Karabayirh 2003

Methods	N; B; N; N; Y; Y
Participants	62 adults; 36 female; middle ear; ASA1,2; 18‐60 (mean 34); exc' CNS/ear disease, motion sickness/PONV
Interventions	Induction AND postoperative Either: NO TREATMENT or DEXAMETHASONE 5mg i.v. or ONDANSETRON 8mg then 50% O2 + 50% N2O; or NO TREATMENT then 75% O2 + 25% N2O
Outcomes	Nausea; vomiting; rescue antiemetic. Postop 0‐6; 6‐24 hours.
Notes	Rescue antiemetic only 6‐24 hours. Nausea commonest 6‐24 hours. Male/female incidences not reported. No side effects. Unclear how retching categorized or if vomiters nauseated or categorized once or twice.
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Unclear risk	B ‐ Unclear