Effect of Entonox for pain management in labor

A systematic review and meta-analysis of randomized controlled trials

Authors

  • Morteza Ghojazadeh Associate Professor, Research Center for Evidence Based Medicine (RCEBM), Tabriz University of Medical Sciences, Tabriz, Iran

Keywords:

Entonox, Pain relief, Vaginal delivery, Apgar, Satisfaction

Abstract

Background and aim: Entonox was one of the important methods for pain management in the delivery process. In previous years some studies have assessed the effect of this method in Iran. In this regard, the aim of this study was to systematically review studies addressing the effect of Entonox for pain management in labor. Methods: This systematic review and meta-analysis study was conducted in 2016. The required data was collected using keywords such as ”Entonox”, “nitrous oxide”, ”vaginal delivery”, ”pain relief”, “obstetric”, “labor pain”, and “labor analgesia”, from databases including Google scholar, PubMed, Science Direct, Magiran, SID, and Scopus, and hand-searching of related and valid journals and references of articles. Articles published from 2000 to 2016 were searched. To conduct meta-analysis, CMA:2 (Comprehensive Meta-analysis) was used. Results: Finally, 14 articles were included in the study. Pain relief standard difference in mean between-groups was -1.01 (95% CI: -1.59 to -0.43, Q=148.5, df=8, p=0.02, I2=76) this difference was significant (p<0.05). The overall Apgar score standard difference in mean between-groups (Entonox vs. comparison) was 0.12 (95% CI: 0.01 to 0.23, Q=109.4, df=16, p=0.00, I2=85.3) this difference was significant (p<0.05). The results of mothers’ satisfaction rate show that mothers in Entonox group has a high level of satisfaction rate. Conclusion: According to results of studies published in Iran, it seems that Entonox is an effective method for pain relief in vaginal delivery, as well as for improving infant Apgar score and mothers’ satisfaction rate. Pain relief through Entonox can be used as a strategy for cesarean section reduction plan in Iran.

References

Page L. The new midwifery science and sensitivity in practice. London: Churchill Livingstone; 2000.

David H, Norman J. Gynecology illustrated. London: Churchill Livingstone Co; 2000.

Cunningham F, Leveno K, Bloom S, Fauser J, Zwirner M. Williams Obstetrics. New York: Graw-Hill;

Azami-Aghdash S, Ghojazadeh M, Dehdilani N, Mohammadi M, Asl Amin Abad R. Prevalence and causes

of cesarean section in Iran: Systematic review and meta-analysis. Iranian Journal of Public Health. 2014;

(5): 545-55. PMID: 26060756.

Castro TV, Franceschini SA, Poli-Neto O, Ferriani RA, Silva de Sa MF, Vieira CS. Effect of intracervical

anesthesia on pain associated with the insertion of the levonorgestrel-releasing intrauterine system in

women without previous vaginal delivery: a RCT. Human reproduction (Oxford, England). 2014; 29(11):

-45. doi: 10.1093/humrep/deu233. PMID: 25240012.

Kargar R, Aghazadeh-Nainie A, Khoddami-Vishteh HR. Comparison of the Effects of Lidocaine Prilocaine

Cream (EMLA) and Lidocaine Injection on Reduction of Perineal Pain During Perineum Repair in Normal

Vaginal Delivery. Journal of family & reproductive health. 2016; 10(1): 21-6. PMID: 27385970

Morais I, Lemos A, Katz L, Melo LF, Maciel MM, Amorim MM. Perineal Pain Management with

Cryotherapy after Vaginal Delivery: A Randomized Clinical Trial. Rev Bras Ginecol Obstet. 2016; 38(7):

-32. doi: 10.1055/s-0036-1584941. PMID: 27427867.

Hashizume M, Shimoda T, Sasaki S, Kunii O, Caypil W, Dauletbaev D, et al. Anaemia in relation to low

bioavailability of dietary iron among school-aged children in the Aral Sea region, Kazakhstan. Int J Food

Sci Nutr. 2004; 55(1): 37-43. doi: 10.1080/09637480310001642466. PMID: 14630590.

Tournaire M. Alternative approaches to pain relief during labor and delivery. Advances in experimental

medicine and biology. 2004; 546: 193-206. PMID: 15584375.

Borup L, Wurlitzer W, Hedegaard M, Kesmodel US, Hvidman L. Acupuncture as pain relief during

delivery: a randomized controlled trial. Birth (Berkeley, Calif). 2009; 36(1): 5-12. doi: 10.1111/j.1523- 536X.2008.00290.x. PMID: 19278378.

