Pain relieving gas is often used to relieve labour pain. Entonox is a mixture of oxygen and nitrous oxide (laughing gas). It is designed to provide as good a pain relief as possible without causing undue sleepiness. The gas works quickly, but takes about 30 to 45 seconds to have an effect.
To gain maximum benefit you need to start breathing it as soon as you feel a contraction start. This means the maximum action is being achieved at the height of the contraction.
Entonox can be used throughout both early labour and the delivery of your baby. Entonox crosses the placenta but is not known to have any effect on your baby. The higher concentration of oxygen may help your baby.
Some mothers feel light-headed during use. Occasionally nausea can be experienced, as can tiredness. Some mothers complain of a dry mouth, so you may wish to have a glass of water to sip, or small ice cubes to suck.
You may experience a tingling in your fingers. This is due to overbreathing. Your midwife will know when you are doing this and remind you of your breathing exercises (sigh out slowly) and this will automatically lead to rhythmic breathing.
Entonox only works when you breathe it in, so its effects wear off very quickly once you stop breathing it, normally within a minute.
Gas mixtures will give help to relieve pain but will not remove it completely. The best use is to cope with a short periods of pain, such as the time immediately before giving birth.
Pain Killing Injections
The three painkilling drugs available at the Jessop Hospital are Diamorphine, Pethidine and Meptazinol. They are used on your request to relieve pain during labour. They are administered with an injection into the muscle of the thigh or buttock. The drugs can sometimes be given into the bloodstream directly for a faster effect.
There are some devices which can be programmed to allow you to administer the drug yourself (Patient Controlled Analgesia-PCA). These are commonly used for postoperative pain, but are occasionally suitable for pain relief in labour.
Pressing a button releases a controlled amount of drug into the blood. Doses can be added until you are comfortable.
These drugs are available to all expectant mothers on request, but individual circumstances are taken into account. The dose given broadly depends upon body weight.
You may have more than one dose during labour. Monitoring of the baby's heart rate is done at the midwives' discretion (if there are no other reasons to monitor it). Side effects of these drugs are drowsiness, nausea and vomiting.
They can slow your breathing down if you have too much. If given close to the birth of your baby, they can slow down the baby's breathing and make him or her sleepy.