External validation in an intermediate unit of a respiratory decompensation model trained in an intensive care unit.

BACKGROUND: Preventing urgent intubation and upgrade in level of care in patients with subclinical deterioration could be of great utility in hospitalized patients. Early detection should result in decreased mortality, duration of stay, and/or resource use. The goal of this study was to externally validate a previously developed, vital sign-based, intensive care unit, respiratory instability model on a separate population, intermediate care patients. METHODS: From May 2014 to May 2016, the model calculated relative risk of adverse events every 15 minutes (n = 373,271 observations) for 2,050 patients in a surgical intermediate care unit. RESULTS: We identified 167 upgrades and 57 intubations. The performance of the model for predicting upgrades within 12 hours was highly significant with an area under the curve of 0.693 (95% confidence interval, 0.658-0.724). The model was well calibrated with relative risks in the highest and lowest deciles of 2.99 and 0.45, respectively (a 6.6-fold increase). The model was effective at predicting intubation, with a demonstrated area under the curve within 12 hours of the event of 0.748 (95% confidence interval, 0.685-0.800). The highest and lowest deciles of observed relative risk were 3.91 and 0.39, respectively (a 10.1-fold increase). Univariate analysis of vital signs showed that transfer upgrades were associated, in order of importance, with rising respiration rate, rising heart rate, and falling pulse-oxygen saturation level. CONCLUSION: The respiratory instability model developed previously is valid in intermediate care patients to predict both urgent intubations and requirements for upgrade in level of care to an intensive care unit.

The effect of dead-on-arrival and emergency department death classification on risk-adjusted performance in the American College of Surgeons Trauma Quality Improvement Program.

BACKGROUND: The American College of Surgeons' Trauma Quality Improvement Program is focused on identifying variations in outcomes across trauma centers for the purposes of performance improvement. In previous analyses, patients who died in the emergency department were excluded. We investigated the effect of inclusion and exclusion of emergency department (ED) deaths (dead on arrival [DOA] and died in ED [DIE]) on analyses of overall risk-adjusted trauma center performance. METHODS: Data for patients admitted to 65 Trauma Quality Improvement Program hospitals during the 2009 calendar year was used. A logistic regression model was developed to estimate risk-adjusted mortality. Trauma centers were then ranked based on their observed-to-expected (O/E) mortality ratio with 90% confidence intervals (CIs) and classified by outlier status: low outliers/high performers had a 90% CI for O/E mortality ratio of less than 1, and high outliers/low performers had a 90% CI for O/E mortality ratio of greater than 1. Changes in outlier status, rank, and quartile were examined with and without DOA and DIE patients included in the analyses to discern the impact of such exclusions on overall risk-adjusted center-specific performance. RESULTS: Thirty-one trauma centers (48%) reported no DOA patients in 2009, while 6 centers (9%) reported more than 10. Of 224 patients, 14 (6.2%) had a documented time of death of more than 30 minutes after ED arrival despite being recorded as DOA. Forty-one trauma centers (63%) changed rank by three positions or less. Ten trauma centers changed their quartile ranking by a single quartile, but no centers were found to change quartile rank more than one quartile. Changes in outlier status occurred for 6 trauma centers (9%). CONCLUSION: The relative frequency of patients classified as DOA varies greatly between trauma centers. Misclassification of patients as DOA occurs. Inclusion of ED deaths in risk-adjusted analysis of mortality results in a small but insignificant change in predicting the outcome results of a trauma center. This change is less than the rate of finding a center to be a high or low outlier by chance alone using the 90% CI. Inclusion of DOA and DIE patients in risk-adjusted analysis of mortality is appropriate and eliminates the bias introduced by exclusion of ED deaths owing to misuse of the DOA classification. LEVEL OF EVIDENCE: Prognostic/epidemiologic study, level III.

Severe traumatic head injury affects systemic cytokine expression.

