The Impact of Postoperative Enteral Immunonutrition on Postoperative Complications and Survival in Gastric Cancer Patients - Randomized Clinical Trial

BACKGROUND

Immunomodulating enteral nutrition in the perioperative period may reduce postoperative complications in cancer patients. Little is known if this effect translates to the better survival. The aim of study was to assess the impact of postoperative immunomodulating enteral nutrition on postoperative complications and survival of gastric cancer patients.

METHODS

A group of 98 gastric cancer patients was randomly assigned for postoperative immunomodulating enteral nutrition n = 44 (Reconvan, Fresenius Kabi, Bad Homburg, Germany), or standard enteral nutrition n = 54 (Peptisorb, Nutricia, Schipol, The Netherlands). Postoperative complications, mortality, 6-mo and 1-yr survival were analyzed.

RESULTS

The overall postoperative morbidity did not differ between the groups. The rate of pulmonary complications (excluding pneumonia) was significantly lower in immunomodulation group (0% vs 9.3%, p = 0.044), as well as 60-day mortality (0% vs. 11.1%, p = 0.037). There was no difference in 6-mo and 1-yr survival between the groups.

CONCLUSIONS

Postoperative immunomodulating enteral nutrition may reduce respiratory complications and postoperative mortality in comparison to standard enteral nutrition. Despite this effect, it did not improve 6-mo and 1-yr survival in immunomodulation group. Probably the beneficial effect of immunomodulating enteral nutrition is too weak to be significant in such a number of patients.

Chronic flumazenil (Ro 15-1788) facilitates acquisition and retention of a swim-escape response in rats

Since chronic flumazenil treatment was previously found to stimulate exploratory behavior in rodents, the aim of this study was to test the effect of chronic exposure to flumazenil on acquisition and retention of escape behavior. Adult rats were treated with flumazenil (Ro 15-1788; 4 mg/kg/day in drinking water) for 21 days (experiment 1) and for 17 days (experiment 2). In experiment 1 (a round water tank with one escape rope) conducted 24 h after drug/vehicle withdrawal, the time the animals needed to resolve a swim-escape task was significantly shorter in the drug group, compared to the controls. In the retention trial, 24 h later, the control group matched the performance of the drug group. In experiment 2, a water T-maze was used which was equipped with two ropes, one anchored to the bottom and the other unanchored and therefore was more difficult to climb. On day 14 of flumazenil/vehicle treatment, there were no differences between the groups in the time needed to escape from the maze. However, on day 15 and 16 of drug/vehicle treatment, the drug group made highly significant progress, while the control group showed no improvement of the escape behavior. The possible mechanisms of flumazenil-induced facilitation of escape behavior have been discussed.

Chronic administration of flumazenil (Ro 15-1788) enhances non-appetitive exploratory behavior of rats

The effects of chronic administration of the benzodiazepine receptor antagonist, flumazenil (Ro 15-1788; 4 mg/kg/day for 14 days in drinking water) on the performance of adult rats in the 12-arm radial maze were studied. Relative to controls, the animals treated with flumazenil showed an increase (P less than 0.002) in non-appetitively motived exploratory behavior, so called because it occurred in 88% of instances in non-baited alleys, facing the well-illuminated "enriched environment" of the center of the room, as opposed to the baited alleys, facing the "dull" corner of the room. This behavior emerged between day 5 and 7 of treatment with the drug, it continued to increase over the period of treatment with drug (P less than 0.002), and reached its peak at day 3, after withdrawal of the drug (P less than 0.008; a longer duration was not investigated). The occurrence of non-appetitively motivated exploratory behavior was inversely correlated with the scores for urination/defecation (P less than 0.003) and, therefore, most likely reflected the anxiolytic action of flumazenil. During treatment with drug or vehicle, the control and the drug groups made comparable numbers of "working memory" errors (P = 0.17). However, upon withdrawal of drug and introduction of alley gates (to confine the animal for 10 sec to the center platform, after an alley was explored), the working memory errors of the rats exposed to the drug, remained unchanged (P = 0.35), relative to the preceding three trials, while the performance of the control group was disrupted, as shown by an increase in the numbers of errors (P less than 0.004). At day seven of treatment with drug, the emergence of exploratory behavior was associated with an increased density and/or affinity of benzodiazepine receptors in cortex, hippocampus and brain stem, while three days after withdrawal of drug, when the exploratory behavior reached its peak, there was a reduction in GABA-enhanced binding of [3H]flunitrazepam in the cortex.