When is it safe to start venous thromboembolism prophylaxis after blunt solid organ injury? A prospective American Association for the Surgery of Trauma multi-institutional trial.

BACKGROUND: The optimal time to initiate venous thromboembolism (VTE) chemoprophylaxis (VTEp) after blunt solid organ injury remains controversial, as VTE mitigation must be balanced against bleeding promulgation. Evidence from primarily small, retrospective, single-center work suggests that VTEp ≤48 hours is safe and effective. This study was undertaken to validate this clinical practice. METHODS: Blunt trauma patients presenting to 19 participating trauma centers in North America were screened over a 1-year study period beginning between August 1 and October 1, 2021. Inclusions were age older than 15 years; ≥1 liver, spleen, or kidney injury; and initial nonoperative management. Exclusions were transfers, emergency department death, pregnancy, and concomitant bleeding disorder/anticoagulation/antiplatelet medication. A priori power calculation stipulated the need for 1,158 patients. Time of VTEp initiation defined study groups: Early (≤48 hours of admission) versus Late (>48 hours). Bivariate and multivariable analyses compared outcomes. RESULTS: In total, 1,173 patients satisfied the study criteria with 571 liver (49%), 557 spleen (47%), and 277 kidney injuries (24%). The median patient age was 34 years (interquartile range, 25-49 years), and 67% (n = 780) were male. The median Injury Severity Score was 22 (interquartile range, 14-29) with Abbreviated Injury Scale Abdomen score of 3 (interquartile range, 2-3), and the median American Association for the Surgery of Trauma grade of solid organ injury was 2 (interquartile range, 2-3). Early VTEp patients (n = 838 [74%]) had significantly lower rates of VTE (n = 28 [3%] vs. n = 21 [7%], p = 0.008), comparable rates of nonoperative management failure (n = 21 [3%] vs. n = 12 [4%], p = 0.228), and lower rates of post-VTEp blood transfusion (n = 145 [17%] vs. n = 71 [23%], p = 0.024) when compared with Late VTEp patients (n = 301 [26%]). Late VTEp was independently associated with VTE (odd ratio, 2.251; p = 0.046). CONCLUSION: Early initiation of VTEp was associated with significantly reduced rates of VTE with no increase in bleeding complications. Venous thromboembolism chemoprophylaxis initiation ≤48 hours is therefore safe and effective and should be the standard of care for patients with blunt solid organ injury. LEVEL OF EVIDENCE: Therapeutic and Care Management; Level III.

United States Army physical readiness training: rationale and evaluation of the physical training doctrine.

This paper reviews the rationale and evaluations of Physical Readiness Training (PRT), the new U.S. Army physical training doctrine designed to improve soldiers' physical capability for military operations. The purposes of PRT are to improve physical fitness, prevent injuries, progressively train soldiers, and develop soldiers' self-confidence and discipline. The PRT follows the principles of progressive overload, regularity, specificity, precision, variety, and balance. Specificity was achieved by examining the standard list of military (warrior) tasks and determining 1) the physical requirements, 2) the fitness components involved, and 3) the training activities that most likely could improve the military tasks. Injury-prevention features include reduced running mileage, exercise variety (cross-training), and gradual, progressive training. In 3 military field studies, the overall adjusted risk of injury was 1.5-1.8 times higher in groups of soldiers performing traditional military physical training programs when compared with groups using a PRT program. Scores on the Army Physical Fitness Test were similar or higher in groups using PRT programs. In an 8-week laboratory study comparing PRT with a weightlifting/running program, both programs resulted in major improvements in militarily relevant tasks (e.g., 3.2-km walk/run with 32-kg load, 400-m run with 18-kg load, 5- to 30-second rushes to and from prone position, 80-kg casualty drag, obstacle course). When compared with traditional military physical training programs, PRT consistently resulted in fewer injuries and in equal or greater improvements in fitness and military task performance.

The basis for prescribed ability group run speeds and distances in U.S. Army basic combat training.

