Rapid Acquisition Of Key Nephrology Concepts

Defective enzyme

21-hydroxylase

3β-hydroxysteroid dehydrogenase

Cholesterol desmolase

Aldosterone synthetase

Incidence

Most common.

Rare.

Rare.

Rare.

Aldosterone

Deficient

Deficient

Deficient

Deficient

Cortisol production

Deficient

Deficient

Deficient

Normal

ACTH

Loss of feedback inhibition.

High.

Loss of feedback inhibition.

High.

Loss of feedback inhibition.

High.

Normal feedback inhibition.

Adrenal hyperplasia

Yes

Yes

Yes

No

Genital ambiguity

In females

In females

In females

No

Clinical features

Children with failure to thrive.

Hyponatremia

Hyperkalemia

Acidosis

Hypotension

Elevated metabolites

17-hydroxyprogesterone.

DHEA

Corticosterone.

Treatment

Oral hydrocortisone.

9α-fludrocortisone. 

9α-fludrocortisone.

Condition

Maternal Effect

Fetal Effect

IgA Nephropathy

• Hypertension, Proteinuria - Worsened.

Premature delivery

Diabetic Nephropathy

• No increased risk of progression.
• Gestational diabetes - 10% risk of microalbuminuria by 50 years.

Increased perinatal mortality in overt nephropathy.

Lupus Nephritis

• 6 months of remission, prednisolone < 20 mg/day.
• Flare - 30% during pregnancy, 10% postpartum.
• Contraindicated medications - MMF, cyclophosphamide.
• If the pregnant woman is on MMF and is symptoms free from the past 6 months, convert the drug to azathioprine. 
• Safe Drugs- Azathioprine, steroids, tacrolimus.
• Prior histological class - No effect on outcome.
• Poor outcome - Creatinine >0.9, hypertension, APLA (Thrombogenic stage associated with repeated pregnancy loss), flare.

Anti Ro, Anti La antibody in mother: Foetal heart block, neonatal cutaneous lupus.

Maternal HCQ can be prevented.

Reflux Nephropathy

• Outcome dependent on - Creatinine, hypertension.
• Increased preeclampsia, IUGR - Kidney with scarring Increased risk of UTI.

• Discussed in cytouretric reflex.

40% have VUR

Pre Pregnancy

• Discuss risks of pregnancy (Miscarriage, fetal death, fetal growth restriction, prematurity, preeclampsia).
• Ensure all medications are safe during pregnancy.

• Avoid contraindicated drugs - MMF or mTOR inhibitors.

• Aspirin: 75 to 150 mg daily - Reduces the incidence of preeclampsia.
• Folic acid: 5 mg daily.

During Pregnancy

Dialysis

• 20 hours per week in four or more sessions.
• Generally, a 4 hours session thrice a week = 12 hours of session in CKD.
• In pregnancy, 5 or 6 sessions per week.
• Aim for predialysisBUN <40 mg/dl (Serum urea 15 mmol).
•  may increase because of hypercoagulability Heparin requirement of pregnancy.
• Reason: CKD itself causes hypercoagulability.

Anaemia

• IV iron to maintain iron stores.
• Dose of ESA to achieve hemoglobin 10 to 11 g/dl.

Bicarbonate

• Adjustoral and dialysate bicarbonate to achieve normal serum bicarbonate for pregnancy (18 to 72 mmol/1).
• Reason: Pregnancy is a condition of chronic respiratory alkalosis due to hyperventilation caused by pressure of the uterus on the lungs.

Nutrition

• Dietician advice to ensure adequate protein and nutrient intake.
• Supplementoral or dialysate phosphate to maintain post-dialysis serum phosphate in the normal range.

Calcium

• Maintain normal serum calcium with additional oral calcium and vitamin D as well as increased dialysate calcium.
• Hypercalcemia is occasionally provoked by placental PTHrP and vitamin D-like substances.

Phosphate

• Supplement oral or dialysate phosphate to maintain post-dialysis serum phosphate in the normal range.
• Every dialysis session removes 800 mg/dl of phosphate - 12 hours of the dialysis session.
• If excess time is taken for the session it might remove the excess phosphate - Hypophosphatemia.

After Pregnancy

• Return to the usual dialysis schedule immediately.
• Readjust dry weight and antihypertensives weekly for 6 weeks.