Published online March 1, 2006
PEDIATRICS Vol. 117 No. 3 March 2006, pp. 843-850 (doi:10.1542/peds.2004-1587)
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow P3Rs: Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when P3Rs are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow E-mail this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My File Cabinet
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via ISI Web of Science (3)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Gebauer, C. M.
Right arrow Articles by Vogtmann, C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Gebauer, C. M.
Right arrow Articles by Vogtmann, C.
Related Collections
Right arrow Premature & Newborn

Hemodynamics Among Neonates With Hypoxic-Ischemic Encephalopathy During Whole-Body Hypothermia and Passive Rewarming

Corinna Mirjam Gebauer, MD, Matthias Knuepfer, MD, Eva Robel-Tillig, MD, Ferdinand Pulzer, MD and Christoph Vogtmann, MD

Department of Neonatology, Intensive Care Unit, Children's Hospital, University of Leipzig, Leipzig, Germany

OBJECTIVE. To assess changes in cardiac performance, with Doppler echocardiography, among newborns with hypoxic-ischemic encephalopathy during mild therapeutic hypothermia and during rewarming.

METHODS. For 7 asphyxiated neonates (birth weight: 1840–3850 g; umbilical artery pH: 6.70–6.95) who received mild whole-body hypothermia, the following hemodynamic parameters were determined immediately before rewarming (33°C) and during passive rewarming (35°C and 37°C): heart rate, systolic and diastolic blood pressure, core and peripheral temperatures, left ventricular ejection time, mean velocity of aortic flow, stroke volume, and cardiac output.

RESULTS. Heart rate decreased during hypothermia. Bradycardia, with heart rates below 80 beats per minute, did not occur. The median difference between core and peripheral temperatures decreased from 2.0°C (range: 0–6.2°C) during hypothermia to 0.7°C (range: 0.4–1.9°C) at normothermia. Cardiac output was reduced to 67% and stroke volume to 77% of the posthypothermic level. The median heart rate was 129 beats per minute before rewarming and increased to 148 beats per minute during complete rewarming. Before and during passive rewarming, hypotension was not observed. Before, during, and at the end of rewarming, the following parameters increased: mean velocity of aortic flow (median: 44, 55, and 58 cm/second, respectively), stroke volume (median: 1.42, 1.55, and 1.94 mL/kg, respectively), and cardiac output (median: 169, 216, and 254 mL/kg per minute, respectively). Left ventricular ejection time remained unchanged.

CONCLUSIONS. Whole-body hypothermia resulted in reduced cardiac output, which reached normal levels at the end of passive rewarming, at normothermia. Physiologic cardiovascular mechanisms seemed to be intact to provide sufficient tissue perfusion, with normal blood lactate levels.

Key Words: hypothermia • newborn • cardiac function • left ventricular ejection time

Accepted Jul 27, 2005.