EFFECT OF ERYTHROMYCIN ON GASTRIC-MOTILITY IN MECHANICALLY VENTILATEDCRITICALLY ILL PATIENTS - A DOUBLE-BLIND, RANDOMIZED, PLACEBO-CONTROLLED STUDY

Objective: To document the action of erythromycin on gastric emptying and motility in mechanically ventilated patients. Design: Crossover, d ouble-blind, randomized, placebo-controlled study. Setting: General in tensive care unit in a university hospital. Patients: Ten patients, me chanically ventilated, in a stable hemodynamic condition. Intervention s: Erythromycin (200 mg iv over 30 mins) and placebo were infused at m idmorning, on two consecutive days, in a random order. Pressure change s in the gastric antrum were recorded by means of a multilumen manomet ric tube (perfused catheter technique) over a period of 300 mins, begi nning with the institution of the erythromycin or placebo infusion. Ga stric emptying was simultaneously assessed by the kinetics of the abso rption of acetaminophen delivered into the stomach (1 g with 20 mL of water) immediately before the infusion. Measurements and Main Results: Motility was quantified by determining the number of contractions, th e amplitude of contractions, and the Motility Index (Motility Index = natural logarithm [sum of amplitude x number of contractions] + 1). Co mparison between placebo and erythromycin was made for the first hour after the infusion and for the whole recording session. The maximal ac etaminophen concentration, the time to reach the peak acetaminophen co ncentration, and the area under the concentration-time curve at 60 min s were obtained from serial determinations of plasma acetaminophen con centrations. Compared with placebo, the mean number of contractions (1 04 +/- 34 vs. 5 +/- 8; p = .003), the mean amplitude of contractions ( 52 +/- 16 vs. 20 +/- 17 mm Hg; p = .005), and the Motility Index (13.0 6 +/- 0.95 vs. 4.45 +/- 3.54; p = .004) were significantly increased d uring the first hour after erythromycin infusion compared with placebo . Number of contractions (p = .017) and Motility Index (p < .001) afte r erythromycin infusion remained significantly higher when values thro ughout the whole recording session were considered. The following data were noted after erythromycin was infused: a) the time to reach the p eak acetaminophen concentration was shorter (32 +/- 8 vs. 171 +/- 93 m ins; p = .007); b) the maximal acetaminophen concentration was higher (22.09 +/- 6.23 vs. 5.38 +/- 3.80 mu g/mL; p = .007); and c) the area under the concentration-time curve at 60 mins increased markedly (730 +/- 269 vs. 72 +/- 42 mu g/min/mL; p = .002) as compared with placebo. Conclusion: In mechanically ventilated patients, intravenous erythrom ycin (200 mg over 30 mins) increases indices of antral motility and ac celerates gastric emptying as assessed by the kinetics of acetaminophe n absorption.