Mass casualty disasters: who should run the show?

BACKGROUND: A clear command structure ensures quality patient care despite overwhelmed resources during a mass casualty incident (MCI). The American College of Surgeons has stated that surgeons should strive to occupy these leadership roles. OBJECTIVE: We sought to identify whether surgeons, as compared to emergency physicians, are sufficiently prepared to assume command in the event of a mass disaster. METHODS: We surveyed hospital-affiliated surgeons and emergency physicians to assess their knowledge of MCI response principles and to gauge opinions regarding who should be in charge during a disaster. RESULTS: One hundred and forty-nine (58%) surveys were completed, 78 by surgeons and 71 by emergency physicians. Both groups demonstrated a critical lack of knowledge regarding fundamental principles and key logistical components of preparedness and MCI response. Surgeons as a group were even less prepared than emergency physicians. Of those surgeons who had reviewed their hospital's disaster plan, half (50%) still did not know where to report for an MCI activation. Nonetheless, both groups believed they had sufficient training and both asserted they ought to occupy command positions during a disaster scenario. CONCLUSIONS: Errors in disaster triage have been known to increase mortality as well as the monetary cost of disaster response. Funding exists to improve hospital preparedness, but surgeons are lagging behind emergency physicians in taking advantage of these opportunities. Overall, it is imperative that physicians improve their understanding of the MCI response protocols they will be tasked to implement should disaster strike.

Practice patterns and outcomes of retrievable vena cava filters in trauma patients: an AAST multicenter study.

BACKGROUND: The purpose of this study is to describe practice patterns and outcomes of posttraumatic retrievable inferior vena caval filters (R-IVCF). METHODS: A retrospective review of R-IVCFs placed during 2004 at 21 participating centers with follow up to July 1, 2005 was performed. Primary outcomes included major complications (migration, pulmonary embolism [PE], and symptomatic caval occlusion) and reasons for failure to retrieve. RESULTS: Of 446 patients (69% male, 92% blunt trauma) receiving R-IVCFs, 76% for prophylactic indications and 79% were placed by interventional radiology. Excluding 33 deaths, 152 were Gunter-Tulip (G-T), 224 Recovery (R), and 37 Optease (Opt). Placement occurred 6 +/- 8 days after admission and retrieval at 50 +/- 61 days. Follow up after discharge (5.7 +/- 4.3 months) was reported in 51%. Only 22% of R-IVCFs were retrieved. Of 115 patients in whom retrieval was attempted, retrieval failed as a result of technical issues in 15 patients (10% of G-T, 14% of R, 27% of Opt) and because of significant residual thrombus within the filter in 10 patients (6% of G-T, 4% of R, 46% Opt). The primary reason R-IVCFs were not removed was because of loss to follow up (31%), which was sixfold higher (6% to 44%, p = 0.001) when the service placing the R-IVCF was not directly responsible for follow up. Complications did not correlate with mechanism, injury severity, service placing the R-IVCF, trauma volume, use of anticoagulation, age, or sex. Three cases of migration were recorded (all among R, 1.3%), two breakthrough PE (G-T 0.6% and R 0.4%) and six symptomatic caval occlusions (G-T 0, R 1%, Opt 11%) (p < 0.05 Opt versus both G-T and R). CONCLUSION: Most R-IVCFs are not retrieved. The service placing the R-IVCF should be responsible for follow up. The Optease was associated with the greatest incidence of residual thrombus and symptomatic caval occlusion. The practice patterns of R-IVCF placement and retrieval should be re-examined.

Saving time, improving satisfaction: the impact of a digital radiology system on physician workflow and system efficiency.

The objective of the study was to assess UC Davis Health System's transition to digital radiology. The study involved pre- and post-PACS analyses of workflow and costs, physician satisfaction surveys, and self-recorded radiology interactions by on-call residents. The study revealed significant results. Before the PACS implementation, physicians spent one to three hours searching for films daily and were dissatisfied with radiology services. After implementation, images were readily available, physicians were more likely to view and interpret images themselves, and they reported increased satisfaction. From real-time reporting, residents viewed studies with radiologists 90.2 percent less often. Average image search time decreased, from 16 to 2 minutes, saving 21.5 physician years, worth dollar 1,034,150 annually. Reductions in film printing (73.4 percent) and file clerk full-time equivalents (50.3 percent) saved dollar 1,001,452 annually, and freed up 1,218 hospital and 8,108 warehouse square feet, worth dollar 2,018,320. As a result, UCDHS's digital radiology system improved clinician satisfaction and workflow, increased clinician image viewing, and decreased clinician engagement with radiologists. System implementation saved 21 physician years and dollar 2 million annually.