During the first few days of Army Basic Combat Training (BCT), recruits take a running test and after completing this test they are ranked from fast to slow. Four roughly equal-sized "ability groups" are established from these rankings and recruits run together in these groups for their physical training during BCT. In the past, there has been no formal guidance regarding how fast or how far these ability groups should run. To fill this void, this study provides guidance for running speeds and distances during BCT. The major considerations included are: (1) minimizing injuries, (2) the initial aerobic fitness level of recruits, (3) historical improvements in run times during BCT, (4) historical running speeds of the slower individuals in each ability group, (5) running speeds that must be achieved to "pass" the 2-mile run in BCT, (6) the gender composition of the ability groups, and (7) recommendations from the trainers and field testing. Three databases were analyzed that contained a total of 16,716 men and 11,600 women. Four steps were used in the analyses: (1) establishment of run-time cut points for representative ability groups, (2) determination of initial (starting) run speeds, (3) estimation of changes in run speeds with training, and (4) establishment of run speeds and distances for each week of BCT. Efforts were made to (1) keep the running speeds between 70% and 83% of the estimated maximal oxygen uptake (VO2max) for all ability groups, (2) consider the 2-mile running pace of the slower individuals in each ability group, and (3) keep the total running distance for the two slower ability groups below a total of 25 miles, the apparent threshold for increasing injury incidence. A chart provides speeds and distances for each ability group at each week of BCT. Using these recommended speeds and distances should allow trainees to improve their aerobic fitness, pass the Army Physical Fitness Test, and minimize injuries that result in lost training time and, ultimately, lower fitness levels.

Increasing the physical fitness of low-fit recruits before basic combat training: an evaluation of fitness, injuries, and training outcomes.

Recruits arriving for basic combat training (BCT) between October 1999 and May 2004 were administered an entry-level physical fitness test at the reception station. If they failed the test, then they entered the Fitness Assessment Program (FAP), where they physically trained until they passed the test and subsequently entered BCT. The effectiveness of the FAP was evaluated by examining fitness, injury, and training outcomes. Recruits who failed the test, trained in the FAP, and entered BCT after passing the test were designated the preconditioning (PC) group (64 men and 94 women). Recruits who failed the test but were allowed to enter BCT without going into the FAP were called the no preconditioning (NPC) group (32 men and 73 women). Recruits who passed the test and directly entered BCT were designated the no need of preconditioning (NNPC) group (1,078 men and 731 women). Army Physical Fitness Test (APFT) scores and training outcomes were obtained from a company-level database, and injured recruits were identified from cases documented in medical records. The proportions of NPC, PC, and NNPC recruits who completed the 9-week BCT cycle were 59%, 83%, and 87% for men (p < 0.01) and 52%, 69%, and 78% for women (p < 0.01), respectively. Because of attrition, only 63% of the NPC group took the week 7 APFT, compared with 84% and 86% of the PC and NNPC groups, respectively. The proportions of NPC, PC, and NNPC recruits who passed the final APFT after all retakes were 88%, 92%, and 98% for men (p < 0.01) and 89%, 92%, and 97% for women (p < 0.01), respectively. Compared with NNPC men, injury risk was 1.5 (95% confidence interval, 1.0-2.2) and 1.7 (95% confidence interval, 1.0-3.1) times higher for PC and NPC men, respectively. Compared with NNPC women, injury risk was 1.2 (95% confidence interval, 0.9-1.6) and 1.5 (95% confidence interval, 1.1-2.1) times higher for PC and NPC women, respectively. This program evaluation showed that low-fit recruits who preconditioned before BCT had reduced attrition and tended to have lower injury risk, compared with recruits of similar low fitness who did not precondition.

Evaluation of a standardized physical training program for basic combat training.

A control group (CG, n = 1,138) that implemented a traditional Basic Combat Training (BCT) physical training (PT) program was compared to an evaluation group (EG, n = 829) that implemented a PT program newly designed for BCT. The Army Physical Fitness Test (APFT) was taken at various points in the PT program, and injuries were obtained from a medical surveillance system. After 9 weeks of training, the proportion failing the APFT was lower in the EG than in the CG (1.7 vs. 3.3%, p = 0.03). After adjustment for initial fitness levels, age, and body mass index, the relative risk of an injury in the CG was 1.6 (95% confidence interval [CI] =1.2-2.0) and 1.5 (95% CI = 1.2-1.8) times higher than in the EG for men and women, respectively. The newly designed PT program resulted in higher fitness test pass rates and lower injury rates compared to a traditional BCT physical training program.