Renal Flashcards
Clues for ADPKD
Hypertension
Palpable bilateral abdominal masses
Microhematuria
Common complication - Intracranial berry aneurysm (5 - 10% of cases)
Major extra-renal complications of ADPKD
Hepatic Cysts (Most common)
Valvular Heart Disease (Most often mitral valve prolapse & aortic regurg)
Colonic Diverticula
Abdominal Wall & Inguinal Hernias
Thickened Basement Membrane
Sub-Epithelial “Spikes”
Membranous Glomerulonephritis
Mesangial hypercellularity
Membranoproliferative glomerulonephritis
When do we biopsy the kidney in Minimal Change Disease?
If the patient is >10 years old
If the disease is resistant to corticosteroids
Severe symptoms if Sodium <120mEq/L
Profound Confusion
Seizures
Coma
Increased risk of cerebral edema & brainstem herniation
Maximum rate of safely correcting hyponatremia
<=8mEq/L increase over the first 24 hours
Complication of correcting hyponatremia too quickly
Osmotic Demyelination Syndrome
Complication of correcting hypernatremia too quickly
Cerebral Edema
How do you correct electrolyte imbalances of SIADH?
Hypertonic saline
Saline must be more concentrated than urine.
NS has 300 mOsm/kg H2O
1/2NS has 150 mOsm/kg H2O
Desmopresin
ADH Analogue
Treats Diabetes Insipidus
Hyponatremia with Hypovolemia
Adrenal Insufficiency
Treat with IV Hydrocortisone
Hyponatremia with Euvolemia
Think SIADH
Treat with hypertonic saline (gradually)
Sodium Nitroprusside
Potent Vasodilator (Arterial AND Venous) Used in hypertensive emergencies
Contains 5 cyanide groups
Undergoes rapid conversion to cyanide
Then Thiocyanate
Eliminated by kidneys
In CKD patients, can lead to cyanide toxicity
Typical findings of cyanide toxicity
Headache Confusion Arrhythmias Flushing Respiratory Depression
Post-Operative Urinary Retention
Precipitating Event: Bladder distension during general anesthesia or epidural anesthesia use
Inefficient detrusor activity leads to acute urinary retention
Risk increases with age
Risk increases with high fluid intake during surgery
Risk increases with concomitant use of other medications (Opiates, anticholinergics)
Postop Oliguria Rate
<= 0.5mL/kg/hr
In a 70kg patient, that’s 35 mL/hr
Cardiorenal Syndrome
CHF Patient
Volume overload but low CO
Poor renal perfusion
Renal perfusion can improve with loop diuretics
Urine Sediment Analysis - Muddy Brown Casts
Acute Tubular Necrosis
Urine Sediment Analysis - Eosinophils
Acute Interstitial Nephritis
Signs & Symptoms of Hypernatremia
Most common: Lethargy AMS Irritability Seizures
Also:
Muscle Cramps
Muscle Weaknesses
Decreased DTRs
Causes of Hypovolemic Hypernatremia
Renal Losses:
Diuretics
Glycosuria
Extrarenal:
GI Upset
Excessive Sweating
Causes of Hypervolemic Hypernatremia
Exogenous Sodium Intake Mineralocorticoid Excess (Hyperaldo)
Why not use hypotonic fluids (like 1/2 NS or 5% Dextrose) to lower the sodium in a hyponatremic patient?
Hypotonic solutions exit the intravascular space too quickly and cause precipitous drops in sodium (Cerebral Edema)
Hepatorenal Syndrome
Severe Cirrhosis leads to Portal HTN
Leads to increased nitric oxide generation in splanchnic circulation
Leads to systemic vasodilation, reducing peripheral vascular resistance & BP
Leads to renal hypoperfusion & activation of RAAS
Leads to increased water & sodium retention, worsening volume overload
Lab findings of Hepatorenal Syndrome
Similar to prerenal azotemia
Elevated Cr (>1.5mg/dL) Very low urine sodium (<10 mEq/L)
Unremarkable sediment
Does not respond to IV fluids or cessation of diuretics. Renal function continues to decline
Membranoproliferative Glomerulonephritis
Associated with HCV
Acute Renal Vein Thrombosis - Presentation
Abdominal Pain
Hematuria
Most common drug-induced chronic renal failure
Analgesic Nephropathy
Seen in women 50 - 55 yo who use combined analgesics (ASA & Naproxen)
Pappilary necrosis & Chronic tubulointerstitial nephritis most common
Sterile Pyuria
At what level of PaCO2 is CO2 Narcosis seen?
PaCO2 > 60 mm Hg
How do you calculate Anion Gap?
