Wo C C, Shoemaker W C, Appel P L, Bishop M H, Kram H B, Hardin E
Department of Emergency Medicine, King-Drew Medical Center, Charles R. Drew University of Health and Science, Los Angeles, CA.
Crit Care Med. 1993 Feb;21(2):218-23. doi: 10.1097/00003246-199302000-00012.
To evaluate the reliability of the vital signs to evaluate circulatory stability as reflected by cardiac index.
Descriptive analysis based on data gathered prospectively, using a predetermined protocol.
University-run county hospital, with a large trauma service.
Sixty-one high-risk trauma patients with accidental injury who were studied immediately after admission to the Emergency Department, and subsequently, 163 critically ill postoperative ICU patients.
Standard fluid therapy, usually crystalloids, but occasionally packed red cell transfusions and colloids, as indicated by clinical criteria.
Arterial BP was measured by pressure transducer and arterial catheter; heart rate (HR) was measured by electrocardiograph signal, and cardiac output was measured by thermodilution. In sudden severe hypovolemic hypotension, the mean arterial pressure (MAP) nadir (lowest) roughly correlated (r2 = .25) with flow, but there was poor correlation (r2 = .0001) when all pressure and flow values were evaluated. The pressure and flow values were obtained throughout the course of the hypotensive episodes during the initial resuscitation in ICU patients and during terminal illnesses.
Observations at the time of acute severe hypotensive crises that show rough correlation of MAP and cardiac index should not be extrapolated throughout the entire hypotensive period or to other less extreme clinical situations. The stress response to hypovolemia, with endogenous catecholamines and neural mechanisms, tends to maintain arterial pressure in the face of decreasing flow for a variable period of time. However, when these mechanisms are overwhelmed by prolonged hypovolemia, the pressure decreases precipitously, but not synchronously, with flow. We conclude that blood flow cannot reliably be inferred from arterial pressure and heart rate measurements until extreme hypotension occurs.
评估生命体征用于评估以心脏指数反映的循环稳定性的可靠性。
基于前瞻性收集的数据进行描述性分析，采用预定方案。
设有大型创伤科服务的大学附属县级医院。
61例因意外伤害入院后立即接受研究的高危创伤患者，以及随后的163例术后入住重症监护病房的危重病患者。
根据临床标准进行标准液体治疗，通常为晶体液，但偶尔也会输注浓缩红细胞和胶体液。
通过压力传感器和动脉导管测量动脉血压；通过心电图信号测量心率（HR），并通过热稀释法测量心输出量。在突然发生的严重低血容量性低血压中，平均动脉压（MAP）最低点（最低值）与血流大致相关（r2 = 0.25），但在评估所有压力和血流值时相关性较差（r2 = 0.0001）。在ICU患者初始复苏期间和终末期疾病的低血压发作过程中获取压力和血流值。
在急性严重低血压危机时观察到的MAP与心脏指数之间的大致相关性，不应外推至整个低血压期或其他不太极端的临床情况。面对血流减少，内源性儿茶酚胺和神经机制引起的对低血容量的应激反应往往会在一段时间内维持动脉血压。然而，当这些机制因长时间低血容量而不堪重负时，压力会急剧下降，但与血流不同步。我们得出结论，在极端低血压发生之前，不能从动脉压和心率测量可靠地推断出血流情况。
