Evaluating the Utility of High Sensitivity Troponin in Blunt Cardiac Injury.

INTRODUCTION: Screening for blunt cardiac injury (BCI) includes obtaining a serum troponin level and an electrocardiogram for patients diagnosed with a sternal fracture. Our institution has transitioned to the use of a high sensitivity troponin I (hsTnI). The aim of this study was to determine whether hsTnI is comparable to troponin I (TnI) in identifying clinically significant BCI. MATERIALS AND METHODS: Trauma patients presenting to a level I trauma center over a 24-mo period with the diagnosis of sternal fracture were screened for BCI. Any initial TnI more than 0.04 ng/mL or hsTnI more than 18 ng/L was considered positive for potential BCI. Clinically significant BCI was defined as a new-bundle branch block, ST wave change, echocardiogram change, or need for cardiac catheterization. RESULTS: Two hundred sixty five patients with a sternal fracture were identified, 161 underwent screening with TnI and 104 with hsTnI. For TnI, the sensitivity and specificity for detection of clinically significant BCI was 0.80 and 0.79, respectively. For hsTnI, the sensitivity and specificity for detection of clinically significant BCI was 0.71 and 0.69, respectively. A multivariate analysis demonstrated the odds ratio for significant BCI with a positive TnI was 14.4 (95% confidence interval, 3.9-55.8, P < 0.0001) versus an odds ratio of 5.48 (95% confidence interval 1.9-15.7, P = 0.002) in the hsTnI group. CONCLUSIONS: The sensitivity of hsTnI is comparable to TnI for detection of significant BCI. Additional investigation is needed to determine the necessity and interval for repeat testing and the need for additional diagnostic testing.

Assessment of Detectable Serum Tobramycin Concentrations in Patients Receiving Inhaled Tobramycin for Ventilator-Associated Pneumonia.

BACKGROUND: Inhaled tobramycin can be used for empiric or definitive therapy of ventilator-associated pneumonia (VAP) in mechanically ventilated patients. This is believed to minimize systemic exposure and potential adverse drug toxicities including acute kidney injury (AKI). However, detectable serum tobramycin concentrations have been reported after inhaled tobramycin therapy with AKI. METHODS: This retrospective, observational study evaluated mechanically ventilated adult subjects admitted to ICUs at a large, urban academic medical center that received empiric inhaled tobramycin for VAP. Subjects were separated into detectable (ie, ≥ 0.6 mg/L) or undetectable serum tobramycin concentration groups, and characteristics were compared. Independent predictors for detectable serum tobramycin concentration and new onset AKI during or within 48 h of therapy discontinuation were assessed. RESULTS: Fifty-nine inhaled tobramycin courses in 53 subjects were included in the analysis, of which 39 (66.1%) courses administered to 35 (66.0%) subjects had detectable serum tobramycin concentrations. Subjects with detectable serum tobramycin concentrations were older (57.1 y ± 11.4 vs 45.9 ±15.0, P = .004), had higher PEEP (9.2 cm H2O [7.0-11.0] vs 8.0 [5.6-8.9], P = .049), chronic kidney disease stage ≥ 2 (10 [29.4%] vs 0 [0%], P = .009), and higher serum creatinine before inhaled tobramycin therapy (1.26 mg/dL [0.84-2.18] vs 0.76 [0.47-1.28], P = .004). Age (odds ratio 1.09 [95% CI 1.02-1.16], P = .009) and PEEP (odds ratio 1.47 [95% CI 1.08-2.0], P =.01) were independent predictors for detectable serum tobramycin concentration. Thirty-seven subjects had no previous renal disease or injury, of which 9 (24.3%) developed an AKI. Sequential Organ Failure Assessment score (odds ratio 1.72 [95% CI 1.07-2.76], P = .03) was the only independent predictor for AKI. CONCLUSIONS: Detectable serum tobramycin concentrations were frequently observed in critically ill, mechanically ventilated subjects receiving empiric inhaled tobramycin for VAP. Subject age and PEEP were independent predictors for detectable serum tobramycin concentration. Serum monitoring and empiric dose reductions should be considered in older patients and those requiring higher PEEP.

