Neurourology and Urodynamics 13:619622 (1994)

Diuresis Renography: I.S.D.U. Proposal for Standardisation Pat O’Reilly, Bo Coolsaet, and Steve Koff

Department of Urology, Stepping Hill Hospital, Stockport, England (I? 0.); Department of Urology, Klina Hospital, Kapellen, Belgium (B. C.); Department of Pediatric Urology, Children k Hospital, Columbus, Ohio (S. K.)

INTRODUCTION

Standardisation of technique allows a comparison of results of procedures be- tween different centres. Many different techniques for the performance of diuresis renography have been reported over the years.

The comments below represent proposals of protocols as they have been dis- cussed at the I.S.D.U. The chairman’s group has published a comprehensive review article [O’Reilly, 19921.

PRE-EXAMINATION PREPARATION

I . Explain procedure, prcferably before the patient attends. 2. Ensure normal hydration (many patients automatically assume they should

3 . Give 500 ml oral fluid load on arrival in department. 4. Ensure patient empties bladder before examination. 5 . Ascertain diuretic timing F(L) + 20 or F(L) - 15 o r 20. 6. Ascertain catheter requirement.

dehydrate).

POSITION Sitting/Erect

Lying/Supine

I t is absolutely necessary to mention the position. Under normal conditions, transport is effected by active coapting contractions in the ureter, which is loaded with boluses by a delicate active mechanism at the pelviureteric junction (P .U.J . ) . These

Received for publication April 4. 1994; accepted May 6 . 1994.

Addrehs reprint requests t o Pat O’Reilly, Department o f Urology. Stepping Hill Hospital. Stockport SK2 7JE. U.K.

0 1994 Wiley-Liss, Inc.

620 O’Reilly et al.

mechanisms do not function under high diuretic conditions or in dilated systems. Under these conditions, open tube flow takes place. This type of flow is dependent on hydrostatic pressure differences. For general practice, sitting is preferable for the above-mentioned reasons and the patient’s comfort.

RADIOPHARMACEUTICALS

I . 1231-Hippuran 2. 99mTc-MAG3 3. 99mTc-DTPA

FUROSEMIDE - (LASIX*)

1 . Dosage: 0.5 mg per kg (40 mg in adults) 2. Administration: 20 minutes after radiopharmaceutical administration: F (L)

3. 15 or 20 minutes before radiopharmaceutical administration: F (L) - IS or + 20

F ( L ) - 20

In some circumstances (e.g., a very large renal pelvis) some workers have waited 30 or even 40 minutes to ensure adequate filling before giving the diuretic. If this individual variation is desired, it helps standardisation if the renogram is labelled F (L) + 30 or F (L) + 40 accordingly.

F (L) + 20 DIURESIS RENOGRAPHY

1 . Ensure that the patient is in a good state of hydration and that there is no

2. Follow the standard renogram procedure [O’Reilly et al., 19861 including

3. Ask the patient to empty hidher bladder. 4. After the radiopharmaceutical has been injected, pictures are taken every

minute to evaluate upper tract morphology. 5 . At 20 minutes into the test, inject furosemide (Lasix@) at a dose of 0.5 mg

per kg body weight. Note the time. Continue with renography until significant elim- ination occurs or until 10-15 minutes after the diuretic was administered. In case the patient cannot hold urine, let h idher freely pass urine in a urinal.

clinical reason why diuresis should not be induced.

pre-examination preparation above.

6. Warn the patient that the effect of diuresis will last for an hour or two.

F (1) - 15 DIURESIS RENOGRAPHY

1 . Ensure that the patient is in a good state of hydration and that there is no

2. Ask the patient to empty hidher bladder. 3 . Insert a butterfly needle into a suitable vein. Inject furosemide (Lasix@) at a

clinical reason why diuresis should not be induced.

dose 0.5 mg per kg body weight. Wait IS minutes before starting step 4.

Diuresis Renography 621

4. Inject the radiopharmaceutical as for a routine renogram. 5. Warn the patient that the effect of the diuresis will last for an hour or two.

