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Biomedical subjects

S E Gisvold

Publications and source records attributed to S E Gisvold.

At least 19 recordsLinked to original sources
PubMed1995

Alterations in perivascular dilatory neuropeptides (CGRP, SP, VIP) in the external jugular vein and in the cerebrospinal fluid following subarachnoid haemorrhage in man.

A possible involvement of perivascular vasodilatory neuropeptides in subarachnoid haemorrhage (SAH) has been evaluated in man by measuring the levels of calcitonin gene related peptide (CGRP)-, substance P (SP)- and vasoactive intestinal peptide (VIP)-like immunoreactivity (LI) in the cranial venous outflow and in CSF in 34 patients admitted to the hospital after an acute SAH. After operation with aneurysm clipping and nimodipine treatment, blood samples were taken from the external jugular vein (EJV) or cerebrospinal fluid (CSF) and analysed for neuropeptide levels with specific radioimmuno assays (RIA) during the postoperative course. The degree of vasoconstriction in the patients was monitored with Doppler ultrasound recordings bilaterally from the middle cerebral (MCA) and internal carotid arteries (ICA) following the EJV blood sampling every second day. The mean value of all CGRP-LI measurements in EJV during the entire course of SAH (n = 20) revealed a significantly higher level as compared to controls. The highest CGRP-LI levels were found in patients with the highest velocity index values (vasospasm). The relationship Vmean MCA/Vmean ICA was used as an index of vasoconstriction. In patients with MCA aneurysms (n = 10), a significant correlation (r = 0.65, p < 0.05) was found between the vasospasm index and CGRP-LI levels. There were no changes observed in the SP- and VIP-LI levels. Alterations in cerebrovascular tone induced by changing arterial CO2 tension or lowering of blood pressure (ketanserin infusion test) did not alter the levels of the perivascular peptides in the EJV. In addition, CGRP-, SP-, VIP- and neuropeptide Y (NPY)-LI were analysed in CSF in the post-operative course after subarachnoid haemorrhage (SAH) in 14 patients. The CSF VIP-LI was lower in SAH than in control (p < 0.05). The CGRP-LI level was measurable in SAH CSF but not in CSF of controls. In individual patients with marked vasoconstriction increased levels of CGRP-LI (up to 14 pmol/L) and NPY-LI (up to 232 pmol/L) were observed. The results of this study are in support of our hypothesis that there is an involvement of the sensory peptide CGRP in a dynamic reflex aimed at counterbalancing vasoconstriction in SAH.

Adult↗
PubMed1994

Calcitonin gene-related peptide (human alpha-CGRP) counteracts vasoconstriction in human subarachnoid haemorrhage.

Calcitonin gene-related peptide (CGRP) is a neuropeptide co-stored with tachykinins (substance P, neurokinin A) in cerebrovascular sensory fibers in the trigeminal ganglion. Preceding studies on subarachnoid hemorrhage (SAH) revealed that an enhanced release of CGRP resulted in the selective loss of perivascular CGRP. Therefore, the present study was designed to evaluate the effects of intravenous administration of human alpha-CGRP on cerebral vasoconstriction in the postoperative course after SAH in 5 patients (8 infusions). Cerebral vasoconstriction was evaluated with transcranial Doppler sonography. The increase in the relationship between middle cerebral artery (MCA) velocity and internal carotid artery (ICA) velocity (the hemodynamic index) was used as an indicator of vasoconstriction and compared to the contralateral side. A significant reduction was found in the hemodynamic index during the CGRP infusion (4.3 +/- 0.5, P < 0.05) as to compared to before infusion (6.2 +/- 0.5). There was no measurable change in the hemodynamic index on the contralateral side. No significant change was observed in pulsatility index, blood pressure or consciousness during the peptide infusion. A significant increase in heart rate was observed during the infusion as compared to before and after infusion (90 +/- 4 vs. 76 +/- 5). Cardiac ultrasound data indicated a mean cardiac output increase of 1.9 liter/min, and a mean decrease in total peripheral resistance of 538 dynes s/cm5. The results obtained show that infusion of human alpha-CGRP may induce normalisation of cerebrovascular tone in SAH.

