Impact of paravertebral blocks on analgesic and non-analgesic outcomes after video-assisted thoracoscopic surgery: A propensity matched cohort study.

ABSTRACT

BACKGROUND: Regional analgesic techniques such as paravertebral blocks (PVBs) have been popularized for analgesia following video-assisted thoracoscopic surgery (VATS). In this single center retrospective propensity matched cohort of subjects, we investigate the impact of paravertebral blocks on the analgesic and non-analgesic outcomes. METHODS: Institutional database was queried to identify all patients undergoing VATS between January 2013 and July 2019 and these patients were divided into those who received paravertebral blocks in combination with general anesthesia (GA) [PVB group] and those who received GA without paravertebral blocks [GA group]. Propensity score matching based on common patient confounders were used to identify patients in each group. Primary outcomes of the study were average pain scores and opioid consumption in the first 24 hours. Secondary analgesic outcomes included pain scores and opioid requirements at other timepoints over the first 48 hours. Non analgesic outcomes were obtained from STS General Thoracic Surgery Database and included length of hospital stay, need for ICU admission, composite outcome of any complication during the hospital course and 30-day mortality. Exploratory analyses were conducted to investigate the impact of PVB on analgesia following different types of surgery and as to whether any other covariates had a greater influence on the included patient centered outcomes. MAIN RESULTS: After propensity score matching, a total of 520 patients (260 per group) were selected for the study out of 1095 patients. The opioid consumption in terms of oral morphine milligram equivalent (MME) [Median (IQR)] for the first 24 hours was significantly lower with the use of PVB [PVB group- 78.5 (96.75); GA group-127.0 (111.5); p<0.001] while the average pain scores in the first 24 hours did not differ significantly [PVB group-4.71 (2.28); GA group-4.85 (2.30); p = 0.70]. The length of hospital stay, opioid requirements at other timepoints, need for ICU admission in the immediate post-operative period and the composite outcome-'any complication' (35% vs 48%) were significantly lower with the use of PVB. Subgroup analysis showed a longer duration of benefit following major lung surgeries compared to others. CONCLUSION: Paravertebral blocks reduced the length of stay and opioid consumption up to 48 hours after VATS without significantly impacting pain scores.