The impact of clinical risk factors in the conversion from acute lung injury to acute respiratory distress syndrome in severe multiple trauma patients

Complications and Mortality Among Correctly Triaged and Undertriaged Severely Injured Older Adults With Traumatic Brain Injuries

Determining differences in clinical outcomes of older adults treated at trauma centers (TCs) and nontrauma centers (NTCs) is imperative considering their persistent undertriage and the projected costs of fixing the problem. This study compared the incidence and predictors of complications and mortality among brain-injured older adults treated at TCs and NTCs. This secondary analysis of New York inpatient data included patients aged 55+ years, primary brain injury diagnosis, and acute care hospital admission. Interfacility transfers and nontraumatic brain injuries were excluded. International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnosis codes identified complications and mortality. Injury severity was determined by mapping ICD-9-CM diagnoses to Abbreviated Injury Scale 2005 Revision 2008 dictionary scores. A subgroup analysis of 1,594 patients with New Injury Severity Scores greater than 15 was performed to examine complications and mortality. This study included 7,138 patients who met inclusion criteria. Predictors of subgroup complications included chronic renal failure, odds ratio (OR) = 2.251 (confidence interval [CI] = 1.470-3.447), p < .001; major operating room procedure, OR = 2.349 (CI = 1.679-3.285), p < .001; number of diagnoses, OR = 1.201 (CI = 1.158-1.245), p < .001; and number of procedures, OR = 1.119 (CI = 1.077-1.162), p £ .001. Mortality predictors included age, OR = 1.031 (CI = 1.017-1.045), p < .001; preexisting coagulopathy, OR = 1.753 (C = 1.130-2.719), p = .012; number of procedures, OR = 1.122 (CI = 1.081-1.166), p < .001; acute renal failure, OR = 3.114 (CI = 1.672-5.797), p < .001; systemic inflammatory response syndrome, OR = 4.058 (CI = 1.463-11.258), p = .007; adult respiratory distress syndrome, OR = 3.179 (CI = 1.673-6.041), p < .001; and subarachnoid bleed, OR = 2.667 (CI = 1.415-5.029), p = .002. Nearly 23% of the severely/critically injured patients experienced 1 or more complications. Incidence of complications was low and comparable for TCs and NTCs. The proportion of deaths was slightly higher at TCs but not significant. The most prevalent complications carry a high mortality risk.

Ten-year retrospective analysis of multiple trauma complicated by pulmonary contusion

BACKGROUND

This study reports a 10-year retrospective analysis of multiple trauma complicated by pulmonary contusion. The purpose of this study is to ascertain the risk factors for mortality due to trauma in patients with pulmonary contusion, the impact of various treatment options for prognosis, and the risk factors for concurrent Acute Respiratory Distress Syndrome (ARDS).

METHODS

We retrospectively analyzed 252 trauma patients with lung contusion admitted to the General Hospital of Guangzhou Command from January 2000 to June 2011 by using the statistical processing system SPSS 17.0 for Windows.

RESULTS

We included 252 patients in our study, including 214 males and 38 females. The average age was 37.1 ± 14.9 years. There were 110 cases admitted to the ICU, of which 26 cases with ARDS. Nine of the 252 patients died. We compared those who survived with those who died by gender and age, the difference was not statistically significant (P = 0.199, P = 0.200). Separate univariate analysis of those who died and those who survived found that shock on admission (P = 0.000), coagulation disorders (P = 0.000), gastrointestinal bleeding (P = 0.02), the need for emergency surgery on admission (P = 0.000), pre-hospital intubation (P = 0.000), blood transfusion within 24 hours (P = 0.006), the use of mechanical ventilation (P = 0.000), and concurrent ARDS (P = 0.000) are poor prognosis risk factors. Further logistic analysis, including the admission GCS score (OR = 0.708, 95% CI 0.516-0.971, P = 0.032), ISS score (OR 1.135, 95% CI 1.006-1.280, P = 0.039), and concurrent ARDS (OR = 15.814, 95% CI 1.819-137.480, P = 0.012), identified the GCS score, ISS score and concurrent ARDS as independent risk factors of poor prognosis. Shock (OR = 9.121, 95% CI 0.857-97.060, P = 0.067) was also related to poor prognosis. Patients with injury factors such as road accident, falling injury, blunt injury and crush injury, et al.(P = 0.039), infection (P = 0.005), shock (P = 0.004), coagulation disorders (P = 0.006), emergency surgery (P = 0.01), pre-hospital intubation (P = 0.000), chest tube insertion (P = 0.004), blood transfusion (P = 0.000), usage of hormones (P = 0.002), phlegm (P = 0.000), ventilation (P = 0.000) were at a significantly increased risk for ARDS complications.

