Question

Stage 3 CKD: Describe the pathophysiology; GFR lab values, manifestations, electrolyte problems, (water imbalances, electrolytes (sodium, potassium, bicarbonate, calcium, phosphate), nitrogen compounds and Vitamin D. What is done to manage CKD at this stage?

Answer 1

• Pathophysiology

1. Chronic kidney disease is characterized by loss of neurons
2. Renal injury causes a decrease in the number of neurons.
3. The remaining normal nephrons respond to the loss by hypertrophy and hyperfiltration.
4. This increases glomerular capillary pressure.
5. This, in turn, damages the nephrons
6. Factors that promote renal damage
   1. dehydration
   2. systemic hypertension
   3. diabetes
   4. Proteinuria
   5. nephrotoxic drugs Ex. aminoglycosides, colistin
   6. history of acute kidney injury
   7. age

GFR lab values - CKD stage 3 - estimated glomerular filtration rate is 30 - 59 ml /min /1.73 m2

Manifestations:

1. patients with GFR > 30 ml/ min/ 1.73 m2 are usually asymptomatic
2. Water and electrolyte abnormalities don't occur
3. however, in the case of cystic renal disease, tubulointerstitial renal disease, nephrotic syndrome have symptoms earlier.
4. Symptoms of uremia are seen in endstage renal disease not in CKD- 3
5. Depression can be present in CKD - 3

Electrolyte problems

1. Water imbalances - Normal, seen in stage 5, not in stage -3
2. Sodium - Normal, defect in sodium management is seen when GFR is < 10 - 15
3. Potassium - Normal. Hyperkalemia is seen when GFR is less than 20 -25.
4. Bicarbonate - The kidney is unable to produce enough ammonia to secrete the endogenous acids. This leads to metabolic acidosis. There is a reduction in the level of bicarb
5. calcium - Hypocalcemia
   1. this develops due to decreased calcium absorption in the intestine
   2. Reduced Vit-D levels
6. Phosphate -
   1. In the initial stages, phosphate retention occurs due to reduced excretion.
   2. As the renal functions fall > parathyroid levels rise > renal excretion of phosphate increase - the phosphate levels reduce.
   3. But in stages higher than 3, the ability of the kidney to excrete phosphate reduces.
7. Nitrogen compound
   1. Increased in nitrogen compound
   2. The nitrogen compound is derived from the breakdown of protein.
   3. The Proximal convoluted tubule converts the nitrogen into ammonia.
8. Vitamin D
   1. Decreased renal synthesis of Vit-D

Management of Stage 3.

• Dietary management
  • cardiovascular risk reduction
  • Patients of CKD are at increase risk of ischemia heart disease
  • Smoking cessation and reduce alcohol consumption
  • start statins ( lipid-lowering agents - atorvastatin)
  • exercise.
• Management of anemia - iron supplements and erythropioten
• Reduce blood pressure - diuretics - thiazide, furosemide.
• Influenza vaccine and pneumococcal vaccine.