Richard K. Simons

Lethal injuries and time to death in a level I trauma center

BACKGROUND The purpose of this study was to identify the causes and time to death of all trauma victims who died at a level I trauma center during an 11-year period. STUDY DESIGN Autopsies were performed on all patients who died secondary to trauma. Retrospective review of these autopsies was carried out and appended to existing trauma registry data. Standard definitions were used to attribute the cause of death in each case. Preventable deaths were determined by a standardized peer review process. RESULTS Between January 1985 and December 1995, a total of 900 trauma patients died. This represented 7.3% of all major trauma admissions (12,320). Seventy percent of these patients died within the first 24 hours of admission. Thoracic vascular and central nervous system (CNS) injuries were the most common causes of death in the first hour after admission to the hospital. CNS injuries were the most common causes of death within the 72 deaths after admission. Acute inflammatory processes (multiple organ failure, acute respiratory distress syndrome, and pneumonia) and pulmonary emboli were the leading causes of death after the first 72 hours. Overall, 43.6% (393 of 900) of all trauma deaths were caused by CNS injuries, making this the most common cause of death in our study. The preventable death rate was 1%. CONCLUSIONS The first 24 hours after trauma are the deadliest for these patients. Primary and secondary CNS injuries are the leading causes of death. Prevention, early identification, and treatment of potentially lethal injuries should remain the focus of those who treat trauma patients.Background: The purpose of this study was to identify the causes and time to death of all trauma victims who died at a level I trauma center during an 11-year period. Study Design: Autopsies were performed on all patients who died secondary to trauma. Retrospective review of these autopsies was carried out and appended to existing trauma registry data. Standard definitions were used to attribute the cause of death in each case. Preventable deaths were determined by a standardized peer review process. Results: Between January 1985 and December 1995, a total of 900 trauma patients died. This represented 7.3% of all major trauma admissions (12,320). Seventy percent of these patients died within the first 24 hours of admission. Thoracic vascular and central nervous system (CNS) injuries were the most common causes of death in the first hour after admission to the hospital. CNS injuries were the most common causes of death within the 72 deaths after admission. Acute inflammatory processes (multiple organ failure, acute respiratory distress syndrome, and pneumonia) and pulmonary emboli were the leading causes of death after the first 72 hours. Overall, 43.6% (393 of 900) of all trauma deaths were caused by CNS injuries, making this the most common cause of death in our study. The preventable death rate was 1%. Conclusions: The first 24 hours after trauma are the deadliest for these patients. Primary and secondary CNS injuries are the leading causes of death. Prevention, early identification, and treatment of potentially lethal injuries should remain the focus of those who treat trauma patients.

Hand-Held Thoracic Sonography for Detecting Post-Traumatic Pneumothoraces: The Extended Focused Assessment With Sonography For Trauma (EFAST)

BACKGROUND Thoracic ultrasound (EFAST) has shown promise in inferring the presence of post-traumatic pneumothoraces (PTXs) and may have a particular value in identifying occult pneumothoraces (OPTXs) missed by the AP supine chest radiograph (CXR). However, the diagnostic utility of hand-held US has not been previously evaluated in this role. METHODS Thoracic US examinations were performed during the initial resuscitation of injured patients at a provincial trauma referral center. A high frequency linear transducer and a 2.4 kg US attached to a video-recorder were used. Real-time EFAST examinations for PTXs were blindly compared with the subsequent results of CXRs, a composite standard (CXR, chest and abdominal CT scans, clinical course, and invasive interventions), and a CT gold standard (CT only). Charts were reviewed for in-hospital outcomes and follow-up. RESULTS There were 225 eligible patients (207 blunt, 18 penetrating); 17 were excluded from the US examination because of battery failure or a lost probe. Sixty-five (65) PTXs were detected in 52 patients (22% of patients), 41 (63%) being occult to CXR in 33 patients (14.2% whole population, 24.6% of those with a CT). The US and CXR agreed in 186 (89.4%) of patients, EFAST was better in 16 (7.7%), and CXR better in 6 (2.9%). Compared with the composite standard, the sensitivity of EFAST was 58.9% with a likelihood ratio of a positive test (LR+) of 69.7 and a specificity of 99.1%. Comparing EFAST directly to CXR, by looking at each of 266 lung fields with the benefit of the CT gold standard, the EFAST showed higher sensitivity over CXR (48.8% versus 20.9%). Both exams had a very high specificity (99.6% and 98.7%), and very predictive LR+ (46.7 and 36.3). CONCLUSION EFAST has comparable specificity to CXR but is more sensitive for the detection of OPTXs after trauma. Positive EFAST findings should be addressed either clinically or with CT depending on hemodynamic stability. CT should be used if detection of all PTXs is desired.

