David H. Livingston

Isolated traumatic brain injury: age is an independent predictor of mortality and early outcome.

BACKGROUND Geriatric trauma patients have a worse outcome than the young with comparable injuries. The contribution of traumatic brain injury (TBI) to this increased mortality is unknown and has been confounded by the presence of other injuries. The purpose of this study was to investigate the role of age in the mortality and early outcome from isolated TBI. METHODS This was a retrospective analysis of all adult patients with isolated TBI (Abbreviated Injury Scale score > or = 3) admitted during a 5-year period to two Level I trauma centers. Mortality, Glasgow Outcome Scale score at discharge, therapy, and complications were compared for elderly (age > or = 65 years) and younger patients. RESULTS Of 694 patients, 22% were defined as elderly. The mortality for the elderly group was twice that of their younger counterparts (30% vs. 14%, p < 0.001), even for those with mild to moderate TBI (Glasgow Coma Scale score of 9-15). Thirteen percent of elderly survivors had a poor functional outcome (Glasgow Outcome Scale score of 2 or 3) at hospital discharge versus 5% in the young group (p < 0.01). Independent factors associated with a high mortality were age and Glasgow Coma Scale score. CONCLUSION The mortality from TBI is higher in the geriatric population at all levels of head injury. In addition, functional outcome at hospital discharge is worse. Although some of this increased mortality may be explained by complications or type of head injury, age itself is an independent predictor for mortality in TBI.

The effect of age on functional outcome in mild traumatic brain injury: 6-month report of a prospective multicenter trial

OBJECTIVE Elderly patients (aged 60 years and older) have been demonstrated to have an increased mortality after isolated traumatic brain injury (TBI); however, the prognosis of those patients surviving their hospitalization is unknown. We hypothesized that surviving elderly patients would also have decreased functional outcome, and this study examined the functional outcome of patients with isolated TBI at discharge and at 6 months posthospitalization. METHODS This was a multicenter prospective study of all patients with isolated moderate to severe TBI defined as Head Abbreviated Injury Scale score of 3 with an Abbreviated Injury Scale score in any other body area of 1. Patients surviving to discharge gave their consent and were enrolled. Data collected included demographics, Glasgow Coma Scale (GCS) score at admission, and neurosurgical interventions. Outcome data included discharge disposition and Glasgow Outcome Scale score and modified Functional Independence Measure (FIM) score at discharge and at 6 months. RESULTS Two hundred thirty-five patients were enrolled, with 44 (19%) aged greater than or equal to 65 years. Mechanisms of injury were falls (34%), assaults (28%), motor vehicle collisions (14%), pedestrian (11%), and other (12%). Falls were more common in the older patients and assaults in the younger group. The mean admitting GCS score was 12.8 (95% confidence interval [CI], 12.4-13.3), with older patients having a higher mean GCS score, 14.1 (95% CI, 13.6-14.6) versus 12.5 (95% CI, 12.0-13.1; p = 0.03). There were no differences in the percentage of patients admitted to the intensive care unit or requiring neurosurgical intervention between younger and older patients. Because there were few elderly patients with low GCS scores who survived to discharge, outcome measures focused on those patients with GCS scores of 13 to 15. A greater percentage of elderly were discharged to rehabilitation (28% vs. 16%, p =0.08). The mean discharge FIM score was 10.4 (95% CI, 9.8-11.0) for the elderly versus 11.4 (95% CI, 11.1-11.7) for the young (p =0.001), with 68% elderly and 89% young discharged with total independent scores of 11 to 12. At 6 months, the difference narrowed, but the mean FIM score was still greater for the young group, 11.7 (95% CI, 11.6-11.9) versus 11.0 (95% CI, 10.6-11.4; p < 0.001). CONCLUSION Functional outcome after isolated mild TBI as measured by the Glasgow Outcome Scale and modified FIM is generally good to excellent for both elderly and younger patients. Older patients required more inpatient rehabilitation and lagged behind their younger counterparts but continued to recover and improve after discharge. Although there were statistically significant differences in the FIM score at both discharge and 6 months, the clinical importance of these small differences in the mean FIM score to the patients quality of life is less clear. Measurable improvement in functional status during the first 6 months after injury is observed in both groups. Aggressive management and care of older patients with TBI is warranted, and efforts should be made to decrease inpatient mortality. Continued follow-up is ongoing to determine whether these outcomes persist at 12 months.

