Publications (8)28.21 Total impact
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Article: Cost-effectiveness of specialized multidisciplinary heart failure clinics in Ontario, Canada.
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ABSTRACT: Specialized multidisciplinary clinics have been shown to reduce mortality in heart failure (HF). Our objective was to evaluate the cost-effectiveness of this model of care delivery. We performed a cost-effectiveness analysis, with a 12-year time horizon, from the perspective of the Ontario Ministry of Health and Long-term Care, comparing a standard care cohort, consisting of all patients admitted to hospital with HF in 2005, to a hypothetical cohort treated in HF clinics. Survival curves describing the natural history of HF were constructed using mortality estimates from the Enhanced Feedback for Effective Cardiac Treatment (EFFECT) study. Survival benefits and resource uptake associated with HF clinics were estimated from a meta-analysis of published trials. HF clinics costs were obtained by costing a representative clinic in Ontario. Health-related costs were determined through linkage to administrative databases. Outcome measures included life expectancy (years), costs (in 2008 Canadian dollars) and the incremental cost-effectiveness ratio (ICER). HF clinics were associated with a 29% reduction in all-cause mortality (risk ratio [RR] 0.71; 95% confidence interval [CI] 0.56-0.91) but a 12% increase in hospitalizations (RR 1.12; 95% CI 0.92-1.135). The cost of care in HF clinics was $52 per 30 patient-days. Projected life-expectancy of HF clinic patients was 3.91 years, compared to 3.21 years for standard care. The 12-year cumulative cost per patient in the HF clinic group was $66,532 versus $53,638 in the standard care group. The ICER was $18,259/life-year gained. HF clinics appear to be a cost effective way of delivering ambulatory care to HF patients.Value in Health 12/2010; 13(8):915-21. · 2.19 Impact Factor -
Article: Effects of resuscitation fluid on neurologic physiology after cerebral trauma and hemorrhage.
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ABSTRACT: The current standard of care for fluid resuscitation of hemorrhagic hypotensive patients involves the use of crystalloid solutions. Traumatic brain injury (TBI) is often associated with hemorrhage and hypotension, which can contribute significantly to morbidity and mortality. Guidelines for the choice of fluid resuscitation and the use of red blood cell transfusions are not yet clear in the context of brain injury. Various fluid resuscitation strategies were evaluated in Sprague-Dawley rats using fresh blood, normal saline, hypertonic saline, and albumin fluid resuscitation protocols. Mean arterial blood pressure (MAP) and cerebral oximetry were assessed in hemorrhaged groups and the mean population spike amplitudes (PSA) from the hippocampus were examined in fluid percussion injured (FPI) animals subject to hemorrhage and fluid resuscitation. MAP in control animals, hemorrhage and hemorrhage + albumin treated groups was 82.4 +/- 1.5 mm Hg, 55.7 +/- 1.5 mm Hg, and 97.0 +/- 3.4 mm Hg, respectively. Arterial PaO2 was higher in albumin-treated animals relative to other fluid alternatives. Regional tissue oxygen tension (PbrO2) levels in hemorrhaged animals reached significantly higher levels in albumin treated group compared with in normal saline and hypertonic saline (p < 0.001, p = 0.034, respectively). After FPI+hemorrhage, PSA values in albumin- resuscitated animals were significantly higher than in normal saline-resuscitated animals (p = 0.012). The results of normal saline resuscitation, relative to other fluid alternatives, suggest that a re-evaluation of current treatment strategies in hemorrhagic hypotensive TBI patients is warranted. Albumin demonstrated the greatest beneficial effects on neurophysiology endpoints over crystalloid alternatives. These data suggests that albumin resuscitation may play an important role in the treatment of hemorrhagic hypotension and TBI.The Journal of trauma 03/2008; 64(2):348-57. · 2.48 Impact Factor -
Article: Severe hemodilutional anemia increases cerebral tissue injury following acute neurotrauma.
