The study of behavior changes in growing rats under the conditions of halothane anesthesia and premedication with midazolam

Abstract

Background: Cleft of lip and palate is widespread pathology of development. These malformations are repaired with surgery. Inhalation anesthetics, for example halothane, are widely used in pediatric orthognatic surgery, causes side effects. For preventing these complications benzodiazepines (e.g midazolam) are used, but based on last literature sources midazolam may cause long- lasted negative effects, such as high excitation and aggression. At same time, according to the literature, midazolam, which is used in sedation for infants, may have far-reaching adverse effects. For example, initiation of apoptosis in the developing brain, respiratory obstruction and other. The reverse data is obtained from adult white rats. It is determined that midazolam premedication does not react on behavioral characteristics and adaptation ability of experimental animals and reduces the halothane negative impact⁹. Relatively less is studied about far-reaching adverse effects of midazolam in growing organisms.

Aim of research: The effect of midazolam premedication (single injection) on behavior changes of growing rats under the conditions of halothane anesthesia after 1 week from the sham operation.

Methods: Open field test was used to assess behavior parameters and emotions in control and both test groups. We evaluated behavior changes in rats a week after the operation during 5 days. Each animal was explored during 5 minutes every day. There were registered following parameters: Vertical activity, sum of inner, external and center squares, time of staying in the center of the field, groomings, the grooming duration, defecation.

Results: It is shown that midazolam injections did not cause any negative effects on the growing rats’ behavior parameters. The adaptation to environment has been revealed in all three groups a day after. Similar results were shown in the third and fourth days. The high level research activity has been determined in control and third groups, in comparison with halothane group. This fact is related to adaptation to environment and it proves decreasing of tension and fear level. The adaptation to environment and high space orientation of growing rats in third group has to be caused by midazolam premedication.

Conclusions: The reason for weak adaptation to environment after halothane anesthesia compared to intact animals may be the reducing of dendrite growth by halothane in growing animals and thus the inhibition of brain development. The fact that these effects are not revealed after midazolam premedication allow us to think that reducing the anxiety activity of animals after midazolam premedication provides to avoid the inhibition of dendrite growth and brain development. On the bases of our results it is established that a week after operation in growing rats under the halothane anesthesia midazolam premedication (single injection) doesn’t cause any negative influence on behavior parameters of growing animals.