Ebade 2013.

Study characteristics
Methods	Study design: randomised controlled trial, parallel arm Setting: Pediatrics, Cairo University Hospital Study start/end dates or study duration: from January 2011 until January 2012 Funding sources: not stated Declarations of interest: not stated
Participants	Sample size: 50 Patient age: 7 to 38 months Patient sex: 13 males and 12 females in the dobutamine group, 16 males and 9 females in the levosimendan group Diagnosis/severity: all with biventricular heart defects: atrial or ventricular septal defects with high systolic pulmonary artery pressure exceeding 50% of systemic systolic pressure Inclusion criteria: patients with either atrial or ventricular septal defects with high systolic pulmonary artery pressure exceeding 50% of systemic systolic pressure, assigned for surgical correction of the defect with cardiopulmonary bypass
Interventions	Intervention 1: levosimendan infusion started immediately after declamping of the aorta with an initial loading dose of 15 μg/kg given over a 10‐minute period, followed by infusion at 0.1 to 0.2 μg/kg/min. The exact rate of study drug infusion was titrated according to haemodynamic data. Postoperative infusion continued for 24 h from the time of admission to the ICU. Intervention2: dobutamine infusion started immediately after declamping of the aorta, at 4 to 10 μg/kg/min. The exact rate of study drug infusion was titrated according to haemodynamic data. Postoperative infusion continued for 24 h from the time of admission to the ICU. Co‐interventions: nitroglycerine infusion 1 to 2 μg/kg/min after induction of anaesthesia until weaning from CPB for both groups, in case of hypotension phenylephrine 1 to 2 μg/kg bolus doses
Outcomes	Primary outcome(s): Mean pulmonary artery pressure recorded preoperatively by transthoracic echocardiography, intraoperatively by pulmonary artery catheter, postoperatively by transoesophageal echocardiography; assessment at 6 time points from opening of the pericardium until 20 hours after ICU admission Cardiac Index recorded by transoesophageal echocardiogram, assessment at 4 time points from opening of the pericardium until 20 hours after ICU admission Secondary outcome(s): duration of mechanical ventilation, duration of ICU stay
Notes	Exact rate of infusion for intervention and control drug was titrated according to haemodynamic data Intention‐to‐treat analysis: yes Trialists contacted: yes Unpublished information received: not available
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	“Patients were randomized using sealed envelopes and allocated to two equal groups”. No further details of random sequence generation stated.
Allocation concealment (selection bias)	Low risk	Allocation concealment was performed using sealed envelopes.
Blinding of participants and personnel (performance bias) All outcomes	High risk	No blinding reported, even though one of the study drugs was levosimendan, which is a yellow solution and could therefore be distinguished from other infusions by the patient and bedside personnel.
Blinding of outcome assessment (detection bias) All outcomes	High risk	No blinding. Also, measurement of cardiac index by transoesophageal Doppler is not considered to be gold standard. Especially in the setting of an unblinded study, there is a certain risk of detection bias.
Incomplete outcome data (attrition bias) All outcomes	Low risk	All outcomes listed in the methods section reported.
Selective reporting (reporting bias)	Low risk	No selective reporting suspected.
Other bias	Low risk	No other bias suspected.