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Biomedical subjects

A B Sanders

Publications and source records attributed to A B Sanders.

At least 19 recordsLinked to original sources
PubMed1997

Assisted ventilation does not improve outcome in a porcine model of single-rescuer bystander cardiopulmonary resuscitation.

BACKGROUND: Mouth-to-mouth rescue breathing is a barrier to the performance of bystander cardiopulmonary resuscitation (CPR). We evaluated the need for assisted ventilation during simulated single-rescuer bystander CPR in a swine model of prehospital cardiac arrest. METHODS AND RESULTS: Five minutes after ventricular fibrillation, swine were randomly assigned to 8 minutes of hand-bag-valve ventilation with 17% oxygen and 4% carbon dioxide plus chest compressions (CC + V), chest compressions only (CC), or no CPR (control group). Standard advanced life support was then provided. Animals successfully resuscitated received 1 hour of intensive care support and were observed for 24 hours. All 10 CC animals, 9 of the 10 CC + V animals, and 4 of the 6 control animals attained return of spontaneous circulation. Five of the 10 CC animals, 6 of the 10 CC + V animals, and none of the 6 control animals survived for 24 hours (CC versus controls, P = .058; CC + V versus controls, P < .03). All 24-hour survivors were normal or nearly normal neurologically. CONCLUSIONS: In this model of prehospital single-rescuer bystander CPR, successful initial resuscitation, 24-hour survival, and neurological outcome were similar after chest compressions only or chest compressions plus assisted ventilation. Both techniques tended to improve outcome compared with no bystander CPR.

Animals↗
PubMed1997

The development and evaluation of a geriatric emergency medicine curriculum. The SAEM Geriatric Emergency Medicine Task Force.

OBJECTIVE: To summarize the processes used to develop a curriculum and model of care for the emergency medical treatment of elder patients and to assess the efficacy of the teaching material in a pilot course. METHODS: A survey of emergency medicine (EM) residency directors and geriatric fellowship directors was used to identify key topics for inclusion in the didactic material. An interdisciplinary consensus process was used to develop didactic as well as teaching material in geriatric EM. Pretests and posttests were administered to 46 participants in the initial course to assess knowledge gain. Subjective course evaluations were also done. RESULTS: Test scores significantly increased from 54% correct on the pretest to 77% correct on the posttest (p < 0.001). Significant improvement in knowledge as judged by pretest and posttest results occurred in 6 of the 7 teaching modules. Subjective evaluations demonstrated good to excellent ratings for each module as well as the overall workshop. CONCLUSIONS: The process of developing a curriculum for geriatric EM is described. The initial training of instructors was effective in improving participants' knowledge of geriatric issues in EM. Participants considered the training to be effective. The effect of the training on the emergency care of elder persons remains to be determined.

Aged↗
PubMed1996

Active compression-decompression versus standard cardiopulmonary resuscitation in a porcine model: no improvement in outcome.

Active compression-decompression cardiopulmonary resuscitation (CPR) is a new innovative basic life-support technique during which the anterior chest wall is actively decompressed by a suction device. CPR techniques were studied in 36 swine to test the hypothesis that active compression-decompression CPR improves coronary perfusion pressure, myocardial blood flow during CPR, and 24-hour survival. After 30 seconds of untreated ventricular fibrillation, CPR was begun and continued for 12.5 minutes by one of the three following methods: (1) active compression-decompression CPR with a suction device modified to include a precision force transducer; (2) standard CPR performed with a force transducer device; and (3) standard manual CPR performed without a force transducer device. CPR-generated coronary perfusion pressure, myocardial blood flow, and the force of compression were measured at 3 and 10 minutes of resuscitation effort. Initial return of spontaneous circulation, 24-hour survival, and trauma scores were also evaluated. Active compression-decompression CPR produced consistently better results than did standard CPR performed with a force transducer, but not better than standard CPR performed manually without a force transducer. The use of a force-measuring device with standard CPR may compromise hemodynamic response and outcome.

