Fever in adult ICUs: an interrupted time series analysis*.

OBJECTIVES: Fever is common and associated with increased mortality among patients admitted to adult ICUs, yet recent literature suggests that the incidence of fever may be decreasing. The objective of this study was to determine whether the incidence of fever in adult ICUs changed over time and the factors responsible for the observed change. DESIGNS: Interrupted time series analysis. The primary outcome was the cumulative incidence of fever (temperature ≥ 38.3 °C). Secondary outcomes included the cumulative rate of blood cultures ordered, and the cumulative incidence of bloodstream infections and ventilator-associated pneumonia. Data were analyzed with segmented linear regression and adjusted for important confounding variables. SETTING: Calgary zone of Alberta Health Services between January 1, 2004, and June 30, 2009. PATIENTS: Adults (age ≥ 18 yr) admitted to ICUs. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: There were 18,989 ICU admissions among 17,153 patients. The cumulative incidence of fever during ICU admission decreased from 50.1% of all patients to 25.5% over the 5.5-year study period. Implementation of a new noninvasive thermometer was associated with a 5.1% (95% CI, 1.4-8.9%, p = 0.01) absolute decrease in fever incidence; however, the decrease in fever incidence was predominantly a function of a constant baseline decrease of 1.1% per quarter (95% CI, 0.8-1.5%, p < 0.0001). Multivariate logistic time series regression found that time and thermometer change were the only independent predictors of the changing incidence of fever. The ordering of blood cultures, bloodstream infection incidence, and ICU mortality were unchanged throughout the study period. CONCLUSIONS: The incidence of fever in adult ICUs decreased considerably over time. The lack of change in the ordering of blood cultures and the incidence of bloodstream infections calls into question the importance of fever during the diagnostic evaluation of critically ill patients.

A cohort study of nutrition practices in the intensive care unit following abdominal aortic aneurysm repair.

INTRODUCTION: Enteral nutrition within 48 hours of intensive care unit (ICU) admission is recommended for the ICU population. Major vascular surgery patients have a higher incidence of pre- and postoperative malnutrition compared with the general surgical population. Our objectives were to determine if early feeding (within 48 hours of admission) is achievable and well tolerated, identify factors that predict early feeding, and determine if there is an association between early feeding and in-hospital mortality among abdominal aortic aneurysm (AAA) repair patients. METHODS: A retrospective cohort study was conducted among 145 postsurgical AAA repair patients admitted to the ICU within 48 hours of surgery. Kaplan-Meier methods and Cox proportional hazard multiple regression were used to analyze the data. RESULTS: Only 35 (24%) patients received early feeding. Patients were more likely to be fed early if they were male (adjusted hazard ratio [aHR] = 2.3; 95% confidence interval [CI], 0.8-6.7; P = .13), had endovascular AAA repair (aHR = 2.9; 95% CI, 1.4-6.2; P = .006), had less blood loss (<4 L) during surgery (aHR = 2.3; 95% CI, 0.7-7.2; P = .14), and had shorter length of ventilation (<48 hours) (aHR = 2.2; 95% CI, 1.1-4.8; P = .048). Of 44 patients fed via enteral nutrition (EN), 27 (61%) achieved nutrition adequacy (>80% EN goal) during ICU admission. After controlling for other factors, 14-day mortality was not related to feeding time (aHR = 1.1; P = .88). CONCLUSION: Early feeding was achieved in a minority of patients following AAA repair, was related to type of surgery and duration of mechanical ventilation, and was tolerated as well as later introduced feedings. Randomized trials are needed to determine safety and benefits of early feeding in this patient group.

Tele-ICU - a Canadian review.

Based on the learnings and experiences from implementations in the United States, telemedicine may offer certain advantages to help address some of the challenges faced by the Canadian critical care community resulting from staff shortages and increasing demands for quality care. The initial and operating costs of the technology and its impact on direct bedside care are perceived to be significant drivers of resistance to its wide spread implementation. This qualitative review of the available literature summarizes the opportunities and challenges with the potential use of telemedicine to enhance the delivery of critical care services in Canada.

Sequential Organ Failure Assessment in H1N1 pandemic planning.