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ABSTRACT: Anemia may worsen neurological outcomes following traumatic brain injury (TBI) by undefined mechanisms. We hypothesized that hemodilutional anemia accentuates hypoxic cerebral injury following TBI. Anesthetized rats underwent unilateral TBI or sham injury (n > or = 7). Target hemoglobin concentrations between 50 and 70 g/l were achieved by exchanging 40-50% of the blood volume (1:1) with pentastarch. The effect of TBI, anemia, and TBI-anemia was assessed by measuring brain tissue oxygen tension (Pbr(O(2))), regional cerebral blood flow (rCBF), jugular venous oxygen saturation (Sjv(O(2))), cerebral contusion area, and nuclear staining for programmed cell death. Baseline postinjury Pbr(O(2)) values in the TBI and TBI-anemia groups (9.3 +/- 1.3 and 11.3 +/- 4.1 Torr, respectively) were lower than the uninjured controls (18.2 +/- 5.2 Torr, P < 0.05 for both). Hemodilution caused a further reduction in Pbr(O(2)) in the TBI-anemia group relative to the TBI group without anemia (7.8 +/- 2.7 vs. 14.8 +/- 3.9 Torr, P < 0.05). The rCBF remained stable after TBI and increased comparably after hemodilution in both anemia and TBI-anemia groups. The Sjv(O(2)) was elevated after TBI (87.4 +/- 8.9%, P < 0.05) and increased further following hemodilution (95.0 +/- 1.6%, P < 0.05). Cerebral contusion area and nuclear counts for programmed cell death were increased following TBI-anemia (4.1 +/- 3.0 mm(2) and 686 +/- 192, respectively) relative to TBI alone (1.3 +/- 0.3 mm(2) and 404 +/- 133, respectively, P < 0.05 for both). Hemodilutional anemia reduced cerebral Pbr(O(2)) and oxygen extraction and increased cell death following TBI. These results support our hypothesis that acute anemia accentuated hypoxic cerebral injury after neurotrauma.Journal of Applied Physiology 09/2007; 103(3):1021-9. · 3.75 Impact Factor -
Article: Establishing a comprehensive continuum from an evidentiary base to policy development for health technologies: the Ontario experience.
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ABSTRACT: The aim of this study was to describe a comprehensive continuum that has developed in Ontario between government and key stakeholder groups, including hospitals, physicians, academic institutions, clinical epidemiologists, health economists, industry, and bioethicists to achieve evidence-based recommendations for policy development. The various components of the comprehensive model that has evolved to develop an evidentiary platform for policy development are summarized, and the flow between these components is described. The development of the Ontario Health Technology Advisory Committee (OHTAC) and associated programs demonstrate the need to go beyond the traditional steps taken within most health technology assessment paradigms. These components include pragmatic postmarketing studies, human factors, and safety analyses, and formalized interactions with a broad spectrum of potential end-users of each technology, experts, and industry. Thesecomponents, taken together with an expanded systematic review to include a range of economic analyses, and societal impacts augment the traditional systematic review processes. This approach has been found to be important in assisting decision making and has resulted in an 81 percent conversion from evidence to policy consideration for eighty-three technologies that had been assessed at the time this article was submitted. The comprehensive model, centered around OHTAC, has added important new dimensions to health policy by improving its relevance to decision makers and providing an accountable and transparent basis for government to invest appropriately in health technologies. This study could also form a basis for further research into appropriate methodologies and outcome measurements as they relate to each component of this approach.International Journal of Technology Assessment in Health Care 02/2007; 23(3):299-309. · 1.37 Impact Factor -
Article: A phase I, two-center study of the pharmacokinetics and pharmacodynamics of dexmedetomidine in children.