CONCLUSIONS

Those patients with multiple trauma and pulmonary contusion admitted to the hospital with shock, coagulopathy, a need for emergency surgery, pre-hospital intubation, and a need for mechanical ventilation could have a significantly increased risk of mortality and ARDS incidence. A risk for poor prognosis was associated with gastrointestinal bleeding. A high ISS score, high APACHE2, and low GCS score were independent risk factors for poor prognosis. If patients developed an infection or were given drainage, hormones, and phlegm treatment, they were at higher risk of ARDS. Pre-hospital intubation and drainage were independent risk factors for ARDS. In patients with ARDS, the ICU stay, total length of stay, and hospital costs might increase significantly. A GCS score < 5.5, APACHE 2 score > 16.5, and ISS score > 20.5 could be considered indicators of poor prognosis for patients with multiple trauma and lung contusion.

Simvastatin attenuates the lipopolysaccharideinduced inflammatory response of rat pulmonary microvascular endothelial cells by downregulating toll-like receptor 4 expression

Objective

The therapeutic potential of simvastatin as an anti-inflammatory agent was explored by investigating its effect on the lipopolysaccharide (LPS)-induced inflammatory response in rat pulmonary microvascular endothelial cells (RPMVECs).

Methods

RPMVECs were isolated and the mRNA and protein levels of different toll-like receptors (TLR) were assessed by qRT-PCR and western blotting. The LPS-induced expressions of TLR4, TNF-α and iNOS were analyzed in RPMVECs treated with different concentrations of simvastatin for different times. NF-κB activation was examined by immuofluroscence, luciferase reporter assay and western blotting.

Results

TLR4 is abundantly expressed in RPMVECs, and its expression is induced by LPS stimulation. Simvastatin inhibited LPS-induced TLR4 expression at the mRNA and protein levels in a time-dependent manner (p<0.01), and alleviated inflammation in RPMVECs by inhibiting the release of inflammatory factors such as TNF-α and iNOS. Further study indicated that simvastatin significantly attenuated NF-κB activity by inhibiting the degradation of IκB-α. Pretreatment with pyrrolidine dithiocarbamate (PDTC) and knock-down of TLR4 expression by RNA interference down-regulated the LPS-induced inflammatory response in RPMVECs.

Conclusion

Simvastatin inhibits the LPS-induced inflammatory response in RPMVECs by down-regulating TLR4 expression, suggesting its role as a potential inhibitor of LPS-induced inflammation

An innovative approach to predict the development of adult respiratory distress syndrome in patients with blunt trauma

BACKGROUND

Pulmonary contusion (PC) is a common injury associated with blunt chest trauma. Complications such as pneumonia and adult respiratory distress syndrome (ARDS) occur in up to 50% of patients with PC. The ability to predict which PC patients are at increased risk of developing complications would be of tremendous clinical utility. In this study, we test the hypothesis that a novel method that objectively measures percent PC can be used to identify patients at risk to develop ARDS after injury.

METHODS

Patients with unilateral or bilateral PC with an admission chest computed tomographic angiogram were identified from the trauma registry. Demographic, infectious, and outcome data were collected. Percent PC was determined on admission chest computed tomography using our novel semiautomated, attenuation-defined computer-based algorithm, in which the lung was segmented with minimal manual editing. Factors contributing to the development of ARDS were identified by both univariate and multivariable logistic regression analyses. ARDS was defined as PaO2/FiO2 ratio of less than 200 with diffuse bilateral infiltrates on chest radiograph with no evidence of congestive heart failure.

RESULTS

Quantifying percent PC from our objective computer-based approach proved successful. We found that a contusion size of 24% of total lung volume or greater was most significant at predicting ARDS, which occurred in 78% of these patients. Such patients also had a significantly higher incidence of pneumonia when compared with those with contusions less than 24%. The specificity of contusion size of 24% or greater was 94%, although sensitivity was 37%; positive predictive value was 78%, and negative predictive value was 72%.

CONCLUSION

We developed and describe a software-based methodology to accurately measure the size of lung contusion in patients of blunt trauma. In our analyses, contusions of 24% or greater most significantly predict the development of ARDS. Such an objective approach can identify patients with PC who are at increased risk for developing respiratory complications before they happen. Further research is needed to use this novel methodology as a means to prevent posttraumatic lung injury in patients with blunt trauma.

LEVEL OF EVIDENCE

Prognostic/epidemiologic study, level III; diagnostic study, level IV.

