[The principle of "balanced anesthesia" in high risk canine patients]

The concept of balanced anaesthesia aims at an anaesthetic method for high risk patients by combination of different anaesthetic drugs. The anaesthetics and muscle-relaxants have to work in a way as to potentiate their effects and to reduce the side effects as well as the applied dosage. With this sensible regime the circulation and the metabolic energy should be less burdened. For the introduction of balanced anaesthesia, a combination of benzodiazepines (relaxing and sedative), morphine (analgetic and sedative) and quickly metabolizing hypnotics of the imidazol group (hypnotic and relaxing) is used. A fentanyl-drip-infusion continues and deepens the analgesia. After endotracheal intubation with the help of the carrier-gas nitrous oxide (weakly analgetic) and oxygen (2:1) a low concentration of volatile inhalation anaesthetics (weakly hypnotic) is added. Under artificial respiration low doses of competitive antidepolarizing neuromuscular blockers help to potentiate and reduce drug amounts of other anaesthetics especially of that for inhalation. At the end of balanced anaesthesia an antagonization of benzodiazepines, morphines and competitive neuromuscular blockers is recommended for emergency situations only because of possibly occurring changes of cardiovascular parameters.