Incidence of healthcare-associated infections in patients with fever during the first 48 hours after decannulation from veno-venous extracorporeal membrane oxygenation.

INTRODUCTION: Fevers following decannulation from veno-venous extracorporeal membrane oxygenation often trigger an infectious workup; however, the yield of this workup is unknown. We investigated the incidence of post-veno-venous extracorporeal membrane oxygenation decannulation fever as well as the incidence and nature of healthcare-associated infections in this population within 48 hours of decannulation. METHODS: All patients treated with veno-venous extracorporeal membrane oxygenation for acute respiratory failure who survived to decannulation between August 2014 and November 2018 were retrospectively reviewed. Trauma patients and bridge to lung transplant patients were excluded. The highest temperature and maximum white blood cell count in the 24 hours preceding and the 48 hours following decannulation were obtained. All culture data obtained in the 48 hours following decannulation were reviewed. Healthcare-associated infections included blood stream infections, ventilator-associated pneumonia, and urinary tract infections. RESULTS: A total of 143 patients survived to decannulation from veno-venous extracorporeal membrane oxygenation and were included in the study. In total, 73 patients (51%) were febrile in the 48 hours following decannulation. Among this cohort, seven healthcare-associated infections were found, including five urinary tract infections, one blood stream infection, and one ventilator-associated pneumonia. In the afebrile cohort (70 patients), four healthcare-associated infections were found, including one catheter-associated urinary tract infection, two blood stream infections, and one ventilator-associated pneumonia. In all decannulated patients, the majority of healthcare-associated infections were urinary tract infections (55%). No central line-associated blood stream infections were identified in either cohort. When comparing febrile to non-febrile cohorts, there was a significant difference between pre- and post-decannulation highest temperature (p < 0.001) but not maximum white blood cell count (p = 0.66 and p = 0.714) between the two groups. Among all positive culture data, the most commonly isolated organism was Klebsiella pneumoniae (41.7%) followed by Escherichia coli (33%). Median hospital length of stay and time on extracorporeal membrane oxygenation were shorter in the afebrile group compared to the febrile group; however, this did not reach a statistical difference. CONCLUSION: Fever is common in the 48 hours following decannulation from veno-venous extracorporeal membrane oxygenation. Differentiating infection from non-infectious fever in the post-decannulation veno-venous extracorporeal membrane oxygenation population remains challenging. In our febrile post-decannulation cohort, the incidence of healthcare-associated infections was low. The majority were diagnosed with a urinary tract infection. We believe obtaining cultures in febrile patients in the immediate decannulation period from veno-venous extracorporeal membrane oxygenation has utility, and even in the absence of other clinical suspicion, should be considered. However, based on our data, a urinalysis and urine culture may be sufficient as an initial work up to identify the source of infection.

Pharmacologic Treatment Reduces Pressure Times Time Dose and Relative Duration of Intracranial Hypertension.

INTRODUCTION: Past work has shown the importance of the "pressure times time dose" (PTD) of intracranial hypertension (intracranial pressure [ICP] > 19 mm Hg) in predicting outcome after severe traumatic brain injury. We used automated data collection to measure the effect of common medications on the duration and dose of intracranial hypertension. METHODS: Patients >17 years old, admitted and requiring ICP monitoring between 2008 and 2010 at a single, large urban tertiary care facility, were retrospectively enrolled. Timing and dose of ICP-directed therapy were recorded from paper and electronic medical records. The ICP data were collected automatically at 6-second intervals and averaged over 5 minutes. The percentage of time of intracranial hypertension (PTI) and PTD (mm Hg h) were calculated. RESULTS: A total of 98 patients with 664 treatment instances were identified. Baseline PTD ranged from 27 (before administration of propofol and fentanyl) to 150 mm Hg h (before mannitol). A "small" dose of hypertonic saline (HTS; ≤250 mL 3%) reduced PTD by 38% in the first hour and 37% in the second hour and reduced the time with ICP >19 by 38% and 39% after 1 and 2 hours, respectively. A "large" dose of HTS reduced PTD by 40% in the first hour and 63% in the second (PTI reduction of 36% and 50%, respectively). An increased dose of propofol or fentanyl infusion failed to decrease PTD but reduced PTI between 14% (propofol alone) and 30% (combined increase in propofol and fentanyl, after 2 hours). Barbiturates failed to decrease PTD but decreased PTI by 30% up to 2 hours after administration. All reductions reported are significantly changed from baseline, P < .05. CONCLUSION: Baseline PTD values before drug administration reflects varied patient criticality, with much higher values seen before the use of mannitol or barbiturates. Treatment with HTS reduced PTD and PTI burden significantly more than escalation of sedation or pain management, and this effect remained significant at 2 hours after administration.

