Prediction of outcomes in trauma: anatomic or physiologic parameters?

BACKGROUND: Prediction of outcomes after injury has traditionally incorporated measures of injury severity, but recent studies suggest that including physiologic and shock measures can improve accuracy of anatomic-based models. A recent single-institution study described a mortality predictive equation [f(x) = 3.48 - .22 (GCS) - .08 (BE) + .08 (Tx) + .05 (ISS) + .04 (Age)], where GSC is Glasgow Coma Score, BE is base excess, Tx is transfusion requirement, and ISS is Injury Severity Score, which had 63% sensitivity, 94% specificity, (receiver operating characteristic [ROC] 0.96), but did not provide comparative data for other models. We have previously documented that the Physiologic Trauma Score, including only physiologic variables (systemic inflammatory response syndrome, Glasgow Coma Score, age) also accurately predicts mortality in trauma. The objective of this study was to compare the predictive abilities of these statistical models in trauma outcomes. METHODS: Area under the ROC curve of sensitivity versus 1-specificity was used to assess predictive ability and measured discrimination of the models. RESULTS: The study cohort consisted of 15,534 trauma patients (80% blunt mechanism) admitted to a Level I trauma center over a 3-year period (mean age 37 +/- 18 years; mean Injury Severity Score 10 +/- 10; mortality 4%). Sensitivity of the new predictive model was 45%, specificity was 96%, ROC was 0.91, validating this new trauma outcomes model in our institution. This was comparable with area under the ROC for Revised Trauma Score (ROC 0.88), Trauma and Injury Severity Score (ROC 0.97), and Physiologic Trauma Score (ROC 0.95), but superior compared with admission Glasgow Coma Score (ROC 0.79), Injury Severity Score (ROC 0.79), and age (ROC 0.60). CONCLUSIONS: The predictive ability of this new model is superior to anatomic-based models such as Injury Severity Score, but comparable with other physiologic-based models such as Revised Trauma Score, Physiologic Trauma Score and Trauma, and Injury Severity Score.     

Predictors of post-traumatic stress disorder following major trauma

Background: Post‐traumatic stress disorder (PTSD) is a common sequel to physical trauma, but there is disagreement regarding the predictors of this condition. This study aims to examine the role of physical, psychosocial and compensation‐related factors in the development of PTSD following major trauma. Methods: Participants were consecutive adult patients presenting to one major trauma centre with major trauma (Injury Severity Score 16 or higher). Baseline characteristics and clinical data were obtained from the hospital trauma database. The presence of PTSD (as measured by the PTSD Checklist, civilian version) and additional data were obtained from a questionnaire mailed to patients between 1 and 6 years after the injury. Multiple linear regression was used to identify significant independent associations with PTSD. Results: Among 355 patients (61.0% response fraction), 129 (36.3%, 95% confidence interval 43.2–53.2%) were classed as having PTSD. Symptoms of PTSD were not significantly related to measures of injury severity, the time since the injury, education level, household income or employment status at the time of injury. PTSD was significantly associated with younger age (P < 0.0001), the presence of chronic illnesses (P < 0.0001), unemployment at the time of follow up (P < 0.0001), use of a lawyer (P < 0.0001), blaming others for the injury (P = 0.003) and having an unsettled compensation claim (P = 0.007). Conclusion: Post‐traumatic stress disorder after major trauma was not related to measures of injury severity, but was related to other factors, such as blaming others for the accident and the processes involved in claiming compensation.     

Blast injury in a civilian trauma setting is associated with a delay in diagnosis of traumatic brain injury