COMBINED F (L) - 15 AND DlURESlS RENOGRAPHY

This method may only be used if most of the activity has been excreted from the kidneys by the end of the routine F (L) + 20 renogram.

1 . Check the patient is in a good state of hydration and that there are no clinical

2. Perform a standard F (L) + 20 diuresis renogram. 3 . I f 15 minutes after the injection of furosemide most of the activity has left

the kidneys, inject a further dose of radiopharmaceutical. A second dose equal to the first dose should be sufficient. Thus an F (L) - 15 study is initiated.

4. Continue the renogram as from step 5 in the F (L) - 15 diuresis renography protocol.

reasons why diuresis should not be induced.

ROLE OF INDWELLING CATHETER

A full or filling bladder may affect upper tract emptying in some cases. This interactive effect of the bladder on renal emptying may be one of the major aims of the assessment. I t is therefore of crucial importance to start the renography after the patient has voided, and to assess upper tract emptying under fast filling bladder conditions.

Most patients feel the urge to void after furosemide (Lasix) injection. I t is particularly important to allow the patient to void and continue data collection. This will reflect urodynamic changes in the upper tract consequent on lower tract emptying.

In certain groups of patients, bladder emptying will be impossible. Patients with significant residual urine, neuropathic bladders, or low compliant bladders will there- fore require a (second) renogram with an indwelling catheter in order to be able to predict potential outcome of treatment of lower tract dysfunction. In others, as in vesico-ureteric reflux, precise upper tract emptying can obviously only be assessed with indwelling catheter.

DlURESlS RENOGRAPHY-INTERPRETATION

Normal response before diuresis: In some wide systems upper tract emptying is normal under normal diuretic conditions. Theoretically, the possibility exists that the system could decompensate at high diuretic flow rates. This is very rare.

OTHER RESPONSES

Interpretation of results has to be performed with great care for two major reasons.

1 . Upper tract transport is active at flow rates below 9 ml/min. At higher flow rates or when coapting contractions are impossible for other reasons, transport is

622 O’Reilly et al.

passive. There is n o correlation between active and passive transport. Diuresis renog- raphy only assesses passive transport.

2. The evacuation curve is multifactorial. It depends o n several factors. only one of them is resistance to passive outflow.

For these reasons, renogram parameters cannot be used as a Gold Standard of obstruction, whatever that term might mean. Furthermore, if single kidney glomer- ular filtration rate (SKGFR) = 14 ml/min. the result must be scrutinised. Renal parenchymal transittimes may be high and flow increase may be too small. Huge capacity systems (e.g., Prune Belly) also provide unreliable results.

Under conditions of acceptable renal function ( 16 ml/min), (well hydration, mild dilatation) curves can bc labeled qualitatively as:

1 . Positive or obstructive when curves after injection of Lasix (L + 20 or L- 15) remain horizontal o r increasing.

2. Negative o r unobstructive when curves after Lasix injection are normal or return promptly toward normal levels.

3 . Equivocal when the shape of the curve is in between (a) and (b); when the response to Lasix is fast but incomplete; or when there is an initial decrease followed by a second rise. Mathematical descriptions of the evacuation curves do not make sense because significant qualitative changes are seen depending on the method used. A negative F (L) + 20 may be converted to a positive curve by using the F (L) - 15 technique and vice versa.

THE ROLE OF RENAL FUNCTION ASSESSMENT

0 To establish baseline split renal function. 0 To investigate post operative improvement in split function 0 To provide data on single kidney GFR for interpretation. 0 To assist in conservative management of equivocal cases.

Note that there is no significant difference between split function values in F (L) + 20 and F (L) - 15 diuresis renograms, so the two techniques are interchangeable and comparable in terms of renal function determination.

Note that renal function determination is dependent on the position of the kidney. Nephroptosis may erroneously reduce the split renal function.

REFERENCES

O‘Reilly PH ( 1992): Diuresis renography: Recent advances and recommended protocols. Br J Urol

O’Reilly PH, Shields RA, Testa HJ (eds) (1986): “Nuclear Medicine in Urology and Nephrology.” 2nd 69:l 13-120.

ed. London: Ihtterworths. pp 7X-80.