High thoracic epidural analgesia as an adjunct to general anesthesia is associated with better outcome in low-to-moderate risk cardiac surgery patients

Abstract

Objective: The purpose of this study was to evaluate the addition of high thoracic epidural analgesia (HTEA) to general anesthesia in cardiac surgery patients to enhance the fast-track and improvement in outcome.

Design: Retrospective cohort study of prospectively registered data using population-based healthcare databases.

Participants: One thousand seven hundred thirteen consecutive patients scheduled for elective coronary artery bypass grafting, aortic valve replacement, mitral valve surgery, and combinations eligible for supplementation with epidural analgesia. One thousand sixteen patients were matched and analyzed.

Setting: University hospital, single center.

Intervention: To minimize bias and confounding, epidural patients were matched using EuroSCORE criteria to nonepidural in a 1:1 ratio requiring exact match on sex, age, patient factors, cardiac factors, and procedure type together with normal/moderate/poor left ventricular function, insulin-dependent diabetes, and on-pump/off-pump surgery. All together, 1,016 patients (508 each group) were identified with matching criteria.

Measurements and main results: Outcome parameters were 30-day and 6-month mortality, postoperative dialysis, stroke, and myocardial infarction. Univariate analysis showed that epidural analgesia was associated with lower 6-month mortality (p = 0.021), lower frequency of postoperative dialysis (p = 0.029), and lower frequency of myocardial infarction (p = 0.049). No difference was seen in stroke (p = 0.341). However, adjusted odds ratio of selected perioperative variables showed that HTEA only had a positive impact on the frequency of postoperative dialysis (0.22 [0.06-0.74]).

Conclusion: This large, uniquely matched single-center cohort was generated, and, subject to the listed limitations the authors concluded that supplemental HTEA to general anesthesia had a better outcome in low-risk cardiac surgery patients, with a significantly lower 6-month mortality rate compared with the control group. However, regression analysis revealed that HTEA only had an independently positive effect on the frequency of postoperative dialysis.

Keywords: acute kidney injury; cardiac surgery; epidural analgesia; outcome; postoperative dialysis.