Showing papers by "Ryan Zarychanski published in 2009"

Critically ill patients with 2009 influenza A(H1N1) infection in Canada.

Abstract: Context Between March and July 2009, the largest number of confirmed cases of 2009 influenza A(H1N1) infection occurred in North America. Objective To describe characteristics, treatment, and outcomes of critically ill patients in Canada with 2009 influenza A(H1N1) infection. Design, Setting, and Patients A prospective observational study of 168 critically ill patients with 2009 influenza A(H1N1) infection in 38 adult and pediatric intensive care units (ICUs) in Canada between April 16 and August 12, 2009. Main Outcome Measures The primary outcome measures were 28-day and 90-day mortality. Secondary outcomes included frequency and duration of mechanical ventilation and duration of ICU stay. Results Critical illness occurred in 215 patients with confirmed (n = 162), probable (n = 6), or suspected (n = 47) community-acquired 2009 influenza A(H1N1) infection. Among the 168 patients with confirmed or probable 2009 influenza A(H1N1), the mean (SD) age was 32.3 (21.4) years; 113 were female (67.3%) and 50 were children (29.8%). Overall mortality among critically ill patients at 28 days was 14.3% (95% confidence interval, 9.5%-20.7%). There were 43 patients who were aboriginal Canadians (25.6%). The median time from symptom onset to hospital admission was 4 days (interquartile range [IQR], 2-7 days) and from hospitalization to ICU admission was 1 day (IQR, 0-2 days). Shock and nonpulmonary acute organ dysfunction was common (Sequential Organ Failure Assessment mean [SD] score of 6.8 [3.6] on day 1). Neuraminidase inhibitors were administered to 152 patients (90.5%). All patients were severely hypoxemic (mean [SD] ratio of PaO 2 to fraction of inspired oxygen [FIO 2 ] of 147 [128] mm Hg) at ICU admission. Mechanical ventilation was received by 136 patients (81.0%). The median duration of ventilation was 12 days (IQR, 6-20 days) and ICU stay was 12 days (IQR, 5-20 days). Lung rescue therapies included neuromuscular blockade (28% of patients), inhaled nitric oxide (13.7%), high-frequency oscillatory ventilation (11.9%), extracorporeal membrane oxygenation (4.2%), and prone positioning ventilation (3.0%). Overall mortality among critically ill patients at 90 days was 17.3% (95% confidence interval, 12.0%-24.0%; n = 29). Conclusion Critical illness due to 2009 influenza A(H1N1) in Canada occurred rapidly after hospital admission, often in young adults, and was associated with severe hypoxemia, multisystem organ failure, a requirement for prolonged mechanical ventilation, and the frequent use of rescue therapies.Published online October 12, 2009 (doi:10.1001/jama.2009.1496).

Clinical review: a review and analysis of heart rate variability and the diagnosis and prognosis of infection.

Abstract: Bacterial infection leading to organ failure is the most common cause of death in critically ill patients. Early diagnosis and expeditious treatment is a cornerstone of therapy. Evaluating the systemic host response to infection as a complex system provides novel insights: however, bedside application with clinical value remains wanting. Providing an integrative measure of an altered host response, the patterns and character of heart rate fluctuations measured over intervals-in-time may be analysed with a panel of mathematical techniques that quantify overall fluctuation, spectral composition, scale-free variation, and degree of irregularity or complexity. Using these techniques, heart rate variability (HRV) has been documented to be both altered in the presence of systemic infection, and correlated with its severity. In this review and analysis, we evaluate the use of HRV monitoring to provide early diagnosis of infection, document the prognostic implications of altered HRV in infection, identify current limitations, highlight future research challenges, and propose improvement strategies. Given existing evidence and potential for further technological advances, we believe that longitudinal, individualized, and comprehensive HRV monitoring in critically ill patients at risk for or with existing infection offers a means to harness the clinical potential of this bedside application of complex systems science.

Renal outcomes and mortality following hydroxyethyl starch resuscitation of critically ill patients: systematic review and meta-analysis of randomized trials

Abstract: Background: Hydroxyethyl starch (HES) is a type of colloid fluid that is commonly used for volume resuscitation of patients admitted to the intensive care unit. Data regarding the renal consequences of HES are conflicting. Purpose: To evaluate the effect of HES solutions on renal outcomes and mortality among critically ill patients requiring acute volume resuscitation. Data sources: We searched electronic databases (MEDLINE, EMBASE, the Cochrane Central Registry of Controlled Trials and the SCOPUS database) from 1950 to 2008. Conference proceedings and grey literature sources were searched from 2002 to 2007. Study selection: We included only randomized controlled trials of acute volume resuscitation of critically ill patients comparing HES fluid with an alternative resuscitation fluid. Data synthesis: Two reviewers independently assessed trial eligibility, extracted data and evaluated trial quality. Random-effects models were used for all summary measures of effect. Results: Twenty-two trials (n = 1865 patients) were included. Patients who received HES were more likely to have received renal replacement therapy (odds ratio [OR] 1.90, 95% confidence interval [CI] 1.22–2.96, I 2 9.5%, n = 749). There was no difference in overall mortality (OR 1.07, 95% CI 0.85–1.34, n = 1657). However, in trials that included patients with severe sepsis and septic shock, in high-quality and multicentre trials, and in trials with adequate allocation concealment, there was a trend toward increased risk of death in association with HES. Limitations: Data regarding adverse events, including renal outcomes, were not reported in the majority of published randomized trials. Considerable clinical and methodologic heterogeneity existed among trials. Conclusions: The use of HES for acute volume resuscitation of critically ill patients, and in particular those with severe sepsis and septic shock, appeared to be associated with increased use of renal replacement therapy. Further randomized controlled trials evaluating clinically important end points are required to examine the efficacy and safety of HES fluids for critically ill patients.

Potential Intensive Care unit Ventilator Demand/Capacity Mismatch due to Novel Swine-Origin H1N1 in Canada

Abstract: PURPOSE: To investigate the ability of Canadian intensive care units (ICUs) and ventilators to handle widespread re-emergence of the swine-origin H1N1 virus in the context of an aggressive strategy of vaccination.

Review Clinical review: A review and analysis of heart rate variability and the diagnosis and prognosis of infection

Abstract: Bacterial infection leading to organ failure is the most common cause of death in critically ill patients. Early diagnosis and expeditious treatment is a cornerstone of therapy. Evaluating the systemic host response to infection as a complex system provides novel insights: however, bedside application with clinical value remains wanting. Providing an integrative measure of an altered host response, the patterns and character of heart rate fluctuations measured over intervals-in-time may be analysed with a panel of mathematical techniques that quantify overall fluctuation, spectral composition, scale-free variation, and degree of irregularity or complexity. Using these techniques, heart rate variability (HRV) has been documented to be both altered in the presence of systemic infection, and correlated with its severity. In this review and analysis, we evaluate the use of HRV monitoring to provide early diagnosis of infection, document the prognostic implications of altered HRV in infection, identify current limitations, highlight future research challenges, and propose improvement strategies. Given existing evidence and potential for further technological advances, we believe that longitudinal, individualized, and comprehensive HRV monitoring in critically ill patients at risk for or with existing infection offers a means to harness the clinical potential of this bedside application of complex systems science.