Three-times a week hemodialysis is the standard therapy for end-stage renal disease.
Most common maintenance dialysis with approximately 90% on this type of program.
Hemodialysis is arduous and patients experience fatigue the day after treatment.
Patients feel better on weekends off hemodialysis.
Hemodialysis free weekend days are associated with increase fluid and electrolyte retention and likely increase the risk of cardiac death.
Cardiac death is increased on the first day after the weekend rest.
Surgeries performed the day after hemodialysis or on the day of hemodialysis may be associated with better outcomes.
Utilizes a semi-permeable membrane as the artificial kidney.
Defined as the diffusion of molecules in solution across a semi-permeable membrane along an electrochemical concentration gradient ( Depner TA ).
Uses the process of diffusion to restore electrolyte and acid base balance.
Primary goal is to restore intracellular and extracellular fluid environment emulating normal kidney function.
When blood traverses the dialysis membrane pressure is applied that forces water and solutes across the membrane and out of the bloodstream thereby removing water.
Transports solutes from the dialysate into the blood, and solute concentration and molecular weight primarily determine diffusion rates.
Concentration gradient, cause solute diffusion from blood to dialysis and bicarbonate from dialysis to blood.
Urea and other small molecules diffuse quickly during dialysis.
Large molecules including albumin, phosphates, beta-2 microglobulin, protein bound solutes diffuse more slowly than smaller molecules during dialysis.
Hemodiafiltration is a form of hemodialysis that uses diffusive and convective clearance removing more middle molecular weight solutes, such as beta2 microglobulin, than standard hemodialysis. (Hemodiafiltration is not currently use in the US in an outpatient setting.
Solutes can also pass through pores in the dialysis membrane by a convective process driven by hydrostatic or osmotic pressure gradients known as ultrafiltration.
Removal of excess total body water is the purpose of ultrafiltration without changing solute concentrations.
Ultrafiltration, defined as fluid removal, can be performed currently or separately from hemodialysis.
Conventional intermittent treatment usually last 4-6 hours or less.
Goals of adequacy of dialysis based on the clearance of urea, a byproduct of protein catabolism.
Urea volume distribution reflects total body water such that kinetic modeling can predict morbidity and mortality.
The removal of the amount of urea is based on a formula involving the urea clearance of the dialyzer, the duration of dialysis and the patient’s volume of urea distribution.
This calculation is used daily to calculate the dialysis dose (Gotch FA et al).
Beta two microglobulin concentrations can be used to mark solute middle molecular weight solutes.
Longer treatment times associated with better outcomes.
Hemodialysis free weekends are associated with increased fluid and electrolyte retention that likely increase the risk of cardiac death.
Patient who gain more weight with dialysis are at increased risk for death, and longer treatment times may be required to maintain fluid balance.
Extended treatment hours improve blood pressure control and phosphate removal.
More frequent dialysis then the standard three sessions a week have shown reductions in blood pressure, need for antihypertensive medications, and enhanced regression of left ventricular hypertrophy.
More frequent treatments are associated with improved quality of life measures, but mixed results for anemia control and calcium phosphate metabolism (Suri RS et al).
A randomized controlled study comparing daily nocturnal hemodialysis with three times per week treatments indicated significant reduction in left ventricular mass in the daily group, as were improvements in blood pressure control, serum calcium-phosphorus metabolism and quality of life. (Culleton BF et al).
The proportion of elderly patients has increased, the number of patients with diabetes has increased and the number of patients with complex comorbidities has increased among hemodialysis patients (Rosasky SJ et al).
Higher levels of residual kidney function are present at the initiation of dialysis than was previously the case.
The safety of the procedure has increased with the improved dialysate delivery systems, improved monitoring devices, automated safety mechanisms, the use of standard physiologic bicarbonate-based dialysate, improved water quality standards, improved volumetric ultrafiltration controls, and improved sodium and potassium modeling (Oliver MJ et al).
Dialysis dependent chronic kidney failure has multiple systemic complications: anemia, mineral, metabolism, abnormalities, and hypertension.
Dialysis associated kidney failure is associated with anemia related to decreased erythropoietin production, disordered iron homeostasis, and coagulation dysfunction.
