Comparison of nausea

• Research type

  Research Study

• Full title

  A comparison of nausea with two routine ways of managing low blood pressure after delivery of the baby during spinal anaesthesia for Caesarean section.

• IRAS ID

  20107

• Eudract number

  2009-013543-11

• ISRCTN Number

  N/A

• Clinicaltrials.gov Identifier

  N/A

• Research summary

  Spinal anaesthesia is the most commonly used anaesthetic for elective Caesarean section in the UK. It is safe and effective, but nausea occurs in up to 80% of cases. Nausea is strongly associated with low blood pressure (hypotension) and reducing hypotension before delivery of the baby reduces nausea. Before delivery of the baby, the supine position of the mother during surgery causes the pregnant uterus to occlude the inferior vena cava (caval occlusion), which reduces the return of blood to the heart, causing hypotension. The hypotension is compounded by spinal anaesthesia, which causes extensive blockade of the sympathetic nervous system (the part of the nervous system responsible for maintaining blood pressure). Phenylephrine, a drug that mimics the sympathetic nervous system, is usually required to treat hypotension before delivery of the baby. Nausea can occur both before and after delivery of the baby. The nausea that occurs before delivery is most likely to be associated with hypotension. Delivery of the baby relieves caval compression, which reduces hypotension. Between delivery and the end of surgery, factors other than hypotension probably contribute significantly to nausea. The aim of this study is to find out if a prophylactic phenylephrine infusion reduces maternal nausea after delivery of the baby. This double-blind, randomised, placebo-controlled trial will study low risk women with a singleton pregnancy scheduled for elective Caesarean section. All will be given a prophylactic infusion of phenylephrine until the delivery of the baby. Following delivery, half will continue to receive a prophylactic phenylephrine infusion, but half will receive a saline infusion instead. For all patients, any episodes of hypotension will be rapidly treated with boluses of phenylephrine. The study will last until the end of the operation. We will ask the women at regular intervals whether they have any nausea.

• REC name

  North East - Tyne & Wear South Research Ethics Committee

• REC reference

  09/H0904/41

• Date of REC Opinion

  19 Oct 2009

• REC opinion

  Further Information Favourable Opinion