Metoclopramide improves gastric but not gallbladder emptying in cardiac surgery patients with early intragastric enteral feeding: randomized controlled trial.

Aim: To evaluate the effect of metoclopramide on gastric emptying in coronary artery bypass graft (CABG) surgery patients with early enteral nutrition and to evaluate the effect of metoclopramide on motility of the gallbladder in these patients.

Methods: A prospective, randomized, placebo-controlled, double-blind study of 40 patients treated at cardiosurgical intensive care unit after CABG surgery. The patients were divided into two groups: metoclopramide group (20 patients; age 60-/+9 years; 85% male), and control group (20 patients; age 59-/+8 years; 70% male). In both groups, enteral feeding with isoosmotic enteral formula was initiated by nasogastric tube 18 hours after surgery. After 6 hours, feeding was stopped, and paracetamol solution (1,000 mg) and 10 mg of metoclopramide IV or 2 ml of saline IV were concurrently administered. Blood samples were obtained 15 (t(+15)), 30 (t(+30)), 60 (t(+60)), and 120 (t(+120)) minutes after the administration of paracetamol. Paracetamol absorption was assessed from the plasma paracetamol concentration and the area under the curve (AUC) from 0 to 120 minutes. Sonographic measurement of gallbladder ejection fraction was also performed 15 (t(+15)), 30 (t(+30)), 60 (t(+60)), and 120 (t(+120)) minutes after the administration of paracetamol.

Results: The plasma paracetamol concentrations 15, 30, 60, and 120 minutes after the administration of paracetamol were significantly higher in metoclopramide group than in control group: (t(+15)) 5.4-/+2.7 vs 3.3-/+2.5 (Mann-Whitney U test; P=0.017); (t(+30)) 6.7-/+2.4 vs 3.7-/+2.0 (P=0.006); (t(+60)) 7.7-/+2.5 vs 5.1-/+3.2 (P=0.008); (t(+120)) 8.5-/+2.2 vs 5.2-/+2.8 (P=0.005). The AUC value was 34% larger in the metoclopramide group vs control group (574-/+296 vs 429-/+309; P=0.027). There were no significant differences in gallbladder ejection fraction between groups (group metoclopramide vs control group: (t(0)-t(+15)) -2% vs -2%; (t(+15)-t(+30)) 1% vs 4%; (t(+30)-t(+60)) 0% vs -1%; (t(+60)-t(+120)) 1% vs 3%; P=NS).

Conclusions: In CABG surgery patients with early enteral feeding, a single dose of intravenous metoclopramide effectively improves gastric emptying, but does not have any prokinetic effect on gallbladder motility.