Subcutaneous implantable defibrillator (S-ICD) implantation has unique procedural and management challenges when compared with traditional transvenous ICD implantation. Patients frequently require increased opioids to adequately achieve pain control after the procedure because of the greater amount of pain after S-ICD placement compared to transvenous ICD placement. Many patients require additional hospital inpatient days for pain management before they can be discharged with adequate pain control. Thus, it was postulated that the application of unilateral paravertebral block for each of these patients would provide added pain relief and possibly a reduction in opioid requirement in the postoperative period.
MATERIALS AND METHODS
We compared 10 patients who underwent unilateral left-sided paravertebral block at T3-T4 level prior to S-ICD placement to a consecutive cohort of patients who received S-ICD without a nerve block. Left sided paravertebral block was done under ultrasound guidance. Upon introduction of a needle in to the paravertebral space, each patient received 25 mL of 0.5% bupivacaine and 8 mg of dexamethasone (off-label). The blocks were performed by 2 different anesthesiologists based on availability. We evaluated patient demographics, pain intensity, length of stay, and type of analgesics prescribed retrospectively. IRB waiver was obtained. Pain intensity was rated with Numerical Rating Scale (NRS). Statistical analysis was performed using an independent sample t-test and chi-squared test, respectively.
Nine patients underwent nerve block pre-procedure and one post-procedure. The pain levels reported in the PACU, even though clinically decreased, were not statistically significantly different between the two groups immediately post-procedure (average NRS= 4.5 vs. 8.3, p=0.07). There was no specification of the site of the pain immediately post-operatively. However, there was a significant difference in pain levels at 24 hours in the nerve-block group (average NRS=1 vs. 8.2, p < 0.01). Opioid use post-operatively was lower in the nerve-block group (25%) as compared to the control group (100%). There was no difference in the average length of stay between the two groups.
Pain intensity and opioid use were significantly reduced with paravertebral block in this small cohort of patients. Given the success of this case series, paravertebral blocks continue to be promoted at our institution for this application and are offered to all patients during procedural planning for S-ICD placement. Given the relatively small sample size moving forward a randomized controlled trial will be needed to further validate the results of this series.