Effects of haemodialysis on pulmonary clearance of Tc-99m diethylene triamine pentaacetate (DTPA)

Objectives: Hypoxaemia occurring during haemodialysis has long been known. Several mechanisms in the pathogenesis have been proposed. The present stud y was conducted to test whether changes in pulmonary alveolar permeability were among the operating mechanisms. Materials and methods Twenty haemodial ysis patients (12 male, 8 female) were included in the study. The mean age was 49 years (age range: 18-85 years). Patients with known pulmonary diseas e, current smokers and those gaining more than I kg weight during the inter dialytic period were excluded. Complete blood count, arterial blood gas ana lysis, pulmonary function tests and Tc-99m diethylene triamine pentaacetate (DTPA) inhalation scintiscan were carried out before and after haemodialys is. A bronchial provocation test was carried out after each session. A post ero-anterior chest radiogram was taken for each patient. Results: When the results before and after haemodialysis were compared, it was observed that the pH and serum bicarbonate levels, haemoglobin and haematocrit values wer e significantly higher after haemodialysis. However, the platelet count was found to be decreased significantly. Bronchial hyperreactivity, tested by metacholine, was positive in 5 of 19 patients (26%). No correlation between bronchial hyperreactivity and other factors could be identified. No signif icant difference was observed in pulmonary Tc-99m DTPA clearance after haem odialysis. All chest radiograms were interpreted to be within normal limits . Conclusions: Since we observed no hypoxaemia following haemodialysis, we cannot comment as to whether the changes in pulmonary clearance play a role in the pathogenesis of haemodialysis-associated hypoxaemia. In order to re ach reliable conclusions, additional studies are needed.