Chan Kai M, Ng Yu C, So Hing Y
Department of Anesthesia and Intensive Care, The Chinese University of Hong Kong, Shatin, Hong Kong.
Department of ICU, Alice Ho Miu Ling Nethersole Hospital, Hong Kong.
Indian J Crit Care Med. 2020 Nov;24(11):1128-1131. doi: 10.5005/jp-journals-10071-23666.
Patient-ventilator dyssynchrony is commonly due to patient pathophysiologic factors and imprecise ventilator settings. In unusual circumstances, such dyssynchrony can also be due to faults within the equipment preventing from its normal operation during assisted mechanical ventilation.
We report a patient showing an unusual pattern of dyssynchronous breathing related to a blocked scavenging system caused by the failure of its rod valve to open. Collection of water condensate inside its reservoir bag leading to a weight drag and deformation of its shape was found to be the cause. Specifically, our patient manifested as failure to trigger with the development of high positive end-expiratory pressure (PEEP) and paradoxical pressure changes during pressure support ventilation.
Water condensation distal to the ventilator exhaust gas outlet may not be immediately apparent. Clinicians should remain alert with patient-ventilator dyssynchrony, especially with an unusual pattern, as it may signify equipment faults, such as expiratory gas flow obstruction within the scavenging system.
Chan KM, Ng YC, So HY. An Unusual Pattern of Dyssynchronous Breathing due to Expiratory Flow Obstruction in the Scavenging System Caused by the Weight of Water Condensate. Indian J Crit Care Med 2020;24(11):1128-1131.
患者与呼吸机不同步通常是由于患者的病理生理因素和呼吸机设置不准确所致。在特殊情况下，这种不同步也可能是由于设备故障，导致在机械辅助通气期间无法正常运行。
我们报告了一名患者，其出现了一种不寻常的呼吸不同步模式，原因是清除系统的杆状阀未能打开导致堵塞。发现积水收集袋内积水导致重量拖拽并使其形状变形是原因所在。具体而言，我们的患者表现为在压力支持通气期间无法触发，出现高呼气末正压（PEEP）以及矛盾的压力变化。
呼吸机废气出口远端的积水可能不会立即显现。临床医生应警惕患者与呼吸机的不同步情况，尤其是出现不寻常模式时，因为这可能意味着设备故障，例如清除系统内的呼气气流受阻。
Chan KM, Ng YC, So HY. 因积水重量导致清除系统呼气气流受阻引起的不寻常呼吸不同步模式。《印度危重症医学杂志》2020;24(11):1128 - 1131。
