DSpace Repository :: Browsing by Author "Brunser, Alejandro"

Browsing by Author "Brunser, Alejandro"

Now showing 1 - 20 of 41

A Chilean Experience of Telestroke in a COVID-19 Pandemic Year
(2022) Delfino, Carlos; Mazzon, Enrico; Cavada, Gabriel; Muñoz Venturelli, Paula; Brunser, Alejandro; Jurado, Felipe; Lara, Lorena; Rocha, Diego; Arévalo, Mirya; Rojas, Diego; Mansilla, Eloy
Background and purpose: Telemedicine for stroke patients' care (telestroke [TS]) has grown notably in recent decades and may offer advantages during health crisis. Hospital admissions related to stroke have decreased globally during the COVID-19 pandemic, but scarce information is available regarding the effect of COVID-19 in TS. Using a population-based TS registry, we investigated the impact of the first year of the COVID-19 pandemic throughout our TS network in Santiago, Chile. Methods: Stroke codes evaluated after the onset of COVID-19 restrictions in Chile (defined as March 15, 2020) were compared with those evaluated in 2019. We analyzed differences between number of stroke codes, thrombolysis rate, stroke severity, and time from the stroke onset to hospital admission. Results: We observed that the number of stroke codes and the number of patients undergoing reperfusion therapy did not change significantly (p = 0.669 and 0.415, respectively). No differences were found with respect to the median time from the stroke onset to admission (p = 0.581) or in National Institutes of Health Stroke Scale (NIHSS) scores (p = 0.055). The decision-making-to-needle time was significantly shorter in the COVID-19 period (median 5 min [IQR 3-8], p < 0.016), but no significant changes were found at the other times. Conclusions: This study demonstrates the potential of adapting TS to extreme situations such as the COVID-19 pandemic, as well as the importance of establishing networks that facilitate patient access to quality treatments.
Accuracy of diffusion-weighted imaging in the diagnosis of stroke in patients with suspected cerebral infarct
(American Heart Association, 2013) Brunser, Alejandro; Hoppe, Arnold; Illanes, Sergio; Díaz, Violeta; Muñoz, Paula; Cárcamo, Daniel; Olavarría, Verónica; Valenzuela, Marcela; Lavados, Pablo
BACKGROUND AND PURPOSE: The accuracy of diffusion-weighted imaging (DWI) for the diagnosis of acute cerebral ischemia among patients with suspected ischemic stroke arriving to an emergency room has not been studied in depth. METHODS: DWI was performed in 712 patients with acute or subacute focal symptoms that suggested an acute ischemic stroke (AIS), 609 of them with AIS. RESULTS: DWI demonstrated a sensitivity of 90% and specificity of 97%, a positive likelihood ratio of 31 and a negative likelihood ratio of 0.1 for detecting AIS. The overall accuracy was 95%. Of those patients who demonstrated abnormal DWI studies, 99.5% were AIS patients, and of those patients with normal DWI studies 63% were stroke mimics. CONCLUSIONS: DWI is accurate in detecting AIS in unselected patients with suspected AIS; a negative study should alert for nonischemic conditions.
Accuracy of Power Mode TranscranialDoppler in the Diagnosis of Brain Death
(2015) Brunser, Alejandro; Lavados, Pablo; Cárcamo, Daniel; Hoppe, Arnold; Olavarría, Verónica; López, Javiera; Muñoz, Paula; Rivas, Rodrigo
Background:The diagnosis of brain death (BD) is complex. For this reason, we aimed toevaluate the accuracy of power mode transcranial Doppler (PMD-TCD) in diagnosing BD.Patients and methods:Patients admitted to an intensive care unit between December 2003and January 2012 were included in this study if they were in a structural coma, had nocraniectomy, and were evaluated blind by a neurologist using PMD-TCD. The diagnosis of BDwas based on an evaluation that took into consideration the absence of sedative drugs, amedian blood pressure>60 mmHg, a body temperature>35 C, and the absence of brainstemreflexes. A neurosonologist followed a protocol using PMD-TCD that considered the examina-tion as positive for brain circulatory arrest given the presence of reverberating, small systolicpeaks or the disappearance of a previous signal present in both middle cerebral arteries andintracranial vertebral arteries.Results:A total of 74 patients were evaluated. In 61 (82.4%) patients the interval betweenboth evaluations was less than 1 hour. The sensitivity and specificity for the diagnosis of BD with PMD-TCD were 100% and 98%, respectively. The positive and negative likelihood ratios forBD were 45 and 0, respectively.Conclusion:PMD-TCD is accurate for the diagnosis of BD.