Animals↗
PubMed1996

Ventricular fibrillation in a swine model of acute pediatric asphyxial cardiac arrest.

STUDY OBJECTIVE: To determine cardiac rhythms in a swine model of acute pediatric asphyxial cardiac arrest. DESIGN: Prospective electrocardiographic evaluation of 36 piglets. SETTING: University hospital laboratory. INTERVENTION: Piglets were acutely asphyxiated by endotracheal tube clamping until 10 min after loss of aortic pulsations. Resuscitative efforts were then provided. RESULTS: None of the animals had ventricular fibrillation (VF) when loss of aortic pulsations occurred (11 +/- 2 min after clamping). Fourteen of the 36 piglets exhibited VF during the asphyxial insult. VF converted to asystole in four piglets prior to resuscitation. Immediately prior to resuscitation, VF occurred in 10 piglets, asystole in 19 piglets, and bradyarrhythmias in seven piglets. CONCLUSION: VF occurs frequently in this piglet model of prolonged asphyxial cardiac arrest, consistent with recent observations in pediatric prehospital cardiac arrests. VF occurred late in the asphyxial process.

Animals↗
PubMed1996

Research directions in emergency medicine.

The goal of emergency medicine is to improve health while preventing and treating disease and illness in patients seeking emergency medical care. Improvements in emergency medical care and the delivery of this care can be achieved through credible and meaningful research efforts. Improved delivery of emergency medical care through research requires careful planning and the wise use of limited resources. To achieve this goal, emergency medicine must provide appropriate training of young investigators and attract support for their work. Promotion of multidisciplinary research teams will help the specialty fulfill its goals. The result will be the improvement of emergency medical care which will benefit not only the patients emergency physicians serve but also, ultimately, the nation's health.

Emergency Medicine↗
PubMed1996

A randomized, blinded trial of high-dose epinephrine versus standard-dose epinephrine in a swine model of pediatric asphyxial cardiac arrest.

OBJECTIVE: To determine whether high-dose epinephrine administration during cardiopulmonary resuscitation (CPR) in a swine pediatric asphyxial cardiac arrest model improves outcome (i.e., resuscitation rate, survival rate, and neurologic function) compared with standard-dose epinephrine. DESIGN: A randomized, blinded study. SETTING: A large animal cardiovascular laboratory at a university. SUBJECTS: Thirty domestic piglets (3 to 4 months of age) were randomized to receive standard-dose epinephrine (0.02 mg/kg) or high-dose epinephrine (0.2 mg/kg) during CPR after 10 mins of cardiac standstill with loss of aortic pulsation after endotracheal tube clamping. INTERVENTIONS: Two minutes of CPR were provided, followed by advanced pediatric life support. Successfully resuscitated animals were supported in an intensive care unit (ICU) setting for 2 hrs and then observed for 24 hrs. MEASUREMENTS AND MAIN RESULTS: Electrocardiogram, thoracic aortic blood pressure, and right atrial blood pressure were monitored continuously until the intensive care period ended. Survival rate and neurologic outcome were determined. Return of spontaneous circulation was obtained in 13 of 15 high-dose epinephrine piglets vs. ten of 15 standard-dose epinephrine piglets (p < .20). Four of 13 high-dose piglets died in the ICU period after initial resuscitation vs. 0 of ten standard-dose piglets (p < or = .05). Nine high-dose piglets survived 2 hrs vs. ten standard-dose piglets. Three piglets in each group survived for 24 hrs, but all were severely neurologically impaired. Two minutes after resuscitation, piglets treated with high-dose epinephrine had higher heart rates (210 +/- 24 vs. 189 +/- 40 beats/min, p < .05) and higher aortic diastolic pressures (121 +/- 39 vs. 74 +/- 40 mm Hg, p < .01). Within 10 mins of return of spontaneous circulation, severe tachycardia (> 240 beats/min) was more frequently noted in the high-dose group than in the standard-dose group (p < .05). All four high-dose piglets that died in the ICU period experienced ventricular fibrillation within 10 mins of return of spontaneous circulation. CONCLUSIONS: High-dose epinephrine did not improve 2-hr survival rate, 24-hr survival rate, or neurologic outcome. High-dose epinephrine resulted in severe tachycardia and hypertension immediately after resuscitation and in a higher mortality rate immediately after resuscitation.