High-pressure waves (blast) account for the majority of combat injuries and are becoming increasingly common in terrorist attacks. To our knowledge, there are no data evaluating the epidemiology of blast injury in a domestic nonterrorist setting. Data were analyzed retrospectively on patients admitted with any type of blast injury over a 10-year period at a busy urban trauma center. Injuries were classified by etiology of explosion and anatomical location. Eighty-nine cases of blast injury were identified in 57,392 patients (0.2%) treated over the study period. The majority of patients were male (78%) with a mean age of 40 +/- 17 years. The mean Injury Severity Score was 13 +/- 11 with an admission Trauma and Injury Severity Score of 0.9 +/- 0.2 and Revised Trauma Score of 7.5 +/- 0.8. The mean intensive care unit and hospital length of stay was 2 +/- 7 days and 4.6 +/- 10 days, respectively, with an overall mortality rate of 4.5 per cent. Private dwelling explosion [n = 31 (35%)] was the most common etiology followed by industrial pressure blast [n = 20 (22%)], industrial gas explosion [n = 16 (18%)], military training-related explosion [n = 15 (17%)], home explosive device [n = 8 (9%)], and fireworks explosion [n = 1 (1%)]. Maxillofacial injuries were the most common injury (n = 78) followed by upper extremity orthopedic (n = 29), head injury (n = 32), abdominal (n = 30), lower extremity orthopedic (n = 29), and thoracic (n = 19). The majority of patients with head injury [28 of 32 (88%)] presented with a Glasgow Coma Scale score of 15. CT scans on admission were initially positive for brain injury in 14 of 28 patients (50%). Seven patients (25%) who did not have a CT scan on admission had a CT performed later in their hospital course as a result of mental status change and were positive for traumatic brain injury (TBI). Three patients (11%) had a negative admission CT with a subsequently positive CT for TBI over the next 48 hours. The remaining four patients (14%) were diagnosed with skull fractures. All patients (n = 4) with an admission Glasgow Coma Scale score of less than 8 died from diffuse axonal injury. Blast injury is a complicated disease process, which may evolve over time, particularly with TBI. The missed injury rate for TBI in patients with a Glasgow Coma Scale score of 15 was 36 per cent. More studies are needed in the area of blast injury to better understand this disease process.     

Effect of alcohol on Glasgow Coma Scale in head-injured patients

OBJECTIVE: Almost 50% of traumatic brain-injured (TBI) patients are alcohol intoxicated. The Glasgow Coma Scale (GCS) is frequently used to direct diagnostic and therapeutic decisions in these patients. It is commonly assumed that alcohol intoxication reduces GCS, thus limiting its utility in intoxicated patients. The purpose of this study was to test the hypothesis that the presence of blood alcohol has a clinically significant impact on GCS in TBI patients. METHODS: The National Trauma Data Bank of the American College of Surgeons was queried (1994-2003). Patients 18 to 45 years of age with blunt injury mechanism, whose GCS in the emergency department, survival status, anatomic severity of TBI (Head Abbreviated Injury Score [AIS]), and blood alcohol testing status were known, were included. GCS of patients who tested positive for alcohol (n = 55,732) was compared with GCS of patients who tested negative (n = 53,197), stratified by head AIS. RESULTS: Groups were similar in age (31 +/- 8 vs. 30 +/- 8 years), Injury Severity Score (ISS; 12 +/- 11 vs. 12 +/- 11), systolic blood pressure in the ED (131 +/- 25 vs. 134 +/- 25 mm Hg), TRISS (Trauma Injury Severity Score; probability of survival (94% +/- 16% vs. 95% +/- 15%), and actual survival (96% vs. 96%). When stratified by anatomic severity of TBI, the presence of alcohol did not lower GCS by more than 1 point in any head AIS group (GCS in alcohol-positive vs. alcohol-negative patients; AIS 1 = 13.9 +/- 2.8 vs. 14.3 +/- 2.3; AIS 2 = 13.4 +/- 3.2 vs. 14.1 +/- 2.4; AIS 3 = 11.1 +/- 4.7 vs. 11.6 +/- 4.6; AIS 4 = 9.8 +/- 4.9 vs. 10.4 +/- 4.9; AIS 5 = 5.5 +/- 3.8 vs. 5.9 +/- 4.1, AIS 6: 3.4 +/- 1.1 vs. 3.8 +/- 2.8). CONCLUSION: Alcohol use does not result in a clinically significant reduction in GCS in trauma patients. Attributing low GCS to alcohol intoxication in TBI patients may delay necessary diagnostic and therapeutic interventions.     

