Pleural bupivacaine for pain treatment after nephrectomy

Small dose of naloxone as an adjuvant to bupivacaine in intrapleural infiltration after thoracotomy surgery: a prospective, controlled study

Background

Severe pain always develops after thoracotomy; intrapleural regional analgesia is used as a simple, safe technique to control it. This study was performed to evaluate whether a small dose of naloxone with local anesthetics prolongs sensory blockade.

Methods

A prospective, randomized double-blinded controlled study was conducted on 60 patients of American Society of Anesthesiologists statuses I and II, aged 18 to 60 years, scheduled for unilateral thoracotomy surgery. After surgery, patients were randomly divided into two groups: through the intrapleural catheter, group B received 30 ml of 0.5% bupivacaine, while group N received 30 ml of 0.5% bupivacaine with 100 ng of naloxone. Postoperative pain was assessed using the visual analog pain scale (VAS). Time for the first request for rescue analgesia, total amount consumed, and incidence of postoperative complications were also recorded.

Results

The VAS score significantly decreased in group N, at 6 h and 8 h after operation (P < 0.001 for both). At 12 h after injection, the VAS score increased significantly in group N (P < 0.001). The time for the first request of rescue analgesia was significantly longer in group N compared to group B (P < 0.001). The total amount of morphine consumed was significantly lower in group N than in the bupivacaine group (P < 0.001).

Conclusions

Addition of a small dose of naloxone to bupivacaine in intrapleural regional analgesia significantly prolonged pain relief after thoracotomy and delayed the first request for rescue analgesia, without significant adverse effects.

Negative pressure versus loss of resistance technique for interpleural block

BACKGROUND

Loss of resistance is a commonly practiced technique among the trainees. But, for performing interpleural block (IPB), negative-pressure identification techniques have been popularized. This study was designed to evaluate the two techniques in trainee anaesthetists.

METHODS

Sixty American society of anaesthesiologist (ASA) grade 1 and 2 women scheduled for elective breast surgeries under general anaesthesia were recruited for the study. The patients were randomly assigned to receive IPB (25 mL of 0.5% bupivacaine with adrenaline 5 mg/mL) with either loss of resistance technique (group LR, n=45) or the negative-pressure technique (group NP, n=45). The success rate and ease of performance was evaluated by the number of attempts and time taken.

RESULTS

Higher first attempt success rate was observed in group LR (90%) when compared with group NP (80%), with a significantly shorter mean time to successful identification of interpleural space in the group LR (5 min) than in the group NP (5.8 min), P<0.01log rank test. All patients had satisfactory IPB and the median numbers of segments blocked were 7 (5-9) and 6 (5-7) in groups LR and NP, respectively. No significant complications were observed in any of the patients.

CONCLUSION

Both techniques are safe and effective, but the loss of resistance technique is associated with a higher first attempt success rate performed in a shorter time by trainee anaesthetists.