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Dive into the research topics where Christopher Lewandowski is active.

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Featured researches published by Christopher Lewandowski.


The Lancet | 2004

Association of outcome with early stroke treatment: pooled analysis of ATLANTIS, ECASS, and NINDS rt-PA stroke trials.

Werner Hacke; Geoffrey A. Donnan; C. Fieschi; Markku Kaste; von Kummer R; Joseph P. Broderick; Thomas G. Brott; Michael R. Frankel; James C. Grotta; Haley Ec; Thomas Kwiatkowski; Levine; Christopher Lewandowski; Mei Lu; Patrick D. Lyden; Marler; Sheila K. Patel; Barbara Tilley; Gregory W. Albers; Erich Bluhmki; Wilhelm M; Scott Hamilton; Atlantis Trials Investigators; Ecass Trials Investigators

BACKGROUND: Quick administration of intravenous recombinant tissue plasminogen activator (rt-PA) after stroke improved outcomes in previous trials. We aimed to analyse combined data for individual patients to confirm the importance of rapid treatment. METHODS: We pooled common data elements from six randomised placebo-controlled trials of intravenous rt-PA. Using multivariable logistic regression we assessed the relation of the interval from stroke onset to start of treatment (OTT) on favourable 3-month outcome and on the occurrence of clinically relevant parenchymal haemorrhage. FINDINGS: Treatment was started within 360 min of onset of stroke in 2775 patients randomly allocated to rt-PA or placebo. Median age was 68 years, median baseline National Institute of Health Stroke Scale (NIHSS) 11, and median OTT 243 min. Odds of a favourable 3-month outcome increased as OTT decreased (p=0.005). Odds were 2.8 (95% CI 1.8-4.5) for 0-90 min, 1.6 (1.1-2.2) for 91-180 min, 1.4 (1.1-1.9) for 181-270 min, and 1.2 (0.9-1.5) for 271-360 min in favour of the rt-PA group. The hazard ratio for death adjusted for baseline NIHSS was not different from 1.0 for the 0-90, 91-180, and 181-270 min intervals; for 271-360 min it was 1.45 (1.02-2.07). Haemorrhage was seen in 82 (5.9%) rt-PA patients and 15 (1.1%) controls (p<0.0001). Haemorrhage was not associated with OTT but was with rt-PA treatment (p=0.0001) and age (p=0.0002). INTERPRETATION: The sooner that rt-PA is given to stroke patients, the greater the benefit, especially if started within 90 min. Our results suggest a potential benefit beyond 3 h, but this potential might come with some risks.


Neurology | 2000

Early stroke treatment associated with better outcome The NINDS rt-PA Stroke Study

John R. Marler; Barbara Tilley; Mei Lu; Thomas G. Brott; P.C. Lyden; James C. Grotta; Joseph P. Broderick; Steven R. Levine; M.P. Frankel; Steven H. Horowitz; Haley Ec; Christopher Lewandowski; T.P. Kwiatkowski

Background The National Institute of Neurological Disorders and Stroke (NINDS) rt-PA Stroke Study showed a similar percentage of intracranial hemorrhage and good outcome in patients 3 months after stroke treatment given 0 to 90 minutes and 91 to 180 minutes after stroke onset. At 24 hours after stroke onset more patients treated 0 to 90 compared to 91 to 180 minutes after stroke onset had improved by four or more points on the NIH Stroke Scale (NIHSS). The authors performed further analyses to characterize the relationship of onset-to-treatment time (OTT) to outcome at 3 months, early improvement at 24 hours, and intracranial hemorrhage within 36 hours. Methods Univariate analyses identified potentially confounding variables associated with OTT that could mask an OTT–treatment interaction. Tests for OTT–treatment interactions adjusting for potential masking confounders were performed. An OTT–treatment interaction was considered significant if p ≤ 0.10, implying that treatment effectiveness was related to OTT. Results For 24-hour improvement, there were no masking confounders identified and there was an OTT–treatment interaction (p = 0.08). For 3-month favorable outcome, the NIHSS met criteria for a masking confounder. After adjusting for NIHSS as a covariate, an OTT–treatment interaction was detected (p = 0.09): the adjusted OR (95% CI) for a favorable 3-month outcome associated with recombinant tissue-type plasminogen activator (rt-PA) was 2.11 (1.33 to 3.35) in the 0 to 90 minute stratum and 1.69 (1.09 to 2.62) in the 91 to 180 minute stratum. In the group treated with rt-PA, after adjusting for baseline NIHSS, an effect of OTT on the occurrence of intracranial hemorrhage was not detected. Conclusions If the NINDS rt-PA Stroke Trial treatment protocol is followed, this analysis suggests that patients treated 0 to 90 minutes from stroke onset with rt-PA have an increased odds of improvement at 24 hours and favorable 3-month outcome compared to patients treated later than 90 minutes. No effect of OTT on intracranial hemorrhage was detected within the group treated with rt-PA, possibly due to low power.


