Pitfalls in gastrointestinal permeability measurement in ICU patients

Excerpt

Sir: It is hypothesized that increased intestinal permeability can induce or enhance septic complications in intensive care patients by facilitating bacterial translocation. A reliable and safe detection method would aid in identifying patients with increased intestinal permeability. Intestinal permeability has frequently been measured by tests based on the differential sugar absorption principle. In these tests the ratio of urinary recovery after orally administration of a small permeant sugar probe and large sugar probe, impermeant in the uncompromised intestine, is used as an indication of intestinal permeability [1]. The principle of these tests is that premucosal factors (i.e., gastric retention) and postmucosal factors (i.e., metabolism and renal function) are excluded because these should affect both probes similarly.Therefore only mucosal factors (i.e., intestinal permeability) is indicated. The most commonly used test is the lactulose mannitol test (LMT). Oudemans-van Straaten et al. [2] identified confounding factors when performing the LMT in ICU patients. Their study was conducted in severely ill patients with multiple organ failure. The LMT could still be applicable in patients with milder disease. …