The risks and complications of sedation are the same as for general anesthesia. Thus, unconscious patients are essentially under general anesthesia. Most sedative agents require larger doses comparatively than anesthetic agents and the overall duration is much longer. Sedated patients should be monitored just as closely as anesthetized patients, but too often are not. When serious problems occur during sedation it is invariably due to a lack of monitoring, which leads to the next point.
Monitoring is the key to safety.
One cannot alter an anesthetic agent or resuscitate the patient unless one knows what is happening to the patient, veterinary or human. Without electronic monitors one is left with a finger on the pulse, the sound of the heart and lungs, and the color of the blood. These are still pretty reliable for the practiced anesthetist. The anesthetist, however, must know what's going on with the patient. In the veterinary office, the surgeon may be both the anesthetist and the operator.