Abstract | OBJECTIVE: DESIGN: Prospective interventional animal study. SETTING: Surgical laboratory and hyperbaric chamber. SUBJECTS: Twenty-two Landrace pigs. INTERVENTIONS: Under general anesthesia, probes to measure intracranial pressure, brain oxygen tension (PbtO2), and brain microdialysis, and electrodes for electroencephalography were placed. The electroencephalogram (quantified using temporal brain symmetry index) was suppressed during 1 hour by repeated injection of air boluses through a catheter placed in the right ascending pharyngeal artery. Hyperbaric oxygenation was administered using U.S. Navy Treatment Table 6 after 2- or 4-hour delay. Control animals were maintained on an inspiratory oxygen fraction of 0.4. MEASUREMENTS AND MAIN RESULTS: Intracranial pressure increased to a mean maximum of 19 mm Hg (SD, 4.5 mm Hg) due to the embolization procedure. Hyperbaric oxygenation significantly increased PbtO2 in both groups treated with hyperbaric oxygenation (mean maximum PbtO2, 390 torr; SD, 177 torr). There were no significant differences between groups with regard to temporal brain symmetry index (control vs 2-hr delay, p = 0.078; control vs 4-hr delay, p = 0.150), intracranial pressure, and microdialysis values. CONCLUSIONS: We did not observe an effect of hyperbaric oxygenation on cerebral function after a delay of 2 or 4 hours. The injury caused in our model could be too severe for a single session of hyperbaric oxygenation to be effective. Our study should not change current hyperbaric oxygenation strategies for cerebral arterial gas embolism, but further research is necessary to elucidate our results. Whether less severe injury benefits from hyperbaric oxygenation should be investigated in models using smaller amounts of air and clinical outcome measures.
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Authors | Robert P Weenink, Markus W Hollmann, Xavier C E Vrijdag, Krijn P Van Lienden, Diederick W De Boo, Markus F Stevens, Thomas M Van Gulik, Robert A Van Hulst |
Journal | Critical care medicine
(Crit Care Med)
Vol. 41
Issue 7
Pg. 1719-27
(Jul 2013)
ISSN: 1530-0293 [Electronic] United States |
PMID | 23632435
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Topics |
- Animals
- Electroencephalography
- Embolism, Air
(physiopathology, therapy)
- Female
- Hyperbaric Oxygenation
(methods)
- Intracranial Embolism
(physiopathology, therapy)
- Intracranial Pressure
- Microdialysis
- Swine
- Time Factors
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