Rotational bed therapy after blunt chest trauma: a nationwide online-survey on current concepts of care in Germany

INTRODUCTION

Blunt chest injuries are amongst the most life threatening injuries in adult multiple trauma patients. Nevertheless, the treatment of these thoracic injuries has not been standardized yet. Previous publications have reported on the prevention and the treatment of respiratory complications by using continuous lateral rotational bed therapy (CLRT), but there is still a lack of information using this approach in the presence of pulmonary contusions. Therefore current literature indicates a variety of treatment protocols and its use is contended.

METHODS

We submitted a 32-item online-questionnaire to 155 hospitals participating in the nationwide TraumaNetwork to assess current treatment concepts in multiple trauma patients suffering from blunt chest trauma including lung contusions with particular focus on the use of CLRT. Overall, 21 level I, 53 level II and 81 level III trauma centres were contacted. The questionnaire was created using "interview 123 5.5.b.de ND6".

RESULTS

The overall response rate was 35.5% (55/155) and responses were received from 10 level I (47.6%), 17 level II (32.1%) and 24 level III (29.6%) trauma centres. Thirty-five of the responders (63.6%) declared to be able to perform lateral rotational bed therapy. For level I and II trauma centres more than 80% were able to apply kinetic positioning in contrast to only 50% of level III trauma centres. Although 42.9% of the participants reported on the existence of standardized treatment protocols, 57.1% failed to report a standardized operating procedure for CLRT. The annual mean number of patients per centre treated via CLRT was 15 (0-130). Treatment modalities such as PEEP and the duration of CLRT also showed great variability. Against this background three out of four centres declared an urgent need for further clinical research in the field.

CONCLUSIONS

Our data reflect the wide range of different CLRT treatment strategies performed for blunt pulmonary trauma involving lung contusions in German trauma centres. We conclude that a high-quality randomized-controlled trial is warranted to critically assess the role of CLRT in multiple trauma patients with blunt chest trauma to provide a sound basis for future clinical guidelines.

Initial assessment of chest X-ray in thoracic trauma patients: Awareness of specific injuries

AIM: To compare the reported injuries on initial assessment of the chest X-ray (CXR) in thoracic trauma patients to a second read performed by a dedicated trauma radiologist.

METHODS: By retrospective analysis of a prospective database, 712 patients with an injury to the chest admitted to the University Medical Center Utrecht were studied. All patients with a CXR were included in the study. Every CXR was re-evaluated by a trauma radiologist, who was blinded for the initial results. The findings of the trauma radiologist regarding rib fractures, pneumothoraces, hemothoraces and lung contusions were compared with the initial reports from the trauma team, derived from the original patient files.

RESULTS: A total of 516 patients with both thorax trauma and an initial CXR were included in the study. After re-evaluation of the initial CXR significantly more lung contusions (53.3% vs 34.1%, P < 0.001), hemothoraces (17.8% vs 11.0%, P < 0.001) and pneumothoraces (34.4% vs 26.4%, P < 0.001) were detected. During initial assessment significantly more rib fractures were reported (69.8% vs 62.3%, P < 0.001).

CONCLUSION: During the initial assessment of a CXR from trauma patients in the emergency department, a significant number of treatment-dictating injuries are missed. More awareness for these specific injuries is needed.

Small interference RNA targeting TLR4 gene effectively attenuates pulmonary inflammation in a rat model

Objective. The present study was to investigate the feasibility of adenovirus-mediated small interference RNA (siRNA) targeting Toll-like receptor 4 (TLR4) gene in ameliorating lipopolysaccharide- (LPS-) induced acute lung injury (ALI). Methods. In vitro, alveolar macrophages (AMs) were treated with Ad-siTLR4 and Ad-EFGP, respectively, for 12 h, 24 h, and 48 h, and then with LPS (100 ng/mL) for 2 h, and the function and expression of TLR4 were evaluated. In vivo, rats received intratracheal injection of 300 μL of normal saline (control group), 300 μL of Ad-EGFP (Ad-EGFP group), or 300 μL of Ad-siTLR4 (Ad-siTLR4 group) and then were intravenously treated with LPS (50 mg/kg) to induce ALI. Results. Ad-siTLR4 treatment significantly reduced TLR4 expression and production of proinflammatory cytokines following LPS treatment both in vitro and in vivo. Significant alleviation of tissue edema, microvascular protein leakage, and neutrophil infiltration was observed in the AdsiTLR4-treated animals. Conclusion. TLR4 plays a critical role in LPS-induced ALI, and transfection of Ad-siTLR4 can effectively downregulate TLR4 expression in vitro and in vivo, accompanied by alleviation of LPS-induced lung injury. These findings suggest that TLR4 may serve as a potential target in the treatment of ALI and RNA interfering targeting TLR4 expression represents a therapeutic strategy.

