Okponyia Obiefuna C, McGraw Matthew D, Dysart Marilyn M, Garlick Rhonda B, Rioux Jacqueline S, Murphy Angela L, Roe Gates B, White Carl W, Veress Livia A
Department of Pediatrics, University of Colorado Denver, Aurora, Colorado.
Am J Respir Cell Mol Biol. 2018 Jan;58(1):107-116. doi: 10.1165/rcmb.2016-0223OC.
Chlorine is a highly reactive gas that can cause significant injury when inhaled. Unfortunately, its use as a chemical weapon has increased in recent years. Massive chlorine inhalation can cause death within 4 hours of exposure. Survivors usually require hospitalization after massive exposure. No countermeasures are available for massive chlorine exposure and supportive-care measures lack controlled trials. In this work, adult rats were exposed to chlorine gas (LD) in a whole-body exposure chamber, and given oxygen (0.8 Fi) or air (0.21 Fi) for 6 hours after baseline measurements were obtained. Oxygen saturation, vital signs, respiratory distress and neuromuscular scores, arterial blood gases, and hemodynamic measurements were obtained hourly. Massive chlorine inhalation caused severe acute respiratory failure, hypoxemia, decreased cardiac output, neuromuscular abnormalities (ataxia and hypotonia), and seizures resulting in early death. Oxygen improved survival to 6 hours (87% versus 42%) and prevented observed seizure-related deaths. However, oxygen administration worsened the severity of acute respiratory failure in chlorine-exposed rats compared with controls, with increased respiratory acidosis (pH 6.91 ± 0.04 versus 7.06 ± 0.01 at 2 h) and increased hypercapnia (180.0 ± 19.8 versus 103.2 ± 3.9 mm Hg at 2 h). In addition, oxygen did not improve neuromuscular abnormalities, cardiac output, or respiratory distress associated with chlorine exposure. Massive chlorine inhalation causes severe acute respiratory failure and multiorgan damage. Oxygen administration can improve short-term survival but appears to worsen respiratory failure, with no improvement in cardiac output or neuromuscular dysfunction. Oxygen should be used with caution after massive chlorine inhalation, and the need for early assisted ventilation should be assessed in victims.
氯气是一种高反应性气体，吸入时可造成严重伤害。不幸的是，近年来其作为化学武器的使用有所增加。大量吸入氯气可在接触后4小时内导致死亡。幸存者在大量接触后通常需要住院治疗。对于大量氯气暴露，目前尚无应对措施，且支持性护理措施缺乏对照试验。在本研究中，成年大鼠在全身暴露舱中暴露于氯气（致死剂量），在获得基线测量值后给予氧气（FiO₂ 0.8）或空气（FiO₂ 0.21）6小时。每小时获取氧饱和度、生命体征、呼吸窘迫和神经肌肉评分、动脉血气以及血流动力学测量值。大量吸入氯气导致严重的急性呼吸衰竭、低氧血症、心输出量降低、神经肌肉异常（共济失调和肌张力减退）以及癫痫发作，最终导致早期死亡。氧气可将存活率提高至6小时（87%对42%），并预防观察到的与癫痫发作相关的死亡。然而，与对照组相比，给氯气暴露大鼠给予氧气会加重急性呼吸衰竭的严重程度，呼吸性酸中毒增加（2小时时pH 6.91±0.04对7.06±0.01），高碳酸血症增加（2小时时180.0±19.8对103.2±3.9 mmHg）。此外，氧气并不能改善与氯气暴露相关的神经肌肉异常、心输出量或呼吸窘迫。大量吸入氯气会导致严重的急性呼吸衰竭和多器官损伤。给予氧气可改善短期存活率，但似乎会加重呼吸衰竭，且心输出量或神经肌肉功能障碍并无改善。大量吸入氯气后应谨慎使用氧气，应对受害者早期辅助通气的需求进行评估。
