Understanding Anesthesiology - The Global Regional Anesthesia ...

are known to have cardiac disease or in whom risk factors
(including age) are present. Routine pre-operative
chest x-rays are not required prior to most procedures.
The anesthesiologist will commonly assign an “ASA
class” (Table 6) to the patient. The ASA (American Society
of Anesthesiologists) classification was defined in
the 1940‘s as an attempt to identify operative risk. As
the patient’s underlying health is the most important
determinant of peri-operative risk, the ASA class does
correlate (somewhat) to overall peri-operative risk.
Though it does not lend itself to inter-rater reliability, it
is an accepted method of communicating the overall
physical condition of the patient and the learner should
become accustomed to applying this scale to the patients
he or she encounters.
Table 6 ASA classification
ASA CLASS
1
2
3
4
DESCRIPTION
A normal healthy patient in need of surgery
for a localized condition.
A patient with mild to moderate systemic
disease; examples include controlled
hypertension, mild asthma.
A patient with severe systemic disease;
examples include complicated diabetes,
uncontrolled hypertension, stable angina.
A patient with life-threatening systemic
disease; examples include renal failure or
unstable angina.
5
A moribund patient who is not expected to
survive 24 hours with or without the
operation; examples include a patient with
a ruptured abdominal aortic aneurysm in
profound hypovolemic shock.
34