Background: There is controversy about whether patients who take
exogenous glucocorticoids, such as prednisone, require supplemental
(exogenous) glucocorticoids in order to meet the physiological demands of
surgery. In this study, we sought to define the magnitude of the surgical
stress response in normal patients undergoing major and minor elective
Methods: A prospective, observational study of thirty patients who
had not taken exogenous glucocorticoids and who underwent either elective knee
arthroscopy or elective unilateral total knee arthroplasty was performed.
Regional anesthesia was used for all patients, and all patients treated with
total knee arthroplasty had continuous epidural anesthesia for forty-eight
hours after the surgery. The stress response was assessed on the basis of
serum and twenty-four-hour urine cortisol levels; comparisons of the urine
values were made after correcting for renal function by calculating the
cortisol-to-creatinine clearance ratio.
Results: Preoperatively, patients undergoing arthroscopy and total
knee arthroplasty had similar cortisol-to-creatinine clearance ratios.
Patients treated with total knee arthroplasty had a significant (p < 0.001)
surgical stress response on the day of the surgery, compared with baseline,
whereas patients treated with arthroscopy did not. The mean
cortisol-to-creatinine clearance ratio in patients treated with total knee
arthroplasty was highest on the day of the surgery and decreased on the third
postoperative day. However, on the third postoperative day, the
cortisol-to-creatinine clearance ratio still was significantly higher than the
baseline value (p < 0.001). Significant differences in the serum cortisol
levels also were detected between the patients treated with arthroscopy and
those treated with total knee replacement.
Conclusions: Patients undergoing total knee arthroplasty had a
significant surgical stress response (a seventeenfold increase in the
cortisol-to-creatinine clearance ratio); patients treated with arthroscopy did
not. Additional studies, including a prospective trial of patients taking
exogenous glucocorticoids, are warranted. Until they are performed, the
significantly increased cortisol production observed in non-steroid-dependent
patients following total knee arthroplasty leaves open the possibility that
steroid-dependent patients undergoing this procedure could benefit from
perioperative glucocorticoid supplementation. Since the non-steroid-dependent
patients in the present series did not mount a substantial stress response to
knee arthroscopy, our results do not support the use of supplemental steroids
for that less-invasive procedure.
Level of Evidence: Therapeutic study, Level II-1
(prospective cohort study). See Instructions to Authors for a complete
description of levels of evidence.