Are surgical residents prepared for mass casualty incidents?

OBJECTIVE: We hypothesized that resident education is inadequate with respect to management of mass casualty incidents that may involve chemical, biological, and nuclear exposures. METHODS: Chief level residents in surgery (n = 10), emergency medicine (n = 10), and anesthesia (n = 8) were asked to complete a survey questionnaire. Responses were tabulated and statistically analyzed with Mann-Whitney Rank Sum, Student's t test, and Kruskal-Wallis one-way analysis of variance. RESULTS: All of the residents were similar with respect to age, sex, and intended setting of clinical practice. Only a single resident reported military experience. Two residents (7.1%) had administered medical care while wearing a protective suit. Compared with emergency medicine residents, surgical residents reported significantly less formal teaching in mass casual incidents (P = 0.02), trauma triage (P = 0.01), and nuclear, biological, chemical agents (P = 0.002). When surgical residents were compared with anesthesia residents, there was significantly less training for surgical residents in nuclear, chemical, and biological agents (P = 0.02). Multiple/mass casualty incident experience did not differ between residents. However, the most common incident involved only three to five patients with blunt trauma. Emergency medicine residents were significantly more comfortable in treating patients with exposure to anthrax (P = 0.01), sarin (P = 0.04), and nuclear exposure (P = 0.01). CONCLUSIONS: Surgical residents have significantly less formal training in mass casualties, triage, and chemical, biological, and nuclear exposures than residents in other specialties. Therefore, surgical residents are less comfortable treating these types of patients. Because surgeons often are expected to take leadership roles in mass casualty incidents, surgical education should be modified to match or exceed that of other specialties.

Do all patients with left costal margin injuries require radiographic evaluation for intraabdominal injury?

STUDY OBJECTIVE: We determine whether all patients with pain or tenderness to the left lower ribs after blunt traumatic injury require abdominal computed tomography (CT) scanning for the detection of splenic injury. METHODS: This was a prospective, observational cohort of all blunt-trauma patients who had pain or tenderness to the left lower ribs and presented to the emergency department (ED) of a Level I trauma center. Patients were enrolled if they had a Glasgow Coma Scale (GCS) score greater than 13 and pain or tenderness to the left lower ribs (ribs 7 to 12). Patients with pain or tenderness to the left lower ribs were considered to have pleuritic pain if the pain increased with inspiration or cough. All hemodynamically stable patients underwent abdominal CT scanning for detection of intraabdominal injuries. Data forms collecting information on the medical history and physical examination of all patients were completed before radiographic imaging. Patients with left lower rib pain or tenderness were considered to have "isolated" left lower rib injury if they were without all of the following: ED or out-of-hospital systolic blood pressure less than 90 mm Hg, abdominal or flank tenderness, pelvic or femur fractures, and gross hematuria. RESULTS: Eight hundred seventy-five patients had left lower rib pain or tenderness, 63 (7.2%; 95% confidence interval [CI] 5.6% to 9.1%) patients had splenic injuries, and 20 (2.3%; 95% CI 1.4% to 3.5%) patients had left renal injuries. Five hundred seventy-four patients had additional indications for abdominal imaging, leaving 301 patients with "isolated" left lower rib injury. Of the 301 patients, 9 (3.0%; 95% CI 1.4% to 5.6%) had splenic injuries. All 9 patients had a pleuritic component to their rib tenderness, and 3 (33%) patients underwent splenectomy. CONCLUSION: A small but important percentage of patients with pain or tenderness to the left lower ribs has splenic injuries. All patients with splenic injury had pleuritic pain.

Comparison of six D-dimer methods in patients suspected of deep vein thrombosis.

