Demetriades D, Chan L S, Bhasin P, Berne T V, Ramicone E, Huicochea F, Velmahos G, Cornwell E E, Belzberg H, Murray J, Asensio J A
Department of Surgery, University of Southern California, Los Angeles 90033, USA.
J Trauma. 1998 Sep;45(3):534-9. doi: 10.1097/00005373-199809000-00020.
Tachycardia is considered a physiologic response to traumatic hypotension. The inability of the heart to respond to shock with tachycardia has been described as paradoxical bradycardia or relative bradycardia. The incidence and clinical significance of this condition in major trauma is not known. The objective of this study was to examine the incidence and prognostic significance of tachycardia and relative bradycardia in patients with traumatic hypotension. Relative bradycardia is defined as a systolic pressure < or = 90 mm Hg and a pulse rate < or = 90 beats per minute.
This is a retrospective study conducted at a large Level I academic trauma center during a 4-year period. Seventeen demographic and injury severity factors were analyzed for their possible role in tachycardic or bradycardic response in hypotensive patients. Incidence and mortality were derived for each subpopulation. Bivariate analysis of the association of incidence and mortality with each risk factor was performed. Factors with p values < 0.2 were included in stepwise logistic regression analyses that identified significant risk factors and derived adjusted relative mortality risks between tachycardic and bradycardic hypotensive patients.
Excluding transfers and patients dead on arrival, 10,833 major trauma patients were seen during the study period. Seven hundred fifty patients (6.9%) had systolic blood pressure < or = 90 mm Hg; 533 patients had tachycardia (overall incidence of 4.9%, or 71.1% of hypotensive patients), and 217 patients had bradycardia (overall incidence of 2.0%, or 28.9% of hypotensive patients). The overall crude mortality was 29.2% among tachycardia patients and 21.7% among bradycardia patients (crude relative risk = 1.34; 95% confidence interval = 1.00-1.81; p = 0.047). The adjusted relative mortality risk between the two groups was 1.23 (95% confidence interval = 0.84-1.73; p = 0.284). Multivariate analysis showed that patients with relative bradycardia in the subgroups with Injury Severity Scores > or = 16, chest Abbreviated Injury Scale scores > or = 3, or abdominal Abbreviated Injury Scale scores > or = 3 had significantly better survival than patients with similar injuries presenting with tachycardia.
Relative bradycardia in hypotensive trauma patients is a common hemodynamic finding. Mortality among tachycardic patients was more predictable than among bradycardic patients using commonly used demographic and injury indicators. The presence of relative bradycardia in some subgroups of patients with severe injuries seems to be associated with better prognosis than the presence of tachycardia.
心动过速被认为是对外伤性低血压的一种生理反应。心脏无法通过心动过速对休克作出反应已被描述为矛盾性心动过缓或相对性心动过缓。这种情况在严重创伤中的发生率和临床意义尚不清楚。本研究的目的是探讨外伤性低血压患者心动过速和相对性心动过缓的发生率及预后意义。相对性心动过缓定义为收缩压≤90mmHg且脉搏率≤90次/分钟。
这是一项在一家大型一级学术创伤中心进行的为期4年的回顾性研究。分析了17个人口统计学和损伤严重程度因素在低血压患者心动过速或心动过缓反应中可能发挥的作用。得出每个亚组的发生率和死亡率。对发生率和死亡率与每个危险因素的关联进行双变量分析。p值<0.2的因素纳入逐步逻辑回归分析，以确定显著危险因素，并得出心动过速和心动过缓低血压患者之间调整后的相对死亡风险。
排除转院患者和入院时死亡的患者，研究期间共诊治10833例严重创伤患者。750例患者（6.9%）收缩压≤90mmHg；533例患者有心动过速（总体发生率为4.9%，占低血压患者的71.1%），217例患者有心动过缓（总体发生率为2.0%，占低血压患者的28.9%）。心动过速患者的总体粗死亡率为29.2%，心动过缓患者为21.7%（粗相对风险=1.34；95%置信区间=1.00 - 1.81；p = 0.047）。两组之间调整后的相对死亡风险为1.23（95%置信区间=0.84 - 1.73；p = 0.284）。多变量分析显示，在损伤严重程度评分≥16、胸部简明损伤量表评分≥3或腹部简明损伤量表评分≥3的亚组中，相对性心动过缓的患者比有类似损伤但表现为心动过速的患者生存率显著更高。
低血压创伤患者的相对性心动过缓是一种常见的血流动力学表现。使用常用的人口统计学和损伤指标，心动过速患者的死亡率比心动过缓患者更具可预测性。在一些重伤患者亚组中，相对性心动过缓的存在似乎比心动过速的存在预后更好。
