Patient-controlled intravenous tramadol versus patient-controlled intravenous hydromorphone for analgesia after secondary cesarean delivery: a randomized controlled trial to compare analgesic, anti-anxiety and anti-depression effects

INTRODUCTION: This study aimed to compare the postoperative analgesic effects of tramadol and hydromorphone for secondary cesarean delivery (CD) as well as their anti-anxiety and anti-depression properties. METHODS: A total of 106 patients receiving secondary CD under spinal anesthesia were randomly allocated to the tramadol group (n=53) and the hydromorphone group (n=53). Each group received patient-controlled intravenous analgesia using flurbiprofen 4 mg/kg combined with tramadol (4 mg/kg) or hydromorphone (0.04 mg/kg) immediately after the surgery. Postoperative pain numerical rating scale (NRS) for incision and visceral pain, hospital anxiety and depression scale (HADS), early walking time and length of hospital stay were assessed. RESULTS: Patients in the tramadol and hydromorphone groups exhibited equivalent incision pain NRS at different time points (P>0.05). Visceral pain in the tramadol group was higher than that in the hydromorphone group at postoperative 4 hours (2.9 [1.2] vs 2.3 [1.4], P=0.011) and 8 hours (2.4 [1.1] vs 1.8 [1.1], P=0.028). One week after the surgery, the patients in the tramadol group, as compared to the hydromorphone group, had lower anxiety scores (1.9 [3.5] vs 3.6 [4.1], P=0.033) and depression scores (0.8 [1.3] vs 2.7 [4.1], P=0.023). In addition, early walking time (25.3 [7.0] hours vs 29.3 [9.6] hours, P=0.016) and length of hospital stay (2.9 [0.8] days vs 3.3 [0.8] days, P= 0.008) after the surgery in the tramadol group were less than those in the hydromorphone group. CONCLUSION: Postoperative intravenous analgesia with tramadol or hydromorphone for secondary CD provides comparable analgesic effects on incision pain. Tramadol is less effective in controlling visceral pain compared to hydromorphone. However, tramadol can help to alleviate anxiety and depression in the early postpartum period, improve patients’ early mobilization and shorten their hospital stay. CLINICAL TRIAL NUMBER AND REGISTRY URL: No: ChiCTR-IIR-17011043; URL: www.chictr.org.cn.