Lauralyn McIntyre

Ottawa Hospital Research Institute, Ottawa, Ontario, Canada

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Publications (85)419.04 Total impact

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    ABSTRACT: Bacteremia is a leading cause of mortality and morbidity in critically ill adults. No previous randomized controlled trials have directly compared shorter versus longer durations of antimicrobial treatment in these patients. This is a multicenter pilot randomized controlled trial in critically ill patients with bacteremia. Eligible patients will be adults with a positive blood culture with pathogenic bacteria identified while in the intensive care unit. Eligible, consented patients will be randomized to either 7 days or 14 days of adequate antimicrobial treatment for the causative pathogen(s) detected on blood cultures. The diversity of pathogens and treatment regimens precludes blinding of patient and clinicians, but allocation concealment will be extended to day 7 and outcome adjudicators will be blinded. The primary outcome for the main trial will be 90-day mortality. The primary outcome for the pilot trial is feasibility defined by (i) rate of recruitment exceeding 1 patient per site per month and (ii) adherence to treatment duration protocol ≥ 90%. Secondary outcomes include intensive care unit, hospital and 90-day mortality rates, relapse rates of bacteremia, antibiotic-related side effects and adverse events, rates of Clostridium difficile infection, rates of secondary infection or colonization with antimicrobial resistant organisms, ICU and hospital lengths of stay, mechanical ventilation and vasopressor duration in intensive care unit, and procalcitonin levels on the day of randomization, and day 7, 10 and 14 after the index blood culture. The BALANCE pilot trial will inform the design and execution of the subsequent BALANCE main trial, which will evaluate shorter versus longer duration treatment for bacteremia in critically ill patients, and thereby provide an evidence basis for treatment duration decisions for these infections. The Pilot Trial was registered on 26 September 2014. NCT02261506 .
    Trials 04/2015; 16(1):173. DOI:10.1186/s13063-015-0688-z · 2.12 Impact Factor
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    ABSTRACT: Background Aneurysmal subarachnoid hemorrhage (aSAH) is a devastating disease that leads to important morbidity and mortality in a young patient population. Anemia following aSAH is common and may be exacerbated by the treatments instituted by clinicians as part of standard care. The role and optimal thresholds for red blood cell (RBC) transfusion in this patient population remains unknown. Methods/design We will conduct a systematic review of the literature using MEDLINE, EMBASE, and EBM Reviews (including Cochrane Central databases) using a comprehensive search strategy for observational and interventional studies of RBC transfusion in aSAH. Our primary objective is to evaluate the association of RBC transfusion with mortality in aSAH patients. Secondary objectives include a) determining associations between RBC transfusion and poor neurologic outcome, b) defining an optimal RBC transfusion threshold in aSAH patients, and c) describing complications associated with RBC transfusion in aSAH patients. We plan a descriptive reporting of all included citations including study characteristics, methodological quality, and reported outcomes. Clinical and statistical heterogeneity observed between studies will be described. If appropriate, meta-analyses of suitable studies and interpretation of their results will be performed. Effect measures will be converted to obtain relative risks and odds ratios (RR and ORs) with 95% confidence intervals and pooled according to study design (randomized trials and observational studies respectively) using a random effects model. Discussion This review will summarize the existing observational and trial evidence regarding RBC transfusion in aSAH patients. The analytical plan has made considerations for different study designs, both observational and interventional in nature, and will summarize the best available evidence to inform the end user and policy and guideline producers and to highlight areas in need of further study. Systematic review registration PROSPERO CRD42014014806
    04/2015; 4. DOI:10.1186/s13643-015-0035-1
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    ABSTRACT: Fresh red cells may improve outcomes in critically ill patients by enhancing oxygen delivery while minimizing the risks of toxic effects from cellular changes and the accumulation of bioactive materials in blood components during prolonged storage. In this multicenter, randomized, blinded trial, we assigned critically ill adults to receive either red cells that had been stored for less than 8 days or standard-issue red cells (the oldest compatible units available in the blood bank). The primary outcome measure was 90-day mortality. Between March 2009 and May 2014, at 64 centers in Canada and Europe, 1211 patients were assigned to receive fresh red cells (fresh-blood group) and 1219 patients were assigned to receive standard-issue red cells (standard-blood group). Red cells were stored a mean (±SD) of 6.1±4.9 days in the fresh-blood group as compared with 22.0±8.4 days in the standard-blood group (P<0.001). At 90 days, 448 patients (37.0%) in the fresh-blood group and 430 patients (35.3%) in the standard-blood group had died (absolute risk difference, 1.7 percentage points; 95% confidence interval [CI], -2.1 to 5.5). In the survival analysis, the hazard ratio for death in the fresh-blood group, as compared with the standard-blood group, was 1.1 (95% CI, 0.9 to 1.2; P=0.38). There were no significant between-group differences in any of the secondary outcomes (major illnesses; duration of respiratory, hemodynamic, or renal support; length of stay in the hospital; and transfusion reactions) or in the subgroup analyses. Transfusion of fresh red cells, as compared with standard-issue red cells, did not decrease the 90-day mortality among critically ill adults. (Funded by the Canadian Institutes of Health Research and others; Current Controlled Trials number, ISRCTN44878718.).