Dialysis dependent chronic kidney failure is associated with mineral metabolis disturbances, including decreased vitamin D Â production, hyperphosphatemia, and hypocalcemia, which contribute to secondary hyperparathyroidism and kidney osteodystrophy with alterations in bone morphology and increased rates of fracture and cardiovascular disease.
The rate of blood flow through vascular access, changes in hematocrit level, and changes in the electrical conductivity can be measured.
Automated controls of dialysis temperatures help maintain a constant body temperature.
A hemodialysis patient probably requires on the order of 3-12 mg of total iron absorption per day to stay in iron balance.
Approximately half of patients starting hemodialysis do not have permanent vascular access.
Oral iron inadequate to maintain iron balance, having an efficacy similar to no iron treatment.
Iron supplementation is required in almost all erythropoietin treated patients since iron deficiency may result in hypo-responsiveness to EPO.
In hemodialysis patients iron stores may be depleted from blood loss from numerous sources and total 1-4 g of iron per year.
Intravenous iron usage in hemodialysis dependent patients is standard care because the fraction of iron absorbed after oral administration is small and incorporation into circumventing red cell mass is slow.
Intravenous iron is a standard treatment for patients undergoing hemodialysis and among such patients, a high dose intravenous iron regimen administered proactively is superior to a low-dose regimen administered reactively and results in lower doses of erythropoiesis stimulating agent being administered (PIVOTAL trial).
In EPO treated patients, failure to maintain iron stores will correct iron deficiency is a common cause of treatment failure after oral iron supplementation and intravenous iron is recommended for patients unable to maintain adequate iron status with oral agents.
Partial correction of anemia with ESA’s is the cornerstone of management for patients undergoing dialysis, as these agents increase hemoglobin levels, and reduce blood transfusion rates.
Partial correction of anemia in patients undergoing dialysis enhances the quality of life.
Intensive treatment with ESA’s in dialysis patient, targeting near-normal hemoglobin levels in the Normal Hematocrit Study (NHS), and in the Correction of Hemoglobin and Outcomes in Renal Insufficiency (CHOIR) study, and the Trial to Reduce Cardiovascular Events with Aranesp Therapy (TREAT) further reduced the need for blood transfusions but with increased composite of death and nonfatal myocardial infarctions, stroke and cardiovascular events.
Acquired cystic disease occurs in 85-90% and 5-30% of such patients may develop renal cancer.
Sudden cardiac death more common during Mondays and Tuesdays in association with longer interval between dialysis and the wider fluctuations in electrolyte concentrations.
The presence of anemia in hemodialysis patients associated with left ventricular hypertrophy, left ventricle dilatation, higher cardiac mortality and morbidity.
In patients on maintenance hemodialysis larger body size or muscle mass represented by a higher BMI or a higher serum creatinine concentration, is associated with greater survival (Kalantar-Zadeh K et al).
Pulmonary congestion is highly prevalent and often asymptomatic among patients with ESRD.
Extravascular lung water measured by ultrasound B-lines score (BL-US) in a multicenter study that enrolled 392 hemodialysis patients detected moderate-to-severe lung congestion in 45% and very severe congestion in 14% of the patients (Zocalli C).
In the above study patients with moderate-to-severe lung congestion, 71% were asymptomatic or presented slight symptoms of heart failure, and those with very severe congestion had a 4.2-fold risk of death, and a 3.2-fold risk of cardiac events.
In on maintenance hemodialysis a gain in dry weight along with a parallel increase in muscle mass is associated with the greatest survival (Kalantar-Zadeh K et al).
In patients on maintenance hemodialysis a discordant combination of muscle gain and weight loss confers a higher survival benefit than dies weight gain accompanied by loss of muscle mass (Kalantar-Zadeh K et al).
Mean parathyroid hormone level 7 times that of a patient not on dialysis.
Vascular access options include arteriovenous fistula, synthetic arteriovenous graft, and central venous catheter, utilized in 53%, 21%, and 24% of patients, respectively in the US (US Renal Data Sysyem).
When hemodialysis is needed rapidly a temporary catheter can be placed directly into a large central vein in the neck, upper chest or groin.
