Therapeutic hypothermia for asphyxiated newborns: experience of an Israeli tertiary center.

BACKGROUND: Major advances in the treatment of perinatal asphyxial-hypoxic ischemic encephalopathy (PA-HIE) followed the translation of hypothermia animal studies into successful randomized controlled clinical trials that substantially influenced the current standard of care. OBJECTIVES: To present our preliminary experience with the first cases of clinical application of therapeutic hypothermia for PA-HIE in what we believe is the first report on nonexperimental hypothermia for PA-HIE from Israel. METHODS: We reviewed the medical records, imaging scans, electroencephalograms and outcome data of the six identified asphyxiated newborns who were managed with hypothermia in our services in 2008-2009. RESULTS: All asphyxiated newborns required resuscitation and were encephalopathic. Systemic hypothermia (33.5 degrees C) was begun at a median age of 4.2 hours of life (range 2.5-6 hours) and continued for 3 days. All six infants showed a significantly depressed amplitude integrated electroencephalography background, and five had electrographic seizures. One infant died (16%) after 3.5 days. Major complications included fat necrosis and hypercalcemia (n=1), pneumothorax (n=1), and meconium aspiration syndrome (n=2). None of the infants developed major bleeding. Neurodevelopmental followup of the five surviving infants at median age 7.2 months (4.1-18.5 months) revealed developmental delays (Battelle screening), with their motor scores ranging from -1 to +1 standard deviation (Bayley scale). None developed feeding problems, oculomotor abnormalities, spasticity or seizures. CONCLUSIONS: Our preliminary experience with this novel modality in a large Tel Aviv neonatal service is consistent with the clinical findings of published trials.

Increased energy expenditure after dilutional exchange transfusion for neonatal polycythemia.

OBJECTIVE: Hypothermia is a known symptom of neonatal polycythemia (NP) and its pathophysiology is unclear. The effect of partial dilutional exchange transfusion (PET) upon resting energy expenditure (REE) is unknown. We aimed to test the hypothesis that PET leads to an increase in REE. STUDY DESIGN: 11 patients with NP who underwent PET and 10 controls without polycythemia were studied. NP was defined as a venous HCT >/=0.65. Per protocol, symptomatic infants and/or those with venous HCT > or =0.70 underwent PET. REE was measured just prior and 23 hours after PET in patients with NP and at identical ages in the control group. Infants were studied in a skin servo controlled radiant warmer, while clinically and thermally stable, prone and asleep. Measurements were stopped during body movements (less than 5% of the time of measurement). Metabolic measurements were performed by indirect calorimetry, using the Deltatrac II Metabolic monitor (Datex-Ohmeda, Helsinki, Finland). This instrument uses the principle of the open circuit system that allows continuous measurements of oxygen consumption (Vo(2)) and carbon dioxide production (Vco(2)) using a constant flow generator. REE measurements were corrected for the infant weight (Kcal/kg/d). Comparison of REE values between groups was performed using paired Wilcoxon ranked test. RESULTS: Patients with and without NP had nearly identical baseline REE. In patients with NP, REE increased from 44.0 +/- 6.6 Kcal/Kg/d to 48.3 +/- 5.1 Kcal/Kg/d after PET (P<0.05). Furthermore, the increase in REE following PET correlated inversely with the decrease in hematocrit. There was no significant change in REE over time in the control group. In the NP group, symptomatic infants (n=5) had a significantly greater increase in REE following PET than non-symptomatic ones (1.4 +/- 6.3 vs. 7.8 +/- 4.9 Kcal/Kg/d, p<0.05). CONCLUSIONS: Energy expenditure of polycythemic infants increases following PET, in a manner proportional to the decrease in hematocrit. Symptomatic polycythemic infants have a greater rise in REE following PET than non-symptomatic ones. We speculate that polycythemia leads to a decreased REE that might be remedied by PET.