    New England Journal of Medicine 03/2015; 372(15). DOI:10.1056/NEJMoa1500704 · 54.42 Impact Factor
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    ABSTRACT: When used appropriately, transfusion of red blood cells (RBCs) is a necessary life-saving therapy. However, RBC transfusions have been associated with negative outcomes such as infection and organ damage. Seeking explanations for the beneficial and deleterious effects of RBC transfusions is necessary to ensure the safe and optimal use of this precious resource. This study will create a framework to analyse the influence of blood donor characteristics on recipient outcomes. We will conduct a multisite, longitudinal cohort study using blood donor data routinely collected by Canadian Blood Services, and recipient data from health administrative databases. Our project will include a thorough validation of primary data, the linkage of various databases into one large longitudinal database, an in-depth epidemiological analysis and a careful interpretation and dissemination of the results to assist the decision-making process of clinicians, researchers and policymakers in transfusion medicine. Our primary donor characteristic will be age of blood donors and our secondary donor characteristics will be donor-recipient blood group compatibility and blood donor sex. Our primary recipient outcome will be a statistically appropriate survival analysis post-RBC transfusion up to a maximum of 8 years. Our secondary recipient outcomes will include 1-year, 2-year and 5-year mortality; hospital and intensive care unit length of stay; rehospitalisation; new cancer and cancer recurrence rate; infection rate; new occurrence of myocardial infarctions and need for haemodialysis. Our results will help determine whether we need to tailor transfusion based on donor characteristics, and perhaps this will improve patient outcome. Our results will be customised to target the different stakeholders involved with blood transfusions and will include presentations, peer-reviewed publications and the use of the dissemination network of blood supply organisations. We obtained approval from the Research Ethics boards and privacy offices of all involved institutions. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
    BMJ Open 01/2015; 5(1):e007412. DOI:10.1136/bmjopen-2014-007412 · 2.06 Impact Factor
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    ABSTRACT: Venous thromboembolism (VTE) is a common complication of critical illness with important clinical consequences. The Prophylaxis for ThromboEmbolism in Critical Care Trial (PROTECT) is a multicenter, blinded, randomized controlled trial comparing the effectiveness of the two most common pharmocoprevention strategies, unfractionated heparin (UFH) and low molecular weight heparin (LMWH) dalteparin, in medical-surgical patients in the intensive care unit (ICU). E-PROTECT is a prospective and concurrent economic evaluation of the PROTECT trial. The primary objective of E-PROTECT is to identify and quantify the total (direct and indirect, variable and fixed) costs associated with the management of critically ill patients participating in the PROTECT trial, and, to combine costs and outcome results to determine the incremental cost-effectiveness of LMWH versus UFH, from the acute healthcare system perspective, over a data-rich time horizon of ICU admission and hospital admission. We derive baseline characteristics and probabilities of in-ICU and in-hospital events from all enrolled patients. Total costs are derived from centers, proportional to the numbers of patients enrolled in each country. Direct costs include medication, physician and other personnel costs, diagnostic radiology and laboratory testing, operative and non-operative procedures, costs associated with bleeding, transfusions and treatment-related complications. Indirect costs include ICU and hospital ward overhead costs. Outcomes are the ratio of incremental costs per incremental effects of LMWH versus UFH during hospitalization; incremental cost to prevent a thrombosis at any site (primary outcome); incremental cost to prevent a pulmonary embolism, deep vein thrombosis, major bleeding event or episode of heparin-induced thrombocytopenia (secondary outcomes) and incremental cost per life-year gained (tertiary outcome). Pre-specified subgroups and sensitivity analyses will be performed and confidence intervals for the estimates of incremental cost-effectiveness will be obtained using bootstrapping. This economic evaluation employs a prospective costing methodology concurrent with a randomized controlled blinded clinical trial, with a pre-specified analytic plan, outcome measures, subgroup and sensitivity analyses. This economic evaluation has received only peer-reviewed funding and funders will not play a role in the generation, analysis or decision to submit the manuscripts for publication.Trial registration: Clinicaltrials.gov Identifier: NCT00182143. Date of registration: 10 September 2005.
