بررسی تأثیر انفوزیون بوپیواکائین و نرمال سالین در کنترل درد پس از توراکوتومی؛ کارآزمایی بالینی

Background: Pain control after posterolateral thoracotomy is very important for adequate respiration and to reduce pulmonary complications. Narcotic-induced respiratory depression requires different intercostal nerve block procedures with local anesthesia, such as bupivacaine, through an extrapleural catheter, paravertebral catheter and intrapleural injection in order to control pain and reduce narcotics consumption. The aim of this study is to determine the efficacy of bupivacain versus normal saline (N/S) in pain control after thoracotomy. Methods: In a single-blind clinical trial, forty patients were divided into two groups of 20 patients each. Group 1 (G.1) received a single dose (10 ml) of bupivacaine 0.5%, followed by continuous infusion of N/S (0.1 ml/kg/h) four hours after surgery. Group 2 (G.2) received a single dose (10 ml) of bupivacaine 0.5%, followed by a continuous infusion of bupivacaine (0.1 ml/kg/h) four hours after surgery. Postoperative pain was assessed every four hours for 48 hours by linear visual analog scale (VAS). If VAS > 5, then pethidine was injected at a dosage of 1 mg/kg/IM. VAS ≤ 3 was considered pain control. Results: TThe mean VAS at 8, 12, 16, 20 and 24 hours after surgery in G.1 was 7.6, 5.5, 6.6, 5.5 and 5.7, respectively, and in G.2 was 3.4, 3.7, 2.8, 2.1 and 1.9, respectively. There were significant differences between the two groups (for 12 hours P<0.001 and for other time points P=0.0001). During the 4-24 hour period after surgery, pain control in G.1 was 5% and in G.2 was 81%. The mean VAS at 28, 32, 36, 40, 44, and 48 hours after surgery in G.1 was 5.2, 5, 5.3, 4.4, 5.1, and 4.8, respectively, and in G.2 was 1.6, 1.8, 1.5, 1.6, 1.5 and 1.4, respectively, with a significant difference between the two groups (P<0.0001). In the first 24 hours, the mean of pethidine injection in G.1 was 3.7 and in G.2 was 0.6 (P<0.0001). In the second 24 hours, the mean pethidine injection in G.1 was 2.2 and in G.2 there was no need for pethidine (p<0.0001).Conclusion: Continuous extrapleural infusion of bupivacaine is effective in pain control and decreasing demand for narcotics after thoracotomy.