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Influence of intranasal and carotid cooling on cerebral temperature balance and oxygenation.

Nybo L, Wanscher M, Secher NH - Front Physiol (2014)

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Nutrition, Exercise and Sport Sciences, University of Copenhagen Copenhagen, Denmark.

ABSTRACT
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.

No MeSH data available.


Related in: MedlinePlus

Top panel. Average face skin (mean of cheek and forehead), neck skin over the carotid arteries, and intra-nasal temperatures at rest (baseline), during intranasal cooling, increased nasal ventilation and carotid cooling. Lower panel shows the delta difference between arterial (aortic arch) and internal jugular venous blood temperatures at rest during intranasal cooling, increased nasal ventilation and carotid cooling. *Indicates that the value is significantly different from corresponding value at rest (P < 0.05).
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Figure 2: Top panel. Average face skin (mean of cheek and forehead), neck skin over the carotid arteries, and intra-nasal temperatures at rest (baseline), during intranasal cooling, increased nasal ventilation and carotid cooling. Lower panel shows the delta difference between arterial (aortic arch) and internal jugular venous blood temperatures at rest during intranasal cooling, increased nasal ventilation and carotid cooling. *Indicates that the value is significantly different from corresponding value at rest (P < 0.05).

Mentions: There was a small but significant decline in internal jugular venous blood temperature during the 1 h period with nasal cooling (Figure 1) occurring in parallel with the drop in body temperature as the arterio-venous temperature difference across the brain remained unchanged at −0.33 ± 0.05°C. Furthermore, the arterio-venous temperature difference across the brain was not changed during carotid cooling, whereas it was widened to −0.44 ± 0.11 °C following the period with nasal ventilation. Thus, the jugular venous blood temperature remained in the range 0.3–0.44°C above that of the arterial blood despite marked reductions in intranasal, neck, and face skin temperatures as illustrated in Figure 2.


Influence of intranasal and carotid cooling on cerebral temperature balance and oxygenation.

Nybo L, Wanscher M, Secher NH - Front Physiol (2014)

Top panel. Average face skin (mean of cheek and forehead), neck skin over the carotid arteries, and intra-nasal temperatures at rest (baseline), during intranasal cooling, increased nasal ventilation and carotid cooling. Lower panel shows the delta difference between arterial (aortic arch) and internal jugular venous blood temperatures at rest during intranasal cooling, increased nasal ventilation and carotid cooling. *Indicates that the value is significantly different from corresponding value at rest (P < 0.05).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3936139&req=5

Figure 2: Top panel. Average face skin (mean of cheek and forehead), neck skin over the carotid arteries, and intra-nasal temperatures at rest (baseline), during intranasal cooling, increased nasal ventilation and carotid cooling. Lower panel shows the delta difference between arterial (aortic arch) and internal jugular venous blood temperatures at rest during intranasal cooling, increased nasal ventilation and carotid cooling. *Indicates that the value is significantly different from corresponding value at rest (P < 0.05).
Mentions: There was a small but significant decline in internal jugular venous blood temperature during the 1 h period with nasal cooling (Figure 1) occurring in parallel with the drop in body temperature as the arterio-venous temperature difference across the brain remained unchanged at −0.33 ± 0.05°C. Furthermore, the arterio-venous temperature difference across the brain was not changed during carotid cooling, whereas it was widened to −0.44 ± 0.11 °C following the period with nasal ventilation. Thus, the jugular venous blood temperature remained in the range 0.3–0.44°C above that of the arterial blood despite marked reductions in intranasal, neck, and face skin temperatures as illustrated in Figure 2.

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Nutrition, Exercise and Sport Sciences, University of Copenhagen Copenhagen, Denmark.

ABSTRACT
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.

No MeSH data available.


Related in: MedlinePlus