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ABSTRACT: To investigate dexmedetomidine in children, the authors performed an open-label study of the pharmacokinetics and pharmacodynamics of dexmedetomidine. Thirty-six children were assigned to three groups; 24 received dexmedetomidine and 12 received no drug. Three doses of dexmedetomidine, 2, 4, and 6 microg x kg x h, were infused for 10 min. Cardiorespiratory responses and sedation were recorded for 24 h. Plasma concentrations of dexmedetomidine were collected for 24 h and analyzed. Pharmacokinetic variables were determined using nonlinear mixed effects modeling (NONMEM program). Cardiorespiratory responses were analyzed. Thirty-six children completed the study. There was an apparent difference in the pharmacokinetics between Canadian and South African children. The derived volumes and clearances in the Canadian children were V1 = 0.81 l/kg, V2 = 1.0 l/kg, Cl1 (systemic clearance) = 0.013 l x kg x min, Cl2 = 0.030 l x kg x min. The intersubject variabilities for V1, V2, and Cl1 were 45%, 38%, and 22%, respectively. Plasma concentrations in South African children were 29% less than in Canadian children. The volumes and clearances in the South African children were 29% larger. The terminal half-life was 110 min (1.8 h). Median absolute prediction error for the two-compartment mammillary model was 18%. Heart rate and systolic blood pressure decreased with time and with increasing doses of dexmedetomidine. Respiratory rate and oxygen saturation (in air) were maintained. Sedation was transient. The pharmacokinetics of dexmedetomidine in children are predictable with a terminal half-life of 1.8 h. Hemodynamic responses decreased with increasing doses of dexmedetomidine. Respiratory responses were maintained, whereas sedation was transient.Anesthesiology 01/2007; 105(6):1098-110. · 5.36 Impact Factor -
Article: A Phase I, Two-center Study of the Pharmacokinetics and Pharmacodynamics of Dexmedetomidine in Children
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ABSTRACT: Background: To investigate dexmedetomidine in children, the authors performed an open-label study of the pharmacokinetics and pharmacodynamics of dexmedetomidine.Anesthesiology 11/2006; 105(6):1098-1110. · 5.36 Impact Factor -
Article: Development and psychometric evaluation of the pediatric anesthesia emergence delirium scale.
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ABSTRACT: Emergence delirium has been investigated in several clinical trials. However, no reliable and valid rating scale exists to measure this phenomenon in children. Therefore, the authors developed and evaluated the Pediatric Anesthesia Emergence Delirium (PAED) scale to measure emergence delirium in children. A list of scale items that were statements describing the emergence behavior of children was compiled, and the items were evaluated for content validity and statistical significance. Items that satisfied these evaluations comprised the PAED scale. Each item was scored from 1 to 4 (with reverse scoring where applicable), and the scores were summed to obtain a total scale score. The degree of emergence delirium varied directly with the total score. Fifty children were enrolled to determine the reliability and validity of the PAED scale. Scale validity was evaluated using five hypotheses: The PAED scale scores correlated negatively with age and time to awakening and positively with clinical judgment scores and Post Hospital Behavior Questionnaire scores, and were greater after sevoflurane than after halothane. The sensitivity of the scale was also determined. Five of 27 items that satisfied the content validity and statistical analysis became the PAED scale: (1) The child makes eye contact with the caregiver, (2) the child's actions are purposeful, (3) the child is aware of his/her surroundings, (4) the child is restless, and (5) the child is inconsolable. The internal consistency of the PAED scale was 0.89, and the reliability was 0.84 (95% confidence interval, 0.76-0.90). Three hypotheses supported the validity of the scale: The scores correlated negatively with age (r = -0.31, P <0.04) and time to awakening (r = -0.5, P <0.001) and were greater after sevoflurane anesthesia than halothane (P <0.008). The sensitivity was 0.64. These results support the reliability and validity of the PAED scale.Anesthesiology 06/2004; 100(5):1138-45. · 5.36 Impact Factor -
Article: Same day consent for anaesthesia research
Canadian Journal of Anaesthesia 11/1994; 41(12):1234-1234. · 2.35 Impact Factor
Top co-authors
Top Journals
Institutions
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2007
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SickKids
Toronto, Ontario, Canada
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2004
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St. Michael's Hospital
Toronto, Ontario, Canada
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1994
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University of Toronto
- Department of Anesthesia
Toronto, Ontario, Canada
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