OBJECTIVE: The H1N1 pandemic has highlighted the importance of reliable and valid triage instruments. A Sequential Organ Failure Assessment score of >11 has been proposed to exclude patients from critical care resources quoting an associated mortality of >90%. We sought to assess the mortality associated with this Sequential Organ Failure Assessment threshold and the resource implications of such a triage protocol. DESIGN: Retrospective cohort. SETTING: Three multisystem intensive care units. PATIENTS: Consecutive patients admitted from January 2003 to December 2008. Subsequently, a comparison H1N1 cohort was assembled consisting of all patients admitted in 2009 with confirmed H1N1. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Sequential Organ Failure Assessment was collected daily by use of an electronic bedside clinical information system (n = 10,204 patients, 69,913 patient days). Mean admission Acute Physiology and Chronic Health Evaluation was 19.1. 13.4% of the cohort (9% of total patient days) had an initial Sequential Organ Failure Assessment of >11. Mortality in patients with an initial Sequential Organ Failure Assessment score of >11 was 59% (95% confidence interval: 56%, 62%). The mortality associated with an initial Sequential Organ Failure Assessment >11 across diagnostic categories varied from 29% for poisoning to 67% for neurologic patients. Hospital mortality exceeded 90% only when initial Sequential Organ Failure Assessment was >20 (0.2% of patients). H1N1 patients were younger, had a longer intensive care unit length of stay, and more commonly had a respiratory admission diagnosis than the nonH1N1 cohort. Hospital mortality in H1N1 patients with an initial Sequential Organ Failure Assessment score of >11 was 31% (95% confidence interval: 5%, 56%). CONCLUSIONS: A Sequential Organ Failure Assessment score of >11 was not associated with a hospital mortality of >90% at any time during intensive care unit stay. Only a small proportion of patients have the extreme initial Sequential Organ Failure Assessment values associated with a hospital mortality of >90% limiting the usefulness of Sequential Organ Failure Assessment as a triage instrument for pandemic planning. Application of a Sequential Organ Failure Assessment threshold of >11 to the recent H1N1 pandemic would have excluded patients with a markedly lower mortality than seen in a large regional cohort of intensive care unit patients.

Telemedicine in the intensive care unit environment--a survey of the attitudes and perspectives of critical care clinicians.

PURPOSE: This study was conducted to assess the preimplementation knowledge and perceptions of intensive care unit (ICU) clinicians regarding the ability of telemedicine in the ICU environment (Tele-ICU) to address challenges resulting from the shortages of experienced critical care human resources and the drive to improve quality of care. METHODS: An online survey was administered to clinicians from a Canadian multisite critical care department. Qualitative and quantitative analyses were undertaken to identify key positive and negative themes. RESULTS: The overall self-rated knowledge about Tele-ICU was low, with significant uncertainty particularly related to the novelty of the technology, lack of widespread existing implementations, and insufficient education. A significant degree of skepticism was expressed regarding the ability of Tele-ICU to address the challenges of staff shortages and quality of care. CONCLUSIONS: Significant uncertainty and skepticism were expressed by critical care clinicians regarding the ability of Tele-ICU to address the challenges of human resource limitation and the delivery of quality care. This suggests the need for further research and education of system impact beyond patient outcomes related to this new technology.

Management of febrile critically ill adults: a retrospective assessment of regional practice.

The aim of this study was to report on fever epidemiology and management strategies within a general population of critically ill patients. This was a retrospective cohort study among febrile patients (temperature ≥38.3°C) without acute brain injury admitted to one of four regional adult intensive care units (ICUs). There were 7535 ICU admissions over the 30-month study period. One hundred patients with fever were randomly selected for detailed analysis and represent the study population. The study population had a median age (interquartile range) of 56 (43-69) years and a mean (±standard deviation) Acute Physiology and Chronic Health Evaluation II score of 22 (±9). Septic shock was the most common admission diagnosis (36%), followed by pneumonia (without a shock syndrome; 18%). Fifty-three percent of patients had fever at ICU admission. To investigate the etiology of fever, most patients (89%) had at least one culture sent to the laboratory for analysis and a blood culture (73%) was the most commonly ordered microbiologic investigation. A chest X-ray was ordered in 95% of patients within 48 hours of fever onset. The majority of patients had an infection as the cause of their fever (73%), with pneumonia as the most common diagnosis (70%, 51/73). Prior to the occurrence of fever, 74% of patients were on antibiotics and this increased to 85% within the first 24 hours after documentation of fever. Seventy-nine percent of patients were managed with antipyretic drugs (77%) and/or external cooling (29%); however, only five patients had an order written that specifically guided the use of these temperature-lowering agents. Fever was most commonly infectious in origin. Treatment of patients with fever was a common and nonstandardized practice in this cohort of critically ill patients. This is likely due to lack of evidence in support of a particular temperature management strategy.

Concomitant ceftriaxone and high-concentration intravenous calcium therapy in adult critical care patients: a matched cohort study.

