Preferences of the anesthesiologist or anesthetist and the patient.
The skill of the anesthesiologist or anesthetist.
c. Factors considered by the anesthetist or anesthesiologist when selecting an
agent are the smoking and drinking habits of the patient, any medications the patient is
taking, and the presence of disease. Of particular concern are pulmonary function, hepatic
function, renal function, and cardiovascular function.
(1) Pulmonary function is adversely affected by upper respiratory tract
infections and chronic obstructive lung diseases such as emphysema, especially when
intensified by the effects of general anesthesia. These conditions also predispose the
patient to postoperative lung infections.
(2) Liver diseases such as cirrhosis impair the ability of the liver to detoxify
medications used during surgery, to produce the prothrombin necessary for blood clotting,
and to metabolize nutrients essential for healing following surgery.
(3) Renal insufficiency may alter the excretion of drugs and influence the
patient's response to the anesthesia. Regulation of fluids and electrolytes, as well as acid-
base balance, may be impaired by renal disease.
(4) Well-controlled cardiac conditions pose minimal surgical risks. Severe
hypertension, congestive heart failure, or recent myocardial infarction drastically increase
d. Medications, whether prescribed or over-the-counter, can affect the patient's
reaction to the anesthetic agent, increase the effects of the anesthesia, and increase the
risk from the stress of surgery. Medication is usually withheld when the patient goes to
surgery; but some specific medications are given even then. For example, patients with
cardiovascular problems or diabetes mellitus may continue to receive their prescribed
(1) Because some medications interact adversely with other medications and
with anesthetic agents, preoperative assessment should include a thorough medication
history. Patients may be taking medication for conditions unrelated to the surgery, and
are unaware of the potential for adverse reactions of these medications with anesthetic
Drugs in the following categories increase surgical risk.
(a) Adrenal steroids--abrupt withdrawal may cause cardiovascular
collapse in long-term users.