Significance of changes of difference in percutaneous-arterial blood partial pressure of carbon dioxide in liquid resuscitation of patients with septic shock / 中国中西医结合急救杂志

ABSTRACT

Objective To approach the significance of changes of percutaneous-arterial blood carbon dioxide partial pressure difference [P(tc-a)CO2] in liquid resuscitation of patients with septic shock. Methods One hundred and sixty-eight patients with septic shock admitted and treated in the Department of Intensive Care Unit (ICU) of Quzhou People's Hospital from January 2015 to January 2018 were enrolled, and after early goal-directed therapy (EGDT) for 6 hours, according to central venous oxygen saturation (ScvO2) and lactate clearance (LC), they were divided into ScvO2 and LC achievement group (ScvO2 ≥ 0.7 and LC≥10%), ScvO2 achievement group (ScvO2 ≥ 0.7 and LC < 10%), LC achievement group (ScvO2 < 0.7 and LC≥10%), and un-achievement group (ScvO2 < 0.7 and LC < 10%). The mechanical ventilation time, ICU hospitalization time, 28-day mortality, P(tc-a)CO2 etc. were compared among the four groups; the receiver operating characteristic curve (ROC) was used to evaluate the predictive value of P(tc-a)CO2 for 28-day prognosis in patients with septic shock. Results The trends of mechanical ventilation time, ICU hospitalization time, and 28-day mortality were all ScvO2 and LC achievement group < LC achievement group < ScvO2 achievement group < un-achievement group [the mechanical ventilation times (days) were respectively 6.12±2.59, 8.43±3.24, 11.78±4.12, 13.03±4.75, ICU hospitalization times (days) were 10.31±2.32, 13.85±3.56, 16.41±3.83, 18.52±4.05, and 28-day mortality rates were 28.85% (15/52), 40.91% (18/44), 51.28% (20/39), 69.70% (23/33)] and the differences among the four groups were statistically significant (all P < 0.05). After 6 hours of EGDT, the heart rate (HR), lactate (Lac), and P(tc-a)CO2 were lower than those before fluid resuscitation, but the mean arterial pressure (MAP), central venous pressure (CVP), and ScvO2 were higher than those before fluid resuscitation among four groups. Except CVP, the differences of other indicators compared among the ScvO2 and LC achievement group, ScvO2 achievement group, LC achievement group and un-achievement group were statistically significant (all P < 0.05). After 6 hours of EGDT, HR, Lac, P(tc-a)CO2 in ScvO2 and LC achievement group, ScvO2 achievement group and LC achievement group were significantly lower than those in the un-achievement group [HR (bpm): 89.05±29.43, 98.82±30.21, 94.33±28.64 vs. 112.85±32.74, Lac (mmol/L): 2.97±1.95, 3.87±2.32, 2.69±1.52 vs. 4.17±2.44, P(tc-a)CO2 (mmHg, 1 mmHg = 0133 kPa): 7.18±4.61, 12.61±5.34, 9.71±4.11 vs. 16.56±10.19], MAP and ScvO2 were significantly higher than those of the un-achievement group [MAP (mmHg): 88.05±21.67, 77.33±18.56, 83.11±19.71 vs. 70.32±18.79, ScvO2: 0.76±0.14, 0.75±0.16, 0.67±0.14 vs. 0.63±0.18, all P < 0.05]. The P(tc-a)CO2 of 28 days survivors were significantly lower than that of the deaths among four groups (mmHg: 5.78±2.27 vs. 14.14±3.65, 7.07±2.81 vs. 15.06±4.11, 6.35±2.09 vs. 14.94±4.06, 7.93±3.81 vs. 18.34±4.63, all P < 0.05). When P(tc-a)CO2 > 7.24 mmHg predicted 28-day mortality in ScvO2 and LC achievement group, the sensitivity was 89.29%, specificity was 91.45%, and the area under ROC curve (AUC) was 0.86; when P(tc-a)CO2 > 9.46 mmHg predicted 28-day mortality in LC achievement group, the sensitivity was 88.72%, specificity was 85.83% and AUC was 0.91; when P(tc-a)CO2 >12.05 mmHg predicted 28-day mortality in ScvO2 achievement group, the sensitivity was 82.79%, specificity was 86.90% and AUC was 0.79; when P(tc-a)CO2 > 16.22 mmHg predicted 28-day mortality in un-achievement group, the sensitivity was 73.35%, specificity was 80.68% and AUC was 0.68. Conclusion P(tc-a)CO2 can be used as an indicator to evaluate fluid resuscitation effect and prognosis in patients with septic shock.