Cervical artery dissection in postpartum women after cesarean and vaginal delivery
(2022) Urrutia, Francisca; Mazzon, Enrico; Brunser, Alejandro; Díaz, Violeta; Calderon, Juan; Stecher, Ximena; Bernstein, Tomas; Zuñiga, Paulo; Schilling, Andrea; Muñoz, Paula
Background and aims: Cervical artery dissection (CAD) is an infrequent but potentially disabling and fatal disease, accounting for up to 25 % of strokes in young adults. Pregnancy-related hormonal changes and increased hemodynamic stress on artery walls during vaginal delivery have been associated to CAD. We aim to describe a series of women presenting CAD during postpartum (PP) after cesarean and vaginal delivery. Methods: CAD women admitted to one hospital in Santiago, Chile, between July 2018 and October 2020 were included in a prospective cohort. Demographic, clinical and imaging data were registered for the PP group. Results: Sixty-seven women were diagnosed with CAD, from which 10 were PP. Seven women had cesarean section and 3 had vaginal delivery. They presented CAD related symptoms after a median of 10.5 (IQR 5-15) days from delivery. All of them had headache as initial symptom, 9 presented cervical pain and 8 had a family history of stroke. Four patients presented preeclampsia during pregnancy. Acute treatment consisted mostly in antiplatelet agents and analgesics. None of these patients had a CAD related stroke. Demographic, clinical and imaging characteristics of these women with CAD during PP are described. Conclusions: This case series underpins the importance of clinical suspicion of CAD after delivery, highlighting the fact that CAD is not limited to women with vaginal delivery, thus alternative causes beyond acute hemodynamic stress could be involved. Further research is required to determine genetic components, along with deeper knowledge of modulating factors related to CAD in this setting.
Cervical Artery Dissections with and without stroke, risk factors and prognosis: a Chilean prospective cohort
(2020) Mazzon, Enrico; Rocha, D.; Brunser, Alejandro; Barra, C. de la; Stecher, Ximena; Bernstein, T.; Zúñiga, P.; Díaz, V.; Martínez, G.; Muñoz Venturelli, Paula
We aimed to characterize spontaneous cervical artery dissection (CeAD) patients with and without stroke and describe risk factors for cerebrovascular complications in a Chilean prospective cohort. Methods: Consecutive CeAD patients admitted to a Chilean center confirmed by neuroimaging. Logistic regression was used. Results: 168 patients were included, median follow-up time was 157 days. Stroke occurred in 49 (29.2%) cases, 4 (2%) patients died, all of whom had a stroke, and 10 (6%) presented CeAD recurrence. In univariate analyses, men (odds ratio [OR] 3.97, 95% confidence interval [CI] 1.97-8.00, P < 0.001), internal carotid artery CeAD (OR 2.82, 95% CI 1.38-5.78, P = 0.005) and vessel occlusion (OR 4.45, 95% CI 1.38-14.38, P = 0.035) increased stroke risk. Conversely, vertebral artery dissection (OR 0.35, 95% CI 0.16-0.74, P = 0.006) and longer symptom onset to admission (O-A) time (OR 0.79, 95% CI 0.70-0.90, P < 0.001) were associated to decreased stroke risk. After multivariate analysis, men (OR 2.88, 95% CI 1.32-6.27, P = 0.008) and O-A time (OR 0.80, 95% CI 0.69-0.92, P = 0.002) remained independently associated with stroke. Conclusion: CeAD presented commonly as a non-stroke entity, with favorable prognosis. Albeit to a higher frequency of CeAD in women, stroke occurred predominantly in men, who were admitted earlier.
Cluster-Randomized, Crossover Trial of Head Positioning in Acute Stroke
(Massachusetts Medical Society, 2017) Anderson, Craig; Arima, Hisatomi; Lavados, Pablo; Billot, Laurent; Hackett, Maree; Olavarría, Verónica; Muñoz Venturelli, Paula; Brunser, Alejandro; Peng, Bin; Cui, Liying; Song, Lily; Rogers, Kris; Middleton, Sandy; Lim, Joyce Y.; Forshaw, Denise; Lightbody, Elizabeth; Woodward, Mark; Pontes-Neto, Octavio; De Silva, Asita; Lin, Ruey-Tay; Lee, Tsong-Hai; Pandian, Jeyaraj D.; Mead, Gillian E.; Robinson, Thompson; Watkins, Caroline; 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.)
