Caesarean section is a commonly performed operation for the birth of a baby when difficulties arise either for the mother or for the baby. Women may be either awake for the procedure (regional anaesthesia) or asleep (general anaesthesia). Nausea and vomiting are common and distressing symptoms, which can occur during the procedure if the woman is awake or they can also occur after the procedure. Low blood pressure and some of the medications administered during the procedure may contribute to the nausea and vomiting.
A wide range of medications are commonly used either to reduce the chance of symptoms occurring, or are given as a treatment if symptoms do occur. In addition, a number of non-drug approaches have been tried such as using acupuncture or acupressure; giving extra oxygen; or giving extra intravenous fluids. We aimed to study the effectiveness of the various treatments to reduce the occurrence of nausea and vomiting during elective or emergency caesarean section using regional anaesthesia. We found 41 studies (involving 5046 women) that met our inclusion criteria and provided data which we could analyse. These were mainly small studies of unclear or poor quality.
Nevertheless, we found that many drugs, such as 5-HT3 antagonists (e.g. ondansetron), dopamine antagonists (e.g. metoclopramide, droperidol) and sedatives (mainly propofol) were effective in reducing the occurrence of nausea and vomiting either during surgery under regional anaesthesia or afterwards. Other effective interventions for some nausea and vomiting included corticosteroids (e.g. dexamethasone), antihistamines (e.g. cyclizine) and anticholinergics (e.g. scopolamine). In addition, acupressure was effective in reducing some nausea but not vomiting.
Few studies assessed the possible side effects such as headaches, dizziness, low blood pressure, skin rashes and breathing difficulties.
In addition to this review, there will be two further reviews on nausea and vomiting at caesarean section. The first will look at interventions given to reduce nausea and vomiting after general anaesthesia (as opposed to regional anaesthesia). The second will explore interventions given as a treatment to women who do suffer nausea and vomiting during regional anaesthesia.