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Biomedical subjects

R C Wuerz

Publications and source records attributed to R C Wuerz.

At least 19 recordsLinked to original sources

Demonstration of high-fidelity simulation team training for emergency medicine.

Emergency medicine (EM) presents many cognitive, social, and systems challenges to practitioners. Coordination and communication under stress between and among individuals and teams representing a number of disciplines are critical for optimal care of the patient. The specialty is characterized by uncertainty, complexity, rapidly shifting priorities, a dependence on teamwork, and elements common to other risky domains such as perioperative medicine and aviation. High-fidelity simulators have had a long tradition in aviation, and in the past few years have begun to have a significant impact in anesthesiology. A national, multicenter research program to document the costs of teamwork failures in EM and provide a remedy in the form of an Emergency Team Coordination Course has developed to the point that high-fidelity medical simulators will be added to the hands-on training portion of the course. This paper describes an evolving collaborative effort by members of the Center for Medical Simulation, the Harvard Emergency Medicine Division, and the MedTeams program to design, demonstrate, and refine a high-fidelity EM simulation course to improve EM clinician performance, increase patient safety, and decrease liability. The main objectives of the paper are: 1) to present detailed specifications of tools and techniques for high-fidelity medical simulation; 2) to share the results of a proof-of-concept EM simulation workshop introducing multiple mannequin/ three-patient scenarios; and 3) to focus on teamwork applications. The authors hope to engage the EM community in a wide-ranging discussion and handson exploration of these methods.

Clinical Competence

Role of pilot instrument proficiency in the safety of helicopter emergency medical services.

OBJECTIVES: To determine whether instrument-proficient pilots would more safely manage a flight into unplanned instrument meteorologic conditions (IMC) than would nonproficient pilots. METHODS: A controlled experimental study was performed using a full-motion helicopter simulator. Participants were emergency medical services (EMS) pilots with commercial licenses and previous simulator experience who were blinded to the study design and hypothesis. During a simulated EMS mission, cloud ceiling and visibility were decreased until IMC prevailed, and pilot actions were recorded. Data included the altitude at which the aircraft entered IMC, and whether the pilots maintained control of the aircraft, flew within aviation standards (i.e., bank angle, airspeed), and safely landed. RESULTS: Twenty-eight pilots (13 instrument-proficient, 15 nonproficient) participated; they had a median of 6,300 hours of helicopter experience. Two pilots crashed, both from the nonproficient group. The instrument-proficient pilots lost control less often (15% vs 67%, p < 0.05), maintained instrument standards more often (77% vs 40%, p < 0.05), and entered IMC at a higher altitude (689 feet vs 517 feet, p < 0.05) compared with the nonproficient pilots. Instructor comments indicated that the nonproficient pilots made more errors than did the instrument-proficient pilots. CONCLUSIONS: Instrument-proficient pilots more safely manage an unexpected encounter with IMC. Helicopter EMS programs should strongly consider maintaining instrument proficiency to enhance safety.

Accidents, Aviation

Case management by physician assistants and primary care physicians vs emergency physicians.

OBJECTIVES: To determine whether physician assistants' (PAs') and primary care physicians' (PCPs') case management for 5 common primary care medical problems is similar to that of emergency physicians (EPs). METHODS: An anonymous survey was used to compare PAs, PCPs, and EPs regarding intended diagnostic and treatment options for hypothetical cases of asthma, pharyngitis, cystitis, back strain, and febrile child. Published national practice guidelines were used as a comparison criterion standard where available. The participants stated that they treated all of the patients and responded to all of the cases to be included in the survey. The responses of the PA and PCP groups were compared with those of the EP group, and financial charges for care by each group were analyzed. RESULTS: The EPs tended to follow treatment guidelines closer than did other primary care specialists. The management of PCPs and PAs differed from that of EPs, as follows: [table: see text] CONCLUSION: The EPs more closely followed clinical guidelines than did the PAs and PCPs for these standardized clinical scenarios. Although the relationship of such theoretical practice to actual practice remains unknown, use of these clinical scenarios may identify intended practice patterns warranting attention.

Adult

Workforce projections for emergency medicine: how many emergency physicians does the United States need?

