Intrasubject variability of gastric emptying in the critically ill using a stable isotope breath test.
OBJECTIVE
Isotope breath tests are increasingly used to evaluate the effects of prokinetic drugs on gastric emptying. The aim was to assess intrasubject variability in gastric emptying, when using an isotope breath test in the critically ill.


METHODS
A retrospective analysis of data was undertaken in 12 patients who had gastric emptying measurements on consecutive days using a (13)C-octanoic acid breath test. The gastric emptying coefficient--GEC (a global index for the gastric emptying rate), and the t(50) (calculated time for 50% of meal to empty) were calculated, together with the coefficient of variability for these parameters. Data are mean (SD).


RESULTS
Neither GEC (day 1: 3.3 (0.8) vs. day 2: 3.1 (0.6); P = 0.31) nor t(50) (day 1: 127 (43) min vs. day 2: 141 (48) min; P = 0.46) were significantly different between the two days. Intrasubject variability was less for GEC (15.6%) than for t(50) (31.8%).


CONCLUSIONS
There is only modest intrasubject variability in GEC measurements using the (13)C-octanoic acid breath test in critically ill patients. As such, it may be an acceptable measurement tool to assess the effects of prokinetic drugs in this group.
Deane
Adam M
AM
Intensive Care Unit, Royal Adelaide Hospital, Adelaide, Australia. adam.deane@adelaide.edu.au
Zaknic
Antony V
AV
Summers
Matthew J
MJ
Chapman
Marianne J
MJ
Lange
Kylie
K
Ritz
Mark A
MA
Davidson
Geoff
G
Horowitz
Michael
M
Fraser
Robert J L
RJ
D000293:Adolescent; D000328:Adult; D000368:Aged; D001944:Breath Tests; D002210:Caprylates / Q000032:analysis*; D002247:Carbon Isotopes / Q000032:analysis; D015331:Cohort Studies; D016638:Critical Illness; D004750:Enteral Nutrition; D005260:Female; D005746:Gastric Emptying; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D055815:Young Adult
D002210:Caprylates; D002247:Carbon Isotopes