American Association for the Surgery of Trauma/American College of Surgeons-Committee on Trauma Clinical Protocol for inpatient venous thromboembolism prophylaxis after trauma.

ABSTRACT: Trauma patients are at increased risk of venous thromboembolism (VTE), which includes both deep vein thrombosis and pulmonary embolism. Pharmacologic VTE prophylaxis is a critical component of optimal trauma care that significantly decreases VTE risk. Optimal VTE prophylaxis protocols must manage the risk of VTE with the competing risk of hemorrhage in patients following significant trauma. Currently, there is variability in VTE prophylaxis protocols across trauma centers. In an attempt to optimize VTE prophylaxis for the injured patient, stakeholders from the American Association for the Surgery of Trauma and the American College of Surgeons-Committee on Trauma collaborated to develop a group of consensus recommendations as a resource for trauma centers. The primary goal of these recommendations is to help standardize VTE prophylaxis strategies for adult trauma patients (age ≥15 years) across all trauma centers. This clinical protocol has been developed to (1) provide standardized medication dosing for VTE prophylaxis in the injured patient; and (2) promote evidence-based, prompt VTE prophylaxis in common, high-risk traumatic injuries. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level V.

Airway pressure release ventilation reduces conducting airway micro-strain in lung injury.

BACKGROUND: Improper mechanical ventilation can exacerbate acute lung damage, causing a secondary ventilator-induced lung injury (VILI). We hypothesized that VILI can be reduced by modifying specific components of the ventilation waveform (mechanical breath), and we studied the impact of airway pressure release ventilation (APRV) and controlled mandatory ventilation (CMV) on the lung micro-anatomy (alveoli and conducting airways). The distribution of gas during inspiration and expiration and the strain generated during mechanical ventilation in the micro-anatomy (micro-strain) were calculated. STUDY DESIGN: Rats were anesthetized, surgically prepared, and randomized into 1 uninjured control group (n = 2) and 4 groups with lung injury: APRV 75% (n = 2), time at expiration (TLow) set to terminate appropriately at 75% of peak expiratory flow rate (PEFR); APRV 10% (n = 2), TLow set to terminate inappropriately at 10% of PEFR; CMV with PEEP 5 cm H2O (PEEP 5; n = 2); or PEEP 16 cm H2O (PEEP 16; n = 2). Lung injury was induced in the experimental groups by Tween lavage and ventilated with their respective settings. Lungs were fixed at peak inspiration and end expiration for standard histology. Conducting airway and alveolar air space areas were quantified and conducting airway micro-strain was calculated. RESULTS: All lung injury groups redistributed inspired gas away from alveoli into the conducting airways. The APRV 75% minimized gas redistribution and micro-strain in the conducting airways and provided the alveolar air space occupancy most similar to control at both inspiration and expiration. CONCLUSIONS: In an injured lung, APRV 75% maintained micro-anatomic gas distribution similar to that of the normal lung. The lung protection demonstrated in previous studies using APRV 75% may be due to a more homogeneous distribution of gas at the micro-anatomic level as well as a reduction in conducting airway micro-strain.

The relationship between annual hospital volume of trauma patients and in-hospital mortality in New York State.

BACKGROUND: Several studies in the literature have examined the volume-outcome relationship for trauma, but the findings have been mixed, and the associated impact of the trauma center level has not been examined to date. The purposes of this study are to (1) determine whether there is a significant relationship between the annual volume of trauma inpatients treated in a trauma center (with "patients" defined in multiple ways) and short-term mortality of those patients, and (2) examine the impact on the volume-mortality relationship of being a Level I versus Level II trauma center. METHODS: Data from New York's Trauma Registry in 2003 to 2006 were used to examine the impact of total trauma patient volume and volume of patients with Injury Severity Score (ISS) of at least 16 on in-hospital mortality rates after adjusting for numerous risk factors that have been demonstrated to be associated with mortality. RESULTS: The adjusted odds of in-hospital mortality patients in centers with a mean annual volume of less than 2,000 patients was significantly higher (adjusted odds ratio = 1.46, 95% confidence interval, 1.25-1.71) than the odds for patients in higher volume centers. The adjusted odds of mortality for patients in centers with an American College of Surgeons-recommended annual volume of less than 240 patients with an ISS of at least 16 was 1.41 times as high (95% confidence interval, 1.17-1.69) as the odds for patients in higher volume centers. However, for both volume cohorts analyzed, the variation in risk-adjusted in-hospital mortality rate was greater among centers within each volume subset than between these volume subsets. CONCLUSION: When considering the trauma system as a whole, higher total annual trauma center volume (2,000 or higher) and higher volume of patients with ISS ≥16 (240 and higher) are significant predictors of lower in-hospital mortality. Although the American College of Surgeons-recommended 1,200 total volume is not a significant predictor, hospitals in New York with ISS ≥16 volumes in excess of 240 also have total volumes in excess of 2,000. However, when considering individual trauma centers, high volume centers do not consistently perform better than low volume centers. Thus, despite the association between volume and mortality, we believe that the most accurate way to assess trauma center performance is through the use of an accurate, complete, comprehensive database for computing center-specific risk-adjusted mortality rates, rather than volume per se.

Severity of injury is underestimated in the absence of autopsy verification.

BACKGROUND: Trauma disproportionately affects young, productive citizens. To decrease the preventable death rate and morbidity, and to save society some of the estimated 230 million dollars per day revenue loss attributable to these injuries, trauma systems were developed. New York State instituted a population-based regional trauma registry to enter all patients meeting appropriate International Classification of Diseases, Ninth Revision diagnostic codes. METHODS: We evaluated the registry records deaths in a single New York State trauma region. We compared the medical records used for registry entry to the autopsy records from the County Medical Examiner's Office to determine accuracy of diagnostic coding. On the basis of autopsy data, the records were then recoded and the extent of the trauma rescored. RESULTS: One hundred thirty-four deaths from 1993 to 1998 were recorded. Twelve records (9%) were accurately entered. One hundred twenty-two records had 452 errors. The mean Injury Severity Score (ISS), based on the medical record face sheet, was 29.93. The revised ISS, based on autopsy review, was 34.44 (p = 0.0108, two-tailed t test). The 95% confidence interval of the difference was 1.05 to 7.96. Z scores were -14.36 before autopsy review and -13.21 after autopsy review (p = 0.4395, not significant). We demonstrated a significantly higher ISS in the patients who died when the autopsy findings were included for coding. This information was not available from the medical record. CONCLUSION: To accurately compare trauma center performance and injury severity, the inclusion of autopsy data is critically important. Present state law does not permit sharing of this information with the trauma centers. When comparing mortality rates of New York State trauma centers, data must be carefully interpreted.