Lesly A. Dossett

Early prediction of massive transfusion in trauma: Simple as ABC (Assessment of Blood Consumption)?

BACKGROUND Massive transfusion (MT) occurs in about 3% of civilian and 8% of military trauma patients. Although many centers have implemented MT protocols, most do not have a standardized initiation policy. The purpose of this study was to validate previously described MT scoring systems and compare these to a simplified nonlaboratory dependent scoring system (Assessment of Blood Consumption [ABC] score). METHODS Retrospective cohort of all level I adult trauma patients transported directly from the scene (July 2005 to June 2006). Trauma-Associated Severe Hemorrhage (TASH) and McLaughlin scores calculated according to published methods. ABC score was assigned based on four nonweighted parameters: penetrating mechanism, positive focused assessment sonography for trauma, arrival systolic blood pressure of 90 mm Hg or less, and arrival heart rate > or = 120 bpm. Area under the receiver operating characteristic curve (AUROC) used to compare scoring systems. RESULTS Five hundred ninety-six patients were available for analysis; and the overall MT rate of 12.4%. Patients receiving MT had higher TASH (median, 6 vs. 13; p < 0.001), McLaughlin (median, 2.4 vs. 3.4; p < 0.001) and ABC (median, 1 vs. 2; p < 0.001) scores. TASH (AUROC = 0.842), McLaughlin (AUROC = 0.846), and ABC (AUROC = 0.842) scores were all good predictors of MT, and the difference between the scores was not statistically significant. ABC score of 2 or greater was 75% sensitive and 86% specific for predicting MT (correctly classified 85%). CONCLUSIONS The ABC score, which uses nonlaboratory, nonweighted parameters, is a simple and accurate in identifying patients who will require MT as compared with those previously published scores.

Acute lung injury in patients with traumatic injuries: utility of a panel of biomarkers for diagnosis and pathogenesis.

BACKGROUND The diagnosis of acute lung injury (ALI) is based on a consensus clinical definition. Despite the simplicity of this definition, ALI remains underdiagnosed and undertreated. Severe trauma is a well-described cause of ALI that represents a relatively homogeneous subset of patients with ALI. The aims of this study were to develop a panel of plasma biomarkers to facilitate diagnosis of trauma-induced ALI and to enhance our understanding of the pathogenesis of human ALI. METHODS A retrospective nested case control of 192 patients admitted to the trauma intensive care unit at a university hospital between 2002 and 2006. We compared 107 patients with ALI to 85 patients without ALI. Plasma was collected within 72 hours of intensive care unit admission. Twenty-one plasma biomarkers were measured in duplicate in each plasma sample. RESULTS Patients with ALI had higher severity of illness scores, more days of mechanical ventilation, longer hospital stays, and higher mortality versus controls. Seven biomarkers (receptor for advanced glycation end products, procollagen peptide III, brain natriuretic peptide, angiopoietin-2, interleukin-10, tumor necrosis factor alpha, and interleukin-8) had a high diagnostic accuracy as reflected by the area under the receiver operating characteristic curve of 0.86 (95% confidence interval, 0.82-0.92) in differentiating ALI from controls. CONCLUSIONS A model using seven plasma biomarkers had a high diagnostic accuracy in differentiating patients with trauma-induced ALI from trauma patients without ALI. In addition, use of a panel of biomarkers provides insight into the likely importance of alveolar epithelial injury in the pathogenesis of early ALI.

Prevalence and Implications of Preinjury Warfarin Use An Analysis of the National Trauma Databank

