[Intrapleural analgesia]

Comparison of Intrapleural with Paravertebral Levobupivacaine Analgesia for Thoracoscopic Sympathectomy: A Randomized Controlled Study

Background:

Palmar hyperhidrosis is a benign disease of excessive sweating in the palm that exceeds the physiological state. Thoracoscopic sympathectomy is an effective surgical treatment for localized hyperhidrosis.

Aims:

The aim of this study was to compare paravertebral block (PVB) with intrapleural analgesia in thoracoscopic sympathectomy.

Settings and Design:

A total of 90 patients physical status American Society of Anesthesiologists Classes I or II scheduled for arthroscopic thoracoscopic sympathectomy were enrolled in this study.

Subjects and Methods:

Patients were randomly allocated into three groups; in the controlled (C) group, no regional block was performed. In the intrapleural (I) group or paravertebral (P) group using a volume of 20 ml of levobupivacaine 0.5%. The first request for analgesia postoperatively was our primary concern. Secondary outcomes included pain scores, the cumulative consumption of fentanyl during the 1^st postoperative day, pulmonary functions, blood gases, and complications.

Statistical Analysis Used:

Statistical analysis was done using Statistical Package for Social Sciences (SPSS 19.0, Chicago, IL, USA).

Results:

First request of analgesia in paravertebral group was statistically significantly longer when compared with either control or intrapleural group. In addition, total fentanyl dose was significantly higher in control group when compared with the other groups. Groups I and P showed statistically significant less pain scores, better pulmonary function, and blood gases when compared with control group.

Conclusion:

We concluded that either intrapleural or paravertebral analgesia compared with control group in thoracoscopic sympathectomy resulted in later request of analgesia, improved pain control, reduced analgesic requirements postoperatively, preservation of lung function and acid-base balance. The PVB, compared to intrapleural, had an advantage of longer and effective analgesia.

[Comparison of extrapleural and intrapleural analgesia with bupivacaine after thoracotomy]

OBJECTIVE

To compare the analgesic and the ventilatory effects as well as blood concentrations of bupivacaine, administered either in the extrapleural or interpleural space after posterolateral thoracotomy.

STUDY DESIGN

Randomized clinical trial.

PATIENTS

Twenty ASA class I and II patients, scheduled for elective thoracic surgery were randomly allocated either in the IP group (catheter inserted into the interpleural space) or the EP group (catheter inserted in extrapleural position, paravertebrally above the posterior parietal pleura).

METHODS

In the catheter, inserted at the Th4 level at the end of the surgical procedure, 20 mL of 0.5% bupivacaine were injected after full recovery from anaesthesia, with the thoracic drains clamped for 30 min. The injection was repeated every six hours. Pain was evaluated after a deep inspiration with a visual analog scale (VAS), before and 1.3 and 6 hours after the injection. Analgesia was considered as effective if the VAS score at the end of the first hour was less than 30 mm. Otherwise 0.1 mg.kg-1 of morphine was administered subcutaneously. The forced vital capacity (FVC) and the forced expiratory volume one second (FEV1) were measured preoperatively and on 1st (D1) and 2nd postoperative Day (D2). Blood samples for measurements of plasma bupivacaine concentrations were obtained at 5, 10, 20, 30, 60, 90, 120, 150, 180 and 250 min respectively after the first injection.

RESULTS

Bupivacaine provided a more rapid, deep and prolonged analgesia by extrapleural than by interpleural route. Analgesia was effective in 9 patients in EP group vs 4 patients in IP group (P < 0.05). Morphine requirements were 4 +/- 8 mg in EP group vs 17 +/- 10 mg in the IP group (P < 0.05). The FVC and FEV1 values were similarly decreased on D1, but recovery was better in EP group on D2 (P < 0.05). Bupivacaine peak concentrations in plasma were lower in EP group (0.86 +/- 0.42 microgram.mL-1) than in IP group (1.63 +/- 1.44 micrograms.mL-1), however the difference was not significant.

CONCLUSIONS

Extrapleural administration of bupivacaine provides better analgesia as the anaesthetic agent comes in closer contact with intercostal nerves and with lower risk of loss of agent through the pleural drainage. Therefore its use is recommended preferentially over the interpleural route for analgesia after posterolateral thoracotomy.