How useful is paracetamol absorption as a marker of gastric emptying? A systematic literature study

Functional dyspepsia is a common disorder in primary care and gastroenterol ogy units; however. the pathophysiology is poorly understood. Delayed gastr ic emptying is present in nearly 40% of patients. We evaluated the validity of the paracetamol absorption test in comparison with scintigraphy for gas tric emptying assessment. Studies comparing scintigraphy with paracetamol a bsorption were selected through a structured Medline search. A correlation coefficient between scintigraphy and paracetamol absorption over 0.6 was co nsidered good, between 0.45 and 0.6 intermediate, and below 0.45 poor. Feas ibility was assessed by studying the administration of paracetamol, frequen cy of blood sampling, duration of the test period, and parameters used in t he analysis. Thirteen studies were identified, eight (127 subjects) found a good correlation between scintigraphy and paracetamol absorption, two stud ies (28 subjects) found a moderate correlation, and three (25 subjects) fou nd no correlation. Parameters used were area under the curve (N = 9), fixed -time concentrations (N = 6), concentration-max (N = 4) and time-to-concent ration-max (N = 5). Repetitive blood samples ranged from 6 to 20 samples. T he durations were 1.5-8 h. In conclusion, the paracetamol absorption techni que generally correlates well to scintigraphy of liquid phase gastric empty ing. The execution and outcome parameters however need further standardizat ion to optimize its' value for clinical use and research purposes.