Adult↗
PubMed1994

Thoracic epidural analgesia in aortocoronary bypass surgery. I: Haemodynamic effects.

Tachycardia and hypertension may cause myocardial ischaemia in patients with coronary heart disease going through major surgery. Thoracic epidural analgesia (TEA) has been reported to be beneficial in this situation. The haemodynamic effects of TEA in aortocoronary bypass surgery were investigated in 30 male patients < 65 years old and with ejection fraction > 0.5. They were randomized into 3 groups: the high dose fentanyl (HF) group receiving high-dose fentanyl (55 micrograms.kg-1) anaesthesia, the HF+TEA group receiving the same fentanyl dose+TEA with 10 ml bupivacaine 5 mg.ml-1 followed by 4 ml every hour, and the low dose fentanyl (LF) + TEA group receiving low-dose fentanyl (15 micrograms.kg-1) anaesthesia+TEA. Haemodynamic parameters, the use of vasoactive and inotropic drugs and fluid balance were followed during the operation and for 20 h postoperatively. Before bypass the only significant difference between groups was a higher mean pulmonary arterial pressure in the HF+TEA group and a lower systemic vascular resistance (SVR) in the LF+TEA group, both compared to the HF group. 89% of epidural group patients needed small doses of ephedrine whereas more HF group patients were given nitroglycerine. During bypass SVR and mean arterial pressure (MAP) were significantly higher and pump flow lower in the HF group compared to the LF+TEA group. More ketanserin to HF group patients and methoxamine to epidural group patients were given. After bypass heart rate increased in all groups. Lower MAP 0.5 h after bypass and higher filling pressures in the early post bypass period in the epidural groups, most pronounced in the HF+TEA group, were noted.(ABSTRACT TRUNCATED AT 250 WORDS)

Analgesia, Epidural↗
PubMed1994

Thoracic epidural analgesia in aortocoronary bypass surgery. II: Effects on the endocrine metabolic response.

Thoracic epidural analgesia (TEA) may offer haemodynamic benefits for patients with coronary heart disease going through major surgery. This may-in part-be secondary to an effect on the endocrine and metabolic response to surgery. We therefore investigated the effect of TEA on the endocrine metabolic response to aortocoronary bypass surgery (ACBS). Thirty male patients (age < 65 years, ejection fraction > 0.5) were randomized into 3 groups; the HF group receiving a high dose fentanyl (55 micrograms.kg-1) anaesthesia, the HF+TEA group with the same fentanyl dose+TEA with 10 ml bupivacain 5 mg.ml-1, followed by 4 ml every hour, and the LF+TEA group receiving fentanyl 15 micrograms.kg-1 + TEA. Adrenalin, noradrenalin, systemic vascular resistance (SVR), glucose, cortisol, lactate and free fatty acids were followed during the operation and for 20 h postoperatively. A significant increase in adrenalin, noradrenalin and SVR was found in the HF group whereas this increase was blocked in both epidural groups. An increase in glucose and cortisol was noticed in all groups, but the increase was delayed in the epidural groups. Our results suggest that a more effective blockade of the stress response during ACBS is obtained when TEA is added to general anaesthesia than with high dose fentanyl anaesthesia alone.

Analgesia, Epidural↗
PubMed1993

The influence of thoracic epidural analgesia alone and in combination with general anesthesia on cardiovascular function and myocardial metabolism in patients receiving beta-adrenergic blockers.