OBJECTIVE: To mathematically model the supply of and demand for emergency physicians (EPs) under different workforce conditions. METHODS: A computer spreadsheet model was used to project annual EP workforce supply and demand through the year 2035. The mathematical equations used were: supply = number of EPs at the beginning of the year plus annual residency graduates minus annual attrition; demand = 5 full-time equivalent positions/ED x the number of hospital EDs. The demand was empirically varied to account for ED census variation, administrative and teaching responsibilities, and the availability of physician extenders. A variety of possible scenarios were tested. These projections make the assumption that emergency medicine (EM) residency graduates will preferentially fill clinical positions currently filled by EPs without EM board certification. RESULTS: Under most of the scenarios tested, there will be a large deficit of EM board-certified EPs well into the next century. Even in scenarios involving a decreasing "demand" for EPs (e.g., in the setting of hospital closures or the training of physician extenders), a significant deficit will remain for at least several decades. CONCLUSIONS: The number of EM residency positions should not be decreased during any restructuring of the U.S. health care system. EM is likely to remain a specialty in which the supply of board-certified EPs will not meet the demand, even at present levels of EM residency output, for the next several decades.

Computer Simulation

Analysis of factors affecting U.S. emergency physician workforce projections. SAEM Workforce Task Force.

OBJECTIVES: To use existing data sources to refine prior estimates of the U.S. emergency medicine (EM) workforce and to estimate effects of proposed changes in the U.S. health care system on the EM workforce. METHODS: Relevant data were extracted from the American College of Emergency Physicians (ACEP) 1995 Membership Activity Report, the American Medical Association (AMA) publication "1995/96 Physician Characteristics and Distribution in the U.S.," the American Hospital Association (AHA) 1994 hospital directory, a written survey of each state's medical licensing board and state medical society, and the American Board of Emergency Medicine (ABEM) annual activity report for 1995. These data were used to project workforce supply and demand estimates applicable to workforce models. RESULTS: None of the available information sources had complete data on the number and distribution of emergency physicians (EPs) currently practicing in the United States. Extrapolating the limited reliable statewide EP numbers to make nationwide projections reveals a shortage of EPs needed to fully staff the nation's existing EDs. At least 22 states had an average ratio of < 5 EPs per existing ED. Additional national projections incorporating a decreasing number of U.S. EDs indicate that the current annual number of EM residency graduates will not eliminate the deficit of EPs for at least several decades, given that projected numbers of retiring EPs annually will soon equal the total annual EM residency graduate production. CONCLUSIONS: Although the current data on EPs in practice in the United States are incomplete, the authors project a relative shortage of EPs. More accurate and complete information on the numbers and distribution of EPs in America is needed to improve workforce projections.

Certification

Effect of age on prehospital cardiac resuscitation outcome.

To compare resuscitation outcomes in elderly and younger prehospital cardiac arrest victims, we used a retrospective case series over 5 years in rural advanced life support (ALS) units and a University hospital base station. Participants included 563 adult field resuscitations. Excluded were patients with noncardiac etiologies, those less than 30 years old, and those with unknown initial rhythms. Patients were grouped by age. Return of spontaneous circulation (ROSC) and survival to hospital discharge were compared by Yates' chi-square test. ALS treatment of cardiac arrest was by regional protocols and on-line physician direction. Sixty percent (320/532) of patients were over 65 years old. The proportion with initial rhythm ventricular fibrillation (VF) was 50% in the elderly and 48% in younger patients. ROSC was achieved in 18% of elderly and 16% of younger patients; survival was 4% among the elderly and 5% for younger patients. The oldest survivor was 87 years old. Most survivors were discharged, in good Cerebral Performance Categories. There was no difference in outcome by age group when initial cardiac rhythm was considered. Early cardiopulmonary resuscitation (CPR) and ALS and initial rhythm VF were associated with the best resuscitation success. Age has less effect on resuscitation success than other well-known factors such as early CPR and ALS. Advanced age alone should probably not deter resuscitation attempts.

Adult

Attending supervision of nonemergency medicine residents in a university hospital ED.

There have been a limited number of studies assessing the impact of attending physician supervision of residents in the emergency department (ED). The objective of this study is to describe the changes in patient care when attending emergency physicians (AEPs) supervise nonemergency medicine residents in a university hospital ED. This was a prospective study including 1,000 patients, 32 second- and third-year nonemergency medicine residents and eight AEPs. The AEPs classified changes in care for each case as major, minor, or none, according to a 40-item data sheet list. There were 153 major changes and 353 minor changes by the AEP. The most common major changes were ordering laboratory or x-ray tests that showed a clinically significant abnormality, and eliciting important physical exam findings. Potentially limb- or life-threatening errors were averted by the AEP in 17 patients. Supervision of nonemergency medicine residents in the ED resulted in frequent and clinically important changes in patient care.

