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K N Hall

Publications and source records attributed to K N Hall.

11 recordsLinked to original sources
PubMed1999

Research fundamentals: IV. Choosing a research design.

Once a research question or hypothesis has been derived, the investigator must determine which research methodology can best answer his or her question. Prospective, randomized, controlled trials are often considered the sine qua non of research design. However, this study design is not always feasible, and often an alternate design will adequately answer the question at significantly less cost. All research designs have potential advantages and limitations. The decision of which study design to use is often a compromise between science and resources. This article was prepared by members of the SAEM Research Committee to describe the fundamental research concepts of research design. This paper defines different research methodologies and discusses their different uses, strengths, and weaknesses. It also describes the process of randomization and blinding. Finally, the concept of bias and its remedies is delineated.

Clinical Trials as Topic↗
PubMed1996

Pattern of basic life support ambulance use in an urban pediatric population.

To evaluate the pattern of use of basic life support (BLS) ambulances in a pediatric population, emergency medical service (EMS) and pediatric emergency department (PED) records from an urban hospital PED for all children transported to PED by ambulance during a 1-month study period were retrospectively reviewed. Excluded were: (1) advanced life support transport, (2) transport from other medical facility, (3) patients with chronic medical disability without acute decompensation, and (4) patients in police custody. BLS transport was considered inappropriate if: (1) no intervention by BLS technicians, (2) minimal to no intervention in the PED, and (3) discharge without prescription medication. Of 376 ambulance transports evaluated, 238 (63%) met entry criteria, and 105 (44%) transports met criteria for being inappropriate. The mean charge for appropriate transport was $240.68, and for inappropriate, $237.12 (P = .2). The total charge for inappropriate transports was $26,523.20. Patients on federal assistance had a significantly higher rate of inappropriate transport (51%) compared with patients who had commercial insurance (30%) and those who self paid (42%). Trauma was the most common cause for transport, 48% of which was inappropriate. It was concluded that inappropriate BLS transport of pediatric patients is common. This use is costly and may disrupt the delivery of EMS care to the remainder of the community. Efforts aimed at public education and providing alternative means of transport may significantly reduce charges and improve the delivery of EMS care.

Ambulances↗
PubMed1995

Serum potassium concentration as a predictor of resuscitation outcome in hypothermic cardiac arrest.

The purpose of this study was to determine whether serum potassium concentration (SK) can predict resuscitation outcome in a canine model of severe hypothermic cardiac arrest. Fifteen adult mongrel anesthetized dogs were immersed to the neck in a 4 degrees C water bath and ventilated with room air, with ventilation halved at 45 min and stopped at 90 min. After cardiac arrest, 14 of the dogs were kept in the water bath for periods of 2-7 h, and another was held in arrest for 13 h. Following 10 min of closed chest cardiopulmonary resuscitation (CPR) (simulating a short transport time to a hospital), animals were placed on cardiopulmonary bypass and rapidly rewarmed. With appearance of ventricular fibrillation, animals were defibrillated up to three times. Standard advanced cardiac life support was initiated at a core temperature (Tc) of 30 degrees C. Eight of the 15 dogs had return of spontaneous circulation (ROSC), at Tc ranging from 30.4 to 36.5 degrees C. The eight dogs with ROSC did not differ from the seven without ROSC in time to arrest (128 +/- 48 versus 128 +/- 23 min) (mean +/- SD) or Tc at arrest (18.1 +/- 2.2 versus 17.9 +/- 3.1 degrees C), but had higher Tc at the end of the arrest period (9.7 +/- 3.0 versus 5.2 +/- 2.0 degrees C), reflecting a shorter arrest period in the dogs with ROSC (225 +/- 95 versus 420 +/- 193 min). SK (mEq liter(-1)) did not differ between dogs with and without ROSC at baseline (3.5 +/- 0.4 versus 3.7 +/- 0.4) or at arrest (3.4 +/- 0.7 versus 4.3 +/- 2.2), but there was a trend toward higher SK at the end of arrest in the group without ROSC (4.6 +/- 1.5 versus 9.4 +/- 6.3; range 3.2-7.8 versus 3.5-21.4; p = .053). SK was similar after 10 min of CPR in the groups with and without ROSC (6.6 +/- 2.9 versus 9.0 +/- 2.4; range 2.5-11.1 versus 4.5-11.0; p = .107). SK after 10 min of CPR was higher in some animals with ROSC (9.6 and 11.1) than in others which did not have ROSC (4.5 and 7.9). We conclude that very high SK following prolonged hypothermic cardiac arrest may be suggestive of an inability to resuscitate. However, SK after both prolonged hypothermic cardiac arrest and a brief period of CPR is not a good predictor of resuscitation using cardiopulmonary bypass rewarming in an animal model.

