The use of 0.25% isoflurane premixed in 50% nitrous oxide and oxygen for pain relief in labour

John A S Ross, M E Tunstall, D M Campbell, J S Lemon

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

The addition of 0.25% isoflurane to 50% nitrous oxide in oxygen provides more effective pain relief in labour than 50% nitrous oxide alone. This study was carried out to determine whether self-administration by demand valve of 0.25% isoflurane in 50% nitrous oxide in oxygen premixed in cylinders at 13.7 MPa (IN2O) was practical and safe during labour. Two hundred and twenty-one mothers used INO in labour after 50% nitrous oxide had become inadequate for pain relief. Data on IN2O use was recorded during labour and details of the course of labour and opioid usage were taken from the clinical notes. The duration of IN2O use was 0.1-12:35h (median 2.3). Thirty-two mothers (14.5%) required an epidural and intolerance to IN2O was seen in a maximum of 17 cases (7.7%). One hundred and twenty-six cases were primiparous and 93 parous with 151 deliveries being spontaneous and 70 interventional, of which 12 were by Caesarean section. Maternal blood loss was 20-1500 ml (median 200 ml). Apgar scores at 1 and 5 min were unaffected by IN2O use although a positive correlation was found between the use of opioids and the number of neonates with a 1-min score below 8 and the number requiring resuscitation; Six neonates had an Apgar score below 8 at 5 min, but their condition was adequately explained by factors other than the sedative technique used. Self-administered IN2O was found to be a safe and practical technique for sedation in labour when 50% nitrous oxide alone had become inadequate.

Original languageEnglish
Pages (from-to)1166-1172
Number of pages7
JournalAnaesthesia
Volume54
Issue number12
DOIs
Publication statusPublished - 1 Dec 1999

Keywords

  • Adolescent
  • Adult
  • Analgesia, Obstetrical
  • Analgesia, Patient-Controlled
  • Anesthetics, Combined
  • Anesthetics, Inhalation
  • Apgar Score
  • Delivery, Obstetric
  • Drug Administration Schedule
  • Female
  • Humans
  • Isoflurane
  • Nitrous Oxide
  • Oxygen
  • Postpartum Hemorrhage
  • Pregnancy
  • Resuscitation

Cite this

The use of 0.25% isoflurane premixed in 50% nitrous oxide and oxygen for pain relief in labour. / Ross, John A S; Tunstall, M E ; Campbell, D M ; Lemon, J S .

In: Anaesthesia, Vol. 54, No. 12, 01.12.1999, p. 1166-1172.

Research output: Contribution to journalArticle

Ross, John A S ; Tunstall, M E ; Campbell, D M ; Lemon, J S . / The use of 0.25% isoflurane premixed in 50% nitrous oxide and oxygen for pain relief in labour. In: Anaesthesia. 1999 ; Vol. 54, No. 12. pp. 1166-1172.
@article{7c4ce736969e4bfe9d2e9f958d87749e,
title = "The use of 0.25{\%} isoflurane premixed in 50{\%} nitrous oxide and oxygen for pain relief in labour",
abstract = "The addition of 0.25{\%} isoflurane to 50{\%} nitrous oxide in oxygen provides more effective pain relief in labour than 50{\%} nitrous oxide alone. This study was carried out to determine whether self-administration by demand valve of 0.25{\%} isoflurane in 50{\%} nitrous oxide in oxygen premixed in cylinders at 13.7 MPa (IN2O) was practical and safe during labour. Two hundred and twenty-one mothers used INO in labour after 50{\%} nitrous oxide had become inadequate for pain relief. Data on IN2O use was recorded during labour and details of the course of labour and opioid usage were taken from the clinical notes. The duration of IN2O use was 0.1-12:35h (median 2.3). Thirty-two mothers (14.5{\%}) required an epidural and intolerance to IN2O was seen in a maximum of 17 cases (7.7{\%}). One hundred and twenty-six cases were primiparous and 93 parous with 151 deliveries being spontaneous and 70 interventional, of which 12 were by Caesarean section. Maternal blood loss was 20-1500 ml (median 200 ml). Apgar scores at 1 and 5 min were unaffected by IN2O use although a positive correlation was found between the use of opioids and the number of neonates with a 1-min score below 8 and the number requiring resuscitation; Six neonates had an Apgar score below 8 at 5 min, but their condition was adequately explained by factors other than the sedative technique used. Self-administered IN2O was found to be a safe and practical technique for sedation in labour when 50{\%} nitrous oxide alone had become inadequate.",
keywords = "Adolescent, Adult, Analgesia, Obstetrical, Analgesia, Patient-Controlled, Anesthetics, Combined, Anesthetics, Inhalation, Apgar Score, Delivery, Obstetric, Drug Administration Schedule, Female, Humans, Isoflurane, Nitrous Oxide, Oxygen, Postpartum Hemorrhage, Pregnancy, Resuscitation",
author = "Ross, {John A S} and Tunstall, {M E} and Campbell, {D M} and Lemon, {J S}",
note = "Medline is the source for the MeSH terms of this document.",
year = "1999",
month = "12",
day = "1",
doi = "10.1046/j.1365-2044.1999.01130.x",
language = "English",
volume = "54",
pages = "1166--1172",
journal = "Anaesthesia",
issn = "0003-2409",
publisher = "Wiley-Blackwell",
number = "12",

