Department of Surgery, Division of Trauma and Critical Care, Cedars-Sinai Medical Center, Los Angeles, CA 90048, United States.
Injury. 2012 Nov;43(11):1833-7. doi: 10.1016/j.injury.2011.08.014. Epub 2011 Sep 21.
Systemic hypotension is a well documented predictor of increased mortality following traumatic brain injury (TBI). Hypotension is traditionally defined as systolic blood pressure (SBP)<90 mmHg. Recent evidence defines hypotension by a higher SBP in injured (non-TBI) trauma patients. We hypothesize that hypotension threshold requires a higher SBP in isolated moderate to severe TBI.
A retrospective database review of all adults (≥ 15 years) with isolated moderate to severe TBI (head abbreviated injury score (AIS)≥ 3, all other AIS ≤ 3), admitted from five Level I and eight Level II trauma centres (Los Angeles County), between 1998 and 2005. Several fit statistic analyses were performed for each admission SBP from 60 to 180 mmHg to identify the model that most accurately defined hypotension for three age groups: 15-49 years, 50-69 years, and ≥ 70 years. The main outcome variable was mortality, and the optimal definition of hypotension for each group was determined from the best fit model. Adjusted odds ratios (AOR) were then calculated to determine increased odds in mortality for the defined optimal SBP within each age group.
A total of 15,733 patients were analysed. The optimal threshold of hypotension according to the best fit model was SBP of 110 mmHg for patients 15-49 years (AOR 1.98, CI 1.65-2.39, p<0.0001), 100 mmHg for patients 50-69 years (AOR 2.20, CI 1.46-3.31, p=0.0002), and 110 mmHg for patients ≥ 70 years (AOR 1.92, CI 1.35-2.74, p=0.0003).
Patients with isolated moderate to severe TBI should be considered hypotensive for SBP<110 mmHg. Further research should confirm this new definition of hypotension by correlation with indices of perfusion.
系统性低血压是外伤性脑损伤（TBI）后死亡率增加的一个有充分记录的预测指标。低血压传统上被定义为收缩压（SBP）<90mmHg。最近的证据表明，受伤（非 TBI）创伤患者的低血压定义为较高的 SBP。我们假设，在孤立性中度至重度 TBI 中，低血压阈值需要较高的 SBP。
对 1998 年至 2005 年间从五个一级和八个二级创伤中心（洛杉矶县）收治的所有年龄≥15 岁、孤立性中度至重度 TBI（头部简略损伤评分（AIS）≥3，所有其他 AIS≤3）的成人进行回顾性数据库研究。对 60-180mmHg 范围内的每个入院 SBP 进行了几种拟合统计分析，以确定最准确地定义三个年龄组（15-49 岁、50-69 岁和≥70 岁）低血压的模型。主要结局变量是死亡率，并从最佳拟合模型中确定每个组低血压的最佳定义。然后计算调整后的优势比（AOR），以确定每个年龄组内定义的最佳 SBP 与死亡率增加的关系。
共分析了 15733 例患者。根据最佳拟合模型，低血压的最佳阈值为 15-49 岁患者的 SBP 110mmHg（AOR 1.98，CI 1.65-2.39，p<0.0001）、50-69 岁患者的 SBP 100mmHg（AOR 2.20，CI 1.46-3.31，p=0.0002）和≥70 岁患者的 SBP 110mmHg（AOR 1.92，CI 1.35-2.74，p=0.0003）。
孤立性中度至重度 TBI 患者的 SBP<110mmHg 应被视为低血压。进一步的研究应该通过与灌注指数的相关性来证实这种新的低血压定义。