Determinantes del tiempo puerta-aguja en trombolisis endovenosa en el infarto cerebral, experiencia de un centro
(2020) Brunser, Alejandro; Mazzon, Enrico; Muñoz, Paula; Hoppe, Arnold; Lavados, Pablo; Rojo, Alexis; Navia, Víctor; Cavada, Gabriel; Olavarría, Verónica; Mansilla, Eloy
Background: Intravenous thrombolysis (IT) in acute ischemic stroke (AIS) is time dependent. The time elapsed from hospital admission to the thrombolytic bolus is named door to needle time (DNT) and is recommend to be of less than 60 min. Aim: To describe the DNT in our center and determine those factors associated with a DNT longer than 60 min. Material and Methods: Prospective analysis of patients treated with IT at a private hospital between June 2016 and June 2019. The percentage of patients with DNT exceeding 60 min, and the causes for this delay were evaluated. Results: IT was used in 205 patients. DNT was 43.6 ± 23.8 min. Forty patients (19.5% (95% CI, 14.4-25.7), had a DNT longer than 60 min. Uni-varied analysis demonstrated that AIS with infratentorial symptomatology (ITS), was significantly associated with DNTs exceeding 60 min. A history of hypertension, a higher NIH Stroke Scale score, the presence of an hyperdense sign in brain tomography (p = 0.001) and the need for endovascular therapy (p = 0.019), were associated with DNT shorter than 60 min. Multivariate analysis ratified the relationship between ITS and DNT longer than 60 min (Odds ratio: 3.19, 95% confidence intervals 1.26-8). Conclusions: The individual elements that correlated with a DNT longer than 60 min were the failure to detect the AIS during triage and doubts about its diagnosis
Diffusion-weighted imaging as predictor of acute ischemic stroke etiology
(2021) Brunser, Alejandro; Mansilla, Eloy; Navia, Victor; Mazzon, Enrico; Rojo, Alexis; Cavada, Gabriel; Olavarría, Verónica; Muñoz Venturelli, Paula; Manuel, Pablo
Background: Topographic patterns may correlate with causes of ischemic stroke. Objective: To investigate the association between diffusionweighted imaging (DWI) and Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification. Methods: We included 1019 ischemic stroke patients. DWI were classified as: i) negative; ii) DWI single lesion (cortico-subcortical, cortical, subcortical ≥20 mm, or subcortical <20 mm); iii) scattered lesions in one territory (small scattered lesions or confluent with additional lesions); and iv) multiple lesions (multiple unilateral anterior circulation [MAC], multiple posterior circulation [MPC], multiple bilateral anterior circulation [MBAC], and multiple anterior and posterior circulations [MAP]). Results: There was a relationship between DWI patterns and TOAST classification (p<0.001). Large artery atherosclerosis was associated with small, scattered lesions in one vascular territory (Odds Ratio [OR] 4.22, 95% confidence interval [95%CI] 2.61–6.8), MPC (OR 3.52; 95%CI 1.54–8.03), and subcortical lesions <20 mm (OR 3.47; 95%CI 1.76–6.85). Cardioembolic strokes correlated with MAP (OR 4.3; 95%CI 1.64–11.2), cortico-subcortical lesions (OR 3.24; 95%CI 1.9–5.5) and negative DWI (OR 2.46; 95%CI 1.1–5.49). Cryptogenic strokes correlated with negative DWI (OR 4.1; 95%CI 1,84–8.69), cortical strokes (OR 3.3; 95%CI 1.25–8.8), MAP (OR 3.33; 95%CI 1.25–8.81) and subcortical lesion ≥20 mm (OR 2.44; 95%CI 1,04–5.73). Lacunar strokes correlated with subcortical lesions diameter <20 mm (OR 42.9; 95%CI 22.7–81.1) and negative DWI (OR 8.87; 95%CI 4.03–19.5). Finally, MBAC (OR 9.25; 95%CI 1.12–76.2), MAP(OR 5.54; 95%CI 1.94–15.1), and MPC (OR 3.61; 95%CI 1.5–8.7) correlated with stroke of other etiologies. Conclusions: A relationship exists between DWI and stroke subtype.
Exclusion criteria for intravenous thrombolysis in stroke mimics: an observational study
(Elsevier, 2013) Brunser, Alejandro; Illanes, Sergio; Lavados, Pablo; Muñoz, Paula; Carcamo, Daniel; Hoppe, Arnold; Olavarría, Verónica; Delgado, Iris; Diaz, Violeta
BACKGROUND: Stroke mimics (SMs) are frequent in emergency departments (EDs), but are treated infrequently with intravenous recombinant tissue plasminogen activator (rt-PA) thrombolysis. We aimed at identifying the factors that lead to the exclusion of SMs from thrombolytic therapy. METHODS: Consecutive patients presenting to the ED between December 2004 and March 2011 with symptoms that suggested acute ischemic stroke were included. RESULTS: Eight hundred forty-two patients were included in this study; 113 (13.4%) were considered SMs; these patients were younger (P = .01), more frequently diabetic (P = .001), arrived later to the ED (P = .03), had lower National Institutes of Health Stroke Scale scores (P < .001), and higher frequencies of negative diffusion-weighted imaging studies (P = .002). The most common causes of cases of SM were toxic metabolic disorders (n = 34 [30.1%]) and seizures (n = 22 [19.5%]). The most frequent cause of consultation was aphasia (n = 43 [37.6%]). SM patients had a total of 152 contraindications for rt-PA, with 34 (30%) patients having >1 contraindication. The most frequent of these were being beyond the therapeutic window for thrombolysis (n = 96) and having deficits not measurable by the National Institutes of Health Stroke Scale or very mild symptoms before the start of rt-PA (n = 37). Twenty-four (21.2%) patients had both contraindications simultaneously. Two patients (1.76%) in the SM group were candidates for rt-PA but did not receive this treatment because they or their family rejected it. Of 729 stroke patients, 87 (11.9%) did receive rt-PA. CONCLUSIONS: SM patients frequently had exclusion criteria for systemic thrombolysis, the most frequent being presenting beyond the established thrombolytic window.