    Trials 12/2014; 15(1):502. DOI:10.1186/1745-6215-15-502 · 2.12 Impact Factor
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    ABSTRACT: Vitamin D deficiency may represent a modifiable risk factor to improve outcome in severe illness. The efficacy of high-dose regimens in rapid normalization of vitamin D levels is uncertain. We conducted a systematic review of pediatric clinical trials administering high-dose vitamin D to evaluate 25-hydroxyvitamin D (25[OH]D) response and characteristics associated with final 25(OH)D levels by using Medline, Embase, and the Cochrane Central Register of Controlled Trials, including reference lists of systematic reviews and eligible publications. Uncontrolled and controlled trials reporting 25(OH)D levels after high-dose (≥1000 IU) ergocalciferol or cholecalciferol were selected. Two reviewers independently extracted and verified predefined data fields. We identified 88 eligible full-text articles. Two of 6 studies that administered daily doses approximating the Institute of Medicine's Tolerable Upper Intake Level (1000-4000 IU) to vitamin D-deficient populations achieved group 25(OH)D levels >75 nmol/L within 1 month. Nine of 10 studies evaluating loading therapy (>50 000 IU) achieved group 25(OH)D levels >75 nmol/L. In meta-regression, baseline 25(OH)D, regimen type, dose, age, and time factors were associated with final 25(OH)D levels. Adverse event analysis identified increased hypercalcemia risk with doses >400 000 IU, but no increased hypercalcemia or hypercalciuria with loading doses <400 000 IU (or 10 000 IU/kg). Few studies in adolescents evaluated loading dose regimens >300 000 IU. Rapid normalization of vitamin D levels is best achieved by using loading therapy that considers disease status, baseline 25(OH)D, and age (or weight). Loading doses >300 000 IU should be avoided until trials are conducted to better evaluate risk and benefit. Copyright © 2015 by the American Academy of Pediatrics.
    Pediatrics 12/2014; 135(1). DOI:10.1542/peds.2014-1703 · 5.30 Impact Factor
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    ABSTRACT: To evaluate the efficacy and safety of heparin in patients with sepsis, septic shock, or disseminated intravascular coagulation associated with infection. Systematic review and metaanalysis. Randomized controlled trials from MEDLINE, EMBASE, CENTRAL, Global Health, Scopus, Web of Science, the International Clinical Trials Registry Platform (inception to April 2014), conference proceedings, and reference lists of relevant articles. Two reviewers independently identified and extracted trial-level data from randomized trials investigating unfractionated or low molecular heparin administered to patients with sepsis, severe sepsis, septic shock, or disseminated intravascular coagulation associated with infection. Internal validity was assessed in duplicate using the Risk of Bias tool. The strength of evidence was assessed in duplicate using Grading of Recommendations Assessment, Development, and Evaluation methodology. Our primary outcome was mortality. Safety outcomes included hemorrhage, transfusion, and thrombocytopenia. We included nine trials enrolling 2,637 patients. Eight trials were of unclear risk of bias and one was classified as having low risk of bias. In trials comparing heparin to placebo or usual care, the risk ratio for death associated with heparin was 0.88 (95% CI, 0.77-1.00; I = 0%; 2,477 patients; six trials; moderate strength of evidence). In trials comparing heparin to other anticoagulants, the risk ratio for death was 1.30 (95% CI, 0.78-2.18; I = 0%; 160 patients; three trials; low strength of evidence). In trials comparing heparin to placebo or usual care, major hemorrhage was not statistically significantly increased (risk ratio, 0.79; 95% CI, 0.53-1.17; I = 0%; 2,392 patients; three trials). In one small trial of heparin compared with other anticoagulants, the risk of major hemorrhage was significantly increased (2.14; 95% CI, 1.07-4.30; 48 patients). Important secondary and safety outcomes, including minor bleeding, were sparsely reported. Heparin in patients with sepsis, septic shock, and disseminated intravascular coagulation associated with infection may be associated with decreased mortality; however, the overall impact remains uncertain. Safety outcomes have been underreported and require further study. Increased major bleeding with heparin administration cannot be excluded. Large rigorous randomized trials are needed to evaluate more carefully the efficacy and safety of heparin in patients with sepsis, severe sepsis, and septic shock.