Toll of methamphetamine on the trauma system

HYPOTHESIS: Methamphetamine use affects length of hospital stay in the minimally injured patient. DESIGN: Case series. SETTING: The only tertiary trauma center serving Hawaii. PATIENTS: Trauma patients examined during a 12-month period with an Injury Severity Score of 1 to 5 and an age of 18 to 55 years undergoing urine toxicology screen for suspected suicide attempt or altered sensorium. MAIN OUTCOME MEASURES: Presence or absence of amphetamine or methamphetamine on urine toxicology screen, intention of injury, hospital admission rate, length of stay, and hospital charges. RESULTS: During the study period, 1650 trauma patients were examined, with 544 meeting study criteria. Urine toxicology screens were performed in 212 patients, with 57 positive and 155 negative for amphetamine or methamphetamine. There was no difference in sex (77% vs 73% male; P =.53), Injury Severity Score (3.2 for both groups), or total number of computed tomographic scans performed (mean +/- SEM, 3.0 +/- 0.3 vs 4.0 +/- 0.3; P =.07). Patients in the positive group were more likely to have intentional self-inflicted injury or intentional assaults than patients in the negative group (37% vs 22%; P =.04). The positive group was older than the negative group (33.6 +/- 1.3 vs 29.9 +/- 0.8 years; P =.02), had a significantly longer hospital stay (2.7 +/- 0.4 vs 1.7 +/- 0.1 days; P =.003), had significantly higher hospital charges (15 617 dollars +/- 1866 dollars vs 11 600 dollars +/- 648 dollars; P =.01), and was more likely admitted to the hospital (91% vs 70%; P =.001) despite the low Injury Severity Score. CONCLUSION: Methamphetamine use results in trauma center resource utilization out of proportion to injury severity.     

Predicting quality of life six months after traumatic injury

BACKGROUND: Many factors are known to impact quality of life (QoL) after injury, but predictors of diminished QoL and the time course of recovery remain incompletely understood. This study examines predictors and correlates of QoL measured by the Short Form-36 (SF-36) one and six months postinjury. METHODS: Adults with nonneurologic blunt injury were prospectively enrolled. Demographic, injury, and socioeconomic data were collected. Patients were assessed with functional and psychologic measures. In all, 196 patients had 1-month data and 123 had 6-month data available. Scores were compared at each time point and also to population norms using t-tests. Multiple regression techniques were used to identify associations between the physical and mental component scores (PCS & MCS) of the SF-36 and patient characteristics. RESULTS: PCS scores improved significantly (32.8 +/- 0.9 versus 41.3 +/- 1.0, p < 0.05) whereas MCS scores (47.5 +/- 1.1 versus 47.2 +/- 1.1, p = NS) did not. Both remained significantly below population norms. Functional Independence Measure (FIM) at one month was predictive of PCS at 6 months. Posttraumatic stress disorder (PTSD) was predictive of lower MCS, and depression was associated with poor MCS. Injury Severity Score was not associated with PCS or MCS. CONCLUSIONS: Overall physical and mental QoL measured by the SF-36 remains significantly below population norms 6 months after traumatic injury. It is possible to identify patients at risk for diminished QoL early during recovery by screening for functional status, PTSD, social support, and depression. Interventions to address these areas should be further studied with respect to their impact on long-term QoL.     

The impact of liver dysfunction on outcome in patients with multiple injuries

Multiple organ dysfunction syndrome (MODS) is the leading cause of late deaths after traumatic injury. The relative importance of dysfunction of individual organ systems in determining outcome from MODS has not been clearly defined. Some studies have suggested that hepatic dysfunction associated with MODS increases mortality, whereas others have suggested that it contributes little to outcome in trauma patients. To clarify the role of the hepatic dysfunction after traumatic injury we retrospectively reviewed all trauma patients with an Injury Severity Score > or = 14 admitted from January 1, 1994 through June 30, 1997 for the presence of hepatic dysfunction defined as a serum bilirubin > or = 2.0 mg/dL. Of the 1962 patients who met the entry criteria 154 developed hepatic dysfunction during their hospital stay. Patients with hepatic dysfunction were older (46 +/- 2 versus 41 +/- 1 years), were more severely injured (Injury Severity Score 31.5 +/- 0.9 versus 23.3 + 0.2), and had a lower prehospital blood pressure (102 +/- 3 versus 117 +/- 1 mm Hg) compared with patients who did not develop hepatic dysfunction. Patients with hepatic dysfunction were more likely to present with shock as reflected in a lower initial emergency room blood pressure (109 +/- 3 versus 128 +/- 1 mm Hg) and base deficit (-6.9 +/- 0.6 versus -3.5 +/- 0.1 mEq/L). Patients who developed hyperbilirubinemia had longer lengths of stay in the intensive care unit (15.8 +/- 1.2 versus 3.4 +/- 0.2 days) and the hospital (27.4 +/- 1.7 versus 11.1 +/- 0.2 days) and a higher in-hospital mortality (16.2% versus 2.5%). These data demonstrate that the development of hepatic dysfunction reflects the severity of injury and is associated with a significantly worse outcome after traumatic injury.     