BACKGROUND: Based on case reports in infants, the safety of concomitant use of ceftriaxone and intravenous calcium in all ages has recently come under challenge. Systematic population-based data to guide clinicians with respect to this risk are, however, lacking. OBJECTIVE: To determine whether concomitant administration of ceftriaxone and intravenous calcium was associated with the occurrence of severe cardiorespiratory events or death in critically ill adults. METHODS: We performed a matched-cohort study from retrospective data of adults admitted to intensive care units (ICUs) in Calgary, Canada, who were provided continuous high-dose intravenous calcium. Those who received ceftriaxone while on continuous renal replacement therapy were considered exposed. Up to 3 unexposed patients were selected by matching on a number of prognostic factors from the remaining subjects not concurrently exposed to ceftriaxone and calcium. Univariate methods and multivariate conditional logistic regression were used for statistical analysis. RESULTS: We identified 142 patients exposed to the implicated combination who could be matched to at least one unexposed patient. Hospital mortality was 66% in the exposed versus 63% in unexposed patients (p = 0.442). ICU length of stay, ICU mortality, hospital length of stay, and the frequency of acute oxygenation events were all similar by univariate analysis. Multivariate conditional logistic regression modeling failed to find a significant association between exposure and hospital mortality (adjusted OR 1.15, 95% CI 0.65 to 2.04) or other relevant outcomes. CONCLUSIONS: In this high-risk group, administration of high concentrations of calcium and concurrent ceftriaxone was not significantly associated with greater mortality or adverse outcomes compared to matched unexposed patients. Although this was an underpowered study and rare adverse effects from the interaction of these 2 compounds cannot be completely excluded, these data provide overall reassurance of the safety of this combination in the majority of critically ill adults.

Systematized Nomenclature of Medicine-Clinical Terms direction and its implications on critical care.

PURPOSE: The aim of this study was to describe the new advancements in Systematized Nomenclature of Medicine-Clinical Terms (SNOMED-CT) terminology and its applicability to critical care documentation. MATERIALS AND METHODS: Narrative review of existing literature published in indexed medical and health informatics journals and of gray literature available on the Internet and personal communication with authors and researchers engaged in SNOMED-CT projects related to critical care are conducted. RESULTS: Systematized Nomenclature of Medicine-Clinical Terms is a system of comprehensive health and clinical terminology that covers most of the needs of health care documentation. It will potentially become the terminology of clinical enterprise and administrative information systems. Despite a ground swell of international support from health information management experts, the terminology remains unknown to most clinicians. We discuss the reasons why clinical familiarity with SNOMED-CT is an important prerequisite to proceeding with local or national electronic health records or clinical information systems. CONCLUSIONS: We propose that SNOMED-CT is suitable for use in critical care; however, work is urgently required to validate the completeness of terminology and to determine clinicians' perceptions on the utility of such a standardized terminology for use in critical care clinical information systems.

Occurrence and adverse effect on outcome of hyperlactatemia in the critically ill.

INTRODUCTION: Hyperlactatemia is frequent in critically ill patients and is often used as a marker of adverse outcome. However, studies to date have focused on selected intensive care unit (ICU) populations. We sought to determine the occurrence and relation of hyperlactatemia with ICU mortality in all patients admitted to four ICUs in a large regional critical care system. METHODS: All adults ([greater than or equal to] 18 years) admitted to ICUs in the Calgary Health Region (population 1.2 million) during 2003 to 2006 were included retrospectively. Lactate determinations were at the discretion of the attending service and hyperlactatemia was defined by a lactate level > 2 mmol/L. RESULTS: A total of 13,932 ICU admissions occurred among 11,581 patients. The median age was 63 years (37% female), the mean APACHE II score was 25 +/- 9 (n = 13,922). At presentation (within first day of admission), 12,246 patients had at least one lactate determination and the median peak lactate was 1.8 (IQR 1.2 to 2.9) mmol/L. The cumulative incidence of at least one documented episode of hyperlactatemia was 5578/13,932 (40%); 5058 (36%) patients had hyperlactatemia at presentation, and a further 520 (4%) developed hyperlactatemia subsequently. The incidence of hyperlactatemia varied significantly by major admitting diagnostic category (P < 0.001) and was highest among neuro/trauma patients 1053/2328 (45%), followed by medical 2047/4935 (41%), other surgical 900/2274 (40%), and cardiac surgical 1578/4395 (36%). Among a cohort of 9107 first admissions with ICU stay of at least one day, both hyperlactatemia at presentation (712/3634 (20%) vs. 289/5473 (5%); P < 0.001) and its later development (101/379 (27%) vs. 188/5094 (4%); P < 0.001) were associated with significantly increased case fatality rates as compared with patients without elevated lactate. After controlling for confounding effects in multivariable logistic regression analysis, hyperlactatemia was an independent risk factor for death. CONCLUSIONS: Hyperlactatemia is common among the critically ill and predicts risk for death.

