Zehtabchi Shahriar, Sinert Richard, Goldman Matthew, Kapitanyan Raffi, Ballas Jerasimos
Department of Emergency Medicine, State University of New York, Downstate Medical Center/Kings County Hospital Center, Brooklyn, NY 11203, USA.
Injury. 2006 Jan;37(1):46-52. doi: 10.1016/j.injury.2005.09.015. Epub 2005 Dec 22.
Determination of occult haemorrhage is an essential part of trauma assessment. We evaluated the diagnostic utility of decreasing haematocrit (DeltaHct) in detecting major injury. Additionally, we tested the correlation between the volume of infused intravenous fluid (IVF) and DeltaHct.
Prospective observational study at a level one trauma centre.
Patients with suspected major injury. exclusion criteria: Patients who received blood transfusion in the first 4 h, and those who deceased or were transferred to other units before the completion of the observation period (4 h). We measured IVF and DeltaHct at 4 h after triage. We classified patients as having minor or major injury on the basis of injury severity score > or =15. Receiver Operating Characteristic (ROC) curve was used to test the diagnostic performance of DeltaHct in identifying major injury. We tested the operating characteristics of DeltaHct cut-off values of 5 and 10 in detecting major injury. We also measured the correlation of IVF and DeltaHct in a subgroup of patients with low potential for blood loss (ISS<3) to account for possibility of haemodilution.
Four hundred and ninety-four patients (convenience sample) were enrolled (age 36+/-17 years, 82% male, 57% blunt trauma). Sixty-three patients (13%) had major injury. The area under the ROC curve for DeltaHct was not significantly different from the unity line (p=0.20). DeltaHct-4 h>5 points had a sensitivity of 40% (95% CI, 29-52%), specificity of 94% (95% CI, 92-96%), likelihood ratio for a positive test (LR+) of 7.1 (95% CI, 4.4-11.7), and likelihood ratio for a negative test (-LR) of 0.64 (95% CI, 0.52-0.78) in identifying major trauma. DeltaHct-4 h>10 points had sensitivity of 16% (95% CI, 9-27%), specificity of 95% (95% CI, 92-0.96%), +LR of 3.0 (95% CI, 1.5-5.9), and -LR of 0.89 (95% CI, 0.80-0.99). In our subgroup analysis, we detected no significant correlation (p=0.09) between the IVF and DeltaHct-4 h.
DeltaHct-4 h>5 or 10 points is suggestive of major injury (high specificity and +LR). However, the failure to drop the Hct cannot be used to rule out major injury (low sensitivity and -LR).
隐匿性出血的测定是创伤评估的重要组成部分。我们评估了血细胞比容降低值（DeltaHct）在检测重大损伤中的诊断效用。此外，我们还测试了静脉输液量（IVF）与DeltaHct之间的相关性。
在一级创伤中心进行前瞻性观察研究。
疑似重大损伤的患者。排除标准：在最初4小时内接受输血的患者，以及在观察期（4小时）结束前死亡或转至其他科室的患者。我们在分诊后4小时测量IVF和DeltaHct。根据损伤严重程度评分≥15将患者分为轻伤或重伤。采用受试者操作特征（ROC）曲线来测试DeltaHct在识别重大损伤中的诊断性能。我们测试了DeltaHct临界值为5和10时在检测重大损伤中的操作特征。我们还在失血可能性低的患者亚组（损伤严重度评分<3）中测量了IVF与DeltaHct的相关性，以考虑血液稀释的可能性。
共纳入494例患者（便利样本）（年龄36±17岁，82%为男性，57%为钝性创伤）。63例患者（13%）有重大损伤。DeltaHct的ROC曲线下面积与单位线无显著差异（p = 0.20）。DeltaHct - 4小时>5个百分点在识别重大创伤时的敏感性为40%（95%置信区间，29 - 52%），特异性为94%（95%置信区间，92 - 96%），阳性试验似然比（LR+）为7.1（95%置信区间，4.4 - 11.7），阴性试验似然比（-LR）为0.64（95%置信区间，0.52 - 0.78）。DeltaHct - 4小时>10个百分点的敏感性为16%（95%置信区间，9 - 27%），特异性为95%（95%置信区间，92 - 96%），+LR为3.0（95%置信区间，1.5 - 5.9），-LR为0.89（95%置信区间，0.80 - 0.99）。在我们的亚组分析中，未检测到IVF与DeltaHct - 4小时之间存在显著相关性（p = 0.09）。
DeltaHct - 4小时>5或10个百分点提示有重大损伤（高特异性和LR+）。然而，血细胞比容未下降不能用于排除重大损伤（低敏感性和-LR）。
