Variability in radiation dose and image quality: A comparison across fluoroscopy-system vendors, generations of equipment and institutions.

OBJECTIVES: To evaluate differences in radiation dose and image quality across institutions, fluoroscope vendors and generations of fluoroscopes for pediatric cardiac catheterization. BACKGROUND: Increased recognition of the potentially harmful effects of ionizing radiation has spurred technological advances in fluoroscopes, as well as increased focus on optimizing fluoroscope performance. There is currently little understanding of variability in the dose-image quality relationship across institutions, fluoroscope vendor and/or generation of equipment. METHODS: We evaluated latest generation fluoroscopes from Phillips, Siemens, GE, and Toshiba, and an older generation Phillips fluoroscope (release date 2003) at three different institutions. Radiation dose was measured using an anthropomorphic dose-assessment phantom with effective dose in mSv estimated from Monte Carlo simulations. Image quality phantom images were scored on a 12-point scale by three blinded reviewers. RESULTS: Fluoroscope effective doses ranged from 0.04 to 0.14 mSv/1,000 pulses for fluoroscopy with associated composite image quality scores ranging from 8.0 ± 0.6 to 10.4 ± 1.3. For cineangiography, effective doses ranged from 0.17 to 0.57 mSv/1,000 frames with image quality scores ranging from 10.1 ± 0.3 to 11.1 ± 0.3. There was modest correlation between effective dose and image quality (r = 0.67, P = 0.006). The older generation fluoroscope delivered consistently higher doses than the newer generation systems (2.3- to 3.5-fold higher for fluoroscopy; 1.1- to 3.4-fold higher for cineangiography) without appreciable differences in image quality. CONCLUSION: Technological advances have markedly improved fluoroscope performance. Comparing latest generation systems across vendors and institutions, we found variability in the dose-IQ relationship and speculate that this reflects both equipment and institutional optimization practices.

Improving overtriage of aeromedical transport in trauma: a regional process improvement initiative.

BACKGROUND: Aeromedical transport (AMT) is an effective but costly means of rescuing critically injured patients. Although studies have shown that it improves survival to hospital discharge compared with ground transportation, an efficient threshold or universal criteria for this mode of transport remains to be established. Herein, we examined the effect of implementing a Trauma Advisory Committee (TAC) initiative focused on reducing AMT overtriage (OT) rates. METHODS: TAC outreach coordinators implemented a process improvement (PI) initiative and collected data prospectively from January 2007 to December 2011. OT was defined as patients who were airlifted from scene and later discharged from the emergency department. Serving as liaisons to surrounding counties, TAC outreach coordinators conducted quarterly PI meetings with local emergency medical service agencies. Patients were grouped into those who were airlifted from TAC counties versus counties outside TAC's jurisdiction (non-TAC). Standard statistical methods were used. RESULTS: From 2007 to 2011, 3,349 patients were airlifted from 30 counties, 1,427 (43%) from TAC counties and 1,922 (57%) from non-TAC counties. The OT rates from TAC counties declined compared with non-TAC counties each year and reached statistical significance in 2008 (17% vs. 23%, p < 0.05), 2009 (11% vs. 17%m p < 0.05), and 2011 (6% vs. 12%, p < 0.05). The reduction in OT continued over the study duration, with improvement in TAC counties compared with previous years. CONCLUSION: Implementation of a regional TAC PI initiative focused on OT issues led to a more efficient use of AMT. LEVEL OF EVIDENCE: Prognostic study, level III; therapeutic study, level IV.

Full-scale regional exercises: closing the gaps in disaster preparedness.

BACKGROUND: Man-made (9/11) and natural (Hurricane Katrina) disasters have enlightened the medical community regarding the importance of disaster preparedness. In response to Joint Commission requirements, medical centers should have established protocols in place to respond to such events. We examined a full-scale regional exercise (FSRE) to identify gaps in logistics and operations during a simulated mass casualty incident. METHODS: A multiagency, multijurisdictional, multidisciplinary exercise (FSRE) included 16 area hospitals and one American College of Surgeons-verified Level I trauma center (TC). The scenario simulated a train derailment and chemical spill 20 miles from the TC using 281 moulaged volunteers. Third-party contracted evaluators assessed each hospital in five areas: communications, command structure, decontamination, staffing, and patient tracking. Further analysis examined logistic and operational deficiencies. RESULTS: None of the 16 hospitals were compliant in all five areas. Mean hospital compliance was 1.9 (± 0.9 SD) areas. One hospital, unable to participate because of an air conditioner outage, was deemed 0% compliant. The most common deficiency was communications (15 of 16 hospitals [94%]; State Medical Asset Resource Tracking Tool system deficiencies, lack of working knowledge of Voice Interoperability Plan for Emergency Responders radio system) followed by deficient decontamination in 12 (75%). Other deficiencies included inadequate staffing based on predetermined protocols in 10 hospitals (63%), suboptimal command structure in 9 (56%), and patient tracking deficiencies in 5 (31%). An additional 11 operational and 5 logistic failures were identified. The TC showed an appropriate command structure but was deficient in four of five categories, with understaffing and a decontamination leak into the emergency department, which required diversion of 70 patients. CONCLUSION: Communication remains a significant gap in the mass casualty scenario 10 years after 9/11. Our findings demonstrate that tabletop exercises are inadequate to expose operational and logistic gaps in disaster response. FSREs should be routinely performed to adequately prepare for catastrophic events.

Mycobacterium kansasii infection in a bontebok (Damaliscus pygaragus dorcas) herd: diagnostic challenges in differentiating from the Mycobacterium tuberculosis complex.

Two adult female bontebok (Damaliscus pygarus dorcas) were euthanized because of signs of pneumonia and weakness (case 1), and a nonresponsive lameness with draining fistula (case 2). Necropsy findings were similar in both cases and consisted of disseminated granulomatous lesions in the liver, kidneys, spleen, lungs, pleural surfaces, and multiple lymph nodes. Mycobacterium kansasii was isolated from both cases after multiple attempts on a variety of samples by two laboratories. The remaining four animals in the herd were tested for antibody responses using the Chembio ElephantTB STAT-PAK, DPP VetTB kits, and multi-antigen print immunoassay (MAPIA), for immune reaction using the intradermal tuberculin test, and by tracheal wash cultures, and thoracic radiographs. Banked serum samples collected in 2005 and obtained from the original institution, revealed 1/9 (11.11%) seropositive animals using the three immunoassays. Retesting the current herd in 2008 showed 2/6 (33.33%) seropositive animals by the three tests, with MAPIA demonstrating antibody reactivity to MPB83 and MPB70 proteins. Inconsistent intradermal tuberculin test results, cross-reactivity in serologic assays designed for tuberculosis detection, difficulty in obtaining definitive identification by culture, and inability to identify a source of infection created challenges in distinguishing the atypical mycobacteriosis due to M. kansasii from the initially suspected tuberculous infection in this herd. Owing to regulatory considerations, differences in host-to-host transmission, and source of infection between Mycobacterium tuberculosis complex and nontuberculous mycobacteria, correct diagnosis is crucial for management of these diseases in wildlife species.