BACKGROUND: The neuroimmunologic effect of traumatic head injury remains ill-defined. This study aimed to characterize systemic cytokine profiles among traumatically injured patients to assess the effect of traumatic head injury on the systemic inflammatory response. STUDY DESIGN: For 5 years, 1,022 patients were evaluated from a multi-institutional Trauma Immunomodulatory Database. Patients were stratified by presence of severe head injury (SHI; head Injury Severity Score ≥4, n = 335) vs nonsevere head injury (NHI; head Injury Severity Score ≤3, n = 687). Systemic cytokine expression was quantified by ELISA within 72 hours of admission. Patient factors, outcomes, and cytokine profiles were compared by univariate analyses. RESULTS: SHI patients were more severely injured with higher mortality, despite similar ICU infection and ventilator-associated pneumonia rates. Expression of early proinflammatory cytokines, interleukin-6 (p < 0.001) and tumor necrosis factor-α (p = 0.02), was higher among NHI patients, and expression of immunomodulatory cytokines, interferon-γ (p = 0.01) and interleukin-12 (p = 0.003), was higher in SHI patients. High tumor necrosis factor-α levels in NHI patients were associated with mortality (p = 0.01), increased mechanical ventilation (p = 0.02), and development of ventilator-associated pneumonia (p = 0.01). Alternatively, among SHI patients, high interleukin-2 levels were associated with survival, decreased mechanical ventilation, and absence of ventilator-associated pneumonia. CONCLUSIONS: The presence of severe traumatic head injury significantly alters systemic cytokine expression and exerts an immunomodulatory effect. Early recognition of these profiles can allow for targeted intervention to reduce patient morbidity and mortality.

What is the safety of nonemergent operative procedures performed at night? A study of 10,426 operations at an academic tertiary care hospital using the American College of Surgeons national surgical quality program improvement database.

BACKGROUND: Ever-increasing numbers of in-house acute care surgeons and competition for operating room time during normal daytime business hours have led to an increased frequency of nonemergent general and vascular surgery procedures occurring at night when there are fewer residents, consultants, nurses, and support staff available for assistance. This investigation tests the hypothesis that patients undergoing such procedures after hours are at increased risk for postoperative morbidity and mortality. METHODS: Clinical data for 10,426 operative procedures performed over a 5-year period at a single academic tertiary care hospital were obtained from the American College of Surgeons National Surgical Quality Improvement Program Database. The prevalence of preoperative comorbid conditions, postoperative length of stay, morbidity, and mortality was compared between two cohorts of patients: one who underwent nonemergent operative procedures at night and other who underwent similar procedures during the day. Subsequent statistical comparisons utilized chi tests for comparisons of categorical variables and F-tests for continuous variables. RESULTS: Patients undergoing procedures at night had a greater prevalence of serious preoperative comorbid conditions. Procedure complexity as measured by relative value unit did not differ between groups, but length of stay was longer after night procedures (7.8 days vs. 4.3 days, p < 0.0001). CONCLUSIONS: Patients undergoing nonemergent general and vascular surgery procedures at night in an academic medical center do not seem to be at increased risk for postoperative morbidity or mortality. Performing nonemergent procedures at night seems to be a safe solution for daytime overcrowding of operating rooms.

The use of "war games" to enhance high-risk clinical decision-making in students and residents.

BACKGROUND: Initial studies found that residents and students performed poorly in simple clinical scenarios. We hypothesized that repeated simulations in the "war games" format would improve performance. METHODS: Participants included medical students and residents on the trauma and surgical intensive care unit (SICU) services. Subjects were given a nursing report of an unstable patient and asked to verbalize management of the situation. Responses were transcribed and graded. RESULTS: Eighty subjects and 5 experts participated in 227 simulations. Naive medical students, postgraduate year (PGY)-1, and PGY-2+ subjects performed worse than experts (P <.05). After participation in >/=3 war games sessions, trainees' scores were similar to experts. Subjects with the least amount of clinical experience demonstrated the most improvement. DISCUSSION: We have designed an educational system that rapidly enhances the cognitive performance of students and residents. This may represent an important tool in assessing and enhancing the competencies of medical trainees in a safe environment.

Differences in early- and late-onset ventilator-associated pneumonia between surgical and trauma patients in a combined surgical or trauma intensive care unit.

INTRODUCTION: Ventilator-associated pneumonia (VAP) is a leading cause of morbidity in the perioperative period. Based on differences in causes, VAP has been divided into early (96 hours of admission) onset. We sought to compare differences in patient characteristics and outcome between early- and late-onset VAP in trauma and nontrauma surgical patients. METHODS: A retrospective analysis of prospectively collected data were performed for all surgical and trauma patients admitted to the surgical or trauma intensive care unit of an academic medical center from December 1996 to March 2005 who developed VAP. Patients with early- and late-onset VAP were compared with regard to patient characteristics, cause, and outcome using bivariate and multivariate analyses. RESULTS: Three hundred thirty VAPs were identified in 233 trauma (71%) and 97 nontrauma surgery patients (29%). There was no statistically significant difference in recurrence, mortality, or length of stay between early- and late-onset VAP in trauma patients. Mortality for late- onset VAPs in nontrauma patients was 44% versus 23% for early-onset VAPs (p = 0.09). On a per case basis, trauma patients had significantly better mortality (11% vs. 41%) and length of stay (33.1 +/- 1.4 vs. 55.8 +/- 4.1 days) than nontrauma surgical patients with VAP (p < 0.0001), although the rate of VAP-related death favored the nontrauma patients (1.8 deaths of 100 intensive care unit trauma admissions vs. 1.1 deaths of 100 intensive care unit nontrauma admissions, p = 0.05). CONCLUSIONS: Although there is a trend toward worse outcome in nontrauma patients with late-onset VAP, trauma patients with late- and early-onset VAP behave similarly. On a per case basis, trauma patients have significantly better outcomes than nontrauma surgical patients with VAP when cared for within the same surgical or trauma intensive care unit.

