Validation of Probabilistic Linkage to Match De-identified Ambulance Records to a State Trauma Registry

Objectives: To validate the accuracy of using probabilistic linkage for matching de‐identified ambulance records to a state trauma registry. Methods: This was a retrospective cohort analysis. Three thousand nine hundred nineteen true matches between ambulance and state trauma registry data from 1998 to 2003 were identified by deterministic matching on trauma identification number and verified by human review. Two thousand thirty‐eight ambulance records from trauma patients not meeting criteria for a true match, and an identical number of trauma registry records randomly selected from the one local county served by a different EMS provider, were included as nonmatches. There were 17 variables considered for linkage, which included the following: age, gender, race, county, hospital, date, rural setting, call and arrival times, mechanism, penetrating injury, vital signs, intubation, and intoxication. Probabilistic linkage was used to link the two data sets, using seven different combinations of common variables (maximum, 17; minimum, 4). The sensitivity and specificity of identifying true matches and nonmatches (95% confidence intervals [95% CI]) were calculated for each combination of variables. Results: Using all 17 available variables, 3,766 of 3,919 true matches were appropriately linked (sensitivity, 96.1%; 95% CI = 95.4% to 96.7%), with eight mismatches (specificity, 99.6%; 95% CI = 99.2% to 99.8%). Sensitivity fell below 95% with < 15 variables; however, sensitivity was very dependent on the inclusion of variables with high discriminatory power. Specificity remained >98% regardless of the number of variables included. Conclusions: Probabilistic linkage is a valid method for matching ambulance records to a trauma registry without the use of patient identifiers; however, the sensitivity of identifying true matches is critically dependent on the number and type of common variables included in the analysis.     

Gender Trends in Emergency Medicine Publications

Background In recent years, the number of women entering the field of emergency medicine (EM) has increased.
Objectives To determine if authorship in EM publications has increased in parallel with this trend.
Methods The gender of first and last authors of EM articles in Academic Emergency Medicine , American Journal of Emergency Medicine , Annals of Emergency Medicine , and Journal of Emergency Medicine were examined. The authors reviewed articles from 1985, 1995, and 2005 for American Journal of Emergency Medicine , Annals of Emergency Medicine , and Journal of Emergency Medicine and from 1999 and 2005 for Academic Emergency Medicine . The primary outcomes were the proportions of female authors.
Results A total of 2,016 articles were reviewed. Overall, 18% of first and last authors were female. Respectively, for 1985, 1995, 1999, and 2005, the proportions of female first authors were 9%, 15%, 19%, and 24%; the proportions of female last authors were 9%, 18%, 19%, and 22%. The trend of increases in female authorship was statistically significant.
Conclusions Although female authorship remains a minority in EM publications, it has increased significantly in parallel with increases in female participation in EM.     

骨盆骨折并单纯性腹腔内出血的误诊及急救处理教训

目的总结骨盆骨折并单纯性腹腔内出血误诊经验教训及急救处理。方法对8例骨盆骨折并单纯性腹腔内出血的伤因、诊断、急救方法选择进行回顾性分析。结果骨盆骨折并单纯性腹腔内出血与伤因及搬运不当致骨折移位、再移位密切相关；与骨折部位也关系密切；骨盆骨折并单纯性腹腔内出血常易误诊为腹腔内脏合并伤而行剖腹探查术时确诊，腹膜后血肿探查止血，术中、术后死亡率高。结论骨箍骨折并单纯性腹腔内出血易误诊为腹内脏器伤，救治困难，死亡率高。     

非控制性出血休克大鼠早期低压液体复苏的理想复苏压力研究

目的利用大鼠非控制性出血休克模型,探讨早期低压复苏的理想复苏压力。方法W istar大鼠64只,基础平均动脉血压(MAP)为(129.9±14.3)mmHg,断脾法复制非控制性出血休克模型,将血压(MAP)降至40或50mmHg,分为3个处理时段,第1时段模拟院前救治时段,用2∶1乳酸林格氏液和6%的右旋糖酐输注分别将MAP维持在40、50、60、70、80、100mmHg,维持1小时;第2时段模拟医院确定性处理情况,结扎脾动脉止血,输血输液将MAP恢复至100mmHg,维持2小时;第3时段,观察第1时段不同压力复苏对大鼠休克复苏效果的影响。观察指标包括动物存活情况、血压、液体输注量、血细胞比容及动脉血气等。结果院前急救采用高压复苏(80、100mmHg),动物存活时间短,在第1时段末就有50%的动物死亡,需要的液体输注量大,血液稀释严重,代谢性酸中毒明显,血气指标差;而以<70mmHg(50、60、70mmHg)的血压复苏,动物存活时间延长,液体输注量小,血液稀释轻,血气指标正常或接近正常;以50、60mmHg血压输注效果最好,但太低的输注压力(40mmHg)也不利于休克复苏,在第三时段末动物死亡率为75%。结论对非控制性出血休克及活动性出血,止血前采用高压复苏会增加血液丢失及血液稀释,明显影响休克复苏效果,适当低压复苏有利于动物的后期恢复,输注压力以50、60mmHg最好,但太低的输注压力(40mmHg)也不利于休克复苏。     

