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Biomedical subjects

T Lundar

Publications and source records attributed to T Lundar.

63 records · Page 4Linked to original sources
PubMed1983

Total creatine kinase activity in cerebrospinal fluid as an indicator of brain damage during open-heart surgery.

In a selected series of 33 patients undergoing open-heart surgery, the creatine kinase (CK) activity in cerebrospinal fluid (CSF) was compared with the clinical results in regard to the central nervous system. The level of CK activity in CSF showed correlation with the degree of irreversible neuronal damage. Determination of CK in CSF may thus be of prognostic value in these patients. Caution is essential, however, in the setting of strict limits above which return to normal or acceptable quality of life is not to be expected.

Brain Damage, Chronic↗
PubMed1983

The clinical significance of changes in cerebral perfusion pressure during open-heart surgery.

In 34 high-risk patients, the intracranial epidural pressure (EDP) and the cerebral perfusion pressure (CPP) were monitored in connection with open-heart surgery. The findings were clinically evaluated, with special attention to affection of the central nervous system. Reduction of EDP to 10-30 mmHg for periods up to 10 min at the start of extracorporeal circulation and transient rise of EDP in the early postoperative period were relatively well tolerated. Late postoperative EDP rise, on the other hand, denoted an unfavourable trend, associated with permanent cerebral damage. Mannitol and/or barbiturates are indicated when an early rise in postoperative EDP persists or a late rise occurs. Covariation of EDP and arterial blood pressure (BP) should be regarded as a warning sign, especially if it is pronounced or appears during the postoperative course. In such conditions it seems important to stabilize the CPP by reducing a high EDP and by careful management of BP variations, i.e. with use of vasopressors. Postoperative epileptiform seizures seem to be prognostically unfavourable.

Adolescent↗
PubMed1983

Induced barbiturate coma: methods for evaluation of patients.

Seven patients treated with deep sustained barbiturate narcosis to protect the brain and control intracranial hypertension underwent extensive monitoring. The epidural intracranial pressure (EDP) and arterial blood pressure (BP) were recorded continuously; serial records of the EEG, somatosensory evoked potential (SEP) and internal carotid artery (ICA) flow velocities by pulsed Doppler technique were obtained. Serum barbiturate levels leading to full suppression of the EEG did not change the central conduction time nor the configuration of the evoked responses. Monitoring the intracranial pressure (ICP), BP, and thereby, the cerebral perfusion pressure (CPP) gave valuable information on the patients' state and served as a guide for dosage and timing of barbiturate therapy, and facilitated supervision of adequate ventilation. Recording of EEG and SEP, monitoring of the CPP and ICA Doppler investigation offer prognostic information in these cases. When clinical deterioration occurs, these methods can predict and, in combination, give ample evidence for development of brain tamponade. Premature as well as unnecessarily deferred 4-vessel angiography, therefore, can be avoided.

Barbiturates↗
PubMed1982

Aspects of cerebral perfusion in open-heart surgery.

A selected series of 25 patients undergoing open-heart surgery were subjected to continuous monitoring of arterial blood pressure (BP), central venous pressure (CVP) and intracranial epidural pressure (EDP). This gave continuous information on the cerebral perfusion pressure (CPP = BP-EDP). In all patients the start of the extracorporeal perfusion caused a rapid fall in CPP (30 mmHg or less in 22 patients, less than 10 mmHg in 5 patients). The combination of grave systemic hypotension and increased EDP contributed to these low CPP states, which varied in duration from 2 to 15 min. Spontaneous, as well as vasopressor-induced BP recovery was accompanied by a concomitant increase in EDP in 15 patients. This prolonged the low CPP state, making an evaluation of CPP from BP alone misleading under such conditions. Increasing EDP secondary to a rise in BP was also observed during termination of the extracorporeal circulation, particularly in 6 patients requiring an intra-aortic balloon pump in addition to large doses of vasopressors to obtain an acceptable BP. An increase in CVP to levels above EDP is transmitted intracranially, thus reducing the CPP. The recordings may improve insight into pathogenic mechanisms leading to harmful effects on the brain in connection with open-heart surgery.

Blood Pressure↗
PubMed1981

The effect of haemodilution on arterial blood pressure, central venous pressure, intracranial and intra-ocular pressures in pigs.

During the open-heart surgery, haemodilution is performed before extracorporeal circulation is started by the sampling of autologous blood and substituting an electrolyte solution. Following extracorporeal circulation, first the machine-blood and then the autologous blood is reinfused. The haemodilution and reinfusion procedures lead to alterations in blood osmolality and tissue fluid distribution, initiating changes in arterial blood pressure, central venous pressure, intracranial and intraocular pressures. These changes were studied in pigs. It is believed that these potentially hazardous pressure alterations can be minimized through proper handling of the procedure. This study presents some of the mechanisms involved.

Animals↗
PubMed1979

Cerebral arteriovenous malformations; results of microsurgical management.

A series of 63 patients with cerebral arteriovenous malformation (AVM) operated on during an eight-year period is presented. Indications for surgery and the timing of operation are discussed. Monitoring of epidural pressure was of help in assessing the intracranial pressure state, which is important in patient management in the acute stage, in timing of surgery, and in postoperative supervision. The operative mortality was one patient (1.6%). Two patients died due to incomplete resection and late rebleeding two years after operation. Among the others the overall result of surgery was good with respect to neurological deficit and working capacity.

Adolescent↗
PubMed1977

A case of chronic demyelinating polyneuropathy resembling the Guillain-Barré syndrome.

A case of demyelinating polyneuropathy is reported which was clinically and pathologically indistinguishable from the Guillain-Barré syndrome, with the exception that the symptoms progressed steadily for 7 months. Pathologically, the peripheral nerves and intraspinal roots showed selective demyelination with axonal sparing and patchy mononuclear inflammation. The posterior columns of the spinal cord also showed selective demyelination with axonal sparing. The simultaneous destruction of central and peripheral myelin is discussed in relation to the immune theory for the Guillain-Barré syndrome. Numerous anterior horn cells showed severe chromatolysis although there was little axon loss. It is suggested that chromatolysis may occur after severe and longstanding demyelination.

Demyelinating Diseases↗
PubMedDate not supplied

Variations in middle cerebral artery blood flow investigated with noninvasive transcranial blood velocity measurements.

Observations on blood velocity in the middle cerebral artery using transcranial Doppler ultrasound and on the ipsilateral internal carotid artery flow volume were obtained during periods of transient, rapid blood flow variations in 7 patients. Five patients were investigated after carotid endarterectomy. A further 2 patients having staged carotid endarterectomy and open heart surgery were investigated during nonpulsatile cardiopulmonary bypass. The patient selection permitted the assumption that middle cerebral artery flow remained proportional to internal carotid artery flow. The integrated time-mean values from consecutive 5-second periods were computed. The arithmetic mean internal carotid artery flow varied from 167 to 399 ml/min in individual patients, with individual ranges between +/- 15% and +/- 35% of the mean flow. The mean middle cerebral artery blood velocity varied from 32 to 78 cm/sec. The relation between flow volume and blood velocity was nearly linear under these conditions. Normalization of the data as percent of the individual arithmetic means permitted a composite analysis of data from all patients. Linear regression of normalized blood velocity (V') on normalized flow volume (Q') showed V' = 1.05 Q' - 5.08 (r2 = 0.898).

Blood Flow Velocity↗