Nephrology Flashcards
What is the pH for measuring acidemia or alkalemia
7.4
What is the CO2 content of the body?
40
Anion gap formula? Normal?
Na-Cl-bicarb; 12 is normal
Why do you always calculate anion gap?
Always check it because if you have an increased anion gap acidosis then you always have anion gap acidosis nomatter what else is going on
What do you do after you identiy a respiratory acidosis?
- 7.4 - (dimes x 0.08) = pH if acute
- 7.4 - (dimes x 0.04) = pH if chronic
What do you do after you after you figure out if the acidosis is acute or chronic?
- 24+ (dimes*1) = expected bicarb if acute
- 24 + (dimes x 3) = expected bicarb if chronic
What do you do after determining that there is a respiratory alkalosis?
Dime changes in CO2 to determine chronicity
- 7.4 - (dimes x 0.08) = pH if acute
- 7.4 - (dimes x 0.04) = pH if chronic
What do you do after determining the chronicity of a respiratory alkalosis?
Dime changes in CO2
- 24-(dimes x 2) = Expected bicarb if acute
- 24-(dimes x 4) = expected bicarb if chronic
What do you do after checking the anion gap in metabolic acidosis?
Expected CO2 using winters formula
- Expected CO2 = Winters = (Bicarb x 1.5) + 8 +/- 2
What do you do after doing winters formula in metabolic acidosis?
Add back method
- Current anion gap - normal anion gap = x
- X + current bicarbs = needed value
- If this value is over 24 = metabolic alkalosis
- If this value is under 24 then there is a metabolic acidosis
Causes of anion gap acidosis?
MUDPILES
- Methanol
- Uremia
- DKA
- Propylene
- Iron
- Lactic acidosis
- Ethylene glycol
- Salicylates
What are the causes of Non gap acidosis?
RTA or diarrhea depending on the urine anion gap
What is the normal urine chloride?
10
What is volume responsive metabolic alk?
- Diuretics, dehydration, emesis, NG suction
- Cl under 10 (because tubes can reabsorb Cl)
UCl > 10 and HTN is caused by
Inappropriate aldosterone
UCl >10 and no HTN is caused by
Genetic diseases
Euvolemic hyponatremia causes
RATS
- RTA
- Addisons
- Thyroid
- SIADH
Formula for serum osmoles
Serum osmoles = (2 x Na) + Glucose/18 + Bun/2.8
EKG changes in hyperkalemia
“Everything gets bigger”
- Peaked T waves
- Prolonged QRS
- PR interva lincrease
Treatment of hyperkalemia
C BIG K DIE
- C: Calcium - stabilize myocardium
- B: Bicarb - Shifts K into cells
- IG: Insulin and glucose - Shift K into cells
- K: Kayexalate - Decreased K
- D: Dialysis - Decreased K
Hypokalemia causes
Renal losses
- Hyperaldosterone
- Loop diuretics
- Thiazides
GI losses
- Vomiting
- Diarrhea
What do you do if there is hypokalemia on labs? What do you do if confirmed?
Recheck K and check anEKG for findings
- If confirmed replete at 10 mEq/hr by peripheral line and 20 mEq/hr by central line
GFR ratings in kidney failure?
- I: Over 90
- II: 60-90
- III: 30-60
- IV: 15-30
- V: Under 15
A1C and glucose goals of people on insulin
A1C under 7 and bG 80-110
Complications of renal failure and corresponding treatments
- Anemia: EPO and iron with goal hemoglobin of 11-12
- Scondary hypoparathyroidism: Phosphate binders like sevelamer and cincalcet
- Volume overload: Loops and hemodialysis
- Metabolic acidosis: Bicarb pills
Acute renal failure presentation. What is the first thing you should notice?
Elevated creatinine or decreased urinary output
Causes of prerenal acute kidney injury
- Pump: CHF, MI
- Fluid: Diarrhea, dehydration, diuresis, bleeding
- Pipes: Nephrotic, cirrhosis, gastrosis
- Clog: FMD, RAS
Intrarenal causes of acute tubular necrosis
- Prolonged ischemia
- Toxins (drugs, myoglobin, Ig)
- Contrast induced
Intrarenal causes of acute interstitial nephritis
- Allergic (NSAIDs and beta lactams)
- Infection - pyelo
- Infiltrative (sarcoid, amyloid)
Glomerulonephritis causes
- Glomerular disease
Labs to check in acute renal failure? Treatment?
- BUN:Cr Under 20
- UNa < 10
- FENa <1%
- Tx: IVF or Diuresis
How is postrenal kidney injury diagnosed? Treatment?
- Ultrasound (Hydroureter and hydronephrosis)
- Tx: Stent or remove obstruction
If you suspect intrarenal acute kidney injury, what labs do you check?
Urinalysis, (look for casts) and do a biopsy if youre really really curious
Indications for dialysis
AEIOU
- Acidosis
- Electrolyte imbalance
- Ingestion of toxins
- Overload (CHF, Edema)
- Uremia (Pericarditis)
Contrast induced ATN is prevented by what?
Hydration, prophylactic N acetyl cysteine, stopping ACEs, ARBs and duretics
Phases of Acute Tubular Necrosis
- Prodrome: Creatinine rises but urine output remains the same
- Oliguric phase: Creatinine rises and urine output plummets
- Polyuric phase: Patient pees a lot
Treatment of prerenal azotemia
IVF if dry, diuresis if wet