OBJECTIVES To describe the prevalence of preinjury warfarin use in a large national sample of trauma patients and to define the relationship between preinjury warfarin use and mortality. DESIGN Retrospective cohort study. SETTING The National Trauma Databank (7.1). PATIENTS All patients admitted to eligible trauma centers during the study period; 1,230,422 patients (36,270 warfarin users) from 402 centers were eligible for analysis. MAIN OUTCOME MEASURES Prevalence of warfarin use and all-cause in-hospital mortality. Multivariate logistic regression was used to estimate the odds ratio (OR) for mortality associated with preinjury warfarin use. RESULTS Warfarin use increased among all patients from 2.3% in 2002 to 4.0% in 2006 (P < .001), and in patients older than 65 years, use increased from 7.3% in 2002 to 12.8% in 2006 (P < .001). Among all patients, 9.3% of warfarin users died compared with only 4.8% of nonusers (OR, 2.02; 95% confidence interval [CI], 1.95-2.10; P < .001). After adjusting for important covariates, warfarin use was associated with increased mortality among all patients (OR, 1.72; 95% CI, 1.63-1.81; P < .001) and patients 65 years and older (OR, 1.38; 95% CI, 1.30-1.47; P < .001). CONCLUSIONS Warfarin use is common among injured patients and its prevalence has increased each year since 2002. Its use is a powerful marker of mortality risk, and even after adjusting for confounding comorbidities, it is associated with a significant increase in death.

Glucose Control and the Inflammatory Response

Though first introduced more than 130 years ago, the concept of stress diabetes or stress hyperglycemia has gained tremendous attention in recent years in view of the landmark article by van den Berghe and colleagues in 2001. As opposed to earlier work that suggested that hyperglycemia in the acute clinical setting may be beneficial, it now appears that lower glucose levels are associated with improved outcomes. The mechanisms behind the improved outcomes are numerous and seem to be tied to the inflammatory process. Both lower glucose values and insulin therapy seem to be anti-inflammatory, whereas hyperglycemia increases the proinflammatory process and negatively affects the innate immune system. Despite the numerous approaches to achieve normoglycemia described in the literature, only modest success has been achieved. Understanding the pathophysiology driving stress hyperglycemia-the stress response and modulation of the inflammatory process-seems to be the key to improving the care of the most critically ill and injured patients.

Obesity and Site-Specific Nosocomial Infection Risk in the Intensive Care Unit

BACKGROUND Obese patients are at higher than normal risk for postoperative infections such as pneumonia and surgical site infections, but the relation between obesity and infections acquired in the intensive care unit (ICU) is unclear. Our objective was to describe the relation between body mass index (BMI) and site-specific ICU-acquired infection risk in adults. METHODS Secondary analysis of a large, dual-institutional, prospective observational study of critically ill and injured surgical patients remaining in the ICU for at least 48 h. Patients were classified into BMI groups according to the National Heart, Lung and Blood Institute guidelines: <or= 18.5 kg/m(2) (underweight), 18.5-24.9 kg/m(2) (normal), 25-29.9 kg/m(2) (overweight), 30.0-39.9 kg/m(2) (obese), and >or= 40.0 kg/m(2) (severely obese). The primary outcomes were the number and site of ICU-acquired U.S. Centers for Disease Control and Prevention-defined infections. Multivariable logistic and Poisson regression were used to determine age-, sex-, and severity-adjusted odds ratios (ORs) and incidence rate ratios associated with differences in BMI. RESULTS A total of 2,037 patients had 1,436 infection episodes involving 1,538 sites in a median ICU length of stay of 9 days. After adjusting for age, sex, and illness severity, severe obesity was an independent risk factor for catheter-related (OR 2.2; 95% confidence interval [CI] 1.5, 3.4) and other blood stream infections (OR 3.2; 95% CI 1.9, 5.3). Cultured organisms did not differ by BMI group. CONCLUSION Obesity is an independent risk factor for ICU-acquired catheter and blood stream infections. This observation may be explained by the relative difficulty in obtaining venous access in these patients and the reluctance of providers to discontinue established venous catheters in the setting of infection signs or symptoms.

