Chewing gum for the treatment of postoperative nausea and vomiting

“No one dies of nausea, but it can seriously sap the will to live.” – Piscine Molitor Patel (Life of Pi)

 

Chewing gum for the treatment of postoperative nausea and vomiting: a pilot randomized controlled trial. Darvall JN, Handscombe M, Leslie K. Br J Anaesth. 2017 Jan;118(1):83-89. doi: 10.1093/bja/aew375.

This study attempted to demonstrate that chewing gum may be a valid alternative first line treatment for postoperative nausea and vomiting (PONV) when compared to intravenous ondansetron.

The trial’s design was to demonstrate non-inferiority which may go on to provide the foundation for a larger randomized controlled trial.

Chewing gum has previously been successfully incorporated into enhanced recovery packages of care and mechanistically has been postulated to reduce nausea and vomiting via the ‘sham feeding’ effect linked to vagal stimulation.

The authors comment that chewing gum may be beneficial due to it being a non-pharmacological agent, with near zero side effects that could be self-administered as a treatment for PONV in the postoperative care setting.

The study was conducted by the Department of Pain and Anaesthesia at the Royal Melbourne Hospital in 2016.  155 patients were assessed as eligible of which 94 were randomized. Intraoperative anaesthesia and intraoperative anti-emetics were protolised and patients were randomized pre-operatively.

The control arm (n = 46) had protocoled intravenous anti-emetics on the occurrence of PONV, the current institutions standard of care. The chewing gum trial arm (n = 48) had chewing gum administered as first line on occurrence of PONV with rescue intravenous anti-emetics available if required.

Primary outcome was full resolution of PONV post single dose of allocated intervention. Secondary outcomes included partial resolution of symptoms, recurrence of symptoms, and requisite for intravenous rescue anti emetics.

According to the authors, the results demonstrated that chewing gum was non-inferior to ondansetron (Symptoms resolution results of 75% and 39% respectively) for the treatment of PONV. Non-inferiority statistics demonstrated a p-value of 0.02.

Although this study provides full disclosure on all data and results are presented in a very detailed fashion, our department felt no substantial conclusions can be drawn from this paper due to the poor recruitment numbers.  This was on the basis that the majority of those patients who were randomized did not receive their allocated treatment. Additional criticism was of the author’s observed PONV rate at almost 30% despite protocolised prophylaxis intraoperatively.

Overall, a well presented but very limited data set which would require substantial expansion and evaluation prior to drawing any substantial conclusions as to the treatment effect of chewing gum in comparison to intravenous agents.

Summary by Dr Bryn Williams