Thoracic epidural analgesia combined with chronic beta-adrenergic blocker medication may cause cardiac depression. We investigated the cardiovascular and myocardial metabolic effects of a T1-T12 epidural block in 18 patients (age < 65 yr, ejection fraction > 0.5), receiving chronic beta-adrenergic blocker medication and scheduled for aortocoronary bypass surgery. After randomization into a light or deeper general anesthetic group, the cardiovascular and myocardial metabolic effects of a subsequent general anesthesia induction were investigated. Thoracic epidural analgesia induced a moderate decrease in mean arterial pressure, coronary perfusion pressure, free fatty acids, and myocardial consumption of free fatty acids. General anesthesia with thiopental (2-4 mg/kg) and a low fentanyl dose (5 micrograms/kg) increased heart rate, coronary perfusion pressure, and coronary vascular resistance, whereas mean pulmonary arterial pressure and pulmonary capillary wedge pressure decreased. After thiopental (2-4 mg/kg) and a high fentanyl dose (30 micrograms/kg), mean arterial pressure and left ventricular stroke work index decreased. We conclude that a T1-T12 epidural block in well sedated, beta-adrenergic blocked patients does not induce clinically significant cardiovascular effects. Induction of general anesthesia was well tolerated, but the light general anesthetic could not prevent an increase in heart rate and coronary vascular resistance, whereas the deeper anesthetic induced slight myocardial depression. No effect on the atrioventricular conduction, as measured by the PQ-time, was noted.

Adrenergic beta-Antagonists↗
PubMed1992

Hyperglycemia in global cerebral ischemia and reperfusion: a 31-phosphorous NMR spectroscopy study in rats.

31-phosphorous magnetic resonance spectroscopy was used in a rat model of 10 min severe incomplete forebrain ischemia (two-vessel occlusion with hypotension) to assess the effect of hyperglycemia on intracellular pH and high energy phosphates during ischemia and early reperfusion. One group (n = 8) with preischemic hyperglycemia (serum glucose 20 mmol.l-1) showed an increased intracellular acidosis (pH 6.35) during ischemia compared to 6.55 in the normoglycemic control group (n = 7, P less than 0.001), but the recovery of phosphocreatine and ATP in early reperfusion was the same in the two groups. Another group (n = 7) was normoglycemic during ischemia, but received an i.v. bolus of glucose during the first minute of reperfusion. In this group the recovery of intracellular pH in early reperfusion was slower than in the control group (0.034 +/- 0.006 pH units per minute compared to 0.052 +/- 0.11 in the controls, +/- s.d. and P less than 0.01).

Acidosis↗
PubMed1992

The effects of brain temperature on temporary global ischaemia in rat brain. A 31-phosphorous NMR spectroscopy study.

31-Phosphorus magnetic resonance spectroscopy was used in a rat model of 10 min severe incomplete forebrain ischaemia (2-vessel occlusion with hypotension) to assess the effect of mild brain hypo- and hyperthermia (+/- 2 degrees C) on intracellular pH and high energy phosphates. In three experimental groups intracerebral temperature was maintained at levels of 34, 36 and 38 degrees C during ischaemia and early reperfusion. The steady level of intracellular pH during ischaemia was 6.63, 6.58 and 6.53 in the 34, 36, and 38 degrees C groups, respectively. The rate of initial recovery of intracellular pH in reperfusion was 0.046 +/- 0.012 pH units per min (+/- s.d.) in the 36 degrees C group compared to 0.056 +/- 0.010 (+/- s.d., P less than 0.05) in the 34 degrees C group and 0.032 +/- 0.009 (+/- s.d., P less than 0.01) in the 38 degrees C group. The recovery in early reperfusion of phosphocreatine and ATP was slower in the 38 degrees C group compared to the other groups. The findings were consistent with recent studies, suggesting that even mild hypothermia may afford protection to the ischaemic brain, and furthermore indicate that mild hyperthermia as fever or even subfebricity may be deleterious for the outcome in stroke patients.

Adenosine Triphosphate↗
PubMed1991

[Quality assurance of technical medical equipment. Report from a research department].

Det norske Veritas has been engaged by the Ministry of health and social affairs to establish a system to improve the use and maintenance of technical equipment in hospitals. The system is being tested in several hospital departments in Norway, among them the Department of anaesthesia at the Regional Hospital in Trondheim (Regionsykehuset). This article presents preliminary experiences. The system is complicated, and the manuals developed by Veritas are of little help to users at the clinic. The system would benefit from being made more simple, more directly problem oriented and more adjusted to the users' needs.

