The haemolytic complications of prosthetic heart valve replacement

Slater, Stefan Daniel (1974) The haemolytic complications of prosthetic heart valve replacement. MD thesis, University of Glasgow.

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Abstract

A study of the haemolytic complications of prosthetic heart valve replacement forms the subject of this thesis. A chronic traumatic intra-vascular haemolysis is the principal complication and its investigation constitutes the major part of this study. The history of haemolysis with intrcardiac prosthetio devices extends over 20 years and is outlined, and haemolysis is patients with valvular heart disease without prostheses is discussed. The incidence of traumatic haemolysis and haemolytic anaemia, their diagnosis, pathogenesis, complications, and treatment are reviewed in detail. There are four basic objectives to this study. 1. To assess the relative value of different testes employed in the diagnosis of intravascular haemolysis, with particular reference to serum lactate dehydrogenase levels the urinary heemosiderin test, and the evaluation of red cell morphology a. To compare and contrast the incidence and severity of traumatic haemolysis with different prosthetic valve types and to attempt to identify factors of aetiological importance 3. To examine potential complications of chronic intravascular haemolysis, including the assessment of urinary iron losses and accompanying iron deficiency, the effect of renal haemosiderosis upon renal function, and the possible potentiating effect on the thrembo-emoolic complioatione of the release of red cell haemolysate, 4. To investigate immune haemolytic factors, inciting the possibility of an autoimmune component to the traumatic haemolysis, and the frequency with which "blood group opeoific alloantibody develop as a consequence of the considerable blood transfusion required at valve replacement operations From this study X have obtained the following results and conclusions 1. Serum lactate dehydrogenase levels, known to be a sensitive index of intravascular haemolysis, wore found to correlate inversely and significantly with the half-life of 51Cr-labelled autologous red cells Urinary haemosiderin was found to the an equally sensitive indicator of chronic intravascular haemolysis and its degree relates directly to the severity of haemolysis. It is therefore a useful and staple screening procedure in the long-terra care of patients with prosthetic valves. She degree of ved, cell fragmentation and distortion was also found to relate directly to the severity of haemolysis. A lees subjective and more accurate counting procedure for the enumeration of those abnormal forma was devised, with which it was determined that minor yet abnormal degrees of red cell fragmentation might frequently go unrecognised on routine film inspection, and that even the observation of only a very occasional fragmented or distorted red cell should he regarded as likely evidence of haemolysis, With a normal fragment count, however, the presence of a traumatic haemolysis cannot he excluded. The various types of abnormal red cells encountered in these patients have been classified and illustrated. Of these various types only the number of triangular shaped cells appeared to relate to the degree of haemolysis and were extremely uncommon in normal blood films. They way, therefore, have diagnostic value. It is also proposed that many of the different appearances exhibited are the result of sequential changes in morphology following trauma. She reticulocyte count and estimation of soruw bilirubin and urinary urobilinogen levels were found to be of very limited value in the detection of intravascular haemolysis and assessment of its severity. (Abstract shortened by ProQuest.).

Item Type: Thesis (MD)
Qualification Level: Doctoral
Additional Information: Adviser: G A McDonald
Keywords: Medicine
Date of Award: 1974
Depositing User: Enlighten Team
Unique ID: glathesis:1974-73381
Copyright: Copyright of this thesis is held by the author.
Date Deposited: 14 Jun 2019 08:56
Last Modified: 14 Jun 2019 08:56
URI: http://theses.gla.ac.uk/id/eprint/73381

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