Influence of Dry Weight Adjustment by Inferior Vena Cava Sonography in Hemodialysis Patients on Quality of Life During Treatment

Introduction Patients with end-stage renal disease (ESRD) cannot regulate their fluid balance, and are dependent on dialysis for fluid removal. Fluid removal is dependent upon estimation of dry weight. Dry weight is defined as the post-dialysis weight under which a patient suffers (more often than not) from symptoms of hypotension. Today, clinical estimation of dry weight is based on physical examination. This method is inaccurate, and many patients suffer from the consequences of over- or under-estimation of their dry weight. Overestimation leads to hypertension, edema and pulmonary congestion, cardiac hypertrophy and failure. Underestimation results in chronic dehydration, hypotension, dizziness, muscle spasms, gastrointestinal disturbances, tinnitus and shock. Both over- and underestimation diminish quality of life. One of the methods proposed as objective estimators of hydration status is sonographic measurement of the inferior vena cava diameter (IVCD). Cheriex et al have determined that IVCD correlates with right atrial filling, and suggested that IVCD above 11.5 mm/m2 indicates hypervolemia, and values less than 8 mm/m2 indicate hypovolemia. Chang et al reported the only randomized controlled trial to examine quality of life and clinical outcomes of hemodialysis patients in whom IVCD was measured compared to patients in whom dry weight estimation was based solely on physical examination. They found lesser clinical mishaps and improved quality of life in the intervention group, an effect which was more pronounced in patients found to be hypovolemic. As this is the only reported randomized intervention, conducted with Asian participants, we sought to conduct a similar study in an independent hemodialysis population.

Objective Examination of the quality of life consequences of dry weight estimation in ESRD patients receiving dialysis with sonographic IVCD measurement.

Hypothesis We assume that adjustment of dry weight in ESRD patients receiving hemodialysis using sonographic IVCD measurements will improve quality of life.

Methods Study design: single-blinded cross-over clinical trial Study population: ESRD patients receiving chronic dialysis at the Hadassah Medical Center hemodialysis units. Exclusion criteria: pregnant women; patients treated with hemodialysis less than 3 months; significant tricuspid regurgitation; severe heart failure; patients with inadequate sonographic window for IVCD visualization.

Quantitative outcomes: Primary - rate of symptomatic hypotensive events during hemodialysis sessions; secondary - (1) quality of life, as evaluated using Short Form (SF)-36 questionnaire; (2) intradialysis clinical events: hypotensive episodes, gastrointestinal complaints, muscle spasm, tinnitus, headache and chest pain; (3) rate of emergent (unplanned) hemodialysis treatments; (4) average 24 h ambulatory blood pressure and sleep-related dipping.