摘要:

ObjectiveThe purpose of this study was to compare the abilities of nine Abbreviated Injury Scale (AIS)– andInternational Classification of Diseases, Ninth Revision(ICD-9)–based scoring algorithms in predicting mortality.MethodsThe scores collected on 76,871 incidents consist of four AIS-based algorithms (Injury Severity Score [ISS], New Injury Severity Score, Anatomic Profile Score [APS], and maximum AIS [maxAIS]), their four ICD to AIS mapped counterparts, and the ICD-9–based ISS (ICISS). A 10-fold cross-validation was performed and area under the receiver operating characteristic curve was used to determine algorithm discrimination. Hosmer-Lemeshow statistics were computed to gauge goodness-of-fit, and model refinement measured variance of predicted probabilities.ResultsOverall, the ICISS has the best discrimination and model refinement, whereas the APS has the best Hosmer-Lemeshow performance. ICD-9 to AIS mapped scores have worse discrimination than their AIS-based counterparts, but still show moderate performance.ConclusionDifferences in performance were relatively small. Complex scores such as the ICISS and the APS provide improvement in discrimination relative to the maxAIS and the ISS. Trauma registries should move to include the ICISS and the APS. The ISS and maxAIS perform moderately well and have bedside benefits.

ISSN:0022-5282    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

BackgroundTRISS has reigned as the preeminent trauma outcome prediction model for 20 years. Despite this endorsement, the calibration of TRISS has been poor in most data sets where it has been examined. We hypothesized that the lack of calibration of TRISS was because of the inappropriate mathematical specification of the model that TRISS is based on, rather than the predictors in the model. In particular, we hypothesized that the nonlinearity of the Injury Severity Score (ISS) in the log odds of death was responsible for the poor calibration of TRISS, and further, that this nonlinearity could be corrected by the simple addition of an ISS squared term to the TRISS model.MethodsWe examined ISS in the log odds of mortality for linearity in one large trauma data set, the National Pediatric Trauma Registry (NPTR) (n = 53,113 from 1985–1996; mortality, 1.3%); and two small data sets, the University of New Mexico (UNM) (n = 3,142 from 1991–1995; mortality, 8.6%) and Portland, Oregon (PORT) (n = 2,916 from 1990–1994; mortality, 1.75%). In addition, in the NPTR we compared the calibration of TRISS models with and without linearity in the log odds of death.ResultsIn the NPTR, ISS was profoundly nonlinear in the log odds of death for both blunt and penetrating trauma (p< 0.001). Moreover, the overall calibration of the TRISS model for the NPTR data was significantly improved when the nonlinearity of ISS was corrected by the addition of a quadratic ISS term as demonstrated by a 70% reduction (improvement) in the Hosmer-Lemeshow statistic. Interestingly, the addition of the ISS squared term did not affect the discrimination of the model. The log odds of survival in the UNM and PORT data sets were also better modeled when an ISS squared term was added (UNM,p= 0 0.052; PORT,p= 0.014), but improvements in the Hosmer-Lemeshow statistic were smaller, possibly because of the small size of these data sets.ConclusionThe TRISS model for outcome prediction currently uses ISS in a mathematically inappropriate way that impairs the calibration, but not the discrimination, of its predictions. If TRISS is to continue as the prediction standard for trauma, a quadratic ISS term must be added to the model. In the future, outcome prediction models should undergo thorough statistical modeling and evaluation before being released. Injury severity descriptors other than ISS (such as ASCOT, ICISS, or NISS) may require other modeling techniques to optimize the calibration of survival models that use these injury scores.