Flat-head positioning increases cerebral blood flow in anterior circulation acute ischemic stroke. A cluster randomized phase IIb trial.
(Sage Publications, 11/09/2017) Olavarria, Veronica; Lavados, Pablo; Muñoz Venturelli, Paula; Gonzalez, Francisca; Gaete, Javier; Martins, Sheila; Arima, Hisatomi; Anderson, Craig; Brunser, Alejandro
Background Whether lying-flat improves blood flow in patients with acute ischemic stroke is unknown. Our aim was to investigate if lying-flat "changes" cerebral blood flow velocities assessed by transcranial Doppler in acute ischemic stroke patients. Methods In a multicenter cluster clinical trial, we randomly assigned patients within 12 h from onset of a neurological deficit due to cerebral ischemia of the anterior circulation to lying-flat or upright head positioning. The primary outcome was a change of 8 cm/s or more in mean cerebral blood flow velocities on transcranial Doppler to the middle cerebral artery at 1 and 24 h post-randomization, adjusted for imbalance in baseline variables. Secondary outcomes included serious adverse events and physical functioning at 90 days. Results Ninety-four of 304 patients screened were recruited. The primary outcome occurred in 11 (26%) of 43 patients in the lying-flat group and in 6 (12%) of 51 in the upright group at 1 h (adjusted odds ratio, 3.81; 95% CI, 1.07 to 13.54), and in 23 (53%) and 18 (36%) patients in these respective groups at 24 h (adjusted odds ratio, 3.04; 95% CI, 1.08 to 8.53). There were no between-group differences in serious adverse events, including pneumonia, heart failure or mortality, nor in functional outcome at 3 months (adjusted common odds ratio, 1.38; 95% CI 0.64 to 3.00). Conclusion The lying-flat head position was associated with a significant increase in cerebral blood flow velocities at one and 24 h within the ipsilateral hemisphere of anterior circulation acute ischemic stroke, without serious safety concerns. Clinical trial registration-URL: http://www.clinicaltrials.gov . Unique identifier: NCT01706094.
Head position and cerebral blood flow in acute ischemic stroke patients: protocol for the pilot phase, cluster randomized, Head Position in Acute Ischemic Stroke Trial (HeadPoST pilot)
(Sage Publications, 2016) Brunser, Alejandro; Muñoz Venturelli, Paula; Lavados, Pablo; Gaete, Javier; Martins, Sheila; Arima, Hisatomi; Anderson, Craig; Olavarría, Verónica
RATIONALE: Few proven interventions exist for acute ischemic stroke (AIS), and most are expensive and restricted in applicability. Lying flat 'head down' positioning of AIS patients has been shown to increase by as much as 20%, mean cerebral blood flow velocities (CBFV) measured by transcranial Doppler (TCD) but whether this translates into clinical improvement is uncertain. AIM: To determine if the lying flat position increases mean CBFV in the affected territory as compared to the sitting up position in AIS patients. METHODS AND DESIGN: Head Position in Acute Ischemic Stroke Trial (HeadPoST pilot) is a cluster randomized (clusters being months), assessor-blinded end-point, phase IIb trial, where consecutive adults with anterior circulation AIS within 12 h of symptom onset are positioned to a randomized position for 48 h with TCD performed serially. STUDY OUTCOMES: Primary outcome is mean CBFV on TCD at 1 and 24 h after positioning. Secondary outcomes include: serious adverse events, neurological impairment at seven days, and death and disability at 90 days. SAMPLE SIZE ESTIMATES: Assuming an increase of 8.3 (SD 11.4) cm/s in average of mean CBFV when tilted from 30° to 0°, 46 clusters are required (92 patients in total) to detect a 20% increase of mean CBFV with 90% power and 5% level of significance. CONCLUSION: HeadPoST pilot is a cluster randomized multicenter clinical trial investigating the effect of head positioning on mean CBFV in anterior circulation AIS.
