CLINICAL USE OF CLINICAL USE OF DIURETICSDIURETICS

PATHOGENESIS AND TREATMENT OF PATHOGENESIS AND TREATMENT OF REFRACTORY EDEMAREFRACTORY EDEMA

Determinants of diuretic response - site of action, Determinants of diuretic response - site of action, antinatriuretic forces, fall in BP, rate of drug antinatriuretic forces, fall in BP, rate of drug excretionexcretion

excess sodium intakeexcess sodium intake decreased or delayed intestinal absorptiondecreased or delayed intestinal absorption decreased drug entry into lumendecreased drug entry into lumen increased distal reabsorptionincreased distal reabsorption decreased loop sodium delivery (low GFR and/or decreased loop sodium delivery (low GFR and/or

enhanced proximal reabsorptionenhanced proximal reabsorption

Match the clinical setting with the preferred Match the clinical setting with the preferred diureticdiuretic

Recurrent nehprolithiasis (Ca+2)Recurrent nehprolithiasis (Ca+2) hepatic cirrhosis with asciteshepatic cirrhosis with ascites metabolic alkalosis in CHFmetabolic alkalosis in CHF hypercalcemiahypercalcemia Hyponatremia due to SIADHHyponatremia due to SIADH

QuestionQuestion

The appropriate use of diuretics may induce The appropriate use of diuretics may induce or exacerbate effective circulating volume or exacerbate effective circulating volume depletion in which of the following depletion in which of the following edematous states?edematous states?– CHFCHF– nephrotic syndromenephrotic syndrome– renal failurerenal failure– hepatic cirrhosis and asciteshepatic cirrhosis and ascites

QuestionQuestion

What is the simplest way to detect this What is the simplest way to detect this change?change?– Measurement of urine Na concentrationMeasurement of urine Na concentration– measurement of BUNmeasurement of BUN– estimation of JVPestimation of JVP– measurement of systemic BPmeasurement of systemic BP

CASECASE Previously well 45 YO male, acute onset of crushing CP Previously well 45 YO male, acute onset of crushing CP

and dyspnea. Medical eval confirms AMI and Pulm and dyspnea. Medical eval confirms AMI and Pulm edema. Treated with O2 and diuretics he becomes edema edema. Treated with O2 and diuretics he becomes edema free. Weight has fallen by 3 KG within 24 hours and his free. Weight has fallen by 3 KG within 24 hours and his estimated JVP is less than 5 cm H2O. Now he is oliguric, estimated JVP is less than 5 cm H2O. Now he is oliguric, urine Na < 10. BUN increased from 10 to 28mg/dl.urine Na < 10. BUN increased from 10 to 28mg/dl.– What are 2 most likely causes of oliguria and increase in BUN?What are 2 most likely causes of oliguria and increase in BUN?– Would a normal EF distinguish between these possibilities?Would a normal EF distinguish between these possibilities?– Does low JVP exclude cardiac dysfunction?Does low JVP exclude cardiac dysfunction?– Is total ECF >, =, or < normal?Is total ECF >, =, or < normal?– What modes of therapy might return BUN and urine output to What modes of therapy might return BUN and urine output to

normal?normal?