ISSN:0022-5282    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

BackgroundLittle controversy surrounds the treatment of hemodynamically unstable patients with transmediastinal gunshot wounds (TMGSWs). These patients generally have cardiac or major vascular injuries and require immediate operation. In hemodynamically stable patients, debate surrounds the extent and order of the diagnostic evaluation. These patients can be uninjured, or can have occult vascular, esophageal, or tracheobronchial injuries. Evaluation has traditionally often included angiography, bronchoscopy, esophagoscopy, esophagography, and pericardial evaluation (i.e., pericardial window) for all hemodynamically stable patients with TMGSWs. Expansion of the use of computed tomographic (CT) scanning in penetrating injury led to a modification of our protocol. Currently, our TMGSW evaluation algorithm for stable patients consists of chest radiograph, focused abdominal sonography for trauma, and contrast-enhanced helical CT scan of the chest with directed further evaluation. The purpose of this study is to evaluate the efficiency of contrast-enhanced helical CT scan for evaluating potential mediastinal injuries and to determine whether patients can be simply observed or require further investigational studies.MethodsMedical records of hemodynamically stable patients admitted with TMGSWs over a 2-year period were reviewed for demographics, mechanism of injury, method of evaluation, operative interventions, injuries, length of stay, and complications. CT scans were considered positive if they contained a mediastinal hematoma or pneumomediastinum, or demonstrated proximity of the missile track to major mediastinal structures.ResultsTwenty-two stable patients were studied. CT scans were positive in seven patients. Directed further diagnostic evaluation in those seven patients revealed two patients who required operative intervention. Sixty-eight percent of patients had negative CT scans and were observed in a monitored setting without further evaluation. There were no missed injuries. The hospital charges generated with the CT scan-based protocol are significantly less than with the standard evaluation.ConclusionContrast-enhanced helical CT scanning is a safe, efficient, and cost-effective diagnostic tool for evaluating hemodynamically stable patients with mediastinal gunshot wounds. Positive CT scan results direct the further evaluation of potentially injured structures. Patients with negative results can safely be observed in a monitored setting without further evaluation.

ISSN:0022-5282    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

BackgroundContinuous arteriovenous rewarming (CAVR) has been shown to effectively reverse hypothermia; however, its use is limited in the setting of profound hypotension. We have evaluated the effectiveness of high-flow venovenous rewarming (HFVR) using bypass for the correction of hypothermia in a hypotensive canine model and compared these results to CAVR.MethodsEight dogs, randomly assigned to either HFVR or CAVR, were cooled to a core temperature of 29.5°C and then bled to a mean arterial pressure of 55 mm Hg. Rewarming was then initiated and the time required for blood, liver parenchyma, and esophageal (core) temperature to reach 36°C was recorded.ResultsMean flow rates were 1,536 ± 667 mL/min for HFVR and 196 ± 35 mL/min for CAVR (p= 0.007). Time in minutes to rewarm to 36°C for the HFVR versus the CAVR groups, respectively, were as follows: blood, 12 ± 2 versus 99 ± 19; liver, 21 ± 3 versus 102 ± 16; and esophageal, 25 ± 6 versus 125 ± 17 (allp< 0.001).ConclusionHFVR is an effective method for rapid rewarming in a profoundly hypothermic, hypotensive animal model and may have clinical utility in patients presenting with hypovolemia/hypotension complicated by hypothermia.

ISSN:0022-5282    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

BackgroundMild hypothermia has been proposed as a means of providing cerebral protection after traumatic brain injury. However, hypothermia has been shown to alter not only physiologic but also pharmacologic responses. The purpose of this study was to investigate whether mild hypothermia (3–4°C temperature reduction) could alter cerebral vasodilation induced by inodilators, which are characterized by having an inotropic effect in addition to a vasodilatory effect. Isoproterenol (a beta-adrenergic receptor agonist), colforsin dapropate (an adenylate cyclase stimulant), and amrinone (a phosphodiesterase inhibitor) were chosen as inodilators.MethodsThe cranial window technique, combined with microscopic video recording, was used. Forty-eight cats were randomly assigned to either a normothermic or a hypothermic group (33°C). Isoproterenol, colforsin dapropate, or amrinone was topically applied in the cranial window and the diameter of pial arterioles was measured.ResultsTopical administration of isoproterenol, colforsin dapropate, and amrinone produced a significant dilation in a dose-dependent manner during normothermia. The vasodilation induced by these inodilators was not affected by mild hypothermia.ConclusionThe vasodilation induced by topical administration of isoproterenol, colforsin dapropate, and amrinone was not affected by mild hypothermia.

