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.</p

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.</p

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.</p

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 = 20 466) occurred during weekends in 18%, nights in 41%, and nights and/or weekends in 49%. Among the 17 864 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.</p

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.</p

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 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.</p

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 ≥38.3°C and high fever by ≥39.5°C. SETTING: Calgary Health Region during 2000-2006. PATIENTS: All adults (≥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 ≥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.</p

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 (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.</p

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.</p