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Donna Myers, M.D.
10-11-2010
Trinidad and Tobago Information Author: Alan Patrick, MB, FRCP
- Approximately 7 locations offer dialysis in T&T (50 machines), mostly hospitals
- ~380 patients in T&T are on dialysis
- Usually hemodialysis is performed, however, peritoneal dialysis is available through San Fernando Hospital.
- About one-third of patients are covered by the government, while the other two-thirds pay for dialysis care.
- As many as 60% of patients on dialysis have diabetes.
- As many as 10% of patients with diabetes are on dialysis but this number is misleading since the number with end-stage renal disease is much higher.
- Availability of dialysis machines is limited and not everyone who needs dialysis is able to obtain it; as a result, many patients die early of heart disease instead of kidney failure.
- Management options for all people with end-stage renal disease (ESRD) include maintenance hemodialysis (HD), peritoneal dialysis (PD), and renal transplantation (Tpl).
- About 40-50% of all people on dialysis have ESRD secondary to diabetic nephropathy (DN), making diabetes the most common cause of ESRD.
- Survival on dialysis is worse for patients with diabetes compared to those without diabetes.
- Survival on PD and HD are similar in most studies. Five year survival for patients with diabetic nephropathy on PD is about 24%, on HD is about 27%, vs. 33% for all patients.
- 50% of asymptomatic diabetic patients with diabetes and advanced CKD, have previously unsuspected coronary artery disease.
- Most deaths of patients on renal replacement therapy are from accelerated cardiovascular disease and infections.
- "Uremia" refers to a constellation of multi-organ signs and symptoms due to accumulation of nitrogenous waste products.
- Signs and symptoms that constitute "Hard" indications for starting dialysis include uremic gastrointestinal bleeding, refractory fluid overload with recurrent congestive heart failure, uremic serositis (pericarditis, pleuritis or peritonitis), uncontrollable metabolic acidosis and/or hyperkalemia, and altered mental status with no other apparent etiology.
- Less clear, "Soft", indications for initiating dialysis include anorexia, nausea, metallic taste, weight loss, fluid retention, inattention, and failure to thrive in a patient with stage 5 CKD (GFR < 15 ml/min/1.73 m2).
- Early referral to nephrology in stages 1 - 3 chronic kidney disease (CKD) may allow reversal or slowing of DN progression. With continuing irreversible decline in GFR, patient education should begin by stage 3 CKD.
- Because of co-morbidities and uremic symptoms in diabetes, start dialysis with GFR 10 - 15 < 10 ml/min/1.73 m2, rather than < 10 ml/min/1.73 m2 as in other patients.
- Selection of modality of treatment (HD, PD, Tpl) is guided by co-morbidities and preferences of the patient and family.
- PD is an option for most diabetic patients. Limiting factors: poor vision, inadequate manual dexterity in the absence of home support, uncontrolled diabetes (type 1), multiple abdominal surgeries, and morbid obesity.
- HD is also an option. Limiting factors: difficulty creating a permanent vascular access, hemodynamic instability during dialysis, and mobility problems.
- If patient is a candidate for kidney Tpl, this is preferred, particularly if there is an eligible living related or unrelated donor (see Kidney Transplantation). Five year all patient survival with a kidney transplant is 69% better than for dialysis.
- Late referral to nephrology (within 6 months of starting dialysis) occurs in 25-50% of patients and is associated with a poorer outcome.
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Patient Preparation: Pre-ESRD, inform the patient of his/her treatment options. Optimally, use a dialysis nurse, a transplant representative, renal dietician and social worker.
- Prior to selecting HD or PD, refer to vascular surgeon, to estimate the feasibility of a native arteriovenous fistula (avf), a fistula/graft (avf/g), or a Tenchkoff peritoneal dialysis catheter.
- For HD, a native fistula (using patient's own vein and artery) is far preferable to a graft, which itself is preferable to a catheter. Lead time for maturation of avf is at least 3-6 months; for an avf/g 4-6 weeks. A catheter may be used immediately.
- With extensive peripheral vascular disease, increased risk for a steal syndrome (distal ischemia due to high blood flow through an avf or avf/g); PD may be a better option.
- Temporary or long-term tunneled HD catheters may cause central venous stenosis, thrombosis and life-threatening infections; they should be avoided whenever possible.
- With morbid obesity or multiple abdominal procedures, PD may not be feasible; HD may be the only dialysis option. Lead time for a PD catheter is 3-4 weeks.
- Infection may complicate both HD and PD.
- Catheter-related PD complication: Bacterial peritonitis occurs about once in 30 treatment months. Signs and symptoms: abdominal pain, cloudy effluent; generally without bacteremia. Treat usually with intra-peritoneal antibiotics in an out-patient setting.
