Published: August 2010
Among patients with end-stage renal disease (ESRD) who require dialysis support, the age at onset, survival rates, and complexity of comorbidities are increasing. Patients with ESRD usually start dialysis with problems that require general medical care in addition to their dialytic care. Patients may choose to continue to see their primary care physician or may request that their nephrologist also assume that aspect of their care. Sometimes the choice is made for the patient by a physician familiar with the management of the patient’s problems or contractual insurance demands.
A survey of nephrologists found that nearly two thirds of respondents stated they provided most of the primary care to at least some of their dialysis patients. Additional medical care was most commonly delivered in the dialysis units. However, few nephrologists had written policies for primary care, and 75% did not follow clinical practice guidelines, were not familiar with guidelines, or had not read them but were aware of their existence. Thus, primary care physicians can still play an important role in the general medical care of patients with ESRD.
How can the care of ESRD patients be approached to ensure that a renal-related problem best managed by the nephrologist remains the province of the attending nephrologist while the primary care specialist provides the general medical care? Boxes 1 and 2 provide a framework for this division of patient care. Individual circumstances that take into consideration the skills and knowledge sets of the attending physicians are also of paramount importance.
|Box 1 Medical Problems Usually Managed in the Dialysis Unit|
|Control of hypervolemia and hypertension|
|Treatment of anemia with EPO|
|Replenishment and maintenance of iron stores|
|Control of renal bone disease (osteodystrophy), including dietary counseling, medications and treatment of vitamin D deficiency|
|Vaccinations, including hepatitis B, influenza, pneumococcal , tetanus|
|Vascular access for dialysis|
|Social work support|
|Box 2 Common Medical Problems in ESRD Patients that May Be Managed by Primary Care or Subspecialist Physicians|
|Control of serum glucose and hemoglobin A1c|
|Foot screening and care|
|Eye screening and care|
|Calcific uremic arteriolopathy (calciphylaxis)|
|Poor oral hygiene|
|Loss of tooth integrity with bone disease|
|Oral biofilm control|
|Hepatitis B and C infections|
|Carpal tunnel syndrome|
|Hip and spine fractures|
|Risk for falls|
|Obstructive sleep apnea|
|Restless leg syndrome|
|Poor sleep hygiene|
|General Health Care Screening|
|Age- and sex-appropriate cancer screening|
|Cardiovascular screening and treatment of cardiovascular disease|
|Vision and hearing evaluation|
|Safety evaluation at home|
|Risk for falling|
|Monitoring of Medication Use|
|Advanced Care Planning|
|Power of attorney for medical affairs|
|End of life care|
|Withdrawal of treatment|
What medical problems and practices can be altered to improve the outcome of ESRD patients? In addition to the processes related to the dialysis procedure itself, management of comorbid conditions and attention to preventive care can have a significant impact on patient morbidity and mortality and, in many instances, are better provided by a primary care physicians. However, approaches to the general medical care of an ESRD patient more often reflect the age- and gender-appropriate medical care that a patient should receive while taking into consideration the increased comorbidities and mortality associated with ESRD rather than medical care appropriate for a patient who was not on dialysis.
The two major causes of ESRD in the United States are diabetes mellitus and hypertension. As with most patients with end organ failure, ESRD patients often have a slowly declining course marked by periods of life-threatening events or complications. Any approach to general care must address both realities. Most patients starting dialysis have already experienced comorbid events relating to these two entities. There is also a high prevalence of prior cardiovascular disease, which approaches 80% in prospective studies. The care of these patients can reflect a primary or secondary strategy to prevent new or additional morbidity and mortality. As a manifestation of patient comorbidities, many patients die in the first year of dialysis, and 46% of those deaths occur in the first 4 months, primarily from cardiovascular disease, infection, liver disease, and withdrawal of treatment. One-year survival on dialysis is associated with several risk factors including lack of pre-ESRD care, positive HIV status, diabetic status, and low serum calcium levels.
Altered serum concentrations of commonly measured enzymes due to impaired renal excretion or decreased synthesis can affect the interpretation of some common laboratory tests. Historically, values for aminotransferases tend to be lower with ESRD. The exact cause is not known but might relate to lower pyridoxine levels due to impaired synthetic pathways. Although most reports are from the 1970s, a marginally elevated value still may be clinically significant.
Alkaline phosphatase can be of hepatobiliary, placental, or bone origin. Most elevations with ESRD are a manifestation of renal osteodystrophy, specifically high bone turnover disorder (osteitis fibrosa and cystica). Verification of source using a serum gammaglutamyl transpeptidase or alkaline phosphatase iosenzyme assay can settle the issue.
