Bruno M. T. Pereira

First report on safety and efficacy of hetastarch solution for initial fluid resuscitation at a level 1 trauma center.

BACKGROUND For logistics, the US Army recommends Hextend (Hospira; 6% hetastarch in buffered electrolyte, HET) for battlefield resuscitation. To support this practice, there are laboratory data, but none in humans. To test the hypothesis that HET is safe and effective in trauma, we reviewed our first 6 months of use at a civilian level 1 trauma center. STUDY DESIGN From June 2008 to December 2008, trauma patients received standard of care (SOC) +/- 500 to 1,000 mL of HET within 2 hours of admission at surgeon discretion. Each case was reviewed, with waiver of consent. RESULTS There were 1,714 admissions; 805 received HET and 909 did not. With HET versus SOC, overall mortality was 5.2% versus 8.9% (p = 0.0035) by univariate analysis. Results were similar after penetrating injury only (p = 0.0016) and in those with severe injury, defined by Glasgow Coma Scale <9 (p = 0.0013) or Injury Severity Score >26 (p = 0.0142). After HET, more patients required ICU admission (40.9% vs. 34.5%; p = 0.0334) and transfusions of blood (34.4% vs. 20.2%; p = 0.0014) or plasma (20.7% vs. 12.2%; p = 0.0251), but there were no treatment-related differences in prothrombin time or partial thromboplastin time. The 24-hour urine outputs and requirements for blood, plasma, and other fluids were similar. However, increased early deaths with SOC implicate possible selection bias. If that factor was controlled for with multivariate analysis, the same trends were present, but the apparent treatment effects of HET were no longer statistically significant. CONCLUSIONS In the first trial to date in hemodynamically unstable trauma patients, and the largest trial to date in any population of surgical patients, initial resuscitation with HET was associated with reduced mortality and no obvious coagulopathy. A randomized blinded trial is necessary before these results can be accepted with confidence.

Heart rate variability is an independent predictor of morbidity and mortality in hemodynamically stable trauma patients.

BACKGROUND Reduced heart rate variability (HRV) reflects autonomic dysfunction and can triage patients better than routine trauma criteria or vital signs. However, there is questionable specificity and no consensus measurement technique. The purpose of this study was to analyze whether factors that alter autonomic function affect the specificity of HRV for assessing traumatic injury. METHODS We evaluated 216 hemodynamically stable adults (3:1 M:F; 97:3 blunt:penetrating; age 49 years ± 1 year, mean ± standard error) undergoing computed axial tomography (CT) scan to rule out traumatic brain injury (TBI). All were prospectively instrumented with a Mars Holter system (GE Healthcare, Milwaukee, WI). HRV was determined offline using time domain (standard deviation of normal-normal intervals, root-mean-square successive difference) and frequency domain (very low frequency [VLF], LF, wideband frequency, high frequency [HF], low to HF index ratio) calculations from 15-minute electrocardiogram and correlated with routine vital signs, mortality, TBI, morbidity, length of stay (LOS), and comorbidities. Significance (p ≤ 0.05) was determined using nonparametric analysis, Students t test, analysis of variance, or multiple logistic regression. RESULTS VLF alone predicted survival, severity of TBI, intensive care unit LOS, and hospital LOS (all p < 0.05). Beta-blockers or diabetes had no effect, whereas age, sedation, mechanical ventilation, spinal cord injury, and intoxication influenced one or more of the variables with age being the most powerful confounder (all p < 0.05). Except for the Glasgow Coma Scale, no other routine trauma or hemodynamic criteria correlated with any of these outcomes. CONCLUSIONS Decreased VLF is an independent predictor of mortality and morbidity in hemodynamically stable trauma patients. Other time and other frequency domain variables correlated with some, but not all, outcomes. All were heavily influenced by factors that alter autonomic function, especially patient age.

Predeployment Mass Casualty and Clinical Trauma Training for Us Army Forward Surgical Teams

Since the beginning of the program in 2002, 84 Forward Surgical Teams (FSTs) have rotated through the Army Trauma Training Center (ATTC) at the University of Miami/Ryder Trauma Center including all those deployed to Iraq and Afghanistan. The purpose of this study was to provide the latest updates of our experience with FSTs at the ATTC. Before deployment, each FST participates in a 2-week training rotation at the ATTC. The rotation is divided into 3 phases. Phase 1 is to refresh FST knowledge regarding the initial evaluation and management of the trauma patient. Phase 2 is the clinical phase and is conducted entirely at the Ryder Trauma Center. The training rotation culminates in phase 3, the Capstone exercise. During the Capstone portion of their training, the entire 20-person FST remains at the Ryder Trauma Center and is primarily responsible for the evaluation and resuscitation of all patients arriving over a 24-hour period. Subject awareness concerning their role within the team improved from 71% to 95%, indicating that functioning as a team in the context of the mass casualty training exercise along with clinical codes was beneficial. The clinical component of the rotation was considered by 47% to be the most valuable aspect of the training. Our experience strongly suggests that a multimodality approach is beneficial for preparing a team of individuals with minimal combat (or trauma) experience for the rigors of medical care and triage on the battlefield. The data provided by participants rotating through the ATTC show that through clinical exposure and simulation over a 2-week period, FST performance is optimized by defining provider roles and improving communication. The mass casualty training exercise is a vital component of predeployment training that participants feel is valuable in preparing them for the challenges that lay ahead.

