摘要目的:探讨中心静脉-动脉二氧化碳分压差（GAP）联合GAP与动脉-中心静脉氧含量差比值（GAP比值）在脓毒性休克患者早期预后评估中的价值。方法:选取2018年1月至2022年4月宁波市医疗中心李惠利医院收治的571例脓毒性休克患者进行回顾性分析，根据入院时的GAP和GAP比值分为4组，其中A组（180例）：GAP≤6 mmHg（1 mmHg=0.133kPa）且GAP比值≤1.8，B组（35例）：GAP>6 mmHg且GAP比值≤1.8，C组（113例）：GAP≤6 mmHg且GAP比值>1.8，D组（243例）：GAP>6 mmHg且GAP比值>1.8。根据患者28 d的转归情况分为存活组（339例）和死亡组（232例）。分析各组患者的基本资料、临床和预后指标，采用二元Logistic回归分析影响脓毒性休克患者预后的危险因素，绘制受试者工作特征曲线（ROC）分析GAP联合GAP比值在脓毒性休克早期预后评估中的价值。结果:四组间乳酸、心排量（cardiac output, CO）、血管活性药物评分（vasoactive-inotropic score, VIS）、急性生理与慢性健康评分（APACHE-Ⅱ）、序贯器官衰竭评分(SOFA)、拔管率和28 d病死率差异均有统计学意义（ Z=18.89， F=101.29， Z=131.58， F=24.19， F=24.82， χ2=197.19， χ2=191.58；均 P<0.001）。A组与C组的CO分别为（5.2±1.5）L/min和（4.8±1.5）L/min，均高于D组，差异均有统计学意义（ t=15.87和13.80,均 P<0.001）；D组的VIS、APACHE-Ⅱ、SOFA和28 d病死率分别为20.8（10.9, 33.5）分、（23.8±9.1）分、（13.4±7.0）分和72.0%，均高于其他三组，差异均有统计学意义（ Z=11.76、5.46和5.41； t=8.21、3.70和3.86； t=8.54、3.69和4.46； χ2=191.05、37.38和42.34；均 P<0.05）；D组的拔管率为24.7%，低于其他三组，差异均有统计学意义（ χ2=172.55、47.56和56.92，均 P<0.001）。二元Logistic回归分析显示乳酸、VIS、GAP和GAP比值是患者死亡的独立危险因素，风险比（ OR）值分别为1.14、1.12、1.42和6.51。ROC曲线分析中发现，GAP约登指数为0.53，预测脓毒性休克患者死亡的曲线下面积（AUC）为0.84（95% CI：0.81~0.88），最佳临界值为6.48 mmHg时，敏感性76.3%，特异度76.4%；GAP比值约登指数为0.62，其AUC为0.88（95% CI：0.86~0.91），最佳临界值为2.11时，灵敏度76.3%，特异性85.8%。GAP联合GAP比值的约登指数为0.70，具有良好的预测价值，其AUC为0.94（95% CI：0.92~0.96），灵敏度83.2%，特异性86.7%。 结论:GAP联合GAP比值在脓毒性休克患者早期预后评估中具有良好的临床应用价值。

abstractsObjective:To investigate the early prognostic value of central venous-arterial carbon dioxide tension (GAP) combined with GAP to arterial-central venous oxygen content ratio (GAP ratio) in patients with septic shock.Methods:A total of 571 ICU patients with septic shock in Ningbo Medical Centre Lihuili Hospital from January 2018 to April 2022 were selected as the research objects for the retrospective study. According to the GAP and GAP ratio at the time of admission, patients were divided into four groups: group A (180 cases): GAP ≤6 mmHg (1 mmHg=0.133 kPa) and GAP ratio ≤1.8; group B (35 cases): GAP>6 mmHg and GAP ratio ≤1.8; group C (113 cases): GAP ≤6 mmHg and GAP ratio>1.8; group D (243 cases): GAP>6 mmHg and GAP ratio>1.8. According to 28-day mortality, the patients were divided into survival group (339 cases) and death group (232 cases). The basic data, clinical and prognostic indicators of patients in each group were recorded and analyzed. Binary Logistic regression was used to analyze the risk factors influencing the prognosis of patients with septic shock. The receiver operating characteristic curve (ROC) was drawn to analyze the early prognostic value of GAP and GAP ratio for septic shock.Results:There were significant differences in lactate, cardiac output (CO), vasoactive-inotropic score (VIS), acute physiology and chronic health evaluation (APACHE-Ⅱ), sequential organ failure assessment (SOFA), extubation rate, and 28-day mortality among different groups ( Z=18.89, F=101.29, Z=131.58, F=24.19, F=24.82, χ2=197.19, χ2=191.58, all P<0.001). The levels of CO in group A and group C were (5.2±1.5) L/min and (4.8±1.5) L/min, respectively, which were higher than that in group D with significant differences ( t=15.87 and 13.80, both P<0.001). The VIS, APACHE-Ⅱ, SOFA and 28-day mortality rate in group D were 20.8(10.9, 33.5), (23.8±9.1), (13.4±7.0) and 72.0%, respectively, which were higher than those in the other three groups with significant differences ( Z=11.76, 5.46 and 5.41; t=8.21, 3.70 and 3.86; t=8.54, 3.69 and 4.46; χ2=191.05, 37.38 and 42.34; all P<0.05). The extubation rate in group D was 24.7%, which was lower than those in the other three groups with significant differences ( χ2=172.55, 47.56 and 56.92, all P<0.001). Binary Logistic regression analysis showed that lactate, VIS, GAP, and GAP ratio were independent risk factors for death with OR values of 1.14, 1.12, 1.42 and 6.51, respectively. ROC curve analysis showed that the Youden index of GAP was 0.53, the area under the curve (AUC) for predicting death in patients with septic shock was 0.84(95% CI: 0.81-0.88), and the cut-off value was 6.48 mmHg with the sensitivity of 76.3% and the specificity of 76.4%. The Youden index of GAP ratio was 0.62, the AUC was 0.88(95% CI: 0.86-0.91), and the cut-off value was 2.11 with the sensitivity of 76.3% and the specificity of 85.8%. The Youden index of GAP combined with GAP ratio was 0.70, which had a good predictive value with the AUC of 0.94(95% CI: 0.92-0.96), the sensitivity of 83.2%, and the specificity of 86.7%. Conclusions:GAP combined with GAP ratio has a good clinical application value in the early prognostic evaluation of patients with septic shock.