Synergistic Effect Of Parenteral Diclofenac And Paracetamol In The Pain Management Of Acute Limb Injuries

Injuries account for a large burden of mortality and morbidity in the state of Qatar and worldwide. Among all the acute injuries, limb injuries are very common. Immense pain of patients on presentation is the matter of concern and requires effective analgesia within the shortest possible time.

Most patients with acute limb injuries are treated with, the commonly used analgesics like non-steroidal anti-inflammatory drugs (NSAIDs), opioids, and paracetamol in the ED. The choice of analgesic should be established by its efficacy, logistics involved, and route of drug administration. Few studies reported that intravenous route is more effective than the intramuscular route, due to its faster absorption and ease of titration. In many ED's intramuscular injectable drugs like NSAIDs are commonly used. Being, readily available and technically faster to administer. There is concern about the use of IM diclofenac in some countries because of possible intramuscular complications; however, most are reported cases in a small proportion (<2 per million doses used). Oral medications are also very commonly used and usually self-administered by the patients with duration of onset being in minutes to an hour. There is good evidence about NSAIDs being the first line analgesic in the management of acute painful conditions such as renal colic. Intramuscular diclofenac is shown to provide safe, effective, and sustained pain relief in addition to being logistically easier to administer. Paracetamol being a centrally acting inhibitor of cyclooxygenases has been reported safe alternative to opioids and equally effective analgesic in the ED with fewer side effects and contraindications. In addition, paracetamol is reported to have the narcotic sparing effect, either alone or as an adjunctive treatment in different settings including post-op pain, cancer pain, and regional anesthesia. The synergistic effect of paracetamol with diclofenac in acute limb injury related- pain management lacks good-quality evidence.

Hamad General Hospital Emergency Department (HGH-ED) is the major emergency department (ED) in Doha; Qatar; and offers tertiary level care for emergency conditions. It is also one of the busiest ED's in the world with an annual patient attendance of 0.5 million. Patients with acute limb injuries account for about 25% of the total ED visits. At HGH-ED, intramuscular diclofenac is the analgesia of choice for the management of acute pain of moderate to severe intensity. However, 40-50% of these patients require additional analgesia in the form of opioids or paracetamol. The efficacy of combined analgesia approach, and the difference by route of drug administration in acute ED pain management is yet to be assessed. Therefore investigators proposed a large, well designed, randomized, double- blind trial to develop high-quality evidence. This study aims to assess the efficacy of paracetamol in addition to diclofenac, and compare the difference between oral and intravenous paracetamol administration in acute limb injury pain management in the ED.