The Effect of Whole-Body Cooling on Hematological and Coagulation Parameters in Asphyxic Newborns

Abstract

Although moderate therapeutic hypothermia is the only proven neuroprotective therapy in neonatal hypoxic ischemic encephalopathy secondary to perinatal asphyxia (PA), there is lack of data for its effect on hemostasis. To investigate the effect of neonatal asphyxia on hemostasis and to evaluate the effect of whole body cooling on hematological parameters. Hematological parameters evaluated on the first day of patients with PA before start of hypothermia were compared with those of healthy controls. The effects of whole body cooling on the same parameters were also evaluated on the fourth day. A total of 17 neonates with PA and 15 healthy controls were included. Mean values for prothrombin time (PT), international normalized ratio (INR), activated partial thromboplastin time (aPTT), and d-dimer obtained on the first day were significantly higher in the PA group compared to healthy controls (P ≤ .001 for all comparisons), whereas platelet count, levels of fibrinogen, factors II, V, VII, IX, X, and XI were significantly lower (P ≤ .005 for all comparisons). Levels of factor XIII were normal in both groups. In the study group, mean values for PT, INR, aPTT, and d-dimer evaluated on postnatal day 4 were significantly lower compared to values obtained on the first day of birth in PA group (P < .05 for all comparisons), with statistically significant increases in mean levels of fibrinogen, factor II, V, VII, IX, X, and XII (P < .05 for all comparisons). PA results in significant reductions in levels of factors of the extrinsic pathway and has been associated with thrombocytopenia and disseminated intravascular coagulation. Hypothermia may actually improve the clinical picture in such patients rather than aggravating the hemostatic disturbance, particularly with the implementation of supportive treatment.

Thrombocytopenia in late preterm and term neonates after perinatal asphyxia

“…Our data suggest that therapeutic hypothermia does not independently cause neonatal thrombocytopenia. Hypothermia for 72 hours has recently become a common and effective means of improving neurodevelopment of term neonates after perinatal asphyxia . Hypothermia does adversely affect PLT function, as manifested by prolongation of the bleeding time and lengthening of the PFA100 closure time .…”

Passive hypothermia (≥35 - <36°C) during transport of newborns with hypoxic-ischaemic encephalopathy

“…In one study, as many as one third of infants arrived in NICU with a core temperature of <33°C [23]. Deep hypothermia may induce bradycardia and arrhythmia [20], thrombocytopaenia [6] requiring platelet transfusion [21] although overall haemostasis may not be affected [22]. …”

Purpura Fulminans after Therapeutic Hypothermia in an Asphyxiated Neonate with Streptococcemia

“…13 A recently published study showed that neonatal platelet function is impaired by therapeutic hypothermia, a phenomenon that is reversible by reestablishing regular body temperature. 14 Moreover, plasmatic coagulation factors in neonates are also out of normal ranges during therapeutic hypothermia, 15 and in contrast to the results of the RCTs, some authors described significantly higher prothrombin times and lower platelet counts with more patients requiring plasma and platelet transfusions in the hypothermic group. 16 To add some diagnostic considerations, measurement of platelet function is not available in the routine laboratory workup at the NICU.…”