Iraqi Postgraduate Medical Journal

Abstract

ABSTRACT: BACKGROUND: An arteriovenous fistula must be able to sustain the flow demands of the hemodialysis machine; the flow rate in the fistula only has to be marginally greater than the demands of the blood pump. So fistula flow should be in the range of 600 to 700 mL/min. Overflow occurs when flow rate exceeds 20% of cardiac output. OBJECTIVE: Evaluation of arteriovenous fistula flow rate and post fistula venous diameter in patients on regular hemodialysis to highlight the prevalence of overflow fistula and its relation to gender, co-morbidities, signs and symptoms. PATIENTS AND METHODS: The measurements of fistula flow rate and post fistula venous diameter in a randomly selected sample of 43 hemodialysis patients (all are bracheocephalic AV-fistula) in the department of dialysis in al-Yarmouk Teaching Hospital in the period from the 1st of August 2010 till the 28th of February 2011. Statistical analysis using Chi-square test and Pearson correlation has been done via SPSS software version 17. RESULTS: From the 43 patients enrolled in the study, 31(72%) patients have a fistula flow rate over 1300 mL/min, overflow group; 12 (28%) patients have a flow rates within 1000 ± 300 mL/min, optimal flow group and none has a fistula flow rate less than 700 mL/min. There is a significant association between overflow fistula with (hypertension, the presence of peripheral cyanosis in the fistula corresponding hand, the occurrence of numbness in the fistula corresponding hand and the occurrence of dizziness during hemodialysis) and a strong linear correlation between the measurements of post fistula venous diameter and corresponding fistula flow rates, Pearson correlation coefficient (r) of +0.8005. CONCLUSION: Our study shows a high prevalence of overflow fistula in the patient sample, and this high flow rate is associated with significant complications