A Single Session of Exercise Reduces Blood Pressure Reactivity to Stress: a Systematic Review With Meta-analysis

Stressful situations are common in everyday life and disturb homeostasis. So, an exercise session is a strategy to mitigate blood pressure (BP) peaks in response to stress (i.e., BP reactivity), decreasing the cardiovascular risk of these individuals. This is a systematic review with a meta-analysis that aims to verify the effects of a single session of physical exercises on BP reactivity to stress. The searches were realized in digital databases (PUBMED, LILACS, EMBASE and PsycInfo) and 28 studies were included, totaling 846 individuals (meta-analysis stage: k = 24, n = 710). As for exercise characteristics, 23 of the 28 studies focused on aerobic exercises, and 24 studies focused on low to moderate intensities. Favorable metanalytic results (standardized mean differences through random-effects approach) for the exercises were found, with attenuated reactivity in systolic BP (pooled effect size = -0.35 [-0.46; -0.23], representing average reductions of 3.8 ± 3.5 mmHg), diastolic BP (pooled effect size = -0.49 [-0.68; -0.30], representing average reductions of 3.1 ± 3.6 mmHg), and mean BP (pooled effect size = -0.48 [-0.70; -0.26], representing average reductions of 4.1 ± 3.0 mmHg). So, acute physical exercise lowers systolic, diastolic, and mean blood pressure reactivity in response to stressor tasks.

Physiologic Characteristics of Hyperosmolar Therapy After Pediatric Traumatic Brain Injury

All work was performed at the Barrow Neurological Institute at Phoenix Children's Hospital.Objective: Investigate injury severity, neuroimaging, physiology, and outcomes with bolus hyperosmolar therapy (HT) of 3% hypertonic saline or mannitol.Methods: Retrospective cohort analysis was performed. Physiologic variables included intracranial pressure (ICP), arterial blood pressure (ABP), and heart rate (HR). Volume-pressure compensation (PVC) indices included ICP pulse amplitude (AMP) and correlation of AMP and ICP (RAP). Cerebrovascular pressure reactivity (CVPR) indices included pressure reactivity index (PRx), pulse amplitude index (PAx), wavelet PRx (wPRx), and correlation of AMP and cerebral perfusion pressure (RAC). Heart rate variability (HRV) indices included heart rate standard deviation (HRsd), heart rate root mean square of successive differences (HRrmssd) and low-high frequency ratio (LHF). Outcome was assessed using Glasgow Outcomes Scale Extended Pediatrics, 12-months post-injury. Generalized estimating equations was applied to investigate associations of physiologic changes and pre-treatment indices with HT efficacy. Repeated measures analysis of variance was applied to investigate changes after HT without intracranial hypertension (ICH). Wilcoxon rank-sum was applied to investigate HT responsiveness with age, injury severity, neuroimaging, and outcomes.Results: Thirty children received bolus HT. ICH reduction after HT was associated with reduced ICP (p = 0.0064), ABP (p = 0.0126), PRx (p = 0.0063), increased HRsd (p = 0.0408), and decreased pretreatment RAC (p = 0.0115) and wPRx (p = 0.0072). HT-responsive patients were older and had improved outcomes (p = 0.0394). HT without ICH was associated with increased ICP (P < 0.0001) and ABP (P < 0.0001), increases in all HRV indices and decreases in all PVC indices.Conclusion: After pediatric TBI, efficacious HT is associated with decreased ICP and ABP, pre-treatment indices suggesting efficient CVPR, and potentially improved outcomes.