Angiographic embolization for liver injuries: low mortality, high morbidity.

OBJECTIVE Angiographic embolization (AE) is a safe and effective method for controlling hemorrhage in both blunt and penetrating liver injuries. Improved survival after hepatic injuries has been documented using a multimodality approach; however, patients still have significant long-term morbidity. This study examines further the role of AE in both blunt and penetrating liver injuries and the outcomes of its use. METHODS The medical records of 37 consecutive patients admitted from 1995 to 2002 to a Level I trauma center who underwent hepatic angiography with the intent to embolize were reviewed. Demographic and clinical information including Injury Severity Score, length of stay, mortality, intra-abdominal complications, admission physiologic variables, and the number and type of abdominal operations performed were collected. RESULTS Thirty-seven patients underwent hepatic angiography and 26 patients had hepatic embolization performed. Eleven patients underwent early-AE, immediately after computed tomographic scanning, and 15 underwent late-AE, after liver-related operations or later in their hospital course. There was a 27% mortality rate overall. There were 11 liver-related complications in the 26 embolizations. Excluding the early deaths, the associated morbidity was 58%, which included hepatic necrosis, hepatic abscesses, and bile leaks. CONCLUSION There is increasing adjunctive use of AE in patients managed both operatively and nonoperatively. Intra-abdominal complications are common in these salvaged patients with severe liver injuries. Those patients that underwent early-AE received significantly fewer blood transfusions and more commonly had sterile hepatic collections. Only 26% of patients required liver-related surgery after AE. Therefore, the integration of AE as an adjunctive modality for patients with high-grade liver injuries is a safe and effective therapeutic option.

Admission or Observation Is Not Necessary after a Negative Abdominal Computed Tomographic Scan in Patients with Suspected Blunt Abdominal Trauma: Results of a Prospective, Multi-institutional Trial

OBJECTIVES Hospitalization for observation is the current standard of practice for patients who have sustained blunt abdominal trauma and who do not require emergent operation, despite having undergone diagnostic studies that exclude the presence of an intra-abdominal injury. The reasons for this practice are multifactorial and include the perceived false-negative rate of all standard diagnostic tests, the belief that hospitalization will allow for the prompt diagnosis of occult injuries, and medicolegal considerations about the risk of early discharge. The focus of this study was to determine whether hospitalization for observation is necessary after a negative diagnostic evaluation after blunt abdominal trauma, to determine the negative predictive value of abdominal computed tomographic (CT) scanning in a prospective series of patients, and to identify which patients can be safely released from the emergency department without observation or hospitalization after blunt abdominal trauma. METHODS In a prospective, multi-institutional study over 22 months at four Level I trauma centers, all patients with blunt abdominal trauma suspected by either physical examination or mechanism of injury were evaluated using the following protocol: physical examination in the emergency department, followed by abdominal CT scanning, followed by hospitalization for observation. The standardized physical examination was repeated between 4 and 8 hours. Outcomes were measured at 20 hours and at discharge and included clinical deterioration, the need for celiotomy, and mortality. Other data collected included demographics, mechanism of injury, and findings on physical examination and abdominal CT scanning. RESULTS Three thousand eight hundred twenty-two consecutive patients with suspected abdominal trauma presented to the four trauma centers. Two thousand seven hundred seventy-four of these met study eligibility criteria and were prospectively enrolled. Of these, 2299 fulfilled the entire study protocol. CT scan was negative in 1,809 patients, positive for organ injury or abdominal fluid in 389 patients, and nondiagnostic in 78 patients. Abdominal tenderness or bruising was present in 1,380 patients (61%), but only 22% had a positive CT scan. Nineteen percent of patients with a positive CT scan had no tenderness. Computed tomography detected 22 of the 25 blunt intestinal injuries in this series. Free intraperitoneal fluid without solid visceral injury was present in 90 patients, and but only 7 patients had intestinal injuries. There were nine celiotomies in patients whose CT scan was initially interpreted as negative: six were therapeutic (intestine in three, bladder in one, kidney in one, and diaphragm in one), two were nontherapeutic, and one was negative. The negative predictive power of an abdominal CT scan based on the preliminary reading and as defined by the subsequent need for a celiotomy in the population fully satisfying the protocol was 99.63% (lower 95 and 99% confidence bounds of 99.31 and 99.16%, respectively). CONCLUSION These data indicate that abdominal tenderness is not predictive of an abdominal injury and that patients with a negative CT scan after suspected blunt abdominal trauma do not benefit from hospital admission and prolonged observation.

