A 48 year old carpenter complains of itching, nausea, and fatigue for 2 months. He has not seen a doctor in over 20 years. When he was in the army, he was told that he had high blood pressure that would require treatment, but he never followed up on this. There is no family history of renal disease or diabetes.

Physical examination: thin appearing male, wt 60 kg; BP 210/120, P 90, regular

fundi show AV nicking and cotton wool exudates

cardiovascular: JVD of 6 cm at 45 degrees, lateral ad displaced PMI and an audible 3 component friction rub. no murmur, S3 or S4;

abdomen: no ascites;

extremities: 2+ pedal and pretibial edema

Neuro: alert and oriented, but slow to respond and mildly confused; absent ankle reflexes and decreased vibration and position sense; normal muscle strength and tone

Urinalysis: 1+ protein, no glucose or blood, 2 3 hyaline casts

24 hour protein excretion: 550 mg; creatinine excretion 1300 mg

Labs:

Creatinine 11.8 BUN 188

Na 139 K 5.7 Cl 103 HCO3 15

Ca 7.2 PO4 12.1 albumin 3.3 g/dl

Hemoglobin 8.1 MCV 92 WBC 4.0 Platelets 250K

Renal ultrasound small kidneys (7 cm, normal is 10-11) with marked echogenicity

1. Assess his volume status and state why it is disordered.

Expanded extracellular volume (JVD, rales, edema)

Low GFR leads to retention of Na, water

2. Explain the pathophysiology of his serum electrolyte abnormalities.

• Hyperkalemia: reduced K filtration due to low GFR
• Gap metabolic acidosis (probable, no ABG!): retention of acids (PO4, SO4). There may also be a concurrent nongap acidosis due to reduced ammoniagenesis in the face of reduced nephron mass.

3. How would you classify his disease? (acute/chronic, glomerular/non-glomerular) based on the urine findings? Should a renal biopsy be done to better define this? What would it likely show?

• Ultrasound suggests chronic kidney disease (CKD—use new terminology)
• urinalysis: probably non-glomerular (hypertensive or interstitial)
• No renal biopsy; it would show a collagenous, scarred interstitium and sclerotic glomeruli, seen in many causes of CKD.

4. What is the significance of the pericardial friction rub? Of the neurologic findings? How would you treat them?

The friction rub and peripheral neuropathy are both signs of uremic pericarditis and uremic neuropathy, both indicating need for dialysis.

5. What is the cause of this patient's bone disease? How might it have been prevented?

• Osteitis fibrosa cystica due to secondary hyperparathyroidism (review pathophysiology)
• Lowering serum phosphate with sevalmer or CaCO3 and supplying 1,25 dihydroxy vit D is the treatment.

6. Why is this patient anemic? How can you treat this?

Anemia is due to lack of EPO, poor marrow response to EPO, and shortened RBC lifespan (30 days). Dialysis can correct anemia, but EPO is now given in almost all patients.

7. How might all these symptoms have been prevented?

Blood pressure control to under 130/90. If the original cause of CKD was glomerular disease, then and ACEi or ARB would have had a separate benefit, as would protein restriction to 0.6-0.8 gm/kg/day. Given his urine protein of under 1 gram, however, BP control would have been the best preventative maneuver.

Earlier referral to a nephrologist would have allowed for preparing for dialysis or transplantation before the onset of uremic symptoms.

8. How much will renal function improve after better blood pressure control is attained?

Given the small kidneys on ultrasound, the prognosis is poor for any significant recovery. There will be progression to stage 5 CKD and renal replacement therapy.

9. What kind of diet would you prescribe for this patient? Would this diet likely improve his symptoms? Would it likely improve renal function?

a) Restrict sodium, potassium, protein, and phosphorus

b) This may improve his symptoms of fluid overload and uremia, but it will not improve his renal function.

10. Assuming there is no change in renal function with your interventions, what are his long-term therapeutic options? Is one better than the other?

Hemodialysis (center-based or home)
Peritoneal dialysis
Renal transplantation (living or cadaveric)

Briefly discuss the advantages and disadvantages, as well as the risks and exclusions of these.