Effect of Entonox on reducing the need for Pethidine and the Relevant Fetal and Maternal Complications for Painless Labor.
BACKGROUND
Pain relief during labour is one of the major concerns in obstetrics; severe labor pain causes fear of the next pregnancy, and interferes with the mother's family relationship.


OBJECTIVE
The aim of this study was to evaluate the analgesic effects of Entonox during labor on reducing the need for pethidine (Meperidine) and fetal-maternal complications.


METHODS
This double-blind randomized clinical trial was conducted on pregnant women who were candidates for vaginal delivery in Educational Hospitals of Mashhad University of Medical Sciences, Iran between January 2014 and November 2015. After entering into the inactive phase of labor, participants were randomly allocated to receive inhaled Entonox gas (n=200) or inhale Oxygen (n=200) as a control group. Mothers inhaled the gas at commencement of pain, and ceased as soon as the pain diminished, up to the end of the second stage of labor which was the neonate's birth. Main outcomes were pain score based on NRS (numerical rating scale), duration of delivery, required pethidine, maternal complications and satisfaction during labour. Chi-square and Independent T-test were used via SPSS for data analysis and P-value less than 0.05 was considered statistically significant.


RESULTS
Four-hundred pregnant women with a mean age of 26.4±5.9 years were studied. Complications such as nausea, vomiting, dizziness, and drowsiness were reported in 25% of the Entonox group and 23% in the control group (p=0.640). Mean of pain severity score during labor in the Entonox and control groups was 4.5±1.2 and 5.2±1.4, respectively (p<0.001). Pethidine requirement, significantly was lower in the Entonox group (31.6±11.8 versus 35.7±12.4; p<0.001).


CONCLUSIONS
In our study, Entonox significantly reduced pain during delivery without significant increase in maternal and neonatal complications.


BACKGROUND
The trial is registered at the Iranian Clinical Trial Registry (IRCT.ir) with the IRCT identification number IRCT2015102713159N6.


BACKGROUND
This research has been financially supported by Research Council of Mashhad University of Medical Sciences.
M.D., Associate Professor, Department of Anesthesiology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
Alireza Sharifian
AS
Attar
M.D., Resident of Anesthesiology, Department of Anesthesiology, Faculty of Medicine, Mashhad University of Medical Sciences, Iran.
Atefe Shirinzadeh
AS
Feizabadi
M.D., Associate Professor of Community Medicine, Department of Community Medicine, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
Lida
L
Jarahi
M.D., Fellowship of Gynecologic Oncology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
Laya Shirinzadeh
LS
Feizabadi
M.D., Fellowship of Anesthesia in Cardiac Surgery, Assistant Professor of Anesthesiology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
Shima
S
Sheybani
Analgesia; Entonox; Inhalation; Narcotics; Obstetrical; Pethidine