| Study characteristics |
| Methods |
Single‐centre randomised double‐blind placebo‐controlled trial |
| Participants |
22 preterm infants (≤ 32 weeks) mechanically ventilated since birth, with postnatal age 12 to 48 hours, with an indwelling arterial umbilical line
Exclusion criteria: maternal opioid use or abuse during pregnancy, labour, or delivery; administration of muscle relaxants, analgesics, or sedatives before or during the study period; grade III to IV intraventricular haemorrhage; central nervous system malformations; gross neurological abnormalities; intubation or re‐intubation within 4 hours before patient observation |
| Interventions |
Intervention group (n = 11): single dose of fentanyl (3 mcg/kg) injected over 2 minutes
Control group (n = 11): 0.2 mL normal saline injected over 2 minutes |
| Outcomes |
Serum cortisol and growth hormone; blood glucose and lactate; vital signs. Behavioural pain scales: modified postoperative COMFORT Scale and NFCS for 10 minutes. All outcomes measured before treatment, at 30 minutes and at 60 minutes after treatment |
| Notes |
|
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Unclear risk |
Method of randomisation was not stated |
| Allocation concealment (selection bias) |
Unclear risk |
The use of sealed envelopes was stated, but it is not clear how allocation concealment was dealt with |
| Blinding of participants and personnel (performance bias) |
Low risk |
Quote: "the drug randomization code was broken and statistical analysis was performed after all data had been recorded" |
| Blinding of outcome assessment (detection bias) |
Low risk |
Assessors were stated to be blinded to treatment |
| Incomplete outcome data (attrition bias) |
Low risk |
Outcomes were reported for all patients enrolled |
| 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 |