Experiences that matter in bipolar disorder: a qualitative study using the capability, comfort and calm framework.

BACKGROUND: When assessing the value of an intervention in bipolar disorder, researchers and clinicians often focus on metrics that quantify improvements to core diagnostic symptoms (e.g., mania). Providers often overlook or misunderstand the impact of treatment on life quality and function. We wanted to better characterize the shared experiences and obstacles of bipolar disorder within the United States from the patient's perspective. METHODS: We recruited 24 individuals diagnosed with bipolar disorder and six caretakers supporting someone with the condition. Participants were involved in treatment or support services for bipolar disorder in central Texas. As part of this qualitative study, participants discussed their everyday successes and obstacles related to living with bipolar disorder during personalized, open-ended interviews. Audio files were transcribed, and Nvivo software processed an initial thematic analysis. We then categorized themes into bipolar disorder-related obstacles that limit the patient's capability (i.e., function), comfort (i.e., relief from suffering) and calm (i.e., life disruption) (Liu et al., FebClin Orthop 475:315-317, 2017; Teisberg et al., MayAcad Med 95:682-685, 2020). We then discuss themes and suggest practical strategies that might improve the value of care for patients and their families. RESULTS: Issues regarding capability included the struggle to maintain identity, disruptions to meaningful employment, relationship loss and the unpredictable nature of bipolar disorder. Comfort related themes included the personal perception of diagnosis, social stigma and medication issues. Calm themes included managing dismissive doctors, finding the right psychotherapist and navigating financial burdens. CONCLUSIONS: Qualitative data from patients with bipolar disorder helps identify gaps in care or practical limitations to treatment. When we listen to these individuals, it is clear that treatments must also address the unmet psychosocial impacts of the condition to improve patient care, capability and calm.

Facing Trauma and Surgical Emergency in Space: Hemorrhagic Shock.

Although the risk of trauma in space is low, unpredictable events can occur that may require surgical treatment. Hemorrhage can be a life-threatening condition while traveling to another planet and after landing on it. These exploration missions call for a different approach than rapid return to Earth, which is the policy currently adopted on the International Space Station (ISS) in low Earth orbit (LEO). Consequences are difficult to predict, given the still scarce knowledge of human physiology in such environments. Blood loss in space can deplete the affected astronaut's physiological reserves and all stored crew supplies. In this review, we will describe different aspects of hemorrhage in space, and by comparison with terrestrial conditions, the possible solutions to be adopted, and the current state of the art.

Validity and severity thresholds for the depression subscale of the affective self rating scale: An equipercentile equating study using classical test theory.

BACKGROUND: The Affective Symptoms Scale (ASRS) is a unique instrument designed to separately measure depressive and manic symptoms in mood disorders. We validated the ASRS against the Patient Health Questionnaire (PHQ-9) and the Quick Inventory of Depressive Symptomatology (QIDS-16). METHODS: A retrospective study of 258 patients who completed the PHQ-9, QIDS-16 and ASRS as part of routine clinical care. To establish meaningful clinical thresholds for the depression subscale of the ASRS, it was equated with the QIDS and the PHQ-9. RESULTS: The depression subscale of the ASRS had significant positive correlations with the QIDS-16 and the PHQ-9 (respectively, r= 0.8, t[253] = 19.8, p < 0.001, and r= 0.8, t[245] = 28.2, p < 0.001). The equipercentile equating method with the PHQ-9 indicated that the thresholds corresponded to ASRS depression subscale scores of 5.4, 10.6, 16.1, and 23. Equating with the QIDS indicated that thresholds corresponded to ASRS depression subscale scores of 5.1, 11, 18.4, and 27.5. LIMITATIONS: Limitations include a small sample size that did not allow more detailed statistical analysis, such as Item Response Theory. The population is a heterogenous population at a university outpatient setting. CONCLUSIONS: The ASRS depression subscale significantly correlated with the PHQ-9 and QIDS-16. Our proposed threshold scores for the ASRS are 5, 11, 16 and 23 to indicated mild, moderate, severe and very severe depression respectively.

