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Biomedical subjects

J Astrup

Publications and source records attributed to J Astrup.

At least 37 records · Page 2Linked to original sources
PubMed1996

CO(2) and indomethacin vasoreactivity in patients with head injury.

The purpose of this study was to compare the effect of hyperventilation and indomethacin on cerebral circulation, metabolism and pressures in patients with acute severe head injury in order to see if indomethacin may act supplementary to hyperventilation. Fourteen severely head injured patients entered the study. Intracranial pressure (ICP), mean arterial blood pressure (MABP) and cerebral perfusion pressure (CPP) were monitored continuously. Within the first four days after the trauma the CO(2) and indomethacin vasoreactivities were studied by measurements of cerebral blood flow (CBF) (Cerebrograph 10a, intravenous (133)Xe technique) and arterio-venous difference of oxygen (AVdO(2)). Ischaemia was evaluated from changes in CBF, saturation of oxygen in the jugular bulb (SvjO(2)), lactate and lactate/oxygen index (LOI). Data are presented as medians and ranges, results are significant unless otherwise indicated. Before intervention ICP was well controlled ,(14.8 (9-24) mmHg) and basic CBF level was 39.1 (21.6-75.0) ml/100 g/min). The arterio-venous oxygen differences were generally decreased (AVdO(2) = 4.3 (1.8-8.1) ml/100 ml) indicating moderate luxury perfusion. Levels of CMRO(2) were decreased (1.54 (0.7-3.2) ml/100 g/min) as well. During hyperventilation (delta PaCO(2)=0.88 (0.62-1.55) kPa) CBF decreased with 11.8 (-33.4-29.7) %/kPa and ICP decreased with 3.8 (0-10) mmHg. AVdO(2) increased 34.0 (4.0-139.2) %/kPa, MABP was unchanged, CMRO(2) and CPP increased (delta CPP = 3.9 (-10-20) mmHg). AVD (lactate) and LOI were unchanged. No correlations between CBF responses to hypocapnia and outcomes were observed. An i.v. bolus dose of indomethacin (30 mg) decreased CBF 14.7 (-16.7-57.4)% and ICP decreased 4.3 (-1-17) mmHg. AVdO(2) increased 27.8 (-40.0-66.7)%, MABP (delta MABP = 4.9 (-2-21) mmHg) and CPP (delta CPP = 8.7 (3-29) mmHg) increased while CMRO2 was unchanged. No changes in AVd (lactate) and LOI indicating cerebral ischaemia were found. Compared to hyperventilation (changes per 1 kPa, at PaCO(2) level = 4.05 kPa) the changes in MABP, CPP and CBF were significantly greater after indomethacin, while the changes in AVdO(2), ICP, SvjO(2) and LOI were of the same order of magnitude. No correlation between relative reactivities to indomethacin and CO(2), evaluated from changes in CBF and AVdO(2), or between the decrease in ICP after the two procedures were found. Thus, some patients reacted to indomethacin but not to hyperventilation, and vice versa. These results suggest that indomethacin and hyperventilation might act independently, or in a complementary fashion in the treatment of patients with severe head injury.

Adult↗
PubMed1995

Hyperprolactinaemia in patients with pituitary adenomas. The pituitary stalk compression syndrome.

Hyperprolactinaemia, unexplained by prolactin-production of the tumour is occasionally found in patients with pituitary tumours. This secondary hyperprolactinaemia has been ascribed to a mass effect of the tumour upon the pituitary stalk, obstructing the normal inhibitory hypothalamic influence on the prolactin producing cells. In this study the adenoma volume, amount of suprasellar enlargement of the tumour and the intrasellar pressure were measured in 42 patients operated upon consecutively for pituitary tumours. Secondary hyperprolactinaemia was found in six (14%). There was no difference as regards adenoma volume, amount of suprasellar extension or intrasellar pressure between the group of patients with elevated p-prolactin versus the group with normal p-prolactin. We conclude that mechanisms other than pituitary stalk compression must be considered as the cause of secondary hyperprolactinaemia.

Adenoma↗
PubMed1994

Quantitation of peritumoural oedema and the effect of steroids using NMR-relaxation time imaging and blood-brain barrier analysis.

A new method of in vivo quantitation of peritumoural brain oedema using NMR relaxation time imaging (T1-maps) and Gd-DTPA-enhanced Blood-Tumour-Barrier (BTB) analysis is presented. The method is based on image pixel histogram analysis and a fast imaging method combined with arterial [Gd-DTPA]-measurement. The method was applied in 26 brain tumour patients, studied prior to--and 1, 3 and 7 days after initiation of dexamethasone. Oedema resorption rate following dexamethasone treatment was almost equal in glioblastomas and metastases, mean T1 being reduced by ca. 12% in 7 days. In meningiomas no significant changes in peritumoural oedema could be detected. Simultaneous BTB-analysis was obtained in 4 patients showing correlation between oedema resorption in vivo and reduction of BTB transport rate constant Ki after 7 days of steroid treatment. This method is a powerful tool in quantitation and monitoring of brain oedema in vivo, as both steroid influence on oedema resorption and on BTB-defect can be monitored simultaneously.

Blood-Brain Barrier↗
PubMed1994

Effect of stable xenon inhalation on intracranial pressure during measurement of cerebral blood flow in head injury.