Impact of high-dose antioxidants on outcomes in acutely injured patients

BACKGROUND The profound oxidative stress that occurs following injury results in significant depletion of many endogenous antioxidants (vitamin C, E, selenium). Increasing evidence suggests antioxidant supplementation reduces infectious complications and organ dysfunction following injury and hemorrhagic shock. The purpose of this study was to evaluate the impact of high-dose antioxidant administration on the mortality rate of acutely injured patients. METHODS In October 2005, we implemented a 7-day high-dose antioxidant protocol for acutely injured patients admitted to our trauma center. A retrospective cohort study, evaluating all patients admitted to the trauma service between October 2005 and September 2006 following protocol implementation (AO+), was performed. The comparison cohort (AO-) was made up of those patients admitted in the year prior to protocol implementation. RESULTS A total of 4,294 patients met criteria (AO+, N = 2,272; AO-, N = 2022). Hospital (4 vs 3 days, P < .001) and ICU (3 vs 2 days, P = .001) median length of stays were significantly shorter in the AO+ group. Mortality was significantly lower in the AO+ group (6.1% vs 8.5%, P = .001), translating into a 28% relative risk reduction for mortality in patients exposed to high-dose antioxidants. After adjusting for age, gender, and probability of survival, AO exposure was associated with even lower mortality (OR 0.32, 95% CI 0.22-0.46). Patients with an expected survival <50% benefited most (OR 0.24, 95% CI 0.15-0.37). CONCLUSIONS A high-dose antioxidant protocol resulted in a 28% relative risk reduction in mortality and a significant reduction in both hospital and ICU length of stay. This protocol represents an inexpensive intervention to reduce mortality/morbidity in the trauma patient.

A Computerized Insulin Infusion Titration Protocol Improves Glucose Control With Less Hypoglycemia Compared to a Manual Titration Protocol in a Trauma Intensive Care Unit

BACKGROUND Previous studies reflect reduced morbidity and mortality with intensive blood glucose control in critically ill patients. Unfortunately, implementation of such protocols has proved challenging. This study evaluated the degree of glucose control using manual paper-based vs computer-based insulin protocols in a trauma intensive care unit. METHODS Of 1455 trauma admissions from May 31 to December 31, 2005, a cohort of 552 critically ill patients met study entry criteria. The patients received intensive blood glucose management with IV insulin infusions. Using Fishers exact test, the authors compared patients managed with a computerized protocol vs a paper-based insulin protocol with respect to the portion of glucose values in a target range of 80-110 mg/dL, the incidence of hyperglycemia (> or =150 mg/dL), and the incidence of hypoglycemia (< or =40 mg/dL). RESULTS Three hundred nine patients were managed with a manual paper-based protocol and 243 were managed with a computerized protocol. The total number of blood glucose values across both groups was 21,178. Mean admission glucose was higher in the computer-based protocol group (170 vs 152 mg/dL; p < .001, t-test). Despite this finding by Fishers exact test, glucose control was superior in the computerized group; a higher portion of glucose values was in range 80-110 mg/dL (41.8% vs 34.0%; p < .001), less hyperglycemia occurred (12.8% vs 15.1%; p < .001), and less hypoglycemia occurred (0.2% vs 0.5%; p < .001). CONCLUSIONS A computerized insulin titration protocol improves glucose control by (1) increasing the percentage of glucose values in range, (2) reducing hyperglycemia, and (3) reducing severe hypoglycemia.

Implementation of a Real-time Compliance Dashboard to Help Reduce SICU Ventilator-Associated Pneumonia With the Ventilator Bundle

BACKGROUND Ventilator-associated pneumonia (VAP) causes significant morbidity and mortality in critically ill surgical patients. Recent studies suggest that the success of preventive measures is dependent on compliance with ventilator bundle parameters. HYPOTHESIS Implementation of an electronic dashboard will improve compliance with the bundle parameters and reduce rates of VAP in our surgical intensive care unit (SICU). DESIGN Time series analysis of VAP rates between January 2005 and July 2008, with dashboard implementation in July 2007. SETTING Multidisciplinary SICU at a tertiary-care referral center with a stable case mix during the study period. PATIENTS Patients admitted to the SICU between January 2005 and July 2008. MAIN OUTCOME MEASURES Infection control data were used to establish rates of VAP and total ventilator days. For the time series analysis, VAP rates were calculated as quarterly VAP events per 1000 ventilator days. Ventilator bundle compliance was analyzed after dashboard implementation. Differences between expected and observed VAP rates based on time series analysis were used to estimate the effect of intervention. RESULTS Average compliance with the ventilator bundle improved from 39% in August 2007 to 89% in July 2008 (P < .001). Rates of VAP decreased from a mean (SD) of 15.2 (7.0) to 9.3 (4.9) events per 1000 ventilator days after introduction of the dashboard (P = .01). Quarterly VAP rates were significantly reduced in the November 2007 through January 2008 and February through April 2008 periods (P < .05). For the August through October 2007 and May through July 2008 quarters, the observed rate reduction was not statistically significant. CONCLUSIONS Implementation of an electronic dashboard improved compliance with ventilator bundle measures and is associated with reduced rates of VAP in our SICU.

