Date Published: March 7, 2018
Author(s): Ahmed Said Elgebaly.
The aim of the study was to assess the nitroglycerin patch as a new additive to Bier’s block and its impact on the effects and dose of lidocaine.
Forty patients of each sex belonging to ASA I or II underwent elective tendon repair surgeries of the forearm and hand. The patients were divided into two equal groups as follows: Group C received only lidocaine (1.5 mg/kg, 0.25%) and Group N received lidocaine (1.5 mg/kg, 0.25%) + 5 mg transcutaneous nitroglycerin patch. Onset and recovery times for sensory and motor block, visual analogue scale (VAS) scores for bandage pain, postoperative VAS score, analgesic requirements, patients’ satisfaction, and surgeons’ opinion were recorded.
Sensory block onset time was shorter in Group N (3.80 ± 1.0) than that in Group C (5.72 ± 1.46), and motor block onset time was shorter in Group N (10.72 ± 1.93) than that in Group C (13.56 ± 1.26). Sensory block recovery time was prolonged in Group N (10.56 ± 1.12) than Group C (6.88 ± 1.45), recovery time of motor block was prolonged in Group N (13.04 ± 1.57) than Group C (11.96 ± 1.72). Bandage pain had lower VAS scores in Group N. Postoperative VAS scores showed significant differences between both groups at the following points of measurement: 30 minutes, 1 hour, and 4 hours after bandage deflation. Postoperative analgesic effect was the longest in Group N (187.20 ± 60.79 min) than Group C (51.60 ± 25.28 min). Patients’ satisfaction and surgeons’ opinion were better in Group N than Group C.
Supplementation of Bier’s block with transcutaneous nitroglycerin patch reduces the lidocaine dose, the sensory and motor block onset times, VAS scores, and analgesic consumption intra- and postoperatively. Length of the block recovery times for the sensory and motor effects, duration of postoperative analgesic effect, and the first time to analgesic requirement improved the quality of Bier’s block with better patients’ satisfaction and surgeons’ opinion and had no adverse effects.
Bier’s block is a technique that is mostly used for providing anaesthesia and analgesia during the operation. Using additives with lidocaine may provide satisfactory anaesthesia and prolong the duration of postoperative analgesia .
After obtaining the approval from the native Ethics and Research Committee, written informed consent from all the study participants was obtained. A double-blind prospective randomized study enrolled 40 ASA physical status I or II patients of each sex, aged ≥18 years and undergoing elective tendon repair surgeries of the forearm. Patients who refused; patients with Reynauld’s disease, sickle-cell disease, crush injuries, and swelling or skin infection at the site of injection; and patients with a history of allergy to nitroglycerin or lidocaine and surgeries >60 minutes or <30 minutes were excluded from the study. Age, sex, weight, ASA physical status, duration, and type of surgery showed insignificant difference with regard to comparable demographic data (Table 1). Our study results showed that the addition of 5 mg transcutaneous nitroglycerin patch as adjuvant to Bier's block reduced the lidocaine dose to 1.5 mg/kg of 0.25% lidocaine; reduced the onset times of sensory and motor block, VAS scores, and analgesic consumption; prolonged the sensory and motor block recovery times and the duration of postoperative analgesic effect of Bier's block; delayed the first time to analgesic requirement; and improved the quality of Bier's block with no adverse effects. The major limitation of the present study was the current small sample size since we were able to enroll only 40 patients. More studies with high and sufficient sample sizes are required to confirm these results. We recommend further larger studies to determine the effect of different doses of lidocaine and nitroglycerin and other additives that can affect Bier's block conditions. From the results of the present study, we conclude that, the addition of 5 mg of transcutaneous nitroglycerin patch as supplementation to 1.5 mg/kg of 0.25% lidocaine for Bier's block reduced the dose of lidocaine, sensory and motor block onset times, VAS scores, and analgesic consumption. Length of the sensory and motor block recovery times, the duration of postoperative analgesic effect, and the first time to analgesic requirement improved the quality of Bier's block with better patients' satisfaction and surgeons' opinion and had no side effects. Source: http://doi.org/10.1155/2018/9674731