Estimated glomerular filtration rate versus creatinine clearance to
determine anticoagulant dosage after lower-limb orthopedic surgery
Abstract
Aim: This retrospective study aimed to determine whether different renal
function estimation formulas affect the incidence of venous
thromboembolism (VTE) and bleeding when anticoagulant dosages are
determined. Methods: The study included patients who underwent
lower-limb orthopedic surgery and were treated with anticoagulants
between January 2017 and March 2020 at Yaizu City Hospital. The
appropriateness of anticoagulant dosing was assessed using creatinine
clearance (CCr), estimated glomerular filtration rate (eGFR), and
de-indexed eGFR without correction for body surface area, and the
incidence of VTE and bleeding was compared among the different renal
function estimation formulas. Results: The median values for body
surface area, CCr, eGFR, and de-indexed eGFR were
1.40m2, 56.0mL/min,
73.0mL/min/1.73m2, and 60.9mL/min, respectively. There
was no significant difference in the incidence of VTE among the
different renal function estimation formulas. However, when the
threshold for dose reduction or contraindication was determined by eGFR
rather than CCr, the incidence of bleeding was significantly higher in
the group that was overdosed in CCr (6.0% vs 25.7% p<0.05).
Similarly, when the threshold for dose reduction or contraindication was
determined by de-indexed eGFR rather than CCr, the incidence of bleeding
was significantly higher in the group that was overdosed in CCr (7.5%
vs 28.6% p<0.05). Conclusion: It is necessary to set the
dosage of anticoagulants based on CCr for patients with a small body
surface area in the field of orthopedics to avoid the risk of bleeding.