Dialysis treatment takes toll on diabetic foot care

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A convergence of comorbidities means diabetic patients on dialysis have an even higher risk of foot ulcers and amputation than those without renal disease. The potential for preventing these complica­tions at dialysis centers is too often underappreciated by practitioners. 

By Larry Hand

Concurrently with the growing epidemics of obesity and diabetes around the world, diabetic foot complications occur more frequently now than ever before. Even with some preventive measures widely identified, researchers are finding that preventive care is not being delivered adequately or regularly to patients with diabetes. In no other patient population is this more obvious than in diabetic patients receiving regular dialysis.

“Dialysis is a miserable existence. It basically keeps you alive while you’re waiting for the best treatment, and the best treatment is a kidney transplant. The best treatment of all is prevention, but once you get to this stage, the best treatment is a kidney transplant. When you’re on dialysis, this takes over your life, and you may forget, because you’ve got no sensory symptoms, that you’ve got high-risk feet,” Andrew Boulton, MD, professor of medicine at the University of Manchester, UK, said during a presentation in March at the Diabetic Foot Global Conference (DFCon) in Los Angeles.

The intensity of dialysis treatment can overwhelm patients and cause them to forget about caring for their feet and make them less likely to use the right footwear, Boulton said.

“We believe there is a great need for foot care to be provided,” he said, noting that dialysis centers are ideal places to provide that care.

Dialysis often goes hand in hand with chronic kidney disease (CKD) and end-stage renal disease (ESRD), both of which are risk factors for developing diabetic foot complications.1 The combination of CKD, ESRD, and dialysis just adds to the risk. And in an August 2010 study published in Diabetes Care, Boulton and colleagues established dialysis alone as an independent risk factor for foot ulcers in patients with diabetes and more serious stages of CKD.2 However, according to a 2008 study in the same journal, even moderate CKD can be strongly associated with diabetic foot ulcers and lower extremity amputation (LEA).3

The diabetes-CKD-ESRD-dialysis chain appears to be a vicious circle. In 2003, researchers found that diabetes was the strongest risk factor for LEA in patients undergoing hemodialysis.4 A 2006 study found a strong association between the start of dialysis treatments and recording of a first foot ulcer in patients undergoing renal replacement therapy (RRT), which includes dialysis.5

In another study by Boulton and colleagues, published in 2010, individuals with CKD who were on dialysis and had a high-level amputation had significantly lower survival rates after amputation than individuals with no renal disease.6 When they compared people with no renal disease to patients on dialysis using a proportional hazard model, they found the dialysis patients had a 290% increase in hazard for death.

“People are living longer and they’re living longer with complications of diabetes,” said David G. Armstrong, DPM, MD, PhD, professor of surgery and codirector of the Southern Arizona Limb Salvage Alliance (SALSA) at the University of Arizona College of Medicine in Tucson. “The furthest end stage of complications of diabetes includes blindness, amputation, and dialysis. These are due to both micro- and macrovascular complications, but predominantly microvascular, particularly for blindness and dialysis. When they happen, they take a tremendous toll. Very often, all three of them happen at the same time.”

The big picture

Recent reports paint a grim picture for these epidemics. In the June issue of the American Journal of Preventive Medicine, researchers forecast that 51% of the US population will be obese by 2030.7According to the World Health Organization, half a billion people worldwide—12% of the world’s population—are obese, and North and South America have the highest percentages of obese individuals. Obesity is associated with development of diabetes and CKD.8

According to the US Centers for Disease Control and Prevention, almost 26 million Americans had diabetes as of January 2011 and an estimated 79 million US adults have prediabetes.9 Diabetes affects 8.3% of all people in the US and 11.3% of US adults, and prediabetes affects 35% of US adults. The CDC estimates that 7 million people in the US (27% of all those with diabetes) have diabetes but don’t know it.

By 2030, 10% of the world population will have diabetes, growing from 366 million people in 2011 to 552 million people, according to a November 2011 report by the International Diabetes Federation.10Diabetes cases are expected to increase by 90% in the poorest areas of the world.