Animals↗
PubMed1996

Initial end-tidal CO2 is markedly elevated during cardiopulmonary resuscitation after asphyxial cardiac arrest.

OBJECTIVES: To compare the initial end-tidal CO2 (PetCO2) during cardiopulmonary resuscitation in asphyxial versus ventricular fibrillatory cardiac arrest. DESIGN: A cohort study. SETTING: University research laboratory. SUBJECTS: Forty domestic piglets. INTERVENTIONS: Asphyxial cardiac arrest was produced by clamping the endotracheal tube in 20 piglets and was continued for 10 minutes after loss of aortic pulsations occurred. Ventricular fibrillation (VF) was induced by applying 60 Hz of alternating current via a pacing wire to the myocardium of the other 20 piglets, and continued for a 15-minute downtime. Cardiopulmonary resuscitation (CPR) was then provided to each group for two minutes, followed by standard advanced cardiac life support protocols. MEASUREMENTS AND MAIN RESULTS: All piglets were instrumented for continuous monitoring of PetCO2, electrocardiogram, central venous pressure, and aortic pressure. PetCO2 of the first breath of CPR was 91 +/- 20 mmHg in the asphyxial group versus 34 +/- 14 mmHg in the VF group (P < 0.001). The asphyxial group continued to exhibit significantly greater PetCO2 for the first five breaths of resuscitation, after which there were no differences. The coronary perfusion pressures during the first breaths of CPR did not differ between the two groups. High initial PetCO2 did not correlate with return of spontaneous circulation. CONCLUSIONS: End-tidal CO2 during the first five breaths of CPR is much higher after an asphyxial cardiac arrest than VF. In each case, the initial PetCO2 appears to reflect alveolar CO2 prior to CPR. After one minute of CPR, PetCO2 is useful in monitoring the effectiveness of CPR.

Animals↗
PubMed1995

Bystander cardiopulmonary resuscitation. Concerns about mouth-to-mouth contact.

BACKGROUND: Bystander cardiopulmonary resuscitation (CPR) is performed on only a small percentage of patients who suffer cardiac arrest. We conducted a study to elucidate attitudes toward and potential obstacles to performance of bystander CPR. METHODS: Attitude survey of 975 people on the University Heart Center, University of Arizona, Tucson, mailing list. Participants were asked about their willingness to perform CPR under four conditions, with varying relationships (stranger vs relative or friend) and CPR techniques (chest compressions plus mouth-to-mouth ventilation [CC+V] vs chest compressions alone [CC]). RESULTS: Participants rated willingness to perform CPR and concern about disease transmission. Both relationship and CPR technique affected willingness to respond. Only 15% would "definitely" provide CC+V with strangers compared with 68% who would "definitely" perform CC. Even with relatives or friends, only 74% would "definitely" provide CC+V compared with 88% who would "definitely" provide CC. Eighty-two percent of participants were at least "moderately" concerned about disease transmission. CONCLUSION: Concerns regarding mouth-to-mouth ventilation appear to create substantial barriers to performance of bystander CPR. Intensified educational efforts and investigations of new approaches to bystander CPR are warranted.

Adult↗
PubMed1995

The need for ventilatory support during bystander CPR.

STUDY OBJECTIVE: To compare CPR with chest compressions plus ventilatory support (CC+V) and chest compressions alone (CC). DESIGN: Prospective, randomized study. SETTING: Research laboratory. INTERVENTIONS: After 2 minutes of ventricular fibrillation, 18 domestic swine (20 to 35 kg) were treated first with CC or CC+V for 10 minutes, then with standard advanced cardiac life support. RESULTS: Hemodynamics, survival, and neurologic outcome were determined. All 8 swine subjected to CC+V and all 10 subjected to CC showed return of spontaneous circulation. One animal in each group died within 1 hour. Seven of 8 animals in the CC+V group survived for 24 and 48 hours, compared with 9 of 10 CC animals at 24 hours and 8 of 10 at 48 hours. All 48-hour survivors were neurologically normal. CONCLUSION: In this experimental model of bystander CPR, we could not detect a difference in hemodynamics, 48-hour survival, or neurologic outcome when CPR was applied with and without ventilatory support.