Penetrating Cardiac Injuries: A Historic Perspective and Fascinating Trip Through Time

ardiac injuries have been described since ancient times. he earliest known descriptions of cardiac injuries appear n Homer’s Iliad(Fig. 1). It contains specific references to xsanguination as a cause of death and foreign bodies imaled in the heart. The poetic description of the death of arpedon includes an episode of exsanguinating hemorhage from a cardiac injury, “Not so Patroclus’ never erring arts; Aim’d at his breast, it peers at the mortal part, Where he strong fibers bind the solid heart.” The Iliad also records an observation describing the ardiac impulse transmitted through a spear that had transixed the heart of Alkathoos, “The hero Idomeneus smote im in the midst of the breast with the spear. . . and he fell ith a crash, and the lance fixed in his heart that, still eating, shook the butt end of the spear.” Beck classified the history of wounds of the heart acording to three historical periods. First, the period of mysicism, in which wounds to the heart were described, but ere considered uniformly fatal. This was followed by a eriod of observation and experiment, culminating in the eriod of suture, which began in 1882. Hippocrates stated hat all wounds of the heart were deadly. Authors such as vid, Celsus, Pliny, Aristotle, and Galen regarded hem as absolutely and necessarily fatal. According to Ar-

Bispectral index to monitor propofol sedation in trauma patients

BACKGROUND This study tested the hypothesis that the bispectral index (BIS) is reliable relative to clinical judgment for estimating sedation level during daily propofol spontaneous awakening trials (SATs) in trauma patients. METHODS This was a prospective observational trial with waiver of consent conducted in the intensive care unit of Level I trauma center in 94 mechanically ventilated trauma patients sedated with propofol alone or in combination with midazolam. BIS, Richmond Agitation Sedation Scale (RASS), electromyography, and heart rate variability, as a test of autonomic function, were measured for 45 minutes during daily SATs. Data were evaluated with analysis of variance, linear regression, and nonparametric tests. RESULTS The BIS wave form coincided almost exactly with propofol on/off. Steady-state BIS correlated with RASS (p < 0.0001) and with propofol dose (p < 0.0001), but the strengths of association were relatively low (all r(2) < 0.5). BIS wave form was not altered by age, heart rate, or heart rate variability and was similar with propofol alone or propofol plus midazolam, but the presence of brain injury or the use of paralytics shifted the curve downward (both p < 0.001). The overall test characteristics for BIS versus RASS without neuromuscular blockade were sensitivity: 90% versus 77% (p = 0.034); specificity: 90% versus 75% (p = 0.021); positive predictive value: 90% versus 76% (p = 0.021), and negative predictive value: 90% versus 76% (p = 0.021). CONCLUSIONS In the first trial in trauma patients and largest trial in any surgical population, the (1) BIS was reliable and has advantages over RASS of being continuous and objective, at least during a propofol SAT; (2) BIS interpretation remains somewhat subjective in patients receiving paralytic agents or with traumatic brain injury.

Landmark Central Venous Catheterization is Effective but Ultrasound Helps Even in Experienced Hands

Introduction: A recent report published by the American Society of Anesthesiologists (ASA) task force on central venous access suggests the use of real time ultrasound for placing central venous lines. As in our center there is no ultrasound device specific for this purpose, a decision to test the hypothesis whether anatomic landmark for central venous catheterization is effective in experienced hands was made. Methods: A retrospective review of a prospectively collected database was performed for the period January 2002 to June 2013. Five hundred fifty patients underwent long-term central venous catheter placement. All procedures were performed by experienced (>50 placements) surgeons utilizing standard techniques. Results: Males slightly predominated, corresponding to 51.3% (n=282) of the total population. The most frequent cannulated vein was the subclavian vein (n=451/82%). The Right Subclavian Vein (RSV) was the first choice for catheterization (n=410/74.5%). 83.5% (n=459) of the punctures were successful on the first attempt. Complications included arterial puncture (n=36/6.5%), hematoma (n=16/2.9%) and pneumothorax (n=4/0.7%). Ultrasound was used in selective high-risk cases (7.3%). Conclusion: The data suggests that with proper skill and experience, landmark anatomic position is effective for central venous catheterization, however ultrasound is helpful in specific difficult cases.