Renal Failure

1. In patients with chronic renal failure ensure they are aware of their diagnosis and its implications.

2. In any patient mitigate the risks of precipitating renal failure when investigation and treatment combinations are likely to be harmful (e.g., metformin and contrast dye, bowel preparation).

3. When prescribing drugs to a patient in renal failure:

   • Determine drug safety (e.g., interactions, dose adjustments, metabolic considerations)

   • Adjust doses when appropriate (e.g., ACE inhibitors, angiotensin II receptor blockers, metformin, allopurinol, antibiotics, low molecular weight heparin, direct oral anticoagulants)

   • Monitor the impact of the drug on the renal function more frequently

4. Advise patients with existing moderate or severe renal failure to pay close attention to hydration (e.g., when travelling, elderly patients in hot weather, when ill) to avoid exacerbating their condition.

5. Advise patients with existing renal failure to avoid certain over-the-counter treatments (e.g., NSAIDS, herbals, supplements) as they may worsen their condition.

6. In patients with moderate or severe renal failure provide anticipatory guidance that if they become ill and cannot maintain fluid intake they should:

   • Stop certain medications promptly (e.g., ACE inhibitors, diuretics)

   • Seek prompt reassessment

7. In a patient with an exacerbation of their renal failure (acute on chronic renal failure):

   • Correct factors (e.g., hydration, pneumonia, congestive heart failure, urinary retention)

   • Stop drugs that might be aggravating the situation (e.g., ACE inhibitors, metformin)

   • Determine the appropriateness of restarting medications, once renal function has stabilized

8. Monitor patients with renal failure periodically, as some patients will worsen over time.

9. For patients with renal failure determine, based on patient factors and local resources, if and when consultation is required (e.g., progressive renal failure, bone disease, refractory anemia, mild renal failure in a young person).

10. Ensure those involved in consultant care of patients with renal failure are aware of other important health considerations that may affect decision making around treatment (e.g., patient preferences, frailty, malignancy, consideration of dialysis in patients with cognitive impairment).

Chronic Kidney Disease (CKD) Definition

• Decreased kidney function (eGFR<60) or kidney damage (urinary albumin) for three or more months

Screening

• Hypertension

• Diabetes

• Age 60-75 with Cardiovascular disease

• Age 18+ First Nations, Inuit, Metis

• Other: Hereditary kidney disease, vasculitis, auto-immune (SLE)

Note: Age alone is NOT an indication for screening

Diagnosis

• eGFR and urine ACR (Albumin-to-Creatinine ratio)

  • If eGFR <60, repeat test in 3 months (or sooner if suspect clinical concern for rapid decline)

    • Adjust for black patients (eGFR multiplied by 1.21)

  • If urine ACR ≥ 3 mg/mmol, repeat total of three times in next three months (at least 2 out of three should be elevated to diagnose)

• Consider

  • Acute illness/acute kidney injury (AKI) which may require more rapid evaluation

  • Reversible causes (NSAIDs, contrast, BPH/urinary retention)

Extended work-up

• Once CKD diagnosed,

  • Urine R+M (urinalysis and microscopy), electrolytes

  • Repeat eGFR and urine ACR q6 months

• If eGFR<60

  • UA, CBC, HBsAg, HBcAb, HBsAb, PPD

  • If UA 2+ blood/moderate or >10RBC/hpf, suspect autoimmune, anemia, or hypercalcemia

    • Add C3, C4, ANA, ANCA, SPEP, Ig's, free light chains

  • If history of stones, obstruction, frequent UTIs, family history PCKD, gross hematuria

    • Renal ultrasound

• Consult nephrology if

  • eGFR<30

  • ACR>60

  • Progressive decline in eGFR

  • Unable to achieve blood pressure targets

  • Electrolytes abnormalities (potassium)

  • RBC casts or hematuria >20RBC/hpf

Management

• Lifestyle

  • Smoking cessation

  • Healthy weight (nutrition, exercise)

  • Diet modification if eGFR<60 (not on dialysis)

