A comparison between digital images viewed on a Picture Archiving and Communication System diagnostic workstation and on a PC-based remote viewing system by emergency physicians

Picture Archiving and Communication Systems (PACS) make possible the viewing of radiographic images on computer workstations located where clinical care is delivered. By the nature of their work this feature is particularly useful for emergency physicians who view radiographic studies for information and use them to explain results to patients and their families. However, the high cost of PACS diagnostic workstations with fuller functionality places limits on the number of and therefore the accessibility to workstations in the emergency department. This study was undertaken to establish how well less expensive personal computer-based workstations would work to support these needs of emergency physicians. The study compared the outcome of observations by 5 emergency physicians on a series of radiographic studies containing subtle abnormalities displayed on both a PACS diagnostic workstation and on a PC-based workstation. The 73 digitized radiographic studies were randomly arranged on both types of workstation over four separate viewing sessions for each emergency physician. There was no statistical difference between a PACS diagnostic workstation and a PC-based workstation in this trial. The mean correct ratings were 59% on the PACS diagnostic workstations and 61% on the PC-based workstations. These findings also emphasize the need for prompt reporting by a radiologist.     

Estimating the relative frequency of leukodystrophies and recommendations for carrier screening in the era of next‐generation sequencing

Leukodystrophies are a heterogeneous group of heritable disorders characterized by abnormal brain white matter signal on magnetic resonance imaging (MRI) and primary involvement of the cellular components of myelin. Previous estimates suggest the incidence of leukodystrophies as a whole to be 1 in 7,000 individuals, however the frequency of specific diagnoses relative to others has not been described. Next generation sequencing approaches offer the opportunity to redefine our understanding of the relative frequency of different leukodystrophies. We assessed the relative frequency of all 30 leukodystrophies (associated with 55 genes) in more than 49,000 exomes. We identified a relatively high frequency of disorders previously thought of as very rare, including Aicardi Goutières Syndrome, TUBB4A‐related leukodystrophy, Peroxisomal biogenesis disorders, POLR3‐related Leukodystrophy, Vanishing White Matter, and Pelizaeus‐Merzbacher Disease. Despite the relative frequency of these conditions, carrier‐screening laboratories regularly test only 20 of the 55 leukodystrophy‐related genes, and do not test at all, or test only one or a few, genes for some of the higher frequency disorders. Relative frequency of leukodystrophies previously considered very rare suggests these disorders may benefit from expanded carrier screening.     

Comparison of autonomic function using Valsalva ratio and 30:15 postural ratio prior to and after haemodialysis treatment

In published studies of chronic haemodialysis patients, the frequency of autonomic dysfunction varies widely. One reason for the variation may be the time of testing with respect to time of dialysis. The current study tests the hypothesis that autonomic function — as measured by heart rate responses to the Valsalva manoeuvre (Valsalva ratio) and 30:15 electrocardiogram (ECG) R—R interval to upright posture (postural ratio) — is different when patients are above dry weight (predialysis) than when they are at or below dry weight (postdialysis). The study also reviews available literature to analyze other factors that may affect the results of autonomic testing in this population. A total of 25 chronic haemodialysis patients underwent standard Valsalva and 30:15 R—R interval postural autonomic testing prior to and after haemodialysis. In addition, pre- and postdialysis orthostatic responses were measured and compared with a control population. The 30:15 ratio increased after dialysis (p = 0.001). The Valsalva ratio did not change with dialysis. Out of 25 subjects, seven had an abnormal 30:15 ratio prior to dialysis decreasing to two out of 25 patients postdialysis (p < 0.03). Orthostatic responses predialysis did not differ from those in the control group. Review of the literature shows great variability in definition of normal Valsalva and postural (30:15 R—R interval) ratios. Diabetic patients in the current and prior studies were more likely to have abnormal responses. In conclusion, the prevalence of autonomic dysfunction in chronic dialysis patients as determined by Valsalva and 30:15 ECG postural ratios may be influenced by the following factors: when subjects are studied with respect to their dialysis treatment; the number of subjects with diabetes; and the cut-off point used to define abnormal test results. Abnormal Valsalva ratios are less frequent when measured postdialysis.     

