Relative overdose usually occurred in unstable patients who received doses within the usual clinical range. Most of the absolute overdoses occurred as the result of artificial hyperventilation with high doses of inhalational agents, and some were due to unfamiliarity with a new piece of equipment. More than 50 percent of human error is attributed to judgemental error, and has been identified as frequently occurring when the anesthetist is in a hurry and circumvents basic practices and procedures, or when a decision must be made in an emergency. A problem oriented approach to anesthesia will decrease the incidence of complications occurring during and after anesthesia. History of hypothermia, prolonged recovery, unusual reaction, warrants a change in anesthetic drugs and special management.
Pregnancy decreases the anesthetic drug dose requirement.
Hypoxemia and hypotension are more likely to develop during anesthesia in a pregnant female. Anesthesia may result in abortion, despite maintenance of maternal oxygenation and adequate arterial pressure during anesthesia. Evaluation of systems - Temperature, pulse, and respiratory rate, auscultation of heart and lungs, to identify abnormalities. Pathologic abnormalities should be considered, for example, dogs with a fractured jaw, tracheal collapse or cervical mass may be difficult to intubate the trachea or to provide an adequate airway. Every patient which has been in a traumatic accident has thoracic radiographs taken to identify pulmonary contusions, pneumothorax, or ruptured diaphragm.