Head position and cerebral blood flow velocity in acute ischemic stroke: a systematic review and meta-analysis.
(Karger, 2014) Lavados, Pablo; Heritier, Stephane; Muñoz Venturelli, Paula; Brunser, Alejandro; Anderson, Craig; Arima, Hisatomi; Olavarría, Verónica
BACKGROUND: Patients with acute ischemic stroke (AIS) have impaired vasomotor reactivity, especially in the affected cerebral hemisphere, such that they may depend directly on systemic blood pressure to maintain perfusion to vulnerable 'at risk' penumbral tissue. As the sitting up position may affect cerebral perfusion by decreasing cerebral blood flow (CBF) in salvageable tissue, positioning AIS patients with their head in a lying flat position could increase CBF through collateral circulation or gravitational force. We wished to quantify the effect of different head positions on mean flow velocity (MFV) by transcranial Doppler ultrasonography (TCD) in AIS patients to assess the potential for benefit (or harm) of head positioning in a clinical trial. METHODS: We performed a systematic review and meta-analysis of observational studies with TCD to evaluate differences in cerebral MFV between the lying flat and sitting up head positions in AIS. For each study and each comparison, we obtained the mean value of changes in MFV and its variance. RESULTS: A total of 303 studies were identified, but 298 were excluded for varying reasons; 4 papers met the inclusion criteria and 57 patients were included in the meta-analysis for calculation of the overall mean difference in MFV. We found a significant increase in MFV from a bed angle of 30 to 15° (4.6 cm/s, 95% confidence interval, CI, 2.9-6.2, p < 0.001) and from 30 to 0° (8.3 cm/s, 95% CI 5.3-11.3, p < 0.001) in the affected hemisphere but not on the normal side in AIS patients. CONCLUSIONS: In AIS patients, MFV increased significantly in the side affected by the stroke but not in the unaffected side when they were positioned in a lying flat head position at 0 or 15° compared to an upright head position at 30°. The clinical significance of these findings is now undergoing further randomized evaluation in the international multicenter Head Position in Acute Stroke Trial (HeadPoST).
Head Position in Stroke Trial (HeadPoST) - sitting-up vs lying-flat positioning of patients with acute stroke: study protocol for a cluster randomised controlled trial
(Biomed Central Ltd., 2015) Muñoz, Paula; Arima, Hisatomi; Lavados, Pablo; Brunser, Alejandro; Peng, Bin; Cui, Liying; Song, Lily; Billot, Laurent; Boaden, Elizabeth; Hackett, Maree; Heritier, Stephane; Stephen, Jan; Middleton, Sandy; Olavarría, Verónica; Lim, Joyce; Lyndle, Richard; Heeley, Emma; Thompson, Robinson; Pontes, Octavio; Natsagdorj, Lkhamtsoo; Ruey-Tay, Lin; Watkins, Caroline; Anderson, Craig
BACKGROUND: Positioning a patient lying-flat in the acute phase of ischaemic stroke may improve recovery and reduce disability, but such a possibility has not been formally tested in a randomised trial. We therefore initiated the Head Position in Stroke Trial (HeadPoST) to determine the effects of lying-flat (0°) compared with sitting-up (≥ 30°) head positioning in the first 24 hours of hospital admission for patients with acute stroke. METHODS/DESIGN: We plan to conduct an international, cluster randomised, crossover, open, blinded outcome-assessed clinical trial involving 140 study hospitals (clusters) with established acute stroke care programs. Each hospital will be randomly assigned to sequential policies of lying-flat (0°) or sitting-up (≥ 30°) head position as a 'business as usual' stroke care policy during the first 24 hours of admittance. Each hospital is required to recruit 60 consecutive patients with acute ischaemic stroke (AIS), and all patients with acute intracerebral haemorrhage (ICH) (an estimated average of 10), in the first randomised head position policy before crossing over to the second head position policy with a similar recruitment target. After collection of in-hospital clinical and management data and 7-day outcomes, central trained blinded assessors will conduct a telephone disability assessment with the modified Rankin Scale at 90 days. The primary outcome for analysis is a shift (defined as improvement) in death or disability on this scale. For a cluster size of 60 patients with AIS per intervention and with various assumptions including an intracluster correlation coefficient of 0.03, a sample size of 16,800 patients at 140 centres will provide 90 % power (α 0.05) to detect at least a 16 % relative improvement (shift) in an ordinal logistic regression analysis of the primary outcome. The treatment effect will also be assessed in all patients with ICH who are recruited during each treatment study period. DISCUSSION: HeadPoST is a large international clinical trial in which we will rigorously evaluate the effects of different head positioning in patients with acute stroke.