A temporary catheter can be tunneled under the skin in the chest to improve security is the temporary catheter is utilized for a prolonged period of time.
Catheters carry increased risk for infection than more permanent and durable vascular access.
Hemodialysis catheters associated with a frequency of thrombosis of 0.5-3.0 events per 1000 catheter days, with shortened dialysis treatments, less than adequate dialysis and increaed morbidity and mortality (Saran R et al).
Hemodialysis catheters fail at a rate of 50% with an one year and up to two thirds of the failures are due to thrombosis.
Hemodialysis catheters commonly associated with sepsis and death in patients undergoing hemodialysis.
Hemodialysis catheter thrombosis occurrs at a frequency of 0.5-3.0 events per 1000 catheter day, and is associated with shortened dialysis treatments, less than adequate dialysis, increased morbidity and mortality (Saran R et al).
Arteriovenous dialysis grafts have a thrombosis in more than 50% of cases within one year after placement, necessitating a salvage procedure in more than 75%of cases.
Arteriovenous graft thrombosis usually occurs at the venous anastomosis in proximity to a stenotic lesion that has resulted from aggressive neo-intimal hyperplasia.
Heparin has been the traditional solution instilled into central venous catheter lumens for hemodialysisto prevent hemodialysis.
In a randomized study of 225 patients in whom a newly inserted central venous hemodialysis catheter was inserted to a catheter locking regimen of heparin (5000 u per ml), three times per week or recombinant tissue plasminogen activator (1mg) weekly: rt-PA as a locking solution reduced the incidence of catheter malfunction and bacteremia (Hemmelgarn BR et al).
In the above study the frequency of bleeding or other adverse events was not increased with the use of rt-PA weekly as compared with unfractionated heparin three times per week.
Permanent vascular access can be placed by an arteriovenous fistula, the connecting of an artery to a vein, that takes weeks to months to mature and become large enough to carry the large amount of blood flow needed for hemodialysis.
In patients that do not have adequate veins an arteriovenous graft can be placed with the use of synthetic material.
Individuals on maintenance hemodialysis has a annual mortality of approximately 20% in the United States, mostly related to cardiovascular or infectious processes.
Survival of patients on maintenance hemodialysis has not improved substantially, and there has been no survival benefit from increasing the dialysis dose, lowering serum cholesterol levels, correcting hyperhomocysteinemia or improving anemia (Kovesdy CP et al).
Death rate 20% per year during the first 2 years after maitenance dialysis is begun.
Hospitalization rates for hemodialysis averages almost 13 hospital days and 2 admissions per year.
Uremic pruritus is distressing and und2242ecognized condition that affects more than 60% of patients undergoing hemodialysis, with 20-40% of patients reporting moderate-severe pruritus.
Uremic pruritus Is associated with poor sleep quality, depression, impaired quality-of-life, increased risk of infection, and increased risk of death.
Dialysis Otcomes and Practice Patterns Study (DOPPS) reported crude1-year mortality rates from 1996-2002 were 6.6% in Japan, 15.6% in Europe, and 21%.7% in the US (Goodkin DA et al).
Variations in death rates due to shorter treatment times, less frequent use of fistulas and staffing hemodialysis centers with technicians rather than nurses (Folet RN, Hakim RM).
In a randomized study to undergo HD 6 times per week or three times per week for 12 months: more frequent HD was associated with more favorable outcomes of death, or change in left ventricular mass and death or change in physical health composite, but was associated with more frequent vascular access interventions (FHN Trial Group).
There is evidence that surgeries perform the day after hemodialysis or on the day of hemodialysis may be associated with better outcomes causing less disruption in patient care is likely to be beneficial to patients overall (Fielding-Sing V).
Among patients with end-stage kidney disease, a longer interval between hemodialysis and surgery is significantly associated with higher risk of postoperative mortality, mainly among those who did not receive hemodialysis on the day of surgery:The magnitude of the absolute risk differences is small.
Tunneled catheters associated with increased rate of hospitalization, risk of death, and cost of care compared to more permanent vascular access, due primarily risk of such catheter related bacteremia (Lacson E Jr et al).
Variation in mortality among countries may be due to risk of death related to cardiovascular risk in respective populations (Yoshino M et al).