Hassanein 2015.

Study characteristics
Methods	RCT
Participants	Inclusion criteria: Women elective CS under spinal, ASA 1 or 2, 20–40 years N = 135 women Excluson criteria:
Interventions	Group 1: sedative (Comparison 6) Ketamine 0.4 mg/kg in 5 mL normal saline IV slowly after anaesthesia and before surgery N = 45 Group 2: steroids (Comparison 3) Dexamethasone 8 mg in 5 mL normal saline IV slowly after anaesthesia and before surgery N = 45 Group 3: placebo 5 mL normal saline. IV slowly after anaesthesia and before surgery N = 45
Outcomes	Intra‐operative nausea and vomiting, sedation scores
Notes	Setting: Al‐Minia University, Egypt. Dates: not reported. Funding source: not reported. Declaration of interest: not reported. In some cases, but not all, tubal ligation was performed. These were not analysed separately.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "randomly allocated"
Allocation concealment (selection bias)	Unclear risk	Unspecified
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Syringes were given by the second anaesthetist to the anaesthetist who was unaware of the content of the syringe
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Nausea, retching and vomiting episodes were recorded by an anaesthetist who was blinded to the drug administered
Incomplete outcome data (attrition bias) All outcomes	Low risk	3 patients excluded due to inadequate spinal anaesthesia
Selective reporting (reporting bias)	Unclear risk	We were unable to assess the study protocol
Other bias	High risk	Some patients had tubal ligation as well, number unspecified