Antioxidant supplementation and atrial arrhythmias in critically ill trauma patients.

Background: The purpose of this study is to determine if antioxidant supplementation influences the incidence of atrial arrhythmias in trauma intensive care unit (ICU) patients.

Materials And Methods: In this retrospective pre-post study, critically ill injured patients aged ≥18 years, admitted to a single-center trauma ICU for ≥48 hours were eligible for inclusion. The control group consists of patients admitted from January 2000 to September 2005, before routine antioxidant supplementation in our ICU.

Insulin Resistance in Critically Injured Adults: Contribution of Pneumonia, Diabetes, Nutrition, and Acuity.

Purpose: Changes in insulin resistance (IR) cause stress-induced hyperglycemia after trauma, but the numerous factors involved in IR have not been delineated clearly. We hypothesized that a statistical model could help determine the relative contribution of different clinical co-variates to IR in critically injured patients.

Patients And Methods: We retrospectively studied 726 critically injured patients managed with a computer-assisted glycemic protocol at an academic level I trauma center (639 ventilated controls without pneumonia (VWP) and 87 patients with ventilator-associated pneumonia (VAP).

A pilot study of the noninvasive assessment of the lung microbiota as a potential tool for the early diagnosis of ventilator-associated pneumonia.

Background: Ventilator-associated pneumonia (VAP) remains a common complication in critically ill surgical patients, and its diagnosis remains problematic. Exhaled breath contains aerosolized droplets that reflect the lung microbiota. We hypothesized that exhaled breath condensate fluid (EBCF) in hygroscopic condenser humidifier/heat and moisture exchanger (HCH/HME) filters would contain bacterial DNA that qualitatively and quantitatively correlate with pathogens isolated from quantitative BAL samples obtained for clinical suspicion of pneumonia.

Do models incorporating comorbidities outperform those incorporating vital signs and injury pattern for predicting mortality in geriatric trauma?

Background: Geriatric trauma is becoming a significant public health concern. The most commonly used prediction models for mortality benchmarking are based on vital signs and injury pattern, including the Trauma and Injury Severity Score (TRISS), which is less accurate in the elderly. The ICD-9-based prediction models incorporating injuries and comorbidities, such as the University Health System Consortium Expected Mortality (UHC-EM), may be more accurate for the elderly.

Decreasing adrenergic or sympathetic hyperactivity after severe traumatic brain injury using propranolol and clonidine (DASH After TBI Study): study protocol for a randomized controlled trial.

Background: Severe TBI, defined as a Glasgow Coma Scale ≤ 8, increases intracranial pressure and activates the sympathetic nervous system. Sympathetic hyperactivity after TBI manifests as catecholamine excess, hypertension, abnormal heart rate variability, and agitation, and is associated with poor neuropsychological outcome. Propranolol and clonidine are centrally acting drugs that may decrease sympathetic outflow, brain edema, and agitation.

Non-invasive detection of pulmonary pathogens in ventilator-circuit filters by PCR.

Ventilator associated pneumonia is a common and costly complication in critically ill and injured surgical patients. The diagnosis of pneumonia remains problematic and non-specific. Using clinical criteria, a diagnosis of pneumonia is typically not made until an infection is well established.

Provision of balanced nutrition protects against hypoglycemia in the critically ill surgical patient.

Background: Intensive insulin therapy lowers blood glucose and improves outcomes but increases the risk of hypoglycemia. Typically, insulin protocols require a dextrose solution to prevent hypoglycemia. The authors hypothesized that the provision of balanced nutrition (enteral nutrition [EN] or parenteral nutrition [PN]) would be more protective against hypoglycemia (≤50 mg/dL) than carbohydrate alone.

Colon anastomosis after damage control laparotomy: recommendations from 174 trauma colectomies.

Background: Primary colonic anastomosis in trauma patients has been demonstrated to be safe. However, few studies have investigated this in the setting of damage control laparotomy. We hypothesized that colonic anastomosis for trauma patients requiring an open abdomen (OA) would have a higher anastomotic leak (AL) rate when compared with patients having an immediate abdominal closure following trauma laparotomy.

Increasing blood glucose variability heralds hypoglycemia in the critically ill.