Anesthesia Department, Hospital↗
PubMed1990

[Causes and risk factors of intraoperative anesthesia complications. A prospective study of 14,735 anesthesias].

Identification of risk factors is an essential part of our efforts to minimize problems during anesthesia. 14,735 patients were included in a prospective study in order to assess the magnitude of risk and identify risk factors. The rate of complications increased substantially after the age of 40, due mainly to a large number of patients with poor preoperative physical condition. High age in itself was not associated with increased risk of complications. Contrary to former belief, the maintenance period of anesthesia does represent a considerable risk of complications requiring emergency intervention by an anesthesiologist. The complications were related to the conduct of anaesthesia in 70% of the total number of cases and to poor physical status and the surgery in 30%. However, poor physical condition and the surgery were responsible for 50% of the very serious complications and for all the four deaths on the table. The results of the survey confirm that thorough preoperative preparation of the patient is extremely important in order to reduce intraoperative risk, especially in emergency surgery.

Adolescent↗
PubMed1990

[Registration of problems during anesthesia. Analysis of risk factors and quality control].

Society continues to increase its demands on the medical profession in regard to quality. We believe this situation should be met by a more systematic approach to risk evaluation and quality assessment of our work. We report an attempt to establish a routine system for recording complications during anesthesia. We included all 14,735 patients who were anesthetized during one year. Data on preoperative disease, type of anesthesia and operation, and problems encountered during anesthesia were recorded on the routine anesthesia chart. An arbitrary scale from 1-3 indicated the severity of the problem. Postoperatively, data from each patient were fed into a personal computer. The system is feasible in a busy clinical setting. Key problems are work discipline, exact criteria for complications, and quality control of anesthesia charts. 655 problems were recorded in 599 patients. 80 problems were very serious. Problems such as drop in blood pressure, intubation, laryngeal spasm and cardiac arrhythmias dominated. Such registration increases awareness for the safety of the patients, and enables us to assess the risk and evaluate the quality of our work. The system is now an integral part of the department's routine.

Adolescent↗
PubMed1990

Changes in the levels of neuropeptide Y-LI in the external jugular vein in connection with vasoconstriction following subarachnoid haemorrhage in man. Involvement of sympathetic neuropeptide Y in cerebral vasospasm.

NPY is a putative neurotransmitter mainly co-localized with noradrenaline in sympathetic fibers which innervate the cerebral vasculature. The origin of most of the perivascular NPY fibers seems to be in the superior cervical ganglion. To investigate involvement of Neuropeptide Y (NPY) mechanisms in subarachnoid haemorrhage (SAH), twenty patients with SAH were investigated. NPY-LI (-like immunoreactivity) levels in the external jugular vein were assessed using radioimmunoassay in blood samples collected post-operatively (or after SAH in non-surgical patients) on days 1,2,3, 5,7 and 9. These levels were compared with the clinical course and blood flow velocity changes monitored with ultrasonic Doppler equipment from both middle cerebral arteries (MCA) and both internal carotid arteries (ICA). Compared to NPY-LI levels in 14 controls (mean 116 +/- 3 pmol/1), increased levels (up to 253 pmol/l) and a close relationship between velocities and NPY-LI levels were found in a subpopulation of the SAH patients. When comparing the mean haemodynamic index (V MCA/ipsilateral V ICA) and mean NPY-LI levels in each of the 20 patients, a correlation of r = 0.75, p = 0.0001 was found. Increased NPY-LI were found (131 +/- 8 pmol/l) when simultaneous Doppler velocity recordings showed vasoconstriction (Haemodynamic index greater than 5) compared with samples taken when the haemodynamic index was less than 5, p less than 0.05. When MCA velocity exceeded 120 cm/sec. increased levels were found (129 +/- 9 pmol/l) compared with the conditions when MCA velocity was less than 120 cm/sec (113 +/- 5 pmol/l), p = 0.06. The results indicate a possible NPY involvement in cerebral vasoconstriction after SAH.

Adult↗
PubMed1990

31 phosphorous nuclear magnetic resonance spectroscopy of rat brain with temporary global cerebral ischemia--methodology.

