| Study characteristics |
| Methods |
Single‐centre randomised double‐blind placebo‐controlled trial |
| Participants |
41 preterm (< 34 weeks) infants who required mechanical ventilation and received surfactant (Curosurf) for hyaline membrane disease
Exclusion criteria: babies who did not have an arterial line in situ |
| Interventions |
Morphine group (n = 21): loading dose 100 mcg/kg/hour for 2 hours followed by 25 mcg/kg/hour as a continuous infusion. Treatment was continued until the baby was on a ventilator
Placebo group (n = 20): dextrose 5% |
| Outcomes |
Catecholamine; plasma levels; blood pressure; heart rate and ventilator setting (peak inspiratory pressure and oxygen concentration) at study entry and after 6 hours' treatment; arterial/alveolar oxygen ratio at 0 hours and at 24 hours; pain score (based on level of consciousness, crying, posture, and facial expression); days on ventilator; air leaks; intraventricular haemorrhage; PDA; death during first 6 months of life
5 to 6 years' follow‐up outcomes: IQ (by Weschler Preschool and Primary Scale of Intelligence); motor impairment (by Movement Assessment Battery for Children); behaviour problems (by Child Behaviour Checklist completed by a parent); blood thyroid‐stimulating hormone level |
| Notes |
|
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Low risk |
Randomisation was performed by using a stratified table |
| Allocation concealment (selection bias) |
Low risk |
Pharmacy allowed for adequate allocation concealment |
| Blinding of participants and personnel (performance bias) |
Low risk |
Caregivers were stated to be blinded, except for the consultant physician responsible for the baby |
| Blinding of outcome assessment (detection bias) |
Low risk |
Assessors were stated to be blinded |
| Incomplete outcome data (attrition bias) |
Low risk |
There was no loss to follow‐up for clinical outcomes. A power calculation was made for differences in catecholamines levels. Analysis of clinical data was performed on an intention‐to‐treat basis. The trial was terminated after an interim analysis showed differences in adrenaline concentrations |
| Selective reporting (reporting bias) |
Unclear risk |
Trial not registered; protocol not available |
| Other bias |
Low risk |
Study appears to be free of other sources of bias |
