Alpard S K, Zwischenberger J B, Tao W, Deyo D J, Traber D L, Bidani A
Department of Surgery, University of Texas Medical Branch and Shriners Burns Institute, Galveston, USA.
Crit Care Med. 2000 May;28(5):1469-76. doi: 10.1097/00003246-200005000-00036.
To develop a predictable, dose-dependent, clinically relevant model of severe respiratory failure associated with a 40% total body surface area, full-thickness (third-degree) cutaneous flame burn and smoke inhalation injury in adult sheep.
Model development.
Research laboratory.
Adult female sheep (n = 22).
Animals were divided into three groups, determined by the number of smoke breaths administered (24, 36, 48) for a graded inhalation injury. The smoke was insufflated into a tracheostomy with a modified bee smoker at airway temperatures <40 degrees C. All animals concurrently received a 40% total body surface area (third-degree) cutaneous flame burn to the body (flanks). After injury, the animals were placed on volume-controlled ventilation to achieve PaO2 >60 mm Hg and PaCO2 <40 mm Hg. Arterial blood gases and ventilator settings were monitored every 6 hrs postinjury for up to 7 days.
All animals survived the induction of injury. In the 24 smoke breath/40% total body surface area burn (24/40) group, PaO2/F(IO2) never decreased below 300, and peak inspiratory pressure was consistently <14 cm H2O with normal arterial blood gases throughout the observation period. With 36 smoke breaths/40% total body surface area burn (36/40) (n = 7), all animals had PaO2/F(IO2) of <200 and peak inspiratory pressure of 26 cm H2O within 40-48 hrs, as 30% died during the study period. With 48 smoke breaths/40% total body surface area burn (48/40) (n = 12), all animals developed respiratory distress syndrome (RDS) in 24-30 hrs, but none survived the experimental period.
Development of RDS by smoke and cutaneous flame bum injury depends on smoke inhalation dose. A combination of 36 breaths of smoke and a 40% total body surface area (third-degree) cutaneous flame burn injury can induce severe RDS (PaO2/F(IO2) <200) within 40-48 hrs to allow evaluation of various treatment modalities of RDS.
建立一种可预测的、剂量依赖性的、与成年绵羊40%体表面积全层（三度）皮肤火焰烧伤及烟雾吸入性损伤相关的严重呼吸衰竭临床相关模型。
模型建立。
研究实验室。
成年雌性绵羊（n = 22）。
根据给予的烟雾呼吸次数（24次、36次、48次）将动物分为三组，以造成分级吸入性损伤。使用改良的蜂用烟熏器在气道温度<40摄氏度时将烟雾吹入气管造口。所有动物同时接受40%体表面积（三度）的身体（侧腹）皮肤火焰烧伤。受伤后，将动物置于容量控制通气下，使动脉血氧分压（PaO2）>60 mmHg且动脉血二氧化碳分压（PaCO2）<40 mmHg。受伤后每6小时监测动脉血气和呼吸机设置，持续7天。
所有动物在损伤诱导后均存活。在24次烟雾呼吸/40%体表面积烧伤（24/40）组中，在整个观察期内，PaO2/吸入氧分数（F(IO2)）从未降至300以下，吸气峰压始终<14 cmH2O，动脉血气正常。在36次烟雾呼吸/40%体表面积烧伤（36/40）组（n = 7）中，所有动物在40 - 48小时内PaO2/F(IO2)<200，吸气峰压为26 cmH2O，在研究期间有30%死亡。在48次烟雾呼吸/40%体表面积烧伤（48/40）组（n = 12）中，所有动物在24 - 30小时内发生呼吸窘迫综合征（RDS），但在实验期内均无存活。
烟雾和皮肤火焰烧伤损伤导致RDS的发生取决于烟雾吸入剂量。36次烟雾呼吸与40%体表面积（三度）皮肤火焰烧伤相结合的损伤可在40 - 48小时内诱发严重RDS（PaO2/F(IO2)<200），以便评估RDS的各种治疗方式。