The use of "war games" to evaluate performance of students and residents in basic clinical scenarios: a disturbing analysis.

BACKGROUND: "Failure to Rescue" is a term applied to clinical issues that, if unrecognized or improperly treated, lead to adverse outcomes. We examined the cognitive components of rescue through the use of a "War Games" simulator format. Our hypothesis was that junior and senior medical students would be less able than interns and residents to detail the actions needed to assess, intervene, and stabilize patients. METHODS: Medical students and residents rotating on the trauma and surgical intensive care unit service participated. Twelve scenarios were created to focus on basic floor emergencies. Scores were assigned for clinical actions ordered. The scenarios were validated by two critical care attending physicians, and these scores were used as the expert group. Scores were assigned by two examiners, and the average of the grades in each area was used. The scores are a ratio of actual to possible correct responses in each section, and in the entire exercise. RESULTS: Subjects were divided into third-year medical students (MS3), fourth-year students (MS4), first-year residents (PGY1), residents beyond their first year (PGY2+), and experts. There were 20 subjects and 5 experts (n = 85) in each group for a total of 140 simulated cases examined. On initial evaluation, MS4 and PGY2+ performed significantly worse than expert, and MS3 and PGY1 performed similarly to experts. On secondary evaluation, all groups performed significantly worse than the expert group. In determining the diagnosis, only MS3 differed significantly from the experts. On follow-up, and in total score, all performed significantly worse than the experts. DISCUSSION: All groups had significant deficits in cognitive performance compared with experts in the areas of secondary evaluation, follow-up of the presenting problem, and total performance in simple clinical scenarios. We must design educational systems that rapidly enhance the cognitive performance of students and residents before they are left to independently diagnose and intervene in life-threatening clinical situations.

How residents think and make medical decisions: implications for education and patient safety.

Medical errors are a major cause of morbidity and mortality, and cognitive errors account for many of these events. This study examined the basic science of the cognitive performance of trainees. We created a low-intensity medical simulator to perform a preliminary study of the ability of residents to recall and process patient information presented verbally. The subjects were separated into three categories based on critical care experience: novice (< or =8 weeks of critical care experience), intermediate (8-16 weeks of critical care experience), and expert (>16 weeks of critical care experience). The subjects were presented with three clinical cases. In the first case, the presentation contained 55 separate data points and subject recall was analyzed. In the second and third cases, a patient report was given, and the subjects were asked by a "medical student" to outline and explain their treatment decisions. Fifteen subjects completed the experiment (five novices, six intermediates, and four experts). Case 1 (recall): No significant differences among groups with regard to errors or total data points recalled (however, subjects who chose not to take notes had significantly poorer recall and committed more errors). Cases 2 and 3 (cognition and decision making): Intermediates and experts made significantly fewer errors. More importantly, the reasoning process (forward hypothesis based) of the more experienced residents differed from novices. This preliminary study demonstrates that the cognitive processes used by residents experienced in critical care are quantitatively and qualitatively different from those used by novices. These processes were also associated with far fewer cognitive errors in clinical decision making.

Proactive versus reactive: the effect of experience on performance in a critical care simulator.

BACKGROUND: We sought to study the cognitive performance of residents in a critical care patient simulator. METHODS: Residents in general surgery and emergency medicine were recruited to participate in the study. Subjects were read a morning report and presented with written data for 4 critical care patients. The subjects were evaluated on completing essential clinical tasks, cognitive errors, and directionality of reasoning. RESULTS: Nine residents completed the study. Months of clinical residency training did not significantly affect performance. Residents with more than 10 weeks of intensive care unit (ICU) experience (EXP) made significantly fewer cognitive errors than those with less than 10 weeks of ICU experience (N-I) (EXP: .75 +/- .96 vs N-I: 7 +/- 5.6 errors per subject, P < .05). An unexpected finding was that EXP performed far more proactive actions than N-I (EXP: 21.8 +/- 9.9/subject vs N-I: 5.7 +/- .6/subjects, P < .01). CONCLUSIONS: A unique finding was that residents with more than 10 weeks of ICU experience initiated a large number of proactive actions immediately following presentation of patient information, while N-I rarely performed these actions. In addition, residents with this degree of experience committed significantly fewer cognitive errors. These differences might play a role in efficiency, cost, and overall outcome in the care of ICU patients.

