{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T01:59:32Z","timestamp":1760147972218,"version":"build-2065373602"},"reference-count":12,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2023,3,20]],"date-time":"2023-03-20T00:00:00Z","timestamp":1679270400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100002842","name":"Chiang Mai University","doi-asserted-by":"publisher","award":["CMU-2566"],"award-info":[{"award-number":["CMU-2566"]}],"id":[{"id":"10.13039\/501100002842","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Medicina"],"abstract":"<jats:p>Aim and\u00a0Objective: To compare the analgesic effectiveness of the patient-controlled inhaled nitrous oxide (Entonox\u00ae) with intravenous opioids (pethidine\/midazolam) in reducing pain during minor gynecological operative procedures, including manual vacuum aspiration (MVA), fractional curettage and dilatation and curettage. Materials and Methods: Patients undergoing minor gynecological procedures from August 2021 to December 2022 were randomized to receive nitrous oxide or intravenous pethidine (50\u201375 micrograms) plus midazolam (2 mg). Pain scores during and post-procedure, satisfaction level, and side effects were assessed and compared. Results: A total of 106 patients met the inclusion criteria, including 53 in the pethidine\/midazolam group and 53 in the nitrous oxide group. Baseline characteristics were comparable (p-value &gt; 0.05). Pain scores during, immediately and 30 min after procedures were not significantly different in two groups (4.94 \u00b1 3.15, 2.74 \u00b1 2.57, 1.58 \u00b1 2.13 vs. 5.47 \u00b1 2.80, 2.98 \u00b1 2.70, 1.64 \u00b1 2.70; p-value: 0.174, 0.634, 0.889, for pethidine\/midazolam vs. nitrous oxide group, respectively. Satisfaction scores were comparable in both groups (p-value &gt; 0.05). However, the rate of side effects was significantly lower in the nitrous oxide group (3.8% vs. 28.3%; p-value 0.001). Additionally, the discharge scores showed a significantly faster recovery time in the nitrous oxide group at 60 and 90 min after the procedure; median (IQR): 10 (9\u201310) vs. 9 (8\u201310) and 10 (10\u201310) vs. 10 (8.5\u201310); p-value 0.002 and 0.029, respectively). Conclusions: Nitrous oxide is as effective as pethidine\/midazolam for pain relief in minor gynecological operative procedures but associated with significantly lower side effects and significantly faster recovery time.<\/jats:p>","DOI":"10.3390\/medicina59030611","type":"journal-article","created":{"date-parts":[[2023,3,20]],"date-time":"2023-03-20T05:46:42Z","timestamp":1679291202000},"page":"611","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Effectiveness of Nitrous Oxide versus Pethidine\/Midazolam for Pain Relief in Minor Gynecological Operative Procedures: A Randomized Controlled Trial"],"prefix":"10.3390","volume":"59","author":[{"given":"Napas","family":"Lohtrakul","sequence":"first","affiliation":[{"name":"Department of Obstetrics and Gynecology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Chanane","family":"Wanapirak","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynecology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3389-6478","authenticated-orcid":false,"given":"Theera","family":"Tongsong","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynecology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,3,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"9","DOI":"10.2344\/0003-3006(2007)54[9:AIUTAO]2.0.CO;2","article-title":"Advances in understanding the actions of nitrous oxide","volume":"54","author":"Emmanouil","year":"2007","journal-title":"Anesth. Prog."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"347","DOI":"10.1111\/j.1600-0528.1983.tb01390.x","article-title":"Nitrous oxide-oxygen sedation in dental care","volume":"11","author":"Hallonsten","year":"1983","journal-title":"Community Dent. Oral. Epidemiol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"444","DOI":"10.1016\/j.jemermed.2019.06.026","article-title":"Analgesic Effect of Nitrous Oxide\/Oxygen Mixture for Traumatic Pain in the Emergency Department: A Randomized, Double-Blind Study","volume":"57","author":"Gao","year":"2019","journal-title":"J. Emerg. Med."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"471","DOI":"10.4253\/wjge.v9.i9.471","article-title":"Colonoscopy quality with Entonox","volume":"9","author":"Robertson","year":"2017","journal-title":"World J. Gastrointest. Endosc."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"6002","DOI":"10.19082\/6002","article-title":"Effect of Entonox for pain management in labor: A systematic review and meta-analysis of randomized controlled trials","volume":"9","author":"Sheyklo","year":"2017","journal-title":"Electron. Physician"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"e37420","DOI":"10.5812\/aapm.37420","article-title":"A Randomized Controlled Trial Comparing Use of Enthonox with Pethidine for Pain Relief in Primigravid Women During the Active Phase of Labor","volume":"6","author":"Mobaraki","year":"2016","journal-title":"Anesth. Pain. Med."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"595","DOI":"10.1016\/j.jmig.2015.01.005","article-title":"Inhalation analgesia with nitrous oxide versus other analgesic techniques in hysteroscopic polypectomy: A pilot study","volume":"22","year":"2015","journal-title":"J. Minim. Invasive Gynecol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"239","DOI":"10.1016\/j.contraception.2016.09.006","article-title":"Nitrous oxide for pain management during in-office hysteroscopic sterilization: A randomized controlled trial","volume":"95","author":"Schneider","year":"2017","journal-title":"Contraception"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1192","DOI":"10.1097\/AOG.0000000000002915","article-title":"Nitrous Oxide Compared with Intravenous Sedation for Second-Trimester Abortion: A Randomized Controlled Trial","volume":"132","author":"Thaxton","year":"2018","journal-title":"Obstet. Gynecol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"79","DOI":"10.1016\/j.contraception.2011.11.015","article-title":"A double-blind, randomized controlled trial of the use of a 50:50 mixture of nitrous oxide\/oxygen in legal abortions","volume":"86","author":"Agostini","year":"2012","journal-title":"Contraception"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"2606","DOI":"10.1093\/humrep\/del234","article-title":"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","volume":"21","author":"Kan","year":"2006","journal-title":"Hum. Reprod."},{"key":"ref_12","first-page":"403","article-title":"Effectiveness of paracervical block versus intravenous morphine during uterine curettage: A randomized controlled trial","volume":"94","author":"Thongrong","year":"2011","journal-title":"J. Med. Assoc. Thai"}],"container-title":["Medicina"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1648-9144\/59\/3\/611\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T18:58:55Z","timestamp":1760122735000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1648-9144\/59\/3\/611"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,3,20]]},"references-count":12,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2023,3]]}},"alternative-id":["medicina59030611"],"URL":"https:\/\/doi.org\/10.3390\/medicina59030611","relation":{},"ISSN":["1648-9144"],"issn-type":[{"type":"electronic","value":"1648-9144"}],"subject":[],"published":{"date-parts":[[2023,3,20]]}}}