Head Position in the Early Phase of Acute Ischemic Stroke: An International Survey of Current Practice
(National Stroke Association. Published by Elsevier Inc., 2015) Muñoz, Paula; Olavarría, Verónica; González, Francisca; Brunser, Alejandro; Lavados, Pablo; Arima, Hisatomi; Anderson, Craig
BACKGROUND: Evidence to recommend a specific head position for patients in the early phase of acute ischemic stroke (AIS) is scarce. The aim of this study was to assess current head position practice for AIS patients among physicians from hospitals in different countries. METHODS: A cross-sectional survey research design was used; physicians who are part of a stroke research network were invited to participate by e-mail. Descriptive statistics were used. RESULTS: An invitation to participate was delivered to 298 doctors from 16 countries and 42.9% completed all survey questions. Participant responses were evenly divided in sitting up and lying flat position as the most usual at their hospital: 52.8% (95% confidence interval [CI], 43.7-61.0) of respondents preferred sitting up, whereas 47.2% (95% CI, 38.2-55.5) preferred lying flat; 53.9% (95% CI, 45.3-62.5) of participants answered that no written protocol specifying the indicated head position for stroke patients was available at their hospital or department, and 71% (95% CI, 63.2-78.9) recognized being uncertain about the best position for AIS patients. CONCLUSIONS: Common practice differs between physicians, and there is a lack of consensus about the best strategy regarding head position for AIS patients in many countries. An opportunity exists for a randomized trial to resolve this uncertainty and develop evidence-based consensus protocols to improve patient management and outcomes.
Impact of Evidence-Based Stroke Care on Patient Outcomes: A Multilevel Analysis of an International study
(2019) Muñoz Venturelli, Paula; Li, Xian; Middleton, Sandy; Watkins, Caroline; Lavados, Pablo; Olavarría, Verónica; Brunser, Alejandro; Pontes-Neto, Octavio; Santos, Taiza; Hisatomi, Arima; Billot, Laurent; Hackett, Maree; Song, Lily; Robinson, Thompson; Anderson, Craig; HEADPOST, Head positioning in acute
Background-—The uptake of proven stroke treatments varies widely. We aimed to determine the association of evidence-based processes of care for acute ischemic stroke (AIS) and clinical outcome of patients who participated in the HEADPOST (Head Positioning in Acute Stroke Trial), a multicenter cluster crossover trial of lying flat versus sitting up, head positioning in acute stroke. Methods and Results-—Use of 8 AIS processes of care were considered: reperfusion therapy in eligible patients; acute stroke unit care; antihypertensive, antiplatelet, statin, and anticoagulation for atrial fibrillation; dysphagia assessment; and physiotherapist review. Hierarchical, mixed, logistic regression models were performed to determine associations with good outcome (modified Rankin Scale scores 0–2) at 90 days, adjusted for patient and hospital variables. Among 9485 patients with AIS, implementation of all processes of care in eligible patients, or “defect-free” care, was associated with improved outcome (odds ratio, 1.40; 95% CI, 1.18–1.65) and better survival (odds ratio, 2.23; 95% CI, 1.62–3.09). Defect-free stroke care was also significantly associated with excellent outcome (modified Rankin Scale score 0–1) (odds ratio, 1.22; 95% CI, 1.04–1.43). No hospital characteristic was independently predictive of outcome. Only 1445 (15%) of eligible patients with AIS received all processes of care, with significant regional variations in overall and individual rates. Conclusions-—Use of evidence-based care is associated with improved clinical outcome in AIS. Strategies are required to address regional variation in the use of proven AIS treatments.
