Lab-solutely Renal
This equation is used to estimate kidney function and stage chronic kidney disease. Commonly calculated for you on chemistry panels.
What estimated glomerular filtration rate (eGFR)?
The initial bedside test for suspected urinary retention contributing to AKI.
What is a bladder scan?
The anion gap is calculated using this formula.
What is sodium minus chloride minus bicarbonate?
Na⁺ - (Cl⁻ + HCO₃⁻)
[Or (Na⁺ + K⁺) - (Cl⁻ + HCO₃⁻) ]
Acute tubular necrosis due to ischemia or nephrotoxins most often produces these characteristic urinary sediment findings.
What are muddy brown granular casts?
This ECG finding is classically associated with hyperkalemia.
What are peaked T waves?
This is the first laboratory step when a markedly low sodium level is unexpected or inconsistent with the clinical picture.
What is serum osmolality?
Persistent urine albumin-to-creatinine ratio of at least 30 mg/g is an early marker of this common CKD complication.
What is albuminuria?
Diarrhea commonly causes this acid-base disorder.
What is non-anion gap metabolic acidosis?
Red blood cell casts on urinalysis strongly suggest this renal process.
What is glomerulonephritis?
This medication is given first for severe hyperkalemia with ECG changes to stabilize the cardiac membrane.
What is IV calcium?
A patient with diabetes has a rising urine albumin-to-creatinine ratio and preserved eGFR. This represents this stage of diabetic kidney disease.
What is (early) albuminuric diabetic kidney disease?
Grossly painless hematuria in an older adult warrants evaluation for this potentially serious diagnosis until proven otherwise.
What is urothelial malignancy?
In diabetic ketoacidosis, this ratio comparing the change in anion gap to change in bicarbonate helps identify mixed acid-base disorders.
What is delta anion gap / delta bicarbonate?
White blood cell casts are classically associated with this diagnosis.
What is acute pyeloneprhitis?
Overly rapid correction of chronic hyponatremia can cause this potentially irreversible neurologic syndrome.
What is osmotic demyelination syndrome?
In a patient taking an ACE inhibitor or ARB, this degree of creatinine increase from baseline is generally considered acceptable after initiation, provided the patient is otherwise stable.
What is 30%?
Anuria, hydronephrosis, or a markedly distended bladder should raise concern for this reversible cause of AKI.
What is postrenal obstruction?
This condition should be suspected when a patient with high anion gap metabolic acidosis has elevated lactate and a history of alcohol use disorder with recent cessation of intake.
What is alcoholic ketoacidosis?
A patient with severe rhabdomyolysis has heme-positive urine with few red cells and pigmented granular casts. The renal injury is due to this pigment.
What is myoglobin?
Severe symptomatic hyponatremia with seizures is treated emergently with this concentration of saline.
What is 3% hypertonic saline?
In critically ill patients, correcting the anion gap for this factor and lactate improves detection of unmeasured anions compared to the traditional calculation.
What is albumin?
A fractional excretion of sodium below 1% classically supports this diagnosis, although interpretation is limited with diuretic use and CKD.
What is prerenal AKI?
This type of renal tubular acidosis is associated with hyperkalemia and is often due to aldosterone deficiency or resistance.
What is type IV RTA (hyperkalemic distal RTA)?
Broad, waxy casts are classically associated with advanced chronic kidney disease and this urine-flow state.
What is low urine flow?
In hypercalcemia of malignancy, this laboratory finding distinguishes it from primary hyperparathyroidism.
What is suppressed or low PTH?