重度蒸汽吸入性损伤后组织氧合的变化

The change in tissue oxygenation after severe steam inhalation injury

采用蒸汽吸入造成实验犬急性肺损伤,探讨伤后心输出量(CO)、氧供量(DO_2)、氧耗量(VO_2)、氧摄取率(ERO_2)、动脉和混合静脉血氧分压(PaO_2和PvO_2)、动脉和混合静脉血氧饱和度(SaO_2和SvO_2)、肺泡氧分压(P_AO_2)以及肺泡-动脉氧分压差(P_(A-a)O_2)等变化。结果表明,蒸汽吸入4h内,CO、DO_2、PaO_2、PvO_2、SaO_2、SvO_2、P_AO_2和pH值均显著下降(P<0.01)、P_(A-a)O_2、ERO_2和PaCO_2均显著升高(P<0.01和0.05),VO_2则无显著变化。提示,蒸汽吸入性损伤后2～4h即可出现组织缺氧,其直接原因是组织灌注和供氧不足。

Tissue oxygenation was observed in dogs inflicted with steam inhalation injury in this study. Main findings were as follows: there was significant decrease in cardiac output (CO), oxygen delivery (DO_2), alveolar oxygen partial pressure (P_AO_2), ar- terial oxygen partial pressure (P_aO_2), mixed venous oxygen partial pressure (P_VO_2), ar- terial oxygen saturation (S_aO_2), mixed venous oxygen saturation (S_VO_2), and pH (P<0. 01), and marked increase in P_(A-a)O_2, oxygen extraction ratio (ERO_2), and arterial carbon dioxide partial pressure (P_aCO_2)(P<0.01 and P<0.05). However there was no obvious change in oxygen consumption rate (VO_2) within four hours after inhalation injury. The results indicated that the tissue hypoxia was caused directly by insufficient blood perfu- sion and oxygen supply as well.