    • Limit sodium (<2g/day or <5g salt/day), protein (0.8g/kg/day), phosphate (0.8g/day), calcium (1.5g/d), potassium (1.5g/d)

• Manage hypertension (sBP<120 as per KDIGO 2021, or <130/80 for transplant and diabetic)

  • ACEI or ARB (Consider in non-hypertensive if Urine ACR >30mg/mmol)

    • Follow creatinine and potassium 2 weeks after starting

      • Stop if eGFR >25% drop from baseline

• Manage diabetes (A1c<7)

• Manage hyperlipidemia

  • Statin if

    • ≥50 years old

    • ≥18 years old AND diabetes or CAD or CVA or 10 year Framingham risk >10%

• Renally dose medications

• Minimize further kidney injury

  • Avoid NSAIDs, Aminoglycosides, Lithium, contrast media

  • Sick Day Medications list (to avoid if unable to maintain hydration)

    • SADMANS (Sulfonylureas, ACEI, Diuretics, Metformin, ARB, NSAIDs, SGLT2i)

• Consider Vaccination

  • Influenza annually

  • Pneumococcal with repeat five years after

Management of Complications

• Volume overload

  • Restrict dietary sodium (eg. <2g/d)

  • Diuretic therapy (usually daily loop diuretic, eg. furosemide 80mg)

• Hyperkalemia

  • Low-potassium diet (<1.5g/d)

  • Avoid medications that raise serum potassium (NSAIDs)

• Metabolic acidosis (low serum bicarbonate)

  • Sodium Bicarbonate (NaHCO3) 1000 mg BID to maintain normal serum bicarbonate (>20-22mEq/L)

• Hyperphosphatemia

  • Restrict dietary phosphate (<0.8g/d)

  • Phospate binders (eg. Sevelamer 800mg PO TID meals)

• Hyperparathyroidism

  • Treat hyperphosphatemia, vitamin D deficiency

  • If >150-200pg/mL, consider calcitriol or vitamin D analog

    • Do not use calcitriol if serum phosphate or corrected serum total calcium is elevated

    • Adjust dose to maintain PTH <150pg/mL

• Hypertension

  • Sodium restriction

  • ACEi/ARB

  • If edema, loop diuretic +/- thiazide diuretic

  • If no edema, diuretic or CCB (consider non-DHP CCB in proteinuria)

  • Resistent hypertension, consider spirinolactone

• Anemia

  • Work-up: CBC, retic, iron studies, ferritin, B12/folate, r/o GI loss

  • Replete iron stores if TSAT ≤30% and Ferritin ≤500ng/mL

    • eg. Venofer 300 mg IV q 2 weeks x 3 doses

  • If Hb<90 and iron replete or treated for iron deficiency consider Erythropoiesis-stimulating agents (ESA)

    • Aranesp 0.45 mcg/kg/week

      • Adverse: CVA, AVF clotting hypertension, cancer recurrence

      • Target Hb 100-115

  • Monitor Hb monthly until stable, Fe q3 months

• Decrease in EGFR

  • Progression of disease

  • Hypovolemia (vomiting, diarhea, excessive diuresis)

  • UTI

  • NSAID, medications

  • Obstruction

Complications of end-stage renal disease

• Pericarditis/pleuritis

• Uremic encephalopathy/neuropathy (confusion, asterixis, myoclonus, wrist/footdrop, seizures)

• Uremic bleeding

• Fluid overload refractory to diuretics (CHF/LVH)

• Hypertension poorly responsive to medications

• Metabolic disturbances

  • Hyperkalemia

  • Hyponatremia

  • Hyper/hypocalcemia

  • Hyperphosphatemia

  • Metabolic acidosis

• Malnutrition

Other Complications

• AKI

• Drug toxicity

• Infection

• Hypothyroidism

Medications in Renal Failure

Analgesia

• Encourage non-pharmacological

• Acetaminophen

• Topical capsaicin

• Hydromorphone, fentanyl, methadone, buprenorphine

• Gabapentin, Pregabalin

• TCA (amitriptyline, nortriptyline)

• Avoid NSAIDs, morphine, codeine, tramadol