ORIGINAL SCIENTIFIC REPORT
Deaths in Incorrectly Identiﬁed Low-Surgical-Risk Patients
C. R. Jones
G. A. J. McCulloch
W. J. Babidge
G. J. Maddern
Published online: 3 January 2018
Internationale de Chirurgie 2018
Background The American Society of Anesthesiologists (ASA) physical classiﬁcation system was developed for
assessing anaesthetic risk, but is often also used to estimate surgical death risk. Patients with low ASA grades (ASA 1
or 2) are expected to have better surgical outcomes than patients with higher ASA grades (ASA C 4). This study
examined the course to death in patients classiﬁed as ASA 1 or 2 was examined, to investigate possible factors in
unexpected deaths, in addition to evaluating the use of ASA grades by clinicians.
Methods Patient data from the national surgical mortality audit of Australian hospitals were examined. The patient
group was listed as ASA grade 1 or 2 by surgeons. Patients over 60 or under 20 were excluded in the ﬁnal analysis, as
were cases from New South Wales due to data not being available. A total of 357 cases were examined. Assessor
summaries of the cases were examined, and ASA score reassessed to determine accuracy.
Results More than 95% (n = 339) of cases listed as ASA 1 or 2 were found to have an incorrectly low grade, with
17.6% (n = 63) of cases listed as ‘‘expected’’ deaths.
Conclusion ASA grades appear to be misunderstood in the reporting of patient surgical risk. Many patient summaries
list patients with severe systemic disease or expected deaths as ASA 1 or 2, contrary to the intended use of this
classiﬁcation system. Improved education on the use of the ASA grading system would be beneﬁcial to clinicians.
The American Society of Anesthesiologists (ASA) physical
status classiﬁcation system is a widely used grading system
for classifying patients based on immediate death risk and
is often used for assessing surgical risk . There are six
possible categories, from a completely healthy person
(ASA 1) to a moribund person not expected to survive
without the operation (ASA 5) with ASA 6 reserved for
brain-dead organ donors. These categories are demon-
strated below (Table 1).
ASA grades are determined by clinical judgement as
opposed to measurable clinical factors, with the assessor
considering factors such as the presence of systemic dis-
ease, the severity of said disease, and the presence of any
comorbidities which would be reasonably expected to
increase death risk . As such, there is expected to be
some minor variation between assessors . Despite this
subjectivity, ASA status is accepted as having high accu-
racy and has been shown to have similar accuracy when
compared to other, more complicated mortality grading
systems such as APACHE II [3, 4].
Healthy patients (ASA 1), or patients with only mild
systemic disease or minor comorbidities (ASA 2) are
& C. R. Jones
Royal Australasian College of Surgeons, ANZASM,
Department of Hepatobiliary and Upper Gastrointestinal
Surgery, The Queen Elizabeth Hospital, Adelaide, SA,
World J Surg (2018) 42:1997–2000