Na - (Cl + HCO3)
Normal is 10 - 14
Cause of hyponatremia with Serum Osmolarity > 290 mOsm/kg
Marked Hyperglycemia
OR
Advanced Renal Failure
Cause of hyponatremia with:
Dilute serum (<290 mOsm/kg) Dilute urine (<100 mOsm/kg)
Primary Polydipsia
OR
Malnutrition (Beer Drinker’s Potomania)
Cause of hyponatremia with:
Dilute serum (<290 mOsm/kg) Concentrated urine (>100 mOsm/kg) Low urine sodium (<25 mEq/L)
Volume Depletion
CHF
Cirrhosis
Cause of hyponatremia with:
Dilute serum (<290 mOsm/kg) Concentrated urine (>100 mOsm/kg) High urine sodium (>25 mEq/L)
SIADH
Adrenal Insufficiency
Hypothyroidism
Treatment for simple asymptomatic renal cyst
Reassurance
Treatment for Renal Artery Stenosis
Ace Inhibitors first
Revascularize if they fail that
Lithium’s effect on ADH
Impairs water resorption in collecting duct
Leads to ADH Resistance
Nephrogenic DI
Most common site for metastatic spread of a Wilms Tumor
Lungs (This is still rare)
Most common cancer in the first year of life
Neuroblastoma
Anywhere in sympathetic nervous system
Typically involves adrenal glands
Abdominal mass that crosses the midline
Systemic symptoms
Abdominal Pain
Lower Extremity Purpura
Arthritis
Hematuria
in a child
HSP
An IgA-mediated vasculitis of small vessels
Renal biopsy demonstrates deposition of IgA into mesangium
Typical presentation of FSGS
Nephrotic Range Proteinuria
Azotemia
Normal-Sized Kidneys
Risk factors for Rhabdomyolysis
Immobilization
Cocaine Abuse
Signs of Lupus
Photosensitive skin
Thrombocytopenia
Glomerulonephritis with significantly low C3
Immune complexes in mesangium or subendothelial space
If Low C3 & C4, it is Lupus, involving an inflammatory reaction.
If normal C3 & C4, it is membranous glomerulonephritis
Cause of metabolic alkalosis with low (<20mEq/L) urine chloride
Vomiting/Nasogastric Aspiration
OR
Prior diuretic use
SALINE RESPONSIVE
Cause of metabolic alkalosis with high (>20mEq/L) urine chloride in a hypervolemic patient
Excess mineralocorticoid activity:
Primary hyperaldo
Cushing’s
Ectopic ACTH production
SALINE UNRESPONSIVE
Cause of metabolic alkalosis with high (>20mEq/L) urine chloride in a hypovolemic or euvolemic patient
Current Diuretic Use (SALINE RESPONSIVE)
OR
Bartter / Gitelman Syndromes (SALINE UNRESPONSIVE)
Treatment for pyelonephritis with an MDR organism
Aminoglycosides (like Amikacin)
This can cause ARF
Muddy Brown Casts on UA
Hallmark of ATN (Nonspecific, but very sensitive)
Casts seen in Chronic Renal Failure
Broad Casts
Waxy Casts
RBC Casts
Glomerular Disease
Vasculitis
WBC Casts
Interstitial Nephritis
Pyelonephritis
Fatty Casts
Nephrotic Syndrome
Hyaline Casts
Asymptomatic patients
Pre-renal azotemia
TB’s effect on the adrenals
Chronic primary adrenal insuficiency
Fatigue
Weakness
Borderline hypotension
Electrolyte abnormalities
Granulomatous causes of adrenal insufficiency
TB Histoplasmosis Coccidioidomycosis Cryptococcosis Sarcoidosis
Hypoglycermia
Hyperkalemia
Eosinophilia
Adrenal Insufficiency
Decreased cortisol
Decreased adrenal sex hormone
Decreased aldosterone
Addison’s Disease
Without aldosterone:
Sodium is excreted, potassium & H+ are retained
Normal anion gap hyperkalemic hyponatremic metabolic acidosis
Normal anion gap
Hyperkalemic
Hyponatremic
Metabolic Acidosis
Lack of aldosterone (likely Addison’s)
Maybe RTA? Not hyponatremic, though
Anticholinergic effect on bladder
Urinary retention
Most common inciting factors of Hepatorenal syndrome
Spontaneous bacterial peritonitis
GI Bleed
Temporizing options for hepatorenal syndrome while awaiting transplant
Midrodrine
Octreotide
Norepinephrine
(Splanchnic vasoconstrictors)
Seizure patient with metabolic acidosis
Postictal lactic acidosis
Transient
Resolves within 90 min
Repeat chemistry in 2 hours
Renal Tubular Acidosis
Group of disorders:
Non-Anion Gap Metabolic Acidosis
Preserved kidney function
Hyperkalemic RTA (Type 4 RTA) - seen in elderly diabetics
Renal Vein Thrombosis from Nephrotic Syndrome
Loss of Antithrombin III in urine
Increases risk of Renal Vein Thrombosis
Most commonly seen with Membranous Glomerulopathy