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Objective: To noninvasively explore the heat intolerance condition during exercise-heat stress by assessing cardiovascular (CV) performance. Design: Prospective study of participants undergoing a standard heat-tolerance test (HTT). Setting: Institutional study. Participants: Ninety-five young males: 16 heat-intolerant (HI) and 79 heat-tolerant (HT). Interventions: Cardiovascular performance during an HTT was estimated by heart rate (HR) and blood pressure measurements. Main outcome measures: The sensitivity of the cardiovascular reserve index (CVRI) and the dynamic heart rate reserve (dHRR) index to predict heat intolerance was compared. Results: A significant difference in the CV reserve during exercise-heat stress was exhibited between the HI and the HT groups. Starting at a similar level, the reduction in the CV reserve at HTT endpoint was much greater in the HI than the HT individuals (P < 0.0001), as depicted by both the CVRI and the dHRR. This result indicates a greater utilization of the CV reserve by HI individuals. The CVRI is likely to be better predictor of heat intolerance than the dHRR because the partial area under the curve in the high sensitivity (>90%) region of its receiver operating characteristic curve is higher (93.2 vs 76.8). Conclusions: More than being a predictor, the CVRI may provide a new clinical insight into heat intolerance because it noninvasively characterizes the efficiency of an individual's thermoregulatory mechanism and hints that an impaired CV reserve might underlie heat intolerance. The CVRI provides a noninvasive measurement of thermoregulation, which has been long awaited to enable on-field studies and dynamic monitoring of heat-exposed task forces. [ABSTRACT FROM AUTHOR]

Background: Previous research has detected an increased risk of stress fractures among subjects who reported previous use of methylphenidate. Conversely, stimulant medication use has been associated with traumatic fracture risk reduction, possibly because of the improved control of the underlying symptoms of attention deficit hyperactivity disorder (ADHD). The goal of this study was to investigate the effect of previous methylphenidate use on the incidence of traumatic and stress fractures among combat soldiers with previously treated and untreated ADHD.Methods: The retrospective cohort included 100,000 combat soldiers recruited to the Israeli Defense Forces from 2005 through 2015. Diagnosis of ADHD and previous exposure to methylphenidate were determined on the basis of self-reported recruitment questionnaires and medical records. Accordingly, the cohort was divided into 3 groups: subjects with ADHD who were previously treated with methylphenidate (n = 689), untreated subjects with ADHD reporting no medication use (n = 762), and controls having no ADHD diagnosis (n = 98,549). Logistic regressions were fitted to determine the odds ratios (ORs) of study subjects for stress and non-stress (traumatic) fractures. Multivariate analysis incorporated baseline characteristics, including age, sex, weight, duration of service, and diagnosis of anemia, at some point during the service.Results: After adjustment for sex, anemia, weight, age, and duration of service, the risk of traumatic fractures was increased in both subjects with treated ADHD (OR, 1.03 [95% confidence interval (CI), 1.00 to 1.05]) and subjects with untreated ADHD (OR, 1.04 [95% CI, 1.02 to 1.07]) compared with controls. Subjects in the treated ADHD group were at a higher risk of stress fractures (OR, 1.04 [95% CI, 1.02 to 1.07]). Interestingly, a diagnosis of anemia was an independent predictor of stress fractures (OR, 1.05 [95% CI, 1.04 to 1.06]).Conclusions: Methylphenidate use is associated with an increased risk of stress fractures but a decreased risk of traumatic fractures in individuals diagnosed with ADHD. These and previous findings may serve as sufficient basis for screening for other risk factors and perhaps taking prevention measures in all those using stimulant medications, especially those planning to engage in strenuous physical activity.Level Of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Study Design: A case report.Objective: Presentation of a patient diagnosed with perforation of the aorta by pedicle screws at levels T6 and T9 2 years after spinal fusion, who was advised no intervention. Review of other reported cases that did not undergo excision of the penetrating screws.Summary Of Background Data: More than 30 cases of aortic penetration by pedicle screws were described. Gradual penetration of the screws into the aorta rarely causes symptoms other than backache. However, only two cases were treated conservatively.Methods: A 65-year-old female patient underwent spinal decompression and T5-T10 posterior fusion following a spinal abscess. Two years and 8 months postoperatively, she underwent a computed tomography scan for suspicion of spinal hardware infection, which showed T6 and T10 screws penetrating the thoracic aorta.Results: Due to high morbidity, the patient was not offered an operation for screw excision.Conclusion: This case report adds to the only two previous reports of patients who did not undergo revision of pedicle screws penetrating thoracic aorta.Level Of Evidence: 5. [ABSTRACT FROM AUTHOR]