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This is a plain English summary of an original research article. The views expressed are those of the author(s) and reviewer(s) at the time of publication.

A single dose of dexamethasone given at the time of anaesthesia for bowel surgery reduced vomiting in the next 24 hours, with no increase in complications. Thirteen people need to be treated to prevent one extra episode of vomiting.

Dexamethasone (a steroid) is one of several drugs recommended for patients at moderate and high risk of postoperative nausea and vomiting. It isn’t widely used in bowel surgery.

In this large UK-based trial, treating eight people also prevented one person requesting additional anti-sickness drugs. There was no increase in adverse events, and patients given dexamethasone returned to eating quicker.

Postoperative nausea and vomiting can delay recovery, so this finding has the potential to improve outcomes for patients and reduce NHS costs.

Why was this study needed?

Postoperative nausea and vomiting affects more than 30% of patients after surgery. It can result in delayed recovery and prolonged hospital stays, increasing overall health care costs. Preventing nausea and vomiting is particularly important for patients having bowel surgery, because they often have poor nutrition before their operations.

Dexamethasone is already used to prevent nausea and vomiting after operations. However, its effectiveness in patients having bowel surgery hasn’t been assessed and it isn’t widely used in the UK for these patients. There are also concerns that steroids could have adverse effects in this patient group, such as infections and increasing blood sugar. This study aimed to see if dexamethasone could improve the postoperative recovery of people having bowel surgery without increasing risk of complications.

What did this study do?

DREAMS was a randomised controlled trial that compared a single 8mg intravenous dose of dexamethasone given at the start of anaesthesia with standard care. It included 1350 adults undergoing elective open or laparoscopic (keyhole) small or large bowel surgery at 45 hospitals in the UK. The majority were having bowel resection. Exclusions included patients with acute bowel obstruction, stomach ulcer, diabetes, glaucoma and currently taking steroids.

All patients received a routine antiemetic (anti-sickness drug) other than dexamethasone as part of standard care. Postoperative anti-emetics were given at patient request.

Anaesthetists could not be blinded to treatment allocation, and used additional anti-emetics outside of protocol in 14% of patients, mostly in the standard care group. However, individuals making postoperative assessments were unaware of treatment group.

What did it find?

  • Fewer patients experienced vomiting (patient or doctor reported) within 24 hours of surgery in the dexamethasone group: 25.5% vs 33.2% with standard care (risk ratio [RR] 0.77, 95% confidence interval 0.65 to 0.92). This means that 13 patients would need treatment for one to benefit (95% CI 5 to 22). The difference between groups was not statistically significant 25 to 120 hours after surgery.
  • Postoperative anti-emetics were used by fewer people in the dexamethasone group up to three days after surgery. In the first 24 hours 39.3% requested anti-emetics versus 51.9% in the standard care group (RR 0.76, 95% CI 0.67 to 0.85). The respective proportions from 25 to 72 hours were 52.4% vs 62.9%. The number of doses and the number of anti-emetics were lower in the dexamethasone group. Giving dexamethasone to eight patients prevented one extra person needing anti-emetics within 24 hours (95% CI 5 to 14).
  • There were no differences in any adverse effects between the groups. These included infections, leaks of the bowel join (anastomosis) and abdominal abscesses. Thirty patients overall died, 1.9% of the dexamethasone group and 2.5% of the standard care group.
  • Most patients (96%) had started fluid by 24 hours, and among these more in the dexamethasone group had also started eating (62.3% vs 53.1%). There were no differences in length of hospital stay or quality of life scores.

What does current guidance say on this issue?

The Society for Ambulatory Anesthesiology has produced consensus guidelines for the management of postoperative nausea and vomiting. They recommend a prophylactic (preventative) dose of 4-5mg intravenous dexamethasone given at the time of anaesthesia induction for patients at increased risk of postoperative nausea and vomiting, except in patients with diabetes.

What are the implications?

This large trial gives confidence that a single 8mg dose of intravenous dexamethasone, given at induction of anaesthesia, is safe and effective for non-diabetic patients undergoing bowel surgery. It can reduce vomiting in the first 24 hours after surgery, without increasing short term adverse effects. Increased blood sugar levels, and the possibility of increased risk of cancer recurrence, remain a concern.

Quicker recovery for patients could reduce costs, though the length of hospital stay wasn’t affected in this trial. Poor bowel motility (ileus) was not specifically reported as an outcome, but those in the dexamethasone group did return more quickly to eating, which is promising.

Citation and Funding

DREAMS Trial Collaborators and West Midlands Research Collaborative. Dexamethasone versus standard treatment for postoperative nausea and vomiting in gastrointestinal surgery: randomised controlled trial (DREAMS Trial). BMJ. 2017;357:j1455.

This project was funded by the National Institute for Health Research (NIHR) Research for Patient Benefit programme (project number PB-PG-1111-26067).


Gan TJ, Diemunsch P, Habib AS, et al. Consensus Guidelines for the Management of Postoperative Nausea and Vomiting Anesth Analg. 2014;118(1):85-113.

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