Ohki 1997.

Methods	Blinding of randomization: yes Blinding of intervention: no (nurses prepared the medication) Complete follow up: yes Blinding of outcome: yes Randomized clinical trial, cross‐over design with pooled data Washout 48 hours before the study and 48 hours at crossover
Participants	Number of patients entered into the study: n=8 Mechanical ventilation Entry criteria: Birthweight < 1500 g, respiratory distress requiring mechanical ventilation for > 14 days, chest radiographic evidence of chronic lung disease, no administration of diuretics for at least 48 hour before the start of the study. Exclusion criteria: evidence of congenital malformations, patent ductus arteriosus, congenital heart disease, sepsis or pneumonia. Eight infants were randomized, 6 girls and 2 boys. Average birth weight was 798±225 g and gestational age 26.5±1.9 weeks. Six of 8 patients had received surfactant for RDS. At the time of study postnatal age was 32±15 days, postconceptional age 29.3±1.5 weeks, weight 807±236 g, peak pressure 20±7 cm H2O, ventilatory rate 20±7, FiO2 0.30±0.08, paO2 65.0±13.2 mm Hg and paCO2 50.5±4.5 mm Hg.
Interventions	Aerosolized furosemide versus placebo Patients were randomly allocated to receive either a single dose of aerosolized furosemide 2 mg/kg diluted in 3 ml of normal saline, followed after 48 hours by placebo, or vice versa.
Outcomes	Main outcome: static compliance, resistance and tidal volume. Furosemide administration was followed by a significant increase in compliance from 0.77±0.22 ml/cm/kg initially to 0.94±0.24 ml/m/kg after 1 hour and 0.92±0.18 after 2 hours; compliance did not change after placebo (corresponding values, 0.86±0.21 ml/cm/kg, 0.84±0.16 and 0.85±0.20 ml/cm/kg). Furosemide was also followed by an increase in tidal volume from 7.51±1.26 ml/kg to 9.71±1.70 after 1 hour and 9.59±2.05 after 2 hours. Tidal volume did not change after placebo (corresponding values, 8.71±1.83, 8.70±1.88 and 8.50±1.63). Neither furosemide nor placebo induced any change in resistance; baseline value in the furosemide group was 276.2±96.7 cm H2O/L/sec, and that for the control group was 250.8±95.0 cm H2O/L/sec. Secondary outcomes: urine output, serum electrolytes
Notes	Nebulization was done using an ultrasonic nebulizer placed in the inspiratory limb of the ventilator circuit. Pulmonary mechanics were measured at baseline and at 1 and 2 hours after aerosol administration. The authors measured static pulmonary mechanics using the passive occlusion technique.
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Unclear risk	Blinding of randomization: yes
Allocation concealment?	Low risk	Blinding of randomization: yes
Blinding? All outcomes	High risk	Blinding of intervention: no (nurses prepared the medication) Blinding of outcome: yes
Incomplete outcome data addressed? All outcomes	Low risk	Complete follow‐up: yes
Free of selective reporting?	Low risk
Free of other bias?	Unclear risk	Randomized clinical trial, cross‐over design with pooled data Washout 48 hours before the study and 48 hours at crossover