- HD complication: Access-related infections may begin as undetected intermittent bacteremia, progressing to symptoms of overt sepsis (rigors, fever, nausea and vomiting) with no other obvious source. Bacterial endocarditis (Staphylococcal aureus) with or without septic emboli is common. Infection rate is 10-20 times more common with a catheter vs. an avf.
- Consider pre-emptive Tpl for diabetic patients with stages 4-5 CKD, if there is a suitable donor. Evaluation begins within 6 months of needing dialysis. Tpl after starting dialysis is possible if patients who are a good surgical risk.
- Hypertension in ESRD is generally volume-related. Other complications of fluid overload: CHF and hemodynamic instability during dialysis.
- Lower fluid gains between-dialyses are achieved by dietary counseling (sodium restriction) and glycemic control to avoid excessive thirst and fluid overload.
- Intra-dialytic hypotension occurs in up to 30% of hemodialysis HD treatments, and . It is more commonly in the among patients who are elderly, those with have autonomic dysfunction (diabetes), high fluid gains or poor cardiac reserve. Complications during dialysis include painful muscle cramps, an increased risk of stroke and myocardial ischemia; chronic fluid overload and worsening of cardiac function creates a vicious cycle.
- Therapies for recurrent intra-dialytic hypotension including dietary counseling, cooling the dialysate, sodium modeling (varying the sodium concentration of the dialysate) and pharmacotherapy with pre-dialysis midodrine have limited success. Patients with this problem may benefit from a transfer to PD.
- Many new dialysis patients are non-oliguric (urine output > 500 ml/day). Preservation of residual GFR is important for survival on PD and may be beneficial in HD; Thus, avoid non-emergency i.v. contrast and NSAIDs during PD and HD as long as the patient still makes urine.
- Ultrafiltration (UF) with conventional HD occurs 3x/week for 3-4 hrs a session. Ideal hourly fluid removal (UFR) is < 500 ml to avoid hemodynamic instability . but fluid gains between dialyses often exceed this goal, requiring UFR > 1L/hr. Daily home HD (not readily available) and daily PD have a lower, better tolerated UFR.
- On PD, hyperglycemia limits the osmotic gradient to remove fluid, and fluid may actually be reabsorbed. Chronic hyperkalemia is a problem oliguric HD patients; dietary potassium restriction is needed.
- Hypokalemia often occurs in PD patients; dietary potassium liberalization or supplements may be needed (confusing for previously potassium-limited patients). "
- Monitor calcium, phosphate and parathyroid hormone in all ESRD patients. K/DOQI guidelines: serum calcium 8.4 - 9.5 mg/dL, phosphate 3.5 - 5.5 mg/dL, calcium-phosphate product < 55,;intact PTH 150 - 300 pg/ml.
- For hyperphosphatemia, non-aluminum containing phosphate binders (calcium acetate, sevelamer and lanthanum carbonate) are taken with meals. With serum phosphate < 5.5 mg/dL, but iPTH still above target, vitamin D analogs are added (calcitriol, paricalcitol and doxercalciferol). Use calcimimetics (cinacalcet) if iPTH remains > 300 pg/ml and calcium is > 8.4 mg/dL; these agents are very effective but not well tolerated due to g.i. side effects.
- CVD accounts for 40 - 50% of deaths on HD and PD.
- Coronary artery calcification is seen in even young dialysis patients. Medial calcification is seen more commonly than intimal calcifications CKD patients.
- The cause of accelerated atherosclerosis of dialysis patients is unclear; anemia, left ventricular hypertrophy, hypertension, chronic volume overload and mineral imbalance are all postulated.
- Predisposing to vascular calcification in ESRD is hyperphosphatemia, hyperparathyroidism, vitamin D therapy and vitamin D deficiency, and chronic inflammation.
- Lower extremity peripheral vascular disease present in up to 25% of HD patients. Risk factors: cigarette smoking, diabetes, age, male gender and hypertension.
- Some dialysis clinics schedule monthly "foot checks" n their diabetic patients, to reduce the risk of infections and limb loss.
- Unless the dialysis patient is being considered for transplantation and has a BMI > 40, weight loss is not stressed although recommended. Regular exercise is beneficial.
- Protein-calorie malnutrition correlates with mortality in ESRD. Linear relationship between serum albumin level and survival on dialysis, persisting even with normal serum albumin. Stop the pre-dialysis "renal diet", limiting protein, once dialysis is started.
- PD patients are prone to hypoalbuminemia due to protein wasting in dialysis effluent. Should receive 1.2 g/kg/day dietary protein. Persistent hypogluminemia, especially post-operatively or during chemotherapy, may require temporary or permanent transfer to HD.
- ESRD patients receive erythropoiesis stimulating agents (ESA's) with HD or PD. Poor response is seen with inflammation, chronic transplant rejection, HIV, occult infection, and severe hyperparathyroidism.
