The indications for initiation of dialysis often develop long after the patient has progressed within CKD 5, commonly with an eGFR of 10 mL/min/1.73 m2 or less. Medicare has acknowledged this by reimbursing dialysis only in eligible patients whose eGFR is below 10 mL/min/1.73 m2.16 There are also acute indications for initiation of dialysis, such as uremic pericarditis, hyperkalemia, bleeding related to uremic platelet dysfunction, and metabolic encephalopathy related to uremia (and reimbursement for dialysis can be justified), but these are uncommon.
RENAL REPLACEMENT THERAPY CHOICES
The choices of treatment for kidney failure (note: treatment, not cure) are medical management, hemodialysis, peritoneal dialysis, and transplant. Each choice has its advantages and disadvantages, and all patients should receive clear explanations of what they can expect from each modality.
While younger, higher-functioning individuals are likely to benefit from dialysis, patients with extensive comorbid illnesses and/or low functional status tend to respond poorly17; medical management may be the best choice for these patients. In one recent study, the functional status of residents in skilled nursing homes was examined, before and after initiation of dialysis. At one year, 58% of the nursing home residents who underwent dialysis had died, and only 13% had maintained their pre-dialysis functional status.18
Another research team recently compared conservative management of CKD 5 (ie, medical therapy without dialysis) with dialysis in elderly patients. For patients 75 and older with extensive comorbid illness, the researchers found no statistically significant survival benefit to dialysis.19
Dialysis, whether administered as hemodialysis or peritoneal dialysis, is a rigorous, intensive medical therapy. Dialysis does not necessarily prolong life in patients with extensive comorbidities, and it does not always enhance quality of life.18,20-23 The decision to undergo dialysis is personal and individual, and both the patient and family should be actively involved in making it. Primary care providers should be the nephrologist’s ally in the discussion of therapy for renal failure; often, they have cared for the patient for years, and they understand the patient and family dynamics.
An important message the nephrology practitioner must communicate is that choosing medical management without dialysis is not withholding care; sometimes it is a more humane choice.24 Dying of kidney failure can be a peaceful and comfortable death: As the uremic toxins build up (with eGFR ≤ 2 mL/min/1.73 m2, although this can take many years), the patient becomes confused and slowly slips into a sleepiness that leads to death.25 Hospice is usually involved to support the patient and family.
Hemodialysis
Hemodialysis is the most common, best-known treatment modality for CKD in the US, with about 94% of patients choosing it.3 In this process, blood is removed from the body (approximately 500 cc at a time) and filtered through a semipermeable membrane that removes uremic toxins and excess fluid, normalizing the metabolic and electrolyte derangements. The filtered blood is then returned to the patient.
The average dialysis session is four hours long and is conducted three times per week, following recommendations from the 2002 Hemodialysis Study (HEMO).26 Most patients come to a free-standing dialysis center on a Monday/Wednesday/Friday or a Tuesday/Thursday/Saturday schedule.
In theory, there is no such thing as too much dialysis (since the kidneys work 24 hours per day, seven days per week); thus, researchers have recently examined lengthening dialysis in an attempt to extend survival.27-29 According to study results, patients who undergo longer dialysis times generally enjoy better nutrition with a more liberal diet, require fewer medications, have reduced incidence of increased left ventricular mass (a marker for coronary artery disease), and report better quality of life, all in addition to a survival benefit; however, the latter was not considered statistically significant in any of the studies.27-29 Additionally, this survival benefit may not extend to daily hemodialysis; in a recent publication, daily hemodialysis was associated with a 60% higher death rate.30
A number of dialysis units have begun to offer nocturnal dialysis. In this option, patients sleep at the unit for eight hours, three nights per week, for a total of 24 hours of dialysis (vs the typical 12 hours per week). Some patients receive dialysis at home, allowing them to dialyze for six weekly sessions of two to three hours. This strategy attempts to mimic a more “natural” state.
One of the primary challenges associated with hemodialysis is establishing and maintaining a vascular access. An arteriovenous (AV) fistula is the access of choice because its use reduces the likelihood of clotting, improves access survival, and increases clearances during dialysis.31 However, the AV fistula is most effective if it is placed a minimum of six months before use.32