We evaluated six D-dimer methods to determine their sensitivity, specificity, and negative predictive values (NPV) in symptomatic patients suspected of deep vein thrombosis (DVT). In patients suspected of DVT a whole blood D-dimer test (SimpliRED, Agen) was performed, and then tested using enzyme-linked immunosorbent assay (VIDAS D-Dimer, BioMerieux; Asserachrome D-Di, Stago International; Dimertest Gold, Agen) and automated immunoturbidometric methods (Advanced D-Dimer, Dade Behring; MiniQuant, Biopool). Each D-dimer method was independently compared with radiographic results to determine sensitivity and NPV. There were 151 patients enrolled in the study. Thirty-five (23.2%) patients had a positive Doppler ultrasound, with 26 proximal, eight distal, and one patient with both proximal and distal thrombus. Two patients (1.3%) had inconclusive studies and were excluded from the analyses. For all patients, the sensitivities for the rapid D-dimer methods were: SimpliRED, 82.3% [95% confidence interval (CI), 80.3-84.3%]; VIDAS D-Dimer, 91.4% (95% CI, 89.9-92.9%); MiniQuant D-Dimer, 96.3% (95% CI, 95.1-97.5%); and Advanced D-Dimer, 97.1% (95% CI, 96.3-97.9%). The sensitivity improved for SimpliRED (86.4%; 95% CI, 83.3-89.4%), VIDAS D-Dimer (95.5%; 95% CI, 85.0-100%), MiniQuant D-Dimer (100%; 95% CI, 96.9-100%) and Advanced D-Dimer (100%; 95% CI, 98.9-100%) in the inpatient population. The automated immunoturbidometric methods, the MiniQuant D-Dimer and Advanced D-Dimer, demonstrated comparable sensitivities and NPV with the VIDAS D-Dimer method in symptomatic patients suspected of DVT, which would suggest that these newer D-dimer methods could be used as part of the diagnostic algorithm for patients suspected of DVT.

Selecting the right ultrasound equipment--an administrator's perspective.

Recent advancements in ultrasound equipment, technology and capability make the selection of new or replacement equipment a difficult task. It is not uncommon that the sonographers will have different needs and wants from the equipment than do the radiologists. This potential hurdle needs to be addressed in order to arrive at a mutually acceptable selection. Vendors across the board all have very competitive products and they each have that special little "function" or "enhancement" that sets them apart from their competitor. The customer needs to approach the evaluation of the equipment in a very objective manner in order to truly understand not only the differences of each piece of equipment but the actual capability of each piece of equipment. In the end however, it is the individual sonographer that will be utilizing the equipment most of the time and they should have the final say to department management as to which equipment is selected.

Diagnosis of posttraumatic pulmonary embolism: is chest computed tomographic angiography acceptable?

BACKGROUND: Pulmonary angiography (PA-gram) has long been the accepted criterion standard for diagnosing pulmonary embolism (PE). Computed tomographic angiography has recently been advocated as an equivalent alternative to PA-gram. CT angiography is known to be insensitive for peripheral (segmental and subsegmental) emboli. We have previously found that a significant number of posttraumatic PEs occur early. We therefore hypothesized that because of the fragmentation of these early (soft) clots, posttraumatic PEs would be found disproportionately in the lung periphery. METHODS: Trauma patients with PE confirmed by PA-gram were identified from our trauma database and medical records. PA-grams and reports were re-reviewed and the location of all emboli was documented. RESULTS: We identified 45 patients, with an average age of 46 +/- 19 years; two thirds of the patients were men and 82% had a blunt mechanism of injury. Patients had PE diagnosed between days 0 and 57. Overall, PE was confined to segmental or smaller vessels in 27 (60%) patients and to subsegmental vessels in 7 (16%) patients. Twelve patients (27%) had a PE within the first 4 days. Furthermore, 32 patients (71%) had unilateral clot and 22 patients (48.9%) had clot confined to one region. CONCLUSION: PE frequently occurs soon after injury. The majority of PEs after trauma are found peripherally (in segmental or subsegmental vessels). Right/left pulmonary artery embolisms are likely to be found only later in a trauma patient's course. Any diagnostic study used to diagnose pulmonary embolism in trauma patients must have sufficient resolution capacity to reliably detect segmental and subsegmental clot. A diagnostic modality such as CT scanning that is insensitive to peripheral embolisms may miss a significant number of posttraumatic PEs.

Immune responses to the major capsid protein during parvovirus infection of rats.

Rat virus (RV) is a common parvovirus of laboratory rodents which can disrupt rat-based research. Prenatal or perinatal infection can be pathogenic or lead to persistent infection, whereas infection of adult rats is typically self-limiting. Effects on the host immune system have been documented during RV infection, but little is known about immune responses necessary for viral clearance. Our studies were conducted to identify humoral and cellular responses to the predominant capsid protein, VP2, during experimental infection of adult rats. We observed VP2-specific proliferation, gamma interferon production, and an immunoglobulin G2a humoral response that is maintained for at least 35 days following RV infection. These results strongly suggest the induction of virus-specific Th1-mediated immunity.