    Critical Care Medicine 12/2014; 43(3). DOI:10.1097/CCM.0000000000000763 · 6.15 Impact Factor
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    ABSTRACT: To identify risk factors for failure of anticoagulant thromboprophylaxis in critically ill patients in the ICU. Multivariable regression analysis of thrombosis predictors from a randomized thromboprophylaxis trial. Sixty-seven medical-surgical ICUs in six countries. Three thousand seven hundred forty-six medical-surgical critically ill patients. All patients received anticoagulant thromboprophylaxis with low-molecular-weight heparin or unfractionated heparin at standard doses. Independent predictors for venous thromboembolism, proximal leg deep vein thrombosis, and pulmonary embolism developing during critical illness were assessed. A total of 289 patients (7.7%) developed venous thromboembolism. Predictors of thromboprophylaxis failure as measured by development of venous thromboembolism included a personal or family history of venous thromboembolism (hazard ratio, 1.64; 95% CI, 1.03-2.59; p = 0.04) and body mass index (hazard ratio, 1.18 per 10-point increase; 95% CI, 1.04-1.35; p = 0.01). Increasing body mass index was also a predictor for developing proximal leg deep vein thrombosis (hazard ratio, 1.25; 95% CI, 1.06-1.46; p = 0.007), which occurred in 182 patients (4.9%). Pulmonary embolism occurred in 47 patients (1.3%) and was associated with body mass index (hazard ratio, 1.37; 95% CI, 1.02-1.83; p = 0.035) and vasopressor use (hazard ratio, 1.84; 95% CI, 1.01-3.35; p = 0.046). Low-molecular-weight heparin (in comparison to unfractionated heparin) thromboprophylaxis lowered pulmonary embolism risk (hazard ratio, 0.51; 95% CI, 0.27-0.95; p = 0.034) while statin use in the preceding week lowered the risk of proximal leg deep vein thrombosis (hazard ratio, 0.46; 95% CI, 0.27-0.77; p = 0.004). Failure of standard thromboprophylaxis using low-molecular-weight heparin or unfractionated heparin is more likely in ICU patients with elevated body mass index, those with a personal or family history of venous thromboembolism, and those receiving vasopressors. Alternate management or incremental risk reduction strategies may be needed in such patients.
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    ABSTRACT: Venous thromboembolism (VTE) is a common complication of acute illness, and its prevention is a ubiquitous aspect of inpatient care. A multicenter blinded, randomized trial compared the effectiveness of the most common pharmocoprevention strategies, unfractionated heparin (UFH) and the low-molecular-weight heparin (LMWH) dalteparin, finding no difference in the primary end point of leg deep-vein thrombosis but a reduced rate of pulmonary embolus and heparin-induced thrombocytopenia among critically ill medical-surgical patients who received dalteparin.
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    ABSTRACT: Background Acute respiratory distress syndrome (ARDS) in humans is caused by an unchecked proinflammatory response that results in diffuse and severe lung injury, and it is associated with a mortality rate of 35 to 45%. Mesenchymal stromal cells (MSCs; ‘adult stem cells’) could represent a promising new therapy for this syndrome, since preclinical evidence suggests that MSCs may ameliorate lung injury. Prior to a human clinical trial, our aim is to conduct a systematic review to compare the efficacy and safety of MSC therapy versus controls in preclinical models of acute lung injury that mimic some aspects of the human ARDS. Methods/Design We will include comparative preclinical studies (randomized and non-randomized) of acute lung injury in which MSCs were administered and outcomes compared to animals given a vehicle control. The primary outcome will be death. Secondary outcomes will include the four key features of preclinical acute lung injury as defined by the American Thoracic Society consensus conference (histologic evidence of lung injury, altered alveolar capillary barrier, lung inflammatory response, and physiological dysfunction) and pathogen clearance for acute lung injury models that are caused by infection. Electronic searches of MEDLINE, Embase, BIOSIS Previews, and Web of Science will be constructed and reviewed by the Peer Review of Electronic Search Strategies (PRESS) process. Search results will be screened independently and in duplicate. Data from eligible studies will be extracted, pooled, and analyzed using random effects models. Risk of bias will be assessed using the Cochrane risk of bias tool, and individual study reporting will be assessed according to the Animal Research: Reporting of In Vivo Experiments (ARRIVE) guidelines. Discussion The results of this systematic review will comprehensively summarize the safety and efficacy of MSC therapy in preclinical models of acute lung injury. Our results will help translational scientists and clinical trialists to determine whether sufficient evidence exists to perform a human clinical trial. These results may also guide future acute lung injury preclinical and clinical research.