A randomized prospective clinical trial to determine the efficacy of interferon-γ in severely injured patients

Many aspects of the normal immune response are depressed after severe injury. Reduced monocyte human leukocyte antigen-DR (HLA-DR) levels have closely correlated with the development of major infection. After a pilot study with recombinant interferon-gamma (rIFN-gamma) showed restoration of depressed HLA-DR levels after major injury, a multicenter, prospective, randomized, double-blind trial was conducted. Two hundred thirteen trauma patients who were at high risk of infection received either placebo or rIFN-gamma (100 micrograms) subcutaneously each day for 10 days after admission. One hundred ninety-three patients were evaluable with respect to primary end points. Patients treated with rIFN-gamma were older (p = 0.10) and had more severe modes of injury (p = 0.02). By the third day, both monocyte HLA-DR antigen expression and outcome predictive score were significantly better in the rIFN-gamma-treated group than in the placebo group (p = 0.0001 and p = 0.0006, respectively). Nine deaths occurred in patients treated with rIFN-gamma compared with 12 deaths in the placebo group (p = 0.46). Major infections requiring surgical drainage or debridement occurred in 17 patients treated with rIFN-gamma compared with 22 treated with placebo. No difference between treatment arms was noted in overall major or minor infection rates, but there were fewer severe infections that required reoperation or computer tomographic-guided drainage in patients receiving IFN-gamma. While these results suggest that rIFN-gamma may be useful in some aspects of infection in the patient with severe trauma, a larger trial with longer treatment will be needed to prove the comprehensive value of rIFN-gamma.

The utility of venous lactate to triage injured patients in the trauma center.