Retrospective Evaluation of Venous Thromboembolism Prophylaxis in Elderly, High-Risk Trauma Patients.

BACKGROUND: Venous thromboembolism (VTE) risk increases with age. Scarce data exist for patients age ≥65 y. This study evaluated VTE incidence in elderly, high-risk trauma patients receiving unfractionated heparin (UFH) or enoxaparin chemoprophylaxis. MATERIALS AND METHODS: This retrospective, single-center, cohort study included trauma patients age ≥ 65 y with risk assessment profile (RAP) ≥ 5 who received UFH or enoxaparin chemoprophylaxis. The primary outcome was VTE incidence requiring therapeutic anticoagulation. An age-modified RAP (RAP-AM) was calculated as RAP without age distribution points. Logistic regression analyses were performed to identify independent predictors for VTE development and chemoprophylactic agent selection. Bleeding incidence compared packed red blood cells utilized. RESULTS: A total of 1090 patients were included (UFH, n = 655; enoxaparin, n = 435). VTE occurred in 39 (3.6%) patients with no difference between groups in proximal deep vein thrombosis (2.1% versus 3.0%, P = 0.52) or pulmonary embolism (1.2% versus 1.4%, P = 0.96). Weight ≥125 kg (OR 4.12, 95% CI 1.06-16.11) and RAP-AM ≥ 5 (OR 6.52, 95% CI 2.65-16.03) were independently associated with VTE development. Increasing age (OR 1.04, 95% CI 1.03-1.06), initiation ≤ 24 h (OR 2.17, 95% CI 1.66-2.84) and creatinine clearance ≤ 30 mL/min (OR 1.61, 95% CI 1.17-2.21) were independent predictors of receiving UFH whereas increasing ISS (OR 0.97, 95% CI 0.95-0.99) was associated with receiving enoxaparin. CONCLUSIONS: VTE incidence may be similar for high-risk, elderly trauma patients receiving UFH and enoxaparin chemoprophylaxis. Further research is necessary to determine noninferiority of UFH to enoxaparin in this patient population.

Accuracy of noninvasive hemoglobin monitoring in patients at risk for hemorrhage.

BACKGROUND: Monitoring for acute blood loss is critical in surgical patients, and delays in identifying hemorrhage can result in poor outcomes. The current standard of care for monitoring patients at risk for bleeding is serial measurement of hemoglobin (Hgb) by standard laboratory complete blood count (CBC). Point-of-care testing (i.e., iSTAT) can be a rapid method of evaluating Hgb, and spectrophotometry-based devices (i.e., Radical-7) offer the advantages of being continuous and noninvasive. We sought to evaluate the accuracy of Radical-7 and iSTAT in measuring Hgb and assessing for blood loss when compared with the criterion standard CBC. METHODS: Adult patients at risk for hemorrhage admitted to the surgical intensive care unit of a tertiary referral, Level I trauma center were eligible for this study. Serial CBC Hgb measurements were drawn as clinically indicated. The Radical-7 device was placed on the patient for noninvasive Hgb measurements (SpHb), and at each CBC measurement, concurrent iSTAT Hgb measurements were obtained. Bland-Altman analysis was used to compare the three methods of measuring Hgb with accuracy defined as measurements within 1.0-g/dL CBC Hgb. Concordance measurements were also performed to compare trends between values. RESULTS: Eighty-eight patients were enrolled and underwent 572 CBC measurements. Bland-Altman analysis of SpHb versus CBC resulted in an estimated bias of 1.49 g/dL, with 95% limits of agreement of -2.2 g/dL to 5.0 g/dL. iSTAT versus CBC resulted in an estimated bias of -0.63 g/dL, with 95% limits of agreement of -3.4 g/dL to 2.2 g/dL. Changes in SpHb had concordance with CBC Hgb 60% of the time, compared with 76% for iSTAT versus CBC CONCLUSION: Radical-7 SpHb was inaccurate when compared with CBC Hgb levels, and serial SpHb achieved concordance with CBC Hgb 60% of the time. As such, the clinical utility of Radical-7 as a rapid, noninvasive predictor of acute hemorrhage may be limited. LEVEL OF EVIDENCE: Diagnostic study, level II; care management, level III.

