JOURNAL CLUB · LANDMARK TRIAL
Randomised trial of occlusive wrap for heat loss prevention in preterm infants (HeLP)
Reilly MC, Vohra S, Rac VE, et al. J Pediatr. 2015;166(2):262-8. A multicentre, international randomised controlled trial.
HYPOTHERMIA -
NOT DEATHS
No difference in mortality
Death 20.5% (wrap) vs 20% (control); OR 1.0 (95% CI 0.7-1.5), p=0.85 - despite a 10-year recruitment period.
Warmer, but only modestly
Admission temperature was higher with wrap, but by only about 0.6 degrees C.
Stopped early and underpowered
Powered for 1604 to show a 25% mortality reduction; terminated for futility with only 801 analysed.
Signals in the smallest babies
In 24-25 week infants, wrap was linked to less treated PDA and pulmonary haemorrhage; a lower 1-minute Apgar was also seen (exploratory).
WHY THIS MATTERS
- Hypothermia at birth is associated with mortality in very immature infants
- Extremely preterm skin loses heat rapidly by evaporation
- Earlier small trials suggested wrap reduced hypothermia and perhaps death
- Meta-analysis was inconclusive for death - a large RCT was needed
- Wrap is cheap, simple and widely used - worth knowing what it does and does not do
STRENGTHS
- The largest RCT of occlusive wrap in extremely preterm infants
- Multicentre and international
- Randomisation stratified by gestational age
- Answered the mortality question directly
- Confirmed the wrap is safe and reduces hypothermia
LIMITATIONS
- Stopped early for futility - underpowered for mortality and exploratory outcomes
- Unmasked - caregivers knew the intervention (performance / detection bias)
- Only ~0.6 degree temperature difference, with many wrap-placement protocol violations
- Took 10 years; practice and heat-loss awareness shifted during the trial
- Mostly antenatal consent - may not represent the whole population
Practice implications
Hypothermia on admission is common in extremely preterm babies and is associated with worse outcomes, so heat-loss prevention is a core part of delivery-room care. HeLP confirmed that an occlusive polyethylene wrap is safe and reduces hypothermia, but it did not reduce mortality, and the temperature gain was modest. This fits the wider view that hypothermia may be as much a marker of illness severity as a direct cause of death. Even so, because the wrap reliably keeps babies warmer at little cost or harm, it remains recommended: current ANZCOR / international guidance is to place infants <32 weeks in a plastic wrap or bag under radiant heat without drying. Use it as part of a thermal bundle, and check placement is correct.
Is hypothermia a cause of death, or a marker of how sick the baby already is?
Why keep recommending the wrap when it did not change mortality?
What else is in your delivery-room thermal bundle for a 25-weeker?
How does stopping a trial early change how you read its secondary outcomes?
J Pediatr 2015 ANZCOR
Newborn resuscitation NEODRY
Drying before wrapping LANDMARK TRIALS
More trials to know
Take-home message: HeLP, the largest trial of occlusive wrap in extremely preterm infants, confirmed that a polyethylene wrap at birth is safe and reduces hypothermia - but it did not reduce mortality (20.5% vs 20%), and the temperature gain was modest (~0.6 C). Hypothermia may be as much a marker of illness severity as a cause of death. Because the wrap keeps babies warmer at little cost or harm, it remains standard delivery-room care for very preterm infants - just do not expect it, on its own, to change survival.
For educational purposes only. Journal club appraisal - figures paraphrased from the published trial and later reviews; read the full article for complete data. Always align practice to current ANZCOR/NRP guidelines.