RENAL Flashcards
_% of our lean body mass is made up of our TBW
65% of lean body mass is made up of TBW
ECF: 20-25% of TBW
> Interstitial fluid: 15%
> Plasma: 5%
ICF: 30-40% of TBW
ECF: _% of TBW
ICF: _% of TBW
65% of lean body mass is made up of TBW
ECF: 20-25% of TBW
> Interstitial fluid: 15%
> Plasma: 5%
ICF: 30-40% of TBW
Consequence of hyponatremia
Brain swelling
Brain cell swelling is responsible for most of the symptoms of hyponatremia. Neurologic symptoms of hyponatremia include anorexia, nausea, emesis, malaise, lethargy, confusion, agitation, headache, seizures, coma, and decreased reflexes. Patients may have hypothermia and Cheyne-Stokes respirations. Hyponatremia can cause muscle cramps and weakness; rhabdomyolysis can occur with water intoxication.
Consequence of hypernatremia
Brain hemorrhage
Consequence of rapid correction of hyponatremia
Central pontine myelinosis (CPM)
Osmotic demyelinating syndrome
CPM is more common in patients who are treated for CHRONIC hyponatremia than in those treated for acute hyponatremia. Presumably, this difference is based on the adaptation of brain cells to the hyponatremia. The reduced intracellular osmolality that is an adaptive mechanism for chronic hyponatremia makes brain cells susceptible to dehydration during rapid correction of the hyponatremia, and this may be the mechanism of CPM. Even though CPM is rare in pediatric patients, it is advisable to avoid correcting the serum sodium concentration by >12 mEq/L/24 hr or >18 mEq/L/48 hr.
Correction of hyponatremia must not exceed _
10meqs/L/24hrs OR not more than 18meqs/L/48hrs (Nelson)
Correction of hypernatremia _
by <10meqs/L/24hrs (Nelson)
<12meqs/L/24hrs
Hyperkalemia correction
GICKS-L
- Glucose
- Insulin
- Calcium gluconate - WILL NOT DEC POTASSIUM BUT WILL STABILIZE THE HEART
- Kayexelate
- Salbutamol / Steroids
- Lidocaine / Loop diuretics
Frequent etiology of acute hemorrhagic cystitis
> Frequently caused by E. coli
RARE in children
Pyelonephritis characterized by giant cells and histiocytes
A. Acute hemorrhagic cystitis
B. Eosinophilic cystitis
C. Xanthogranulomatous pyelonephritis
D. Interstitial cystitis
C. Xanthogranulomatous pyelonephritis
Causes of FALSE NEGATIVE hematuria on dipstick
Presence of formalin and high urinary concentration of Vitamin C
Causes of FALSE POSITIVE hematuria on dipstick
Alkaline urine (pH >8)
(same for proteinuria)
Most common chronic glomerular disease in children
IgA Nephropathy
> predominance of IgA within mesangial glomerular deposits in the absence of a systemic disease
Primary treatment of IgA nephropathy (2)
- Control BP
- Proteinuria management
BP medications for IgA Nephropathy
ACEi and ARBs
> effective in reducing proteinuria and retarding the rate of disease progression when used individually or in combination
If ACEi and ARBs fail- add corticosteroids
> reduce proteinuria and improve renal
function in those patients with a glomerular filtration rate >60 mL/min/m2.
Acute post-strep GN:
1. Hypertension resolves _ wks after infection
2. Proteinuria resolves _
3. Hematuria is persistent _
4. Serum C3 resolves after _
> Urinary protein excretion and hypertension usually normalize by 4-6 wk after
persistent microscopic hematuria can persist for 1-2yr after the initial presentation.
Serum C3 normalizes after 6-8wks
Classic histopathologic finding in HIV-associated nephropathy
Focal segmental glomerulosclerosis
FALSE NEGATIVE RESULTS FOR PROTEINURIA (3)
- Low pH (<4.5)
- Diluted urine (sp <1.005) or large volume of UO
- Disease states in which predominant protein is NOT albumin
FALSE POSITIVE RESULTS FOR PROTEINURIA (5)
- High pH >7.0
- Highly concentrated urine
- Contamination w blood
- Presence of pyuria
- Prolonged dipstick immersion
Features of NEPHROTIC syndrome (4)
EPAL
1. Edema (most common presenting symptom)
2. Proteinuria (>40mg/m2/hr or >3.5g/24hr or UPCR >2-3)
3. Albuminemia (hypo, <2.5g/dl)
4. Lipidemia (hyper, cholesterol >200mg/dL)
Most common cause of nephrotic syndrome in children
Minimal Change Disease
> most are steroid-sensitive
Mainstay treatment of Minimal Change Disease.
Alternative treatment? (6)
Prednisone: 2mkday or 60mg/m2/day single daily dose for 4-6 weeks.
Taper to 15mkday or 40mg/m2/day alternate every other day.
> 80-90% respond in 3 weeks
> Majority will respond after 5 weeks
Alternative Treatment:
1. Cyclophosphamide
s/e: Neutropenia
2. Calcineurin inhibitors (Tacrolimus, Cyclosporine)
3. Mycophenolate mofetil
4. Levasimole
5. Rituximab
6. AEi ARBs
Calcineurin & MMF- once discontinued, can cause proteinuria