Diagnostic Errors

Evaluation of a prehospital chest pain protocol.

STUDY OBJECTIVES: To evaluate the diagnostic accuracy and outcomes for patients treated by use of a prehospital chest pain protocol (CPP). DESIGN: Consecutive case series for 1 year (1993) of prehospital nontrauma advanced life support (ALS) cases including hospital outcomes. SETTING: Nonurban two-tiered emergency medical services system. PARTICIPANTS: Patients treated under the prehospital CPP or with hospital diagnoses of ischemic heart disease (IHD; ICD-9 between 410 and 414). Patients with cardiac arrest or dysrhythmias were excluded. INTERVENTIONS: Patients were given, by standing orders, ECG monitoring, i.v. access, and sublingual nitroglycerin. Further therapy was guided by on-line medical direction. RESULTS: Of 3,122 ALS nontrauma patients, 620 (20%) were treated with the CPP. All patients underwent ECG monitoring, i.v. access was started in 83%, and 61% received nitroglycerin. Only 55% of patients completed the entire CPP; patients who failed to complete the CPP had the same prevalence of IHD as those who completed it. When compared with hospital diagnosis of IHD, the CPP had a sensitivity of 69% (95% confidence interval [CI], 64% to 74%), a specificity of 87% (95% CI, 86% to 88%), and a positive predictive value of 42%. The positive likelihood ratio of CPP for IHD was 5.31, and the negative likelihood ratio was .36. The hospital mortality rate for all patients was 2.2%; for those with IHD, it was 1.6%. CONCLUSION: This prehospital ALS CPP had good diagnostic accuracy, but only half of patients completed it, and the hospital mortality rate was low. These data challenge the efficacy of the CPP.

Angina Pectoris

Decrease in medical command errors with use of a "standing orders" protocol system.

The purpose of this study was to determine the physician medical command error rates and paramedic error rates after implementation of a "standing orders" protocol system for medical command. These patient-care error rates were compared with the previously reported rates for a "required call-in" medical command system (Ann Emerg Med 1992; 21(4):347-350). A secondary aim of the study was to determine if the on-scene time interval was increased by the standing orders system. Prospectively conducted audit of prehospital advanced life support (ALS) trip sheets was made at an urban ALS paramedic service with on-line physician medical command from three local hospitals. All ALS run sheets from the start time of the standing orders system (April 1, 1991) for a 1-year period ending on March 30, 1992 were reviewed as part of an ongoing quality assurance program. Cases were identified as nonjustifiably deviating from regional emergency medical services (EMS) protocols as judged by agreement of three physician reviewers (the same methodology as a previously reported command error study in the same ALS system). Medical command and paramedic errors were identified from the prehospital ALS run sheets and categorized. Two thousand one ALS runs were reviewed; 24 physician errors (1.2% of the 1,928 "command" runs) and eight paramedic errors (0.4% of runs) were identified. The physician error rate was decreased from the 2.6% rate in the previous study (P < .0001 by chi 2 analysis). The on-scene time interval did not increase with the "standing orders" system.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical Protocols

Whole-bowel irrigation as adjunctive treatment for sustained-release theophylline overdose.

STUDY OBJECTIVE: To determine a therapeutic benefit for whole-bowel irrigation (with polyethylene glycol-electrolyte lavage solution) as adjunctive treatment to multiple doses of activated charcoal following an overdose of sustained-release theophylline. DESIGN: Randomized crossover study. Three treatment arms were separated by one-week intervals. SETTING: Animal care facility housing. TYPE OF PARTICIPANTS: Eight female mongrel dogs. INTERVENTIONS: Unanesthetized dogs were given approximately 75 mg/kg of sustained-release theophylline. In treatment arm 1, 1 g/kg activated charcoal was administered by nasogastric tube at two hours after ingestion followed by 0.5-g/kg doses at five and eight hours. During treatment arm 2, beginning two hours after theophylline ingestion, 25 mL/kg whole-bowel irrigation solution was administered every 45 minutes for four doses followed by activated charcoal. In treatment arm 3, the first dose of activated charcoal was given ten minutes before beginning the whole-bowel irrigation protocol. MEASUREMENTS AND MAIN RESULTS: Serum theophylline levels were measured at zero, two, four, five, eight, 12, 16, and 24 hours after ingestion. Mean serum theophylline levels, area under the curve (P = .13), and terminal half-lives (P = .69) for each treatment group were not statistically different. This negative study had an 81% power to detect a 50% reduction in the area under the curve by whole-bowel irrigation treatment. CONCLUSION: In this model, whole-bowel irrigation did not add to the therapeutic benefits of activated charcoal.