Leppert W, Krajnik M, Wordliczek J. Delivery systems of opioid analgesics for pain relief: a review.

Current pharmaceutical design. 2013; 19(41): 7271-93. PMID: 23489205.

Patel D, Naik S, Chuttani K, Mathur R, Mishra AK, Misra A. Intranasal delivery of cyclobenzaprine

hydrochloride-loaded thiolated chitosan nanoparticles for pain relief. Journal of drug targeting. 2013; 21(8):

-69. doi: 10.3109/1061186X.2013.818676. PMID: 23879335.

Simavli S, Kaygusuz I, Gumus I, Usluogullari B, Yildirim M, Kafali H. Effect of music therapy during

vaginal delivery on postpartum pain relief and mental health. Journal of affective disorders. 2014; 156:

-9. doi: 10.1016/j.jad.2013.12.027. PMID: 24411681.

Singer J, Jank A, Amara S, Stepan PD, Kaisers U, Hoehne C. Efficacy and Effects of Parenteral Pethidine

or Meptazinol and Regional Analgesia for Pain Relief during Delivery. A Comparative Observational

Study. Geburtshilfe Frauenheilkd. 2016; 76(9): 964-71. doi: 10.1055/s-0042-111009. PMID: 27681521.

Xie J, Xiao D, Zhao J, Hu N, Bao Q, Jiang L, et al. Mesoporous Silica Particles as a Multifunctional

Delivery System for Pain Relief in Experimental Neuropathy. Advanced healthcare materials. 2016; 5(10):

-21. doi: 10.1002/adhm.201500996. PMID: 27028159.

Clyburn P. The use of Entonox for labour pain should be abandoned. Int J Obstet Anesth. 2001; 10(1): 27- 9. doi: 10.1054/ijoa.2000.0821. PMID: 15321648.

Lyons A. How to ... administer Entonox. Midwives. 2011; 14(2): 24. PMID: 24888000

Najafi TF, Bahri N, Ebrahimipour H, Najar AV, Taleghani YM. Risk Assessment of Using Entonox for the

Relief of Labor Pain: A Healthcare Failure Modes and Effects Analysis Approach. Electron physician.

; 8(3): 2150-9. doi: 10.19082/2150. PMID: 27123224.

Varposhti MR, Ahmadi N, Masoodifar M, Shahshahan Z, Tabatabaie MH. Comparison of remifentanil:

Entonox with Entonox alone in labor analgesia. Advanced biomedical research. 2013; 2: 87. doi:

4103/2277-9175.122511. PMID: 24524033.

Yeo ST, Holdcroft A, Yentis SM, Stewart A, Bassett P. Analgesia with sevoflurane during labour: ii.

Sevoflurane compared with Entonox for labour analgesia. Br J Anaesth. 2007; 98(1): 110-5. doi:

1093/bja/ael327. PMID: 17158129.

Agah J, Baghani R, Safiabadi Tali SH, Tabarraei Y. Effects of continuous use of Entonox in comparison

with intermittent method on obstetric outcomes: a randomized clinical trial. Journal of pregnancy. 2014;

: 245907. doi: 10.1155/2014/245907. PMID: 25525519.

Esfandiari M, karimi S. Effectiveness of Entonox on Severity of Labor Pain in Women Referred to

Maternity Ward of Imam Reza hospital Kermanshah 2007. sjimu. 2009; 17(1): 25-30.

Moher D, Liberati A, Tetzlaff J, Altman DG. Preferred reporting items for systematic reviews and meta- analyses: the PRISMA statement. Ann Intern Med. 2009; 151(4): 264-9. doi: 10.7326/0003-4819-151-4- 200908180-00135. PMID: 19622511.

Moher D, Liberati A, Tetzlaff J, Altman DG. Preferred reporting items for systematic reviews and meta- analyses: the PRISMA statement. PLoS Med. 2009; 6(7):21. doi: 10.1371/journal.pmed.1000097. PMID:

Moher D, Liberati A, Tetzlaff J, Altman DG. Preferred reporting items for systematic reviews and meta- analyses: the PRISMA Statement. Open Med. 2009; 3(3): 21. PMID: 21603045.

Carstoniu J, Levytam S, Norman P, Daley D, Katz Y, Sandler A. Nitrous Oxide in early labor. Safety and

analgesic efficacy assessed by a double- blind, placebo- controlled study. Anesthesiology 1994; 80(1): 30- 5. PMID: 8291726.

Soyannwo O. Self-administered Entonox in labour: report of experience in Ibadan. Afr J Med Neel Sci.

; 14(1-2): 95-8. PMID: 2994447.

