• 
• 

Three Part Question

Does delivery of [preterm infants] into [polyethylene bags] achieve [temperature control without adverse effects]?

Clinical Scenario

A 28-week preterm infant is resuscitated under radiant warmer in the labour ward. The admission temperature of the infant to intensive care is 35.5ºC. The nurse looking after the baby claims that hypothermia could have been prevented by delivery of the baby into plastic bag. Is there any evidence to support her claim?

Search Strategy

Primary source: Medline 1966-2004, EMBASE 1974-2004 and CINHAL 1982-2004 using the Dialog Datastar.
Secondary source: The Cochrane library (2004, Issue 1).
Primary source: The search term [Polyethylene AND temperature] Filter: controlled clinical trial. Limit to human, newborns and English language. Hits: Medline (1), EMBASE (1) and CINAHL (1).
Secondary source: The search term 'polyethylene AND temperature. Hits: 21 systematic reviews (5), Controlled trials (16).

Search Outcome

2 relevant studies identified (see table)

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Vohra S et al 1999 Canada	62 consecutive infants delivered at <32 weeks' gestation were stratified by gestational age and randomly allocated to resuscitation with polyethylene wrap.	Randomized controlled trial	Admission rectal temperature in infants <28 weeks' gestation	Difference in means = 1.9 C (P <0.001)	59 of 62 recruited infants completed the study.
			Admission rectal temperature in infants of 28 to 31 weeks' gestation	Difference in means = 0.17 C (P =0.47)
			Mortality	Non-wrap=5, Wrap= 0 (P =0.04)
			Temperature in survivors/non survivors	Non- Wrap=35.1 C, Wrap=36.5 C (P =0.001)
Lenclen R et al 2002 France	120 infants at less than 33 weeks' gestation. Polyethylene wrap= 60 and non wrap= 60	Retrospective, Matched pair analysis	Admission rectal temperature	Difference in means = 0.8 degree C (p< 0.0001)	Retrospective review
			Hypothermia < 35.5 degrees C	Wrap=8.3%, Non -wrap=55%
			Side effects (skin burns, infection or hyperthermia)	None

Comment(s)

Hypothermia increases neonatal mortality. Extremely preterm infants are at increased risk of evaporative heat loss in the labour ward. Recent studies have shown polyethylene wraps to be effective in maintaining temperature if placed into immediately after delivery before drying. The search yielded 7 clinical trials of which 2 were relevant. The other papers addressed the same question but with different intervention and therefore were excluded.

Clinical Bottom Line

Delivery of preterm infants (< 28 weeks) into polyethylene bags before drying is effective in maintaining admission rectal temperature.

References

1. Vohra S, Frent G, Campbell V, Abbott M, Whyte R Effect of polyethylene occlusive skin wrapping on heat loss in very low birth weight infants at delivery: a randomized trial J Pediatr 1999 May;134 (5):547-51
2. Lenclen R, Mazraani M, Jugie M, Couderc S, Hoenn E, Carbajal R, Blanc P, Paupe A. [Use of a polyethylene bag: a way to improve the thermal environment of the premature newborn at the delivery room] Arch Pediatr 2002 Mar;9(3):238-44