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Biomedical subjects

M H Irving

Publications and source records attributed to M H Irving.

At least 109 records · Page 6Linked to original sources

The coagulation and fibrinolytic response to splenectomy.

The responses of the coagulation and fibrinolytic systems in nine patients with Hodgkin's disease undergoing splenectomy and lymph node mapping have been compared with those in nine patients undergoing elective upper abdominal operation for benign conditions. Differences have been noted in base line levels of fibrinogen, prothrombin, partial thromboplastin time and euglobulin lysis time. Platelet count increases were exaggerated following splenectomy, but other parameters of coagulation activity behaved similarly in the two groups. There is no evidence from this study to support the suggestion that blood coagulability is increased more markedly following splenectomy than it is after other upper abdominal operations.

Abdomen↗

The influence of beta-adrenergic blockade upon baseline blood coagulation and fibrinolytic activity and upon the responses to venous occlusion.

Twenty volunteers were assessed for baseline coagulation (Thrombelastography, Factor VIII and platelet count) and fibrinolytic (Euglobulin Lysis Time and Fibrin(ogen) Degradation Products) activity two hours after ingestion of 60 mgm propranolol or an identical placebo administered on a double blind basis. The responses of these parameters to a fifteen minute period of venous occlusion was also assessed. Beta adrenergic blockade reduced baseline FDP titres but did not affect other parameters, nor the local response to venous occlusion. During occlusion no significant change in coagulation activity could be detected in the non-occluded arm, but a small but statistically significant shortening of ELT was observed. Since this effect was prevented by propranolol it is probably mediated through adrenergic mechanisms. Adrenergic stimuli appear to influence episodes of coagulation and fibrinolysis during everyday activity, but do not contribute to baseline levels of coagulation or fibrinolytic function.

Adult↗

The adrenergic response to cardiopulmonary bypass.

12 out of 13 patients who underwent cardiac surgery requiring extracorporeal circulation survived the operation. Arterial and venous catecholamines were measured throughout the operation. Larges rises in catecholamine levels were not seen although significant changes did occur in arteriovenous differences and also between samples at certain points in the operation. These facts do not agree with Lillehei's findings (3) and may reflect improvements in surgical technique, anaesthesia and the reduced time on bypass. However the lack of an overall measurable adrenergic response in terms of plasma catecholamine levels does agree with similar findings after open heart surgery (4) and during other surgical procedures (5).

Adolescent↗

Changes in blood catecholamine levels and blood coagulation and fibrinolytic activity in response to graded exercise in man.

Measurements of catecholamines, fibrinogen, factor VIII, thrombelastography, euglobulin lysis time and platelet adhesiveness have been carried out on venous blood obtained from normal males exposed to exercise on a bicycle ergometer at various work loads. Significant increases in adrenaline, factor VIII and fibrinogen were found only after exercise to exhaustion at 1500 kpm min-1 whereas the euglobulin lysis time was inversely proportional to the excercise load. There was no change in platelet adhesiveness. These findings support the results of studies using adrenaline infusions or adrenergic blockade which suggest that stress-induced increases in factor VIII are mediated via adrenergic stimulation but that activation of fibrinolysis is not dependent on adrenaline.

Adult↗

Surgical pathology of the spleen.

The indications for splenectomy in haematological and myeloproliferative disorders are now wider than before. An increased understanding of the concept of hypersplenism and a developing appreciation of the value of splenectomy in chronic leukaemia has been partially responsible for the increase. The principal factor, however, has been the advent of routine splenectomy as an integral part of the diagnostic process in Hodgkin's disease. This paper discusses these indications and their surgical pathology.

Hodgkin Disease↗

Adrenergic, coagulation, and fibrinolytic responses to heat.

Two groups of volunteers were exposed to heat in a sauna bath-one group for 10 minutes and the other for 15. There was no change in plasma adrenaline concentration until the subjects emerged from the sauna bath, when there was a slight increase in concentration. Factor VIII and thrombo-elastograph patterns did not change but marked activation of fibrinolysis was stimulated by exposure to heat. These findings support the concept that fibrinolysis is not mediated by direct adrenergic activity.

Adult↗