Effects of intravenous ketamine on gastrointestinal motility in the dog.

OBJECTIVE

The purpose of this trial was to clarify the effects of intravenous ketamine at anaesthetic and sub-anaesthetic dosages on gastrointestinal motility.

DESIGN

20 beagles (group 1: 3 mg/ketamine/kg/h, n = 10; group 2: 30 mg ketamine/kg/h, n = 10), were investigated. Gastric emptying (nuclide gastric emptying studies, liquid and semi-solid test meal), intestinal transit time (Hydrogen breath test with lactulose) and intestinal motor function (perfusion manometry with 8 measuring ports) were determined. As a control condition, the tests were performed on all dogs in the two groups during infusion of physiological saline solution.

RESULTS

No significant differences in the motility patterns were present between 3 mg ketamine/kg/h and the control condition. For group 2, a moderately significant (p < 0.05) increase in the interdigestive motility index was observed for 30 mg ketamine/kg/h. However, this did not change the transit criteria. There was no significant difference between ketamine and control condition tests with regard to cycle and phase lengths or the propagation rate of the activity front.

CONCLUSIONS

We conclude that ketamine provokes no basic changes in gastrointestinal motility, at either sub-anaesthetic doses. It can therefore be used to advantage in the continuous postoperative analgesia of intensive care patients, where repeated interventions are necessary and no cardiopulmonary contraindications are present.