A comprehensive strategy for the evaluation and triage of the chest pain patient: A cost comparison study

BACKGROUND: Our objective was to determine the cost-effectiveness of a comprehensive, risk-based triage system, composed of multiple critical pathways, with the use of early myocardial perfusion imaging (MPI) in low-risk patients. We found previously that a chest pain evaluation system that uses MPI in low-risk patients was safe and effective, but the cost-effectiveness of this approach was not studied. METHODS AND RESULTS: We compared two groups. The Acute Cardiac Team (ACT) group (n = 874) was assigned prospectively to 1 of 4 risk levels by emergency department (ED) physicians. Level 1, 2, and 3 patients were admitted; level 4 patients were evaluated in the ED. Level 3 and 4 patients underwent ED MPI. The control group (n = 713) represented consecutive patients evaluated in the prior year according to standard care and assigned retrospectively to an ACT level based on the presenting electrocardiographic and clinical data. Record and hospital administrative data were assessed for clinical variables, outcomes, lengths of stay, and all expenses incurred within 30 days of the index visit. The baseline characteristics of the two groups were similar, including age, sex, myocardial infarction prevalence, and 30-day revascularization rates within each level or between the two groups. Mean costs per encounter were reduced for the ACT patients for each level, which was significant when all patients were compared ($5,030 +/- $7,081 vs $6,044 +/- $10,432, P =.02). Use of MPI in the low-risk patients was associated with reduced costs (level 3, $4,958 +/- $4,948 vs $5,051 +/- $7,036; level 4, $1,529 +/- $2,664 vs $1,794 +/- $6,854) and was associated with a significantly lower angiography rate and shorter length of stay. CONCLUSIONS: Implementation of a comprehensive strategy for chest pain evaluation and triage reduced overall costs for patients with chest pain on presentation. Acute MPI in the ED setting did not increase net cost.     

Early Stroke Recognition: Developing an Out-of-hospital NIH Stroke Scale

Objective : To develop an abbreviated and practical neurologic scale that could assist emergency medical services or triage personnel in identifying patients with stroke.
Methods : A prospective, observational, cohort study was performed at university-based EDs. Participants were 74 patients treated in a thrombolytic stroke trial and 225 consecutive non-stroke patients evaluated during 4 random 12-hour shifts in the ED. Scores on the NIH Stroke Scale were obtained for all patients by physicians. Items of this scale were modified and recoded to a binomial (normal or abnormal) scale. Serial univariate analyses using χ² were performed to rank items. Recursive partitioning was then performed to develop the decision rule for predicting the presence of stroke.
Results : Three items identified 100% of patients with stroke: facial palsy, motor arm, and dysarthria. An Abbreviated NIH Stroke Scale based on these items had a sensitivity of 100% and a specificity of 92%. A proposed Out-of-hospital NIH Stroke Scale consisting of facial palsy, motor arm, and a combination of dysarthria and best language items (abnormal speech) had a sensitivity of 100% and a specificity of 88%.
Conclusion : Using the derivation data set, a proposed Out-of-hospital NIH Stroke Scale had a high sensitivity and specificity for identifying patients with stroke when performed by physicians in this group of 299 ED patients. Prospective studies of other health care professionals using the scale in the out-of-hospital arena are needed.     

An Approach to Emergency Department Photography

In the emergency department, photography requires an expedient, portable, adaptable, and relatively simple camera system to take advantage of fleeting opportunities for recording visually educational material. These prerequisites are different from those for traditional medical photography, for which relatively plentiful time and advanced equipment are routinely available. Medical photography departments provide an invaluable service, but are rarely convenient for immediate or spontaneous emergency. department photographs. Although no single system or technique is optimal in all these areas, the authors find certain components and approaches work well. They review photographic equipment, paying attention to speed, ease of use, and quality of output. They also review simple techniques such as film choice, lighting, close-up photography, standardization, copy work, and radiographs. Attention to these details can help the inexperienced photographer obtain a system and begin to enjoy the rewards of effective photography in the emergency department.