Impact of trauma centre capacity and volume on the mortality risk of incoming new admissions.

INTRODUCTION: Trauma centre capacity and surge volume may affect decisions on where to transport a critically injured patient and whether to bypass the closest facility. Our hypothesis was that overcrowding and high patient acuity would contribute to increase the mortality risk for incoming admissions. METHODS: For a 6-year period, we merged and cross-correlated our institutional trauma registry with a database on Trauma Resuscitation Unit (TRU) patient admissions, movement and discharges, with average capacity of 12 trauma bays. The outcomes of overall hospital and 24 hours mortality for new trauma admissions (NEW) were assessed by multivariate logistic regression. RESULTS: There were 42 003 (mean=7000/year) admissions having complete data sets, with 36 354 (87%) patients who were primary trauma admissions, age ≥18 and survival ≥15 min. In the logistic regression model for the entire cohort, NEW admission hospital mortality was only associated with NEW admission age and prehospital Glasgow Coma Scale (GCS) and Shock Index (SI) (all p<0.05). When TRU occupancy reached ≥16 patients, the factors associated with increased NEW admission hospital mortality were existing patients (TRU >1 hour) with SI ≥0.9, recent admissions (TRU ≤1 hour) with age ≥65, NEW admission age and prehospital GCS and SI (all p<0.05). CONCLUSION: The mortality of incoming patients is not impacted by routine trauma centre overcapacity. In conditions of severe overcrowding, the number of admitted patients with shock physiology and a recent surge of elderly/debilitated patients may influence the mortality risk of a new trauma admission.

Penetrating cardiac injury.

It is understood that penetrating cardiac trauma is a highly lethal injury and those surviving to hospital have an overall mortality approaching 80%. Reported mortality figures vary widely and are extremely dependent on mechanism of wounding, cardiac chambers involved and possibly the presence of cardiac tamponade. Despite significant advances in prehospital care, operative techniques, and intensive care management, the mortality has not changed over several decades. This article will review the anatomic regions of concern for a cardiac injury, clinical presentation, and physical findings. The need for an expeditious evaluation and modalities available including, plain radiographs, sub-xiphoid window, and echocardiography will be considered. Options for surgical exposure, technical details of repairing cardiac injuries, and special circumstances such as injury adjacent to a coronary artery and intra-cardiac shunts are discussed in detail. Outcome data and future directions in managing this challenging injury are also examined.

Molecular Adsorbent Recirculating System Support Followed by Liver Transplantation for Multiorgan Failure From Heatstroke.

BACKGROUND: Exertional heatstroke is an extremely rare cause of fulminant hepatic failure. Maximal supportive care has failed to provide adequate survival in earlier studies. This is particularly true in cases accompanied by multiorgan failure. METHODS AND MATERIALS: Our prospectively collected transplant database was retrospectively reviewed to identify patients undergoing liver transplantation for heatstroke between January 1, 2012, and December 31, 2016. We report 3 consecutive cases of male patients with fulminant hepatic failure from exertional heatstroke. RESULTS: All patients developed multiorgan failure and required intubation, vasopressor support, and renal replacement therapy. All patients were listed urgently for liver transplantation and were supported with the molecular adsorbent recirculating system while awaiting transplantation. All patients underwent liver transplantation alone and are alive and well, with recovered renal function, normal liver allograft function, and no chronic sequelae of their multiorgan failure at more than one year. CONCLUSION: Extreme heatstroke leading to whole-body organ dysfunction and fulminant liver failure is a complex entity that may benefit from therapy using the Molecular Adsorbent Recirculating System while waiting for liver transplantation as a component of a multidisciplinary, multiorgan system approach.

Multidisciplinary approach for patients with pelvic fractures and hemodynamic instability.

The hemodynamically unstable patient with a pelvic fracture presents a diagnostic and therapeutic challenge. The care of these patients requires a unique multidisciplinary approach with input and expertise from many different specialists. An understanding of pelvic anatomy and fracture patterns can help guide the diagnostic evaluation and treatment plan. The initial management of these patients must focus on rapid airway and hemorrhage control while preparing for ongoing blood loss. Rapid temporary fracture stabilization with simple bedside modalities is crucial in limiting additional blood loss. An exhaustive search must also be performed to evaluate for concomitant injuries that commonly accompany major pelvic fractures and the treatment of these other injuries must be appropriately prioritized. For patients who are unresponsive to standard resuscitation and bedside attempts at limiting hemorrhage, angiographic embolization is often utilized as the next step to attain hemodynamic stability. The key to successful management of these patients lies in the careful coordination of different specialists and the expertise that each brings to the clinical care of the patient.