Animals↗
PubMed1995

Bilateral vocal cord paralysis following blunt trauma to the neck.

Blunt trauma to the anterior neck has been known to cause upper-airway obstruction requiring emergency tracheostomy. We report the case of a 26-year-old man who sustained blunt trauma to the anterior neck in whom upper-airway obstruction developed. Although computed tomography of the neck revealed a thyroid cartilage fracture and a retropharyngeal hematoma, fiberoptic examination of the larynx identified vocal cord paralysis as the primary cause of his upper-airway obstruction. Emergency tracheostomy was performed, and the patient recovered uneventfully. A Medline search of the literature for the past 3 years failed to identify any individual case reports of bilateral vocal cord paralysis secondary to blunt anterior neck trauma.

Adult↗
PubMed1995

Chest compression and ventilation rates during cardiopulmonary resuscitation: the effects of audible tone guidance.

OBJECTIVES: To determine: 1) whether chest compressions during CPR are being performed according to American Heart Association (AHA) guidelines during cardiac arrest; and 2) the effect of an audio prompt to guide chest compressions on compliance with AHA guidelines and hemodynamic parameters associated with successful resuscitation. METHODS: An observational clinical report and laboratory study was conducted. A research observer responded to a convenience sample of cardiac arrests within a 300-bed hospital and counted the rate of chest compressions and ventilations during CPR. To evaluate the effect of an audio prompt on CPR, health care providers performed chest compression without guidance using a porcine cardiac arrest model for 1 minute, followed by a second minute in which audio guidance was added. Chest compression rates, arterial and venous blood pressures, end-tidal CO2 (ETCO2) levels, and coronary perfusion pressures were measured and compared for the two periods. RESULTS: Twelve in-hospital cardiac arrests were observed in the clinical part of the study. Only two of 12 patients had chest compressions performed within AHA guidelines. No patient had respirations performed within AHA guidelines. In the laboratory, 41 volunteers were tested, with 66% performing chest compressions outside the AHA standards for compression rate without audible tone guidance. With guided chest compressions, the mean (+/- SD) chest compression rate increased from 74 +/- 22 to 100 +/- 3/min (p < 0.01). End-tidal CO2 levels increased from 15 +/- 7 to 17 +/- 7 torr (p < 0.01). Coronary perfusion pressure increased minimally with audible tone-guided chest compressions. CONCLUSIONS: The majority of Basic Cardiac Life Support--certified health care professionals did not perform CPR according to AHA-recommended guidelines. The use of audible tones to guide chest compression resulted in significantly higher chest compression rates and ETCO2 levels.

American Heart Association↗
PubMed1994

A prospective study of ultrasonography in the ED by emergency physicians.

The objective of this study was to examine the use of limited, goal-directed, two-dimensional ultrasound studies performed by emergency physicians and to assess the frequency, variety, and accuracy of their readings. A 1-year prospective study was performed by using an emergency department (ED) ultrasound machine with a 3.5-mHz mechanical oscillating sector transducer and a 5.0-mHz vaginal transducer. In a series of proctoring sessions, radiologists trained emergency physicians to do limited, goal-directed ultrasonography. Laser print ultrasonograms were collected from all ED ultrasound examinations performed during a 1-year period and were compared with either formal ultrasonograms performed in the radiology department, the patient's hospital record, or both. Sensitivity, specificity, and positive predictive value (PPV), as well as negative predictive values (NPV), were calculated. The setting was a 104-bed community hospital with an ED volume of 25,000 patients annually, and patients whom the emergency physician believed needed ultrasound studies in the ED were entered. ED ultrasonography was performed in 167 patients by 14 physicians during a 1-year period. For 132 patients who completed formal follow-up, the overall diagnostic accuracy of interpretations of ED ultrasonograms yielded a sensitivity of .95, specificity of .98, PPV of .99, and NPV of .89. Eleven categories of ultrasound use were reported. The three studies most commonly performed were for gallbladder disease (53%), intrauterine pregnancy (28%), and abdominal aortic aneurysms (7%). Accuracy of ED gallbladder ultrasonograms for 65 patients showed a sensitivity of .86, specificity of .97, PPV of .97, and NPV of .85.(ABSTRACT TRUNCATED AT 250 WORDS)