}

TY - JOUR

T1 - The use of 0.25% isoflurane premixed in 50% nitrous oxide and oxygen for pain relief in labour

AU - Ross, John A S

AU - Tunstall, M E

AU - Campbell, D M

AU - Lemon, J S

N1 - Medline is the source for the MeSH terms of this document.

PY - 1999/12/1

Y1 - 1999/12/1

N2 - The addition of 0.25% isoflurane to 50% nitrous oxide in oxygen provides more effective pain relief in labour than 50% nitrous oxide alone. This study was carried out to determine whether self-administration by demand valve of 0.25% isoflurane in 50% nitrous oxide in oxygen premixed in cylinders at 13.7 MPa (IN2O) was practical and safe during labour. Two hundred and twenty-one mothers used INO in labour after 50% nitrous oxide had become inadequate for pain relief. Data on IN2O use was recorded during labour and details of the course of labour and opioid usage were taken from the clinical notes. The duration of IN2O use was 0.1-12:35h (median 2.3). Thirty-two mothers (14.5%) required an epidural and intolerance to IN2O was seen in a maximum of 17 cases (7.7%). One hundred and twenty-six cases were primiparous and 93 parous with 151 deliveries being spontaneous and 70 interventional, of which 12 were by Caesarean section. Maternal blood loss was 20-1500 ml (median 200 ml). Apgar scores at 1 and 5 min were unaffected by IN2O use although a positive correlation was found between the use of opioids and the number of neonates with a 1-min score below 8 and the number requiring resuscitation; Six neonates had an Apgar score below 8 at 5 min, but their condition was adequately explained by factors other than the sedative technique used. Self-administered IN2O was found to be a safe and practical technique for sedation in labour when 50% nitrous oxide alone had become inadequate.

AB - The addition of 0.25% isoflurane to 50% nitrous oxide in oxygen provides more effective pain relief in labour than 50% nitrous oxide alone. This study was carried out to determine whether self-administration by demand valve of 0.25% isoflurane in 50% nitrous oxide in oxygen premixed in cylinders at 13.7 MPa (IN2O) was practical and safe during labour. Two hundred and twenty-one mothers used INO in labour after 50% nitrous oxide had become inadequate for pain relief. Data on IN2O use was recorded during labour and details of the course of labour and opioid usage were taken from the clinical notes. The duration of IN2O use was 0.1-12:35h (median 2.3). Thirty-two mothers (14.5%) required an epidural and intolerance to IN2O was seen in a maximum of 17 cases (7.7%). One hundred and twenty-six cases were primiparous and 93 parous with 151 deliveries being spontaneous and 70 interventional, of which 12 were by Caesarean section. Maternal blood loss was 20-1500 ml (median 200 ml). Apgar scores at 1 and 5 min were unaffected by IN2O use although a positive correlation was found between the use of opioids and the number of neonates with a 1-min score below 8 and the number requiring resuscitation; Six neonates had an Apgar score below 8 at 5 min, but their condition was adequately explained by factors other than the sedative technique used. Self-administered IN2O was found to be a safe and practical technique for sedation in labour when 50% nitrous oxide alone had become inadequate.

KW - Adolescent

KW - Adult

KW - Analgesia, Obstetrical

KW - Analgesia, Patient-Controlled

KW - Anesthetics, Combined

KW - Anesthetics, Inhalation

KW - Apgar Score

KW - Delivery, Obstetric

KW - Drug Administration Schedule

KW - Female

KW - Humans

KW - Isoflurane

KW - Nitrous Oxide

KW - Oxygen

KW - Postpartum Hemorrhage

KW - Pregnancy

KW - Resuscitation

UR - http://www.scopus.com/inward/record.url?scp=0032705174&partnerID=8YFLogxK

U2 - 10.1046/j.1365-2044.1999.01130.x

DO - 10.1046/j.1365-2044.1999.01130.x

M3 - Article

VL - 54

SP - 1166

EP - 1172

JO - Anaesthesia

JF - Anaesthesia

SN - 0003-2409

IS - 12

ER -