A practical approach to the use of prone therapy in acute respiratory distress syndrome.

In this article we propose a practical approach to the use of prone therapy for acute respiratory distress syndrome (ARDS). We have attempted to provide information to improve the understanding and implementation of prone therapy based on the literature available and our own experience. We review the basic physiology behind ARDS and the theoretical mechanism by which prone therapy can be of benefit. The findings of the most significant studies regarding prone therapy in ARDS as they pertain to its implementation are summarized. Also provided is a discussion of the nuances of utilizing prone therapy, including potential pitfalls, complications, and contraindications. The specific considerations of prone therapy in open abdomens and traumatic brain injuries are discussed as well. Finally, we supply suggested protocols for the implementation of prone therapy discussing criteria for initiation and cessation of therapy as well as addressing issues such as the use of neuromuscular blockade and nutritional supplementation.

Early treatment of blunt cerebrovascular injury with concomitant hemorrhagic neurologic injury is safe and effective.

BACKGROUND: Early pharmacologic treatment for blunt cerebrovascular injury (BCVI) is often withheld when concomitant traumatic brain injury or cervical spinal cord injury occurs. This study examines the safety and efficacy of early treatment for patients with both BCVI and traumatic neurologic injury (TNI). METHODS: Ten-year retrospective review of patients with BCVI and a TNI was performed. Stroke outcomes for those treated with pharmacologic therapy for their BCVI were compared with those not treated. In addition, the likelihood of worsening of TNI was determined for those exposed to pharmacologic therapy compared with those not exposed. Multivariate logistic regression techniques were used to analyze adjusted odds ratio for stroke risk. RESULTS: Seventy-seven patients were identified with BCVI + TNI. Strokes occurred in 27% patients with 3 of 21 (14%) strokes present at arrival. There were no differences in baseline characteristics between groups. Stroke rate was higher in the untreated group compared with treated (57% vs. 4%, p < 0.0001). On multivariate regression, treatment status was the most significant stroke predictor (adjusted odds ratio 4.4, 3.0-6.5, p < 0.0001, c-stat 0.93). There was no difference in risk of hemorrhagic deterioration of traumatic brain injury based on pharmacologic exposure versus no exposure (5% vs. 6%, p = 0.6). Likewise, no patient with spinal cord injury worsened as a result of pharmacologic exposure. Of the potentially preventable strokes, 24% (4 of 17) resulted in a stroke-related death and all four deaths occurred in the untreated group. CONCLUSION: The benefit of early treatment for BCVI markedly outweighs the risk of treatment for patients suffering concomitant BCVI and hemorrhagic neurologic injury. LEVEL OF EVIDENCE: : III.

Development of a novel method of progressive temporary abdominal closure.

BACKGROUND: This paper describes our experience with a novel method of temporary abdominal closure that permits frequent reassessment of the abdominal contents and progressive reapproximation of the fascial edges without compromising definitive fascial closure outcomes. METHODS: We developed a novel method of temporary abdominal closure, which we have named the frequent assessment temporary abdominal closure (FASTAC). The records of patients who underwent planned relaparotomy during 5 years were reviewed. The data collected included patient demographics, indication for operation, number of operations, duration of temporary abdominal closure placement, hospital duration of stay, method of definitive abdominal closure, and subsequent ventral hernia repair. RESULTS: One hundred and thirty-three patients underwent 308 temporary abdominal closure placements, including 16 patients who had a FASTAC placed for open abdomen management. FASTAC remained in place for a significantly greater time with more frequent reassessment. Fascial closure techniques were not different in FASTAC patients. FASTAC patients had a significantly greater duration of stay, which suggests selective placement in a more complicated patient population. The materials for frequent assessment temporary abdominal closure cost only $38 compared with $350 for a large piece of Silastic. CONCLUSION: FASTAC is a novel, cost-effective method of temporary abdominal closure that allows for frequent bedside intra-abdominal surveillance, maintains abdominal domain, and does not compromise abdominal closure outcomes in the management of the open abdomen.