31 P Magnetic Resonance Spectroscopy offers a technique for measuring intracellular pH and the high energy phosphates Phosphocreatine (PCr) and ATP in vivo. The 2-vessel occlusion model of temporary global cerebral ischaemia in the rat was adopted in this technique. This approach gave reliable results for intracellular pH and valuable information about PCr and ATP with an accurate time resolution for the changes during ischaemia and early reperfusion. The method may be a useful tool to evaluate possible benefits from different kinds of pre- and post ischaemic drug intervention.

Adenosine Triphosphate↗
PubMed1990

Atrial natriuretic peptide-LI following subarachnoid haemorrhage in man.

Atrial natriuretic peptide-like immunoreactivity (ANP-LI) was measured in plasma from the external jugular vein (EJV) in the postoperative course of 11 patients with aneurysmal subarachnoid haemorrhage. Samples were taken on day, 1, 2, 3, 5, 7 and 9 after operation and ANP-LI levels were determined using radioimmunoassay. Ten healthy volunteers were investigated with one EJV plasma sample. Comparing the whole group of SAH patients with the control group, no significant differences in ANP-LI levels were found. In one patient very high ANP-LI levels were found together with high mean plasma sodium levels and high urine sodium excretion. This suggests that there is no general correlation between plasma ANP-LI and SAH; in occasional patients such a correlation may be secondary to changes in plasma sodium levels.

Adult↗
PubMed1990

The NMDA antagonist MK-801 improved metabolic recovery after 10 minutes global cerebral ischaemia in rats measured with 31 phosphorous magnetic resonance spectroscopy.

The blockade of postsynaptic receptors for excitatory amino acids is a promising new field for the possible treatment of cerebral ischaemia. The most important receptor seems to be the N-methyl-D-aspartate (NMDA) subtype of the glutamate receptors and MK-801 is a potent non-competitive antagonist to the NMDA receptor. 31P NMR Spectroscopy was used to measure the recovery of intracellular pH and the high energy phosphates Phosphocreatine (PCr) and ATP after ten minutes of temporary global cerebral ischaemia in the rat. Cerebral ischaemia was obtained by combining bilateral carotid ligation and systemic hypotension (2 vessel occlusion model). Two intervention groups with intravenous injection of MK-801 in doses of 0.25 mg/kg and 0.5 mg/kg 15 minutes before onset of ischaemia were compared to a control group. Both intervention groups showed a more rapid recovery of PCr and ATP than the control group, but there were no significant differences for intracellular pH.

Adenosine Triphosphate↗
PubMed1990

Calcitonin gene-related peptide-LI in subarachnoid haemorrhage in man. Signs of activation of the trigemino-cerebrovascular system?

Calcitonin gene-related peptide (CGRP) is a neurotransmitter candidate together with the tachykinins in sensory fibres in the cerebral vasculature, with possible vasodilating properties. The origin of most of the CGRP-immunoreactive cerebrovascular nerve fibres seems to be the trigeminal ganglion. Experimentally produced vasoconstriction in cats after lesions of the trigeminal ganglion have shown marked prolonged constriction compared to controls. The possible involvement of the trigemino-cerebrovascular system as a defence system, with CGRP probably being the more potent vasodilatator, was investigated in 12 patients with subarachnoid haemorrhage (SAH). After operation with clipping of the aneurysm and treatment according to department policy, blood samples were taken from the external jugular vein on postoperative days 1, 2, 3, 5, 7, 9, frozen and analysed (radioimmunoassay) for CGRP-LI (-like immunoreactivity) levels. The patients were monitored with Doppler recordings from the middle cerebral arteries (MCA) and internal carotid arteries (ICA) following blood sampling. The relationship Vmean MCA/V mean ICA was used as an index of vasospasm. The highest CGRP-LI levels were found in the patient with highest velocities/index values. In patients with MCA aneurysms (n = 7), a correlation of r = 0.61 was found between the index and CGRP-LI levels. However, significant changes in the group as a whole was not found. The possible involvement of the trigemino-cerebrovascular system in SAH is discussed.

Adult↗