Be'eri Eliezer, Owen Simon, Shachar Mark, Barlavie Yaron, Eisenkraft Arik
Respiratory Rehabilitation Department, Alyn Hospital, Jerusalem, Israel.
Versamed Ltd., Tel-Aviv, Israel.
Disaster Mil Med. 2016 Mar 1;2:3. doi: 10.1186/s40696-016-0015-6. eCollection 2016.
Standard-issue Chemical-Biological-Radio-Nuclear (CBRN) gasmasks, as used for protection from non-conventional warfare agents or toxic industrial compounds, cannot be used by ventilated patients, leaving them exposed to toxic agents inhaled via their ventilators. This study was conducted to determine the safety of a CBRN filter added to the patient circuit of a ventilator, as a method for affording inhalational protection to ventilated patients.
A Landrace pig was ventilated sequentially with 3 types of ventilators according to 17 different ventilation protocols, with and without a CBRN filters added in-line to the ventilation tubing for each protocol. For each protocol, physiological parameters, including oxygen saturation, inspired CO, end tidal CO, inspired oxygen, respiratory rate, and pulse rate, as well as airflow parameters including peak inspiratory pressure, positive end expiratory pressure and tidal volume were measured. The impact on the ventilator's trigger/sensitivity function was evaluated in vitro using a Michigan test lung.
On average, the addition of the CBRN filter resulted in a 16 ml (5 %) decrease (range 0-50 ml) in the tidal volume, a 1.7 cm HO (10 %) decrease (range 1-3 cm HO) in the peak inspiratory pressure, and a 0.1 cm HO (3 %) decrease (range 0-1 cm HO) in the positive end expiratory pressure delivered to the animal. Some ventilators compensated for these airflow changes while others did not, depending on the design of the ventilator's pressure/flow sensing mechanism. Significant rebreathing occurred when the filter was positioned directly on the animal's endotracheal tube, but not when positioned on the air outflow port of the ventilator. measurements showed that the addition of the CBRN filter added a mean pressure gradient of 0.45 cm HO to the trigger/sensitivity function of the system.
In-line addition of a CBRN filter to ventilation tubing is a feasible strategy for affording inhalational protection to ventilated patients.
标准发放的用于防护非常规战争制剂或有毒工业化合物的化学-生物-放射性-核（CBRN）防毒面具，通气患者无法使用，这使得他们暴露于通过呼吸机吸入的有毒制剂中。本研究旨在确定在呼吸机患者回路中添加CBRN过滤器作为为通气患者提供吸入防护方法的安全性。
按照17种不同的通气方案，依次使用3种类型的呼吸机对1头长白猪进行通气，每种方案在通气管道中串联添加或不添加CBRN过滤器。对于每种方案，测量生理参数，包括氧饱和度、吸入一氧化碳、呼气末二氧化碳、吸入氧、呼吸频率和脉搏率，以及气流参数，包括吸气峰压、呼气末正压和潮气量。使用密歇根测试肺在体外评估对呼吸机触发/灵敏度功能的影响。
平均而言，添加CBRN过滤器导致潮气量减少16毫升（5%）（范围为0至50毫升），吸气峰压降低1.7厘米水柱（10%）（范围为1至3厘米水柱），输送给动物的呼气末正压降低0.1厘米水柱（3%）（范围为0至1厘米水柱）。一些呼吸机补偿了这些气流变化，而另一些则没有，这取决于呼吸机压力/流量传感机制的设计。当过滤器直接放置在动物气管导管上时会发生明显的重复呼吸，但放置在呼吸机空气流出端口时则不会。测量结果表明，添加CBRN过滤器使系统的触发/灵敏度功能增加了平均0.45厘米水柱的压力梯度。
在通气管道中串联添加CBRN过滤器是为通气患者提供吸入防护的可行策略。
