Robert A. Read

Epidemiology of trauma deaths : a reassessment

OBJECTIVE Recognizing the impact of the 1977 San Francisco study of trauma deaths in trauma care, our purpose was to reassess those findings in a contemporary trauma system. DESIGN Cross-sectional. MATERIAL AND METHODS All trauma deaths occurring in Denver City and County during 1992 were reviewed; data were obtained by cross-referencing four databases: paramedic trip reports, trauma registries, coroner autopsy reports and police reports. MEASUREMENTS AND MAIN RESULTS There were 289 postinjury fatalities; mean age was 36.8 +/- 1.2 years and mean Injury Severity Score (ISS) was 35.7 +/- 1.2. Predominant injury mechanisms were gunshot wounds in 121 (42%), motorvehicle accidents in 75 (38%) and falls in 23 (8%) cases. Seven (2%) individuals sustained lethal burns. Ninety eight (34%) deaths occurred in the pre-hospital setting. The remaining 191 (66%) patients were transported to the hospital. Of these, 154 (81%) died in the first 48 hours (acute), 11 (6%) within three to seven days (early) and 26 (14%) after seven days (late). Central nervous system injuries were the most frequent cause of death (42%), followed by exsanguination (39%) and organ failure (7%). While acute and early deaths were mostly due to the first two causes, organ failure was the most common cause of late death (61%). CONCLUSIONS In comparison with the previous report, we observed similar injury mechanisms, demographics and causes of death. However, in our experience, there was an improved access to the medical system, greater proportion of late deaths due to brain injury and lack of the classic trimodal distribution.

Gut ischemia/reperfusion produces lung injury independent of endotoxin

ObjectiveBacterial translocation from the gut has been invoked as a common inciting event for postinjury multiple organ failure. We previously showed that gut ischemia/reperfusion induces remote organ injury. The purpose of this study was to ascertain if endotoxin has a pivotal mechanistic role in this process. DesignProspective, randomized study. SettingAnimal laboratory. SubjectsSprague-Dawley rats weighing 300 to 350 g. InterventionsAnesthetized animals underwent 45 mins of superior mesenteric artery occlusion and 2 hrs of reperfusion; sham laparotomy served as controls. Endotoxin was eliminated with the murine immunoglobulin (Ig) M antibody E5, 3 mg/kg iv before the study. Measurements and Main ResultsPlasma endotoxin was measured by the limulus amebocyte lysate assay. At 2 hrs of reperfusion, circulating neutrophil priming was determined by the difference in superoxide generation with and without the activating stimulus, N-formyl-Met-Leu-Phe. Neutrophil sequestration in the lung was quantitated by myeloperoxidase activity, and by lung endothelial permeability by 125I albumin lung/blood ratio. Endotoxin concentrations were not significantly (significance determined as p < .05) different between the gut ischemia/reperfusion and laparotomy groups (n = ≥5) during ischemia or reperfusion. Circulating neutrophil priming, neutrophil accumulation in the lung, and lung injury were provoked by gut ischemia/reperfusion, but not altered by endotoxin elimination. ConclusionGut ischemia/reperfusion primes circulating neutrophils and produces lung injury by a mechanism independent of endotoxin. (Crit Care Med 1994; 22:1438–1444)

Cardiac enzymes are irrelevant in the patient with suspected myocardial contusion

BACKGROUND Myocardial contusion is commonly diagnosed following blunt chest trauma, and has potentially lethal complications. Cost-effective case management in patients with suspected myocardial contusion is confounded by the low incidence of complications and the lack of a reliable test to predict them. The clinical usefulness of elevated cardiac enzyme levels is controversial. METHODS We analyzed a 4-year experience of 359 patients with high-risk blunt chest trauma who were assessed using an established practice guideline. Our multivariate statistical model evaluated all of the early risk factors included in the guideline, specifically focusing on cardiac enzyme levels. RESULTS Myocardial contusion was diagnosed in 30% of patients, and complications (dysrhythmias and cardiogenic shock) occurred in 5%. In no case was cardiac enzyme elevation the sole predictor of a complication. The cost of routine cardiac enzyme assay was substantial. CONCLUSION Cardiac enzyme determinations have no useful role in the evaluation of patients with suspected myocardial contusion. They should be eliminated from current practice guidelines.

Diagnosing pneumonia in mechanically ventilated trauma patients: endotracheal aspirate versus bronchoalveolar lavage.

We prospectively investigated the diagnostic value of semiquantitative (semiQC) and quantitative (QC) cultures of endotracheal aspirate (ETA) compared with QC of bronchoalveolar lavage (BAL) fluids in 18 mechanically ventilated trauma patients with clinical signs of pneumonia. The general agreement between QC of ETA and BAL was 89% when conventional cutoffs for the QC were used and 94% if the cutoffs were adjusted for previous antibiotic therapy. In all six patients whose clinical diagnoses of pneumonia were considered definite, both QC of ETA and QC of BAL were positive; however, standard semiQC of ETA showed comparable results in this group. On the contrary, in the 12 patients whose clinical diagnoses were uncertain, QC of BAL and ETA were negative in ten patients and in five (50%) of these, pneumonia was eventually excluded. Semiquantitative cultures of ETA were positive in all these patients. Five (28%) patients experienced a decrease in PaO2/FiO2 (> 15% of previous value) 2 hours after BAL, and in three (17%) this derangement persisted for 24 hours. These data suggest that BAL may be hazardous in mechanically ventilated trauma patients and that its use should be restricted to patients in whom the diagnosis is in doubt.

Balloon tamponade for bilobar transfixing hepatic gunshot wounds.

The nonresectional approach to major liver trauma is clearly preferred. Unfortunately, trachotomy with vessel ligation, selective hepatic arterial ligation, perihepatic pack, and fibrin glue are not viable options with high-energy bilobar liver injuries. We have fashioned a balloon tamponade device that has proved very effective for these transfixing hepatic gunshot wounds.

