Vilas Boas 2011.

Methods	RCT, parallel design, Hospital Municipal Odilon Behrens, Brazil Sample size: details on sample size calculation not mentioned
Participants	Total: 29 adult patients, ASA I/II (female; male) Age [mean (standard deviation)]: mannitol group: 44 (3.34) years; HIS group: 49.5 (4.52) years Gender (male/female): mannitol group: 8/9; HIS group: 6/6 Inclusion: patients undergoing elective craniotomy and cerebral aneurysm clipping, arteriovenous malformations or cerebral tumours (4 in mannitol group and 5 in HIS group) Exclusion: age < 21 years, initial serum Na < 130 or > 150 mEq/L, metabolic disorders, treatment with hyperosmotic solution up to 24 hours before surgery or history of past heart or renal failure
Interventions	HIS 360 mL/h for 20 minutes Control: 20% mannitol at 750 mL/h for 20 minutes
Outcomes	Brain bulk
Notes	4‐point scale: 1 = perfect relaxation; 2 = satisfactory relaxation; 3 = firm brain; 4 = swollen brain
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No appropriate information provided
Allocation concealment (selection bias)	Unclear risk	No appropriate information provided
Blinding of participants and personnel (performance bias) All outcomes	High risk	The anaesthetist was not blinded
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "Cerebral relaxation was evaluated by the same surgeon who was blind to the hyperosmolar therapy used….." Comment: probably done
Incomplete outcome data (attrition bias) All outcomes	Low risk	Data on all participants reported
Selective reporting (reporting bias)	Low risk	All outcomes mentioned in the methodology have been reported
Other bias	High risk	Communication: "Isoncotic Hypertonic Solution was a donation by the Fresenius Kabi AG"