The Organisation for Economic Co-operation and Development (OECD), which promotes policies to improve economic and social well-being and tracks numerous statistics, reports that the prevalence of ESRD patients undergoing dialysis increased from 36 patients per 100,000 population in 1985 to 118 patients per 100,000 in 2007.11 Japan had the highest increase, from 55 per 100,000 in 2003 to 186 per 100,000 in 2007. All other countries showed lower prevalence rates than the US.

Foot care practitioners can play a significant and proactive role in the continuum of care for these patients.

“Often, the foot doctor almost becomes the primary care doctor for a lot of diabetics,” said Bret Ribotsky, DPM, a podiatrist in private practice in Boca Raton, FL. “They see their diabetic doctor every couple of months, their internist periodically. They don’t like going to their internist because every time they go there, they get a disease. They say, ‘I didn’t have diabetes before I came to you and now I have diabetes.’ They say, ‘I don’t like going to that doctor; he keeps giving me diseases.’”

Lower extremity practitioners may seem less threatening to these patients, Ribotsky said.

“A lot of times the doctor they feel most comfortable with is the one whom they don’t really feel like can hurt them,” he said. “They don’t realize that I can cut their leg off if I have to, or do tendon transplants or some other big intervention. But the goal, of course, is to avoid that as best you can.”

He said he has patients who have been on dialysis for 11 or 12 years who go on cruises and participate in other activities, but that those patients are very strict about self-management.

Treatment through teamwork

Practitioners agree that the key to treating these patients is quick action by a team of providers, and many clinicians are now calling for the provision of foot care at the time and place of dialysis or timed in conjunction with the dialysis treatments. Practitioners also say to move these patients to the front of the line for treatment.

Boulton and colleagues, in a 2010 study in Diabetes Care, reported a high prevalence of lower extremity complications in a cohort of dialysis patients: foot ulcers, 12%; neuropathy, 79%; peripheral arterial disease, 57%; history of foot ulceration, 34%; and prior amputation, 18%.12 They found that nearly all (95%) of the dialysis-treated diabetic patients in their study were at high risk for foot problems and, as a result, suggested that all such patients be considered high risk. The authors also noted the demands of dialysis may keep patients from following up with practitioners for appropriate foot care and suggested scheduling foot evaluations during or immediately after dialysis as part of an effective prevention strategy.

A May 2012 study offered some hope for dialysis patients who have sleep loss and mood disorders as a result of painful peripheral neuropathy.13 The study results showed the epilepsy medications gabapentin and pregabalin significantly reduced pain intensity and improved quality of sleep and symptoms of depression in 31 out of 40 patients over a 12-week period.

Dialysis patients should receive a high priority for treatment, Ribotsky said.

“If they have a problem, you see them right away,” he said. “You don’t make them wait two or three days, because little things can become big things very quickly. You basically want to approach them as a VIP/royalty person, and use colorful words so they’ll remember what you say.”

Teamwork between practitioners is also essential, Armstrong said.

“All must be under the care not only of their primary care physician, but a diabetologist and a nephrologist,” he said. “It’s extremely important to have a real team. This is when the medical portion of the team is really working in high gear with the ‘toe and flow’ members of the diabetic foot team.” “Toe and Flow” is the name of SALSA’s integrated program for diabetes management in which “toe” is podiatry and “flow” is vascular surgery (see “Taking a team approach to diabetic limb salvage”).

There’s not a lot of good news about foot complications in dialysis patients, but there is some, Armstrong said.

“That good news is that whenever we see a patient like this, we are exceedingly aggressive in our initial assessments to try to go after the wound and salvage things. We definitely can be successful, but we’re successful less often in this population by far than we are in all of our other patients with diabetes,” he said.

The frequency with which lower extremity practitioners see patients from this challenging population will depend on how much of their time is spent in a university or hospital-based practice compared with a private office setting, according to Zacharia Facaros, DPM, a podiatrist at the Weil Foot & Ankle Institute in Des Plaines, IL.