Estradiol is associated with mortality in critically ill trauma and surgical patients

Objective:Sexual dimorphism (variation in outcome related to sex) after trauma–hemorrhage and sepsis is well documented in animals, with the pro-estrus state being proinflammatory and associated with a survival advantage. Although some observational studies confirm this pattern in humans, others demonstrate no difference in mortality. Estrogens are important modulators of the inflammatory response and insulin resistance in humans and have been linked to increased mortality during sepsis. Our objective was to determine whether sex hormone levels were associated with outcomes in critically ill surgical patients. Design:Prospective cohort. Patients:A total of 301 adult critically ill or injured surgical patients remaining in the intensive care unit for ≥48 hrs at two academic medical centers. Interventions:None. Measurements:Blood was collected 48 hrs after intensive care unit admission and assayed for sex hormones (estradiol, testosterone, prolactin, and progesterone) and cytokines (tumor necrosis factor-&agr; and interleukin-1, -2, -4, -6, -8, and -10). Demographic and outcome data were also collected. Main Results:Estradiol was significantly higher in nonsurvivors (p < .001). Analysis by quartiles of estradiol demonstrated greater than a three-fold increase in the mortality rate for the highest vs. the lowest estradiol quartiles (29% vs. 8%, p < .001). Estradiol was also higher in nonsurvivors. An estradiol level of 100 pg/mL was associated with an odds ratio for death of 4.60 (95% confidence interval, 1.56–13.0) compared with a reference estradiol level of 45 pg/mL. Conclusions:We conclude that serum estradiol correlates with mortality in critically ill and injured surgical patients and discuss potential mechanisms for this observation.

Obesity and Pulmonary Complications in Critically Injured Adults

BACKGROUND Pulmonary complications following injury significantly contribute to subsequent mortality. Obese patients have preexisting risk factors for pulmonary complications, and are at risk for these complications following elective surgery. Whether or not obesity contributes to pulmonary complications after critical injury is poorly understood. METHODS A secondary analysis of a prospective cohort study of critically injured adults requiring at least 48 h of intensive care was performed. Patients were classified into the following body mass index groups: < or = 18.5 kg/m2 (underweight); 18.5 to 24.9 kg/m2 (normal); 25 to 29.9 kg/m2 (overweight); 30.0 to 39.9 kg/m2 (obese); and > or = 40.0 kg/m2 (severely obese). Outcomes included the rates of ARDS and pneumonia, the placement of a tracheostomy tube, and in-hospital mortality rate. RESULTS A total of 1,291 patients were available for analysis, and 30% of these patients were classified as either obese or severely obese. The age-, gender-, and severity-adjusted rate of ARDS was lower in severely obese patients (odds ratio, 0.36; 95% confidence interval [CI], 0.13 to 0.99) compared to normal weight patients. The rates of pneumonia (37%), tracheostomy (10%), and in-hospital mortality (11%) did not differ among the groups. Despite no difference in pulmonary complications, the severely obese group had an ICU length of stay that was 4.8 days (95% CI, 1.8 to 7.7 days) longer than the normal weight group. CONCLUSION Obesity does not appear to be an independent risk factor for increased pulmonary complications after critical injury, but severely obese patients are likely to require longer ICU stays.