Trauma in pregnancy. Predicting pregnancy outcome

A multicenter study involving three American College of Surgeons Level 1 trauma centers was undertaken to assess parameters that may predict fetal outcome. The records of 93 injured pregnant patients admitted from April 1, 1985, to March 31, 1990, were reviewed. There were three maternal deaths (3%) (mean Injury Severity Score, 43). Fourteen fetal/neonatal deaths (15%) occurred during the acute care admission period. Of these, eight were fetal deaths (two associated with maternal death), four were cases of elective abortions, and two were neonatal deaths. In general, the maternal physiologic and laboratory parameters assessed failed to accurately predict pregnancy outcome, while Injury Severity Score did differ significantly between patients whose pregnancies were viable (Injury Severity Score = 6.2) and those whose pregnancies were nonviable (Injury Severity Score = 21.6). Unique to this study were the findings that the Glasgow Coma Score also differed significantly in patients with viable (Glasgow Coma Score, 14.5) and nonviable (Glasgow Coma Score, 12.0) pregnancies, while fetal heart rate at admission to the emergency department did not. In this study, the incidence of fetal death was increased following direct uteroplacental fetal injury (100% of cases), maternal shock (67%), pelvic fracture (57%), severe head injury (56%), and hypoxia (33%). The adequacy of noninvasive maternal monitoring in assessing fetal well-being is challenged, and a discussion of diagnostic modalities for assessment for the injured gravida is set forth.     

Beta-blockers in isolated blunt head injury

BACKGROUND: The purpose of this study was to evaluate the effect of beta-blockers on patients sustaining acute traumatic brain injury. Our hypothesis was that beta-blocker exposure is associated with improved survival. STUDY DESIGN: The trauma registry and the surgical ICU databases of an academic Level I trauma center were used to identify all patients sustaining blunt head injury requiring ICU admission from July 1998 to December 2005. Patients sustaining major associated injuries (Abbreviated Injury Score > or = 4 in any body region other than the head) were excluded. Patient demographics, injury profile, Injury Severity Score, and beta-blocker exposure were abstracted. The primary outcomes measure evaluated was in-hospital mortality. RESULTS: During the 90-month study period, 1,156 patients with isolated head injury were admitted to the ICU. Of these, 203 (18%) received beta-blockers and 953 (82%) did not. Patients receiving beta-blockers were older (50 +/- 21 years versus 38 +/- 20 years, p < 0.001), had more frequent severe (Abbreviated Injury Score > or = 4) head injury (54% versus 43%, p < 0.01), Glasgow Coma Scale < or = 8 less often (37% versus 47%, p = 0.01), more skull fractures (20% versus 12%, p < 0.01), and underwent craniectomy more frequently (23% versus 4%, p < 0.001). Stepwise logistic regression identified beta-blocker use as an independent protective factor for mortality (adjusted odds ratio: 0.54; 95% CI, 0.33 to 0.91; p = 0.01). On subgroup analysis, elderly patients (55 years or older) with severe head injury (Abbreviated Injury Score > or = 4) had a mortality of 28% on beta-blockers as compared with 60% when they did not receive them (odds ratio: 0.3; 96% CI, 0.1 to 0.6; p = 0.001). CONCLUSIONS: Beta-blockade in patients with traumatic brain injury was independently associated with improved survival. Older patients with severe head injuries demonstrated the largest reduction in mortality with beta-blockade.     

