Clinicians must recognize that mechanical ventilation using oxygen cylinders rapidly depletes oxygen and could jeopardize patient safety.
麻醉医生经常在手术室以外的地方实施护理。这些场所可能比由专用中央管道供气的手术室更依赖气瓶作为氧气来源。我们使用满的E型气瓶，测定了两种常用的气动麻醉呼吸机的耗氧量，以回答三个问题：在中央氧气管道缺失或出现故障的情况下，机械通气患者时可用的时间有多久？呼吸机驱动风箱消耗多少氧气？改变吸呼比和吸气流量（仅适用于Narkomed呼吸机）如何影响氧气使用？在通气量为5升/分钟时，我们发现，在新鲜气体流量为1至10升/分钟的情况下，机械通气消耗E型气瓶中59%至85%的可用氧气来驱动呼吸机。低氧警报响起前的时间跨度为38至99分钟。吸气流量的改变有显著影响，但吸呼比的改变没有。临床医生必须认识到，使用E型气瓶进行机械通气会迅速耗尽这一唯一的氧气来源，并可能危及患者安全。相反，采用低新鲜气体流量进行手动通气或自主通气可将氧气消耗降至最低。
发现以E型气瓶作为唯一氧气来源为患者通气的可用时间短至38分钟。临床医生必须认识到，使用氧气瓶进行机械通气会迅速耗尽氧气，并可能危及患者安全。
