Antifibrinolytics Reduced Blood Loss in Study of Adult Spinal Deformity Surgery

Summary

In a surgery known for substantial blood loss (often >5 L) and need for transfusion, two antifibrinolytics significantly reduced the primary outcomes of intraoperative and total blood loss compared with placebo in patients aged =50 years. However, in patients aged <50 years, no significant differences were seenA.

  • Orthopaedics Clinical Trials
  • Spine Conditions
  • Orthopaedic Procedures
  • Orthopaedics
  • Orthopaedics Clinical Trials
  • Spine Conditions
  • Orthopaedic Procedures

In a surgery known for substantial blood loss (often >5 L) and need for transfusion, two antifibrinolytics significantly reduced the primary outcomes of intraoperative and total blood loss (IOBL; TBL) compared with placebo in patients aged ≥50 years. However, in patients aged <50 years, no significant differences were seen, said Thomas Cheriyan, MD, New York University Langone Medical Center, New York, New York, USA.

The prospective, double-blind trial randomized patients undergoing posterior spinal fusion of at least five levels to tranexamic acid (TXA; n=19), epsilon aminocaproic acid (EACA; n=19), or placebo (n=14). Patients with renal dysfunction, coagulation abnormalities, or who could not receive transfusions for religious reasons were excluded. For the analysis of the results, the patients were stratified by age to <50 (n=32) or ≥50 years (n=20), because of statistically significant demographic differences between the treatment groups.

The loading and maintenance doses for TXA were 10 mg/kg and 1 mg/kg/hr, and 100 mg/kg and 10 mg/kg/hr for EACA. TXA and EACA are lysine analogues that inhibit fibrin degradation by blocking the activation of plasminogen to plasmin.

In the patients ≥50 years, IOBL was 1297±520 mL and 1278±523 mL in the TXA and EACA groups respectively compared with 2954±1116 mL in the placebo group (p=0.02), while TBL (IOBL plus postoperative blood drainage) was 3085±1261 mL and 2357±854 mL respectively compared with 5468±2881 mL with placebo (p=0.01).

In the younger patients, IOBL was higher with TXA (2250±1299 mL) and lower with EACA (957±925 mL) compared with placebo (1178±1178 mL; p=0.19). A similar pattern was seen for TBL: 3572±1580 mL with TXA, 2055±748 mL with EACA, and 2687±886 mL with placebo (p=0.09).

For the primary outcome of transfusion rates, there was a broad variation in the intraoperative and postoperative rates between TXA, EACA, and placebo within each age group (Table 1), reflecting the small sample size, said Dr. Cheriyan.

Table 1.

Intraoperative and Postoperative Transfusion Rates

There was no difference in the secondary outcome of preoperative to postoperative change in hematocrit in either age group. Although the sample size was small, no safety issues were seen, he said. There was one pulmonary embolic event each with TXA and EACA. No thromboembolic events or myocardial infarctions occurred.

The investigators plan further study to examine whether there is a dose response for either TXA or EACA and to increase the sample size to address those limitations in the present study.

The editors would like to thank the many members of the American Academy of Orthopaedic Surgeons presenting faculty who generously gave their time to ensure the accuracy and quality of the articles in this publication.

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