Background
Catecholamines, mainly dobutamine, are often administered without institutional guidelines or prespecified algorithms in cardiac surgery. The current study assessed the consequences on clinical outcome of catecholamines simply based on the clinical judgment of the anesthesiologists after cardiopulmonary bypass in adult cardiac surgery.
Methods
Consecutive patients were enrolled in a nonrandomized cohort study. Factors associated with perioperative use of catecholamines and with outcomes were recorded prospectively to conduct bias adjustment, including propensity scores. Major cardiac morbidity (i.e., ventricular arrhythmia, use of an intraaortic balloon pump and postoperative myocardial infarction) and all-cause intrahospital mortality were the primary and secondary endpoints, respectively. Results are expressed as odds ratio (OR) [95% confidence interval].
Results
During the study, 84 of 657 patients (13%) received catecholamines, most often dobutamine (76 of 84, 90%). A higher incidence of both major cardiac morbidity (30 vs. 9%; P < 0.001; OR, 4.2 [2.5-7.3]) and all-cause intrahospital mortality (8 vs. 1%; P < 0.001; OR, 12.9 [3.7-45.2]) was observed in the catecholamine group compared with the control group. After adjusting for channeling bias and confounding factors, catecholamine administration remained significantly associated with major cardiac morbidity after propensity score stratification (OR, 2.1 [1.0-4.4]; P < 0.05), propensity score covariance analysis (OR, 2.3 [1.0-5.0]; P < 0.05), marginal structural models (OR, 1.8 [1.3-2.5]; P < 0.001), and propensity score matching (OR, 3.0 [1.2-7.3]; P < 0.02), but not with all-cause intrahospital mortality.
Conclusions
These results suggest that dobutamine should only be administered when the benefit is judged to outweigh the risks.
Propensity score adjustment using machine learning classification algorithms to control selection bias in online surveys
