One or both of the following was most predictive of post-operative nausea and vomiting requiring an observational stay (odds ratio 5.21):
(1) history of previous post-operative nausea and vomiting
(2) history of motion sickness
Other factors associated with post-operative nausea and vomiting in multivariate analysis:
(1) age > 50 years (odds ratio 1.56)
(2) induction agent (volatile agents vs thiopental; odds ratio 2.14)
(3) maintenance inhalational agent (desflurane vs isoflurane, odds ratio 2.31)
Other factors associated with a prolonged hospital stay:
(1) surgery in the afternoon
The severity of disease did not correlate with length of stay.
Any patient undergoing tympanomastoidectomy may require a 23 hour observation stay, but it is more likely if one or more risk factors (for PONV, late day surgery) is present.
