Acute Kidney Injury (AKI) (Teitelbaum) Flashcards
Cockroft and Gault formula. For what is it used and what is the formula?
Another way to estimate GFR is to estimate the creatinine clearance using the Cockcroft and Gault formula:
Creatinine clearance = [(A) x (140 - age) x weight]/ (72 x SCr)
Where: the creatinine clearance is in ml/min A=l.0 if male, 0.85 if female Age is in years Weight is in kg Serum creatinine is in mg/dL
What is required for a 24 hr createnine clearance test? What equation is used to calculate it?
Patient urine for 24 hour period, blood draw to determine plasma levels of creatinine.
ClCr = (UCr) V/ PCr where
ClCR = Creatinine clearance in mL/min UCR = Urine creatinine in mg/dL V = urine flow rate -->24hr urine volume /1440 (minutes in a day) in mL/min Pcr = plasma creatinine in mg/dL
**note that this is the same equation used to calculate GFR for a generic substance, here we just make it specific for creatinine
x
x
SNGFR is proportional to _____.
PGC
Vasodilation of the afferent arteriole is largely maintained by:
PGE1 and PGI2
Vasoconstriction of the efferent arteriole is largely maintained by:
ATII
Decreased afferent resistance will __ the GFR. What causes this?
Increase. Nitric oxide, prostaglandins E2 and I2, high protein diet/amino acids
Increased efferent resistance will ___ the GFR. What causes this?
Increase the GFR. Angiotensin-II.
Decreased efferent resistance will ___ the GFR. What causes this?
Decrease. ACE inhibitors and ARBs.
Increased afferent resistance will ___ the GFR. What causes this?
Decrease. NSAIDs, adenosine, norepinephrine, endothelin, thromboxane
Na (plasma)
Na- 140 ± 3 mEq/L (Tells you about the relative amount of water in the ECF compared with Na. It tells you nothing about total body Na; best considered as an indirect but readily available assessment of plasma osmolality that is accurate under most (but not all) circumstances).
K (plasma)
K- 4.5 ± 0.6 mEq/L (Tells you about plasma K; relatively poor indicator of total body K).
Cl (plasma)
Cl- 104 ± 3 mEq/L (Generally considered a passive anion; used in the anion gap calculation as described below).
CO2 (plasma)
Total CO2 (tCO2)- 27 ± 2 mEq/L (Total CO2 content of blood; about 3 mEq/L higher than the arterial HCO3- because of dissolved CO2. Used for calculation of anion gap).
Glucose (plasma)
Glucose (Fasting)- 90 ± 30 mg/dL
Creatinine (plasma)
Creatinine- 1.0 ± 0.3 mg/dL (Used to estimate renal function; reciprocal (1/cr)
directly proportional to CrCl and, indirectly, to GFR).
BUN (plasma)
BUN- 12 ± 4 mg/dL
Phosphorus (plasma)
Phosphorus- 4.0 ± 1.0 mg/dL
Ca (plasma)
Calcium- 9.5 ± 1.0 mg/dL
Cholesterol (plasma)
Cholesterol- 140-200 mg/dL
Osmolality (plasma)
Around 285 ± 3 mosm/kg H2O (Direct measurement of plasma osmolality;
difficult to obtain in a short time from a clinical lab).
Azotemia:
Buildup of nitrogenous wastes in the blood; i.e. Blood Urea Nitrogen (BUN) and serum creatinine are increased.
Oliguria
Urine volume is
Anuria
Urine volume is
