An evaluation of a duodenal perfusion technique in human studies

A retrospective evaluation was carried out on the standard duodenal perfusion technique in human subjects. Polyethylene glycol (PEG 4000), non-labelled or labelled with 14C, and phenol red were used as duodenal and gastric recovery markers, respectively. The evaluation was limited to the 2-h equilibration period in each study. The studies were carried out on the subjects sitting in an armchair. Multi-perforated wide-bore aspiration tubes accompanied with air ventiles were used for duodenal and gastric aspiration. High perfusion flow rates (less than or equal to 13.5 ml min-1) and a long perfusion segment (15-20 cm) were applied in the duodenum and the collection periods were kept short. An efficient gastric and duodenal aspiration was obtained in most studies with a limited gastro-duodenal and duodeno-gastric flux. On average, the fluctuations in concentration of the duodenal marker (PEG 4000) ('steady state'), expressed as a coefficient of variation (CV), were 13.1 +/- 1.0% (SEM, n = 66). Correlation analysis suggested that the 'steady state' conditions in the duodenum were improved by an efficient gastric and duodenal aspiration and a high perfusion flow rate. This was supported by an inverse correlation found between the magnitude of the gastro-duodenal flux and the marker's fluctuations, the efficiency of the gastric aspiration and the magnitude of the gastro-duodenal flux, and the efficiency of the duodenal aspiration and the magnitude of the duodeno-gastric flux. A high correlation was found between the two duodenal perfusion markers used, PEG 4000 and 14C PEG 4000.