    05/2014; 3(1):48. DOI:10.1186/2046-4053-3-48
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    ABSTRACT: Controversies regarding the process and timing of the determination of death for controlled organ donation after circulatory death persist. This study assessed the feasibility of conducting a prospective, observational study of continuous monitoring of vital signs for 30 minutes after the clinical determination of death in five Canadian ICUs. Waveform data were analyzed. Prospective observational cohort study. One pediatric and four adult Canadian ICUs. One month of age or older, admitted to the ICU, and for whom a consensual decision to withdraw life-sustaining therapies had been made, with an anticipation of imminent death. None. Invasive arterial blood pressure, electrocardiogram, and oxygen saturation plethysmography activity were recorded and reviewed for 30 minutes after declaration of death. Feasibility was assessed (recruitment, consent rate, protocol compliance, and staff satisfaction). Of 188 subjects screened over 16 months, 41 subjects were enrolled (87% consent rate). Data collection was complete for 30 subjects (73% protocol compliance). In four subjects, arterial blood pressure resumed following cessation of activity. The longest period of cessation of arterial blood pressure before resumption was 89 seconds. The duration of resumed activity ranged from 1 to 172 seconds. No cases of sustained resumption of arterial blood pressure activity were recorded, and no instances of clinical autoresuscitation were reported. In nearly all patients (27 of 30), electrocardiogram activity continued after the disappearance of arterial blood pressure. This is the first observational study to prospectively collect waveform data for 30 minutes after the declaration of death. A future larger study may support initial data suggesting that circulatory function does not resume after more than 89 seconds of absence. Furthermore, persistence of cardiac electrical activity with the documented absence of circulation may not be relevant to declaration of death.
    Critical care medicine 05/2014; 42(11). DOI:10.1097/CCM.0000000000000417 · 6.15 Impact Factor
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    ABSTRACT: Prolonged ventilation and failed extubation are associated with increased harm and cost. The added value of heart and respiratory rate variability (HRV and RRV) during spontaneous breathing trials (SBTs) to predict extubation failure remains unknown. We enrolled 721 patients in a multicenter (12 sites), prospective, observational study, evaluating clinical estimates of risk of extubation failure, physiologic measures recorded during SBTs, HRV and RRV recorded before and during the last SBT prior to extubation, and extubation outcomes. We excluded 287 patients because of protocol or technical violations, or poor data quality. Measures of variability (97 HRV, 82 RRV) were calculated from electrocardiogram and capnography waveforms followed by automated cleaning and variability analysis using Continuous Individualized Multiorgan Variability Analysis (CIMVATM) software. Repeated randomized sub-sampling with training, validation, and testing were used to derive and compare predictive models. Of 434 patients with high quality data, 51 (12%) failed extubation. Two HRV and eight RRV measures showed statistically significant association with extubation failure (P <0.0041, 5% false discovery rate). An ensemble average of five univariate logistic regression models using RRV during SBT, yielding a probability of extubation failure (called WAVE score), demonstrated optimal predictive capacity. With repeated random sub-sampling and testing, the model showed mean receiver operating characteristic area under the curve (ROC AUC) of 0.69, higher than heart rate (0.51), rapid shallow breathing index (RBSI; 0.61) and respiratory rate (0.63). After deriving a WAVE model based on all data, training-set performance demonstrated that the model increased its predictive power when applied to patients conventionally considered high risk: a WAVE Score >0.5 in patients with RSBI >105 and perceived high-risk of failure yielded a fold increase in risk of extubation failure of 3.0 (95% confidence interval (CI) 1.2 to 5.2) and 3.5 (95% CI 1.9 to 5.4), respectively. Altered HRV and RRV (during the SBT prior to extubation) are significantly associated with extubation failure. A predictive model using RRV during the last SBT provided optimal accuracy of prediction in all patients, with improved accuracy when combined with clinical impression or RSBI. This model requires a validation cohort to evaluate accuracy and generalizability.Trial registration: ClinicalTrials.gov NCT01237886.
    Critical care (London, England) 04/2014; 18(2):R65. DOI:10.1186/cc13822
  • Cytotherapy 04/2014; 16(4):S111. DOI:10.1016/j.jcyt.2014.01.409 · 3.10 Impact Factor
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    ABSTRACT: Optimal selection of blood donors is of paramount importance in ensuring the safety of blood products. The current selection process is concerned principally with the safety of the blood donor and the safety of the patient that receives the blood. Recent evidence suggests that the characteristics of the donor may affect transfusion outcomes for the recipient. We will conduct a systematic review of the association between major blood donor characteristics and RBC transfusion outcomes. The primary objective is to assess the association of blood donor characteristics and the risk of adverse short-term and long-term clinical outcomes after red blood cell (RBC) transfusion. We will search MEDLINE, EMBASE, Cochrane Central databases, as well as perform manual searches of top transfusion medical journals for prospective and retrospective studies. Study characteristics will be reported and the methodological quality of studies will be assessed. When appropriate, we will provide pooled odds ratio with 95% confidence intervals of the effect estimates, study clinical heterogeneity using pre-defined sensitivity and subgroup analyses, and study statistical heterogeneity using the I2 test. The results of this systematic review will provide an evidence base regarding the potential clinical effects of donor characteristics on transfusion recipients to better guide policy and clinical practice. The evidence gathered from this review will also identify strengths and weaknesses of published studies regarding donor characteristics and transfusion outcomes and will identify knowledge gaps to inform future research in this field of transfusion medicine.Trial registration: PROSPERO Registration Number: CRD42013006726.
