Studies of gastric emptying in man
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Date
1980Author
Heading, Robert Campbell
Metadata
Abstract
Measurements of gastric emptying in man have "been made 'by
scintigraphic methods "based on a rectilinear scanner or gamma camera.
Xn. the initial studies with a scanner. indium-113m DTPA was evaluated
as a possible radionuclide marker for a test meal and was found to be
satisfactory. Tecluietium~99-1t DTPA was subsequently assessed in
similar studies with a gamma camera. It also proved satisfactory,
although it differed from the indium compound in being substantially
adsorbed to the solid component of a mixed solid and liquid meal. To
establish the reproducibility of the gamma camera method, repeated
measurements were carried out and in studies with saline test meals,
comparison was made with measurements based on aspiration of gastric
contents. Recognition of the marked differences between gastric emptying of
solids and liquids led to the development and validation of a double
isotope method for simultaneous study of solid and liquid components of
a test meal. This method was then applied to the study of patients who
had undergone gastric surgery in an attempt to learn more about the
emptying abnormalities consequent upon gastric surgery. Studies were
also undertaken in diabetic patients with suspected gastric stasis due
to autonomic neuropathy. The effects of metoclopramide therapy for
such patients were examined. Studies of the histamine E^ receptor antagonists, inetiamide and
eimetidino were undertaken to determine whether they had any effect on
gastric emptying. No clinically significant effect was detected.
Gastric emptying was found to be a major regulator of the rate of
absorption of orally administered paracetamol. Pharmacological modification of gastric emptying, namely acceleration "by metoclopramide
and inhibition by propantheline or by narcotic analgesics was associated
with corresponding changes in paracetamol absorption. The absorption
of orally administered paracetamol was also delayed by the gel fibres
pectin and guar, which delay gastric emptying. Scintigraphic measurements of gastric emptying are not free from
experimental error. Measurement of the errors due to count attenuation
by tissues demonstrated the superiority of bilateral detection over
unilateral detection, especially if relatively low energy gamma emitting
radionuclides are being used. The errors associated with unilateral
(anterior) detection of indium-113m and technetium-99m were determined
in studies with a rectilinear scanner and with a gamma camera.