عنوان مقاله [English]
Introduction: The aim of this study was to determine the efficacy of entonox inhalation on pain intensity and duration of delivery.
Material and Methods: This study was performed in Shoushtar city, south of Iran. In a random controlled clinical trail, 120 women with term pregnancy were randomly divided into 2 equal groups; Entonox group and control group. The study group received inhaled nitrous oxide premixed with oxygen (50%:50%) and control group only inhaled oxygen. Visual analog scale and McGill Pain Questionaire was used to measure the intensity of the labor pain. The groups were compared for labor pain, duration of the labor, method of delivery, and the Apgar scors of the newborn. Statistical analyses were performed by independent sample t test and chi squar test. p<0.05 was considered as statistically significant.
Results: The mean labor pain intensity was decreased significantly after administration of Entonox compared with the control group (4.17v6.78, P<0/001).The pain also decreased by increasing the concentration of inhaled nitrous oxide. There was not significantly difference between the two groups in the mean duration of active phase of the labour (p=0.2) and the neonatal Apgar scores (p=0.69).Fewer patients in the Entonox group required cesarean section compared with the control group, but the difference was not significant (p=0.48). 78.3% of the women had satisfaction from the analgesic effect of Entonox during the labor.
Conclusion: Nitrous oxide (50%) with oxygen (50%) inhalation provides adequate pain relife for many women during the first and second stages of labor.