Ricci 2012.

Study characteristics
Methods	Study design: randomised controlled trial, parallel arm Setting: paediatric cardiac ICU, Bambino Gesu' Children’s Hospital, Rome, Italy Study start/end dates or study duration: January 2008 to December 2010 Funding sources: not stated Declarations of interest: not stated
Participants	Sample size: 63 Patient age: 1 to 30 days Patient sex: 20 males and 12 females in the levosimendan group, 17 males and 14 females in the non‐levosimendan group Diagnosis/severity: risk‐adjusted classification for congenital heart surgery (RACHS) 3 and 4 procedures Inclusion criteria: neonates affected by transposition of the great arteries scheduled for elective surgery
Interventions	Intervention 1: continuous infusion of 0.1 μg/kg/min levosimendan for 72 hours added to standard inotropic support (milrinone 0.75 μg/kg/min and dopamine 5 to 10 μg/kg/min), started while weaning from CPB Intervention 2: standard post‐CPB inotrope infusion (milrinone 0.75 μg/kg/min and dopamine 5 to 10 μg/kg/min) Co‐interventions: adrenaline 0.05 to 0.3 μg/kg/min if necessary
Outcomes	Primary outcome(s): Incidence of LCOS (defined as tachycardia (heart rate > 170 beats/min) Oliguria (urine output < 0.5 mL/kg/h) Cold extremities (peripheral temperature < 27°C), with or without at least 30% difference in arterial to mixed venous oxygen saturation or metabolic acidosis (an increase in base deficit of greater than 4 or an increase in lactate of more than 2 mg/dL) on 2 successive blood gas measurements Cardiac arrest Need for extracorporeal membrane oxygenation Secondary outcome(s) Lactate Heart rate Mean arterial pressure Inotropic score Diuresis Need for peritoneal dialysis Mixed venous oxygen saturation Brain natriuretic peptide Number of ventilation days Paediatric cardiac ICU length of stay Survival Adverse events Outcomes were recorded until 72 hours postoperatively.
Notes	Intention‐to‐treat analysis: not stated, but no dropouts Trialists contacted: yes Unpublished information received: not available
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computerised random‐generation program
Allocation concealment (selection bias)	Low risk	Sealed envelopes containing the allocation group opened by a nurse in charge of preparing the infusions.
Blinding of participants and personnel (performance bias) All outcomes	High risk	No blinding, "newborns were openly randomized to receive a 72 h intravenous infusion of levosimendan...". "No blinding was necessary for the study, due to its open label design."
Blinding of outcome assessment (detection bias) All outcomes	High risk	No blinding. "No blinding was necessary for the study, due to its open label design."
Incomplete outcome data (attrition bias) All outcomes	Low risk	All outcomes listed in the methods section reported. No dropouts.
Selective reporting (reporting bias)	Low risk	No selective reporting suspected.
Other bias	Low risk	No other bias suspected.