California↗
PubMed1994

The efficacy of an ACLS training program for resuscitation from cardiac arrest in a rural community.

STUDY OBJECTIVE: To determine whether an advanced cardiac life support (ACLS) course in a rural hospital will improve resuscitation success from cardiac arrest. DESIGN: A retrospective case review of all patients in cardiac arrest during a 13-month period before and after the institution of an ACLS training program. SETTING: Emergency department of a 42-bed rural, community hospital in a community with no prehospital advanced life support or early defibrillation. PARTICIPANTS: All patients in cardiac arrest were entered into the data base. Twenty-nine patients were included in the pre-ACLS period and 35 in the post-ACLS period. There were no significant differences in age, gender, initial rhythm, comorbid diseases, witnessed versus unwitnessed arrest, or total arrest time in the patients in the pre-ACLS period compared with those in the post-ACLS period. INTERVENTION: ACLS provider training. MAIN RESULTS: Patients in cardiac arrest who had ventricular fibrillation/tachycardia as their initial rhythm had significant improvement in resuscitation success compared with patients in ventricular fibrillation/tachycardia in the pre-ACLS period (six of 15 versus none of nine, P < .05). Out-of-hospital cardiac arrest resuscitation was more successful in the post-ACLS period than in the pre-ACLS period (five of 30 versus none of 25, P < .05). Overall, seven of 35 patients (20%) were resuscitated successfully in the post-ACLS period, with two patients surviving to hospital discharge. This was not significantly different than the two of 29 patients (7%) resuscitated in the pre-ACLS period, with one patient surviving to discharge. CONCLUSION: The institution of an ACLS-provider course in a rural community hospital was associated with improvement in initial resuscitation for patients with ventricular fibrillation/tachycardia and out-of-hospital arrest.

Cardiopulmonary Resuscitation↗
PubMed1994

Characteristics influencing career decisions of academic and nonacademic emergency physicians.

STUDY OBJECTIVE: To determine characteristics motivating physicians to choose careers in academic and nonacademic emergency medicine. DESIGN: A written survey of 1,017 active members of the Society for Academic Emergency medicine and of a random sample of 2,000 members of the American College of Emergency Physicians was performed. Questions were asked regarding medical school, residency, and fellowship training; the importance of specific factors in influencing career decisions; and perceived obstacles to emergency medicine research. Responses from nonfaculty and adjunct, clinical, and research faculty were compared using chi 2 analysis for discrete variables and a four-group analysis of variance for continuous variables. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Responses were obtained from 1,203 physicians (41.3%). Those choosing academic careers were significantly more likely to complete a residency in emergency medicine or internal medicine and fellowship training in research or toxicology compared with nonacademic physicians. Nonfaculty and clinical faculty considered family obligations, leisure time, and personal income to be the most important factors influencing their career decisions; research faculty considered role models and the value of research to be most important. There was no difference in indebtedness among the groups. Finding time and funding, administrative obligations, and pressures to do clinical work were the most important obstacles to research productivity. CONCLUSION: Factors influencing career decisions can be used to plan strategies to meet the future needs of academic emergency medicine.

Adult↗
PubMed1994

Role of emergency medicine residency programs in determining emergency medicine career choice among medical students.