    03/2014; 3(1):28. DOI:10.1186/2046-4053-3-28
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    ABSTRACT: IMPORTANCE Critically ill patients are at risk of venous thrombosis, and therefore guidelines recommend daily thromboprophylaxis. Deep vein thrombosis (DVT) commonly occurs in the lower extremities but can occur in other sites including the head and neck, trunk, and upper extremities. The risk of nonleg deep venous thromboses (NLDVTs), predisposing factors, and the association between NLDVTs and pulmonary embolism (PE) or death are unclear. OBJECTIVE To describe the frequency, anatomical location, risk factors, management, and consequences of NLDVTs in a large cohort of medical-surgical critically ill adults. DESIGN, SETTING, AND PARTICIPANTS A nested prospective cohort study in the setting of secondary and tertiary care intensive care units (ICUs). The study population comprised 3746 patients, who were expected to remain in the ICU for at least 3 days and were enrolled in a randomized clinical trial of dalteparin vs standard heparin for thromboprophylaxis. MAIN OUTCOMES AND MEASURES The proportion of patients who had NLDVTs, the mean number per patient, and the anatomical location. We characterized NLDVTs as prevalent or incident (identified within 72 hours of ICU admission or thereafter) and whether they were catheter related or not. We used multivariable regression models to evaluate risk factors for NLDVT and to examine subsequent anticoagulant therapy, associated PE, and death. RESULTS Of 3746 trial patients, 84 (2.2%) developed 1 or more non-leg vein thromboses (superficial or deep, proximal or distal). Thromboses were more commonly incident (n = 75 [2.0%]) than prevalent (n = 9 [0.2%]) (P < .001) and more often deep (n = 67 [1.8%]) than superficial (n = 31 [0.8%]) (P < .001). Cancer was the only independent predictor of incident NLDVT (hazard ratio [HR], 2.22; 95% CI, 1.06-4.65). After adjusting for Acute Physiology and Chronic Health Evaluation (APACHE) II scores, personal or family history of venous thromboembolism, body mass index, vasopressor use, type of thromboprophylaxis, and presence of leg DVT, NLDVTs were associated with an increased risk of PE (HR, 11.83; 95% CI, 4.80-29.18). Nonleg DVTs were not associated with ICU mortality (HR, 1.09; 95% CI, 0.62-1.92) in a model adjusting for age, APACHE II, vasopressor use, mechanical ventilation, renal replacement therapy, and platelet count below 50 × 109/L. CONCLUSIONS AND RELEVANCE Despite universal heparin thromboprophylaxis, nonleg thromboses are found in 2.2% of medical-surgical critically ill patients, primarily in deep veins and proximal veins. Patients who have a malignant condition may have a significantly higher risk of developing NLDVT, and patients with NLDVT, compared with those without, appeared to be at higher risk of PE but not higher risk of death. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00182143.
    JAMA Internal Medicine 03/2014; 174(5). DOI:10.1001/jamainternmed.2014.169 · 13.25 Impact Factor
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    ABSTRACT: Thrombocytopenia occurs in 20% to 45% of critically ill medical-surgical patients. The 4Ts heparin-induced thrombocytopenia (HIT) score (with 4 domains: Thrombocytopenia, Timing of thrombocytopenia, Thrombosis and oTher reason[s] for thrombocytopenia) might reliably identify patients at low risk for HIT. Interobserver agreement on 4Ts scoring is uncertain in this setting. To evaluate whether a published clinical prediction rule (the "4Ts score") reliably rules out HIT in "low-risk" intensive care unit (ICU) patients as assessed by research coordinators (who prospectively scored) and 2 adjudicators (who scored retrospectively) during an international heparin thromboprophylaxis trial (PROTECT, NCT00182143). Of 3746 medical-surgical ICU patients in PROTECT, 794 met the enrollment criteria for this HIT substudy. Enrollment was predicated on one of the following occurring in ICU: platelets less than 50 × 10(9)/L, platelets decreased to 50% of ICU admission value (if admission value <100 × 10(9)/L), any venous thrombosis, or if HIT was otherwise clinically suspected. Independently, 4Ts scores were completed in real time by research coordinators blinded to study drug and laboratory HIT results, and retrospectively by 2 adjudicators blinded to study drug, laboratory HIT results, and research coordinators' scores; the adjudicators arrived at consensus in all cases. Of the 763 patients, 474 had a central or local laboratory HIT test performed and had 4Ts scoring by adjudicators; 432 were scored by trained research coordinators. Heparin-induced thrombocytopenia was defined by a centrally performed positive serotonin release assay (SRA). Of the 474 patients with central adjudication, 407 (85.9%) had a 4Ts score of 3 or lower, conferring a low pretest probability (PTP) of HIT; of these, 6 (1.5% [95% confidence interval, 0.7%-3.2%) had a positive SRA. Fifty-nine (12.4%) had a moderate PTP (4Ts score of 4-5); of these, 4 (6.8%) had a positive SRA. Eight patients had a high PTP (4Ts score of ≥6); of these, 1 (12.5%) had a positive SRA. Raw agreement