A Novel Approach for Pain Management in Cardiac Surgery via Median Sternotomy: Bilateral Single-Shot Paravertebral Blocks

Abstract

Regional analgesia has entered cardiac anesthesia in the form of spinal or epidural analgesia. However, the risk of spinal or epidural hematoma is a constant worry. Alternative regional techniques might be applicable in cardiac surgery. The purpose of this study is to present a novel technique of bilateral single-shot paravertebral blocks (BSS-PVB) for cardiac surgery via median sternotomy and compare its efficacy versus high thoracic epidural analgesia (TEA). Fifty-two patients were compared in this prospective cohort audit. In 26 patients, cardiac surgery was performed using low-dose fentanyl/BSS-PVB (bilateral blocks of 3 mL bupivacaine 0.5% each, T1-7) and general anesthesia; in another 26 patients, TEA (bupivacaine 0.125% at 10 mL/hour) and general anesthesia were used. Patients were assigned to cohorts according to their preoperative data and types of surgery. All patient data are shown as mean +/- SD; pain scores were compared between groups using the t test immediately, 6 hours, and 24 hours after surgery (P < .05). In the BSS-PVB-group (19 men, 7 women), mean age was 65 +/- 11 years, weight 74 +/- 16 kg, ejection fraction 59% +/- 12%, and duration of surgery 130 +/- 27 minutes; in the TEA-group (17 men, 9 women), mean age was 63 +/- 10 years, weight 75 +/- 16 kg, ejection fraction 58% +/- 12%, and duration of surgery 113 +/- 27 minutes. These data and preoperative comorbidity variables were not significantly different between the two groups. In each group, 18 patients underwent off-pump coronary artery bypass grafting, 3 on-pump and 5 mitral valve replacements. All patients were successfully immediately extubated. Postoperative pain scores were at any point significantly lower with TEA, immediately at 2.4 +/- 2.2 versus 3.7 +/- 2.6, at 6 hours at 1.1 +/- 1.5 versus 2.4 +/- 1.8, and at 24 hours at 1.0 +/- 1.4 versus 2.3 +/- 1.6 (0 = no pain, 10 = maximum pain). There was no complications related to epidural catheter placement or BSS-PVB. Using both techniques, immediate extubation after cardiac surgery is feasible; TEA provides better pain relief after cardiac surgery than BSS-PVB.

Pain relief following sternotomy in conventional cardiac surgery: A review of non neuraxial regional nerve blocks

“…[ 12 ] Another two studies compared paravertebral block with thoracic epidural anesthesia (TEA). [ 13 14 ] While El shora et al . found comparable analgesia in both groups, Oliver and colleagues reported TEA to be superior.…”

“…found comparable analgesia in both groups, Oliver and colleagues reported TEA to be superior. [ 13 14 ] This difference may be justified as due to lack of use of continuous infusion in the later. Further studies are required to support or refute these findings.…”

Regional anesthesia for sternotomy and bypass—Beyond the epidural

“…In a further randomized study comparing 50 adult patients undergoing CABG to either receive continuous bilateral thoracic paravertebral infusion or subcutaneous infusion of lignocaine, no difference was found in morphine consumption at 48 hours, pain scores, nausea and vomiting, or respiratory function. 39 A single non-randomized study has compared epidural directly with landmark bilateral, single shot, paravertebral blocks 40 in adult undergoing ultra-fast track cardiac surgery.…”

Chronic Poststernotomy Pain

“…[108][109][110][111][112][113][114][115][116][117][118] Parasternal Intercostal and Paravertebral Blocks Parasternal intercostal and paravertebral blocks reduce acute postoperative pain. [119][120][121][122] Despite this, there is no evidence that either has an effect on chronic poststernotomy pain. 121,123 Intrapleural Injection Intrapleural local anesthetic injections have been utilized for pain control following thoracotomy with mixed results.…”