ISSN:0022-5282    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

BackgroundExtracorporeal blood perfusion of the gut or enterectomy can improve survival during hemorrhagic shock (HS), suggesting that the gut may be of primary importance in resuscitation. We hypothesized that cooling the gut alone could improve survival in a rat HS model and avoid potential deleterious effects of systemic hypothermia.MethodsThirty-two Sprague-Dawley rats were anesthetized with halothane. The gut (small intestine, cecum, and colon) was exteriorized. The right atrial (TRA), rectal, and gut (TGut) intraluminal temperatures were monitored. HS was induced by withdrawal of 2 mL of blood per 100 g body weight over 10 minutes. Mean arterial pressure was then maintained at 35 to 40 mm Hg to HS 90 min. From HS 20 min to resuscitation time 1 h, rats were randomized into four groups (n = 8 each): normothermia (TRAand TGut∼38.0°C), gut-25°C (TRA∼38°C, TGut∼25°C, induced by rinsing the gut with cooled saline), gut-33°C (TRA∼38°C, TGut∼33°C), and systemic hypothermia (TRA∼33°C, TGut∼25°C). At HS 90 min, shed blood and Ringer’s solution were infused to restore normotension. Survival, metabolism, and tissue damage were observed to 72 hours.ResultsBlood pressure was not different between groups. Compared with the normothermia group, the systemic hypothermia group had lower base deficit and lactate, and needed less fluid during resuscitation for normotension (p< 0.05), but these values were not different in the gut hypothermia groups. In addition, there were no significant improvements in tissue protection induced by regional gut hypothermia, whereas the systemic hypothermia group had lower plasma potassium, lower ornithine carbamoyltransferase (marker of liver injury), and higher glucose levels after HS (allp< 0.05). All rats in the systemic hypothermia group survived to 72 hours, whereas there was only one survivor in the normothermia group, two in the gut-33°C group, and none in the gut-25°C group (allp< 0.05 vs. systemic hypothermia).ConclusionCooling the gut alone does not improve acute survival from HS, suggesting that early deaths are not secondary to gut ischemia. Mild systemic hypothermia allowed 100% survival from prolonged HS.

ISSN:0022-5282    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

BackgroundOur hypothesis was that abdominal and pelvic computed tomographic (AP-CT) scans are equivalent to portable two-view plain films in detecting lumbar spine fractures in adults. Since many trauma patients often undergo AP-CT scanning to evaluate for possible intra-abdominal injuries, using the AP-CT scan to screen for lumbar fractures could make the trauma evaluation process more efficient.MethodsThe institutional trauma registry at a Level I trauma center was used to identify all blunt lumbar fractures during a 6-year period. Medical records were reviewed.ResultsA total of 7,216 adult blunt trauma patients were evaluated, and 115 patients were identified as having a lumbar fracture, for an incidence rate of 1.6%. Missed fracture rates were high for both AP-CT scans (23.2%, 13 of 56) and portable two-view films (12.7%, 14 of 110,p= 0.08). Fifty-two patients had both AP-CT scans and plain films. In this group, AP-CT scans missed 23.1% (12 of 52) of the lumbar fractures and plain films missed 15.4% (8 of 52). However, the combination of the two diagnostic methods did not miss any fractures (0 of 52). The missed fractures required surgery or brace in 50% (7 of 14) patients who had fractures missed by plain films and 46% (6 of 13) patients whose fractures were missed by AP-CT scanning.ConclusionBoth AP-CT scans and plain films failed to diagnose significant lumbar fractures that required therapy. When screening for lumbar fractures, obtaining both AP-CT scans and portable two-view plain films may decrease missed lumbar fractures in blunt adult trauma.

ISSN:0022-5282    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

BackgroundWe have evaluated our recent experience as a Level I trauma center to test the hypothesis that preinjury anticoagulation adversely affects the morbidity and mortality of trauma patients with an intracranial injury.MethodsRecords of 380 patients admitted to the trauma service from January 1997 to December 1998 who at the time of admission were taking warfarin, low-molecular-weight heparin, aspirin, nonsteroidal anti-inflammatory drugs, clopidogrel, dipyridamole, pentoxifylline, or naproxen were reviewed. Thirty-seven patients with intracranial injuries were identified and compared with a matched (age, gender, mechanism, and severity of injury) control group of 37 patients with similar head injury but not taking any anticoagulant randomly selected from the trauma registry for that same time period.ResultsThe control and anticoagulated groups were comparable in terms of age, 75 ± 8 versus 74 ± 11 years (p= 0.655); gender, 22 men/15 women versus 21 men/16 women; mechanism of injury, 30 falls/7 motor vehicle crashes versus 30 falls/7 motor vehicle crashes; and length of hospital stay, 11 ± 14 versus 10 ± 11 days (p= 0.853). In the anticoagulated group, the mean Injury Severity Score was 17.0 ± 7.8 and the mean Glasgow Coma Scale score was 11.8 ± 4.0; these were not significantly different from the control group, which had a mean Injury Severity Score of 19.8 ± 8.1 (p= 0.143) and a Glasgow Coma Scale score of 12.5 ± 2.6 (p= 0.378). There were 14 deaths (38%) in the anticoagulation group, versus 3 deaths in the control group (8%) (p= 0.006). In the anticoagulation group, 4 of 12 patients (33%) taking warfarin died, whereas 9 of 19 patients (47%) taking aspirin died (p= 0.285). All deaths were secondary to head injuries; all deaths in the control group and all but one in the anticoagulated group were the result of a fall; 6 of 10 anticoagulated patients who fell on stairs died, and 5 of these were taking aspirin only.ConclusionThese data indicate that the trauma patient with preinjury anticoagulation such as warfarin or even aspirin who has an intracranial injury has a four- to fivefold higher risk of death than the nonanticoagulated patient. The efficacy of reversing the anticoagulant effect at the time of hospital admission remains to be evaluated.

