A retrospective study was conducted, and patientswho received pulseindicator continuous cardiac output (PiCCO) monitoring were enrolled at the department of critical caremedicine of Peking Union Medical College Hospital from January 1, 2016, to September 1, 2021. Patients were divided into two groups the LCOS group [cardiac index (CI) < 33.34 mL·s -1·m -2, 25 cases] and the non-LCOS group (CI ≥ 33.34 mL·s -1·m -2, 125 cases) according to the CI at 6 hours after surgery. The general clinical data and hemodynamicparameters were collected. Correlations between PP/CVP ratio and PiCCO monitoringindicators were performed with Pearson or Spearman correlation test. Receiver operator characteristic curve (ROC curve) analysis was carried out to evaluate the predictive value of the parameters in patients with LCOS after cardiac surgery.
Results:
A total of 150 patients with PiCCO monitoring after cardiac surgery were included. There were no differences in baseline characteristics between the two groups, while PP in the LCOS group was lower than that in the non-LCOS group [mmHg (1 mmHg ≈ 0.133 kPa) 40 (37, 44) vs. 55 (46, 64)], CVP was higher than that in the non-LCOS group [mmHg 12 (11, 14) vs. 10 (8, 12)], and PP/CVP ratio in the LCOS group was lower than that in the non-LCOS group [3.3 (2.9, 3.7) vs. 5.5 (4.6, 6.8)], with significant differences (all P < 0.05). Correlation analysis results showed that PP/CVP ratio was positively correlated with CI, CO, and stroke volume index (SVI), respectively ( rs = 0.660, 0.592, 0.600, all P < 0.001). CI was negatively correlated with PP ( rs = 0.509, P < 0.001) and positively correlated with CVP ( rs = -0.297, P < 0.001). ROC curveanalysis revealed that compared with PP, CVP, SVI and cardiac function index (CFI), PP/CVP ratio was the best predictor of LCOS after cardiac surgery [area under the ROC curve (AUC) was 0.94±0.02, P < 0.001], when the optimum cut-off value was 4.41, the sensitivity was 80.00%, and the specificity was 96.00%.
Conclusion:
PP/CVP ratio was moderately positively correlated with CO after cardiac surgery, and PP/CVP ratio could be used as a prognostic predictor for LCOS after cardiac surgery.