摘要目的 分析经皮二氧化碳分压(PcCO2)与动脉血二氧化碳分压(PaCO2)梯度P(c-a) CO2监测对脓毒症休克早期诊断、治疗及预后的临床意义.方法 前瞻性比较31例早期脓毒症休克患者(治疗组)及20例非休克患者(对照组)入院时、治疗组实施早期目标导向性治疗(EGDT)后P(c-a) CO2与动脉血乳酸(LAC)等的变化.结果 二组患者入院时P(c-a) CO2基线值分别为(21.2±10.1) mmHg与(7.5 ±4.6) mmHg,P=0.000,LAC基线值分别为(4.0±2.4)mmol/L,与(1.6±0.5)mmol/L,P=0.000,ROC曲线下面积分别为0.918(95％ CI:0.843～0.992)和0.840 (95％ CI: 0.719～0.962),P(c-a) CO2＞ 14.0 mmHg和LAC＞2.1 mmol/L诊断早期脓毒症休克的敏感度均为83.9％、特异度均为90.0％.以P(c-a) CO2和LAC基线值预测脓毒症休克28 d死亡,ROC曲线下面积分别为0.739(95％ CI: 0.562-0.917)和0.702(95％ CI:0.514-0.889),P(c-a)CO2 ＞21.5 mmHg和LAC＞ 3.9 mmol/L预测患者死亡的敏感性均为71.4％、特异性均为70.6％.治疗组31例患者6h内全部完成EGDT治疗,17例(54.8％)存活,14例(45.2％)死亡;其中EGDT复苏达标16例(51.6％),未达标15例(48.4％);复苏达标组存活13例(81.3％),未达标组存活4例(26.7％),F =9.314,P=0.004.EGDT后P(c-a) CO2和LAC分别为(18.8±9.4) mmHg和(3.3±2.4) mmol/L,比入院时基线值显著下降,均P=0.000,其ROC曲线下面积分别为0.742 (95％ CI:0.562～0.921)和0.769 (95％ CI:0.593～0.945),P(c-a) CO2＞ 18.3 mmHg和LAC＞ 3.1 mmol/L预测患者28 d死亡的敏感性均为71.4％、特异性分别为71.4％和76.5％.EGDT后达标组P(c-a) CO2及LAC显著低于未达标组,分别为(14.8±7.5)mmHg: (23.6±9.6)mmHg,P=0.012和(2.5±1.5) mmol/L:(4.3±2.9) mmol/L, P=0.038);EGDT后达标组P(c-a) CO2及LAC显著低于入院时基线值,分别由入院时(18.0±8.1) mmHg降至(14.8±7.5) mmHg, P=0.042和(3.2±1.8) mmol/L降至(2.5±1.5) mmol/L, P=0.043;EGDT后未达标组P(c-a) CO2及LAC与基线值无明显变化,分别由入院时(24.6±9.2)mmHg降至(23.6±9.6)mmHg,P=0.238和(4.8 ±2.5) mmol/L降至(4.3±2.9) mmol/L,P=0.629;与未达标组相比,达标组入院时P(c-a) CO2较低,为(18.0±8.1) mmHg:(24.6±9.2) mmHg,P=0.042),LAC为(3.2±1.8) mmol/L: (4.8±2.5)mmol/L,P=0.050.结论 入院时P(c-a) CO2＞14.0mmHg可作为区分早期脓毒症休克与非休克患者的指标;EGDT是救治早期脓毒症休克的有效措施,P(c-a) CO2能预测并反映EGDT疗效;EGDT前P(c-a) CO2＞ 21.5mmHg及EGDT后P(c-a) CO2＞19.3 mmHg均可作为预测脓毒症休克患者28 d死亡指标,这些作用与LAC相似.