Lipase and amylase tend to be elevated due to impaired renal excretion of these fairly large enzymes. Increases of three to five times normal are seen in true pancreatitis, and lesser degrees might reflect the patient’s ESRD status rather than the etiology of abdominal pain.
Both serum troponin and creatine kinase (CK) levels are affected in ESRD. Troponins, especially troponin T (cTnT), are commonly elevated in asymptomatic patients, and many studies have associated elevated cTnT with survival in these patients. Troponins are also useful for acute coronary syndromes, although false-positive elevations in cTnT can occur. Total CK can be elevated in asymptomatic ESRD patients, but the use of the MB fraction provides good evidence of acute cardiac injury.
There are no data suggesting that ESRD patients need additional dialytic support after receiving iodinated contrast. Given the low osmotic load of current contrast agents, the risk of causing pulmonary edema is negligible. However, gadolinium used with magnetic resonance imaging (MRI) or magnetic resonance angiography (MRA) procedures should be avoided because it is highly toxic and can lead to nephrogenic fibrosing dermopathy.
As outlined in Box 2 the recommendations for lifestyle changes are the same as in the general population, especially initiatives for smoking cessation. Dietary restrictions unique to ESRD patients can make it more difficult for patients to achieve dietary changes, but the effort should still be made.
Estimated days of life saved by cancer screening is a function of life expectancy and lifetime risk of developing a cancer that will cause significant morbidity or death. This depends on the prevalence of the disease in the ESRD population, the sensitivity and specificity of the screening test used, the efficacy (and potential toxicity) of any interventions should the disease be present, and the overall survival with or without the disease. A financial evaluation of cancer screening in ESRD patients found the least efficient and cost-effective screening in female or white patients 50 to 70 years of age.
Cancer remains an uncommon cause of death in the ESRD population. This is in part due to the high risk for cardiovascular disease and infections. A report of international cancer registries found that certain malignancies are more common in patients with ESRD than in the general population. Cancer of the kidney, liver, bladder, cervix, thyroid, or tongue; Hodgkin’s lymphoma; and multiple myeloma were more prevalent, with the highest relative risk at a younger age and decreasing risk with aging. The incidence of lung, breast, colon, rectal, and prostate cancers are not increased. This pattern is the same as that seen after renal transplantation.
Uncertainty remains about the cost-to-benefit ratio of screening ESRD patients for malignancy given their higher mortality rates. Some argue that the benefits of screening disappear in patients who are diabetic, European American, or older than 65 years. However, each patient must be approached on an individual basis with consideration given to age, sex, comorbidities, transplant waiting-list status, ethnicity, and family and personal history. For example, targeted screening of mammography to women who have an expected survival of at least 5 years would greatly decrease the cost of screening but not affect the survival of patients who died.
Routine vaccination for hepatitis B, influenza, diphtheria, tetanus, and pneumococcal infection are recommended for all patients with ESRD. Vaccination done earlier in the course of chronic kidney disease seems to be more effective and is encouraged. The Centers for Disease Control and Prevention (CDC) provide regular updates on vaccination practices and recommendations with ESRD; these are available at their website (http://www.cdc.gov/vaccines/). The schedule for hepatitis B vaccination is different, and the use of or exposure to live influenza vaccine must be avoided. A large percentage of patients have evidence of exposure to hepatitis C, but screening is not routine.
Because cardiac disease remains the cause of death in more than 40% of patients, its evaluation and treatment remain vitally important in ESRD. However, few randomized, prospective studies are available to guide patient care. Screening with stress testing and echocardiograms is recommended. Among patients undergoing evaluation for renal transplantation, the test most often performed is a treadmill or dobutamine stress echocardiogram. We usually order this test for our other ESRD patients as well.
Numerous risk factors have been promulgated to be etiologic in ESRD patients, but at a minimum, traditional risk factors should be assessed and treated. Medication use as necessary for hypertension or dyslipidemia follows standard practice, although no data from randomized, controlled trials are available regarding the use of statins.
If intervention is necessary, coronary artery bypass grafting has been considered the treatment of choice. Newer data on the use of stents, which had been found inferior in the past, is in the state of re-evaluation.
The National Kidney Foundation has several evidence-based clinical practice guidelines available to assist in the care of patients with ESRD. These include the Kidney Disease Quality Improvement Initiative (KDOQI) and Kidney Disease Improving Global Outcomes (KDIGO). The American Heart Association also has a variety of policy statements and guidelines.