A double-blind, randomized controlled trial on the use of a 50:50 mixture of nitrous oxide/oxygen in pain relief during suction evacuation for the first trimester pregnancy termination.
BACKGROUND
This prospective study assessed the role of a 50:50 mixture of nitrous oxide (N2O) and oxygen for pain relief during the termination of first trimester pregnancies by suction evacuation under conscious sedation.


METHODS
Ninety women undergoing suction evacuation up to 12 weeks of gestation were randomized by a computer-generated randomization list and allocated using sealed envelopes to receive the N2O/O2 mixture or air during the operation. Pain scores during and after suction evacuation, post-operative side effects and satisfaction level were compared.


RESULTS
No statistically significant differences in pain scores, post-operative side effects and satisfaction levels were found between the two groups.


CONCLUSIONS
N2O/O2 did not reduce the pain level during suction evacuation for the first trimester pregnancy termination under conscious sedation.
Kan
Anita Sik Yau
AS
Department of Obstetrics and Gynaecology, Operation Theatre Service, Queen Mary Hospital, The University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China. kansy@ha.org.hk
Caves
Natalie
N
Wong
Sylvia Yuen Wai
SY
Ng
Ernest Hung Yu
EH
Ho
Pak Chung
PC
D000028:Abortion, Induced; D000293:Adolescent; D000328:Adult; D001007:Anxiety; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D009609:Nitrous Oxide / Q000627:therapeutic use*; D010100:Oxygen / Q000627:therapeutic use*; D010146:Pain; D017060:Patient Satisfaction; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D013396:Suction; D014599:Uterus / Q000033:anatomy & histology
D009609:Nitrous Oxide; D010100:Oxygen