BACKGROUND Field triage criteria for trauma patients results in over-triage rates of 30% to 50% to achieve under-triage rates of 10%. This large number of patients may stress trauma center resources. Elevated arterial lactate (ALAC) levels have been shown to be a marker of serious injury but the need for arterial sampling limits the utility of the determination. The goal of this study was: 1) to determine the correlation between venous lactate (VLAC) and ALAC; 2) to determine whether VLAC could identify those patients with serious injuries; and 3) to compare an elevated VLAC level against standard triage criteria (STC) in their ability to identify major injury. STUDY DESIGN Arterial and venous samples for blood gas and lactate analyses were obtained in 375 patients within 10 minutes of patient arrival to the trauma center. Arterial and venous samples were drawn within 2 minutes of each other, placed on ice, and analyzed within 10 minutes of sampling. The location of sampling was left to physician discretion. Data collected included injury mechanism, demographics, admission vital signs, emergency department disposition, length of stay, and injury severity scores (ISS). Admission to the ICU, need for emergency operation, length of stay, and death were noted. Emergency medical service staff were queried to determine which standard triage criteria (STC) were fulfilled. RESULTS The mean ALAC was 3.11 mmol/L (SD 3.45, 95% confidence interval [CI] 2.67 to 3.55) and mean VLAC was 3.43 mmol/L (SD 3.41, 95% CI 2.96 to 3.90). There was no significant difference between ALAC and VLAC. The correlation between ALAC and VLAC was 0.94 (95% CI 0.94 to 0.96, p = 0.0001). An elevated VLAC predicted moderate to severe injury and there was a significant association between an increased lactate and maximum Abbreviated Injury Score (AIS) of 4 and 5 (ANOVA, F = 8.26, p < 0.001). Patients with VLAC > or =2 mmol/L had significantly increased relative risks of ISS > or = 13, death, admission to the ICU, and length of stay > 2 days. In comparison with STC, a VLAC > or = 2 mmol/L decreased undertriage in patients with ISS > or = 13 by one half (11% versus 24%) for patients with ISS > or = 13 and decreased over-triage by 28% (46% versus 64%). These data were most pronounced for patients injured in motor vehicle collisions. CONCLUSIONS VLAC is an excellent approximation for ALAC. A VLAC > or = 2 mmol/L appears to predict an ISS > or = 13, the need for ICU resources, and prolonged hospital stays. VLAC was significantly better than STC in all patients and was most useful in victims of blunt trauma, especially motor vehicle collisions.

Emergency Department Discharge of Patients With a Negative Cranial Computed Tomography Scan After Minimal Head Injury

OBJECTIVE To determine the negative predictive value of cranial computed tomography (CT) scanning in a prospective series of patients and whether hospital admission for observation is mandatory after a negative diagnostic evaluation after minimal head injury (MHI). SUMMARY BACKGROUND DATA Hospital admission for observation is a current standard of practice for patients who have sustained MHI, despite having undergone diagnostic studies that exclude the presence of an intracranial injury. The reasons for this practice are multifactorial and include the perceived false-negative rate of all standard diagnostic tests, the belief that admission will allow prompt diagnosis of occult injuries, and medicolegal considerations about the risk of early discharge. METHODS In a prospective, multiinstitutional study during a 22-month period at four level I trauma centers, all patients with MHI were evaluated using the following protocol: a standardized physical and neurologic examination in the emergency department, cranial CT scanning, and then admission for observation. MHI was defined as either a documented loss of consciousness or evidence of posttraumatic amnesia and an emergency department Glasgow Coma Scale score of 14 or 15. Outcomes were measured at 20 hours and at discharge and included clinical deterioration, need for craniotomy, and death. RESULTS Two thousand one hundred fifty-two consecutive patients fulfilled the study protocol. The CT was interpreted as negative for intracranial injury in 1,788, positive in 217, and equivocal in 119. Five patients with CT scans initially interpreted as negative required intervention. There was one craniotomy in a patient whose CT scan was initially interpreted as negative. This patient had facial fractures that required surgical intervention and elevation of depressed intracranial fracture fragments. The negative predictive power of a cranial CT scan based on the preliminary reading of the CT scan and defined by the subsequent need for neurosurgical intervention in the population fully satisfying the protocol was 99.70%. CONCLUSIONS Patients with a cranial CT scan, obtained on a helical CT scanner, that shows no intracerebral injury and who do not have other body system injuries or a persistence of any neurologic finding can be safely discharged from the emergency department without a period of either inpatient or outpatient observation. Implementation of this practice could result in a potential decrease of more than 500,000 hospital admissions annually.

