Parkhouse Duncan A, Brown Roger F, Jugg Bronwen J, Harban Fraser M, Platt Jan, Kenward Christopher E, Jenner John, Rice Paul, Smith Adam J
Biomedical Sciences Department, Defence Science and Technology Laboratory, Porton Down, Salisbury, SP4 OJQ, UK.
Mil Med. 2007 Mar;172(3):295-300. doi: 10.7205/milmed.172.3.295.
Phosgene is a chemical widely used in the plastics industry and has been used in warfare. It produces a life-threatening pulmonary edema within hours of exposure, to which no specific antidote exists. This study aims to examine the pathophysiological changes seen with low tidal volume ventilation (protective ventilation (PV)) strategies compared to conventional ventilation (CV), in a model of phosgene-induced acute lung injury. Anesthetized pigs were instrumented and exposed to phosgene (concentration x time (Ct), 2,350 mg x min x m(-3)) and then ventilated with intermittent positive pressure ventilation (tidal volume (TV) = 10 ml x kg(-1); positive end expiratory pressure, 3 cm H2O; frequency, 20 breaths x min(-1); fractional concentration of inspired oxygen, 0.24), monitored for 6 hours after exposure, and then randomized into treatment groups: CV, PV (A) or (B) (TV, 8 or 6 ml x kg(-1); positive end expiratory pressure, 8 cm H2O; frequency, 20 or 25 breaths x min(-1); fractional concentration of inspired oxygen, 0.4). Pathophysiological parameters were measured for up to 24 hours. The results show that PV resulted in improved oxygenation, decreased shunt fraction, and mortality, with all animals surviving to 24 hours compared to only three of the CV animals. Microscopy confirmed reduced hemorrhage, neutrophilic infiltration, and intra-alveolar edema.
光气是一种广泛应用于塑料工业且曾用于战争的化学物质。它在接触数小时内会引发危及生命的肺水肿，目前尚无特效解毒剂。本研究旨在探讨在光气诱导的急性肺损伤模型中，与传统通气（CV）相比，低潮气量通气（保护性通气（PV））策略所观察到的病理生理变化。对麻醉后的猪进行仪器植入，使其接触光气（浓度×时间（Ct），2350毫克·分钟·立方米⁻³），然后采用间歇正压通气（潮气量（TV）=10毫升·千克⁻¹；呼气末正压，3厘米水柱；频率，20次呼吸·分钟⁻¹；吸入氧分数，0.24）进行通气，接触后监测6小时，随后随机分为治疗组：CV、PV（A）或（B）（TV，8或6毫升·千克⁻¹；呼气末正压，8厘米水柱；频率，20或25次呼吸·分钟⁻¹；吸入氧分数，0.4）。测量病理生理参数长达24小时。结果表明，PV导致氧合改善、分流分数降低和死亡率降低，所有采用PV的动物存活至24小时，而CV组动物只有三只存活。显微镜检查证实出血、中性粒细胞浸润和肺泡内水肿减少。
