Gastric Emptying and Small Intestinal Transit Time in Preterm Infants: a Scintigraphic Method

Objectives: Practical methods to determine gastric emptying (GE) and small intestinal transit time in preterm infants are required. The aim of this study was to develop a scintigraphic method to determine GE and small intestinal transit time in preterm infants which produce minimal radiation exposure and physical disturbance in these infants.

Methods: Ten premature infants were studied. Median (and range) for gestational age was 28.9 (26-33) weeks, postnatal age was 19 (6-37) days, birth weight was 1194 (687-2300) grams and feeding volume was 173 (6-205) mL/kg/day. Nine of the patients were on nasal continuous positive airway pressure; one patient was on mechanical ventilation. A dose (0.2-0.4 MBq) of 99mTc-DTPA (0.5 mL) was given at the end of a meal administered by naso-gastric tube. Static images were obtained with a mobile gamma camera during the next 9 to 12 hours. The radiation dose was at most 0.30 mSv. Regions of interest (ROIs) were drawn around the stomach and the cecum. Time-activity curves were generated. Gastric emptying half-time (T(1/2)GE) was calculated. Residual gastric activity after 1 hour (R(1h)) and after 2 hours (R(2h)) was determined. Orocecal transit time was defined as the time until significant increase in activity was detected in the cecal ROI.

Results: Images showed gastric emptying in all cases. Median (range) half time was 1.0 (0.5-3.0) h. R(1h) was 37.5% (19% to 100%), R(2h) was 23% (6% to 61%). In one patient the tracer did not reach the cecum within 12 hours. In the remaining nine patients orocecal transit time was 3.1 (1.3-6.1) h.

Conclusions: We present a new scintigraphic method to determine GE and orocecal transit time. It appears safe and practicable as a research tool in preterm infants.