Background: Control of hyperglycemia improves outcomes, but increases the risk of hypoglycemia. Recent evidence suggests that blood glucose variability (BGV) is more closely associated with mortality than either isolated or mean BG. We hypothesized that differences in BGV over time are associated with hypoglycemia and can be utilized to estimate risk of hypoglycemia (<50 mg/dL).

Trends in estradiol during critical illness are associated with mortality independent of admission estradiol.

Background: We have previously demonstrated that elevated serum estradiol (E(2)) at intensive care unit (ICU) admission is associated with death in the critically ill, regardless of sex. However, little is known about how changes in initial E(2) during the course of care might signal increasing patient acuity or risk of death. We hypothesized that changes from baseline serum E(2) during the course of critical illness are more strongly associated with mortality than a single E(2) level at admission.

Core temperature variation is associated with heart rate variability independent of cardiac index: a study of 278 trauma patients.

Purpose: The purpose of this study is to determine if temperature extremes are associated with reduced heart rate variability (HRV) and "cardiac uncoupling."

Materials And Methods: This was a retrospective, observational cohort study performed on 278 trauma intensive care unit admissions that had continuous HR, cardiac index (CI), and core temperature data from "thermodilution" Swan-Ganz catheter. Dense (captured second-by-second) physiologic data were divided into 5-minute intervals (N = 136 133; 11 344 hours of data).

Systems initiatives reduce healthcare-associated infections: a study of 22,928 device days in a single trauma unit.

Background: "Implementation research" promotes the systematic conversion of evidence-based principles into routine practice to improve the quality of care. We hypothesized a system-based initiative to reduce nosocomial infection would lower the incidence of ventilator-associated pneumonia (VAP), urinary tract infection (UTI), and bloodstream infection (BSI).

Methods: From January 2006 to April 2008, 7,364 adult trauma patients were admitted, of which 1,953 (27%) were admitted to the trauma intensive care unit and comprised the study group.

Personalized medicine: genetic variation and loss of physiologic complexity are associated with mortality in 644 trauma patients.

Objective: Personalized medicine merges genetics, physiology, and patient outcome. Loss of physiologic complexity (heart rate [HR] variability) is a bedside biomarker for autonomic nervous system (ANS) dysfunction. We hypothesized that variability in ANS receptor proteins (genetics) and loss of complexity (physiology) are independently associated with mortality in critical illness.

Early loss of heart rate complexity predicts mortality regardless of mechanism, anatomic location, or severity of injury in 2178 trauma patients.

Background: Reduced heart rate (HR) complexity (e.g., a lack of randomness or unpatterned variability) is an established predictor of trauma patient mortality.

Genetic variation in the autonomic nervous system affects mortality: a study of 1,095 trauma patients.

Background: We have previously demonstrated an unappreciated link between the autonomic nervous system and mortality, heart rate variability, and physiologic complexity.

Study Design: Genetic variation in adrenergic receptors or key enzymes in catecholamine degradation could be associated with, and potentially explain, autonomic nervous system dysfunction and its impact on mortality after severe trauma. Three genetic polymorphisms critical to the adrenergic pathway were evaluated: beta-2 adrenergic receptor (ADBR2: Q27E), alpha-1a adrenergic receptor (ADRA1A:R347C), and catechol-O-methyl transferase (COMT: V158M).

Genetic variation in complement component 2 of the classical complement pathway is associated with increased mortality and infection: a study of 627 patients with trauma.

Background: Trauma is a disease of inflammation. Complement Component 2 (C2) is a protease involved in activation of complement through the classical pathway and has been implicated in a variety of chronic inflammatory diseases. We hypothesized that genetic variation in C2 (E318D) identifies a high-risk subgroup of patients with trauma reflecting increased mortality and infection (ventilator-associated pneumonia [VAP]).

Cardiac uncoupling and heart rate variability are associated with intracranial hypertension and mortality: a study of 145 trauma patients with continuous monitoring.

Background: A noninvasive tool reflecting intracranial hypertension (ICH) should prompt early invasive monitoring and reduce secondary injury after traumatic brain injury. We hypothesized that integer heart rate variability (HRV) may be associated with rises in intracranial pressure (ICP); changes in HRV may precede changes in ICP; and both increases in ICP and cardiac uncoupling (low HRV) predict mortality.