Animals↗
PubMed1992

Factors associated with career longevity in residency-trained emergency physicians.

STUDY OBJECTIVE: To test the hypothesis that residency-trained emergency physicians who left the practice of emergency medicine do not differ significantly from those who continue to practice. DESIGN: A retrospective cohort study using a mailed questionnaire. TYPE OF PARTICIPANTS: Eight hundred fifty-eight emergency medicine residency graduates from 1978 through 1982. METHODS: A mailed questionnaire was used to obtain data from the study population. Individuals who did not respond to the first mailing were sent a second survey six weeks later. A sample of 10% of nonrespondents was contacted by telephone and compared with respondents on five variables. Respondents were divided into physicians who continued to practice emergency medicine and those who had elected to leave the specialty. The variables used to compare the two groups included personal and professional demographics, career satisfaction, and satisfaction with training. chi 2, Fisher's exact t-test, and logistic regression were used to analyze the data with an a priori level of significance set at .05. MEASUREMENTS AND MAIN RESULTS: There were 539 complete responses for a response rate of 62.8%. No statistical differences between responders and nonresponders were identified. The ten-year survival rate of respondents was 84.9%. Those who left emergency medicine were less likely to be board certified in emergency medicine (P less than .001), were more likely to be board certified in another field (P = .001), were less likely to work with residents during their emergency medicine practice (P = .009), and were more likely to report an annual gross income of less than $100,000 per year (P less than .001). Emergency physicians who have left the field were less likely to report being satisfied or very satisfied with their initial choice of emergency medicine as a specialty (P = .001). There was no difference in satisfaction with the quality of emergency medicine residency training (P = .183). CONCLUSION: Career longevity of residency-trained emergency physicians has been greater than early predictions. Interactions with residents, higher income, satisfaction with training decision, and board certification in emergency medicine are variables associated with a higher retention rate.

Adult↗
PubMed1990

Closed thoracic cavity lavage in the treatment of severe hypothermia in human beings.

Life-threatening hypothermia can be treated by active and passive rewarming techniques, the treatment of choice being partial cardiopulmonary bypass. The use of closed thoracic cavity lavage has been evaluated in animals, but no formal presentations in human beings have been reported. We report two cases in which rapid rewarming in severe hypothermia was accomplished when cardiopulmonary bypass was not available.

Adult↗
PubMedDate not supplied

Descriptive analysis of residency-trained emergency medicine physicians.

The purpose of this study was to analyze the demographics, practice characteristics, and job satisfaction of physicians who completed emergency medicine residencies. A questionnaire was mailed to 858 physicians who graduated from residencies between 1978 and 1982. A 62.8% response rate (n = 539) was achieved. The majority of respondents were satisfied or very satisfied with their choice of a career in emergency medicine and with the quality of their residency training. Over 22% of respondents cited lack of preparation to perform administrative tasks as a significant weakness of their residency training. The results of survey indicate that emergency medicine physicians are engaged primarily in clinical practice, but that administrative duties increase rapidly in the years following residency graduation. Emergency medicine physicians are still highly concentrated in states in which emergency medicine residencies are located. The percentage of graduates choosing academic careers is smaller than reported in studies of earlier graduates.

Career Choice↗
PubMedDate not supplied

Residency-trained emergency physicians: their demographics, practice evolution, and attrition from emergency medicine.

Concern exists about the ability of Emergency Physicians (EPs) to maintain a career in Emergency Medicine (EM) over a professional lifetime. The objectives of this study were to assess the practice characteristics of residency trained EPs, to document how the EP's responsibilities evolve throughout a career, and to assess career longevity. A retrospective cohort study using a mailed questionnaire was used to document practice characteristics, evolution of responsibility, and career longevity from all physicians who graduated from allopathic EM residencies between 1978-1988 (inclusive). Non-responders were compared to responders to assess the extent of selection bias. The response rate was 58.1% (1635/2812). There were no differences between responders and non-responders on any of five demographic variables. Responders who were more likely to remain in EM included those who had higher reimbursement, were board certified in EM, or did not train in another specialty or do a fellowship outside of EM. Throughout the 15-year careers studied, EPs noted a significant shift in the time spent doing clinical work (decreased) and the time doing administrative work (increase). The attrition from EM practice for this cohort was < 1% per year.

Adult↗