Study Comparing Dryweight Determination in Hemodialysis Patients With Two Methods
Study Comparing Dryweight Determination in Hemodialysis Patients With Two Methods
Adequate control of extracellular volume is a major goal of renal replacement therapy in
 patients with chronic renal disease. Fluid overload is present in the early stages of chronic
 kidney disease and contributes significantly to hypertension, arteriosclerosis and high
 prevalence of left ventricular hypertrophy. These are associated with high rates of morbidity
 and mortality in this group of patients, rates on dialysis in Brazil is around17.9 % per
 year. Dry weight during hemodialysis remains a delicate gap between hypervolemia and
 hypovolemic. Many studies have shown that tight control of post - dialysis weight is related
 to better outcomes in short term and higher long-term survival. Many methods have been
 proposed for estimating the hydration status of hemodialysis patients in an objective manner,
 including ultrasonography of the inferior vena cava and echocardiography. However, these
 methods are very time-consuming and cumbersome to use in daily practice. In most dialysis
 centers, the dry weight is evaluated on subjective clinical criteria, with trial and error
 and time consuming. It was recently introduced in Brazil to monitor body composition by
 multifrequency bioimpedance, called Body Composition Monitor ( BCM ) manufactured by
 Fresenius Medical Care. The BCM is a piece of bioimpedance spectrometry using a three
 compartment model, able to quantify objectively and accurately the extracellular volume and
 hydration status of each patient by measuring body resistance to an electric current. The
 procedure is safe, simple and relatively inexpensive. The BCM uses multi-frequency currents
 (ranging from 5 to 1000 KHz ). The availability of this device evaluation of body composition
 which assesses the dry weight more efficiently and objectively determine a target to be
 achieved to prevent left ventricular hypertrophy, hypertension better manage and improve
 cardiovascular outcomes, motivates us to perform this study. So the goal is to compare the
 efficacy between bioelectrical impedance analysis and clinical evaluation for suitability of
 dry weight in hemodialysis patients. A prospective, randomized, crossover study, which will
 include all chronic renal failure patients on hemodialysis at St. Luke 's Hospital (PUC -
 RS), including patients with at least three months on HD and over 18 years of age. The
 expected primary outcome is to achieve greater accuracy in determining the state of hydration
 and dry weight of these patients.
All patients in the study will undergo a period of prior randomization of a week, where data
 will be registered such as pre and post blood pressure, average weight gain (delta weight)
 between sessions and transdialysis complications.

 In the first phase, BIA and clinical evaluation to assess blood volume pre-hemodialysis
 session state in a single assessment will evaluate all patients in the study. The clinical
 assessment method of dry weight determination includes: patient history in search of signs
 and symptoms of volume overload, analysis of pre treatment blood pressure, adventitious
 sounds in pulmonary auscultation among others.

 Patients will be randomized in a systematic manner into two groups:

 Group A - Clinic Assessment (AC): patients will have dry weight determine by clinical
 examination, as unit routine, for four weeks. Clinical criteria for dry weight adjustments
 are: edema, dyspnea, reported shortness of breath, post dialysis blood pressure greater than
 or equal 140/90 mmHg.

 Group B - bioimpedance (BIA): BIA was used to estimate dry weight for four weeks, pre first
 HD session of the week.

 At the end of the first four weeks both groups will be assessed for hydration state, data
 registered in specific instrument to assess weight gain between sessions, frequency of
 complications and time to reach dry weight.

 After two weeks' interval, wash out, groups would change the method used to assess their dry
 weight. ( A - BIA and B -CA) After the second phase, all patients had a further evaluation
 with BIA to assess for hydration state, weight gain between sessions, frequency of
 complications and time to reach dry weight, all data registered in a specific instrument. Dry
 weight was achieved by adjustments made in all HD sessions, based on clinical evaluation or
 BIA. The maximum decrement to achieved dry weight was 500 grams of weight per dialysis
 session. Nurses did clinical evaluation in both groups.

 The unit heath team, nurses and doctors, trained in the methodology used in the research
 helped determine dry weight.
Inclusion Criteria:

 -  hemodialysis patient over 18 years old that accepted to participate

 Exclusion Criteria:

 -  Patients with metal orthopedic implants, cardiac pacemakers, patients with amputated
 limbs, due to the failure of evaluation of these patients by bioelectrical impedance
 analysis (BIA) and patients who do not accept participate in the study or decide to
 leave during the period of study research.