Lower Esophageal Sphincter Clinical Trial
Official title:
The Effect of Alfentanil on the Lower Esophageal Sphincter During Anesthesia Induction - a Study in Volunteers
This study evaluates the effects of adding an opioid (alfentanil) during anesthesia
induction with respect to the barrierpressure in the esophagogastric junction.
The secondary aim was to investigate whether the effect of cricoid pressure influences the
barrierpressure.
During anesthesia induction and tracheal intubation one major concern is to avoid passive
regurgitation of gastric content and aspiration.
The lower esophageal sphincter is a muscle located at the distal end of the esophagus. It
plays an important role in creating a barrier between the stomach and the esophagus. The
term "barrierpressure" is defined as the pressure difference between the lower esophageal
sphincter pressure and the pressure in the stomach (intragastric pressure).
There are studies showing that opioids given iv/im, in the vein or in the muscle, may
decrease the pressure in the lower esophageal sphincter and hereby increase the risk of
aspiration.
Nevertheless,other studies shows that opioids are still frequently given to patients during
anesthesia induction. This is done in order to prevent the cardiovascular response to (the
painful) intubation which can often be seen as an equally high risk for the patient as the
risk of aspiration.
In light of the above description, the investigators are planning a study in volunteers with
the primary aim of investigating the effects of an opioid (alfentanil) on the pressures in
the lower esophageal sphincter.
Another safety measure taken during anesthesia induction is the so called "cricoid
pressure". This is based on the theory that passive regurgitation of gastric content may be
prevented by occluding the esophagus by pressing on the cricoid cartilage. However, there
are studies indicating that the application of cricoid pressure also may decrease the tonus
of the lower esophageal sphincter.
The secondary aim of the study is to investigate the effect of cricoid pressure application
on the pressure in the lower esophageal sphincter.
Measurements are being done using high-resolution solid-state manometry.
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Allocation: Randomized, Intervention Model: Crossover Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Primary Purpose: Prevention