Bone Marrow Failure Following Severe Injury in Humans

Background: Hematopoietic failure has been observed in experimental animals following shock and injury. In humans, bone marrow dysfunction has been observed in the red cell component and characterized by a persistent anemia, low reticulocyte counts, and the need for repeated transfusions despite adequate iron stores. While a quantitative defect in white blood cell count has not been noted, an alteration in white blood cell function manifesting as an increased susceptibility to infection is well established. Since the etiology of this anemia remains unknown and the bone marrow has been rarely studied following injury, we measured various parameters of hematopoiesis directly using bone marrow from trauma patients and tested the hypothesis that trauma results in profound bone marrow dysfunction, which could explain both the persistent anemia and the alteration in white blood cell function. Methods: Bone marrow aspirates and peripheral blood were obtained between day 1 and 7 following injury from 45 multiple trauma patients. Normal volunteers served as controls. Peripheral blood was assayed for hemoglobin concentration, reticulocyte count, erythropoietin levels, white blood cell count, and differential. Peripheral blood and bone marrow were cultured for hematopoietic progenitors (CFU-GM, BFU-E, and CFU-E colonies). Results: Bone marrow CFU-GM, BFU-E, and CFU-E colony formation was significantly reduced while peripheral blood CFU-GM, BFU-E, and CFU-E was increased in the trauma patients compared with normal volunteers. Bone marrow stroma failed to grow to confluence by day 14 in >90% of trauma patients. In contrast, bone marrow stroma from volunteers always reached confluence between days 10 and 14 in culture. The mean hemoglobin concentration and reticulocyte counts of the trauma patients were 8.6 ± 1.0 g/dL and 2.75 ± 0.7% respectively, while their plasma erythropoietin levels were 2 to 10 times greater than control values. Conclusions: Release of immature white blood cells into the circulation may also contribute to a failure to clear infection and an increased propensity to organ failure. Concomitantly, profound changes occur within the bone marrow, which include the increased release of erythroid and myeloid progenitors into the circulation, a decrease in progenitor cell growth within the bone marrow, and an impaired growth of the bone marrow stroma. Erythropoietin levels are preserved following trauma, implying that the persistent anemia of injury is related to the failure of the bone marrow to respond to erythropoietin.

The role of lymph factors in lung injury, bone marrow suppression, and endothelial cell dysfunction in a primate model of trauma-hemorrhagic shock.

Studies in rodent models of trauma-hemorrhagic shock (T/HS) have shown that factors contained in the intestinal lymph are responsible for acute lung injury and bone marrow suppression, and that they contribute to a systemic inflammatory state. Because results observed in rodent T/HS models may not fully reflect the response of injured patients, it is necessary to determine if these results can be replicated in primates before the institution of invasive studies in humans. Thus, the three goals of this study were to determine if diversion of thoracic duct lymph reduced T/HS-induced lung injury; to compare the biologic activity of thoracic duct lymph from baboons subjected to T/HS or trauma sham-shock (T/SS); and to compare the biologic activity and composition of plasma from baboons subjected to T/SS, T/HS, and T/HS with thoracic duct lymph drainage. Three groups of baboons were studied: T/SS plus lymph diversion via a thoracic duct catheter, T/HS, and T/HS plus lymph diversion (T/HS-LD). The trauma component consisted of a neck dissection with resection of the proximal clavicle plus a laparotomy. HS was to a mean arterial pressure of 40 mmHg and was maintained at 40 mmHg until the base excess reached −5 mEq or the total shock period reached 3 h. Volume resuscitation was carried out by reinfusing the shed blood plus crystalloids. Before, during, and after the T/HS or T/SS period, blood and lymph samples were obtained for analysis, and lung samples were harvested for measurement of lung wet-to-dry ratio at 5 h after the end of the shock period. Diversion of thoracic duct lymph prevented T/HS-induced lung injury as reflected in lung wet-to-dry weight ratios (T/SS = 4.6 ± 0.5; T/HS+LD = 4.8 ± 0.7; T/HS = 5.4 ± 0.6; P < 0.05). Lymph from the T/HS group collected during the early postshock period was cytotoxic for human endothelial cells (HUVECs; 16% vs. 100% survival in T/SS lymph) and increased HUVEC monolayer permeability almost 2-fold (P < 0.01). T/HS lymph and plasma also suppressed red blood cell (erythroid burst-forming unit) and white blood cell (granulocyte-monocyte colony-forming unit) progenitor cell growth of human bone marrow to ∼50% of control, whereas T/SS lymph and plasma were not suppressive (P < 0.05). Plasma cytokine levels were increased to a similar degree in the two T/HS groups. Thus, in a primate model of T/HS, gut-derived factors carried in the lymph potentiates lung injury and endothelial dysfunction, and suppresses bone marrow progenitor cell growth.