- Most dialysis patients require supplemental iron; IV iron on HD or with monthly blood draws for PDAll dialysis patients require folic acid, B and C vitamins.
- Guidelines for anemia management in CKD include target Hgb between 11 - 12 g/dL.
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Glycemic Management: Blood glucose can be checked on dialysis without finger sticks, allowing for timely insulin adjustment.
- Hypoglycemia during HD is unusual as the dialysis bath contains 200 mg/dL glucose.
- Large between-dialysis fluid gains requiring high hourly ultrafiltration rate (HD) or higher osmotic strengths of dialysate (PD) correlate with increased morbidity and mortality. Counsel patients to restrict dietary sodium intake and avoid uncontrolled hyperglycemia.
- HbA1C is used to monitoring long-term glucose levels even on dialysis. Falsely elevated HbA1c readings may result from non-immunoassay methods due to elevated BUN acidosis and iron deficiency.
- Target HbA1C level 6-7% for type 1 diabetes and 7-8 in type 2 diabetes. If the low A1C level is not due to malnutrition, it is a good prognostic indicator.
- With ESRD, avoid metformin (risk of lactic acidosis) and rosiglitazone (cardiovascular mortality). Sulfonylureas such as glipizide may be used with caution; avoid glyburide and chlorpropamide (long-acting). Alpha-glucosidase inhibitors are not recommended in CKD. (see Diabetes and Renal disease)
- Although intra-peritoneal insulin has been suggested for PD patients, it is difficult to dose in patients on PD, and adds a source of potential contamination. Consider non-glucose containing dialysate solutions (icodextrin) for diabetic PD patients with diabetes, although it is not readily available.
- PD will not properly ultrafiltrate if the blood glucose is high; in chronically poor glycemic control, HD may be a better option.
- Manage severe hyperglycemia and ketoacidosis in oliguric or anuric patients by low dose IV insulin. Fluid replacement is not warranted and potentially hazardous.
- Hyperkalemia is a potentially life-threatening complication of hyperglycemia in ESRD patients. Reverse extra cellular shifts of potassium with insulin administration. Avoid routine administration of concentrated glucose to an unconscious diabetic patient without first confirming hypoglycemia. When altered consciousness is from hyperglycemia in CKD (even pre-ESRD), administering concentrated glucose solutions without insulin may worsen hyperkalemia, cause cardiac arrhythmias.
- Carefully define who is the primary care physician; a multi-disciplinary approach to problems beyond ESRD is indicated.
- Monitor the dialysis patient quarterly with HbA1C levels, reported to the patient and primary care giver.
- Early studies suggesting more rapid progression of diabetic retinopathy on hemodialysis have not been substantiated. Routine ophthalmology visits are nevertheless imperative.
- Consider cardiology consultation given the high rate of CVD in CKD.
- Routine visits to podiatry and early referral to vascular surgery if indicated. Monthly "foot checks" in the dialysis unit have been shown to save limbs.
- Kidney Tpl yields improved survival of all patients with ESRD when compared to HD or PD, although this may in part reflect a selection bias.
- No consensus regarding the relative survival of diabetic patients with diabetes and ESRD managed on HD vs. PD. Base decision on patient's personal preferences, co-morbidities, availability and social support network.
- Consider the malnutrition-inflammation syndrome in all dialysis patients. It is associated with poor overall prognosis.
- Survival for patients with diabetes on dialysis has improved but is still quite poor, which is a strong reason to emphasize prevention in earlier stages of diabetic nephropathy.
- Slinin Y, Foley RN, Collins AJ;
Calcium, phosphorus, parathyroid hormone, and cardiovascular disease in hemodialysis patients: the USRDS waves 1, 3, and 4 study.;
J Am Soc Nephrol;
2005; Vol.
16; pp.
1788-93;
ISSN:
1046-6673;
PUBMED: 15814832
Rating:
Basis for recommendation
Comments:Using the USRDS Data Base, this article links disorders of calcium homeostasis with cardiovascular events in HD patients
- K/DOQI Workgroup;
K/DOQI clinical practice guidelines for cardiovascular disease in dialysis patients.;
Am J Kidney Dis;
2005; Vol.
45; pp.
S1-153;
ISSN:
1523-6838;
PUBMED: 15806502
Rating:
Basis for recommendation
Comments:Practice guidelines for evaluation and management of cardiovascular disease in ESRD patients.
- National Kidney Foundation;
K/DOQI clinical practice guidelines for bone metabolism and disease in chronic kidney disease.;
Am J Kidney Dis;
2003; Vol.
42; pp.
S1-201;
ISSN:
1523-6838;
PUBMED: 14520607
Rating:
Basis for recommendation
Comments:K/DOQI guidelines for mineral bone metabolism in ESRD.
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