Animals

Medical command errors in an urban advanced life support system.

STUDY OBJECTIVE: The aim of this study was to assist in focusing educational efforts for command physicians by identifying the most common types of errors made by on-line medical command. DESIGN: Retrospective survey of prehospital advanced life support (ALS) trip sheets. SETTING: An urban ALS paramedic service with on-line physician medical command rotating on a monthly basis among three hospitals. PARTICIPANTS: From September 1988 through December 1990, all ALS run sheets were reviewed as part of an ongoing quality assurance program. Cases were identified as deviating from regional emergency medical services protocols as judged by agreement of three physician reviewers. Cases were excluded if all three reviewers did not agree that the command rendered was inappropriate. INTERVENTIONS: Command errors were identified from the prehospital ALS run sheets and categorized. RESULTS: One hundred ninety-four command errors in 167 cases were identified from 3,839 runs (4.4% of all runs). Six types of errors accounted for 80% of the total errors, with the most common error (34%) being failure to address the possibility of hypoglycemia with altered level of consciousness. Error rate decreased from 7.9% to 2.6% of total runs during the study period. CONCLUSION: To reduce the medical command error rate, physician education should be directed at the six problem areas identified. Ongoing quality assurance review of medical command may result in a decrease of the command error rate.

Diagnostic Errors

Effects of prehospital medications on mortality and length of stay in congestive heart failure.

HYPOTHESIS: Prehospital medications for congestive heart failure should affect hospital outcomes (survival and length of stay). STUDY DESIGN: In a retrospective case series, hospital outcomes were compared for patients treated with prehospital nitroglycerin, furosemide, and/or morphine (252) versus those given no medications (241). SETTING: A rural/suburban emergency medical services system (population 140,000) served by three paramedic units. PARTICIPANTS: Four hundred ninety-three consecutive cases of congestive heart failure or pulmonary edema were identified by hospital discharge diagnosis from a data base of 8,315 paramedic transports with known outcome. INTERVENTIONS: Oxygen was given by protocol to 489 patients. Other medications were given by order of on-line physician medical command. RESULTS: Overall mortality was 10.9% (54 of 493). Treated and untreated patients were comparable in age, sex, cardiac rhythms, prior use of cardiac medications, and response and scene times; mortality was reduced in treated versus untreated patients (odds ratio for improved survival, 2.51; 95% confidence interval, 1.37 to 4.55; P less than .01). Positive treatment effect was greatest for 58 nonhypotensive, critical patients (odds ratio for survival, 10.25; P less than .01). No single drug combination was unique in terms of treatment benefit. Patients treated in the field received medications 36 minutes earlier than patients first treated in the emergency department. No survival benefit was evidence for noncritical, nonhypotensive patients, and patients with final diagnoses of asthma, chronic obstructive pulmonary disease, pneumonia, or bronchitis had a higher than expected mortality if erroneously treated for congestive heart failure. Differences in hospital length of stay were not significant for any group. CONCLUSION: Prehospital medications improve survival in congestive heart failure, especially in critical patients. More than one combination of medications seems effective, and early treatment is associated with improved survival. However, these medications appear to increase mortality in patients misdiagnosed in the field. Factors used in paramedica and medical command assessments require further study.

Academic Medical Centers

Medication mishaps. Avoiding inappropriate use of prehospital meds.

Although we believe in the usefulness and effectiveness of certain medications used in prehospital care, there actually have been few studies conducted that prove the efficacy of medications in this environment. Use of prehospital medications should be carefully considered by EMS providers. Medications should be used when the diagnosis or cause of symptoms is clear, the medication is clearly effective in treating them, the side effects or complications are minimal, and the transport time is sufficient to allow the medication to take effect.

Drug Utilization

Clinical characteristics of angiotensin-converting enzyme inhibitor-induced angioedema.