Peritraumatic and persistent dissociation as predictors of PTSD symptoms in a female cohort

Recent research has investigated peritraumatic and persistent dissociation as a possible predictive factor for posttraumatic stress disorder (PTSD). The current study aimed to add to this literature by examining dissociative responses in female assault survivors (N = 92 at initial assessment; n = 62 at follow-up). Dissociative symptoms experienced at 3 time points were assessed: peritraumatic dissociation (PD), persistent dissociation-initial (M = 28.2 days posttrauma) and follow-up (M = 224.9 days posttrauma), as well as initial and follow-up PTSD symptoms. We hypothesized that PD and persistent dissociative symptoms would predict chronic PTSD symptoms at the follow-up assessment with initial PTSD symptoms and assault type in the model. Hierarchical regression resulted in a significant model predicting 39% of the variance in follow-up PTSD symptom scores (p < .001). Both peritraumatic and follow-up persistent dissociative symptoms significantly and uniquely added to the variance explained in follow-up PTSD symptom score contributing 4% (p = .05) and 8% (p = .008) of the variance, respectively. Results support the predictive value of peritraumatic and persistent dissociative symptoms, and the findings suggest that persistent dissociation may contribute to the development and continuation of PTSD symptoms. We discuss the implications for assessment and possible treatment of PTSD as well as future directions.     

Peritraumatic reactions and posttraumatic stress disorder in psychiatrically impaired youth

Although peritraumatic dissociation and other subjective peritraumatic reactions, such as emotional distress and arousal, have been shown to affect the relationship between a traumatic event and the development of posttraumatic stress disorder (PTSD) in adults, systematic studies with youth have not been done. In a mixed ethnic and racial sample of 90 psychiatrically impaired youth (ages 10-18, 56% boys), we investigated the contributions of peritraumatic dissociation, emotional distress, and arousal to current PTSD severity after accounting for the effects of gender, trauma history, trait dissociation, and psychopathology (attention-deficit/hyperactivity disorder and depression). Peritraumatic dissociation emerged as the only peritraumatic variable associated with current PTSD severity assessed both by questionnaire and interview methods (β = .30 and .47 p < .01). Peritraumatic dissociation can be rapidly assessed in clinical practice and warrants further testing in prospective studies as a potential mediator of the trauma-PTSD relationship in youth.     

Frequency of burn-trauma patients in an urban setting

BACKGROUND: Burn-trauma patient encounters constitute 5% of the emergency department population. HYPOTHESIS: A large urban hospital will treat twice as many (ie, 10%) burn-trauma patients. DESIGN: Retrospective 44-month study. SETTING: Metropolitan county hospital. PATIENTS: Population-based sample of burn-only (n = 1102), burn-trauma (n = 120), and assault burn-trauma (n = 43) patients. MAIN OUTCOME MEASURES: Frequency and demographics. RESULTS: Just under 10% (n = 120) of the burn population had burn-trauma injuries. The mean +/- SD Injury Severity Score was 12 +/- 12 in these burn-trauma patients: 4 +/- 2 in outpatients and 14 +/- 13 in inpatients. The burn-only and burn-trauma groups had similar age ranges, ethnic distribution, frequency of inhalation injury, substance abuse, malnutrition, sepsis, pneumonia, diabetes mellitus, percentage total burn surface area, number of procedures, grafted areas, and mortality. Forty-three burn-trauma patients (35.8%) sustained injuries due to assault, compared with 123 (11.2%) in the burn-only group (P<.001). Burn-trauma patients who were assaulted had a mean +/- SD Injury Severity Score of 11 +/- 10. There was a significantly increased male-female ratio among the assault burn-trauma patients (6:1) compared with the burn-trauma (3:1) and burn-only (2.3:1) groups (P<.04). Most of these injuries were caused by an unknown assailant, in connection with an automobile, a motorcycle, a bicycle, or pedestrians intentionally struck by moving vehicles, or by child abuse. The main mechanism of injury was contact in 57 burn-trauma patients (47.5%), compared with 127 (11.5%) in the burn-only group (P<.001). CONCLUSIONS: A large urban population will have an increased frequency (2-fold in our center) of burn-trauma injuries. Assault and child abuse are significant contributory factors to burn-trauma injuries in this population.     

