captopril

CAPTOPRIL RENOGRAPHY INTHE EVALUATION OF HYPERTENSIVE PATIENTS

DR. V. SIVA SUBRAMANIYAN,

DEPT. OF NUCLEAR MEDICINE,

SSSIHMS, PRASHANTHIGRAM.

A I M S

I N C I D E N C E O F R.A.S

U T I L I T Y OF CAPTOPRIL

E F F E C T O F C A P T O P R I L O N H Y P E R T E N S I V E S

PATHOPHYSIOLOGY OF R.V.H

I N D I C A T I O N S

Accidental invention.

Majid et al 1983

Marked decreased renal uptake

in a patient taking Captopril.

On discontinuation recovery of

renal function.

D I S C O V E R Y

M E T H O D O L O GY

BETA – BLOCKERS AND ANTIHYPERTENSIVES TO BE STOPPED 48 – 72 HRS. BEFORE THE STUDY BASAL RENOGRAPHY TO BE PERFORMED. CLASSICAL CONVENTIONAL PROCEDURE TO BE FOLLOWED.

Tracer 99 Tc m – DTPA.

Dose : 3-5 mCi

Route : IV injection

Preparation : Proper hydration.

R E N A L S C I N T I G R A P H Y

M E T H O D O L O G Y25 – 50 mg CAPTOPRIL TABLETS TO

BE CRUSHED AND ADMINISTERED

ORALLY ALONG WITH 250 ml OF

WATER. 90min. LATER RENAL

SCINTIGRAPHY IS REPEATED WITH

TWICE THE DOSE OF TC 99 m DTPA

USED FOR BASE LINE.

I N T E R P R E T A T I O N

Image analysis

GFR estimation.

Renographic curve analysis

Captopril response

P O S I T I V E C R I T E R I A

Decrease in % of uptake by > 10%.

Reduction in GFR by > 10%

Worsening of renographic curves

Increased tracer retention

Increased transit time

R E N O G R A M T Y P E S

CAPTOPRIL RESPONSE

SSSIHMS PRASHANTIGRAM__________________________________________________________________

Name: Sudha Sree Purna. A Age / Sex: 37/F Hospital No: 53773/k2 Procedure: Captopril Renography Date: 19/08/02 N.M N0. RD /4658&63/2002 Tracer: Tc-99m DTPA Dose: 10 Mci Route: Intravenous Protocol: Gates Diuretic: Lasix 40 mg i.v Time: F 0 Hydration: plenty of oral fluid Clinical History: ? Renovasular Hypertension. Right Kidney small on Ultra Sound Scan. Renal Scan for functional assessment of the Kidneys. Procedure: After obtaining the Basal study Anti-hypertensives stopped for 2 days. Captopril 50 mg administered orally and after 3 hours Renogram study is repeated. IMAGES

INTERPRETATION K I D N E Y S C O R T E X Site Size Position Visualization Delineation Defect Contour RT. Normal Normal Normal Prompt Fair Nil Smooth LT. Normal Normal Normal Prompt Good Nil Smooth C O L L E C T I N G S Y S T E M U R E T E R Visualisn. Delineation Uptake late fill. Visualisn. Accumulation Insertion RT. Prompt Good Increased Nil Faint Trace Normal LT. Prompt Good Increased Nil Faint Trace Normal R E N O G R A P H I C C U R V E A N A L Y S I S PHASE: Uptake Secretory Excretory Diur.response G.F.R % Function Pre Post Pre Post Pre Post Pre Post Pre Post Pre Post RT. Vertical Verti Blunted Blunt. Step PlateauType I TypeIII 36 ml 32 ml 46 % 43 % LT. Vertical Verti Slope Slope Step Step Type I Type I 42 ml 43 ml 54 % 57 % TOTAL GFR Pre 78 Post 75 ml / min IMPRESSION: The Post Captopril Study reveals evidence of Decrease in the Rt. Kidney GFR with worsening of Curve pattern indicating the High Probabiliy of Rt. Renal Artery Stenosis. DR.V.SIVASUBRAMANIYAN, Consultant Nuclear Medicine Physician ___________________________________________________________________________________

CAPTOPRIL SERIES

Male : 16-68 yrs ; 36.4 +- 13.6 51

Female : 15-50 yrs ; 34.5 +- 8.9 17

Total 68

R E S U L T S

Positive : 11 / 68 16%

Negative : 57 / 68 84%

N E G A T I V E G R O U P

Males Females

Pre-capto 61 +- 25 ml/min

66 +- 28 ml/min

Post-capto 75 +- 29 ml/min

82 +- 30 ml/min

C O N T R A I N D I C A T I O N S

B I L A T E R A L R.A.S

DRUG STOPPAGE NOT POSSIBLE

IMPENDING RENAL FAILURE

Recent invention by

Imanishi et al. 1991

Substitute to Captopril.

A S P R I N R E N O G R A P H Y

P R O C E D U R E

Asprin - 20 mg / kg 130 mg

Oral administration

Renal scintigraphy one hour later.

P A T H O P H Y S I O L O G Y

Prostaglandin

Vasodilatation

Increases glomerular blood flow

Asprin blocks prostaglandin

Decrease in glomerular blood flow.

A D V A N T A G E S

No stopping of ACEI / Beta blockers.

No threat of HYPOTENSION.

No hazard of renal shutdown.

DISADVANTAGES

Positive in 57 % only.

Sub-groups specificity.

Selective insensitivity.

F L O W C H A R T

High risk hypertensive

Color duplex doppler sonography

Renal artery stenosis

Positive Equivocal Negative

Drug stoppage

Possible Not possible

PTRA Captopril Asprin Exr. renogram

C O N C L U S I O N

Difficult situations.

Definitive role.

Decision making.