Infectious complications after vehicular trauma in the United States

BACKGROUND

The purpose of this analysis was to evaluate and define the rates of infectious complications (IC) after vehicular trauma. Secondary goals were to identify the injuries associated with the greatest risk of nosocomial infection and to measure the utilization of hospital resources associated with IC and vehicular trauma.

METHODS

A secondary analysis of the Nationwide Inpatient Sample (2003-2007) was performed to classify major vehicular trauma injuries utilizing International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) Emergency (E) codes. The post-traumatic IC evaluated were pneumonia, urinary tract infection (UTI), sepsis, and surgical site infection (SSI). All data were analyzed by χ(2) analysis, multivariable logistic regression, and the Cochran-Armitage test for trends.

RESULTS

A total of 784,037 vehicular trauma patients were identified (462,543 [59.0%] motor vehicle drivers, 142,283 [18.2%] motor vehicle passengers, 98,767 [12.6%] motorcyclists; 6,568 [<1%] motorcycle passengers, and 73,876 [9.4%] pedestrians). Of those sustaining injuries, 44,331 [5.7%] had post-traumatic IC. Pneumonia and UTI were most common after spinal cord injury (SCI), whereas sepsis and SSI were most common after colon injuries. After adjustment by age, sex, and co-morbidities, patients with SCI were 4.4 times as likely (95% confidence interval [CI] 4.20-4.63) and those with cranial injuries were 2.1 times as likely (95% CI 2.06-2.19) to develop IC as patients without these injuries. Secondary infection increased significantly the length of stay and hospital charges in all groups.

CONCLUSIONS

Patients sustaining vehicular trauma in combination with SCI had the highest rate of IC. Infectious complications increased hospital resource utilization significantly after vehicular trauma. Future root-cause analysis of high-risk groups may decrease complications and hospital utilization.

Angiotensin-converting enzyme insertion/deletion polymorphism associated with acute respiratory distress syndrome among caucasians

Studies investigating the association between angiotensin-converting enzyme (ACE) insertion/deletion polymorphisms and the risk of acute respiratory distress syndrome (ARDS) report conflicting results. The objective of the present study was to summarize quantitatively the evidence for such a relationship. Two investigators independently searched the MEDLINE (January 1966 - October 2009) and EMBASE (January 1980 - October 2009) databases. This meta-analysis included six case-control studies, which included 514 ARDS cases and 2619 controls. The combined results based on all studies showed that patients with ARDS had a significantly higher frequency of the ACE deletion/deletion (DD) genotype (odds ratio [OR] 1.56; 95% confidence interval [CI] 1.22, 2.00) than controls. When stratifying for race, no significant differences in genotype distribution were found except that Caucasian patients with ARDS had a significantly higher frequency of the DD genotype (OR 1.65; 95% CI 1.27, 2.13) than controls. This meta-analysis suggests that ACE insertion/deletion polymorphisms may be associated with ARDS among Caucasians.

Selective medicated (saline + natural surfactant) bronchoalveolar lavage in unilateral lung contusion. A clinical randomized controlled trial

OBJECTIVE

Open lung and low tidal volume ventilation appear to be a promising ventilation for chest trauma as it can reduce ARDS and improve outcome. Local therapy (e.g. BAL) can be synergic to remove from the lung the debris, mitigate inflammatory cascade and avoid damage spreading to not compromised lung areas.

MATERIALS AND METHODS

44 pulmonary contused patients were randomized to receive broncho-suction and volume controlled low tidal volume ventilation-VCLTVV (Control Group) or the same ventilation plus medicated (saline + surfactant) BAL (Treatment Group). Tidal volume <10 ml/kg, PEEP of 10-12 cm H(2)O and PaO(2) 60-100 mm Hg and PaCO(2) 35-45 mm Hg were used in both groups. BAL was performed using a fiberscope. 4 boluses of 25 ml saline with 2.4 mg/ml of surfactant were introduced into each contused lobe in which, subsequently, 240 mg of surfactant was instilled.

RESULTS

All patients survived. In the Control Group 18 patients developed pneumonia, 5 ARDS and days of intubation were 11.50 (3.83) compared to 5.05 (1.21) of Treatment Group in which OI and PaO(2)/FiO(2) significantly improved from 36 h.

CONCLUSIONS

VCLTVV alone was not able to prevent ARDS and infection in the Control Group as the reduction of intubation. In the Treatment Group, VCLTVV and medicated BAL facilitated the removal of degradated lung material and recruited the contused lung regions, enabling the healing of the lung pathology.