CT diagnosis of Rib fractures and the prediction of acute respiratory failure.

BACKGROUND The number of rib fractures has been reported to correlate with mortality after blunt chest trauma. These reports, however, predate routine truncal helical computed tomographic (CT) scanning and their conclusions are based on data derived from plain chest radiographs (CXR). CT scan provides better anatomic definition of chest injuries than plain CXR, and we hypothesized CT evaluation of rib fracture number and patterns would provide a better prediction of respiratory failure and mortality after chest injury than the data derived from the initial CXR. METHODS The charts on all patients of 16 years or older with one or more rib fractures after blunt trauma admitted from January 2003 through December 2005 were reviewed. Both the initial CXR and the helical CT scans were systematically re-read for the number and location of rib fractures and presence of pulmonary contusions. Anatomic fracture location (anterior, posterior, lateral) was determined using a standardized template. Outcomes data included pneumonia, respiratory failure (>/=3 ventilator days), need for trachestomy, and mortality. Logistic regression was performed to identify factors that predicted pulmonary morbidity. RESULTS Three hundred and eighty eight patients had >/=1 rib fracture. The mean (+/-standard deviation) age was 44 +/- 18. injury severity score was 21 +/- 11. Mortality was 6% (22 of 388). Sixty-three (16%) patients developed respiratory failure. The mean number of rib fractures per patient was four (range, 1-23); 21% of patients had one rib fracture and 17% had six or more fractures. 208 (54%) of the initial CXRs were read as having no rib fractures. The mean number of rib fractures per patient in this group was 3.1 (CI95 2.9-3.2). In 43% (179 of 388) of patients, the CT radiology report incorrectly identified the number and location of the fractured ribs. Of these reports, 72% (129 of 179) differed from the prospective review by more than one fracture. The number of fractures was higher in patients who died (7 +/- 5 vs. 4 +/- 3; p = 0.02) and in those developing respiratory failure (6 +/- 4 vs. 3 +/- 3; p = 0.02). Any rib fracture or pulmonary contusion visible on the initial plain CXR significantly increased the incidence of pulmonary morbidity or mortality. CT determination of fracture location had no effect on respiratory failure, pneumonia, or mortality when fractures were confined to one anatomic location. The presence of rib fracture in more than anatomic region doubled the incidence of respiratory failure (24% vs. 12%; p = 0.002) but had no effect on mortality. Logistic regression identified only injury severity score and presence of a parenchymal injury on plain CXR as independent predictors of subsequent respiratory failure. CONCLUSIONS Rib fracture mortality was lower than that in the previously published studies and is likely reflect the increased sensitivity of CT scan in diagnosing rib fractures. Screening CXRs miss rib fractures more than 50% of the time. Radiology reports are often not sufficiently descriptive or are incomplete with respect to the number and location fracture and reliance on these data will lead to erroneous conclusions. Using CT scanning, only the finding of rib fractures in multiple locations was associated with increased incidence of respiratory failure. In contrast, the presence of any parenchymal injury or visible rib fracture on the screening CXR significantly increases the risk for subsequent pulmonary morbidity (odds ratio, 3.8; CI95, 2.2-6.6). Although truncal CT scanning markedly improved the diagnosis and delineation of rib fractures, the screening CXR was a better predictor of subsequent pulmonary morbidity and mortality.