Nephro SAQ

Question 1

Old woman flu-like symptoms, self-bought medicinal oil over the counter 1w ago. Now confused and tachypnoea. Uncooperative to PE. Normal CNS (able to move 4 limbs, no focal neurological deficit and neck stiffness) and RS (clear chest) PE.
Blood gas:
Sodium 136, potassium 6, chloride 102, bicarbonate 8
Urea 12.7, Creatinine 212
pH 7.26

1. Describe the acid-base disorder in the blood gas.
2. Name 4 investigation to determine the cause.
3. 2 immediate measure to lower plasma K.
4. If the blood gas shows marked respiratory compensation and hyperventilation, what is the most likely cause?

Answer 1

1. High anion gap metabolic acidosis (pH < 7.26 so metabolic acidosis), (136- (102 +8)) = 26 (above normal anion gap)
2. Serum salicylate level, urine toxicology, lactate level, blood glucose and ketones
3. IV 10% calcium gluconate, IV regular human insulin, K, resonium C, nebulized salbutamol
4. Salicylate poisoning

Question 2

A young lady with known MVP was diagnosed with infective endocarditis. Blood culture showed streptococcus viridians and she was placed on ampicillin and gentamicin. 2 weeks later, she developed shortness of breath and ankle swelling. She developed erythematous macular rash over on trunk and LL. Creatinine level was raised. Urinalysis showed positive RBC 1+ and protein 1+.
1. Name 3 possible differentials
2. Name 4 non-invasive investigations for confirmation of diagnosis
3. Name 3 indications that would require temporary dialysis for this patient

Answer 2

1. Acute interstitial nephritis due to ampicillin
   Post infective endocarditis glomerulonephritis
   Septic emboli from IE to renal artery
   Acute tubular necrosis (TIN) due to gentamicin (aminoglycoside)
   DRESS causing AKI
2. Urine for WBC cast, eosinophilia, RBC cast for AIN and GN
   CBC for eosinophilia
   C3/4 for glomerulonephritis
   Renal artery ultrasound for septic emboli
   Serum gentamicin level (trough level)
3. Refractory hyperK >6, refractory metabolic acidosis <pH<7.1) but c/i to HCO3, refractory pulmonary edema, uremic pericarditis/encephalopathy

Question 3

F/35 with CKD due to IgA nephropathy. Husband with good past health wants to donate his kidney.
1. 2 prerequisites
2. Like recipient and donor 3, how many HLA mismatches?
3. Patient given steroid, cyclosporin and MMF after transplant. MoA of cyclosporin
4. 2 AE of MMF
5. Patient developed elevated creatinine on post-transplant day 12. (Table showed Cr level and cyclosporin trough up level from day 1 to 12, Day 12 trough pending) 3 reasons for elevated creatinine on day 12

Answer 3

1. No CJD, degenerative neurological disease. No history of IVDU. No HIV+ve. No malignant disease (except primary BCC, carcinoma in situ of uterine cervix), known cause of death
2. 0 mismatch
3. Inhibit calcineurin, inhibit IL2 synthesis
4. GI upset, VZV infection, teratogenicity, myelosuppression. CMV infection, hypertension
5. Infection: bacterial, viral (BK, JC virus)
   * Urine outflow obstruction
   * Acute rejection
   * Impaired arterial supply (transplant artery stenosis)
   * Calcineurin inhibitor nephrotoxicity (hence measure trough level)
   * Nephrotoxicity from other medications e.g. NSAIDs, TCM
   * Renal vein thrombosis

Question 4

Answer 4

a)
Hypovolemia (prerenal cause) due to diarrhea
Calcineurin inhibitor nephrotoxicity
Antibiotics tubulointerstitial nephritis
NSAID induced nephrotoxicity
b) Optomize preload for hypovolemia: normal saline 500-1000ml over 1-2 hours
c)
d) Hypovolemic hypernatremia due to excessive renal loss of water
e) Volume repletion 1/2 NS or NS than correct tonicity: PO or IV hypotonic fluids

Question 5

Answer 5

a) Iron profile (early iron deficiency anemia)
b) Reticulocyte cunt, ferritin/Tf saturation and serum B12/folate to exclude non renal causes of anemia
c)
Hb<10: start on erythropoiesis stimulating agents e.g. mircera
Iron supplementation to be given before ESA when iron deficient. Choice: oral FeSO4, IV Fe sucrose
dietary retriction of phosphate containing food. Calcium containing phosphate binders: calcium acetate

Question 6

A 30+ year old man presents with significant oedema of the lower limbs after a URTI. The following laboratory results are obtained (urine ++ protein).
a. What is the clinical diagnosis?
b. List 3 complications of this condition
He is given furosemide by his GP but his condition doesn’t improve.
c. What is the problem with the medication given by the GP
d. What serological markers can be used to aid diagnosing the problem?
e. What is the likely histological diagnosis
f. What treatment is usually given for this diagnosis?

Answer 6

a. nephrotic syndrome
b. AKI, hypovolemia, increased risk of infection (loss of Ig), increased thrombotic risk, hyperlipidemia (to compensate for loss of albumin)
c. Removes fluid but does not relieve the oncotic pressure difference
d.
Minimal change disease
FSGS: anti GBM
Membranous nephropathy: primary (anti PLA2R), secondary. Infection: HBV, HCV, HIV, malaria, syphilis. Drugs: NSAIDs. Class 5 lupus nephritis: serum C3/4, ANA, anti dsDNA
e. Minimal change disease
f. Plasmapharesis (wash out the anti GBM antibdoies) + Oral prednisone (1mg/kg) + oral cyclophosphamide (2-3/mg/kg/day)