Methods: Of 14,330 consecutive trauma admissions, 291 of these patients had an injury requiring intracranial monitoring.

Heart rate multiscale entropy at three hours predicts hospital mortality in 3,154 trauma patients.

Complexity is a measure of variation and randomness potentially indicating improvement or deterioration in critically ill patients. Previously, we have shown integer heart rate (HR) multiscale entropy (MSE), an indicator of complexity, predicts death based on long duration (12 h) and dense (>or=0.4 Hz) windows of HR data.

Beta-blocker exposure in patients with severe traumatic brain injury (TBI) and cardiac uncoupling.

Background: Cardiac uncoupling and reduced heart rate (HR) variability are associated with increased mortality after severe traumatic brain injury (TBI). Recent data has shown beta-blocker (betaB) exposure is associated with improved survival in this patient population. The purpose of the present study was to evaluate the effect of betaB exposure on the mortality risk of patients with severe TBI and early cardiac uncoupling.

Specific polymorphic variation in the mitochondrial genome and increased in-hospital mortality after severe trauma.

Objective: To determine whether specific genetic variations in the mtDNA that impact energy production and free-radical generation are potential new risk factors for in-hospital mortality after severe trauma.

Summary Background Data: Each of the 3 mitochondrial DNA polymorphisms selected for this study (at positions 4216, 10398, 4917) alter the amino acid sequence of different key subunits of Complex I in the electron transport chain. They have been previously implicated in phenotypes involving tissues with high-energy demand, such as the brain and retina.

Adrenal insufficiency, heart rate variability, and complex biologic systems: a study of 1,871 critically ill trauma patients.

Background: Reduction in integer heart rate variability (HRVi), one potential measurement of complex biologic systems, is common in ICU patients and is strongly associated with hospital mortality. Adrenal insufficiency (AI) and reduced HRVi are associated with autonomic dysfunction. Failure of the autonomic nervous system can be associated with loss of biologic complexity.

Cardiac uncoupling and heart rate variability stratify ICU patients by mortality: a study of 2088 trauma patients.

Objective: We have previously shown that cardiac uncoupling (reduced heart rate variability) in the first 24 hours of trauma ICU stay is a robust predictor of mortality. We hypothesize that cardiac uncoupling over the entire ICU stay independently predicts mortality, reveals patterns of injury, and heralds complications.

Methods: A total of 2088 trauma ICU patients satisfied the inclusion criteria for this study.

Reduced heart rate variability: an indicator of cardiac uncoupling and diminished physiologic reserve in 1,425 trauma patients.

Background: Measurements of a patient's physiologic reserve (age, injury severity, admission lactic acidosis, transfusion requirements, and coagulopathy) reflect robustness of response to surgical insult. We have previously shown that cardiac uncoupling (reduced heart rate variability, HRV) in the first 24 hours after injury correlates with mortality and autonomic nervous system failure. We hypothesized: Deteriorating physiologic reserve correlates with reduced HRV and cardiac uncoupling.

Volatility: a new vital sign identified using a novel bedside monitoring strategy.

Background: SIMON (Signal Interpretation and Monitoring) monitors and archives continuous physiologic data in the ICU (HR, BP, CPP, ICP, CI, EDVI, SVO2, SPO2, SVRI, PAP, and CVP). We hypothesized: heart rate (HR) volatility predicts outcome better than measures of central tendency (mean and median).

Methods: More than 600 million physiologic data points were archived from 923 patients over 2 years in a level one trauma center.

Surgical adverse events, risk management, and malpractice outcome: morbidity and mortality review is not enough.

Objective: To review all admissions (age > 13) to three surgical patient care centers at a single academic medical center between January 1, 1995, and December 6, 1999, for significant surgical adverse events.

Summary Background Data: Little data exist on the interrelationships between surgical adverse events, risk management, malpractice claims, and resulting indemnity payments to plaintiffs. The authors hypothesized that examination of this process would identify performance improvement opportunities overlooked by standard medical peer review; the risk of litigation would be constant across the three homogeneous patient care centers; and the risk management process would exceed the performance improvement process.