Long term impact of damage control surgery: a preliminary prospective study

BACKGROUND: To evaluate the impact of damage control laparotomy on long term morbidity and survival. METHODS: Prospective data were collected on 56 consecutive trauma patients over a 20-month period (May 2000-January 2002). Patients were stratified by mechanism of injury, age, Injury Severity Score, and type of injury, temperature at admission, initial blood transfusion volume and pH. Initial outcome data included major complications, intensive care unit and hospital length of stay, and mortality. Readmission data including number of admissions, surgical procedures, and hospital length of stay were then analyzed over the subsequent follow-up years (2001-2003). RESULTS: The mean age of the study group was 31 +/- 11 years with a mean Injury Severity Score of 33 +/- 13. The majority of the patients were male (73%) with a relatively equal number of blunt (n = 30) and penetrating injuries (n = 26). Liver injuries (34 [61%]) were the most common solid organ injury followed by 22 bowel (39%), 19 spleen (34%), 11 major vessel (20%), and 7 pancreas (13%) injuries. The mean number of initial abdominal surgical procedures was 4.4 +/- 2.2 per patient. The overall mortality during the first admission was 27%. Time spent in the intensive care unit and hospital length of stay was 17 +/- 13 and 30 +/- 19 days, respectively. There were a total of 74 readmissions and 58 subsequent surgical procedures in the 41 patients who were readmitted. Thirty-one (76%) patients were re-admitted at least one time. Infection (n = 19) was the most common reason for readmission followed by ventral hernia repair (n = 17) and fistula management (n = 14). There was 0% mortality for patients who survived the preliminary hospitalization but required readmission. CONCLUSION: Although damage control laparotomy is associated with a significant complication and readmission rate, its long term survival and benefit is indisputable.     

Posttraumatic stress symptoms in children recovering from minor orthopaedic injury and treatment

BACKGROUND: This study was designed to determine the prevalence of high levels of posttraumatic stress disorder (PTSD) symptoms among pediatric orthopaedic trauma patients recovering from injury and to see whether injury or demographic variables are associated with the presence of the symptoms. METHODS: Four hundred pediatric orthopaedic trauma patients completed the Child PTSD Symptom Scale questionnaire. Demographic and injury variables were tested to see if any were associated with the presence of high levels of posttraumatic stress symptoms. RESULTS: The average age of respondents was 11 years. The average time since injury was 36 days. The mean Injury Severity Score and summed Extremity Abbreviated Injury Score were 4 and 2, respectively. A total of 130 (33%) met criteria for high levels of PTSD symptoms. None of the variables tested were associated with high levels of PTSD symptoms, except one. Patients admitted to the hospital after injury were significantly more likely to develop high levels of PTSD symptoms. CONCLUSIONS: High levels of posttraumatic stress disorder symptoms are common in the recovery period after pediatric orthopaedic trauma, even among patients with relatively minor injury. Children admitted to the hospital after injury are at higher risk for such symptoms.     

Avoidant coping as a mediator between peritraumatic dissociation and posttraumatic stress disorder symptoms

Peritraumatic dissociation consistently predicts posttraumatic stress disorder (PTSD). Avoidant coping may serve as a mechanism through which peritraumatic dissociation contributes to PTSD symptoms. Path analysis was used to examine whether avoidant coping assessed 6 weeks following a motor vehicle accident mediated the relationship between in-hospital peritraumatic dissociation and 6-month (n = 193) and 12-month (n = 167) chronic PTSD symptoms. Results revealed that, after controlling for age, gender, depression, and 6-week PTSD symptoms, avoidant coping remained a partial mediator between peritraumatic dissociation and chronic PTSD symptoms 6- and 12-months postaccident. Post-hoc multigroup analyses suggested that at 6-months posttrauma, the mediation was significant in women, but not in men. Gender-specific results were not significant at 12-months posttrauma. Interventions targeted at reducing avoidant coping in high dissociators may aid in reducing PTSD symptoms.     

Uncompensated metabolic acidosis: an underrecognized risk factor for subsequent intubation requirement