Emergency airway placement by EMS providers: comparison between the King LT supralaryngeal airway and endotracheal intubation.

INTRODUCTION: The ever-present risk of mass casualties and disaster situations may result in airway management situations that overwhelm local emergency medical services (EMS) resources. Endotracheal intubation requires significant user education/training and carries the risk of malposition. Furthermore, personal protective equipment (PPE) required in hazardous environments may decrease dexterity and hinder timely airway placement. Alternative airway devices may be beneficial in these situations. OBJECTIVE: The objective of this study was to evaluate the time needed to place the King LT Supralaryngeal Airway compared to endotracheal intubation when performed by community EMS personnel with and without PPE. METHODS: Following training, 47 EMS personnel were timed placing both endotracheal tubes and the King LT supralaryngeal airway in a simulator mannikin. The study participants then repeated this exercise wearing PPE. RESULTS: The EMS personnel wearing PPE took significantly longer to place an endotracheal tube than they did without protective equipment (53.4 seconds and 39.5 seconds, p <0.002). The time to place the King LT was significantly faster than the placement of the endotracheal tube without protective equipment (18.4 seconds and 39.5 seconds, respectively, p <0.00003). There also were statistically significant differences between the time required to place the King LT and endotracheal tube in EMS personnel wearing protective equipment (19.7 seconds and 53.4 seconds, p <0.000007). CONCLUSIONS: The King LT Supralaryngeal Airway device may be advantageous in prehospital airway management situations involving multiple patients or hazardous environments. In this study, its insertion was faster than endotracheal intubation when performed by community EMS providers.

Risk factors for relapse of ventilator-associated pneumonia in trauma patients.

BACKGROUND: Our goal was to define risk factors for ventilator-associated pneumonia (VAP) relapse and examine the implications, if any, for initial therapy in trauma patients. METHODS: Trauma patients cared for in the surgical intensive care unit during a 48-month period with confirmed VAP recurrence were evaluated. Recurrent VAP was defined as a positive quantitative culture (> or = 10(4) colony-forming units/mL in a bronchoalveolar lavage or protected catheter lavage specimen) > or = 4 days after initiation of antibiotics for the primary episode. Recurrence with at least one of the initial causative pathogens was defined as a relapse. Initial causal pathogen, Acute Physiology and Chronic Health Evaluation II score, injury severity score, Glasgow Coma Score (GCS), age, white blood cell count (WBC), and duration of hospital stay before diagnosis were analyzed in univariate and multivariate regression models. RESULTS: A total of 55 patients met the criteria of recurrent VAP. Of these 55 recurrences, 19 (35%) were relapses. Acute Physiology and Chronic Health Evaluation II score, injury severity score, and GCS were not associated with VAP relapse by univariate analyses. Patients who relapsed had primary VAP involving nonfermenting gram-negative bacilli (NFGNB) (Acinetobacter, Pseudomonas, and Stenotrophomonas species) more frequently than other organisms (68% vs. 32%, p = 0.001). Primary VAP with NFGNB was found to be a significant predictor of VAP relapse by univariate and multivariate logistic regression analysis (OR = 5.1, p = 0.003; OR = 4.63, p = 0.005, respectively). CONCLUSIONS: There is a high rate of VAP relapse associated with primary infection by NFGNB, suggesting initial treatment failure. Trauma patients with primary VAP involving these organisms may benefit from increased surveillance for relapse.

Close is dead: determinants of firearm injury lethality in women.