Pneumonia: Cause or symptom of postinjury multiple organ failure?

Recent studies have shown that selective gut decontamination can reduce the incidence of pneumonia, but this does not decrease multiple organ failure (MOF) or mortality. These findings have prompted the hypothesis that pneumonia is an inconsequential symptom of MOF. To test this, we prospectively evaluated 123 high-risk trauma patients (mean Injury Severity Score = 36.2 +/- 1.5). Organ dysfunction, scored daily according to a 12-point scale, ultimately developed in 28 (23%) patients. Major infections were diagnosed, based on strict criteria, in 59 patients (48%), and pneumonia developed in 52 patients (43%). Pneumonia was significantly associated with MOF (82% of patients with MOF versus 30% of patients without MOF, p < 0.0001). In 14 (50%) of the patients with MOF, pneumonia preceded a significant rise (greater than or equal to 3) in serial MOF scoring. Of note, 10 (71%) of these patients died. Among the remaining 14 patients with MOF, 10 developed pneumonia, but this was associated with a minimal increase (less than or equal to 2) in MOF scoring (3 patients died). These data, by temporal association with MOF scoring, implicate pneumonia in precipitating or significantly worsening organ failure in 50% of the patients who developed MOF.

Trauma surgeons can render definitive surgical care for major thoracic injuries.

Restrictions on the operative domain of general surgeons threaten the viability of trauma surgery as a career choice. Our study hypothesis is that an experienced trauma surgeon can provide definitive care for life-threatening thoracic trauma. This analysis is based on clinical outcomes at an ACS-verified level I center in which there are more than 3000 trauma admissions managed annually under the direction of four academic trauma surgeons. We selected penetrating cardiac wounds and blunt tears of the thoracic aorta because these injuries are managed exclusively by the trauma service and the endpoints are distinct. During the past 4 years, 40 patients with cardiac wounds were delivered to the ED; 23 patients arrived dead. In the remaining 17, injury mechanisms were 15 stab wounds (SW), one gunshot wound (GSW), and one shotgun (SGW). Four of these patients required ED thoracotomy, and the remaining 13 underwent some form of prethoracotomy pericardial decompression. Survival rate without neurologic deficit was 94% (16 of 17). During this same period, 19 patients with a torn thoracic aorta from blunt injuries arrived with signs of life. In this group the injury mechanisms were automobile crash in 15, and the mean ISS was 39.7 +/- 2.3. One patient was transferred for total cardiopulmonary bypass; 17 of the remaining patients underwent aortic repair employing partial left heart bypass. Sixteen of our 18 patients lived and none developed paraplegia. In summary, excluding patients who arrived dead, survival for penetrating cardiac wounds was 94% and for blunt thoracic aortic tears 89%. In conclusion, these data support our contention that trauma surgeons can render definitive care for thoracic injuries with survival rates comparable to those reported by cardiothoracic surgeons.

Extrapleural bupivacaine for amelioration of multiple rib fracture pain

OBJECTIVE The pain associated with multiple rib fractures can be surprisingly variable. The objective of this study was to determine the efficacy of an indwelling, percutaneously placed intercostal catheter in relieving the pain associated with multiple rib fractures. DESIGN Prospective nonrandomized study setting: Surgical intensive care unit in a level 1 trauma center. SUBJECTS Fifteen blunt chest trauma patients with a minimum of three rib fractures who had failed an intravenous patient controlled analgesia protocol. INTERVENTIONS Insertion of an epidural catheter within the intercostal space. Bupivacaine 0.25% with epinephrine was injected in a volume of 20 mL. Subsequent doses were limited to a total of 400 mg per 24 hours. MEASUREMENTS AND MAIN RESULTS Severity of injury was estimated by using the Injury Severity Score. For each patient a preinjection visual analogue scale (VAS) and incentive spirometry (IS) lung volume were determined. Fifteen minutes following injection of 0.25% bupivacaine with epinephrine the VAS and IS were repeated. The Injury Severity Score ranged from 9 to 32 (mean 19.0 +/- 1.6). Overall, mean VAS pain scores improved significantly following the initial bolus of bupivacaine (before VAS = 7.5 +/- 0.6, after VAS = 3.5 +/- 0.5, p < 0.05) and this was associated with significant increase in IS lung volumes (before IS = 0.77 +/- 0.09, after IS = 1.3 +/- 0.13, p < 0.05). No patient experienced either insertion-related or drug administration complications. CONCLUSIONS These results confirm that an indwelling intercostal catheter provides a continuous nerve block resulting in a simple, safe procedure that can ameliorate the pain and splinting associated with multiple rib fractures. Although we experienced no complications, additional investigation is clearly needed.

Improved cannulation method for extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation has been shown to be useful for patients in reversible cardiogenic shock. Effective arterial cannulation techniques for infants have been developed that are simple to use and require minimal subsequent vascular repair or reconstruction after removal. Groin cannulation in adults frequently requires bidirectional arterial cannulation to ensure adequate distal perfusion as well as frequent complex arterial repairs after discontinuation. We describe a simple arterial cannulation technique using a single right-angle, high-flow arterial cannula. With this technique adequate bidirectional arterial perfusion is maintained with a single arterial cannula while the need for vascular repairs or reconstruction is minimized.

Bronchial Anomaly of the Right Upper Lobe

This case report presents a rare anomaly of right upper lobe bronchial anatomy. During routine right upper lobe resection for carcinoma, a common right upper and middle lobe bronchus was found. The resection was completed as a right upper and middle bilobectomy. Knowledge of this uncommon variant was beneficial in performing the pulmonary resection. A review of the literature is presented.