Pre-emptive local anesthesia for needlescopic video-assisted thoracic surgery: a randomized controlled trial.

OBJECTIVE: Studies in other surgical specialties have suggested that pre-emptive wound infiltration using a local anesthetic may reduce post-operative pain. We report the first randomized trial to assess the use of pre-emptive local anesthesia in video-assisted thoracic surgery (VATS). METHOD: Thirty-one consecutive patients undergoing bilateral needlescopic VATS sympathectomy for palmar hyperhidrosis were studied prospectively. Each patient acted as their own control. For each patient, one side was randomized to receive 10ml 0.5% bupivicaine injected to the port sites before incision, and the contralateral control side to receive 10ml saline. Pain severity on a visual analog scale (VAS) was recorded for each chest side at 4h, 1 day and 7 days following surgery. All patients were blinded to the results of randomization throughout the study. RESULTS: Follow up was complete for all patients. At 7 days after surgery, wound pain was significantly reduced by pre-emptive local anesthesia, with 10 (62.5%) of the 16 patients having residual pain reporting less pain on the pre-treated side (p=0.039). There was a trend for reduced pain on the pre-treated side at the other time points. Pain reduction by pre-emptive local anesthesia was not correlated with any demographic or clinical variable. Chest wall paresthesia distinct from localized wound pain was noted by six patients (19.4%), but was not reduced by pre-emptive local anesthesia. Overall, the post-operative discomforts felt by the patients after needlescopic VATS were mild, and did not cause significant functional disturbances. CONCLUSION: Pre-emptive wound infiltration with a local anesthetic may reduce post-operative wound pain in needlescopic VATS procedures.

Analgesic effect of electroacupuncture in postthoracotomy pain: a prospective randomized trial.

BACKGROUND: The role of electroacupuncture in postthoracotomy pain control is uncertain. We conducted a pilot study to evaluate the role of electroacupuncture in the management of early postthoracotomy wound pain. METHODS: A total of 27 patients with operable non-small cell lung carcinoma who received thoracotomy were recruited and randomized to receive either electroacupuncture or sham acupuncture in addition to routine oral analgesics and patient-controlled intravenous analgesia for postoperative pain control. All patients received acupuncture twice daily with visual analog pain score recorded for the first 7 postoperative days. Specific chest acupoints (LI 4, GB 34, GB 36, and TE 8) were targeted. Patient-controlled analgesia was used for the first 3 postoperative days in all patients, and the cumulative dosage used was recorded. RESULTS: Two patients were excluded after randomization because of complications unrelated to acupuncture. Interventions and data collection were completed for the remaining 25 patients (13 in the electroacupuncture group; 12 in the sham acupuncture group). There was a trend for lower visual analog scale pain scores in the electro-acupuncture group between postoperative days 2 and 6, although this did not reach statistical significance. The cumulative dose of patient-controlled analgesia morphine used on postoperative day 2 was significantly lower in the electroacupuncture group (7.5 +/- 5 mg versus 15.6 +/- 12 mg; p < 0.05). Such delay of onset of pain control may be related to the frequency of electroacupuncture used. CONCLUSIONS: Electroacupuncture may reduce narcotic analgesic usage in the early postoperative period. A prospective randomized controlled trial using different electroacupuncture frequency is warranted to verify this benefit.

Release of nitric oxide and endothelium-derived hyperpolarizing factor (EDHF) in porcine coronary arteries exposed to hyperkalemia: effect of nicorandil.

BACKGROUND: Although the detrimental effect of hyperkalemia on coronary endothelium has been reported, there is no direct evidence regarding the effect of hyperkalemic exposure on nitric oxide (NO) release from the coronary endothelium. In addition, it is unclear whether nicorandil, a KATP channel opener, used as hyperpolarizing cardioplegia or added in hyperkalemic cardioplegic solution may protect endothelial function during cardiac surgery. The present study was designed to clarify NO release and the function of endothelium-derived hyperpolarizing factor (EDHF) in coronary circulation with respect to the effect of hyperkalemia and nicorandil. METHODS: Nitric oxide was measured by using a NO-specific electrode, and EDHF-mediated relaxation was investigated in a myograph. Substance P- and calcium ionophore A23187-induced NO release was compared in porcine left circumflex coronary arteries before and after 1-hour exposure to 20 mM potassium (K+) at 37 degrees C. In coronary microarteries (diameter 200 to 450 microm), precontracted with U46619, in the presence of indomethacin (7 microM), NG-nitro-L-arginine (300 microM), and oxyhemoglobin (20 microM), EDHF-mediated relaxation was induced by bradykinin (-10 to -6.5 log M) after incubation with Krebs (control) or 20 mM K+ with or without 10 microM nicorandil at 37 degrees C for 1 hour. RESULTS: Neither substance P (58.8 +/- 5.0 versus 66.2 +/- 7.2 nmol/L) nor A23187 (86.6 +/- 9.0 versus 82.4 +/- 9.2 nmol/L in control) induced NO release was altered by hyperkalemic exposure (p > 0.05). In contrast, EDHF-mediated relaxation was decreased from 84.2% +/- 3.8% to 42.3% +/- 6.0% (p < 0.001) that was partially restored by nicorandil (50.7% +/- 5.5%, p < 0.05). CONCLUSIONS: Exposure to potassium at 20 mM does not affect NO release but impairs EDHF-mediated relaxation in coronary arteries. Supplementation of nicorandil in hyperkalemic cardioplegia may provide a protective effect on EDHF-related endothelial function.