BACKGROUND: Accurate data regarding intimate partner violence is difficult to obtain, particularly when examining only homicides or trauma registries. This study characterizes firearm violence against women by examining data from both the county coroner and an urban level I trauma center. METHODS: The Trauma Registry and Coroners database were reviewed for female victims of firearm assault from 1998 to 2006. Data collected included age, race, location of assault (home, public, unknown), mortality, and injuries. Assailants were categorized as intimate partners (IP), acquaintances, strangers, or undetermined. Adjusted odds ratios for effects of assailant and location were calculated using logistic regression analysis, with statistical significance at alpha = 0.05. RESULTS: Of 115 victims identified, 51 (44%) were fatally injured. Forty-two (37%) of assailants were IP. Fatalities occurred in 71% of IP, 50% of acquaintance, and 20% of stranger assaults. Firearm assault by IP was 10 times more lethal than injury by stranger (p < 0.0005). Assaults at home occurred 54% of the time and had 60% mortality. Assault at home was 3.8 times more lethal than assault in public (p < 0.002). Seventy-nine percent of IP assaults, 63% of acquaintance assaults, and 29% of stranger assaults occurred in the home. In 99 victims with documented injuries, head injuries were found in 68% of IP assaults, compared with 33% and 16% of acquaintance and stranger assaults. CONCLUSION: IP firearm assaults against women may be underrepresented in current databases. These assaults are highly lethal, frequently occur at home, and often involve head injury. These observations may lend to strategies for trauma prevention.

The devil is in the details: maximizing revenue for daily trauma care.

BACKGROUND: Falling reimbursement rates for trauma care demand a concerted effort of charge capture for the fiscal survival of trauma surgeons. We compared current procedure terminology code distribution and billing patterns for Subsequent Hospital Care (SHC) before and after the institution of standardized documentation. METHODS: Standardized SHC progress notes were created. The note was formulated with an emphasis on efficiency and accuracy. Documentation was completed by residents in conjunction with attendings following standard guidelines of linkage. Year-to-year patient volume, length of stay (LOS), injury severity, bills submitted, coding of service, work relative value units (wRVUs), revenue stream, and collection rate were compared with and without standardized documentation. RESULTS: A 394% average revenue increase was observed with the standardization of SHC documentation. Submitted charges more than doubled in the first year despite a 14% reduction in admissions and no change in length of stay. Significant increases in level II and level III billing and billing volume (P < .05) were sustainable year to year and resulted in an average per patient admission SHC income increase from $91.85 to $362.31. CONCLUSIONS: Use of a standardized daily progress note dramatically increases the accuracy of coding and associated billing of subsequent hospital care for trauma services.

An analgesia-delirium-sedation protocol for critically ill trauma patients reduces ventilator days and hospital length of stay.

BACKGROUND: Analgesics and sedatives are required to maintain a calm and comfortable mechanically ventilated injured patient. Continuous sedative infusions have been shown to lengthen mechanical ventilation and hospital length of stay. Daily interruption of sedative infusions may reduce both of these variables. Implementation of an Analgesia-Delirium-Sedation (ADS) Protocol using objective assessments with a goal of maintaining an awake and comfortable patient may obviate the need for daily interruption of infusions in critically ill trauma patients. We examined the effects of such a protocol on ventilator duration, intensive care unit (ICU) length of stay, hospital slength of stay, and medication requirements. METHODS: A multidisciplinary team designed the protocol. Objective measures of pain (visual/objective pain assessment scale-VAS/OPAS), agitation (Richmond Agitation-Sedation Scale-RASS), and delirium [Confusion Assessment Method {CAM-ICU}] were used. Medications were titrated to a RASS of -1 to +1 and VAS/OPAS <4. Haloperidol was used to treat delirium in CAM-ICU positive patients. Retrospective review of the local Project IMPACT database for a 6-month period in 2004 was compared with the same seasonal period in 2006 in which the ADS protocol was used. All mechanically ventilated trauma patients receiving infusions of narcotic, propofol, or benzodiazepine were included. Age, APACHE II score, Injury Severity Score, ventilator days, ventilator-free days at day 28, ICU length of stay, and hospital length of stay are reported as median values (interquartile range). Medication usage is reported as mean values (+/-SD). Differences in data were analyzed using Wilcoxon's rank-sum test or t test, as appropriate. Gender, mortality, and mechanism of injury were analyzed using chi analysis. RESULTS: A total of 143 patients were included. Patients who died during their hospitalization were excluded except in the analysis of ventilator-free days at day 28. After exclusions, 61 patients were in the control group and 58 in the protocol group. The median duration of mechanical ventilation in the protocol group was 1.2 days (0.5-3.0) which was significantly reduced compared with 3.2 days (1.0-12.9) in the control group (p = 0.027). Analysis of ventilator-free days at day 28 found that the protocol group had 26.4 ventilator-free days (13.9-27.4) compared with 22.8 days (10.5-26.9) in the control group (p = 0.007). The median ICU length of stay was 5.9 days (2.3-18.2) in the control group and 4.1 days (2.5-8.3) in the protocol group (p = 0.21). Hospital length of stay was 12 days (7-17) in the protocol group in contrast to 18 days (10-27) in the control group (p = 0.036). Opiate equivalents and propofol use per patient was significantly reduced in the protocol group from 2,465 mg (+/-1,242 mg) to 1,641 mg (+/-1,250 mg) and 19,232 mg (+/-22,477 mg) to 10,057 (+/-14,616 mg), respectively (p < 0.001, p = 0.01). CONCLUSION: An objective assessment- based ADS protocol without daily interruption of medication infusion decreases ventilator days and hospital length of stay in critically ill trauma patients.

