Mobile Stroke Unit in the UK Healthcare System: Avoidance of Unnecessary Accident and Emergency Admissions.

BACKGROUND: Acute stroke patients are usually transported to the nearest hospital regardless of their required level of care. This can lead to increased pressure on emergency departments and treatment delay. OBJECTIVE: The aim of the study was to explore the benefit of a mobile stroke unit (MSU) in the UK National Health Service (NHS) for reduction of hospital admissions. METHODS: Prospective cohort audit observation with dispatch of the MSU in the East of England Ambulance Service area in Southend-on-Sea was conducted. Emergency patients categorized as code stroke and headache were included from June 5, 2018, to December 18, 2018. Rate of avoided admission to the accident and emergency (A&E) department, rate of admission directly to target ward, and stroke management metrics were assessed. RESULTS: In 116 MSU-treated patients, the following diagnoses were made: acute stroke, n = 33 (28.4%); transient ischaemic attacks, n = 13 (11.2%); stroke mimics, n = 32 (27.6%); and other conditions, n = 38 (32.8%). Pre-hospital thrombolysis was administered to 8 of 28 (28.6%) ischaemic stroke patients. Pre-hospital diagnosis avoided hospital admission for 29 (25.0%) patients. As hospital treatment was indicated, 35 (30.2%) patients were directly triaged to the stroke unit, 1 patient (0.9%) even directly to the catheter laboratory. Thus, only 50 (43.1%) patients required transfer to the A&E department. Moreover, the MSU enabled thrombolysis with a median dispatch-to-needle time of 42 min (interquartile range, 40-60). CONCLUSION: This first deployment of an MSU in the UK NHS demonstrated improved triage decision-making for or against hospital admission and admission to the appropriate target ward, thereby reducing pressure on strained A&E departments.

Behaviour of [11C]R(-)- and [11C]S(+)-rolipram in vitro and in vivo, and their use as PET radiotracers for the quantificative assay of PDE4.

Cyclic AMP (cAMP) is a continually produced nucleotide which is inactivated by hydrolysis to 5'AMP via phosphodiesterase 4 (PDE4) enzymes. Rolipram is a selective PDE4 inhibitor which exists in two enantiomeric forms, R(-) and S(+). Both of these enantiomers have previously been labelled with carbon-11 and used as positron emission tomography (PET) ligands for measuring PDE4 expression and function, and indirectly to explore the function of the cAMP second messenger, in vivo, using PET. The aim of these studies was to relate the in vitro affinities of the two rolipram enantiomers using standard pharmacological assays with the in vivo behaviour of the two enantiomers using PET. In vitro competition assays were performed using rat cortical membranes and [(3)H]R(-)- and [(3)H]S(+)-rolipram with increasing concentrations of either unlabelled R(-)- or S(+)-rolipram. In vivo, a series of PET studies were performed in the porcine brain using [(11)C]R(-)-rolipram with co-administration of increasing doses of either unlabelled R(-)- or S(+)-rolipram. Additional in vivo PET studies were performed using [(11)C]S(+)-rolipram with saturating doses of rolipram. In all studies, R(-)-rolipram exhibited a higher affinity for the PDE4 enzyme than S(+)-rolipram. The calculated affinity ratios were 7.97 from the in vitro studies; 12.5 from the in vivo studies using [(11)C]R(-)-rolipram; and 14.7 from the in vivo studies using [(11)C]S(+)-rolipram. To conclude, the in vitro affinities of R(-)- and S(+)-rolipram predict their apparent in vivo behaviour in the porcine brain, as measured by PET.