Abstract 14982: Paravertebral Block With a Paravertebral Catheter May Improve Outcomes After Minimally-invasive Cardiac Surgery

Background: Postoperative (post-op) pain following minimally-invasive cardiac surgery (MICS) may complicate outcomes in patients having surgery performed through a right mini-thoracotomy. Regional anaesthesia, by delivery of local anaesthetic agents to the paravertebral space using a paravertebral catheter (paravertebral block, PVB) may be useful to reduce post-op pain, however, few studies have reported outcomes on patients undergoing MICS with the use of a PVB. Methods: Ninety consecutive patients who underwent MICS at Vancouver General Hospital between January 2016 and May 2019 were included in this retrospective study. Data were collected for 53 patients who only had routine pain control (control) and 37 patients who had a PVB (PVB). Primary outcomes were post-op opioid use and hospital length of stay (LOS). Peri-operative (peri-op) death and stroke were secondary outcomes. Statistical analyses were performed using ANOVA single factor and t-tests. Results: Patient demographics and operative times were comparable between the two groups. The average total amount of opioid consumed in the PVB group was lower at 155.3 mg morphine equivalents, compared to 193.9 mg in the control group, however, the difference was not statistically significant (p=0.39) (Figure 1). However, the percentage of patients who did NOT receive any oxycodone was almost double in the PVB group (43.2% vs 24.5%, PVB vs control, respectively. p=0.06). The average LOS for the PVB group was significantly lower than the control group (5.4 vs 8.3 days, PVB vs control, respectively. p=0.006) (Figure 1). There were no peri-op deaths or strokes. Conclusion: In our experience, addition of a regional anesthetic was associated with ~20% reduction in the amount of opioid narcotic required. Although not statistically significant, this may be a clinically important difference, as the LOS was significantly lower in the PVB group. Outcomes in patients undergoing MICS may be improved with the addition of a PVB.