A new technique of continuous interscalene nerve block

Purpose: To describes a technique of indwelling interscalene catheter placement and to evaluate its complications. Methods: One hundred and twenty patients undergoing major shoulder surgery received interscalene nerve block (ISNB) and were studied in three groups. Group I ISNB using Winnie's technique; group 2 by Winnie's technique with nerve stimulator and group 3 by epidural needle and catheter technique with nerve stimulator. All patients received 20 mt bupivacaine 0.5% and group 3 patients received an additional bupivacaine 0.25% infusion. Diaphragmatic movements were measured sonographically on emergence from anesthesia. Complications were noted. A visual analogue scale (0-10) was used to assess pain four hours postoperatively. Results: Mean ipsilateral diaphragmatic movements were 4 +/- 8, 14 +/- 11 and 18 +/- 8 mm (mean +/- SD) in groups 1,2 and 3 respectively. This was less than contralateral movements in all three groups (P < 0.05), None of the patients in groups 2 and 3 reported postoperative pain, The block failed in 10% of group I patients: Complete ipsilateral phrenic nerve block occurred in 85% of the patients in group 1 35% of group 2 and 20% of group 3 (P < 0,05), Ipsilateral recurrent laryngeal nerve paralysis occurred in 20% of the patients in group 1, 5% of group 2 and in none of the patients in group 3 (P < 0.05). Homer's syndrome was noted in group 1 (30%), group 2 (12%) but not in group 3. None of the catheters in group 3 patients dislodged after an average use of 2.8 +/- 2.1 days. Conclusions: Indwelling catheter placement into the brachial plexus sheath as described in this communication was effective and associated with few complications.