-
- A R Laptook, L Shalak, and R J Corbett.
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9063, USA. abbot.laptook@utsouthwestern.edu
- Pediatrics. 2001 Nov 1;108(5):1103-10.
ObjectiveTo compare brain temperature and cerebral blood flow (CBF) during head and body cooling, with and without systemic hypoxemia.MethodsSeventeen newborn swine were studied for either measurement of brain temperature alone (n = 9) or measurement of brain temperature and CBF (n = 8). All animals were ventilated and instrumented, and temperature probes were inserted into the rectum, into the brain at depths of 2 and 1 cm from the cortical surface, and on the dural surface. Blood flow was measured with microspheres. The protocol consisted of a control period, an interval of either head or body cooling, and cooling with 15 minutes of superimposed hypoxia. After a 1-hour recovery period, animals were exposed to the same sequence except that the alternate mode of cooling was evaluated.ResultsHead cooling with a constant rectal temperature resulted in an increase in the temperature gradient across the brain from the warmer central structures to the cooler periphery (brain 2 cm - dura temperature: 1.3 +/- 1.1 degrees C at control to 7.5 +/- 3.5 degrees C during cooling). Hypoxia superimposed on head cooling decreased the temperature gradient by at least 50%. In contrast, body cooling was associated with an unchanged temperature gradient across the brain (brain 2 cm - dura temperature: 1.5 +/- 1.2 degrees C at control to 1.1 +/- 0.9 degrees C during cooling). Hypoxia superimposed on body cooling did not change brain temperature. Both modes of brain cooling resulted in similar reductions of global CBF ( approximately 40%) and O(2) uptake.ConclusionBrain hypothermia achieved through head or body cooling results in different brain temperature gradients. Alterations in systemic variables (ie, hypoxemia) alters brain temperature differently in these 2 modes of brain cooling. The mode of brain cooling may affect the efficacy of modest hypothermia as a neuroprotective therapy.
Notes
Knowledge, pearl, summary or comment to share?You can also include formatting, links, images and footnotes in your notes
- Simple formatting can be added to notes, such as
*italics*
,_underline_
or**bold**
. - Superscript can be denoted by
<sup>text</sup>
and subscript<sub>text</sub>
. - Numbered or bulleted lists can be created using either numbered lines
1. 2. 3.
, hyphens-
or asterisks*
. - Links can be included with:
[my link to pubmed](http://pubmed.com)
- Images can be included with:
![alt text](https://bestmedicaljournal.com/study_graph.jpg "Image Title Text")
- For footnotes use
[^1](This is a footnote.)
inline. - Or use an inline reference
[^1]
to refer to a longer footnote elseweher in the document[^1]: This is a long footnote.
.