بررسی تأثیر غلظت گاز N2O در پیشگیری از اسپاسم حنجره بعد از عمل سزارین: کارآزمایی بالینی تصادفی

Backgound and Objective: Laryngeal spasm is one of dangerous and urgent complications after tracheal extubation, due to hypoxemia. This event can lead to mortality or complications such as pulmonary aspiration, pulmonary edema, bradycardia and hypoxemia. The aim of this research was to evaluate the effect of increased N2O concentration on the incidence of laryngeal spasm. This research was funded by Rafsanjan University of Medical Sciences. Conflict of interest not declared and Ethics Committee of the University approved the study. Materials and Methods: This study was conducted as a single blind clinical trial on 440 women undergoing elective cesarean section. Patients were divided in to two groups by simple randomization. Two groups had equal anesthetic technique monitoring of cardiovascular and respiratory system and monitoring SPO2 and had same surgical incision . The only difference was N2O concentration: 50% in one group and 70% in another. The two groups compared for incidence of laryngeal spasm after extubation, hypoxemia, nausea and vomiting. Results: Statistical analysis showed that laryngeal spasm occurred in six (2.73%) from 220 patients in 50% N2O group and in none in 70% N2O group (p=0.030). No patient in both groups had complications of N2O administration such as hypoxemia, nausea and gaseous distension of bowels. Conclusion: Enhanced analgesia using increased N20 concentration prevents laryngeal spasm after tracheal extubation in patients under going cesarean section. Key words: Laryngospasm, General anesthesia, Cesarean section, Nitrous oxide Funding: This research was funded by Rafsanjan University of Medical Sciences. Conflict of interest: None declared. Ethical approval: The Ethics Committee of Rafsanjan University of Medical Sciences approved the study.