The main use of gas in labour is for pain relief at the request of the woman. It can also be used for other reasons at the suggestion of the caregiver. The following are the main reasons gas could be used in the labour.
Pain relief
Anxious or concerned
Anterior lip
Medical interventions
Pain relief
As far as using medical forms of pain relief for labour, gas tends to 'the first line of action' for many caregivers. This is because it is easily accessible, easy to administer, reversible if the woman does not like it, (as the effects are removed within a couple of minutes after stopping) and has the least amount of side effects for the mother and baby.
Gas can be particularly helpful for the transitional phase of first stage, as the woman's natural forms of pain relief possibly start to lessen in effectiveness, especially if the woman is not keen to take on a narcotic injection or an epidural. Gas tends to be encouraged if the woman is considered too advanced in her labour to have a narcotic injection or an epidural (say at the end of the 1st stage or in the pushing phase), but may be used as a 'stop gap' while the women is waiting for her narcotic injection or epidural to be administered and take effect.
Gas can also be used if the epidural is wearing off and the woman feels she needs some extra pain relief, but still wants to feel 'what is happening' in the pushing phase of her labour.
If the woman is in prelabour or the early 1st phase of labour, it may be suggested that she delay having gas (or have a narcotic injection instead), as long term use of the gas (more than a couple of hours) can be physically tiring for the woman, leading to exhaustion.
The caregiver may discourage the use of gas during the pushing phase if the woman appears not to be pushing effectively. This is usually because she is concentrating on breathing in adequate amounts of gas to relieve the pain, rather than exerting a pushing effort with the contraction.