BACKGROUND: There are no published reports identifying an inadequate ventilatory response to metabolic acidosis as a predictor of impending respiratory failure. Metabolic acidosis should induce a respiratory alkalosis in which the partial pressure of carbon dioxide (Paco2) is (1.5 [HCO3-] + 8) +/- 2. This study examined the relation between inadequate ventilatory compensation and intubation among trauma patients. METHODS: A retrospective chart review was performed for trauma patients admitted between January 1999 and December 2000. Age, gender, Injury Severity Score and combined Trauma and Injury Severity Score, chest injury, history of cardiac or pulmonary disease, partial pressure of oxygen (Pao2), Paco2, Glasgow Coma Score, respiratory rate, systolic blood pressure, base deficit, and ability to compensate were analyzed with respect to intubation and need for ventilator support. RESULTS: Of 140 patients with metabolic acidosis, 45 ultimately were intubated. The mean Paco2 for the unintubated patients was 34 +/- 7 mm Hg, as compared with 41 +/- 11 mm Hg for the intubated patients (p < 0.001). Only injury severity and ability to compensate for metabolic acidosis were independent predictors of intubation. Patients with inadequate compensation were 4.2 times more likely to require intubation when control was used for the Injury Severity Score (95% confidence interval, 1.8-9.7; p < 0.001). CONCLUSIONS: Inability to mount an adequate hyperventilatory response to metabolic acidosis is associated with an increased likelihood of respiratory failure and a need for ventilatory support. Recognition of this relation should lead to closer monitoring of patients with this condition, and could help to avert unforeseen crisis intubations. This observation needs to be validated in a prospective study.     

Venous thromboembolism in trauma: a local manifestation of systemic hypercoagulability?

BACKGROUND: The purpose of this study was to evaluate the relative importance of systemic hypercoagulability, preexisting and acquired risk factors, and specific injury patterns in the development of venous thromboembolism (VTE) after injury. METHODS: Injured patients with an Injury Severity Score > or = 15 were followed with lower extremity venous duplex ultrasonography, prothrombin fragment 1 + 2, and quantitative D-dimer levels at 1 and 3 days and then weekly until discharge. RESULTS: Among 101 patients with a mean Injury Severity Score of 27.3 +/- 10.5 followed for 12.4 +/- 8.7 days, 28 (27.7%) developed a lower extremity thrombosis, 2 (1.9%) sustained a pulmonary embolism, and 1 (0.9%) had a symptomatic upper extremity thrombosis. Although admission fragment 1 + 2 and D-dimer levels were elevated in 81.4% and 100% of patients, respectively, mean levels were not significantly different in those with or without VTE. VTE was more common (p < 0.05) among those with obesity, age > 40 years, immobilization for > 3 days, spine fractures, and lower extremity fractures. However, only obesity (p = 0.004) and immobilization > 3 days (p = 0.05) were independent predictors of VTE in a multivariate analysis. CONCLUSION: Although elevated in seriously injured patients, neither markers of activated coagulation nor specific injury patterns are predictive of VTE. Associations with immobilization and obesity suggest that VTE after injury is a systemic hypercoagulable disorder with local manifestations of thrombosis related to lower extremity stasis.     

CXCR2 regulation of tumor necrosis factor-alpha adherence-dependent peroxide production is significantly diminished after severe injury in human neutrophils

BACKGROUND: Primed neutrophils are thought to play a key role in inflammatory pathology. We have shown though in vitro studies that interleukin (IL)-8 and growth-related oncogene-alpha (GROalpha) (CXCR2-specific chemokines) regulate the respiratory burst via the CXCR2 receptor. We have also shown in vivo, CXCR2 receptors are down-regulated in severely injured patients. Our hypothesis is that regulation of the respiratory burst by CXCR2 is lost after severe injury. METHODS: Patient neutrophils were studied within 24 hours of admission to the hospital; excluded were severe head injury and patients with Injury Severity Score < 16. Patient and normal neutrophils were isolated by Ficoll-Hypaque centrifugation after dextran sedimentation. Neutrophils were plated with buffer, 50 nmol/L IL-8 or GROalpha on fibronectin-coated plates for 15 minutes, then stimulated with 10 ng/mL of TNFalpha. CXCR2 expression was measured by flow cytometry. Receptor function was assessed by calcium mobilization. RESULTS: One female and 10 male patients with an average age of 37 +/- 3 and Injury Severity Score of 24 +/- 5 suffered blunt injury. CXCR2 showed a 32% +/- 7% loss, whereas CXCR1 showed 15% +/- 6% reduction. GROalpha stimulation of patient neutrophils showed 60% +/- 16% decrease in calcium mobilization, whereas IL-8 showed no decline. At 40 minutes, IL-8 and GROalpha significantly inhibited TNFalpha adherence-dependent peroxide production in normal neutrophils (35% +/- 4% and 45% +/- 3%, respectively; p < 0.05). Both IL-8 and GROalpha lost the ability to suppress the respiratory burst in severely injured patients, but GROalpha had a significantly greater loss of this suppression (p = 0.004). CONCLUSION: IL-8 and GROalpha lose the ability to regulate the TNFalpha-induced respiratory burst. This may contribute to neutrophil dysregulation after injury and result in organ injury.     

