Effects of interscalene brachial plexus block to intra-operative hemodynamics and postoperative pain for arthroscopic shoulder surgery

Abstract

Background: Although arthroscopic shoulder surgery is less invasive and painful than open shoulder surgery, it can often cause intra-operative hemodynamic instability and severe post-operative pain. This study was conducted to investigate the efficacy of the interscalene brachial plexus block (IBPB) on intra-operative hemodynamic changes and post-operative pain during arthroscopic shoulder surgery.

Methods: After institutional review board approval, 50 consecutive patients that had undergone arthroscopic shoulder surgery under general anesthesia were randomly assigned to one of two groups to evaluate intra-operative hemodynamic changes and post-operative pain control. Group 1 patients received an IBPB with 10 ml of normal saline guided by a nerve stimulator before induction, and Group 2 patients received 10 ml of 0.5% ropivacaine hydrochloride with the same technique. The heart rate and systolic and diastolic blood pressures were recorded before the incision and 1, 3, 5, 10, and 20 minutes after the incision. Pre-operative and post-operative pain was evaluated with a visual analog scale 1, 3, 6, 12, and 24 hours after surgery. The patients were given tramadol as a rescue medication option. The total volume of tramadol that was injected was also evaluated over the same intervals.

Results: Group 2 showed significantly lower systolic and diastolic blood pressures and heart rates intra-operatively compared to Group 1 (P < 0.05). The visual analog scale pain scores, except at 24 hours after surgery, were significantly lower in Group 2 (P < 0.05). The total tramadol consumption significantly reduced in Group 2 (P < 0.05).

Conclusions: IBPB effectively controlled the hemodynamic changes that occurred during arthroscopic shoulder surgery as well as post-operative pain.

Keywords: Arthroscopy; Brachial plexus; Hemodynamics; Nerve block; Pain; Shoulder.

Figures

Fig. 1

Changes in systolic arterial blood pressure (A), diastolic arterial blood pressure (B) and heart rates (C). Data are expressed as mean ± SD. There were significant differences between the two groups after skin incision in systolic arterial blood pressure, diastolic arterial blood pressure and heart rates. Group 1 (n = 25) received an interscalene brachial plexus block with normal saline 10 ml guided by nerve stimulator before induction, and Group 2 (n = 25) received the same technique with 0.5% ropivacaine 10 ml. Tb: before incision, T1: 1 minute after incision, T3: 3 minutes after incision, T5: 5 minutes after incision, T10: 10 minutes after incision, T15: 15 minutes after incision, T20: 20 minutes after incision. *P < 0.05 compared with Group 1, †P < 0.05 compared with Tb in group 1, ‡P < 0.05 compared with Tb in group 2.

Fig. 2

Visual analog scale (VAS) at passive exercise before surgery and after 1, 3, 6, 12 and 24 h postoperatively. There were significant differences in Group 2 compared with Group 1 except at 24 hours postoperatively. Group 1 (n = 25) received an interscalene brachial plexus block with normal saline 10 ml guided by nerve stimulator before induction, and Group 2 (n = 25) received the same technique with 0.5% ropivacaine 10 ml. Tb: preoperative, T1 h: 1 hour postoperatively, T3 h: 3 hours postoperatively, T6 h: 6 hours postoperatively, T12 h: 12 hours postoperatively, T24 h: 24 hours postoperatively. *P < 0.05 compared with Group 1, †P < 0.05 compared with Tb in group 1, ‡P < 0.05 compared with Tb in group 2.

Fig. 3

The incidence of additional analgesic requirements after 1, 3, 6, 12 and 24 h postoperatively. There were significant increases in group 1 except at 24 hours after surgery. Group 1 (n = 25) received an interscalene brachial plexus block with normal saline 10ml guided by nerve stimulator before induction, and group 2 (n = 25) received a same technique with 0.5% ropivacaine 10 ml. *P < 0.05 compared with Group 1.