between research coordinators and central adjudication on each domain of the 4Ts score and low, intermediate, and high PTP was good. However, chance-corrected agreement was variable between adjudicators (weighted κ values of 0.31-0.93) and between the adjudicator consensus and research coordinators (weighted κ values of 0.13 and 0.78). Post hoc review of the 6 SRA-positive cases with an adjudicated low PTP demonstrated that their scores would have been increased if the adjudicators had had additional information on heparin exposure prior to ICU admission. In general, the fourth domain of 4Ts (oTher causes of thrombocytopenia) generated the most disagreement. Real-time 4Ts scoring by research coordinators at the time of testing for HIT was not consistent with 4Ts scores obtained by central adjudicators. The results of this comprehensive HIT testing highlight the need for further research to improve the assessment of PTP scoring of HIT for critically ill patients.
    Journal of critical care 02/2014; DOI:10.1016/j.jcrc.2014.02.004 · 2.19 Impact Factor
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    ABSTRACT: Objective:Hemodynamic instability following emergent endotracheal intubation (EETI) is a potentially life-threatening adverse event. The objectives of this systematic literature review were to document the incidence of postintubation hemodynamic instability (PIHI), to determine the definitions for PIHI used in the available literature, and to examine factors associated with PIHI in adult patients who require EETI.Data Source:Articles published in Medline (1966-August 2012).Study Selection:This systematic review included adult, in-hospital studies of EETIs. Studies with nonemergent or pediatric patient populations were excluded.Data Extraction:Two authors independently performed data abstraction. Disagreements were resolved by a third party. The methodological quality of included studies was assessed with the Newcastle-Ottawa Quality Assessment Scale for Cohort Studies.Data Synthesis:We estimated the pooled prevalence of PIHI across studies using a random effects meta-analysis. Subgroups analyzed included study design, intubation setting, geographic location of the study, physician experience, medications used for sedation, neuromuscular blockade, and definition of PIHI. Eighteen studies were analyzed, with sample sizes from 84 to 2,833 patients. The incidence of PIHI ranged from 5 to 440 cases per 1,000 intubations, with a pooled estimate of 110 cases per 1,000 intubations (95% CI 65-167).Conclusions:PIHI was found to occur in 110 cases per 1,000 in-hospital, emergent intubations. However, heterogeneity among the included studies limits the reliability of this summary estimate. Further investigation is warranted.
    Canadian Journal of Emergency Medicine 01/2014; 16(1):69-79. · 0.66 Impact Factor
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    ABSTRACT: The essential clinical diagnostic components of brain death must include evidence for an established etiology capable of causing brain death, two independent clinical confirmations of the absence of all brainstem reflexes and an apnea test, and exclude confounders that can mimic brain death. Numerous confounders can render the clinical neurological determination of death (NDD) virtually impossible. As such, clinicians must rely on additional ancillary testing.Methods/design: We will conduct a systematic review and a meta-analysis of ancillary testing for the neurological determination of death. The primary objective of this systematic review is to evaluate the accuracy of these ancillary tests compared to the three accepted reference standards: (1) clinical diagnosis, (2) four-vessel angiography and (3) radionuclide imaging. This objective will be investigated using two different populations with different baseline risks of brain death: comatose patients and patients with a neurological determination of death. We will search MEDLINE, EMBASE and the Cochrane Central databases for retrospective and prospective diagnostic test studies and interventional studies. We will report study characteristics and assess methodological quality using QUADAS-2, which is used to assess the quality of diagnostic tests. If pooling is appropriate, we will compute parameter estimates using a bivariate model to produce summary receiver operating curves, summary operating points (pooled sensitivity and specificity), and 95% confidence regions around the summary operating point. Clinical and methodological subgroup and sensitivity analyses will be performed to explore heterogeneity. The results of this project will provide a critical evidence base for the neurological determination of death. The results will help clinicians to select ancillary tests based on the best available evidence. Our systematic review will also identify the strengths and weaknesses in the current evidence for the use of ancillary tests in diagnosing brain death. It will serve as a foundation for further research and the development of prospective studies on currently used or novel techniques for NDD.Protocol registration: PROSPERO Registration Number: CRD42013005907.