Stroke | 1999

Combined Intravenous and Intra-Arterial r-TPA Versus Intra-Arterial Therapy of Acute Ischemic Stroke: Emergency Management of Stroke (EMS) Bridging Trial

Christopher Lewandowski; Michael R. Frankel; Thomas A. Tomsick; Joseph P. Broderick; James L. Frey; Wayne M. Clark; Sidney Starkman; James C. Grotta; Judith Spilker; Jane Khoury; Thomas G. Brott

BACKGROUND AND PURPOSE The purpose of this study was to test the feasibility, efficacy, and safety of combined intravenous (IV) and local intra-arterial (IA) recombinant tissue plasminogen activator (r-TPA) therapy for stroke within 3 hours of onset of symptoms. METHODS This was a double-blind, randomized, placebo-controlled multi-center Phase I study of IV r-TPA or IV placebo followed by immediate cerebral arteriography and local IA administration of r-TPA by means of a microcatheter. Treatment activity was assessed by improvement on the National Institutes of Health Stroke Scale Score (NIHSSS) at 7 to 10 days. The Barthel Index, modified Rankin Scale, and the Glasgow Outcome Scale measured 3-month functional outcome. Arterial recanalization rates and their relation to total r-TPA dose and time to lysis were measured. Rates of life-threatening bleeding, intracerebral hemorrhage (ICH), or other bleeding complications assessed safety. RESULTS Thirty-five patients were randomly assigned, 17 into the IV/IA group and 18 into the placebo/IA group. There was no difference in the 7- to 10-day or the 3-month outcomes, although there were more deaths in the IV/IA group. Clot was found in 22 of 34 patients. Recanalization was better (P=0. 03) in the IV/IA group with TIMI 3 flow in 6 of 11 IV/IA patients versus 1 of 10 placebo/IA patients and correlated to the total dose of r-TPA (P=0.05). There was no difference in the median treatment intervals from time of onset to IV treatment (2.6 vs 2.7 hours), arteriography (3.3 vs 3.0 hours), or clot lysis (6.3 vs 5.7 hours) between the IV/IA and placebo/IA groups, respectively. A direct relation between NIHSSS and the likelihood of the presence of a clot was identified. Eight ICHs occurred; all were hemorrhagic infarctions. There were no parenchymal hematomas. Symptomatic ICH within 24 hours occurred in 1 placebo/IA patient only. Beyond 24 hours, symptomatic ICH occurred in 2 IV/IA patients only. Life-threatening bleeding complications occurred in 2 patients, both in the IV/IA group. Moderate to severe bleeding complications occurred in 2 IV/IA patients and 1 placebo/IA patient. CONCLUSIONS This pilot study demonstrates combined IV/IA treatment is feasible and provides better recanalization, although it was not associated with improved clinical outcomes. The presence of thrombus on initial arteriography was directly related to the baseline NIHSSS. This approach is technically feasible. The numbers of symptomatic ICH were similar between the 2 groups, which suggests that this approach may be safe. Further study is needed to determine the safety and effectiveness of this new method of treatment. Such studies should address not only efficacy and safety but also the cost-benefit ratio and quality of life, given the major investment in time, personnel, and equipment required by combined IV and IA techniques.


