Degree Type

Dissertation

Date of Award

1987

Degree Name

Doctor of Philosophy

Department

Veterinary Physiology and Pharmacology

Abstract

The cardiopulmonary functions were evaluated in thirty one mature healthy dogs, during the surgical procedure of total hip arthroplasty (THA). THA was performed with polymethylmethacrylate bone cement (PMM) in the first group (n = 9), and in the second group (n = 8) THA was performed utilizing play dough (PD) as a control substance for PMM. In the third group (n = 8), sham THA surgery was performed (SS), and the fourth group (n = 6) served as a control (C). Systemic and pulmonary hemodynamic parameters, lung mechanics, gas exchange parameters, and blood gases were recorded at different stages of the procedure of THA. At the end of the experiment lung sections were submitted for histopathological and ultrastructural studies. The lungs were lavaged for biochemical evaluation of the surfactant system. Pulmonary fat emboli were consistent findings following the procedure of THA, and they were significantly higher in PMM group. Pulmonary microvascular damage was more pronounced in PMM group. Hemodynamic changes, characterized by venous pooling, and including significant drop in cardiac output, stroke volume, and cardiac index, as well as significant elevation in systemic and pulmonary vascular resistance, were observed in PMM group, however, they were well tolerated by young healthy dogs. The increases in respiratory rate, airway resistance, and work of breathing in PMM group, were within the normal limits of the animal's physiological tolerance. The changes in such respiratory parameters could result from pulmonary vascular obstruction. The hemodynamic changes in PMM group probably resulted from a diminished venous return due to venous pooling, and partially, due to pulmonary vascular obstruction with fat. The proposed change in the venous tone may be attributed to possible release of tissue thromboplastic products during the procedure, as well as endogenous compounds from embolized lungs;The data also indicated that PMM does not appear to have any direct significant toxicity on the cardiopulmonary functions of healthy, young dogs. Preoperative evaluations of the cardiopulmonary functions as well as intraoperative fluid loading are recommended for THA in the dog.

DOI

https://doi.org/10.31274/rtd-180813-10607

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/

Copyright Owner

Ayaad Wassef Assaad

Language

en

Proquest ID

AAI8721869

File Format

application/pdf

File Size

177 pages

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