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- Zetterling, Maria, 1966-
(författare)
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Clinical Studies in the Acute Phase of Subarachnoid Haemorrhage
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Patients admitted in similar clinical condition after spontaneous SAH can develop very different clinical courses. This could depend on the severity of the initial global ischemic brain injury at ictus. In the present study, we explored relations between clinical and radiological parameters at admission that indicate a more severe initial impact, and the following days hormone levels and brain metabolism. Early global cerebral oedema (GCE) on computed tomography occurred in 57 % of SAH patients and was associated with a more severe clinical condition. The brain’s glucose metabolism, measured with intracerebral microdialysis (MD), changed the first days. MD-glucose was initially high and MD-pyruvate low. MD-glucose gradually decreased and MD-pyruvate and MD-lactate increased, suggesting a transition to a hyperglycolytic state. This was more pronounced in patients with GCE. Similar patterns were seen for interstitial non-transmitter amino acids. From initial low concentrations, they gradually increased in parallel with MD-pyruvate. The amino acid concentrations were higher for patients admitted in better clinical condition. Insulin lowered MD-glucose and MD-pyruvate even when plasma glucose values remained high. P-ACTH and S-cortisol were elevated early after SAH. GCE was associated with higher S-cortisol acutely. Urine cortisol excretion, indicating levels of free cortisol, were higher in patients in a better clinical condition. Suppressed P-ACTH occurred in periods of brain ischemia. We suggest that GCE on the first CT scan is a warning sign indicating increased vulnerability if the patient is exposed to compromised energy supply or increased energy demand. Reduction of blood glucose after SAH should be done with caution. The temporal change of the glucose metabolism and the amino acid concentrations probably reflect activated repair mechanisms. This should be considered in the intensive care treatment of SAH patients. Finally, our results support earlier observations that the response of the hypothalamic-pituitary-adrenal system is important in critical care.
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| 2. |
- Zetterling, Maria, 1966-, et al.
(författare)
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Cortisol and ACTH dynamics in the acute phase of subarachnoid haemorrhage
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Ingår i: British Journal of Neurosurgery. - 0268-8697 .- 1360-046X.
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Tidskriftsartikel (refereegranskat)abstract
- Objective: An adequate response of hypothalamic-pituitary-adrenal (HPA) axis is important for survival and recovery after a severe disease. The hypothalamus and the pituitary glands are at risk of damage after subarachnoid haemorrhage (SAH). A better understanding of the hormonal changes would be valuable for optimizing care in the acute phase of SAH. Patients: 55 patients with spontaneous SAH were evaluated regarding morning levels of S-Cortisol and P-ACTH seven days after the bleeding. In a subgroup of 20 patients the diurnal changes of S-Cortisol and P-ACTH levels were studied and U-Cortisol measured. The relations of hormone levels to clinical and radiological parameters and to outcome were assessed. Results: S-Cortisol and P-ACTH were elevated the day of SAH. S-Cortisol levels below reference range were uncommon. Early global cerebral oedema was associated with higher S-Cortisol concentrations at admission and a worse WFNS and RLS85 grade. Patients in better WFNS grade had higher U-Cortisol levels. All patients showed diurnal variations of S-Cortisol and P-ACTH. A reversed diurnal variation of S-Cortisol was more frequently seen in mechanically ventilated patients. Periods of suppressed P-ACTH associated with S-Cortisol peaks occurred especially in periods of secondary brain ischemia. Conclusion: There is a HPA response acutely after SAH with an increase of P-ACTH and S-Cortisol levels. Higher U-Cortisol levels in patients in a better clinical grade may indicate a more robust response of the HPA system. Global cerebral oedema was associated with higher S-Cortisol levels at admission and may be the result of the stress response initiated by the brain injury. Periods of suppressed P-ACTH occurred particularly in periods of brain ischemia, indicating a possibly connection between brain ischemia and ACTH suppression. These two novel findings should be evaluated in further studies.
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| 3. |
- Zetterling, Maria, 1966-, et al.
(författare)
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Relation between brain interstitial and systemic glucose levels after subarachnoid hemorrhage
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Ingår i: Journal of Neurosurgery. - 0022-3085 .- 1933-0693.
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Tidskriftsartikel (refereegranskat)abstract
- Objects: The optimal blood glucose level after acute brain injury is not known. The aim of the present investigation was to study the relation between brain interstitial and systemic blood glucose levels during the acute phase after SAH. We also studied the effects of insulin administration on local brain energy metabolism. Methods: 19 patients with spontaneous SAH were monitored with intracerebral microdialysis (MD). The relation between plasma (P)-glucose and interstitial MD-glucose levels and the temporal pattern of MD-metabolites was studied seven days after SAH. With a target P-glucose of 5-10 mmol/L, the effect of insulin injection on brain energy metabolites (MD-glucose, lactate, pyruvate) and glutamate was evaluated. Results: The mean correlation coefficient between P-glucose and MD-glucose was 0.27 ± 0.27, (p=0.0005) with a high degree of individual variation. MD-glucose, MD/P-glucose ratio and MD-glutamate levels decreased in parallel with a gradual increase in MD-pyruvate and MD-lactate levels. There were no significant changes of MD-L/P ratio or MD-glycerol. Insulin administration induced a statistically significant decrease in MD-glucose and MD-pyruvate. Conclusion: After SAH, there was a positive correlation between P-glucose and MD-glucose levels with a high degree of individual variation. A gradual decline of MD-glucose and MD/P-glucose ratio and an increase of MD-pyruvate and MD-lactate levels during the first week after SAH could suggest a transition to a hyperglycolytic state with increased cerebral glucose consumption. Administration of insulin was related to lowering of MD-glucose and MD-pyruvate, often to critically low levels even though plasma glucose values remained above 6 mmol/L. Thus, P-glucose should not be low in the acute phase after SAH and administration of insulin should be done with caution, even more crucial when the cerebral glucose metabolism has recovered and an increased energy demand is developing in the injured, repairing brain.
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