In-Hospital Acute Ischemic Stroke is Associated with Worse Outcome: Experience of a Single Center in Santiago Chile
(2021) Brunser, Alejandro; Navia, Víctor; Araneda, Patricia; Mazzon, Enrico; Muñoz Venturelli, Paula; Cavada, Gabriel; Olavarría, Verónica; Lavados, Pablo
Objectives: In-hospital acute ischemic stroke (HIS) accounts for 217% of all acute ischemic strokes (AIS) seen in hospital and they have worse prognosis. In this study we aimed to identify the frequency of HIS and their characteristics in our center. Materials and Methods: Retrospective analysis of a prospective register of patients with AIS seen at Clínica Alemana de Santiago, between January 2017 and January 2019. HIS and community onset ischemic strokes patients (CIS) were compared, univariate analysis was performed, covariates with p < 0.25 were selected for multivariate analysis. Differences between, proportion of strokes treated with thrombolytic therapy, door to needle time were compared between HIS and CIS patients, as also mortality rates at 90 days. Results: During the study period 369 patients with AIS were seen; of these 20 (5.4%, 95 CI%, 3.58.2) corresponded to HIS. In univariate analysis, HIS compared to patients arriving form the community to the emergency room, suffered more frequently from, heart failure (p = 0.04), and active malignancies (p < 0.001). HIS patients had longer times from symptom onset to non-contrast brain tomography (540 §150 minutes); they were also less frequently treated with intravenous thrombolysis compared to community AIS: 15% versus 30% respectively (p = 0.08). Mortality rates at 90 days were higher in HIS: 30 versus 5% (p = 0.001). Conclusions: In this cohort, HIS patients suffered delays in their neuroimaging studies and received less intravenous thrombolysis; this underscores the need for a standardized approach to the recognition and management of inhospital acute ischemic stroke
Influence of Including Patients with Premorbid Disability in Acute Stroke Trials: The HeadPoST Experience
(2021) Wang, Xia; Moullaali, Tom J.; Ouyang, Menglu; Billot, Laurent; Sandset, Else Charlotte; Song, Lili; Delcourt, Candice; Hackett, Maree L.; Watkins, Caroline L.; Robinson, Thompson G.; Yang, Jie; Lavados, Pablo; Brunser, Alejandro; Muñoz Venturelli, Paula; Olavarría, Verónica; Arima, Hisatomi; Middleton, Sandy; Pontes-Neto, Octávio M.; Pandian, Jeyaraj Durai; Rogers; Rogers, Kris; Anderson, Craig S.
Background: Patients with premorbid functional impairment are generally excluded from acute stroke trials. We aimed to determine the impact of including such patients in the Head Positioning in acute Stroke Trial (HeadPoST) and early additional impairment on outcomes. Methods: Post hoc analyses of HeadPoST, an international, cluster-randomized crossover trial of lying-flat versus sitting-up head positioning in acute stroke. Associations of early additional impairment, defined as change in modified Rankin scale (mRS) scores from premorbid levels (estimated at baseline) to Day 7 ("early ΔmRS"), and poor outcome (mRS score 3-6) at Day 90 were determined with generalized linear mixed model. Heterogeneity of the trial treatment effect was tested according to premorbid mRS scores 0-1 versus 2-5. Results: Of 8,285 patients (38.9% female, mean age 68 ± 13 years) with complete data, there were 1,984 (23.9%) with premorbid functional impairment (mRS 2-5). A significant linear association was evident for early ∆mRS and poor outcome (per 1-point increase in ΔmRS, adjusted odds ratio 1.20, 95% confidence interval 1.14-1.27; p < 0.0001). Patients with greater premorbid functional impairment were less likely to develop additional impairment, but their risk of poor 90-day outcome significantly increased with increasing (worse) premorbid mRS scores (linear trend p < 0.0001). There was no heterogeneity of the trial treatment effect by level of premorbid function. Conclusions: Early poststroke functional impairment that exceeded premorbid levels was associated with worse 90-day outcome, and this association increased with greater premorbid functional impairment. Yet, including premorbid impaired patients in the HeadPoST did not materially affect the subsequent treatment effect.
Intraventricular Bleeding and Hematoma Size as Predictors of Infection Development in Intracerebral Hemorrhage: A Prospective Cohort Study
(Elsevier, 2016) Vial Undurraga, Felipe; Brunser, Alejandro; Lavados, Pablo; Illanes, Sergio
BACKGROUND: Acute intracerebral hemorrhage (ICH) is associated with increased susceptibility to bacterial infection. The physiopathology of this phenomenon is not very clear. We conducted a prospective observational study investigating the correlation and independent predictors of infections in patients with ICH. PATIENTS AND METHODS: Patients admitted between April 1997 and June 2013 with ICH diagnosis were evaluated for inclusion and exclusion criteria. RESULTS: Two hundred twenty-two patients were included in this study. Ninety four patients (42.6%) presented with an infection during hospitalization being more common than pneumonia (30%) and urinary tract infections (14%). Intraventricular hemorrhage (IVH) (95% confidence interval [CI], 62.7% versus 39.3%; P < .001) and higher ICH score (95% CI, 2.31% versus 1.67%; P = .0014) were more common in patients who had infections. We found the following risk factors for having an infection in patients with ICH: IVH (odds ratio [OR] 2.3; 95% IC, 1.3-4.1), each point of ICH score (OR 1.3; 95% CI, 1.1-1.6), and having a hematoma volume larger than 30 cc (OR 2.0; 95% CI, 1.1-3.5). The localization of the hematoma was not found to be relevant. CONCLUSIONS: ICH score, size of the hematoma, and presence of IVH are independent risk factors for having an infection after ICH.