The New England Journal of Medicine | 1999

Effects of tissue plasminogen activator for acute ischemic stroke at one year

Thomas Kwiatkowski; Richard Libman; Michael R. Frankel; Barbara C. Tilley; Lewis B. Morgenstern; Mei Lu; Joseph P. Broderick; Christopher Lewandowski; John R. Marler; Steven R. Levine; Thomas G. Brott

Background In 1995, the two-part National Institute of Neurological Disorders and Stroke (NINDS) Recombinant Tissue Plasminogen Activator Stroke Study found that patients who were treated with tissue plasminogen activator (t-PA) within three hours after the onset of symptoms of acute ischemic stroke were at least 30 percent more likely than patients given placebo to have minimal or no disability three months after the stroke. It was unknown, however, whether the benefit would be sustained for longer periods. Methods In the NINDS trial, a total of 624 patients with stroke were randomly assigned to receive either t-PA or placebo. We collected outcome data over a period of 12 months after the occurrence of stroke. The primary outcome measure was a “favorable outcome,” defined as minimal or no disability as measured by the Barthel index, the modified Rankin Scale, and the Glasgow Outcome Scale. We assessed the treatment effect using a global statistic. Results Using an intention-to-treat analysis for the comb...


Stroke | 1998

Hypertension and Its Treatment in the NINDS rt-PA Stroke Trial

Thomas Brott; Mei Lu; Rashmi Kothari; Susan C. Fagan; Michael R. Frankel; James C. Grotta; Joseph P. Broderick; Thomas Kwiatkowski; Christopher Lewandowski; E. Clarke Haley; John R. Marler; Barbara C. Tilley

BACKGROUND AND PURPOSE We examined the frequency, course, and treatment of hypertension in the NINDS rt-PA Stroke Trial. METHODS Blood pressure (BP) was measured at the time of admission, at randomization, and then 36 times during the first 24 hours after randomization. Patients with a systolic BP of >185 mm Hg and a diastolic BP of >110 mm Hg at admission were defined as hypertensive before randomization, and those with a systolic BP of >180 mm Hg or a diastolic BP of >105 mm Hg within the first 24 hours after randomization were defined as hypertensive after randomization. Standardized clinical assessments were conducted at 24 hours and at 3 months. Post hoc analyses were conducted to evaluate the association of antihypertensive therapy with clinical outcomes. RESULTS Of the 624 patients, 121(19%) had hypertension on admission and 372 (60%) had hypertension in the 24 hours after randomization. The use of antihypertensive therapy before randomization (tPA 9%, placebo 9%) and after randomization (tPA 24%, placebo 29%) was similar between placebo- and tPA-treated patients. No adverse effects of prerandomization antihypertensive therapy on 3-month favorable outcome were detected for either the placebo- or tPA-treated groups. For placebo patients with hypertension in the 24 hours after randomization, clinical outcome measures were similar for those patients who did and did not receive antihypertensive therapy after randomization (P > or = 0.26); antihypertensive therapy was not associated with declines in BP (P = 0.44) or with abrupt declines (P = 0.14). Those tPA patients who were hypertensive after randomization and received antihypertensive therapy were less likely to have a favorable outcome at 3 months (P < 0.01) than those who were hypertensive and did not receive antihypertensive therapy. CONCLUSIONS The frequency of hypertension and the use of antihypertensive therapy were similar between the tPA and placebo groups in the NINDS rt-PA Stroke Trial. In the placebo group, antihypertensive therapy was not associated with less favorable outcomes at 3 months; postrandomization antihypertensive therapy was associated with less favorable outcomes for the tPA patients who were hypertensive. However, because of the nonrandomized use of antihypertensive therapy and the many post hoc comparisons leading to type 1 errors, the significance of this observation is unclear. Careful attention to BP and gentle management remain warranted for stroke patients treated with tPA.


Critical Care Medicine | 1995

A technique revisited: Hemodynamic comparison of closed- and open-chest cardiac massage during human cardiopulmonary resuscitation

Michael E. Boczar; M. A. Howard; Emanuel P. Rivers; Gerard B. Martin; Horst Hm; Christopher Lewandowski; Michael C. Tomlanovich; Richard M. Nowak