Information management framework; a model for clinical departments.

The information management system of Department of Critical Care Medicine in Calgary Health Region was modeled using a departmental information management framework. The clinical, administrative, research and educational, decision-making and quality improvement information needs of the department are served by the system.

Time series analysis of use patterns for common invasive technologies in critically ill patients.

PURPOSE: Critically ill patients are frequently managed with invasive technologies as part of their medical care. Little is known about use patterns. We examined use trends for invasive technologies used in critically ill patients. MATERIALS AND METHODS: Using time series analysis and data on 26 989 patients from 3 medical-surgical intensive care units (ICUs) (n = 18 224) and 1 surgical ICU (n = 8765) between January 1, 1999, and January 1, 2007, we measured changes in the proportion of patients receiving the 4 most frequently used invasive technologies used in critically ill patients. RESULTS: The 4 most common invasive technologies used in critically ill patients during the study period were arterial lines (71%), endotracheal intubations (61%), central venous catheters (51%), and pulmonary artery catheters (18%). The proportion of ICU patients who received pulmonary artery catheters decreased from 25% in 1999 to 8% in 2006 (P < .001). Use of central venous catheters increased from 39% to 46% (P < .001). After adjusting for baseline characteristics, patients admitted in 2006 were 4 times less likely to receive a pulmonary artery catheter (odds ratio, 0.28; 95% confidence interval, 0.24-0.33), but 42% (odds ratio, 1.42; 95% confidence interval, 1.27-1.58) more likely to receive a central venous catheter than patients admitted in 1999. No significant changes were observed for intubations and arterial lines. CONCLUSIONS: The use of invasive technologies in critically ill patients is changing and may have important implications for resource use, clinician education, and patient care. Initiatives should be considered for ensuring clinician competency during technology transitions.

The epidemiology of intensive care unit-acquired hyponatraemia and hypernatraemia in medical-surgical intensive care units.

INTRODUCTION: Although sodium disturbances are common in hospitalised patients, few studies have specifically investigated the epidemiology of sodium disturbances in the intensive care unit (ICU). The objectives of this study were to describe the incidence of ICU-acquired hyponatraemia and hypernatraemia and assess their effects on outcome in the ICU. METHODS: We identified 8142 consecutive adults (18 years of age or older) admitted to three medical-surgical ICUs between 1 January 2000 and 31 December 2006 who were documented to have normal serum sodium levels (133 to 145 mmol/L) during the first day of ICU admission. ICU acquired hyponatraemia and hypernatraemia were respectively defined as a change in serum sodium concentration to below 133 mmol/L or above 145 mmol/L following day one in the ICU. RESULTS: A first episode of ICU-acquired hyponatraemia developed in 917 (11%) patients and hypernatraemia in 2157 (26%) patients with an incidence density of 3.1 and 7.4 per 100 days of ICU admission, respectively, during 29,142 ICU admission days. The incidence of both ICU-acquired hyponatraemia (age, admission diagnosis, Acute Physiology and Chronic Health Evaluation (APACHE) II score, length of ICU stay, level of consciousness, serum glucose level, body temperature, serum potassium level) and ICU-acquired hypernatraemia (baseline creatinine, APACHE II score, mechanical ventilation, length of ICU stay, body temperature, serum potassium level, level of care) varied according to patients' characteristics. Compared with patients with normal serum sodium levels, hospital mortality was increased in patients with ICU-acquired hyponatraemia (16% versus 28%, p < 0.001) and ICU-acquired hypernatraemia (16% versus 34%, p < 0.001). CONCLUSIONS: ICU-acquired hyponatraemia and hypernatraemia are common in critically ill patients and are associated with increased risk of hospital mortality.

Hospital mortality among adults admitted to and discharged from intensive care on weekends and evenings.

