Shoemaker W C, Kram H B, Appel P L
Department of Surgery, King-Drew Medical Center, University of California, Los Angeles.
Crit Care Med. 1990 Jan;18(1 Pt 2):S19-25.
High-risk patients who survived general (noncardiac) surgery were observed to have cardiac index (CI) values averaging 4.5 L/min.m2, oxygen delivery (DO2) greater than 600 ml/min.m2, and oxygen consumption (VO2) 170 ml/min.m2 during the first 2 or three days postoperatively. Patients who subsequently died maintained relatively normal CI, DO2, and VO2 values in this period. Values of other variables in survivors and nonsurvivors were not appreciably different. An index based on these observations correctly predicted outcome in 94% in a subsequent prospective study. Two hypotheses: a) that increased flow and oxygen transport represent compensatory physiologic responses to an earlier tissue oxygen debt, and b) that these survivors' values were appropriate therapeutic goals, were tested in prospective randomized clinical trials. The protocol group attained those therapeutic goals. This resulted in significantly reduced mortality and morbidity. Optimal goals were more easily attained with colloids, red cells, and an inotropic agent, dobutamine. Dobutamine was used because, in a prospective crossover clinical trial with dopamine at various doses, dobutamine produced greater increases in flow and flow-related variables. More importantly, it improved tissue perfusion as reflected by greater increases in VO2 and greater reductions in pulmonary and systemic vascular resistance.
观察发现，接受普通（非心脏）手术且存活的高危患者在术后头两三天的心脏指数（CI）平均为4.5升/分钟·平方米，氧输送（DO2）大于600毫升/分钟·平方米，氧消耗（VO2）为170毫升/分钟·平方米。随后死亡的患者在此期间的CI、DO2和VO2值保持相对正常。存活者和非存活者的其他变量值没有明显差异。基于这些观察结果得出的一个指标在随后的前瞻性研究中对94%的结果做出了正确预测。两个假设：a）流量和氧运输增加代表对早期组织氧债的代偿性生理反应，b）这些存活者的值是合适的治疗目标，在前瞻性随机临床试验中进行了检验。试验组达到了这些治疗目标。这导致死亡率和发病率显著降低。使用胶体、红细胞和一种正性肌力药物多巴酚丁胺更容易实现最佳目标。使用多巴酚丁胺是因为，在一项不同剂量多巴胺的前瞻性交叉临床试验中，多巴酚丁胺使流量及与流量相关的变量有更大增加。更重要的是，它改善了组织灌注，这表现为VO2有更大增加以及肺血管阻力和体循环血管阻力有更大降低。