abstractsObjective To investigate the significance of monitoring P(c-a)CO2 (the gradients between transcutaneous PCO2 and arterial PCO2) in patients with septic shock.Method 31 patients with early septic shock were enrolled as the study group and 20 patients with stable hemodynamics as the control group from Fab.2013 to Sept.2014 in our Intensive Care Unit (ICU).The patients with septic shock were treated guided by early goal directed therapy (EGDT) within 6 hours since hospitalization.The differences of baseline P(c-a) CO2 levels and other index as arterial lactate (LAC) concentration between two groups and the variations of these indexes after EGDT in the study group were compared respectively.Results The baseline levels of P(c-a)CO2 and LAC in patients with septic shock were significantly higher than in patients of control group: (21.2 ± 10.1) mmHg vs.(7.5 ±4.6), P =0.000, and (4.0±2.4) mmol/ Lvs.(1.6 ± 0.5), P =0.000.The areas under receiver operator characteristic (ROC) curve (AUC) for baselineP(c-a)CO2 and LAC were 0.918 (95％ CI: 0.843-0.992) and 0.840 (95％ CI: 0.719-0.962) respectively.A threshold of 14.0 mmHg for P(c-a)CO2 and 2.1 mmol/L for LAC discriminated patients with septic shock from without shock with the same sensibility of 83.9％ and the same specificity of 90.0％, respectively.With regard to prognosis (Day 28), AUC for baseline P(c-a)CO2 and LAC were 0.739 (95％ CI: 0.562-0.917) and0.702 (95％ CI: 0.514-0.889) respectively.A threshold of 21.5 mmHg for P(c-a) CO2 and 3.9 mmol/L for LAC discriminated survivors from nonsurvivors with the same sensibility of 71.4％ and the same specificity of 70.6％ respectively.31 patients in the study group completed EGDT within 6 hours after the admission, 16 (51.6％) passed EGDT and 13 (81.3％) survived, 15 (48.4％) failed EGDT and 4 (26.7％) survived, and survival rates were significantly different, F =9.314, P =0.004.After EGDT, P(c-a) CO2 (18.8 ± 9.4) mmHg and LAC (3.3 ± 2.4) mmol/Lreduced significantly compared with the baselines, all P =0.000.AUC then for P(c-a) CO2 and LAC were 0.742 (95％ CI: 0.562-0.921) and 0.769 (95％ CI: 0.593-0.945), respectively.A threshold of 18.3 mmHg for P(c-a)CO2 and 3.1 mmol/L for LAC discriminated survivors from nonsurvivors with the same sensibility of 71.4％ and the specificity of 71.4％ and of 76.5％ respectively.P(c-a) CO2 and LAC of patients passed EGDT reduced significantly compared with those failed EGDT: (14.8 ± 7.5) mmHgvs.(23.6±9.6) mmHg (P=0.012)、 (2.5±1.5) mmol/L vs.(4.3±2.9) mmol/L (P=0.038), and so did with their baseline : (14.8±7.5) mmHgvs.(18.0±8.1) mmHg, (P=0.042)、 (2.5±1.5) mmol/Lvs.(3.2±1.8) mmol/L, P=0.043.In patients failed EGDT, P(c-a)CO2 and LAC changed little after EGDT, from (24.6 ± 9.2) to (23.6 ± 9.6) mmHg (P =0.238) and from (4.8 ± 2.5) mmol/L to (4.3 ± 2.9) mmol/L (P =0.629).When baseline levels were compared between patients passed EGDT with those failed EGDT, P(c-a) CO2 was (18.0 ±8.1) mmHg vs.(24.6 ± 9.2) mmHg (P =0.042), LAC was (3.2 ± 1.8) mmol/L vs.(4.8 ± 2.5) mmol/L (P =0.050).Conclusions P(c-a) CO2 ＞ 14.0 mmHg could play a role in recognizing early septic shock.EGDT was an effective therapy for the disease and P(c-a)CO2 level could reflect the efficacy of EGDT.P(c-a)CO2 ＞ 21.5mmHg before EGDT and P(c-a) CO2 ＞ 19.3 mmHg after EGDT both could predict the prognosis of patients with septic shock.All above correlated well with LAC and represented a new efficient technique to assess tissue microperfusion.