Original Scientific ArticlesLethal Injuries and Time to Death in a Level I Trauma Center 1

BACKGROUND The purpose of this study was to identify the causes and time to death of all trauma victims who died at a level I trauma center during an 11-year period. STUDY DESIGN Autopsies were performed on all patients who died secondary to trauma. Retrospective review of these autopsies was carried out and appended to existing trauma registry data. Standard definitions were used to attribute the cause of death in each case. Preventable deaths were determined by a standardized peer review process. RESULTS Between January 1985 and December 1995, a total of 900 trauma patients died. This represented 7.3% of all major trauma admissions (12,320). Seventy percent of these patients died within the first 24 hours of admission. Thoracic vascular and central nervous system (CNS) injuries were the most common causes of death in the first hour after admission to the hospital. CNS injuries were the most common causes of death within the 72 deaths after admission. Acute inflammatory processes (multiple organ failure, acute respiratory distress syndrome, and pneumonia) and pulmonary emboli were the leading causes of death after the first 72 hours. Overall, 43.6% (393 of 900) of all trauma deaths were caused by CNS injuries, making this the most common cause of death in our study. The preventable death rate was 1%. CONCLUSIONS The first 24 hours after trauma are the deadliest for these patients. Primary and secondary CNS injuries are the leading causes of death. Prevention, early identification, and treatment of potentially lethal injuries should remain the focus of those who treat trauma patients.Background: The purpose of this study was to identify the causes and time to death of all trauma victims who died at a level I trauma center during an 11-year period. Study Design: Autopsies were performed on all patients who died secondary to trauma. Retrospective review of these autopsies was carried out and appended to existing trauma registry data. Standard definitions were used to attribute the cause of death in each case. Preventable deaths were determined by a standardized peer review process. Results: Between January 1985 and December 1995, a total of 900 trauma patients died. This represented 7.3% of all major trauma admissions (12,320). Seventy percent of these patients died within the first 24 hours of admission. Thoracic vascular and central nervous system (CNS) injuries were the most common causes of death in the first hour after admission to the hospital. CNS injuries were the most common causes of death within the 72 deaths after admission. Acute inflammatory processes (multiple organ failure, acute respiratory distress syndrome, and pneumonia) and pulmonary emboli were the leading causes of death after the first 72 hours. Overall, 43.6% (393 of 900) of all trauma deaths were caused by CNS injuries, making this the most common cause of death in our study. The preventable death rate was 1%. Conclusions: The first 24 hours after trauma are the deadliest for these patients. Primary and secondary CNS injuries are the leading causes of death. Prevention, early identification, and treatment of potentially lethal injuries should remain the focus of those who treat trauma patients.

A prospective evaluation of abdominal ultrasound in blunt trauma: is it useful?

OBJECTIVE The purpose of this study is to evaluate the utility and feasibility of abdominal ultrasound (US) in blunt trauma patients. DESIGN This prospective study examined the operational issues and the diagnostic accuracy of US in selected blunt trauma patients triaged to a Level 1 trauma center. MATERIALS AND METHODS All patients were evaluated by an attending trauma surgeon and our usual criteria for objective evaluation of the abdomen were applied. US was performed by US technicians and interpreted by the trauma surgeon. We prospectively evaluated the availability (time to arrival), the ease with which the US could be integrated into the resuscitation (minutes to start after arrival), and the time required to perform the study. The US results were compared to diagnostic peritoneal lavage and computed tomography findings, clinical course, operative findings, and to repeat US examinations to determine sensitivity, specificity, and usefulness. MEASUREMENTS AND MAIN RESULTS A total of 800 US studies were performed over 15 months. In four cases (0.5%), the US was incomplete for technical reasons. The results in the remaining 796 studies were as follows: [table: see text] The average time to arrival of the US was 17.3 minutes (range 0-120) and the average minutes to start after arrival was 7.0 (range 1-49). The average time required to perform the study was 10.6 minutes (range 2-26). CONCLUSIONS This study demonstrates that US can be obtained rapidly, integrated into the resuscitation, and completed quickly. US provides a highly accurate, noninvasive method to evaluate the abdomen in the blunt trauma patient, and has supplanted the previously used methods at this institution.

