Browsing by Author "Middleton, S."

Now showing 1 - 3 of 3

Blood pressure variability and outcome in acute ischemic and hemorrhagic stroke: a post hoc analysis of the HeadPoST study.
(Scientific & Medical, Macmillan Press, 2019) Minhas, J. S.; Wang, X.; Lavados, P.M.; Moullaali, T.J.; Arima, H.; Billot, L.; Hackett, M.L.; Olavarria, V.V.; Middleton, S.; Pontes-Neto, O.; de Silva, H.A.; Lee, T. H.; Pandian, J. D.; Mead, G. E.; Watkins, C.; Chalmers, J.; Anderson, C.S.; Robinson, T.G.; HeadPoST Investigators
The Head Positioning in Acute Stroke Trial (HeadPoST) is a pragmatic, international, cluster crossover randomized trial of 11,093 patients with acute stroke assigned to a lying-flat (0°) or sitting-up (head elevated ≥30°) position. This post hoc analysis aimed to determine the association between blood pressure variability (BPV) and outcomes for patients from a wide range of international clinical settings and how the association was modified by randomized head position. BPV was defined according to the standard criteria, with the key parameter considered the coefficient of variation (CV) of systolic BP (SBP) over 24 h. Outcome was ordinal 90-day Modified Rankin Scale (mRS) score. The association was analyzed by ordinal, logistic regression, hierarchical, mixed models with fixed intervention (lying flat vs. sitting up), and fixed period, random cluster, and random cluster-period, effects. Nine thousand one hundred and fifty six (8324 acute ischemic stroke and 817 intracerebral hemorrhage; mean age 68.1 years; 39.2% women) were included in the analysis. CV of SBP had a significant linear association with unfavorable shift of mRS at 90 days (adjusted odds ratio 1.06, 95% confidence interval 1.02–1.11; P = 0.01). There was no heterogeneity of the association by randomized head positioning. In addition, CV of diastolic BP (DBP) (1.08, 1.03–1.12; P = 0.001) over 24 h post stroke was significantly associated with 3-month poor outcome. The association was more apparent in sitting-up position (1.12, 1.06–1.19) compared with lying-flat position (1.03, 0.98–1.09) (P interaction = 0.005). BPV was associated with adverse stroke outcome, and the magnitude of the association was greater with sitting-up head positioning in terms of DBP variability.
Cluster-randomized, crossover trial of head positioning in acute stroke
(Massachusetts Medical Society, 2017) Anderson, C.S.; Arima, H.; Lavados, P.; Billot, L.; Hackett, M.L.; Olavarría, V.V; Muñoz Venturelli, P.; Brunser, A.; Peng, B.; Cui, L.; Song, L.; Rogers, K.; Middleton, S.; Lim, J.Y.; Forshaw, D.; Lightbody, C.E.; Woodward, M.; Pontes-Neto, O.; de Silva, H.A.; Lin, R.T.; Lee, T.H.; Pandian, J.D.; Mead, G.E.; Robinson, T.; Watkins, C.; Headpost Investigators and Coordinators
BACKGROUND: The role of supine positioning after acute stroke in improving cerebral blood flow and the countervailing risk of aspiration pneumonia have led to variation in head positioning in clinical practice. We wanted to determine whether outcomes in patients with acute ischemic stroke could be improved by positioning the patient to be lying flat (i.e., fully supine with the back horizontal and the face upwards) during treatment to increase cerebral perfusion. METHODS: In a pragmatic, cluster-randomized, crossover trial conducted in nine countries, we assigned 11,093 patients with acute stroke (85% of the strokes were ischemic) to receive care in either a lying-flat position or a sitting-up position with the head elevated to at least 30 degrees, according to the randomization assignment of the hospital to which they were admitted; the designated position was initiated soon after hospital admission and was maintained for 24 hours. The primary outcome was degree of disability at 90 days, as assessed with the use of the modified Rankin scale (scores range from 0 to 6, with higher scores indicating greater disability and a score of 6 indicating death). RESULTS: The median interval between the onset of stroke symptoms and the initiation of the assigned position was 14 hours (interquartile range, 5 to 35). Patients in the lying-flat group were less likely than patients in the sitting-up group to maintain the position for 24 hours (87% vs. 95%, P<0.001). In a proportional-odds model, there was no significant shift in the distribution of 90-day disability outcomes on the global modified Rankin scale between patients in the lying-flat group and patients in the sitting-up group (unadjusted odds ratio for a difference in the distribution of scores on the modified Rankin scale in the lying-flat group, 1.01; 95% confidence interval, 0.92 to 1.10; P=0.84). Mortality within 90 days was 7.3% among the patients in the lying-flat group and 7.4% among the patients in the sitting-up group (P=0.83). There were no significant between-group differences in the rates of serious adverse events, including pneumonia. CONCLUSIONS: Disability outcomes after acute stroke did not differ significantly between patients assigned to a lying-flat position for 24 hours and patients assigned to a sitting-up position with the head elevated to at least 30 degrees for 24 hours. (Funded by the National Health and Medical Research Council of Australia; HeadPoST ClinicalTrials.gov number, NCT02162017 .).
Regional variation in acute stroke care organisation
(Elsevier, 2016) Muñoz Venturelli, P.; Robinson, T.; Lavados, P.M.; Olavarría, V.V.; Arima, H.; Billot, L.; Hackett, M.L.; Lim, J.Y.; Middleton, S.; Pontes-Neto, O.; Peng, B.; Cui, L.; Song, L.; Mead, G.; Watkins, C.; Lin, R.T.; Lee, T.H.; Pandian, J.; de Silva, H.A.; Anderson, C.S.; HeadPoST Investigators
BACKGROUND: Few studies have assessed regional variation in the organisation of stroke services, particularly health care resourcing, presence of protocols and discharge planning. Our aim was to compare stroke care organisation within middle- (MIC) and high-income country (HIC) hospitals participating in the Head Position in Stroke Trial (HeadPoST). METHODS: HeadPoST is an on-going international multicenter crossover cluster-randomized trial of 'sitting-up' versus 'lying-flat' head positioning in acute stroke. As part of the start-up phase, one stroke care organisation questionnaire was completed at each hospital. The World Bank gross national income per capita criteria were used for classification. RESULTS: 94 hospitals from 9 countries completed the questionnaire, 51 corresponding to MIC and 43 to HIC. Most participating hospitals had a dedicated stroke care unit/ward, with access to diagnostic services and expert stroke physicians, and offering intravenous thrombolysis. There was no difference for the presence of a dedicated multidisciplinary stroke team, although greater access to a broad spectrum of rehabilitation therapists in HIC compared to MIC hospitals was observed. Significantly more patients arrived within a 4-h window of symptoms onset in HIC hospitals (41 vs. 13%; P<0.001), and a significantly higher proportion of acute ischemic stroke patients received intravenous thrombolysis (10 vs. 5%; P=0.002) compared to MIC hospitals. CONCLUSIONS: Although all hospitals provided advanced care for people with stroke, differences were found in stroke care organisation and treatment. Future multilevel analyses aims to determine the influence of specific organisational factors on patient outcomes.