D'Orio V, Mendes P, Carlier P, Fatemi M, Marcelle R
Department of Physiology, State University of Liège, Belgium.
Crit Care Med. 1991 Jul;19(7):955-62. doi: 10.1097/00003246-199107000-00022.
We studied the effect of volume resuscitation on lung fluid balance and systemic oxygen extraction during septic shock in eight anesthetized dogs. Sepsis was induced using a 2-hr continuous infusion of Escherichia coli endotoxin at 0.25 micrograms/min.kg. Relationships between oxygen uptake (VO2) and oxygen supply (DO2) were performed acutely during stepwise controlled decrements in cardiac output by progressive inflation of an intracardiac balloon. At each stage, DO2 and corresponding VO2 were measured independently and the individual critical DO2 level was referred to as the point below which the relationship held. The slope of such a constructed relationship was defined as the maximal oxygen extraction ratio. Lung fluid balance was assessed by measurements of extravascular lung water. All values were studied at baseline, after endotoxin insult, and after reversing hypotension by a 10% dextran infusion.
Endotoxin infusion led to a shock state that associated hypotension (from 135 to 63 mm Hg) with increases in blood lactate (from 0.53 to 3.9 mmol/L). The mean critical DO2 and maximal oxygen extraction ratio were significantly altered from 7.9 to 17.8 mL/min.kg and from 0.81 to 0.38, respectively. After reversing hypotension by 28 mL/kg colloid infusion, the critical DO2 (11.4 mL/min.kg) and maximal oxygen extraction ratio (0.48) were significantly improved. However, restoration of normal values required a state of fluid overload by further dextran infusion (8 mL/kg). At the end of the fluid challenge, extravascular lung water significantly increased from 6.4 to 17.4 mL/kg.
These data suggest that volume loading may reverse endotoxin-induced peripheral perfusion abnormalities. However, substantial pulmonary edema may occur, possibly jeopardizing the beneficial effects of fluid expansion.
我们研究了容量复苏对8只麻醉犬脓毒性休克期间肺液体平衡和全身氧摄取的影响。通过以0.25微克/分钟·千克的速度持续输注大肠杆菌内毒素2小时诱导脓毒症。在通过心内球囊逐渐充气使心输出量逐步控制性降低的过程中，急性测定氧摄取量（VO2）与氧供量（DO2）之间的关系。在每个阶段，独立测量DO2和相应的VO2，个体临界DO2水平被定义为该关系成立的阈值以下的点。这种构建关系的斜率被定义为最大氧摄取率。通过测量血管外肺水评估肺液体平衡。所有数值均在基线、内毒素损伤后以及通过输注10%右旋糖酐纠正低血压后进行研究。
内毒素输注导致休克状态，伴有低血压（从135毫米汞柱降至63毫米汞柱）和血乳酸升高（从0.53毫摩尔/升升至3.9毫摩尔/升）。平均临界DO2和最大氧摄取率分别从7.9毫升/分钟·千克和0.81显著改变为17.8毫升/分钟·千克和0.38。通过输注28毫升/千克胶体纠正低血压后，临界DO2（11.4毫升/分钟·千克）和最大氧摄取率（0.48）显著改善。然而，要恢复到正常值需要通过进一步输注右旋糖酐（8毫升/千克）达到液体超负荷状态。在液体冲击结束时，血管外肺水从6.4毫升/千克显著增加至17.4毫升/千克。
这些数据表明容量负荷可能逆转内毒素诱导的外周灌注异常。然而，可能会发生大量肺水肿，这可能会危及液体扩容的有益效果。
