Cardiovascular Effects of Compression Garments During Uncompensable Heat Stress.

ABSTRACT: Bautz, J, Hostler, D, Khorana, P, and Suyama, J. Cardiovascular effects of compression garments during uncompensable heat stress. J Strength Cond Res 35(4): 1058-1065, 2021-This study examined the potential hemodynamic benefits of wearing lower extremity compression garments (CGs) beneath thermal protective clothing (TPC) worn by wildland firefighters, while exercising in a heated environment. Using in a counterbalanced design, 10 male subjects ([mean ± SD] age 27 ± 6 years, height 1.78 ± 0.09 m, body mass 74.8 ± 7.0 kg, body fat 10.6 ± 4.2%, and V̇o2max 57.8 ± 9.3 ml·kg-1·min-1) completed control (no CG) and experimental (CG) conditions in randomly assigned order. Protocols were separated by a minimum of 3 days. Subjects exercised for 90 minutes (three, 30-minute segments) on a treadmill while wearing wilderness firefighter TPC and helmet in a heated room. Venous blood was drawn before and after exercise to measure hemoglobin (Hgb), hematocrit (Hct), serum osmolarity (OSM), and serum creatine phosphokinase (CPK). Vital signs and perceptual measures of exertion and thermal comfort were recorded during the protocol. Data were analyzed by the paired t-test. There were no differences in the change in heart rate (84 ± 27 vs. 85 ± 14 b·min-1, p = 0.9), core temperature rise (1.8 ± 0.6 vs. 1.9 ± 0.5° C, p = 0.39), or body mass lost (-1.72 ± 0.78 vs. -1.77 ± 0.58 kg, p = 0.7) between the conditions. There were no differences in the change in Hgb (0.49 ± 0.66 vs. 0.33 ± 1.11 g·dl-1, p = 0.7), Hct (1.22 ± 1.92 vs. 1.11 ± 3.62%, p = 0.9), OSM (1.67 ± 6.34 vs. 6.22 ± 11.39 mOsm·kg-1, p = 0.3), or CPK (22.2 ± 30.2 vs. 29.8 ± 19.4 IU·L-1, p = 0.5). Total distance walked (3.9 ± 0.5 vs. 4.0 ± 0.5 miles, p = 0.2), exercise interval (88.6 ± 3.5 vs. 88.4 ± 3.6 minutes, p = 0.8), and perceptual measures were similar between conditions. Compression garments worn beneath TPC did not acutely alter the physiologic response to exertion in TPC. With greater use in the general public related to endurance activities, the data neither encourage nor discourage CG use during uncompensable heat stress.

Pain Is Inevitable But Suffering Is Optional: Relationship of Pain Coping Strategies to Performance in Multistage Ultramarathon Runners.

INTRODUCTION: Ultramarathon runners commonly endure musculoskeletal pain during endurance events. However, the effect of pain coping skills on performance has not been examined. METHODS: A prospective observational study during three 250 km (155 mi), 6 stage ultramarathons was conducted. Finish line surveys were completed after each of the four 40 km (25 mi) and one 80 km (50 mi) stages of racing. Variables gathered included pain intensity, pain coping strategy use, pain interference, finishing position (quintile), and successful race completion. RESULTS: A total of 204 participants (age 41.4±10.3 y; 73% male) reported average pain intensity of 3.9 (±2.0 SD) and worst pain intensity of 5.3 (±2.3) on a 0 to 10 scale. They used greater adaptive pain coping strategies (3.0±1.3) relative to maladaptive strategies (1.3±1.1). Worst pain and pain interference increased over each stage of the race for all runners (P<0.001), with worst pain being significantly different by finishing status (P=0.02). Although all runners endured increased pain and interference, the nonfinishers (28 [14%]) had significantly greater differences in changes in pain intensity (P<0.01) and pain interference (P<0.001). Maladaptive pain coping strategies were more common in nonfinishers; with each 1-point increase (0-6 scale), there was a 3 times increase in odds of not finishing the race. CONCLUSIONS: Although increased pain intensity and pain interference was found in all multistage ultramarathon runners, successful event completion was significantly associated with less maladaptive pain coping. Training in coping with pain may be a beneficial part of ultramarathon preparation.

How variability in pain and pain coping relate to pain interference during multistage ultramarathons.

An important and substantial body of literature has established that maladaptive and adaptive coping strategies significantly impact pain-related outcomes. This literature, however, is based primarily on populations with painful injuries and illnesses. Little is known about coping in individuals who experience pain in other contexts and whether coping impacts outcomes in the same way. In an effort to better understand pain coping in such contexts, this study evaluated pain coping in ultramarathon runners, a population known to experience moderate levels of pain with minimal perceived negative effects. This study reports on pain coping in 204 entrants in 2016 RacingThePlanet multistage ultramarathon events. Participants provided data over 5 consecutive days on pain severity, pain interference, exertion, and coping. Results demonstrated that the study participants were more likely to use adaptive than maladaptive coping responses. However, maladaptive coping, but not adaptive coping, was positively associated with percent time spent thinking about pain and pain-related interference. Taken together, the study supports the idea that this high functioning group of individuals experiencing pain emphasizes the use of adaptive coping strategies over maladaptive strategies, reinforcing the perspective that such a pattern may be the most effective way to cope with pain. Within the group, however, results supported traditional patterns, such that greater use of maladaptive strategies was associated with greater pain-related interference, suggesting that optimizing pain coping may be critical to reducing factors that may interfere with ultramarathon performance.

Assessment of platelet transfusion for reversal of aspirin after traumatic brain injury.

BACKGROUND: Platelet transfusion is utilized increasingly for traumatic brain injury (TBI) for the reversal of aspirin (ASA) therapy. Assessment of platelet inhibition and reversal by platelet transfusion after TBI has not been adequately characterized. METHODS: A retrospective cohort analysis of TBI patients at a level I trauma center (January 2008-December 2009) was performed. The Aspirin Response Test (ART; VerifyNow) was used to assess platelet inhibition in TBI patients and guide platelet transfusion in patients with ASA-induced suppression. A follow-up ART was obtained after platelet administration. Primary endpoints were progression of intracranial hemorrhage on computed tomography, need for craniotomy, and mortality. RESULTS: We analyzed 84 patients (median age, 78 [interquartile range, 64-86)]; 54% male). ASA use was documented in 36 (42%) patients. Initial ART indicated platelet dysfunction in 54 (64%) patients, including 42% of patients without a documented history of ASA use. Of the patients with a documented history of ASA, 2.4% had a normal ART. Of those with an initial ART of <550 ASA response units, 45 received platelets. Repeat ART demonstrated reversal of inhibition in 29 patients (64.4%). Initial responders to transfusion received a greater volume of platelets, suggesting a dose-response relationship. Logistic regression revealed a trend toward higher mortality in nonresponders to transfusion (P = .09). Receiver operating characteristic curve analysis revealed that ART results increased prediction of poor outcome compared with ASA history alone (area under the curve = 0.760 and 0.775, respectively). CONCLUSION: The ART should be used to better target and guide platelet transfusions in TBI patients with known or suspected ASA use history. Patients with occult platelet dysfunction can be identified, unnecessary platelet transfusions avoided, and the adequate volume of platelets administered to correct drug-induced dysfunction. A dose-response relationship between quantity of platelets transfused and reversal of ASA inhibition was observed.