Response of balloon-expandable endoprosthetic metallic stents subjected to over-expansion in vitro.

We attempted to evaluate the in vitro behavior and performance of balloon-expandable endoprosthetic metallic stents subjected to over-expansion (OE). Seventy-two balloon-expandable endoprosthetic stents, representing 22 models from six manufacturers, were overexpanded in vitro. Stents were initially expanded to their maximum manufacturer- recommended diameter and then over-expanded incrementally to their endpoints. Endpoints for OE were either stent disarticulation or an inability to undergo further expansion despite balloon insufflation to maximum burst pressure. Measurements of stent dimensions were recorded at each overexpanded diameter and comparisons were made to manufacturer's specifications. A total of 288 balloon-driven expansions were performed on 72 stents. Sixteen stents were expanded to large diameters (> or = 16 mm), 20 stents underwent OE of 50% or greater. One model tended to disarticulate after OE greater than 50%. There were five models that had a tendency to disarticulate after minimal OE. Five models were resistant to OE (25% or less OE) but did not disarticulate. Nearly all stents showed some degree of foreshortening with OE, while 36 stents underwent foreshortening of 30% or more. Models that are not recommended for OE include Intrastent, Intrastent DoubleStrut, NIR Royale and Omniflex. Good candidates for OE include Intrastent DoubleStrut LD, Palmaz large, Medtronic Extra Support Biliary Plus and Medtronic Flexible Biliary. Palmaz XL remains the only model available for expansion from 20 to 28 mm in diameter. For the remaining stents, OE is possible, however, caution should be used.

Physician versus computer knowledge of potential drug interactions in the emergency department.

INTRODUCTION: Proliferation of Food and Drug Administration-approved drugs makes it impossible for emergency medicine (EM) faculty to stay current on potential interactions between drugs, and with diseases, laboratory tests, and ethanol. A computer database may augment physician knowledge. OBJECTIVES: To compare the performance of EM faculty and an "expert" emergency physician (EP) with that of a criterion standard computer database in identifying potential drug interactions, and to report the incidence of drug-ethanol and drug-laboratory test interactions. METHODS: This was a retrospective review of 276 emergency department charts for drug, ethanol, lab, and medical history. Evaluation by both EM faculty and an "expert" EP of patient history was done to identify potential interactions, and comparison with the Micromedex Drug-Reax database for potential interactions (graded minor, moderate, or major) was made. Clinical significance of potential interactions was judged by a second EM faculty member. RESULTS: Seventeen percent of the patients had potential drug-drug interactions, and 25% of these were judged to be clinically significant. Up to 52% of the patients had potential drug-ethanol interactions, while 38% of the patients could have potential drug-lab interactions. Sensitivity, specificity, and positive and negative predictive values of the EM faculty for potential drug-drug interactions compared with the computer were poor, at 14%, 58%, 6%, and 23%, respectively. The corresponding values for the "expert" EP were 25%, 86%, 26%, and 85%. The "expert" EP was statistically better than the EM faculty, but still less sensitive and predictive than the computer. CONCLUSIONS: A computer can aid the physician in avoiding potential drug interactions. Prospective validation of these findings should be done.

Quantification of procedures and resuscitations in an emergency medicine residency.

Currently, there are no data that govern the number of procedures that are necessary to promote competence during emergency medicine (EM) training. Nonetheless, the Residency Review Committee requires each program to report the average number of procedures and resuscitations performed by its residents. For 7 years, we have used a computer database to track resuscitation and procedure experience for 42 residents. We have documented resident experience both in our 36,000-visit Level I Trauma Center emergency department and during off-service rotations in our 400-bed university teaching hospital. We report data from four graduating classes (n = 24). We estimate that residents have recorded 60% of the actual procedures performed. The 24 residents documented 11,947 procedures, averaging 498 per resident (range 264-1055), and participated in 3432 resuscitations, or 143 per resident (range 64-379). Mean and standard deviations are reported for 20 specific EM procedures and 4 types of resuscitations. EM residents perform a large number of procedures, but there is wide inter-resident variability. There is no documentation that some residents perform even one of some rare but critical procedures. This tracking system suggests, then, that procedure simulations, or cadaver and animal models, must be developed and used to enhance experience. This program can be modified to track resident experience in any specialty, as well as to document supervision by faculty and support credentialling inquiries.