Equine-related injury: a retrospective analysis of outcomes over a 10-year period.

BACKGROUND: Morbidity and financial loss caused by equine-related injuries may be significant. The purposes of this study were to determine the patterns of equine-related injury and the impact on outcomes. METHODS: A 10-year retrospective review of equine-related injuries was performed. Age, gender, mechanism, injury severity score, Glasgow Coma Score, length of stay, surgical interventions, and mortality were assessed. RESULTS: Of 80 emergency department evaluations, 76 patients were admitted and form the basis of this study. The most frequent mechanism of injury was fall (68%), followed by crush injuries (15%), kicks (8%), and trampling (5%). Musculoskeletal injuries were most common (64%). Thirty-eight (50%) patients required surgical intervention. Thirty-seven (52%) patients were discharged home; 34% required outpatient physical therapy, and 14% required inpatient rehabilitation. The mortality rate was 7%. CONCLUSIONS: Equine-related injuries resulted in significant morbidity; most victims required outpatient or inpatient rehabilitation. The use of preventive strategies may minimize mortality and reduce the financial impact of postinjury morbidity.

Assessment of the pregnant trauma patient.

Although less than 10% of pregnant patients are likely to experience some type of physical trauma, injury is the leading non-obstetric cause of maternal mortality. The assessment and resuscitation of the injured pregnant patient must take into account the specific needs of both the mother and the foetus. This paper will review the physiology of pregnancy, discuss recent changes in assessment and resuscitation, and identify special injuries and issues specific to the pregnant trauma patient.

Supplemental enteral arginine is metabolized to ornithine in injured patients.

BACKGROUND: Arginine has been added to immune enhancing diets that may improve patient outcomes, but little is known about the metabolic fate of supplemental arginine. We hypothesize that supplemental enteral arginine in injured patients is metabolized to ornithine by increased activity of the enzyme arginase. MATERIALS AND METHODS: Twenty-five adult patients with injury severity scores > or =20 received up to 14 days of enteral nutrition supplemented with arginine (30 g/day) or placebo in a prospective, randomized, blinded study. Plasma arginine, citrulline, and ornithine concentrations and peripheral blood mononuclear cell (PBMC) arginase activity were measured at baseline and on days 1, 3, 5, 7, 10, and 14. Clinical data collected included demographics, injury patterns, lengths of stay, and infectious complications. Data were analyzed using ANOVA and t test. RESULTS: PBMC arginase activity was elevated in all patients. In the supplemented group, plasma arginine concentrations increased at days 7, 10, and 14 when compared to baseline (P < 0.05) and were higher at day 14 when compared to those of controls (P < 0.05). Citrulline concentrations in both groups were unchanged over time. Ornithine concentration increased within 24 h of arginine supplementation and remained elevated when compared to baseline (P < 0.01). Ornithine concentration in the supplemented group was higher at days 1, 3, 5, and 7 when compared to that of controls (P < 0.05). There were no differences in clinical outcomes. CONCLUSIONS: Supplemental enteral arginine is absorbed in injured patients and increases arginine levels. Supplemental arginine appears to be metabolized to ornithine. Increased arginase enzyme activity in peripheral blood mononuclear cells may be a contributor.

