Use of photoplethysmography to determine gastrointestinal perfusion pressure: an experimental canine model.

<i>Objectives:</i> To develop an experimental model to assess the parietal perfusion pressure (PPP) of the digestive tract using photoplethysmography. <i>Materials and Methods:</i> Twenty-two mongrel dogs were used. Progressive external compression was applied to the intestinal wall and the PPP was assessed with photoplethysmography. The study group was divided into two groups. In group 1 PPP was measured at the levels of the stomach, duodenum, jejunum and transverse colon. In group 2 PPP was measured after temporary occlusion of the truncal and marginal circulation of the jejunum to provide further variables. <i>Results:</i> The PPP decreased significant…