Inadequate Enoxaparin Dosing Predicts 90-Day Venous Thromboembolism Risk among Plastic Surgery Inpatients: An Examination of Enoxaparin Pharmacodynamics.

BACKGROUND: Evidence-based plastic surgery guidelines support the effectiveness of once-daily enoxaparin prophylaxis. Despite prophylaxis, one in 25 highest risk patients has a venous thromboembolism event. The authors examined the pharmacodynamics of standard enoxaparin doses in plastic surgery patients to examine whether patient-level factors predict enoxaparin metabolism, whether inadequate enoxaparin dose predicts downstream venous thromboembolism events, and whether a pharmacist-driven dose-adjustment protocol was effective. METHODS: The authors recruited adult plastic surgery patients who received postoperative enoxaparin at 40 mg/day. Steady-state peak anti-factor Xa levels, a marker of enoxaparin effectiveness and safety, were determined. Patients with out-of-range anti-factor Xa levels had real-time dose adjustment based on a written protocol. Patients were followed for 90-day venous thromboembolism events. RESULTS: Ninety-four patients were recruited, and 44 percent had in-range peak anti-factor Xa levels in response to standard enoxaparin dosing. Patient-level factors including extent of surgical injury and gross weight were independent predictors of enoxaparin metabolism. Patients with low anti-factor Xa levels were significantly more likely to have 90-day venous thromboembolism (10.2 percent versus 0 percent; p = 0.041). Real-time dose adjustment allowed a significantly increased proportion of patients to have in-range levels (67.1 percent versus 44.3 percent; p = 0.002). CONCLUSIONS: Based on pharmacodynamic data, the majority of plastic surgery patients receive inadequate enoxaparin prophylaxis using fixed dosing. Patient-level factors can predict how patients will metabolize enoxaparin, and patients who receive inadequate enoxaparin prophylaxis are significantly more likely to have downstream venous thromboembolism events. Individualization of enoxaparin prophylaxis may minimize perioperative venous thromboembolism risk and further improve patient safety after plastic and reconstructive surgery procedures. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.

Microsurgical Reconstruction of Traumatic Lower Extremity Defects in the Pediatric Population.

BACKGROUND: Few reports focus exclusively on microsurgical reconstruction of traumatic lower extremity defects in children. Hence, the authors felt it prudent to contribute to this area of clinical research. The authors hypothesized that reconstructive success would be comparable to success rates reported in adults, and that young age or concerns regarding vessel size or behavior do not negatively impact surgical outcome. METHODS: A retrospective review of microsurgical lower extremity reconstruction cases at two academic medical centers was performed. All pediatric patients who underwent microsurgical reconstruction of traumatic lower extremity defects between 1997 and 2012 were included for analysis. RESULTS: Forty flaps transferred in 40 patients with a mean age of 11.4 years (range, 1 to 17 years) were included for analysis. Muscle flaps were predominantly used [n = 23 (57.5 percent)]; however, there was a recent increase in use of fasciocutaneous flaps [n = 16 (40 percent)]. Postoperative complications were seen in 25 percent of patients, with a total flap loss rate of 5 percent. No donor-site complications were observed. The mean postoperative length of hospital stay was 12.9 days (range, 4 to 41 days), with patients returning to full weight-bearing after a mean of 2.6 months (range, 1 to 8 months). CONCLUSIONS: Microsurgical reconstruction of traumatic lower extremity defects in the pediatric population is safe. Concerns related to patient age, vessel size, or vessel behavior (i.e., vasospasm) should not detract from offering free flap reconstruction, as they do not negatively impact outcomes. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.