Does enteral glutamine supplementation decrease infectious morbidity?

BACKGROUND: Although some studies have demonstrated lower infectious morbidity in patients receiving supplemental glutamine, there remains no consensus on the utility of such treatment. This study was designed to investigate the effects of supplemental enteral glutamine on the rate and outcomes of infection in critically ill surgical patients. METHODS: All 185 surgical and trauma patients admitted to a single university surgical trauma intensive care unit (STICU) over an approximately three-year period who were to receive enteral nutrition support were assigned sequentially to one of three diets: standard 1-kCal/mL feedings with added protein (Group 1), standard feedings with glutamine 0.6 g/kg per day (Group 2), or immune-modulated feedings with a similar amount of glutamine (Group 3). Group compositions and patient characteristics were similar at baseline. Data were collected prospectively on infections acquired during hospitalization. RESULTS: A total of 119 patients had at least one infection: 59% of the patients in Group 1, 64% of Group 2, and 69% of Group 3 (p = NS). There were no differences among the groups in the mean number of infections. The most common sites in all groups were the lungs, blood, and urine; and the frequencies of these infections did not differ between groups. Minor differences were found between groups in the organisms isolated. Antibiotic usage did not differ. CONCLUSION: Supplemental enteral glutamine in the dose studied does not appear to influence the acquisition or characteristics of infection in patients admitted to a mixed STICU.

The "open-book" variation of component separation for repair of massive midline abdominal wall hernia.

The reconstruction of massive midline abdominal wall defects as a result of intra-abdominal catastrophes has long challenged the reconstructive surgeon. Previously, the lack of autogenous tissue often forced the surgeon to resort to synthetic materials, which may be complicated by adhesions, enterocutaneous fistulas, and infection. The introduction of the "components of anatomic separation" technique by Ramirez et al. in 1990 allowed for autogenous reconstruction using bipedicle rectus flaps. This technique was far superior to any previous option, but it had its limitations. The authors report a modification to the component separation technique which may allow larger defects to be closed as well as diminish the weakness left below the arcuate line found in some of the previously reported techniques. Ten patients are discussed for which this modified technique of component separation was employed. The follow-up ranges from 5 weeks to 53 months.

Differential local and systemic tumor necrosis factor-alpha responses to a second hit of lipopolysaccharide after hemorrhagic shock.

BACKGROUND: The immune response to subsequent stressors after traumatic hemorrhage and resuscitation (HR) may be dependent on timing and counterinflammatory cytokine expression. Our hypothesis was that the timing of the second hit would influence the immune response, and we investigated whether an early second stimulus after HR would result in worse acute lung injury. METHODS: One hour after HR or sham shock (Sham), mice were given intraperitoneal (IP) injections of lipopolysaccharide (LPS) or saline (Sal). Mortality, pulmonary function (PF), bronchoalveolar lavage neutrophil infiltration, and bronchoalveolar lavage (BAL), in addition to serum interleukin (IL)-10, IL-6, and tumor necrosis factor-alpha (TNF-alpha), were assessed. RESULTS: HR blunted serum TNF-alpha expression to LPS (HR+LPS, 424.8 pg/mL; Sham+LPS, 2,248.8 pg/mL; p < 0.05), but primed for increased bronchoalveolar lavage TNF-alpha (HR+LPS, 259.5 pg/mL; Sham+LPS, 23.5 pg/mL; p < 0.05). Elevated serum TNF-alpha corresponded with greater bronchoalveolar lavage neutrophil infiltration (HR+LPS, 0.93%; Sham+LPS, 17.5%; p < 0.05). IL-10 expression was similar in HR and Sham. There were no significant differences in mortality or PF between HR+LPS and Sham+LPS. CONCLUSION: Priming and blunting of the LPS-induced TNF-alpha response occurred concomitantly in two-hit mice, corresponding to an altered pattern of pulmonary inflammation, but no change in PF.

Comparing resident measurements to attending surgeon self-perceptions of surgical educators.

