Correlation between urine ketones (acetoacetate) and capillary blood ketones (3-beta-hydroxybutyrate) in hyperglycaemic patients.
OBJECTIVE
To facilitate the transition from urine ketones (acetoacetate) to capillary blood ketones (3-beta-hydroxybutyrate), we studied the correlation between these two tests.


METHODS
Retrospective study of all patients with blood glucose greater than or equal to 2.5 g/l on arrival in the Emergency Department. We studied the correlation between urine ketones (Clinitek 50, Bayer) and capillary blood ketones (Optium, Abbott). We then compared the relative risks (RR) of ketoacidosis and hospitalization associated with each of these tests.


RESULTS
In 33 months, 529 adult patients with both urine and blood testing for ketones were enrolled (ketoacidosis 8%, admission rate 49%). Urine ketones scored as +, ++ and +++ corresponded to median capillary blood ketone levels of 0.5 mmol/l (IQR: 0.1-0.9), 0.7 mmol/l (IQR: 0.2-1.8) and 3 mmol/l (IQR: 1.4-5.2), respectively. RRs of ketoacidosis or hospitalization associated with blood ketones greater than or equal to 3 mmol/l were higher than those associated with +++ urine ketones: 74 (95% confidence interval [CI]: 48-88) and 2.9 (95% CI: 2.5-3) versus 31 (95% CI: 18-45) and 2 (95% CI: 1.7-2.1), respectively.


CONCLUSIONS
In hyperglycaemic patients in the Emergency Department, a good correlation was observed between urine ketones and capillary blood ketones for low values, but a poor correlation was observed for high values. Either test can therefore be used to exclude ketosis, but the capillary blood ketones test is more accurate to confirm ketoacidosis.
Taboulet
P
P
Emergency department, hôpital Saint-Louis (APHP), université Paris-VII, 1 avenue Claude-Vellefaux, 75475 Paris cedex 10, France. pierre.taboulet@sls.aphp.fr
Deconinck
N
N
Thurel
A
A
Haas
L
L
Manamani
J
J
Porcher
R
R
Schmit
C
C
Fontaine
J-P
JP
Gautier
J-F
JF
D020155:3-Hydroxybutyric Acid / Q000097:blood*; D000090:Acetoacetates / Q000652:urine*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D006943:Hyperglycemia / Q000097:blood* / Q000652:urine; D007659:Ketones / Q000097:blood / Q000652:urine; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012189:Retrospective Studies
D000090:Acetoacetates; D007659:Ketones; C016635:acetoacetic acid; D020155:3-Hydroxybutyric Acid