Anesthesia and Analgesia in Laboratory Rats: Combinations of Drugs Applied, their Effects on Animals, Optimal Solutions for Reducing Side Effects

Currently, a great number of research studies, including those involving surgical interventions, is carried out on experimental models demonstrating pathological processes in rats. In this regard, there is a need for effective and time-controlled techniques of anesthesia and analgesia applicable to a selected group of animals, with subsequent assessment of the anatomical and physiological effects of the selected drug combination. The available options for general anesthesia are distributed in a wide range by the nature of their effect, the duration of action, the process of postoperative recovery within the framework of specific experimental models. This provides relevant search for the most effective and safe drugs. The article discusses the principles of anesthesia in experimental animals (rats), and the most common drugs and their combinations, including isoflurane, a combination of ketamine-xylazine and other ketamine combinations; the effect of a combination of medetomidine, midazolam and butorphanol, the effect of sodium phenobarbital and the use of chloralose are described. All the above drugs are used for anesthesia and analgesia during surgical interventions on experimental models. Notably, besides anesthetic and analgesic effects on the animal's body, they also cause changes in a number of physiological functions, including the work of the heart, brain and respiratory organs, thus, being key factors in the deterioration of the recovery process of animals in the postoperative period or causing animals’ death during the experiment.