DUODENAL MOTOR RESPONSE TO CONTINUOUS ENTERAL FEEDING IS IMPAIRED IN MECHANICALLY VENTILATED CRITICALLY ILL PATIENTS

In order to investigate the duodenal motor response to continuous ente ral feeding during critical illness, we recorded the duodenal contract ions of 12 mechanically ventilated critically ill patients during a 4 h fasting period immediately followed by another 4 h period of continu ous (100 kcal/h) nasogastric feeding with a polymeric diet. Duodenal m otility was recorded by manometry (perfused catheter technique) and th e migrating motor complexes (MMC) were identified by their activity fr ont (period of high frequency, regular contractions). The incidence an d the mean duration of activity fronts as well as the mean duration of the MMC (time interval separating two successive activity fronts) rec orded during both periods were compared. The incidence of activity fro nts (fasting: median: 2.5, interquartile range: 5.5; feeding: median: 2, interquartile range: 3.5), their duration (fasting: 6.2 +/- 1.6 min ; feeding: 5.8 +/- 1.6 min), and the mean duration of the MMC (fasting : 50.9 +/- 24.7 min; feeding: 49.1 +/- 20.3 min) were similar during b oth periods. We conclude that in these patients, the fasting pattern o f motility is not interrupted by the continuous nasogastric administra tion of a polymeric diet. Since the activity fronts of the MMCs are hi ghly propulsive, we suggest that their abnormal persistence during fee ding may play a role in the pathophysiology of unexplained diarrhoea i n some critically ill patients.