Tranexamic acid improves early postoperative mobilization in cancer patients undergoing endoprosthetic reconstruction.

BACKGROUND AND OBJECTIVES: Tranexamic acid (TXA) has been shown to decrease perioperative blood loss, transfusions, and cost in patients undergoing resection of aggressive bone tumors and endoprosthetic reconstruction. This study explored the effect of TXA administration on postoperative mobilization in these patients. METHODS: This study included 126 patients who underwent resection of an aggressive bone tumor and endoprosthetic reconstruction; 61 patients in the TXA cohort and 65 patients in the non-TXA cohort. Postoperative physical therapy (PT) and occupational therapy notes were reviewed; patient ambulation distance and duration of therapies were recorded. RESULTS: Patients in the TXA cohort ambulated further on all postoperative days, which was significant on postoperative Day 1 (POD1) (p = 0.002) and postoperative Day 2 (POD2) (p < 0.001). The TXA cohort ambulated 85% further per PT session 87.7 versus 47.4 ft (p < 0.001) and participated 14% longer, 36.1 versus 31.7 min (p < 0.001). Multivariate analysis identified a significant inverse association between postoperative hospitalization length and POD1, POD2, postoperative Day 3, and total ambulation (p < 0.001). Blood transfusion was independently associated with a 1.5 day increase in postoperative hospitalization (95% confidence interval: 0.64-2.5; p < 0.001). CONCLUSIONS: TXA administration was associated with increased postoperative ambulation and endurance. Increased postoperative ambulation was associated with decreased length of stay and increased likelihood to discharge home.

Radiographic parameters associated with fracture-related infection in high energy bicondylar tibial plateau fractures managed with two-stage treatment: Identifying the bad actors.

INTRODUCTION: High energy tibial plateau fractures are fraught with complications, particularly fracture-related infection (FRI). Previous studies have evaluated patient demographics, fracture classification, and injury characteristics as risk factors for FRI in patients with these injuries. This study evaluated the relationship between radiographic parameters (fracture length relative to femoral condyle width (FLF ratio), initial femoral displacement (FD ratio), and tibial widening (TW ratio)) and fracture-related infection following internal fixation in high energy bicondylar tibial plateau fractures. METHODS: 225 patients treated for bicondylar tibial plateau fractures at two level I trauma centers were retrospectively reviewed. Patient characteristics, fracture classification, and radiographic measurements were analyzed to determine association with FRI. RESULTS: The rate of FRI was 13.8%. Increased fracture length, FLF ratio, FD ratio, TW ratio, and fibula fracture were each associated with FRI on regression analysis, independent of clinical variables. Cutoff values were identified for each parameter and patients were risk stratified based on these radiographic parameters. High-risk patients had a 2.68- and 12.36-times risk of FRI compared to medium and low-risk patients, respectively. DISCUSSION: This study is the first to examine the relationship between radiographic parameters and FRI in high energy bicondylar tibial plateau fractures. Fracture length, FLF ratio, FD ratio, TW ratio, and fibula fracture were identified as radiographic parameters associated with FRI. More importantly, risk stratifying patients based on these parameters accurately identified patients at increased risk of FRI. Not all bicondylar tibial plateau fractures are created equal and radiographic parameters can be utilized to help identify the bad actors.

The effects of cocaine on heart rate and electrocardiogram in zebrafish (Danio rerio).

Zebrafish (Danio rerio) have been used as a model organism to explore the genetic basis for responsiveness to addictive drugs like cocaine. However, very little is known about how the physiological response to cocaine is mediated in zebrafish. In the present study electrocardiograms (ECGs) were recorded from adult zebrafish treated with cocaine. Treatment with cocaine resulted in a bell-shaped dose response curve with a maximal change in heart rate seen using 5mg/L cocaine. Higher doses resulted in a higher percentage of fish showing bradycardia. The cocaine-induced tachycardia was blocked by co-treatment with propranolol, a ß-adrenergic antagonist, but potentiated by co-treatment with phentolamine, an α-adrenergic antagonist. Co-treatment with atropine, a classic cholinergic antagonist, had no effect on cocaine-induced tachycardia. Cocaine treatment of adult fish changed the ECG of treated fish, inducing a dose-dependent increase in QT interval after adjusting for heart rate (QTc), while not affecting the PR or QRS intervals. The acute effects of cocaine on heart rate were examined in 5-day old embryos to see if zebrafish might serve as a suitable model organism to study possible links of embryonic physiological response to subsequent adult behavioral response to the drug. Cocaine treatment of 5-day old zebrafish embryos also resulted in a bell-shaped dose response curve, with maximal tachycardia achieved with 10mg/L. The response in embryonic fish was thus comparable to that in adults and raises the possibility that the effects of embryonic exposure to cocaine on the developing cardiovascular system can be effectively modeled in zebrafish.