Medical Devices Made Into Weapons by Prisoners: An Unrecognized Risk

Study objective: The alteration of a knee immobilizer into a sharp weapon by a prisoner prompted us to survey neighboring penal institutions to determine the frequency of such events. Design: We mailed a nine-item survey to all detention facilities in Tennessee, Arkansas, and Mississippi. A second survey was sent to nonresponding institutions 6 weeks after the initial mailing. Setting: The Regional Medical Center at Memphis, the designated facility for evaluation and treatment of prisoners from the county jail and state penitentiary. Participants: Survey respondents included 25 state penitentiaries, 31 county jails, 1 state minimum-security facility, 1 state maximum-security facility, 1 work-release center, 1 county detention center for drunken-driving offenders, and 1 federal penitentiary. Results: Of the 81 institutions surveyed, 77% responded to one of the two mailings. Forty percent responded in the affirmative when asked whether stolen or unauthorized medical equipment from outside their institutions had been discovered among inmates. When respondents were questioned as to whether medical equipment, prescribed or not, had been used or altered in a criminal manner, 34% responded "yes." Medications and medical appliances were listed in the responses. Conclusion: A survey of 81 local and neighboring penal institutions in a three-state area revealed that the illicit use of medicine and medical devices by prisoners is a legitimate safety concern of prison personnel and health care workers when medical care for inmates must be sought outside the security of their institutions. The modification of medical equipment into weapons by incarcerated patients, although clearly recognized as a security and safety problem by police authorities, appears to be unappreciated by health care workers providing episodic care to inmates. [Hayden JW, Laney C, Kellermann AL: Medical devices made into weapons by prisoners: An unrecognized risk. Ann Emerg Med December 1995;26:739-742.]     

Treatment of Vitamin B12 Deficiency after Gastric Surgery for Severe Obesity

Background: Vitamin B₁₂ deficiency after gastric surgery for obesity is due to a failure of separation of vitamin B₁₂ from protein foodstuffs and to a failure of absorption of crystalline vitamin B₁₂ in the presence of intrinsic factor. The purpose of this study was to determine which of four oral doses of crystalline vitamin B₁₂ was most effective in treating vitamin B₁₂ deficiency in 102 patients. Methods and Results: At time of entry into the study, the patients had a serum vitamin B₁₂ < 100 pmol L ⁻¹, were 29.9 ± 21.7 months post-op, were 37 ± 8 years old and had a body mass index of 30 ± 6 kg m⁻². Eight (8%) had had a vertical banded gastroplasty and 94 (92%) a gastric bypass. For the first 3 months all patients received 350 μg per day of crystalline vitamin B₁₂ and all increased their serum vitamin B₁₂ levels to over 100 pmol L⁻¹. The patients were then assigned to receive for a further 3 month period one of four oral doses of crystalline vitamin B₁₂-100 μg, 250 μg, 350 μg and 600 μg. Serum vitamin B₁₂ levels were greater than 150 pmol L⁻¹ after 6 months in 83.3% of patients who received 100 μg; 92.3% of patients who received 250 μg; 94.7% after 350 μg and 95.2% after 600 μg (p%0.525). Conclusion: At least 350 μg per day is the appropriate oral dose of crystalline vitamin B₁₂ after gastric surgery for obesity to correct low serum vitamin B₁₂ levels in 95% of patients.     

Marijuana use among minority youths living in public housing developments

Youths residing in public housing developments appear to be at markedly heightened risk for drug use because of their constant exposure to violence, poverty, and drug-related activity. The purpose of this study was to develop and test a model of marijuana etiology with adolescents (N=624) residing in public housing. African-American and Hispanic seventh graders completed questionnaires about their marijuana use, social influences to smoke maijuana, and sociodemographic and psychosocial characteristics. Results indicated that social influences, such as friends' marijuana use and perceived ease of availability of marijuana, significantly predicted both occasional and future use of marijuana. Individual characteristics such as antimarijuana attitudes and drug refsul skills also predicted marijuana use. The findings imply that effective prevention approaches that target urban youths residing in public housing developments should provide them with an awareness of social influences to use marijuana, correct misperceptions about the prevalence of marijuana smoking, and train adolescents in relevant psychosocial skills.