Xenon-enhanced computerized tomography (CT) is well suited for measurements of cerebral blood flow (CBF) in head-injured patients. Previous studies indicated divergent results on whether inhalation of xenon may cause a clinically relevant increase in intracranial pressure (ICP). The authors employed Xe-enhanced CT/CBF measurements to study the effect of 20 minutes of inhalation of 33% xenon in oxygen on ICP, cerebral perfusion pressure (CPP), and arteriovenous oxygen difference (AVDO2) in 13 patients 3 days (mean 1 to 5 days) after severe head injury (Glasgow Coma Scale score < or = 7). The patients were moderately hyperventilated (mean PaCO2 4.3 kPa or 32.3 mm Hg). Six patients were studied before and during additional hyperventilation. All 13 patients reacted with an increase in ICP and 11 with a decrease in CPP. The mean ICP increment was 6.9 +/- 7.7 (range 2 to 17 mm Hg). The mean CPP decrement was -9.7 +/- -14.6 (range 17 to 47 mm Hg). The time course of the ICP changes indicated that ICP increased rapidly during the first 5 to 6 minutes, then declined to a plateau (peak-plateau type in four of 13 patients), remained at a plateau (plateau type in six of 13), or continued to increase in three of 13, indicating individual variance in xenon reactivity. Additional hyperventilation had no effect on the xenon-induced increments in ICP but these occurred at lower ICP and higher CPP baseline levels. The AVDO2 values, an index of flow in relation to metabolism, indicated a complex effect of xenon on CBF as well as on metabolism. This study indicates that xenon inhalation for Xe-CT CBF measurements in head-injured patients according to our protocol causes clinically significant increments in ICP and decrements in CPP. It is suggested that the effect of xenon is analogous to anesthesia induction. Individual variations were observed indicating possible individual tolerance, possible influence of type and extent of the cerebral injury, disturbances in cerebrovascular reactivity, and possible influence of medication. These effects of xenon suggest that hyperventilation should be ensured in patients with evidence of reduced compliance or high ICP. On the other hand, inhalation of stable xenon is not believed to pose a risk because no signs of cerebral oligemia or ischemia were indicated in the AVDO2 values.

Administration, Inhalation↗
PubMed1993

[Neurosurgical treatment of acromegaly].

The results of transsphenoidal surgery in 45 consecutive patients with pituitary adenoma and acromegaly are reviewed. The cure rate defined in clinical terms is specifically related to the size of the adenoma. 20 out of 21 patients with intrasellar adenomas were cured by surgery. Of 24 patients with extrasellar adenomas eight were cured and ten had improved, while six had no clinical effect of the operation. Overall 62.2% were cured, 24.4% had improved and 13.3% were unchanged. The complications were 3 patients with pituitary insufficiency, rhinoliquorrhoea successfully treated with surgery in one patient, and an internal carotid artery lesion treated with trapping without sequelae in one patient. No recurrences were observed over two years. It is concluded that treatment of acromegaly is teamwork for internists and surgeons, and that transsphenoidal pituitary surgery is at present the primary treatment of choice.

Acromegaly↗
PubMed1993

Resorption of peritumoural oedema in cerebral gliomas during dexamethasone treatment evaluated by NMR relaxation time imaging.

Peritumoural brain oedema is a prominent feature of malignant brain tumours. Glucocorticoids diminish the neurological symptoms and signs caused by the oedema and reduce the abnormally high cerebral water content. The exact mechanisms of action of the glucocorticoids are unknown. The present study investigates the influence of dexamethasone on NMR relaxation time T1 in peritumoural oedema in 13 patients with gliomas. It is shown that NMR T1 images can be used as a potent monitor of brain oedema, and that dexamethasone significantly reduces mean T1 after 1, 3, and 7 days of treatment by 2%, 6%, and 13% respectively. Using an image histogram analysis technique the term "super-oedema" was defined as the 50% of the total oedema area with the highest T1, corresponding to the highest water content. It is shown, that with this technique the treatment effect of steroids on super-oedema was a reduction of 13%, 33%, and 57% after 1, 3, and 7 days of treatment respectively. The mean change after 24 hours of treatment was statistically significant (p < 0.01). The method can be used in all situations where the anti-oedematous effect of a given treatment is to be monitored.

Aged↗
PubMed1992

[Warning bleedings prior to subarachnoid hemorrhage from intracranial, sacculate aneurysms. A consecutive, prospective study].

The incidence of warning leaks prior to subarachnoid hemorrhage was found to be 36.4% in 99 consecutive patients admitted consecutively to a neurosurgical department suffering from subarachnoid hemorrhage from ruptured intracranial, sacculate, arterial aneurysms. The durations of delays before admission to a neurosurgical department and the reasons for these, were analyzed. The patients who experienced a warning leak were in significantly poorer clinical condition than would have been the fact if they had been admitted at the time of the warning leak. It is important to bear the possibility of subarachnoid hemorrhage in mind, when a patient who has not previously complained of headache experiences violent sudden onset of headache. A program for investigation of suspected subarachnoid hemorrhage is suggested.

Adolescent↗
PubMed1992

Indomethacin (Confortid) in severe head injury and elevated intracranial pressure (ICP).

In five head-injured patients with cerebral contusion and oedema in whom it was not possible to control ICP by hyperventilation and barbiturate sedation, indomethacin (Confortid) was used as a cerebral vasoconstrictor drug. In all patients indomethacin reduced ICP to below 20 mmHg for several hours. Studies of cerebral circulation and metabolism during indomethacin treatment showed a decrease in cerebral blood flow (CBF) at 2 hours. After 7 hours, ICP remained below 20 mmHg in three patients, and these still had reduced CBF. In two patients a return of ICP and CBF to pretreatment levels was observed. In all patients indomethacin treatment was followed by a fall in rectal temperature. Outcome scaling has not yet been performed, but all patients left hospital without neurological deficits. The results suggest, that indomethacin is an alternative in the treatment of ICP-hypertension in head-injured patients.

Adult↗