2016 WSES guidelines on acute calculous cholecystitis.

Acute calculus cholecystitis is a very common disease with several area of uncertainty. The World Society of Emergency Surgery developed extensive guidelines in order to cover grey areas. The diagnostic criteria, the antimicrobial therapy, the evaluation of associated common bile duct stones, the identification of "high risk" patients, the surgical timing, the type of surgery, and the alternatives to surgery are discussed. Moreover the algorithm is proposed: as soon as diagnosis is made and after the evaluation of choledocholitiasis risk, laparoscopic cholecystectomy should be offered to all patients exception of those with high risk of morbidity or mortality. These Guidelines must be considered as an adjunctive tool for decision but they are not substitute of the clinical judgement for the individual patient.

Erratum to: 2016 WSES guidelines on acute calculous cholecystitis.

[This corrects the article DOI: 10.1186/s13017-016-0082-5.].

Loop versus end colostomy reversal: has anything changed?

PURPOSE: Though primary repair of colon injuries is preferred, certain injury patterns require colostomy creation. Colostomy reversal is associated with significant morbidity and healthcare cost. Complication rates may be influenced by technique of diversion (loop vs. end colostomy), though this remains ill-defined. We hypothesized that reversal of loop colostomies is associated with fewer complications than end colostomies. METHODS: This is a retrospective, multi-institutional study (four, level-1 trauma centers) of patients undergoing colostomy takedown for trauma during the time period 1/2006-12/2012. Data were collected from index trauma admission and subsequent admission for reversal and included demographics and complications of reversal. Student's t test was used to compare continuous variables against loop versus end colostomy. Discrete variables were compared against both groups using Chi-squared tests. RESULTS: Over the 6-year study period, 218 patients underwent colostomy takedown after trauma with a mean age of 30; 190 (87%) were male, 162 (74%) had penetrating injury as their indication for colostomy, and 98 (45%) experienced at least one complication. Patients in the end colostomy group (n = 160) were more likely to require midline laparotomy (145 vs. 18, p < 0.001), had greater intra-operative blood loss (260.7 vs. 99.4 mL, p < 0.001), had greater hospital length of stay (8.4 vs. 5.5 days, p < 0.001), and had more overall complications (81 vs. 17, p = 0.005) than patients managed with loop colostomy (n = 58). CONCLUSIONS: Local takedown of a loop colostomy is safe and leads to shorter hospital stays, less intra-operative blood loss, and fewer complications when compared to end colostomy.

Community-acquired infections in the geriatric trauma population.

The incidence of community-acquired infections (CAs) and their relationship to the incidence of nosocomial infections (NI), to our knowledge, is unknown in elderly trauma patients. We prospectively collected data on 380 patients > or =65 years of age who were admitted >48 h to our trauma center over a 2-year period. One hundred seventy-seven patients (47%) developed an infection. A total of 147 (39%) patients were diagnosed with an NI, and 67 (18%) were diagnosed with a CA. Of the 67 patients with CA, 37 (55%) went on to develop an NI. Patients with the combination of CA and NI had the greatest mean ICU (28.6 days) and hospital length of stay (38.2 days). Mortality was increased significantly in patients with the combination of CA and NI (27%). Respiratory and genitourinary infections were the most common CA. Patients with respiratory CAs accounted for the greatest proportion of NIs. Thus, community-acquired and nosocomial infections significantly increase morbidity and mortality in elderly patients post-injury. Patients who present with a CA are at increased risk of acquiring an NI, which is associated with the most significant increase in length of stay and mortality.

Outcome in post-traumatic acute renal failure when continuous renal replacement therapy is applied early vs. late.