Pulmonary contusions: quantifying the lesions on chest X-ray films and the factors affecting prognosis.

OBJECTIVES: To quantify pulmonary contusions on chest x-ray film and to evaluate factors correlating with the size of the pulmonary contusions, changes in the first 24 hours, the need for ventilatory assistance, and death. METHODS: The medical records and chest x-ray films of 103 patients with blunt chest trauma diagnosed as having a pulmonary contusion were reviewed. RESULTS: A pulmonary contusion score was developed (3 = one third of a lung; 9 = an entire lung). In the emergency department, pulmonary contusions were not present in 11, were mild (one ninth to two ninths of a lung) in 15 patients, moderate-severe (three ninths to nine ninths of a lung) in 53 patients, and very severe in 24 patients. Within 24 hours, the pulmonary contusion score increased in 26 patients by 7.9 +/- 5.5 (SD). The 26 patients with an increasing contusion had a higher mortality rate (38% vs. 17%) (p = 0.044) and tended to need ventilatory assistance more frequently (73% vs. 49%) (p = 0.061). The 35 patients with very severe pulmonary contusions (pulmonary contusion score = 10-18) had the lowest PaO2:FIO2 ratio at 24 hours (175 +/- 103 mm Hg), longest hospital length of stay (28 +/- 35 days), and the highest Injury Severity Score (26 +/- 9). The factors correlating highest with a need for ventilatory support (57/103) were the 24 hour or initial PaO2/FIO2 ratio < 300, an Injury Severity Score > or = 24, Revised Trauma Score < 6.4, Glasgow Coma Scale score < or = 12, and shock or need for blood in the first 24 hours (p < 0.001). Death correlated highly with a need for ventilatory assistance, Injury Severity Score > or = 26, Revised Trauma Score < or = 6.3, and Glasgow Coma Scale score < or = 11 (p < 0.001). CONCLUSION: Quantifying and noting changes in the extent of the pulmonary contusions and PaO2/FIO2 ratio during the first 24 hours may be of value in determining the need for ventilatory assistance and predicting outcome.     

Increased rate of infection associated with transfusion of old blood after severe injury

HYPOTHESIS: Blood components undergo changes during storage that may affect the recipient, including the release of bioactive agents, with significant immune consequences. We hypothesized that transfusion of old blood increases infection risk in severely injured patients. DESIGN: Prospective cohort study. SETTING: Urban level I regional trauma center. PATIENTS: Sixty-one trauma patients with an Injury Severity Score greater than 15, age older than 15 years, and survival longer than 48 hours who were transfused with 6 to 20 U of red blood cells in the first 12 hours after injury were studied. By means of blood bank records, the age of each unit of blood was determined. INTERVENTION: Transfusion of allogeneic red blood cells. MAIN OUTCOME MEASUREMENTS: Major infectious complications. RESULTS: The early (<12 hours) transfusion requirement was 12 +/- 0.6 U, with a mean age 27 +/- 1 days. Major infections developed in 32 patients (52%). Age and Injury Severity Score were not significantly different between patients who developed infections and those who did not (age, 39 +/- 4 vs 36 +/- 3 years; Injury Severity Score, 33 +/- 1.5 vs 29 +/- 1.5). Transfusion of older blood was associated with subsequent infection; patients who developed infections received 11.7 +/- 1.0 and 9.9 +/- 1.0 U of red blood cells older than 14 and 21 days, respectively, compared with 8.7 +/- 0.8 and 6.7 +/- 0.08 in patients who did not develop infections (both P<.05, t test). Multivariate analysis confirmed age of blood as an independent risk factor for major infections. CONCLUSIONS: Transfusion of old blood is associated with increased infection after major injury. Other options, such as leukocyte-depleted blood or blood substitutes, may be more appropriate in the early resuscitation of trauma patients requiring transfusion.