Hall M W, Peevy K J
Crit Care Med. 1983 Jan;11(1):26-9.
We examined the specifications and design of the inspiratory pressure regulating valve of 8 continuous flow, pressure-limited infant ventilators. Two pressure regulating designs are currently available; one placing the primary pressure regulating valve on the inspiratory limb, the other placing it on the expiratory limb. Seven ventilators incorporate the latter design to limit inspiratory pressure and must have a safety pressure-relief valve located on the inspiratory limb to vent pressure in case of circuit occlusion. These pressure-relief valves are generally set by the manufacturer far in excess of pressures normally used for infant ventilation. Alarm systems are often absent or inadequate to warn of high pressure conditions during circuit obstruction. A case report detailing the fatal complication of prolonged excessive airway pressure during circuit occlusion is presented. Improvements in the pressure-relief valve designs currently available are possible, and may be necessary to provide adequate protection from barotrauma. The majority of infant ventilators currently available expose the patient to unnecessary excessive airway pressures in the case of expiratory limb occlusion, and the lack of alarm systems may leave the operator unaware of malfunction.
我们检查了8台连续气流、压力限制型婴儿呼吸机的吸气压力调节阀的规格和设计。目前有两种压力调节设计；一种是将主压力调节阀置于吸气支路上，另一种是将其置于呼气支路上。七台呼吸机采用后一种设计来限制吸气压力，并且必须在吸气支路上设有安全泄压阀，以便在回路堵塞时排出压力。这些泄压阀通常由制造商设定，远远超过婴儿通气通常使用的压力。报警系统常常缺失或不足以在回路阻塞期间对高压状况发出警报。本文呈现了一份详细描述回路阻塞期间长时间气道压力过高导致致命并发症的病例报告。对目前可用的泄压阀设计进行改进是可行的，并且可能有必要提供足够的保护以防止气压伤。目前大多数可用的婴儿呼吸机在呼气支路阻塞的情况下会使患者暴露于不必要的过高气道压力下，并且报警系统的缺失可能会使操作人员未意识到故障。
