Use safest or cheapest drug first for PONV
Use the safest or least expensive antiemetic intervention first for postoperative nausea and vomiting, says an international panel of anaesthetists reporting the findings of a multicentre trial.
They looked at six interventions to prevent postoperative nausea and
vomiting (PONV) in over 5,000 patients. Unlike previous studies, their
trial evaluates all the major pharmacological interventions
simultaneously. The treatment options, of up to three interventions,
allowed 64 possible combinations of therapy.
The researchers conclude that the antiemetics tested (ondansetron, dexamethasone
and droperidol) appear to have similar efficacy, with a risk reduction
of PONV of about 26 per cent. They note that ondansetron is considered
more expensive than the other two agents, and there are safety concerns
with droperidol. (This agent is now unavailable because of concern over
cardiac side effects in psychiatric usage. However, a commentator on
this study notes that these effects do not appear to be linked with antiemetic
doses.) “This makes dexamethasone at a dose of 4mg an attractive
first line agent for prophylaxis against PONV,” they say.
Their analysis also found that substituting propofol for a volatile anaesthetic
reduced the risk of PONV by about 19 per cent, and using nitrogen in
place of nitrous oxide by 12 per cent. Combining these strategies reduced
risk by about as much as any single antiemetic. In contrast remifentanil
used instead of fentanyl did not reduce risk.
Combining interventions provided progressively less benefit and would
increase costs and the likelihood of adverse effects, the researchers
note. They suggest using dexamethasone and total intravenous anaesthesia
as first- and second-line interventions, reserving serotonin antagonists
such as ondansetron as a rescue treatment (New England Journal of
Medicine 2004;350:2441). |
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