PURPOSE: Patient care may be inconsistent during off hours. We sought to determine whether adults admitted to or discharged from intensive care units (ICUs) on evenings and weekends have increased mortality rates. MATERIALS AND METHODS: All adults admitted to ICUs in the Calgary Health Region, Alberta, Canada, during 2000 to 2006 were included. The in-hospital mortality risk was assessed with admissions or discharges on weekdays (Monday to Friday) and daytime (8:00 am to 5:59 pm) as compared with weekends (Saturday and Sunday) and nights (6:00 pm to 7:59 am). RESULTS: Intensive care unit admissions (n = 20466) occurred during weekends in 18%, nights in 41%, and nights and/or weekends in 49%. Among the 17864 survivors to ICU discharge, 26% were discharged on weekends, 21% at night, and 41% on nights and/or weekends. Increased crude mortality rates were associated with both admission (24% vs 14%, P < .0001) and discharge (12% vs 5%, P < .0001) during nights as compared with days. Admission to (26% vs 16%, P < .0001) but not discharge from (6% vs 7%, P = .42) ICU during weekends as compared with weekdays was associated with increased mortality. After controlling for confounding variables using logistic regression analyses, neither weekend admission nor discharge was associated with death. However, both night admission and discharge were independently associated with mortality. CONCLUSIONS: Our observations of excess risk associated with admission to or discharge from ICU at night merits further exploration as to whether it may reflect inconsistencies in care after hours.

Occurrence and outcome of fever in critically ill adults.

OBJECTIVE: Although fever is common in the critically ill, only a small number of studies have specifically investigated its epidemiology in the intensive care unit (ICU). The objective of this study was to describe the occurrence of fever in the critically ill and assess its effect on ICU outcome. DESIGN: Retrospective cohort. Fever was defined by temperature > or = 38.3 degrees C and high fever by > or = 39.5 degrees C. SETTING: Calgary Health Region during 2000-2006. PATIENTS: All adults (> or = 18 yrs) admitted to ICUs. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: A total of 24,204 ICU admission episodes occurred among 20,466 patients; 35% were classified as medical, 33% as cardiac surgical, 16% as other surgical, and 15% as trauma/neurologic. The cumulative incidence of fever and high fever was 44% and 8% and the incidence density was 24.3 and 2.7 per 100 days of ICU admission, respectively. The incidence density of fever was higher in trauma/neuro patients, males, younger patients, and was lower in those with admission Acute Physiology and Chronic Health Evaluation II scores > or = 25. Seventeen percent and 31% of patients with fever and high fever had associated positive cultures. Resolution of fever and high fever occurred in 27% and 53% of patients before ICU discharge and prolonged fever and high fever lasting for 5 or more days in the ICU occurred in 18% and 11% of febrile patients, respectively. Although the presence of fever was not associated with increased ICU mortality (13% vs. 12%; p = .08), high fever was associated with significantly increased risk for death (20.3% vs. 12%, p < .0001). After controlling for confounding factors using multivariable logistic regression models, the influence of fever on the ICU mortality varied significantly according to its timing of onset, degree, and main admission category. CONCLUSIONS: Fever is common in patients admitted to the ICU and its occurrence and impact on outcome varies among defined patient populations.

Study of clinical course of organ dysfunction in intensive care.

OBJECTIVE: Multiple organ dysfunction is a common cause of death in intensive care units. We describe the daily course of multiple organ dysfunction measured by the Sequential Organ Failure Assessment score in a population-based cohort of critically ill patients. DESIGN: Prospective cohort study. SETTING: Adult multisystem intensive care units in the Calgary Health Region. PATIENTS: A total of 1,436 patients admitted from May 1, 2000 to April 30, 2001. MEASUREMENTS: Temporal change in Sequential Organ Failure Assessment score. INTERVENTIONS: None; observational study. MAIN RESULTS: The mean age was 58 yrs (range, 14-100). The mean +/- sd intensive care unit admission Acute Physiology and Chronic Health Evaluation II score was 25 +/- 9. The median intensive care unit length of stay was 4 days (interquartile range, 2-8), and the median hospital length of stay was 15 days (interquartile range, 7-32). A total of 20.5% of patients were infected at admission, and 26.0% were immediately postoperative. Intensive care unit mortality was 27.0%, and hospital mortality was 35.1%. The daily Sequential Organ Failure Assessment score was significantly higher in nonsurvivors than survivors. A population-averaged model determined a mean rate of change of Sequential Organ Failure Assessment score to be -0.29 per day (95% confidence interval, -0.32 to -0.25) for survivors and -0.03 per day (95% confidence interval, -0.08 to 0.03) for nonsurvivors (overall regression, p <.0001). Patients with infection had higher admission Sequential Organ Failure Assessment scores compared with patients without infection (difference, 1.8; p <.001), but a similar rate of daily change. CONCLUSIONS: Multiple organ dysfunction, does not follow a course of progressive and sequential failure. Evidence of differential daily change should further inform the use of organ failure scores as surrogate outcomes in clinical trials.