Abstracts
1997 Digestive Disease Week

Ambulatory measurement of gastric emptying is a sensitive technique in detecting abnormal gastric emptying patterns.

MP Ritter, M Fein, TR DeMeester, PF Crookes, JH Peters, M Gadenstatter, JA Hagen, CG Bremner. Department of Surgery, University of Southern California, Los Angeles, CA.

A new intragastric probe that allows measurement of gastric emptying in an ambulatory mode is now available. The aim of the present study was to compare the use of this probe with conventional gamma camera scanning in patients with foregut symptoms and to compare the sensitivity of gastric emptying studies in a supine position against measurements in a sitting and standing/walking posture.

A cadmium telluride gamma detector probe (Synectics Medical) was placed transnasally 5cm below the lower esophageal sphincter in 30 normal volunteers and 55 consecutive patients with foregut symptoms. Three identical test meals each consisting of one scrambled egg labeled with 1 mCi Tc 99m sulfur colloid were given at 8 am, 12 noon and 4pm. Gastric emptying was measured for three hours after each meal. The patient remained sitting after the 8 am meal, semireclining after the noon meal and standing or walking after the 4pm meal. Simultaneous gammacamera scanning was performed for two hours following the noon meal and the percentage radioactivity retained within the stomach after 120 min was compared between the two techniques. Delayed gastric emptying was diagnosed when the radioactivity retained within the stomach exceeded the 95th percentile of normals during three or more consecutive ten minute intervals starting 90 minutes after the onset of measurement. The presence of gastric symptoms (nausea, vomiting, fullness/early satiety, bloating, left upper quadrant pain) was correlated with the test results in the semireclining position and the results in the sitting (ambulatory) and standing-walking (ambulatory) postures.

The gamma camera and the intragastric probe measurements in the semireclining position were strongly correlated (r=0.79; p<0.001). Of the 55 patients 33 (60%) presented with gastric symptoms. In this group delayed gastric emptying was detected more frequently with the repetitive measurements in the sitting and standing/walking postures, when compared to a single measurement in the semireclining position (table)

  Measurement                      Delayed gastric emptying
                      No gastric symptoms(N=22)   Gastric symptoms(N=33)
Gamma-camera (supine)          0                         18%
 Probe (supine)                9%                        21%
 Probe (ambulatory)            5%                        42%

The ambulatory equipment used with the intragastric probe facilitates repetitive measurements of gastric emptying in different postures, which are more sensitive in detecting delayed gastric emptying in patients with gastric symptoms than a single measurements in the semireclining position.