Intravenous paracetamol improves the quality of postoperative analgesia but does not decrease narcotic requirements

Paracetamol, a centrally acting inhibitor of cyclooxygenase, has less gastrointestinal and platelet-inhibiting side effects and is clinically better tolerated than nonsteroidal anti-inflammatory drugs. Therefore, it will be ideally suited for postoperative pain relief. In this prospective, double-blind, randomized, placebo-controlled study, we evaluated the analgesic efficacy, opioid-sparing effect and effects on opioid-related adverse effects of intravenous (IV) paracetamol in combination with IV morphine after lumbar laminectomy and discectomy. Forty patients were divided into 2 groups (n = 20 each) to receive either paracetamol 1 g (group 1) or 0.9% NaCl 100 ml (group 2) at the end of the operation and at 6-hour intervals over 24 hours. IV patient-controlled analgesia with morphine was used as a rescue analgesic in both groups. Pain was evaluated at rest and on movement at the 1st, 2nd, 4th, 6th, 12th, 18th, and 24th hours using a visual analog scale. Hemodynamic parameters, morphine usage, patient satisfaction, and probable side effects were also evaluated. Pain scores at rest and on movement at the 12th, 18th, and 24th hours were significantly lower in group 1 (P < 0.001). Morphine consumption was not statistically significantly different between the groups (P > 0.05). Vomiting in group 2 was significantly higher (P = 0.027). Significantly more patients in the paracetamol group rated their pain management as excellent (45% vs. 5%). Although repeated IV paracetamol usage after lumbar laminectomy and discectomy did not demonstrate a significant opioid-sparing effect, it did decrease visual analog scale scores at certain evaluation times and incidence of vomiting and increase patient satisfaction.