OBJECTIVE: The purpose of this study was to evaluate the initiation and utility of evaluating attending surgeons as educators by resident trainees. Additionally, we were interested in comparing resident measurements to attending self-perceptions. METHODS: A written evaluation form, (utilizing five-point ordinal scale assignments) queried respondents regarding the performance of surgical attendings in the operating room, and other clinical settings. A similar form was distributed to the faculty members, which they used to evaluate themselves. Mean scores were determined, as were comparisons between self-perception and resident assessments. Differences in scores with p values less than 0.05 were considered statistically significant. RESULTS: Thirty-six residents evaluated 23 attendings. Mean assignments by residents of performance in the operating room, other clinical settings, and overall scores for all faculty members as a group were 4.22 +/- 0.04, 4.11 +/- 0.03, and 4.16 +/- 0.03, respectively, with a score of five, generally corresponding to a most favorable rating. When overall scores were analyzed, 10 attendings received scores that differed significantly from those received by their peers, with half of subjects above, and the other half being below the 95% confidence interval. Eighteen (78%) of attendings completed the self-evaluation forms, and of these, 11 (61%) had self-perceptions that differed significantly from overall scores as reported by the residents. CONCLUSIONS: Our evaluation process delineated significant differences among attending faculty members and identified individual strengths and weaknesses. Many educators' self-perceptions differed significantly from resident assessments, and attendings who did not evaluate themselves scored lower than their peers.

Improved resuscitation minimizes respiratory dysfunction and blunts interleukin-6 and nuclear factor-kappa B activation after traumatic hemorrhage.

OBJECTIVE: We hypothesized that modifying resuscitation would alter hemorrhagic shock-induced respiratory dysfunction and correlate with nuclear factor-kappa B and cytokine expression. DESIGN: Randomized, controlled, prospective study. SETTING: University hospital trauma research laboratory. SUBJECTS: Female, Swiss Webster mice, 8-12 wks old. INTERVENTIONS: Hemorrhagic shock was induced by removing 0.025 mL of blood/g of body weight via a carotid catheter. Animals were resuscitated 30 mins later. Mice were randomized into four groups: group I was cannulated but not bled (sham); group II received normal saline to three times their shed blood volume; group III received their shed blood; and group IV received shed blood + normal saline at two times shed blood volume. MEASUREMENTS AND MAIN RESULTS: We measured the following: serum lactates at the end of shock and after resuscitation, pulmonary function before any instrumentation and after 24 hrs, cytokine concentrations by enzyme-linked immunosorbent assay, and nuclear factor-kappa B activity by electrophoretic mobility shift assay. Groups that were hemorrhaged had significant hypotension and a significant increase in serum lactates over 30 mins. Resuscitation returned the blood pressure to baseline in all groups, and lactates improved in all groups except group II. Group II also demonstrated a significant decrease in pulmonary function characterized by increased airway resistance and decreases in minute volume, lung compliance, and alveolar function. Bronchoalveolar fluid and serum interleukin-6 and whole lung nuclear factor-kappa B activity also were elevated significantly in group II. CONCLUSIONS: Group II demonstrated the least improvement in serum lactate after resuscitation, the most significant acute lung injury, and the greatest interleukin-6 and nuclear factor-kappa B response. Group IV mice had the least acute lung injury, with no detectable interleukin-6 response. Improved resuscitation with crystalloid and shed blood minimized acute lung injury. The reduction in pulmonary dysfunction after improved resuscitation may be attributable to a blunting of the nuclear factor-kappa B and interleukin-6 responses to hemorrhage.

Adenosine A2A analogue improves neurologic outcome after spinal cord trauma in the rabbit.

BACKGROUND: ATL-146e, an adenosine A2A agonist, reduces paralysis after spinal cord ischemia-reperfusion. We hypothesized that systemic ATL-146e could improve neurologic outcome after blunt spinal cord trauma. METHODS: Twenty rabbits survived a thoracic spinal cord impact of 30 g-cm. One group received 0.06 microg/kg/min ATL-146e for the first 3 hours after impact (A2A group), whereas a second group received saline carrier (T/C group). Neurologic outcome was measured using the Tarlov scale (0-5). Histologic sections from the A2A and T/C groups were compared for neuronal viability. RESULTS: There was significant improvement in Tarlov scores of A2A animals compared with T/C animals at 12 hours (p = 0.007), with a trend toward improvement at 36 (p = 0.08) and 48 (p = 0.09) hours after injury. There was decreased neuronal attrition in A2A animals (p = 0.06). CONCLUSION: Systemic ATL-146e given after spinal cord trauma results in improved neurologic outcome. Adenosine A2A agonists may hold promise as a rapidly acting alternative to steroids in the early treatment of the spinal cord injured patient.