An Evaluation of the Effect of Morphine on Abdominal Pain and Peritoneal Irritation Signs in Patients with Acute Surgical Abdomen

Acute surgical abdomen is one of the most common emergency surgical causes all over the world and also one of the most important abdominal pain causes which is sometimes intolerable for the patients referring to the emergency departments. Diagnosis and planning for operation in these cases is based on time-demanding serial examinations and results of paraclinical data. In this waiting period, patients have to tolerate pain.Therefore, we aimed to study the hypothesis that relieving pain has no influence on valuable findings in physical examination. This double blind randomized clinical trial was carried out on 120 patients above 12 years old referred to an emergency department of a referral hospital with acute abdomen. Patients were divided into two groups of receiving intravenous placebo and Morphine randomly. Pain score, change in tenderness as well as change in rebound tenderness before and after receiving morphine or placebo were measured based on Numeric Pain Assessment Scale. Statistically significant difference was observed between both groups regarding the mean pain score. Prevalence of tenderness and rebound tenderness after medication administration revealed a significant difference between two groups. Furthermore, pain and tenderness showed a significant decrease in patients receiving morphine also a significant difference occurred in rebound tenderness between two groups. Despite the fact that opioid analgesics decrease pain in patients with acute surgical abdomen, they do not tend to eliminate required diagnostic data being obtained from physical examination like tenderness and rebound tenderness. Surprisingly, all the acute abdomen cases had rebound tenderness after morphine administration. Therefore, this research advises a cautious usage of morphine in patients with acute abdomen.