STUDY OBJECTIVE: To characterize the role of emergency medicine residency programs in determining emergency medicine career choice among medical students. DESIGN: Observational, cross-sectional, descriptive study. Information on student career choice was obtained through a targeted query of the National Resident Matching Program data base, simultaneously stratified by specialty and school, and adjusted for class size. PARTICIPANTS: All accredited emergency medicine residency programs and four-year allopathic medical schools. RESULTS: Fifty-two schools (42%) had a closely affiliated emergency medicine residency program, ie, one based primarily at the institution's main teaching hospital(s). This configuration was associated with a 70% increase in the median proportion of students choosing emergency medicine as a career when compared to the 73 schools with no closely affiliated emergency medicine residency (5.1% vs 3.0%, P < .0001). When institutions were stratified by overall commitment to emergency medicine, the median proportion of students choosing emergency medicine as a career was 2.9% for institutions with a minimal commitment to emergency medicine (neither an academic department of emergency medicine nor a closely affiliated emergency medicine residency), 4.1% for institutions with a moderate commitment to emergency medicine (either a department of emergency medicine or an emergency medicine residency, but not both), and 5.7% for institutions with a substantial commitment to emergency medicine (a department of emergency medicine and an emergency medicine residency) (P < .0001). When institutional commitment to emergency medicine was examined in a simple multivariate model, only the presence of an emergency medicine residency was associated independently with student career choice (P < .001). CONCLUSION: An emergency medicine residency program that is closely affiliated with a medical school is strongly and independently associated with a quantitatively and statistically significant increase in the proportion of students from that school who choose a career in emergency medicine. These data support the proposition that, if emergency medicine is to meet national manpower shortage needs by attracting students to the specialty, it must establish residency programs within the primary teaching hospital(s) of medical schools. Such a configuration does not currently exist in the majority of schools.

Career Choice↗
PubMed1994

High-dose epinephrine results in greater early mortality after resuscitation from prolonged cardiac arrest in pigs: a prospective, randomized study.

OBJECTIVE: To determine whether high-dose epinephrine (0.2 mg/kg) during cardiopulmonary resuscitation (CPR) results in improved outcome, compared with standard-dose epinephrine (0.02 mg/kg). DESIGN: A prospective, randomized, blinded study. SETTING: Research laboratory of a university medical center. SUBJECTS AND INTERVENTIONS: Thirty domestic swine were randomized to receive standard- or high-dose epinephrine during CPR after 15 mins of fibrillatory cardiac arrest. Three minutes of CPR were provided, followed by advanced cardiac life support per American Heart Association guidelines. Animals that were successfully resuscitated were supported for 2 hrs in an intensive care unit (ICU) setting, and then observed for 24 hrs. MEASUREMENTS AND MAIN RESULTS: Electrocardiogram, aortic blood pressure, right atrial blood pressure, and end-tidal CO2 were monitored continuously until the intensive care period ended. Survival and neurologic outcome were determined. Return of spontaneous circulation was attained in 14 of 15 animals in each group. Four of 14 high-dose epinephrine pigs died during the ICU period after return of spontaneous circulation vs. zero of the 14 standard-dose pigs (p < .05). Six standard-dose pigs survived 24 hrs vs. four high-dose pigs. Twenty-four-hour survival rate and neurologic outcome were not significantly different. Within 10 mins of defibrillation, severe hypertension (diastolic pressure > 120 mmHg) occurred in 12 of 14 high-dose pigs vs. two of 14 standard-dose pigs (p < .01). Severe tachycardia (heart rate > 250 beats/min) occurred in seven of 14 high-dose pigs vs. zero of 14 standard-dose pigs (p < .01). All four high-dose epinephrine pigs that died during the ICU period experienced both severe hypertension and tachycardia immediately postresuscitation. CONCLUSIONS: High-dose epinephrine did not improve 24-hr survival rate or neurologic outcome. Immediately after return of spontaneous circulation, most animals in the high-dose epinephrine group exhibited a hyperadrenergic state that included severe hypertension and tachycardia. High-dose epinephrine resulted in a greater early mortality rate.

Animals↗