Trauma in Pregnancy: Maternal and Fetal Outcomes

OBJECTIVE Pregnancy imposes significant physiologic demands that may confuse and complicate the evaluation, resuscitation, and definitive management of pregnant women who sustain trauma. Accurate prediction of fetal outcome after trauma remains elusive. The objective of this study was to characterize patterns of injury in pregnant women, to determine if pregnancy affects maternal morbidity and mortality after trauma, and to identify predictors of fetal death. METHODS We performed a retrospective, case-control analysis of all injured pregnant patients admitted to the Trauma Service at the University of California San Diego Medical Center from 1985 to 1995. RESULTS We identified 114 injured pregnant patients. Motor vehicle crashes accounted for 70% of injuries, and of these, 46% of patients were not using seat belts or helmets. Violence accounted for 12% of injuries. Injured pregnant women with Injury Severity Scores > 8 demonstrated similar mortality, morbidity, and length of stay to matched nonpregnant control patients. Pregnant women were more likely to sustain serious abdominal injury and were less likely to sustain severe head injury. Identified risk factors for fetal loss include maternal death, overall maternal injury severity, the presence of severe abdominal injury, and the presence of hemorrhagic shock. CONCLUSION There appears to be a group of pregnant women in San Diego at high risk for traumatic injury who should be targeted for preventative strategies including improved seat belt use. Pregnancy does not increase mortality or morbidity after trauma but influences the pattern of injury. Maternal death, high Injury Severity Score, serious abdominal injury, and hemorrhagic shock are risk factors for fetal loss.

Risk Factors Associated With Pulmonary Embolism Despite Routine Prophylaxis: Implications For Improved Protection

Despite prophylaxis, pulmonary embolism (PE) remains a major cause of posttraumatic morbidity and mortality in high-risk patients. We studied injury-related risk factors associated with the occurrence of PE despite routine prophylaxis. A review of 9721 trauma patients discharged from January 1, 1985 through December 31, 1992, identified 36 patients (0.4%) who suffered clinically evident PE despite a policy of routine prophylaxis against deep venous thrombosis that included use of prophylactic inferior vena caval filters. (Twenty-nine patients had an inferior vena caval filter placed for prophylaxis against PE.) A detailed analysis of injury-related risk factors was performed. Four high-risk patterns of injury were identified, representing common combinations of significant risk factors. These patient groups have an absolute risk of PE despite prophylaxis ranging from 1.5% to 3.8%. The relative risk is approximately ten times that of control patients. Identification of appropriate high-risk groups is necessary to allow optimization of prophylactic measures, including placement of inferior vena caval filter.

Intra-abdominal free fluid without solid organ injury in blunt abdominal trauma: an indication for laparotomy.

BACKGROUND The optimal management of patients sustaining blunt abdominal trauma (BAT), in whom intra-abdominal free fluid but no solid organ injury is found on imaging, remains unclear. The purpose of this study was to determine the incidence and significance of this finding. METHODS All patients presenting with suspected BAT to a provincial trauma center over a 30-month period were reviewed. A screening focused abdominal sonogram for trauma scan was obtained in every case. Stable patients with positive or indeterminate scans underwent computed tomographic scanning. Those with free fluid but without visible solid organ injury were studied. Radiologic interpretation, clinical management, and operative findings were analyzed. RESULTS Twenty-eight of 1,367 patients (2%) met inclusion criteria. Twenty-one patients (75%) underwent exploratory laparotomy, which for 16 (76%) was therapeutic: bowel injuries were found in 10 patients, mesentery injuries in 6, and injuries to solid organs in 3. In five patients, laparotomy was nontherapeutic. Those with more than a trace of free fluid were significantly more likely to have a therapeutic procedure. Seven patients (25%) were observed, of whom two failed nonoperative management and underwent therapeutic laparotomies within 24 hours of admission for missed colon, splenic, and hepatic injuries. The presence of abdominal seat belt bruising or a Chance-type fracture in the study patients was associated with a 90% and 100% therapeutic laparotomy rate, respectively. Computed tomographic scan findings were variable and were not able to predict injury severity or need for surgery. CONCLUSION The finding of more than trace amounts of free fluid in the absence of solid organ injury in BAT is often associated with clinically significant visceral injury. Early laparotomy is recommended for these patients.

The hand-held FAST: experience with hand-held trauma sonography in a level-I urban trauma center.