Low blood pressure and adverse outcomes in acute stroke: HeadPoSTstudy explanations
(2021) Muñoz Venturelli, Paula; Billota, Laurent; Wang, Xia; Ouyang, Menglu; Song, Lili; Arima, Hisatomi; Lavados, Pablo; Hackett, Maree L.; Olavarría, Verónica V.; Brunser, Alejandro; Middleton, Sandy; Pontes-Neto, Octavio M.; Lee, Tsong-Hai; Watkins, Caroline L.; Robinson, Thompson; Anderson, Craig S.
Objective: As uncertainties exist over underlying causes, we aimed to define the characteristics and prognostic significance of low blood pressure (BP) early after the onset of acute stroke. Methods: Post hoc analyzes of the international Head Positioning in acute Stroke Trial (HeadPoST), a pragmatic cluster-crossover randomized trial of lying flat versus sitting up in stroke patients from nine countries during 2015-2016. Associations of baseline BP and death or dependency [modified Rankin scale (mRS) scores 3-6] and serious adverse events (SAEs) at 90 days were assessed in generalized linear mixed models with adjustment for multiple confounders. SBP and DBP was analysed as continuous measures fitted with a cubic spline, and as categorical measures with low (<10th percentile) and high (≥140 and ≥90 mmHg, respectively) levels compared with a normal range (≥10th percentile; 120-139 and 70-89 mmHg, respectively). Results: Among 11 083 patients (mean age 68 years, 39.9% women) with baseline BP values, 7.2 and 11.7% had low SBP (<120 mmHg) and DBP (<70 mmHg), respectively. Patients with low SBP were more likely to have preexisting cardiac and ischemic stroke and functional impairment, and to present earlier with more severe neurological impairment than other patients. Nonlinear 'J-shaped' relationships of BP and poor outcome were apparent: compared with normal SBP, those with low SBP had worse functional outcome (adjusted odds ratio 1.27, 95% confidence interval 1.02-1.58) and more SAEs, particularly cardiac events, with adjustment for potential confounders to minimize reverse causation. The findings were consistent for DBP and were stronger for ischemic rather than hemorrhagic stroke. Conclusion: The prognostic significance of low BP on poor outcomes in acute stroke was not explained by reverse causality from preexisting cardiovascular disease, and propensity towards greater neurological deficits and cardiac events. These findings provide support for the hypothesis that low BP exacerbates cardiac and cerebral ischemia in acute ischemic stroke.
Low dosis of alteplase, for ischemic stroke after Enchanted and its determinants, a single center experience
(2020) Brunser, Alejandro; Mazzon, Enrico; Cavada, Gabriel; Mansilla, Eloy; Rojo, Alexis; Almeida, Juan; Olavarría, Verónica; Muñoz Venturelli, Paula; Lavados, Pablo
Background: Low-dose alteplase (LrtPA) has been shown not to be inferior to the standard-dose (SrtPA) with respect to death/disability. Objective: We aim to evaluate the percentage of patients treated with LrtPA at our center after the ENCHANTED trial and the factors associated with the use of this dosage. Methods: Prospective study in consecutive patients with an acute stroke admitted between June 2016 and November 2018. Results: 160 patients were treated with intravenous thrombolysis, 50% female; mean age 65.4±18.5 years. Of these, 48 patients (30%) received LrtPA. In univariate analysis, LrtPA was associated with patient’s age (p=0.000), previous modified Rankin scale scores (mRS) (p<0.000), hypertension (p=0.076), diabetes mellitus (p=0.021), hypercholesterolemia (p=0.19), smoking (p=0.06), atrial fibrillation (p=0.10), history of coronary artery disease (p=0.06), previous treatment with antiplatelet agents (p<0.000), admission International Normalized Ratio-INR (p=0.18), platelet count (p=0.045), leukoaraiosis on neuroimaging (p<0.003), contraindications for thrombolytic treatment (p=0.000) and endovascular treatment (p=0.027). Previous relevant bleedings were determinants for treatment with LrtPA. Final diagnosis on discharge of stroke mimic was significant (p=0.02) for treatment with SrtPA. In multivariate analysis, mRS (OR: 2.21; 95%CI 1.37–14.19), previous antiplatelet therapy (OR: 11.41; 95%CI 3.98–32.70), contraindications for thrombolysis (OR: 56.10; 95%CI 8.81–357.80), leukoaraiosis (OR: 4.41; 95%CI 1.37–14.10) and diagnosis of SM (OR: 0.22; 95%CI 0.10–0.40) remained independently associated. Conclusions: Following the ENCHANTED trial, LrtPA was restricted to 30% of our patients. The criteria that clinicians apply are based mostly on clinical variables that may increase the risk of brain or systemic hemorrhage or exclude the patient from treatment with lytic drugs.

Browsing by Author "Brunser, Alejandro"

Results Per Page

Sort Options