| Hypoxemic reperfusion exacerbates the neurological injury sustained during neonatal deep hypothermic circulatory arrest: a model of cyanotic surgical repair. | |
| | |
MedLine Citation:
|
PMID: 17331738 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
OBJECTIVE: Deep hypothermic circulatory arrest (DHCA) is frequently used in infants undergoing the Norwood procedure. These infants are necessarily hypoxemic after separation from CPB. Considerable energy has been spent characterizing the physiological and histological consequences of DHCA, but these have largely focused on a normoxemic period of reperfusion. Furthermore, evidence has accumulated to suggest that the cerebral vascular autoregulatory mechanisms are dysfunctional following DHCA. In particular, the vasodilatation that elevates cerebral blood flow (CBF) in response to hypoxemia is absent. This study therefore aimed to investigate whether post-CPB hypoxemia exacerbates brain injury resulting from DHCA. METHODS: Twelve neonatal piglets were subjected to 2h DHCA and then separated from CPB. They were then randomized to either: Group 1, normoxic ventilation (n=5); or Group 2, hypoxemia (n=7), in which the arterial PaO(2) was reduced to 40-50 mmHg for the duration of reperfusion. Following a 20 h period of warm reperfusion, the animals were perfusion fixed and the brain analyzed for histological evidence of injury. Nine additional animals were studied in one of three control groups. RESULTS: All animals survived the protocol. Post-operative parameters - including mean arterial pressure, acid-base status, inotrope requirements and arterial PaCO(2) - were similar. None of the control animals had any evidence of ischemia. Group 1 animals had moderate injury (total score 7.4+/-1.6). In Group 2, three animals sustained irretrievable brain injury evidenced by gross edema and early liquefactive necrosis. The remaining four had severe ischemic histological changes (score 14.5+/-1.6, p<0.03). CONCLUSIONS: Hypoxemic reperfusion after prolonged DHCA results in increased neuronal loss. The use of DHCA for staged palliation may confer disproportionately greater cerebral risk than other patient groups. Alternatively, methods to augment oxygen delivery - such as by ECMO - may be of particular benefit in the early re-perfusion window. |
| | |
Authors:
|
Edward J Hickey; Xiaomang You; Vassil Kaimaktchiev; Ross M Ungerleider |
Related Documents
:
|
3707248 - Myocardial protective effect of amiodarone in hypertrophied hearts during global ischemia. 8759248 - Effects of propafenone on the median frequency of ventricular fibrillation in langendor... 1420248 - Tpen, a transition metal chelator, improves myocardial protection during prolonged isch... 12557908 - Electrophysiological studies with repeated episodes of ischaemia on isolated rat heart. 12498268 - Rapid screening of pka values of pharmaceuticals by pressure-assisted capillary electro... 2610998 - Noninvasive ambulatory blood pressure control in normotensive pregnant women. |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't Date: 2007-02-28 |
Journal Detail:
|
Title: European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery Volume: 31 ISSN: 1010-7940 ISO Abbreviation: Eur J Cardiothorac Surg Publication Date: 2007 May |
Date Detail:
|
Created Date: 2007-04-09 Completed Date: 2007-07-19 Revised Date: 2007-11-15 |
Medline Journal Info:
|
Nlm Unique ID: 8804069 Medline TA: Eur J Cardiothorac Surg Country: Germany |
Other Details:
|
Languages: eng Pagination: 906-14 Citation Subset: IM |
Affiliation:
|
Oregon Health Science University, Portland, Oregon, USA. edward.hickey@sickkids.ca |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Animals Animals, Newborn Anoxia / pathology, physiopathology* Brain / pathology, physiopathology Brain Ischemia / etiology, pathology, physiopathology* Cardiopulmonary Bypass / methods* Cerebrovascular Circulation / physiology Circulatory Arrest, Deep Hypothermia Induced / adverse effects*, methods Disease Models, Animal Microscopy, Fluorescence / methods Myocardial Reperfusion / adverse effects Swine |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Adult-onset hypothyroidism facilitates and enhances LTD: reversal by chronic nicotine treatment.
Next Document: Collision-activated dissociation, infrared multiphoton dissociation, and electron capture dissociati...