Kaplan Lewis J, Kellum John A
Department of Surgery, Section of Trauma, Critical Care, and Surgical Emergencies, Yale University School of Medicine, New Haven, CT 06520, USA.
Shock. 2008 Jun;29(6):662-6. doi: 10.1097/shk.0b013e3181618946.
This study determines whether mortality after major trauma is predicted by the strong ion gap (SIG) and whether recent refinements in the calculation of SIG improve its predictive value. The design was an observational, retrospective review of trauma patients admitted on a single service at a level 1 facility. The setting was an urban level 1 trauma facility. An unselected cohort of patients sustaining blunt and/or penetrating injury requiring intensive care unit care was chosen. There were no interventions. Age, injury mechanism, survival, arterial blood gases, hemoglobin, albumin, electrolytes, lactate, standard base deficit, strong ion difference (SID), buffer base, and SIG were analyzed. Patients were grouped into survivors and nonsurvivors according to in-hospital survival truncated to 28 days. Multivariate logistic regression was used for further analysis of univariate predictors of mortality, and receiver-operator characteristic curves were generated for mortality. Both nonsurvivors (n = 26) and survivors (n = 52) were similar with respect to age (31.9 +/- 11.5 vs. 33.5 +/- 11.6 years) and injury mechanism (blunt 61% vs. 58%) Nonsurvivors were more likely to have multicavity injury (54% vs. 26%; P < 0.01) than survivors. Nonsurvivor and survivor pH (7.36 +/- 0.15 vs. 7.38 +/- 0.09), HCO3(-) (20.4 +/- 3.9 vs. 21.7 +/- 2.5 mEq/L; P = 0.11), albumin (3.6 +/- 0.7 vs. 3.5 +/- 0.5 gm/dL), lactate (2.9 +/- 2.5 vs. 2.3 +/- 1.3 mmol/L; P = 0.24), and phosphate (3.1 +/- 0.9 vs. 3.4 +/- 0.8 mEq/L; P = 0.26) were similar. Forty-two percent of nonsurvivors had normal lactate levels, whereas 33% of survivors had lactic acidosis. However, the apparent SID (41.0 +/- 4.2 vs. 36.7 +/- 5.5 mEq/L; P < 0.001), effective SID (32.7 +/- 4.2 vs. 35.4 +/- 4.9 mEq/L; P = 0.019), and SIG (8.3 +/- 4.4 vs. 1.3 +/- 3.6 mEq/L; P < 0.001) were all significantly different between nonsurvivors and survivors. Only one (2%) survivor had an SIG greater than 5 mEq/L, and only two (7%) nonsurvivors had an SIG less than 5 mEq/L. Admission pH, HCO3-, and lactate were poor predictors of hospital mortality after trauma. An elevated SIG presaged mortality after injury and should be assessed on admission.
本研究旨在确定重伤后死亡率是否可由强离子间隙（SIG）预测，以及SIG计算方法的近期改进是否能提高其预测价值。研究设计为对一家一级医疗机构单一科室收治的创伤患者进行观察性回顾研究。研究地点为城市一级创伤中心。选取了一组未经筛选的钝性和/或穿透性损伤且需要重症监护的患者。未进行干预措施。分析了患者的年龄、损伤机制、生存情况、动脉血气、血红蛋白、白蛋白、电解质、乳酸、标准碱缺失、强离子差（SID）、缓冲碱和SIG。根据28天内的院内生存情况将患者分为幸存者和非幸存者。采用多因素逻辑回归对死亡率的单因素预测指标进行进一步分析，并绘制死亡率的受试者工作特征曲线。非幸存者（n = 26）和幸存者（n = 52）在年龄（31.9±11.5岁 vs. 33.5±11.6岁）和损伤机制（钝性伤61% vs. 58%）方面相似。非幸存者比幸存者更易发生多腔损伤（54% vs. 26%；P < 0.01）。非幸存者和幸存者的pH值（7.36±0.15 vs. 7.38±0.09）、HCO3-（20.4±3.9 vs. 21.7±2.5 mEq/L；P = 0.11）、白蛋白（3.6±0.7 vs. 3.5±0.5 gm/dL）、乳酸（2.9±2.5 vs. 2.3±1.3 mmol/L；P = 0.24）和磷酸盐（3.1±0.9 vs. 3.4±0.8 mEq/L；P = 0.26）相似。42%的非幸存者乳酸水平正常，而33%的幸存者存在乳酸酸中毒。然而，非幸存者和幸存者的表观SID（41.0±4.2 vs. 36.7±5.5 mEq/L；P < 0.001）、有效SID（32.7±4.2 vs. 35.4±4.9 mEq/L；P = 0.019）和SIG（8.3±4.4 vs. 1.3±3.6 mEq/L；P < 0.001）均存在显著差异。仅有1名（2%）幸存者的SIG大于5 mEq/L，仅有2名（7%）非幸存者的SIG小于5 mEq/L。入院时的pH值、HCO3-和乳酸对创伤后医院死亡率的预测价值较差。SIG升高预示着损伤后的死亡率，应在入院时进行评估。