Rosen M. Relief of labor pain. Am J Obstet Gynecol. 2004: 110-21.

Rooks JP. Labor pain management other than neuraxial: what do we know and where do we go next? Birth

(Berkeley, Calif). 2012; 39(4): 318-22. doi: 10.1111/birt.12009. PMID: 23281953.

Volmanen E. Comparsion of Remifentanil and Nitro oxide in labor. Actaa Anaesthesiological Scandinavia

Journal. 2005; 49(4): 453-8. doi: 10.1111/j.1399-6576.2005.00639.x. PMID: 15777291.

Dunen I, Rooks J. Use of nitrous oxide in midwifery practice – complementary, synergistic, and needed in

the united states. Journal of Midwifery & Women's Health. 2007; 52(3): 186-9. doi:

1016/j.jmwh.2007.02.017. PMID: 17467584.

Rosen M. Nitrous oxide for relief of labor pain: a systematic review. Am J Obstet Gynecol. 2002; 186:

S110-260. doi: 10.1016/S0002-9378(02)70186-5. PMID: 12011877.

Rezaeipour A, Idenloo F, Khakbazan Z, Kazemnejad K. The effects of Entonox on implication of painless

labor and delivery satisfaction rate among pregnant women. Hayat. 2008; 13(4): 45-58.

Teimoori B, Sakhavar N, Mirteimoori M, Narouie B, Ghasemi-rad M. Nitrous Oxide versus Pethidine with

Promethasine for Reducing Labor Pain. Gynecol Obstetric 2011; 1(1): 1-4. doi: 10.4172/2161- 0932.1000106.

Pasha H, Basirat Z, Hajahmadi M, Bakhtiari A, Faramarzi M, Salmalian H. Maternal Expectations and

Experiences of Labor Analgesia With Nitrous Oxide. Iran Red Cres Med J. 2012; 14(12): 792-7. doi:

5812/ircmj.3470. PMID: 23483128.

Najefian M, Cheraghi M, Pourmehdi Z, Nejad AD. The effect of nitrous oxide (ENTONOX) on labour pain

relief during delivery stages. International Journal of Pharmacy & Therapeutics. 2013; 4: 242-6. doi:

18203/2320-1770.

Khadem N, Zirak N, Soltani G, Sahebdelfar N, Sepehri Shamloo A, Ebrahimzadeh S. Comparison of

Epidural versus Entonox for Labor Analgesia in Nulliparous Women. Journal of Surgery and Trauma.

; 1(1): 1-5.

Mobaraki N, Yousefian M, Seifi S, Sakaki M. A Randomized Controlled Trial Comparing Use of Enthonox

With Pethidine for Pain Relief in Primigravid Women During the Active Phase of Labor. Anesth Pain Med.

; 6(4): e37420. doi: 10.5812/aapm.37420. PMID: 27843776.

Salehian T, Safdari F, Jahantighi S. The Effect of Entonox on Labor Pain and Outcome of Delivery in

Primiparous in Iranshahr, Iran (2009). Journal Of Research Development in Nursing & Midwifery. 2010;

(1): 1-9.

Yazdi Moghaddam H, Rahnamai Rahsepar F, Heidari A. Studying the Effect of Entonox Gas on the

APGAR of the Neonates. Journal of Rafsanjan University of Medical Sciences. 2011; 10(3): 165-74.

Mohammad Jaafari R, Torabzadeh Bafghi V, Torabzadeh Bafghi A. The Effect of Entonox gas Inhalation

on the Duration of Active Phase of Labor and Outcome of Delivery. Jundishapur Sci Med J. 2013; 12(1):

-9. 42) Jafarzadeh L, Shabanian S, Jafari F, Gangi F. The effect of Entonox on severity of pain and mother

hemodynamic and fetus apgar in natural vaginal delivery. J Sharekord Univ Med Sci. 2012; 14(3): 92-9.

Saghiri M, Sattarzadeh N, Tabrizi N, Pezeshki ZA. A Comparative Study on the Severity of Labor Pain

with or without Entonox and it's effects on the new-borns of Primiparas. Journal of Ardabil University of

Medical Sciences. 2008; 8(1): 62-7.

Masoudi M, Akbari S. The comparison of Entonox and warm water effect on labor pain. Yafte. 2011;

(2): 25-32.

Talebi H, Nourozi A, Jamilian M, Baharfar N, Eghtesadi-Araghi P. Entonox for labor pain: A randomized

placebo controlled trial. Pak J Biol Sci. 2009; 12(17): 1217-21. PMID: 19943458

Published

2022-02-12