ISSN:0022-5282    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

BackgroundAntibiotic prophylaxis, along with surgical intervention, is a key component in reducing infection in patients after penetrating abdominal trauma (PAT). Recent guidelines from the Eastern Association for the Surgery of Trauma (EAST) recommend that prophylaxis for ≤ 24 hours is adequate for most patients. We compared antibiotic prophylaxis practices after PAT at our institution with EAST guidelines, quantified the incidence of infection, and identified risk factors for infection.MethodsThis study was a retrospective review of patients with PAT requiring a therapeutic laparotomy between July 1998 and January 2001.ResultsAntibiotic prophylaxis met EAST guidelines criteria in 21 of 97 patients (22%). There was a trend toward higher infection rates (18 of 76 vs. 3 of 21;p= 0.273) when prophylaxis exceeded EAST recommendations. Multivariate analysis revealed blood transfusions to be the only predictor of infection (odds ratio, 6.9; 95% confidence interval, 2.42–19.95).ConclusionDespite prophylactic antibiotic use often exceeding EAST criteria, many patients still developed infection. Blood transfusion was the only significant risk factor for infection.

ISSN:0022-5282    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

BackgroundEfficacy of circulation depends on interactions between the heart and the vascular system. Ventricular-arterial coupling (VAC) has been described as an important determinant of cardiovascular function during resuscitation from shock. However, no prospective studies examining VAC and systemic perfusion have been performed. VAC is measured by the ratio of afterload (aortic input impedance [Ea]) to contractility (end-systolic elastance [Ees]). Lowering Ea/Eesis associated with better VAC and improved myocardial work efficiency. Our hypothesis was that optimizing VAC during resuscitation results in improved myocardial work efficiency while simultaneously improving systemic perfusion.MethodsThis was a prospective study in a consecutive series of critically injured patients. Hemodynamic variables, including Ea, Ees, and myocardial work efficiency were evaluated by constructing ventricular pressure-volume loops at the bedside during resuscitation. After pulmonary artery catheterization and adequate fluid resuscitation, left ventricular power output and Ea/Eeswere optimized with inotropic agents and/or afterload reduction. Efficiency was calculated as stroke work/total left ventricular energy expenditure. Tissue perfusion was estimated by calculating base deficit clearance per hour.ResultsTwenty-three patients were studied over a 9-month period. Fifteen patients required inotropic support or afterload reduction. Improvements were seen in Ea/Ees(from 1.0 ± 0.4 to 0.6 ± 0.2 mm Hg/mL/m2,p= 0.0004), and left ventricular power output (from 280 ± 77 to 350 ± 81 L/min/m2· mm Hg,p= 0.003) with resuscitation. A concomitant improvement in myocardial efficiency (from 70% ± 8.0% to 77% ± 5.0%,p= 0.0001) and base deficit clearance (from 0.1 ± 0.4 to −0.2 ± 0.1 mEq/L/h,p= 0.006) was seen.ConclusionImproved ventricular-arterial coupling during resuscitation is associated with improved myocardial efficiency and systemic tissue perfusion. Perfusion can be improved at lower energy cost to the heart by focusing on thermodynamic principles during resuscitation.

ISSN:0022-5282    

出版商:OVID    

年代:2002

数据来源: OVID