OBJECTIVE: To determine whether the timing of initiation of continuous renal replacement therapy (CRRT) affects outcome in patients with post-traumatic acute renal failure (ARF). DESIGN: The medical records of patients treated with CRRT for post-traumatic ARF were retrospectively reviewed. Chi-square testing was used to test frequencies between groups, and Student's t -test was used to compare means. SETTING: A Level I trauma center. PATIENTS: 100 Adult trauma patients treated with CRRT for ARF from 1989 to 1997. Patients were characterized as "early" or "late" starters, based upon whether the blood urea nitrogen (BUN) was less than or greater than 60 mg/dl, prior to CRRT initiation. RESULTS: The mean BUN of the early and late starters was 42.6 and 94.5 mg/dl, respectively (p < 0.0001). CRRT was initiated earlier in the hospital course of early starters compared to late starters (hospital day 10.5 vs 19.4, p < 0.0001). Creatinine clearance prior to CRRT did not differ statistically between the two groups. No significant difference was found between early and late starters with respect to Injury Severity Score, admission Glasgow Coma Scale, presence of shock at admission, age, gender distribution, or trauma type. Admission laboratory values including BUN, serum creatinine, lactate, and bilirubin as well as fluid and blood requirements in the first 24 h were statistically the same for the two groups, suggesting a similar risk of developing renal failure. Survival rate was significantly increased among early starters compared to late starters (39.0 vs 20. 0 %, respectively, p = 0.041). CONCLUSIONS: This retrospective review indicates that an earlier initiation of CRRT, based on pre-CRRT BUN, may improve the rate of survival of trauma patients who develop ARF.

Release of vasoactive intestinal peptide during hyperdynamic sepsis in dogs.

Vasoactive intestinal peptide (VIP) is a potent vasodilator that has been reported to be a mediator of the hemodynamic changes in endotoxin-induced hypodynamic septic shock. We investigated the release of VIP in a hyperdynamic model of sepsis in awake, conscious dogs similar to that of sepsis in human beings. Sepsis was induced by intraperitoneal implantation of a fibrin clot containing live Escherichia coli (0.9 +/- 0.2 X 10(9) organisms per kilogram of body weight). All dogs developed hyperdynamic sepsis with increased cardiac output and decreased systemic vascular resistance. During the first 24 hours of sepsis, VIP was released without a concomitant decrease in blood pressure, suggesting that during septic shock it was released by a direct mechanism rather than as a result of hypotension. During peak VIP release (2 to 4 hours after induction of sepsis) no decreases in systemic vascular resistance or mean arterial pressure were observed. This suggests that mediators other than VIP may be responsible for the vasodilation observed during sepsis. The precise role of VIP during sepsis is therefore yet to be clarified.

Acute respiratory distress syndrome among trauma patients: trends in ICU mortality, risk factors, complications and resource utilization.

OBJECTIVE: To evaluate trends in mortality and related factors among trauma patients who developed acute respiratory distress syndrome (ARDS). STUDY: Observational study based on data prospectively gathered in computerized trauma registry. SETTING: Trauma intensive care unit (ICU) of 48 beds in level I trauma center. PATIENTS: All trauma patients with ARDS admitted during 1985-87 (486, group 1 [G1]) and 1993-95 (552, group 2[G2]). METHODS: ARDS was defined by American-European Consensus Conference criteria and the need for 48 h or more on mechanical ventilation with FIO2 greater than 0.50 and PEEP of more than 5 cmH2O. Demographics, severity score, injury-admission delay time, first 24-h transfusion and septic and organ system failure complications were independent variables. ICU mortality was the dependent variable. ICU length of stay (LOS) and life support techniques were considered. Respiratory and renal support strategies were different in the two time periods. RESULTS: Mortality decreased over the period (G1: 29.2% vs G2: 21.4%, p < 0.04), in patients aged both over and under 65 years. Multivariate analysis showed mortality was related to age, severity and time period (G1 1.68-fold that in G2) and that the greater G1 mortality was related to more renal failure and hematologic failure/dysfunction. ICU LOS decreased from 31.7+/-26.7 days (G1) to 27.3+/-22 days (G2) (p < 0.003). CONCLUSIONS: Mortality among trauma patients with ARDS declined over the 8 years studied and was associated with less organ failure. This reduction was probably the result of new approaches to mechanical ventilation, renal failure replacement and vasoactive drug therapy.

Thoracolumbar immobilization for trauma patients with torso gunshot wounds: is it necessary?

