ABSTRACTS PRESENTADOS AL 11th INTERNATIONAL SYMPOSIUM "RADIONUCLIDES IN NEPHRO-UROLOGY", REALIZADO EN MONTEREY, CALIFORNIA, 13-17 MAYO 2001.

Eysteinn Petursson.
Landspitali-University Hospital, Reykjavfk, Iceland.

clearance is conventionally measured by drawing 3 blood samples after 2, 3 and 4 hrs from the injection. Single sample clearance methods have also been advocated. When clearance is suspected to be low it has been recommended that a late blood sample be drawn, even as late as 24 hrs post injection (for clearance < 15 ml/min).

During the interval June 1999 to October 2000 we have done 93 evaluations (79 pts) of - clearance by drawing 5 blood samples at 2,,3,4,5 and 24 hrs post injection and compared the result obtained from all five samples (1-5) to those obtained from sample (1-3), (1-4), (2-4), and (3-5) respectively. A paired t-test was used for the comparison.

Results: 20 measurements on 18 pts gave clearance values between 2.6 and 15 ml/min/1.73m2 by the 1-3 sample method (1-3). There was good correlation between all methods. The mean values declined slightly from method (1-3), which gave 10.2, through (1-4), (2-4), (1-5) and (3-5), which gave 9.1 ml/min/1.73m2 . There was significant differences at the 5% level between method (1-3) vs (1-5), (1-3)vs (3-5), (1-4) vs (1-5), (1-5) vs (3-5) and (1-4) vs (3.5).

Conclusions: The results could indicate that 1) when -clearance is evaluated the 1st blood sample should be drawn no earlier than 3 hrs post injection. 2) kidney function is diminished during the night.