RESUMO
<p><b>OBJECTIVE</b>To explore the effect of lappaconitine on patient-controlled intravenous analgesia (PCIA) and serum complement 3 and 4 (C3 and C4) levels of cancer patients undergoing rectum surgery.</p><p><b>METHODS</b>Totally 60 patients, who were scheduled for rectum carcinoma surgery, were recruited to the study and assigned in 3 groups, the blank control group, the tramadol group, and the lappaconitine group, 20 in each group. Lappaconitine (8 mg) was intravenously dripped to patients in the lappaconitine group 30 min before ending the operation. PCIA started as soon as the end of the surgery and the total dose of lappaconitine was 36 mg. Patients of the tramadol group were treated with tramadol (100 mg) intravenously within 30 min before ending the operation. The dripping was completed within 30 min. PCIA was started as soon as the end of the surgery and the total dose of lappaconitine was 36 mg. Tramadol (100 mg) was intravenously dripped to patients in the tramadol group 30 min before ending the operation. PICA was started as soon as the end of the surgery and the total dose of tramadol was 900 mg. Pethidine (50 mg) and droperidol (2. 5 mg) was intramuscularly injected to patients in the blank control group for pain relief according to their complaints. Pain degrees were assessed by visual analog scale (VAS) 12 h before surgery, 12, 24, 48, and 72 h after surgery. Blood samples were withdrawn at the same time point. Contents of serum C3 and C4 were determined by immunoturbidimetry.</p><p><b>RESULTS</b>VAS scores of the blank control group were significantly higher after surgery than before surgery (P <0. 01). There was no statistical difference in VAS scores between before surgery and after surgery in the tramadol group and the lappaconitine group (P >0. 05). VAS scores were significantly lower at each post-surgery time point in the tramadol group and the lappaconitine group than in the blank control group with statistical difference (P < 0.01). There was no statistical difference in VAS scores at each post-surgery time point between the tramadol group and the lappaconitine group (P >0. 05). Compared with before surgery, contents of serum C3 and C4 significantly decreased in all of the three groups at 12, 24, and 48 h after surgery (P < 0.05, P < 0.01). They recovered to the pre-surgery level till 72 h after surgery (P > 0.05). Serum C3 and C4 contents at 48 h after surgery were higher in the tramadol group than in the blank control group (P < 0.05). Serum C3 and C4 contents at 24 and 48 h after surgery were higher in the lappaconitine group than in the blank control group (P < 0.05). There was no statistical difference in serum C3 and C4 contents at each time point between the tramadol group and the lappaconitine group (P > 0.05). VAS scores were obviously negatively correlated with serum contents of C3 and C4 (r = -0.622, r = -0.649, P < 0.01).</p><p><b>CONCLUSIONS</b>Lappaconitine (used at the dose in this study) showed better pain relief effect after surgery. Besides, it could inhibit the surgic wound and pain, and elevate serum contents of C3 and C4.</p>