OBJECTIVE To compare the hemodynamics of closed-chest cardiac massage vs. open-chest cardiac massage in patients resuscitated from cardiac arrest that occurred outside of the hospital. DESIGN Prospective, non-outcome, case series. SETTING Large urban emergency department. PATIENTS Ten adult, normothermic, nontraumatic, out-of-hospital, cardiac arrest patients who failed advanced cardiac life support (ACLS) therapy. INTERVENTIONS Patients presenting to the hospital in cardiac arrest were managed according to the ACLS protocol at the clinicians discretion. Proximal aortic and central venous pressure catheters were placed to measure arteriovenous compression- and relaxation-phase pressure gradients. After 5 mins of baseline measurements during closed-chest cardiac massage, patients underwent a left lateral thoracotomy, and open-chest cardiac massage was performed for 5 mins. MEASUREMENTS AND MAIN RESULTS The mean coronary perfusion pressure and compression-phase pressure gradients were 7.3 +/- 5.7 and 6.2 +/- 5.4 mm Hg, respectively, during closed-chest cardiac massage, while increasing to 32.6 +/- 17.8 and 32.6 +/- 29.9 mm Hg, respectively, during open-chest cardiac massage. The differences between both measurements were statistically significant (p < .05). CONCLUSIONS Open-chest cardiac massage is superior to closed-chest cardiac massage in providing relaxation-phase and compression-phase pressure gradients during cardiac arrest in patients failing current ACLS protocols. During open-chest cardiac massage, all patients exceeded the minimum coronary perfusion pressure of 15 mm Hg, which is recommended to obtain a return of spontaneous circulation. Further outcome studies are needed to determine the timeliness and appropriate indications for open-chest cardiac massage.


Epilepsia | 2015

Intramuscular midazolam versus intravenous lorazepam for the prehospital treatment of status epilepticus in the pediatric population

Robert D. Welch; Katherine S. Nicholas; Valerie Durkalski-Mauldin; Daniel H. Lowenstein; Robin Conwit; Prashant Mahajan; Christopher Lewandowski; Robert Silbergleit

To examine the effectiveness of intramuscular (IM) midazolam versus intravenous (IV) lorazepam for the treatment of pediatric patients with status epilepticus (SE) in the prehospital care setting.


Journal of Stroke & Cerebrovascular Diseases | 2009

Sildenafil Treatment of Subacute Ischemic Stroke: A Safety Study at 25-mg Daily for 2 Weeks

Brian Silver; Sharon McCarthy; Mei Lu; Panayiotis Mitsias; Andrew Russman; Angelos M. Katramados; Daniel C. Morris; Christopher Lewandowski; Michael Chopp

BACKGROUND In several animal studies of young and aged rats with ischemic stroke, treatment with sildenafil improved functional outcomes compared with placebo. We conducted a safety study of sildenafil (25 mg daily for 2 weeks) shortly after ischemic stroke onset. METHODS We recruited patients aged 18 to 80 years with ischemic stroke, National Institutes of Health stroke scale (NIHSS) score 2 to 21, between days 2 and 9 after symptom onset. Patients were treated with sildenafil for 2 weeks (25 mg daily). The primary outcome measure was the adverse occurrence of any of the following during the treatment period: stroke worsening, new stroke, myocardial infarction, vision loss, hearing loss, or death from any cause. Secondary outcome measures were NIHSS score, Barthel indices, and modified Rankin score at 90 days. RESULTS Twelve patients were recruited. Mean age was 57 years, 5 were female, and median NIHSS score at entry was 9.5 (range 2-20). The primary outcome measure occurred in one patient (sudden death). Another patient committed suicide 2 months after study entry (and 6 weeks after treatment with sildenafil had been completed). Among the 10 survivors, at 90 days, median NIHSS score was 2 (range 0-12), median Barthel index was 95 (range 15-100), and median modified Rankin score was 1.5 (range 0-5). CONCLUSIONS Sildenafil (25 mg daily for 2 weeks) appeared to be safe in this group of patients with mild to moderately severe stroke. Further studies of higher doses will be tested.


