Nephrology Flashcards
What is Acute Kidney Injury (AKI)?
Inability to clear waste products, leading to a buildup of ‘uremic’ toxins. Inability to maintain electrolyte & acid-base homeostasis. Inability to maintain water homeostasis.
What are the main causes of AKI?
Pre-renal, Renal, and Post-renal causes.
Give examples of pre-renal AKI causes.
Volume depletion, decreased cardiac output, decreased vascular resistance (sepsis), nephrotic syndrome, liver failure, impaired renal autoregulation.
Give examples of renal AKI causes.
Tubules/Interstitium (ischemic tubular injury, nephrotoxic AKI, acute interstitial nephritis), Glomerulus (post-infectious glomerulonephritis), Blood Vessels (Hemolytic Uremic Syndrome, Renal Vein Thrombosis).
Give examples of post-renal AKI causes.
UPJ obstruction, ureteric obstruction, intraluminal obstruction, bladder obstruction, cancer.
What is the most common cause of childhood Chronic Kidney Disease (CKD)?
Renal dysplasia.
How to manage acute severe hyperkalemia (K+ > 6.5 mmol/L)?
Remove K+ intake, cardiac membrane stabilization (Calcium Gluconate or Calcium Chloride), redistribution strategies (Salbutamol, Glucose & Insulin, Sodium Bicarbonate), Removal of K+ via CVVH or HD.
What ECG features are associated with hyperkalemia?
Tall peaked T waves, flattened/absent P waves, sine wave, prolonged PR interval, widened QRS complex, bradycardia/VTach/VFib.
What medications should be avoided in hyperkalemia?
K+ supplements, K+ sparing diuretics, ACE inhibitors, NSAIDs, Succinylcholine.
What are the indications for dialysis?
A: Acidosis, E: Electrolyte abnormalities (hyperkalemia, hyponatremia, hyperphosphatemia), I: Ingestions, O: Fluid overload, U: Uremia.
What is Multicystic Dysplastic Kidney (MCDK)?
Failure of union of ureteric bud with renal mesenchyme, resulting in a non-functioning kidney replaced by non-communicating cysts. Often involutes by age 5.
Autosomal Dominant Polycystic Kidney Disease (ADPKD) genetics and when does ESRD occur?
PKD1 (75-85% of cases) leads to ESRD in 50s, PKD2 leads to ESRD in 70s.
What are key features of Autosomal Recessive Polycystic Kidney Disease (ARPKD)?
Presents as neonates or infants, high neonatal mortality, oligohydramnios, large echogenic kidneys. All patients have associated hepatic involvement.
How is hematuria defined?
> 5 RBCs per high-power field (HPF) on urinalysis.
What are the signs of Glomerular Hematuria?
Brown or ‘tea-colored’ urine, RBC casts, cellular casts, tubular cells, proteinuria ≥ 2+ on dipstick.
What are the signs of Non-Glomerular Hematuria?
Red-pink urine, blood clots, no proteinuria or ≤ 2+ on dipstick, normal erythrocytes.
How might Glomerulonephritis present?
Asymptomatic microscopic hematuria, asymptomatic microscopic hematuria with proteinuria, acute nephritic syndrome (gross hematuria, AKI, hypertension, edema).
What is Post-streptococcal glomerulonephritis (PSGN)?
Most common pediatric GN worldwide, typically affects children 4-12 years old, related to strep-pharyngitis or pyoderma. Presents with acute nephritic syndrome. Diagnosis supported by low C3.
What is Shiga toxin (+) HUS?
Primarily affects children <5 years of age. Most often caused by Shiga toxin-producing E.coli 0157:H7 (STEC). Bloody diarrhea is the most common presentation.
What are key features of Pneumococcal HUS?
Following invasive S. pneumoniae infection. Presents with severe pneumonia/empyema. Affects infants and young children mostly. High mortality and dialysis rates.
What are key features of Atypical HUS (aHUS)?
Mostly complement mediated from genetic mutations. Often triggered by infections. Recurrent in nature with higher risk of CKD/ESRD.
What are key features of IgA Nephropathy?
‘Syn-pharyngitic’ GN, gross hematuria around time of URTI, often microscopic hematuria between illnesses. Confirmation with renal biopsy.
