Kornblith Lucy Z, Howard Benjamin, Kunitake Ryan, Redick Brittney, Nelson Mary, Cohen Mitchell Jay, Callcut Rachael
From the Department of Surgery, San Francisco General Hospital and the University of California, San Francisco, San Francisco, California.
J Trauma Acute Care Surg. 2015 Jan;78(1):30-6; discussion 37-8. doi: 10.1097/TA.0000000000000490.
Although obese patients have high thrombosis rates following injury, the role of obesity in coagulation after trauma remains unknown. We hypothesized that body mass index (BMI) is independently associated with increased measures of hypercoagulability longitudinally after injury.
Data were prospectively collected for 377 consecutive highest-level trauma activation patients with a BMI of 18.5 kg/m² or greater. Standard coagulation measures, citrated kaolin and functional fibrinogen thromboelastography, as well as clotting factors were measured at 0 hour to 120 hours. BMI categories were defined as normal weight (18.5-24.99 kg/m²), overweight (25-29.99 kg/m²), and obese (≥30 kg/m²).
The 377 patients were mostly male (81%) and had blunt injury (61%), with a median BMI of 25.8 kg/m². Of the patients, 42% were normal weight (median BMI, 22.5 kg/m²). There were no differences in age, sex, Injury Severity Score (ISS), or base deficit between groups. There were no differences in admission international normalized ratio/partial thromboplastin time or factors II, V, VII, VIII, and X; antithrombin III; or protein C. However, obese patients had higher admission platelet counts (303 × 10⁹/L vs. 269 × 10⁹/L, p = 0.004), lower D-dimer (1.88 μg/mL vs. 4.00 μg/mL, p = 0.004), and a trend toward higher factor IX (134% vs. 119% activity, p = 0.042) compared with normal weight patients. Measured by thromboelastography, clot strength (maximum amplitude) and functional fibrinogen level (FLEV) were also higher on admission for obese patients (maximum amplitude, 65.7 mm vs. 63.4 mm, p = 0.016; FLEV, 407 mg/dL vs. 351 mg/dL, p = 0.008). In multiple linear regression, the relationship of BMI to clot strength, FLEV, and factor IX persisted through 24 hours. Similarly, the relationship of BMI and platelet count persisted through 120 hours (all p < 0.05). In multiple logistic regression, for every 5-kg/m² increase in BMI, there was an 85% increase in odds of thromboembolic complication (odds ratio, 1.85; 95% confidence interval, 1.13-3.08; p = 0.017).
Obese trauma patients are hypercoagulable compared with their similarly injured normal-weight counterparts, which persists longitudinally after injury. The significance of this hypercoagulability requires elucidation for guidance of anticoagulation in this at-risk group.
Prognostic study, level III.
尽管肥胖患者受伤后血栓形成率较高，但肥胖在创伤后凝血过程中的作用仍不清楚。我们推测，体重指数（BMI）与受伤后纵向高凝状态的增加独立相关。
前瞻性收集了377例连续的最高级创伤激活患者的数据，这些患者的BMI为18.5kg/m²或更高。在0小时至120小时测量标准凝血指标、枸橼酸化高岭土和功能性纤维蛋白原血栓弹力图，以及凝血因子。BMI类别定义为正常体重（18.5-24.99kg/m²）、超重（25-29.99kg/m²）和肥胖（≥30kg/m²）。
377例患者大多为男性（81%），有钝性损伤（61%），BMI中位数为25.8kg/m²。其中42%的患者体重正常（BMI中位数为22.5kg/m²）。各组之间在年龄、性别、损伤严重程度评分（ISS）或碱缺失方面无差异。入院时国际标准化比值/部分凝血活酶时间或因子II、V、VII、VIII和X；抗凝血酶III；或蛋白C无差异。然而，与体重正常的患者相比，肥胖患者入院时血小板计数较高（303×10⁹/L对269×10⁹/L，p=0.004），D-二聚体较低（1.88μg/mL对4.00μg/mL，p=0.004），且因子IX有升高趋势（活性为134%对119%，p=0.042）。通过血栓弹力图测量，肥胖患者入院时的血凝块强度（最大振幅）和功能性纤维蛋白原水平（FLEV）也较高（最大振幅，65.7mm对63.4mm，p=0.016；FLEV，407mg/dL对351mg/dL，p=0.008）。在多元线性回归中，BMI与血凝块强度、FLEV和因子IX的关系持续至24小时。同样，BMI与血小板计数的关系持续至120小时（所有p<0.05）。在多元逻辑回归中，BMI每增加5kg/m²，血栓栓塞并发症的几率增加85%（优势比，1.85；95%置信区间，1.13-3.08；p=0.017）。
与体重正常且受伤情况相似的患者相比，肥胖创伤患者具有高凝状态，且受伤后这种状态会纵向持续存在。这种高凝状态的意义需要阐明，以指导对这一高危群体进行抗凝治疗。
预后研究，III级。