AIMS To describe the effectiveness of a portable hand-held ultrasound machine when used by clinicians in the early evaluation and resuscitation of trauma victims. METHODS The study was a prospective evaluation in a level-I urban trauma center. The focussed assessment with sonography for trauma is a specifically defined examination for free fluid known as the focused assessment with sonography for trauma (FAST) exam. Seventy-one patients had a hand-held FAST (HHFAST) examination performed with a Sonosite 180, 2.4 kg ultrasound machine. Sixty-seven examinations were immediately repeated with a Toshiba SSH 140A portable floor-based machine. This repeat scan (formal FAST or FFAST) was used as a comparison standard between the devices for study purposes. Four patients had a HHFAST only, all with positive result, two being taken for immediate laparotomy, and two having a follow-up computed tomographic (CT) scan. Patient follow-up from other imaging studies, operative intervention, and clinical outcomes were also compared to the performance of each device. RESULTS There were 58 victims of blunt, and 13 of penetrating abdominal trauma. One examination was indeterminate using both machines. The apparent HHFAST performance yielded; sensitivity, specificity, positive predictive value, negative predictable value, and accuracy (S, S, PPV, NPV, A) of 83, 100, 100, 98, 98%. Upon review, a CT scan finding and benign clinical course found the HHFAST diagnosis to be correct rather than the FFAST in one case. Considering the ultimate clinical course of the patients, yielded a (S, S, PPV, NPV, A) of 78, 100, 100, 97, and 97% for the HHFAST and 75, 98, 86, 97, and 96% for the FFAST. Statistically, there was no significant difference in the actual performance of the HHFAST compared to the FFAST in this clinical setting. DISCUSSION Hand-held portable sonography can simplify early and accurate performance of FAST exams in victims of abdominal trauma.

Acute lung injury in endotoxemic rats is associated with sustained circulating IL-6 levels and intrapulmonary CINC activity and neutrophil recruitment--role of circulating TNF-alpha and IL-beta?

Endotoxemia initiates a cytokine response that is thought to mediate the syndromes of sepsis and multiple organ failure. This study measured cytokine levels in the blood and airways of rats at critical time points during the development of lung injury induced by chronic endotoxin (LPS) infusion in the rat. Tumor necrosis factor-alpha (TNF), interleukin-1-beta (IL-1), and interleukin-6 (IL-6) were measured in the blood and bronchoalveolar lavage fluid (BALF) of endotoxemic and control animals. BALF was also studied for the percentage of neutrophil (PMN) count and chemotactic activity. Lung histology was determined at 72 h following infusion of LPS. Chronic endotoxemia of > or = 48 h but not < or = 24 h resulted in severe acute lung injury (ALI). Circulating levels of TNF and IL-1 were only transiently elevated, whereas IL-6 remained elevated in the endotoxemic rats. TNF, IL-1, and IL-6 levels in BALF were only transiently elevated. Chemotactic activity, levels of cytokine-induced neutrophil chemoattractant (CINC), and the percentage of PMN counts in BALF all increased significantly by 36 h. Other potential chemoattractants; leukotriene B4 and transforming growth factor-beta were not elevated in BALF. In conclusion, severe ALI requires a minimum of 48 h LPS infusion in this model and is associated with high levels of circulating IL-6, increased CINC activity, and an increased percentage of PMN count in BALF. Local inflammatory events may be as important as the systemic cytokine milieu in mediating ALI. The signal for these local events does not appear to depend solely on the transient elevations of circulating TNF and IL-1 at the onset of endotoxemia, although sustained high levels of IL-6 may be important.

Sonographic Diagnosis of a Pneumothorax Inapparent on Plain Radiography: Confirmation by Computed Tomography

The focused assessment with sonography for trauma (FAST) consists of imaging the perihepatic, pelvic, perisplenic, and pericardial locations for the presence of free fluid.1,2 Although the pleural spaces may similarly be sonographically evaluated for pleural fluid using sonography,3 the FAST examination has not routinely been used to exclude pneumothorax. Traumatic pneumothorax is a frequent cause of preventable trauma death. Pneumothoraces are usually detected through clinical examination supplemented with plain chest radiographs. Most radiographs initially obtainable in severe blunt trauma settings are anteroposterior (AP) supine films because of concerns regarding spinal injury. In the supine patient, a pneumothorax is usually suggested by the presence of a deep sulcus sign, or the crisp definition of the pericardial silhouette.4 We describe the diagnosis of a small pneumothorax by thoracic ultrasound with computed tomographic (CT) confirmation in a patient after blunt trauma who had a nondiagnostic chest radiograph.