Intestinal absorption in patients after cardiac surgery

Objectives: We designed this study to assess intestinal absorption in patie nts with adequate or altered hemodynamic status after cardiac surgery and t o test clinical tolerance to early enteral nutrition. Design: Prospective, descriptive study. Setting: Surgical intensive unit in a university teaching hospital, Patients: Cardiac surgery patients, age 64 +/- 10 yrs (mean +/- so) were su bdivided into two groups according to hemodynamic status: group 1, 16 patie nts with adequate hemodynamic status; group 11, 23 patients with hemodynami c failure. These groups were compared with healthy controls (group iii, n = 6). Interventions: Paracetamol pharmacokinetic study on days 1 and 3 with nasog astric or postpyloric paracetamol administration. Early postpyloric or conv entional gastric nutrition in group II. Measurements and Main Results: Plasma concentrations were measured on days 1 and 3, and area under the curve (AUC) was calculated, Absorption was stro ngly reduced on day 1 in all patients after gastric administration (lower p eak paracetamol and AUG), but normal after postpyloric delivery. Duration o f anesthesia and of circulatory bypass did not affect paracetamol absorptio n. On day 3, AUC was close to normal in case of hemodynamic failure. Peak a bsorption on day 1 was negatively correlated with opiate dose (r(2) = 0.176 , p = .008). Hypocaloric enteral nutrition was well tolerated. Conclusions: The close-to-normal AUG, during low cardiac output, despite lo wer peak paracetamol, shows absorption was not suppressed, only delayed, be cause of decreased pyloric motility, The decrease on day 1 can be attribute d to opiates, known to alter pyloric function and to slow down the intestin al transit.