Preoperative procedures associated with anesthesia

perioperative complications and deaths are frequently caused by a combination of factors, including concurrent disease, complexity of the operation, and adverse effects of anesthesia.
Patients were evaluated the night before surgery. Higher-risk patients should be evaluated in a preoperative evaluation clinic one or more days preoperatively.
*physical status classification
1. Patien has no organic, physiologic, biochemical or psychiatric disturbance
2. Patien has mild to moderate systemic disturbance (eg. Essential hypertension, diabetes mellitus)
3. Patien has severe systemic disturbance
(eg. Heartdisease)
4. Patient has severe systemic disturbance that is life-threatening with or without surgery (eg. Congestive heart failure, persistent angina pectoris)
5. Patien is moribund and has little chance for survival, but surgery is to be performed as a last resort (eg. Uncontrolled hemorhage as from a ruptured abdominal aneurysm.
History and physical examination
The history shuld include a review of the patients previous experience with anesthesia, and data should be elicited regarding any allergic reactions, delayed aweking, prolonged paralysis from neuromuscular blocking drugs, and jaundice. The presence and severity of any concurrent disease(eg. Hepatitis), coagulopathies, diabetes mellitus or cardiorespiratory dysfunction should be note. Social history : drug, alcohol, and tobacco use and famili history.
The physical examination should focus on the cardiovascular system, lungs, and upper airway. If abnormalities are found, additional test (ecg, pulmonary function tests, etc) may be indicated.
Laboratory test
Eg, Elective surgery should not be performed if the hemoglobin concentration is less than 10 g/dl. More important is the need to determine why the patient is anemic.
Informed consent
Key components of an informed consent include decision-making capacity, patient voluntariness, disclosure, preferences of the reasonable person, legal issues in disclosure, recommendations, the patients understanding, clinical decisions, and autonomous authorization. The patient should be allowed to ask questions.