Tehran University Medical Journal

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Background: Acute lung injury (ALI) is a pulmonary pathology occuring in context of infection, trauma, burn, and sepsis. Tissue injury and release of chemical mediators result in tissue damage and organ failure especially respiratory failure. Many therapeutic modalities including vitamin E, allopurinol, and N-acetylcystein (NAC) have been used to decrease levels of inflammatory factors and to control and improve signs and symptoms. The antioxidant feature of NAC induces synthesis of glutathione- the scavenger of free radicals- and increase respiratory drive and PaO₂. In time diagnosis of ALI, prompt institution of treatment will reduce mortality and morbidity in critical illness.
Methods: This open label analytical clinical trial included a total of 50 patients admitted in the ICU ward of Sina University Hospital. They were randomly divided into two groups of 25, the case group received NAC 150mg/kg in 100ml Normal saline within 20 minutes then 50mg/kg in 100ml Normal saline within 4 hr after that 50mg/kg daily for three days. The controls received only normal saline. Oxygenation and ventilation parameters were studied In both groups.
Results: There were no significant difference between the groups in terms of demographic indices, mean SpO₂, ABG values, mortality rates, and clearing of chest x-rays. The best outcome was seen in young traumatic patients.

Conclusion: In this relatively small group of patients presenting with an established ALI/ ARDS subsequent to a variety of underlying disease, intravenous NAC treatment during first four days neither significantly improved systemic oxygenation nor reduced the need for ventilatory support.

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Background: Postoperative pain is one of the most common complications following laparoscopic cholecystectomy. Because the majority of the analgesic drugs including opioids and nonsteroidal anti-inflammatory drugs have many side effects, using drugs with lesser side effects is beneficial. The aim of this study was to evaluate the effect of N-acetylcysteine on the pain after laparoscopic cholecystectomy.

Methods: In a randomized clinical trial, in two university-affiliated teaching hospitals in Babol City (Shahid Beheshti and Shahid Yahyanezhad Hospitals), Iran, from August 2015 to March 2015, a total number of 38 patients with age of 20-50 years, who were candidates for laparoscopic cholecystectomy with American Society of Anesthesiologists Class-I were chosen and randomly assigned into two groups. The night before operation, 1200 mg oral N-acetylcysteine is given to intervention group. Also, they received 600 mg IV N-acetylcysteine in the morning before operation. In the control group, two vitamin C effervescent tablets as placebo were given at night before operation and 3 ml sterile water as placebo was injected in the morning of operation. Amount of pethidine consumption and the changes in hemodynamic in two groups was recorded and analyzed at 24 hours after operation.

Results: The average of patients age was not significant different between two groups (P=0.23). Average of pain score in placebo group was 3.5 and in N-acetylcysteine group was 2.7 that it was not significant difference between two groups (P=0.06). Average of pethidine consumption in placebo group was 52 mg and in N-acetylcysteine group was 29 mg in 24 hours, that the difference was statistically significant between two groups (P=0.01) Conclusion: As the results of the study, it can be concluded that the anti-inflammatory effects N- acetylcysteine can inhibit the function of lipoproteins and prostaglandins, reduced glutathione peroxidase and dismutase has been restored and can be used to treat pain or analgesic dose reduction. In this study the N-acetylcysteine  has reduced  pain after laparoscopy and analgesic dose of mepridine.