BACKGROUND: Previous studies have suggested that patients transported by emergency medical services (EMS) following major trauma had a longer injury-to-treatment interval and a higher mortality rate than their non-EMS-transported counterparts. HYPOTHESIS: There is little actual benefit of thoracolumbar immobilization for patients with torso gunshot wounds (GSW). DESIGN: Retrospective analysis of prospectively gathered data from the Maryland Institute for Emergency Medical Service Systems State Trauma Registry from July 1, 1995, through June 30, 1998. SETTINGS: All designated trauma centers in Maryland. PATIENTS: All patients with torso GSW. MAIN OUTCOME MEASURES: (1) A patient was considered to have benefited from immobilization if he or she had less than complete neurologic deficits in the presence of an unstable vertebral column, as shown by the need for operative stabilization of the vertebral column; (2) mortality. RESULTS: There were 1000 patients with torso GSW. Among them, 141 patients (14.1%) had vertebral column and/or spinal cord injuries. Two patients (0.2%) (95% confidence interval, -0.077% to 0.48%) required operative vertebral column stabilization, while 6 others required other spinal operations for decompression and/or foreign body removal. The presence of vertebral column injury was actually associated with lower mortality (7.1% vs 14.8%, P<.02). CONCLUSIONS: This study suggests that thoracolumbar immobilization is almost never beneficial in patients with torso GSW, and that a higher mortality rate existed among those GSW patients without vertebral column injury vs those with such injuries. The role of formal thoracolumbar immobilization for patients with torso GSW should be reexamined.

A multi-institutional study of factors associated with fetal death in injured pregnant patients.

HYPOTHESIS: Factors associated with fetal death in injured pregnant patients are related to increasing injury severity and abnormal maternal physiologic profile. DESIGN: A multi-institutional retrospective study of 13 level I and level II trauma centers from 1992 to 1996. MAIN OUTCOME MEASURE: Fetal survival. RESULTS: Of 27,715 female admissions, there were 372 injured pregnant patients (1.3%); 84% had blunt injuries and 16% had penetrating injuries. There were 14 maternal deaths (3.8%) and 35 fetal deaths (9.4%). The population suffering fetal death had higher injury severity scores (P<.001), lower Glascow Coma Scale scores (P<.001), and lower admitting maternal pH (P = .002). Most women who lost their fetus arrived in shock (P = .005) or had a fetal heart rate of less than 110 beats/min at some time during their hospitalization (P<.001). An Injury Severity Score greater than 25 was associated with a 50% incidence of fetal death. Placental abruption was the most frequent complication, occurring in 3.5% of patients and associated with 54% mortality. Cardiotrophic monitoring to detect potentially threatening fetal heart rates was performed on only 61% of pregnant women in their third trimester. Of these patients, 7 had abnormalities on cardiotrophic monitoring and underwent successful cesarean delivery. CONCLUSIONS: Fetal death was more likely with greater severity of injury. Cardiotrophic monitoring is underused in injured pregnant patients in their third trimester even after admission to major trauma centers. Increased use of cardiotrophic monitoring may decrease the mortality caused by placental abruption.

Experience with spiral computed tomography as the sole diagnostic method for traumatic aortic rupture.

BACKGROUND: Spiral computed tomographic (CT) scan is an excellent screen for aortic trauma. Traditionally, aortography is performed when injury is suspected to confirm the diagnosis. We hypothesized that it is safe and expeditious to forgo aortography when the spiral CT demonstrates aortic injury. METHODS: Retrospective review of 54 patients undergoing aortic repair from July 1994 to December 1999. Spiral CT was the initial diagnostic study in 52 patients. Pseudoaneurysm or aortic wall defect in the presence of mediastinal hematoma was considered diagnostic. Angiography, initially routine, was later performed only when requested by the surgeon, and for all "nonnegative" studies (periaortic hematoma without detectable aortic injury). RESULTS: Twenty-six patients underwent angiography before operation (group 1). Nineteen group 1 spiral CTs were unequivocally diagnostic; 7 were nonnegative and angiography was required. Twenty-eight other patients underwent repair based on spiral CT alone (group 2). There was one false-positive result in both groups. There were no unexpected operative findings. Mean time from admission to diagnosis was 5.7+/-3.4 hours for group 1 and 1.7+/-1.7 hours for group 2 (p < 0.01). CONCLUSIONS: Operating on the basis of a diagnostic spiral CT is safe and expeditious. Aortography may be reserved for those with equivocal studies.