Effectiveness of medical resident education in mechanical ventilation

Specific methods of mechanical ventilation management reduce mortality and lower health care costs. However, in the face of a predicted deficit of intensivists, it is unclear whether residency programs are training internists to provide effective care for patients who require mechanical ventilation. To evaluate these educational outcomes, we administered a validated 19-item case-based test and survey to resident physicians at 31 diverse U.S. internal medicine residency programs nationwide. Of 347 senior residents, 259 (75%) responded. The mean test score was 74% correct (SD, 14%; range, 37 to 100%). Important items representing evidence-based standards of critical care answered incorrectly were as follows: use of appropriate tidal volume in the acute respiratory distress syndrome (48% incorrect), identifying a patient ready for a weaning trial (38% incorrect), and recognizing indication for noninvasive ventilation (27% incorrect). Most accurately identified pneumothorax (86% correct) and increased intrathoracic positive end-expiratory pressure (93% correct). Better scores were associated with "closed" versus "open" intensive care unit organization (76 versus 71% correct, p = 0.001), resident perception of greater versus lesser ventilator knowledge (79 versus 71% correct, p = 0.001), and graduation from a U.S. versus international medical school (75 versus 69% correct, p = 0.033). Although overall training satisfaction correlated strongly with program use of learning objectives (r = 0.89, p < 0.0001), only 46% reported being satisfied with their mechanical ventilation training. We conclude that senior residents may not be gaining essential evidence-based knowledge needed to provide effective care for patients who require mechanical ventilation. Residency programs should emphasize evidence-based learning objectives to guide mechanical ventilation instruction.     

Renal segmental tubular response to salt during the normal menstrual cycle

BACKGROUND: It has been suggested that women gain weight and develop peripheral edema during the luteal phase of the menstrual cycle because they tend to retain sodium and water. However, there is actually no clear evidence for physiological, cyclic variations in renal sodium handling during the menstrual cycle. We prospectively assessed the changes in segmental renal sodium handling occurring during the menstrual cycle in response to changes in salt intake. METHODS: Thirty-five normotensive women were enrolled. Seventeen women were randomized and studied in the follicular and 18 in the luteal phases of their menstrual cycle. All women were assigned at random to receive a low (40 mmol/day) or a high (250 mmol/day) sodium diet for seven days on two consecutive menstrual cycles. Renal sodium handling and hemodynamics were measured at the end of each diet period. RESULTS: The changes in sodium intake induced comparable variations in sodium excretion in both phases of the menstrual cycle. In the follicular phase, the increase in salt intake was associated with no change in renal hemodynamics, an increased fractional excretion of lithium (FELi) and a decreased fractional distal reabsorption of sodium (FDRNa), suggesting that sodium reabsorption is reduced both in the proximal and the distal tubules. In contrast, in the luteal phase, the renal response to salt was characterized by a significant renal vasodilation and a marked salt escape from the distal nephron, compared to the women investigated in the follicular phase (P < 0.01). Sodium reabsorption by the proximal nephron was not reduced as indicated by the unchanged FELi. CONCLUSIONS: These results show that the segmental renal handling of sodium differs markedly in the two phases of the menstrual cycle. They suggest that the female hormones modulate the renal handling of sodium at the proximal and distal segments of the nephron in young normotensive women.     

Using the net benefit regression framework to construct cost-effectiveness acceptability curves: an example using data from a trial of external loop recorders versus Holter monitoring for ambulatory monitoring of "community acquired" syncope

Background  

Cost-effectiveness acceptability curves (CEACs) describe the probability that a new treatment or intervention is cost-effective. The net benefit regression framework (NBRF) allows cost-effectiveness analysis to be done in a simple regression framework. The objective of the paper is to illustrate how net benefit regression can be used to construct a CEAC.     

Carbon Dioxide and Gadopentetate Dimeglumine Venography to Guide Percutaneous Vertebroplasty

Percutaneous vertebroplasty with polymethylmethacrylate (PMMA) is an effective procedure for relieving pain due to vertebral body compression fractures. The technique employs iodinated contrast venography to exclude needle placement directly within the basivertebral complex. We present two cases in which carbon dioxide (CO₂) and gadopentetate dimeglumine venography was used to guide percutaneous vertebroplasty in patients with a contraindication to iodinated contrast.     

Multiple sclerosis: Oligoclonal IgG, ξ-λ light chain distribution and measles antibodies in brain extracts

The presence of measles antibodies in white and grey brain material and in 8 demyelination plaques from 6 patients affected with multiple sclerosis was investigated with the hemagglutination inhibition (HI) and complement fixation (CF) techniques.White and grey matter of 5 controls were run in parallel. No measles antibodies could be detected, except for one plaque, where the answer could be considered as doubtful. The immunoglobulin G (IgG) content and the ξ/λ light chain ratios of all the samples were evaluated. No unique monoclonal immunoglobulin population could be detected, but ξ or λ predominant oligoclonal populations appeared in controls as well as in MS IgG.     

Dominant form of vanishing white matter-like leukoencephalopathy

Leukoencephalopathy with vanishing white matter syndrome (childhood ataxia with central nervous system hypomyelination/vanishing white matter disease) is an autosomal recessive disorder characterized by the occurrence of acute episodes of deterioration after minor head trauma or infection, and symmetrical demyelination on magnetic resonance with cavitation aspects. Mutations in each of the five subunits of eIF2B have been identified. We report in an affected man and his mother an adult-onset form of childhood ataxia with central nervous system hypomyelination/vanishing white matter disease-like disorder with no mutations in the EIF2B genes and normal guanine nucleotide exchange factor eIF2B activity, suggesting a new dominant inheritance of this syndrome that may involve other genes.