New Findings: What is the central question of this study? Is blood flow regulation to hypoxia different between the internal carotid arteries (ICAs) and vertebral arteries (VAs), and what is the measurement error in unilateral extracranial artery assessments compared to bilateral? What is the main finding and its importance? ICA and VA blood flow regulation to hypoxia is comparable when factoring for vessel type and vessel side. Compared to bilateral assessment, vessels assessed unilaterally had individual measurement errors of up to 37%. Assessing the vessel with the larger resting blood flow, not the left or right vessel, reduces unilateral measurement error. Whether blood flow regulation to hypoxia is similar between left and right internal carotid arteries (ICAs) and vertebral arteries (VAs) is unclear. Extracranial blood flow is regularly calculated by doubling a unilateral assessment; however, lateral artery differences may lead to measurement error. This study aimed to determine extracranial blood flow regulation to hypoxia when factoring for vessel type (ICAs or VAs) and vessel side (left or right) effects, and to investigate unilateral assessment measurement error compared to bilateral assessment. In a repeated‐measures crossover design, extracranial arteries of 44 participants were assessed bilaterally by duplex ultrasound during 90 min of normoxic and poikilocapnic hypoxic (12.0% fraction of inspired oxygen) conditions. Linear mixed model analyses revealed no Condition × Vessel Type × Vessel Side interaction for blood flow, vessel diameter and flow velocity (all P > 0.05) indicating left and right ICA and VA blood flow regulation to hypoxia was similar. Bilateral hypoxic reactivity was comparable (ICAs, 1.4 (1.0) vs. VAs, 1.7 (1.1) Δ%·Δ⁻¹; P = 0.12). Compared to bilateral assessment, unilateral mean measurement error of the relative blood flow response to hypoxia was up to 5%, but individual errors reached 37% and were greatest in ICAs and VAs with the smaller resting blood flow due to a ratio‐scaling problem. In conclusion, left and right ICA and VA regulation to hypoxia is comparable when factoring for vessel type and vessel side. Assessing the ICA and VA vessels with the larger resting blood flow, not the left or right vessel, reduces unilateral measurement error.

Tackling poor mental health and wellbeing among healthcare workers remains a high priority for the National Health Service (NHS). This study evaluated the social value of the Coming to Our Senses mindfulness-based programme, designed to support the mental health of workers in high-stress medical environments, for NHS healthcare workers in Wales. Respondents (N = 39) to an online survey were assessed for mental health social value at baseline and one-month follow-up using the Short Warwick–Edinburgh Mental Wellbeing Scale (SWEMWBS) and the Social Value Bank (SVB). Social return on investment (SROI) ratios were calculated by dividing the change in mental health social value, health resource service use, and productivity costs by the programme delivery costs. Social value generated per respondent was £1890.05 using SWEMSWBS and £5775.97 using SVB. Cost savings in health resource and productivity were £9.41 and £79.10 per respondent, respectively. The programme delivery cost was £463.63 per respondent. Overall, including sensitivity analysis, the programme yielded a positive SROI of £2.35–£4.27:£1 using SWEMWBS or £6.82–£12.65:£1 using SVB. These findings suggest that the Coming to Our Senses programme may be effective in generating positive social value by improving self-reported mental health and wellbeing among NHS healthcare workers in Wales.

We demonstrate that hypoxia causes regional dynamic cerebral autoregulation (dCA) in males, where volumetric dCA was reduced in the vertebral artery but not the internal carotid artery. In addition, immediately before the dCA assessment, the vertebral artery diameter was unchanged, whereas the internal carotid artery diameter was increased. In combination, these findings challenge the prevailing view that reductions in dCA in hypoxia are due to a reduction in vascular tone.