    11/2013; 2(1):100. DOI:10.1186/2046-4053-2-100
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    ABSTRACT: Early goal-directed therapy (EGDT) is recommended for sepsis management in current guidelines, but the underpinning evidence is controversial. Clinician beliefs and the capacity to implement all recommended elements of EGDT in emergency departments (EDs) are uncertain. Our study aimed to explore self-reported management of early sepsis by Scottish emergency medicine (EM) and intensive care medicine (ICM) consultants, delineate important differences and determine the guideline recommendations rated most important and deliverable within the ED. A postal survey using a hypothetical patient with septic shock was sent to all EM and ICM consultants practising in Scotland. 67% (76/114) EM and 61% (96/157) ICM consultants responded. Normal saline was preferred by EM respondents ('always/often used': EM 86%, ICM 23%, p<0.0001), whereas ICM respondents preferred Hartmann's solution (EM 42%, ICM 72%, p=0.0164), gelofusin (EM 10%, ICM 63%, p<0.0001) and starch (EM 0%, ICM 24%, p<0.0001). More ICM respondents indicated they used central venous pressure and invasive arterial pressure monitoring in the ED, and initiated vasopressors (EM 57%, ICM 90%, p<0.0001). More ICM consultants used specific haemoglobin transfusion triggers (48% EM, 77% ICM, p=0.0002), but marked variation in haemoglobin triggers and targets was reported. Lactate was rated the most important single resuscitation parameter by both specialties; no ED and only two ICM consultants rated ScVO2 most important. Differences in early fluid and vasopressor management of sepsis exist between Scottish ICM and EM consultants. Transfusion practice is highly variable, suggesting clinical uncertainty. Lactate is considered more important than ScVO2 measurement.
    Emergency Medicine Journal 09/2013; DOI:10.1136/emermed-2013-202883 · 1.78 Impact Factor
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    ABSTRACT: Bleeding frequently complicates critical illness and may have serious consequences. Our objectives are to describe the predictors of major bleeding and the association between bleeding and mortality in medical-surgical critically ill patients receiving heparin thromboprophylaxis. We prospectively studied patients from 67 intensive care units and six countries enrolled in a thromboprophylaxis trial (NCT00182143) comparing dalteparin with unfractionated heparin. Patients with trauma, orthopedic surgery or neurosurgery were excluded. Trained research coordinators used a validated tool to document bleeding, which underwent duplicate independent blinded adjudication. Major bleeding was defined as hypovolemic shock, bleeding into critical sites, requiring an invasive intervention or transfusion of at least two units of red blood cells, or associated with hypotension or tachycardia in the absence of other causes. Adjusted Cox proportional hazard regression analysis was used to identify major bleeding predictors and the association between bleeding and mortality. Among 3,746 patients, bleeding occurred in 208 [5.6 %, 95 % confidence interval (CI) 4.9-6.3 %]. Time-dependent predictors were prolonged activated partial thromboplastin time [hazard ratio (HR) 1.10, 1.05-1.14 per 10 s increase], lower platelet count (HR 1.16, 1.09-1.24 per 50 × 10(9)/L decrease), therapeutic heparin (HR 3.26, 1.72-6.17), antiplatelet agents (HR 1.38, 1.02-1.88), renal replacement therapy (HR 1.75, 1.20-2.56), and recent surgery (HR 1.64, 1.01-2.65). Type of pharmacologic thromboprophylaxis was not associated with bleeding. Patients with bleeding had a higher risk of in-hospital death (HR 2.09, 1.69-2.57). As major bleeding has modifiable risk factors and is associated with in-hospital mortality, strategies to mitigate these factors should be evaluated in critically ill patients.
    European Journal of Intensive Care Medicine 08/2013; 39(12). DOI:10.1007/s00134-013-3044-3 · 5.54 Impact Factor

Publication Stats

2k Citations
419.04 Total Impact Points

Institutions

  • 2005–2015
    • Ottawa Hospital Research Institute
      • Clinical Epidemiology Program
      Ottawa, Ontario, Canada
  • 2004–2014
    • The Ottawa Hospital
      • • Department of Medicine
      • • Department of Pharmacy
      Ottawa, Ontario, Canada
  • 2003–2014
    • University of Ottawa
      • • Department of Medicine
      • • Department of Surgery
      • • Department of Epidemiology and Community Medicine
      Ottawa, Ontario, Canada
  • 2012
    • University of Alberta
      • Department of Emergency Medicine
      Edmonton, Alberta, Canada
  • 2010
    • Dalhousie University
      • Department of Emergency Medicine
      Halifax, Nova Scotia, Canada