Background: Impaired exercise tolerance during formal testing is predictive
of perioperative complications. However, for most patients, formal exercis
e testing is not indicated, and exercise tolerance is assessed by history.
Objective: To determine the relationship between self-reported exercise tol
erance and serious perioperative complications.
Methods: Our study group consisted of 600 consecutive outpatients referred
to a medical consultation clinic at a tertiary care medical center for preo
perative evaluation before undergoing 612 major noncardiac procedures. Pati
ents were asked to estimate the number of blocks they could walk and Rights
of stairs they could climb without experiencing symptomatic limitation. Pa
tients who could not walk 4 blocks and climb 2 flights of stairs were consi
dered to have poor exercise tolerance. All patients were evaluated for the
development of 26 serious complications that occurred during hospitalizatio
n.
Results: Patients reporting poor exercise tolerance had more perioperative
complications (20.4% vs 10.4%; P < .001). Specifically, they had more myoca
rdial ischemia (P = .02) and more cardiovascular (P = .04) and neurologic (
P = .03) events. Poor exercise tolerance predicted risk for serious complic
ations independent of all other patient characteristics, including age (adj
usted odds ratio, 1.94; 95% confidence interval, 1.19-3.17). The likelihood
of a serious complication occurring was inversely related to the number bl
ocks that could be walked (P = .006) or flights of stairs that could be cli
mbed (P = .01). Other patient characteristics predicting serious complicati
ons in multivariable regression analysis included history of congestive hea
rt failure, dementia, Parkinson disease, and smoking greater than or equal
to 20 pack-years.
Conclusion: Self-reported exercise tolerance can be used to predict in-hosp
ital perioperative risk, even when using relatively simple and familiar mea
sures.