title: Effect of therapeutic hypothermia in neonates with hypoxic-ischemic encephalopathy on platelet function.
abstract: OBJECTIVE
  Platelet dysfunction has been described in adults during hypothermia. We sought to determine whether it also occurs in neonates.
  
  
  METHODS
  We measured bleeding times and PFA-100 (platelet function analyzer) times in 10 neonates with hypoxic-ischemic encephalopathy during and after head cooling.
  
  
  RESULTS
  The 10 neonates were born at 38.2 ± 1.6 weeks' gestation (mean ± SD), with birth weights of 3,222 ± 746 g, pH 6.79 ± 0.17, base excess -25 ± 8, and 10-min Apgar 4 ± 2. Cooling was instituted 111 min (range: 66-180) after birth and continued 72 h. Bleeding times before cooling averaged 170 s (95% CI: 100-240). These lengthened during hypothermia, averaging 410 s (p = 0.000) and shortened after rewarming (p = 0.000). PFA-100 times were similar: prolongation during cooling and normalization after rewarming. Six neonates had clinical bleeding problems in the first 24 h of cooling, but were managed successfully, and no intracranial hemorrhages were identified.
  
  
  CONCLUSIONS
  Defective platelet plug formation occurs during therapeutic hypothermia of neonates in a manner similar to that described in adults. Platelet impairment can be severe, but rapidly improves after rewarming.
authors.affiliation: Department of Women and Newborns, Intermountain Healthcare, Salt Lake City, Utah 84403, USA. rdchris4 @ ihc.com
authors.forename: Robert D
authors.initials: RD
authors.lastname: Christensen
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Sheffield
authors.forename: Diane K
authors.initials: DK
authors.lastname: Lambert
authors.forename: Vickie L
authors.initials: VL
authors.lastname: Baer
mesh_terms: D001760:Bleeding Time; D001792:Blood Platelets / Q000502:physiology*; D005260:Female; D006257:Head / Q000503:physiopathology; D006801:Humans; D007036:Hypothermia, Induced; D020925:Hypoxia-Ischemia, Brain / Q000628:therapy*; D007231:Infant, Newborn; D008297:Male; D017694:Rewarming; D016896:Treatment Outcome