What are key features of Thin Basement Membrane Disease?
Common cause of persistent or intermittent microscopic hematuria. Kidney Biopsy shows thin glomerular basement membrane.
What are key features of Alport Syndrome?
Hereditary nephritis, often X-linked. Progressive disorder that often leads to kidney failure. Bilateral sensorineural hearing loss, ocular manifestations.
What is considered normal urinary protein excretion?
<100 mg/m2/day or <4 mg/m2/hr.
What is Glomerular Proteinuria?
↑ albumin due to pathological causes (e.g., nephrotic syndrome) or non-pathological/transient causes (e.g., fever, heavy exercise).
What is Tubular Proteinuria?
Low molecular weight (LMW) proteins.
What are the key features of Nephrotic Syndrome?
Proteinuria, Edema, Hypoalbuminemia (<25 g/L).
What is the initial treatment for Nephrotic Syndrome?
Daily prednisone for six weeks followed by alternate day prednisone for an additional six weeks.
List some steroid sparing agents and their side effects.
Cyclophosphamide (oral) - Leukopenia, hemorrhagic cystitis, gonadal toxicity. Mycophenolate Mofetil (MMF) - GI complaints. Tacrolimus or Cyclosporine - Tremor, hyperK, hypoMg, metabolic acidosis, hypertension, AKI.
What is the most important test to determine the etiology of hyponatremia?
Urine osmolality.
How do you manage SIADH?
Identify reversible cause, rule out thyroid & adrenal cause, fluid restriction.
How do you treat Symptomatic Hyponatremia?
3% NaCl.
What are the causes of hypernatremia?
Water loss (Diabetes insipidus, diarrhea), inability to drink/access water.
What should you consider if hypernatremia is present with urine osmolality <600?
Central or nephrogenic diabetes insipidus (DI).
How do you calculate the Anion Gap?
[Na+] – ([HCO3 -] + [Cl-]). Normal AG is 12 +/- 3.
What are the main causes of Non Anion Gap Metabolic Acidosis?
Diarrhea, Renal tubular acidosis (RTA).
What are the key features of Distal RTA (Type 1)?
Defective H+ secretion, associated with hypokalemia, hypercalciuria, nephrocalcinosis & hypocitraturia.
What are the key features of Proximal RTA (Type 2)?
↓ ability to reclaim HCO3, often part of Fanconi syndrome.
What is Fanconi Syndrome?
Loss of bicarbonate, phosphate, glucose, amino acids, sodium, potassium.
What is Cystinosis?
AR lysosomal storage disease with accumulation of cystine dimers in lysosomes.
What are key features of Bartter Syndrome?
Hypokalemia, metabolic alkalosis, hyperaldosteronism, polyuria, hypercalciuria & salt wasting.
What are key features of Gitelman Syndrome?
Hypokalemia, metabolic alkalosis, hypomagnesemia, hypocalciuria, & polyuria. Milder salt wasting compared to Bartter syndrome.
How is hypertension identified?
BP over 134/90 averaged over 3 readings during office visit. Selection of correct-sized cuff is important.
What is White Coat Hypertension?
BP ≥ 95th%ile in the clinic but < 95th%ile by 24-hour ABPM.
What are the most common causes of secondary hypertension in children?
Renal or renovascular causes.
What investigations should be conducted for hypertension?
Blood chemistry, urinalysis, renal ultrasound, fasting blood glucose, lipid profile, echocardiogram, retinal check.
What are the blood pressure goals of hypertension therapy?
Children: < 90th percentile for age, gender, height. Adolescents: < 130/80 mmHg.
What are the first line medications for hypertension with Chronic Kidney Disease?
ACE inhibitor or ARB.
How do you treat Hypertensive Urgency?
Treat with oral (nifedipine) or IV agents (labetolol, nicardipine, esmolol).
What are the first line medications for hypertension with Chronic Kidney Disease?
ACE inhibitor or ARB.
How do you treat Hypertensive Urgency?
Treat with oral (nifedipine) or IV agents (labetolol, nicardipine, esmolol).
How do you treat Hypertensive Emergency?
Reduce MAP by 25% within minutes to 1-2 hrs. Gradual reduction towards normal in 24-48 hrs.
