ESPN 51th Annual Meeting

ESPN 2018


 
SINGLE INTRAVENOUS ACCESS FOR MEASUREMENT OF GLOMERULAR FILTRATION RATE IN CHILDREN AFTER MARKER INJECTION
THEA TISLEVOLL EIDE 1 ATLE BRUN 1 BRACKMAN DAMIEN 2 BJøRN BOLANN 1 EINAR SVARSTAD 2 CAMILLA TøNDEL 2

1- UNIVERSITY OF BERGEN
2- HAUKELAND UNIVERSITY HOSPITAL
 
Introduction:

Measurement of glomerular filtration rate in children by injection of a marker and blood sampling from the contralateral arm is widely used in clinical practice. The purpose of our study was to determine if the cannula that is used for injection of iohexol can also be used for blood drawings to measure the iohexol plasma concentration.

Material and methods:

In 32 children with chronic kidney disease, with a median age of 10.5 (range 6-17) years, venous blood samples were collected from the injection cannula and another cannula in the contralateral arm. After injection of iohexol, the intravenous access was flushed with 15 ml saline in the main entrance, 5 ml in the upper access, and thereafter 10 ml in the main entrance. Venous blood samples were collected at 2, 3, 3.5 and 4 hours after iohexol injection, each time with preceeding draws of 0.5 ml discarded blood. For each time point, the iohexol plasma concentrations in the samples from the 2 cannulas were compared with each other. At each time point saline was flushed in the intravenous access after blood sampling.

Results:

The first blood sample taken after injection, drawn after 2 hours, had mean bias 5.64, limits of agreement -19.82 to 31.10. Iohexol concentrations determined in samples drawn after 3, 3.5 and 4 hours i.e. after additional flushing of the injection cannula as well as 2-4 draws of discarded blood samples, showed mean bias of 1.72, 0.65 and 0.92, limits of agreement -6.39 to 9.83, -5.82 to 7.12 and -5.45 to 7.29, respectively.

Conclusions:

Iohexol concentrations from blood samples drawn after 2 hours, i.e. after substantial flushing with saline, but only one discarded blood sample, showed high risk of contamination of injected marker. Samples drawn after several discarded blood draws showed relatively good agreement with samples from the contralateral arm.