We present the cases of two patients with angiotensin-converting enzyme (ACE) inhibitor-induced angioedema that required intubation for life-threatening airway compromise. This side effect has been previously reported with all ACE inhibitors, but its incidence and potential for a fatal outcome may not be fully appreciated. A review of the literature reveals 227 reports of this reaction with an overall incidence of approximately 0.1% to 0.2%. The etiology is nonimmunogenic and thought to be related to accentuated bradykinin activity. There is no clinical profile that identifies patients at increased risk for this side effect. There are unique clinical characteristics to this idiosyncratic reaction: angioedema may suddenly occur even though the drug has been well tolerated for months or years; symptoms may regress spontaneously while the patient continues the medication, erroneously prompting an alternative diagnosis; the pathology has a special predilection for the tongue, a circumstance that renders orotracheal and nasotracheal intubation difficult; symptoms may progress rapidly despite aggressive medical therapy, necessitating emergency airway procedures; and a rebound phenomenon following successful medical therapy has been described. We recommend intensive medical treatment before angioedema is severe enough to thwart standard methods to ensure a protected airway. Once even minor angioedema is attributed to an ACE inhibitor, an alternative class of antihypertensive medication should be chosen. Individuals with a history of idiopathic angioedema probably should not be given ACE inhibitors.

Angioedema

Comparison of two systems for quality assurance of prehospital advanced life support services.

INTRODUCTION: The need for quality assurance (QA) systems for review of prehospital advanced life support (ALS) care has long been recognized. However, there only have been limited published studies on the operation and cost of QA systems for prehospital care. A number of different systems currently are in use, and the relative effectiveness of different QA systems has not been well determined. OBJECTIVE: The aim of this study was to compare the personnel work-time and costs of two different systems of QA for prehospital ALS services, and thereby determine which type of system was more cost-effective in the generation of QA reports. METHODS: The quality assurance program (System 1) for three independent ALS services in a rural/suburban area and the QA program (System 2) for a nearby urban ALS service were compared. Data recorded included the training level and number of hours per year devoted exclusively to QA activities by different personnel. The annual costs for other aspects of the QA systems and apportioned salary costs for time spent on QA work were recorded. RESULTS: System 1, a computer-based system, utilized 1,116 hours per year of personnel time and required [US]$17,662 in total costs per year (average cost per run reviewed of $4.38). System 2 (a manual system) utilized 569 hours per year of personnel time and had an annual cost of [US]$8,361 (or $2.15 per run reviewed). System 1 generated 852 reports per year (21% of runs) about non-compliance with protocols or charting deficiencies. System 2 generated 284 reports per year (7.3% of runs) for similar events. CONCLUSIONS: Either a computer-based or "manual" system for QA of prehospital ALS services can be utilized. A computer-based system requires more personnel time and is more expensive, but generates more reports per year than does the manual system. A computer-based system more readily can retrieve run report data for further review.

Cost-Benefit Analysis

Comparison of interventions in prehospital care by standing orders versus interventions ordered by direct [on-line] medical command.

OBJECTIVE: The aim of this study was to compare the patient care measures provided by paramedics according to standing orders versus measures ordered by direct [on-line] medical command in order to determine the types and frequency of medical command orders. DESIGN: Prospective identification of patient care measures done as part of a prehospital quality assurance program. SETTING: An urban paramedic service in the northeast United States with direct medical command from three local hospitals. PARTICIPANTS: One thousand eight paramedic reports from October 1992 through March 1993. INTERVENTIONS: All patient care interventions recorded as done by standing orders or by direct medical command orders. Errors in patient care were determined by the same criteria as in the prior two studies of the same system. RESULTS: Direct medical command gave orders in 143/1,008 (14.2%) cases. Paramedics performed 2,453/2,624 (93.5%) of the total patient care interventions using standing orders. In 61 cases (6.1%), medical command ordered a potentially beneficial intervention not specified by standing orders or not done by the paramedic. 21/171 (12.3%) command orders were for additional doses of epinephrine or atropine in cardiac arrest cases (where the initial doses had been given under standing orders), and 59/171 (34.5%) were for interventions already mandated or permitted by standing orders. The paramedic error rate was 0.6%, and the medical command error rate was 1.8% (unchanged form the prior study of the same standing-orders system). CONCLUSION: Direct medical command gave orders in 14% of cases in this standing-orders system, but 35% of command orders only reiterated the standing orders. More selective and reduced uses of on-line command could be done in this system with no change in the types or numbers of patient care interventions performed.

Clinical Protocols