Academic Emergency Medicine | 2003

Treatment of Acute Stroke with Recombinant Tissue Plasminogen Activator and Abciximab

Daniel C. Morris; Brian Silver; Panos Mitsias; Christopher Lewandowski; Suresh C. Patel; Sheila Daley; Zheng G. Zhang; Mei Lu

OBJECTIVES Preclinical data suggest that treatment of acute ischemic stroke (AIS) with the combination of recombinant tissue plasminogen activator (rt-PA) and abciximab may increase efficacy and decrease the rate of symptomatic intracranial hemorrhage (sICH). The authors report pilot data of five AIS patients with half-dose rt-PA and abciximab as part of an ongoing phase I safety trial with sICH as the primary outcome. METHODS Five patients with AIS were treated with the combination of half-dose rt-PA (0.45 mg/kg) and abciximab (0.25 mg/kg bolus followed by a 0.125 microg/kg/min infusion over 12 hours). Head computed tomographic scan was obtained after 24 hours of treatment onset. RESULTS Four patients received the combination of half-dose abciximab and rt-PA without major complications. One patient experienced a parenchymal hematoma type-1 ICH without significant decline of his neurological status. The average National Institutes of Health Stroke Scale change at discharge in comparison with pretreatment was -5.4 +/- 7.0, and the median change was 6 points with a range of 4 points (worsening) to -13 points (improvement) (p=0.07) based on a one-sided t-test. CONCLUSIONS Administration of rt-PA and abciximab to AIS patients was completed without difficulty. No sICH were observed; however, 20% (1 out of 5) experienced an asymptomatic ICH. Based on our observation of five patients, there was a trend of treatment efficacy; however, these results need to be confirmed in a larger-scale placebo-controlled clinical trial.


Critical Care Medicine | 1993

Simultaneous radial, femoral, and aortic arterial pressures during human cardiopulmonary resuscitation.

Emanuel P. Rivers; Joseph Lozon; Enrique Enriquez; Suzanne V. Havstad; Gerard B. Martin; Christopher Lewandowski; Mark G. Goetting; Jack A. Rosenberg; Norman A. Paradis; Richard M. Nowak

Objective.To examine the validity of interchanging arterial sites and their responses to graded doses of epinephrine during human cardiopulmonary resuscitation (CPR). Design.Consecutive case series. Setting.Large, urban Emergency Department. Patients.Adult, normothermic, nonhemor-rhagic cardiac arrest patients. Interventions.While receiving advanced cardiac life support, patients received right atrial (n = 40), aortic (n = 40), radial (n = 40), and femoral (n = 17) artery catheters. Pressures were measured simultaneously at baseline, after 0.01 mg/ kg and 0.2 mg/kg of epinephrine. Measurements and Main Results.The mean aortic compression-phase pressure was 9.3 ± 10 (SD), 8.1 ± 11, and 4.4 ± 9.5 mm Hg higher than radial artery pressure at baseline, after 0.01 mg/ kg, and 0.2 mg/kg of epinephrine, respectively (all statistically significant). When compared with the femoral artery at the same time points, the mean aortic compression-phase pressure was also 3.0 ± 6.8,1.9 ± 8, and 0.6 ± 7.7 mm Hg higher, respectively (none statistically significant). The aortic relaxation-phase pressure was 1.3 ± 3.6, 1.1 ± 3.8, and 1.6 ± 2.5 mm Hg lower than the radial artery at baseline, after 0.01 mg/kg and 0.2 mg/kg of epinephrine, respectively (all statistically significant). When compared with the femoral artery at the same time points, the aortic relaxation-phase pressure was 0.6 ± 2.0,0.3 ± 3.3, and 0.3 ± 2A mm Hg lower, respectively (none statistically significant). Conclusions.Radial artery relaxation-phase pressure, although statistically higher, correlated with aortic relaxation-phase pressure. Femoral artery relaxation-phase pressure was not statistically different from aortic relaxation-phase pressure. Aortic pressure was statistically higher and had a lower correlation with radial artery pressures during compression phase. The aortic to radial artery and aortic to femoral artery compression-phase gradients abated with increasing doses of epinephrine therapy. Caution must be used when substituting compression-phase pressure obtained at radial or femoral artery sites for aortic pressure during human CPR. Coronary artery perfusion pressures obtained with radial and femoral arteries correlate with aortic pressure when measuring the response to vasopressor therapy during CPU when an interpretable waveform exists. (Crit Care Med 1993; 21:878–883)

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Dive into the Christopher Lewandowski's collaboration.

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Claire Pearson

Detroit Receiving Hospital

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Samuel A. McLean

University of North Carolina at Chapel Hill

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Mei Lu

Henry Ford Health System

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Michael C. Kurz

University of Alabama at Birmingham

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James C. Grotta

University of Texas Health Science Center at Houston

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Sarah D. Linnstaedt

University of North Carolina at Chapel Hill

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