The open peritoneal cavity: etiology correlates with the likelihood of fascial closure.

The use of laparostomy in damage control surgery and uncontrolled intra-abdominal infection has been well described. We examined 71 patients who required laparostomy to see if trends in management and outcome could be identified based on the underlying disease state. The underlying etiology included gastrointestinal sepsis (n = 25), pancreatitis (n = 21), or trauma (n = 25). Pancreatitis patients required more operations per patient (P < 0.05). The likelihood and type of closure (fascial, mesh, or none) was related to the underlying etiology: trauma patients were more likely to have fascial closure (P < 0.02), patients with GI sepsis were more likely to require mesh closure, and pancreatitis patients were more likely to have no formal closure (P < 0.02). Only 29 per cent of patients achieved definitive fascial closure. Mortality in trauma patients was 20 per cent, 36 per cent for GI sepsis, and 43 per cent in patients with pancreatitis. Complications of laparostomy included enterocutaneous fistula (16.9%) and abscess formation (7%). Though the use of laparostomy has become more prevalent, it is still associated with significant hospital stay, morbidity, and mortality. In our study, the number of operations and likelihood of abdominal closure appears to correlate with the etiology of the underlying disease requiring use of laparostomy.

Regulation of arginase expression by T-helper II cytokines and isoproterenol.

BACKGROUND: Trauma causes a release of catecholamines, transforming growth factor-beta (TGF-beta), and T-helper II cytokines (TH2). Individually, these substances also induce arginase in macrophages. The purpose of this study was to determine the synergistic interactions between isoproterenol, TGF-beta, and TH2 cytokines on arginase expression in macrophages. METHODS: Confluent RAW 264.7 macrophages were incubated with various combinations of interleukins 4, 10, and 13 (IL-4, IL-10, IL-13), and TGF-beta with isoproterenol over 48 hours. Arginase activity, as well as arginase I expression by Western blot and reverse transcriptase-polymerase chain reaction, were measured. RESULTS: Although isoproterenol, IL-4, IL-10, and IL-13 individually induced arginase, significant synergy between the combination of isoproterenol with either TGF-beta or the TH2 cytokines was observed. All cytokines except IL-10 also induced arginase I protein and mRNA. Arginase II protein was detected in cells exposed to IL-10. CONCLUSIONS: We conclude that isoproterenol synergizes with IL-4, IL-13, and TGF-beta to increase arginase I mRNA and protein, as well as arginase activity in RAW 264.7 macrophages. Further, IL-10 synergizes with isoproterenol to increase arginase activity and arginase II protein. These synergistic mechanisms may compete with nitric oxide synthase for l-arginine substrate, thus shunting away available arginine from nitric oxide production and contributing to cellular immunosuppression observed after trauma.

Hypothermia in the trauma patient.

Hypothermia is a common finding in severely injured patients. Historically described as a consequence of wartime casualties where cold exposure was common, this topic has resurfaced in the trauma literature because of the increasing recognition of the morbidity and mortality associated with hypothermia. Hypothermia, along with acidosis and coagulopathy, has been identified as a component of the "lethal triad" in injured patients, and has been shown to contribute to increased mortality in these patients. Decreases in core temperature during the course of initial evaluation and resuscitation are common, and can contribute to poor outcomes in the injured patient. As induced hypothermia has been shown to be beneficial in some clinical situations, recent animal studies have attempted to investigate whether hypothermia in the trauma patient has any beneficial effects. This review examines the incidence and pathophysiology of hypothermia, and discusses mechanisms of heat loss and rewarming techniques that can be utilized in the trauma patient.

Defining and assessing tolerance in enteral nutrition.

Nutrition support has become widely recognized as an essential component of optimal care for acutely ill patients. Enteral nutrition is preferred over parenteral routes when possible. However, prescribed enteral nutritional regimens are sometimes met with side effects and even complications. These adverse events have been collectively termed "intolerance," and forms of intolerance occur in a spectrum from bothersome at least to life threatening when most severe. Here we discuss nutritional access and its maintenance, introduce and define intolerance, and then review the current literature with regard to principal forms of enteral nutrition intolerance.