“Practitioners associated in hospital-centered clinics will typically encounter an increased number [of dialysis patients] as a result of diabetes mellitus multidisciplinary management programs and dialysis clinics,” Facaros said. “Multispecialty affiliations and locations make care more accessible for patients. The number of patients presenting with diabetes and subsequent nephropathy will also vary among geographical regions throughout the country, varying as well between urban and rural areas in the same surrounding city limits.”

Inattention to prevention

Preventing diabetic foot complications is an important goal in dialysis patients as in other patients with diabetes—yet a study published in the July 2010 issue of Diabetes Care reported that preventive care is infrequently provided to high-risk patients.14 In that study, Boulton and colleagues evaluated the medical records of 150 high-risk patients with previous foot ulceration or amputation and 150 patients on dialysis to see whether the patients received preventive education and services.

In the combined study population, the incidence of ulceration was 210 per 1000 person-years. However, for the dialysis group, the incidence of amputation was significantly higher (58.7 per 1000 person-years) than for the other group (13.1 per 1000). In the study population overall, only 7% of patients received therapeutic shoes, 1.3% received professional education, and 30% received preventive care from a podiatrist.

The findings are particularly discouraging in light of previous studies that found specialized foot programs reduced incidence of amputations by 50%15-17 andfoot ulceration by about 50% (with therapeutic shoe use);18 in addition, fewer recurrent ulcers developed in patients receiving regular foot care.19

In a 1995 study, the provision of consistent multidisciplinary foot care at a foot clinic for patients who had undergone renal transplant reduced the incidence of gangrene and amputations compared with previous years; regular foot care also reduced healing times compared with times for diabetic patients without renal transplants.15 Treatment included administration of antibiotics, podiatric care, and recommendations for proper footwear.

“Prevention services for the diabetic foot are simple to establish and can be made easily accessible through organized multidis­ciplinary care,” Boulton and colleagues wrote. “These data provide further evidence that preventative foot care is not regularly provided, even among patients with the highest risk for lower limb complications. It also highlights an opportunity to improve prevention services for the diabetic foot with simple protocols for evaluation and referral.”

The same researchers used stronger language in a 2010 article published in Current Diabetes Reports.1

“The burden of diabetic foot disease in patients on dialysis as exemplified by high morbidity, mortality, and costs makes any emphasis on the need for prevention and appropriate management obvious. The case for prevention is so compelling that it is hard to understand why foot care is not yet an integral part of most dialysis units worldwide,” they wrote.

Facaros said that patients in this population are often not compliant, possibly due to lack of family or socioeconomic support. He recommends progressive gait balance training and additional physical therapy for ambulatory dialysis patients.

The high rates of peripheral neuropathy associated with dialysis present another clinical concern, he said.

“Neuropathic patients, whether restricted to assisted-walking devices or wheelchairs, require closer monitoring in order to prevent pressure-induced skin compromise and chronic irritation. This would entail frequent visits to the lower extremity practitioner but we also call upon the patient to immediately notify home health, nursing, and physician team members of any abnormal symptoms,” he said.

“My experiences have taught me to handle these patients with meticulousness and intense consideration, tailoring to the individual’s needs and functionality,” Facaros said. “The presence of infection and ischemia must be addressed in as complete a manner as possible. When treating this population, the physician must expect a prolonged healing timeline, and complications are inevitable and will occur.”

Sometimes, amputation is not a last-resort move, Armstrong said. For instance, it is very challenging to treat wounds in a dialysis patient who has a deep heel ulcer and to revascularize the wounded area.

“The outcomes from those grades and stages of wounds are far and away the worst of any patients that we treat. At times, we consider amputation rapidly. This is particularly true if we feel we can get the patient walking more rapidly and efficiently. We think about that [amputation] earlier now if the patient is a good rehabilitation candidate,” he said.

If a patient is not a good rehabilitation candidate and will be confined to bed regardless of treatment, he added, then the goal is just to temporize the wound and keep it uninfected, which amounts to what Armstrong calls “lower extremity hospice” care.

Still, team care is the answer.

As Armstrong put it in layman’s terms, “If a patient is tremendously out of whack, then the goal is to try to get them to a member of the team that can get them into whack.”

Larry Hand is a writer in Massachusetts -.lermagazine.com