The present study evaluated the influence of intranasal cooling with balloon catheters, increased nasal ventilation, or percutaneous cooling of the carotid arteries on cerebral temperature balance and oxygenation in six healthy male subjects. Aortic arch and internal jugular venous blood temperatures were measured to assess the cerebral heat balance and corresponding paired blood samples were obtained to evaluate cerebral metabolism and oxygenation at rest, following 60 min of intranasal cooling, 5 min of nasal ventilation, and 15 min with carotid cooling. Intranasal cooling induced a parallel drop in jugular venous and arterial blood temperatures by 0.30 ± 0.08°C (mean ± SD), whereas nasal ventilation and carotid cooling failed to lower the jugular venous blood temperature. The magnitude of the arterio-venous temperature difference across the brain remained unchanged at -0.33 ± 0.05°C following intranasal and carotid cooling, but increased to -0.44 ± 0.11°C (P < 0.05) following nasal ventilation. Calculated cerebral capillary oxygen tension was 43 ± 3 mmHg at rest and remained unchanged during intranasal and carotid cooling, but decreased to 38 ± 2 mmHg (P < 0.05) following increased nasal ventilation. In conclusion, percutaneous cooling of the carotid arteries and intranasal cooling with balloon catheters are insufficient to influence cerebral oxygenation in normothermic subjects as the cooling rate is only 0.3°C per hour and neither intranasal nor carotid cooling is capable of inducing selective brain cooling.
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http://dx.doi.org/10.3389/fphys.2014.00079 | DOI Listing |
Cureus
October 2024
Department of Anesthesiology, Uniformed Services University of the Health Sciences, Bethesda, USA.
Cryobiology
December 2024
Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA. Electronic address:
Successful long-term cryobanking of multicellular tissues and organs at deep subzero temperatures calls for the avoidance of ice cryoinjury by reliance upon ice-free cryopreservation techniques. However, the quality of the cryopreserved material is the direct result of its ability to survive a host of harmful mechanisms, chief among which is overcoming the trifecta effects of ice crystallization, toxicity, and mechanical stress. This study aims at exploring improved conditions to scale-up ice-free cryopreservation by combining DP6 as a base cryoprotective agent (CPA) solution with an array of synthetic ice modulators (SIMs).
View Article and Find Full Text PDFNeurocrit Care
September 2024
Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles, Brussels, Belgium.
Background: Alterations in regional brain microcirculation have not been well studied in patients with sepsis. Regional brain microcirculation can be studied using contrast-enhanced brain ultrasound (CEUS) with microbubble administration.
Methods: CEUS was used to assess alterations in regional brain microcirculation on 3 consecutive days in 58 patients with sepsis and within 24 h of intensive care unit admission in 10 aged-matched nonseptic postoperative patients.
Resusc Plus
September 2024
Center for Resuscitation Medicine, University of Minnesota School of Medicine, Minneapolis, MN, USA.
Background: The role of hypothermia in post-arrest neuroprotection is controversial. Animal studies suggest potential benefits with lower temperatures, but high-fidelity ECPR models evaluating temperatures below 30 °C are lacking.
Objectives: To determine whether rapid cooling to 24 °C initiated upon reperfusion reduces brain injury compared to 34 °C in a swine model of ECPR.
Interv Neuroradiol
July 2024
Department of Radiology, New England Center for Stroke Research, University of Massachusetts Chan Medical School, Worcester, MA, USA.
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