Thompson J, Petrie DA, Ackroyd-Stolarz S, Bardua DJ Out-of-Hospital Continuous Positive Airway Pressure Ventilation Versus Usual Care in Acute Respiratory Failure: A Randomized Controlled Trial
Article Outline
Editor's Capsule Summary What is already known on this topic
Application of continuous positive airway pressure (CPAP) for patients with acute respiratory distress reduces the need for tracheal intubation and mechanical ventilation. Case series have demonstrated CPAP's feasibility in out-of-hospital settings.
What question this study addressed
Seventy-one out-of-hospital patients with severe respiratory distress, randomized to receive CPAP or usual care, were assessed to determine need for tracheal intubation and mortality.
What this study adds to our knowledge
Within the CPAP group, the rate of intubation was 30% less than the usual care group, and mortality was 20% lower.
How this might change clinical practice
Emergency medical services systems and their medical directors should consider making CPAP available as part of the treatment for out-of-hospital severe respiratory distress patients, particularly in systems with long transport times.
Discussion Points
A. Describe the mechanism of action of noninvasive ventilation in the treatment of patients with respiratory distress. Specifically, detail the key differences between CPAP and BIPAP. B. Noninvasive ventilation has been advocated for the treatment of ED patients presenting with respiratory distress caused by various cardiopulmonary etiologies. Briefly review the recent literature advocating the use of CPAP/BIPAP in the treatment of acute respiratory distress in the ED.
C. Discuss the contraindications to initiating noninvasive ventilation in the ED and which patients are not suitable candidates for this treatment. How might these contraindications influence your decision to initiate CPAP/BIPAP in the out-of-hospital setting, immediately on arrival in the ED, or after the patient has failed common pharmaceutical treatments? A. Discuss some of the problems of obtaining out-of-hospital consent and the effect on clinical trials in the out-of-hospital setting. Specifically, what steps might a researcher have to take to obtain institutional review board waiver of consent for studies conducted in the field? B. Obtaining informed consent from potential research subjects is vital to conducting ethical and moral scientific research. Briefly detail the necessary components of an informed consent for a clinical trial. C. In 1976, a federal government commission authored the Belmont Report—Ethical Principles and Guidelines for the protection of human subjects of research. Briefly discuss the basic principles about the ethical treatment and protection of research subjects, including a review of important historical events such as the Nuremberg Code and the Tuskegee Syphilis Study. A. Why did the authors not blind the study? Could they have? B. How might the lack of blinding affect the primary outcome? Consider the behavior of the paramedics faced with identical patients who were not doing well, one who was in the CPAP limb and one in the usual care limb. Consider the behavior of an emergency physician who receives 2 similar patients, one receiving CPAP and the other not. C. The authors include an online supplementary Table E1, which shows many of the important patient characteristics of each patient. Why is it important that the authors included such a table in this study? D. Do you find the organization of Table E1 helpful? Is the table easy to interpret? How is it organized? How might the organization of this table be improved?
E. Can you use the data in Table E1 to construct tables or graphs that explore the ways that the lack of blinding might have confounded this study and provide evidence about the likelihood that paramedic or emergency physician behavior might have influenced the decision to intubate in ways unrelated to the effect of the CPAP on the patient's condition? A. What are the anticipated systems issues in the transfer of out-of-hospital CPAP devices to existing hospital CPAP units? Consider whether out-of-hospital and ED CPAP devices might be incompatible necessitating each patient to be wastefully treated with 2 sets of equipment. If the CPAP devices are not compatible, how might the need for EMS to maintain CPAP until hospital respiratory therapy services take charge to increase “out of service” time and impact EMS system performance? B. According to your response to question 4a, what would you propose as solutions to these system issues? C. Out-of-hospital care systems differ. Consider how personnel (volunteer versus professional, Basic Life Support versus Advanced Life Support) and transport time (rapid urban versus lengthy rural) might affect the utility of out-of-hospital CPAP. A. In your opinion, what are the most important conclusions from this article? How might the limitations mentioned by the authors affect your decision about whether to change your clinical practice with regard to the use of CPAP/BIPAP both in the out-of-hospital and ED settings? B. In some patients with acute respiratory distress, it is difficult to discern whether the underlying cause is cardiac, pulmonary, or a combination of both. A relative contraindication to CPAP/BIPAP use is acute coronary ischemia. How might the concern for potentially worsening acute dyspnea caused by cardiac ischemia alter the decision to initiate CPAP in patients with known coronary artery disease? C. What additional information or data analyses would you like the authors to provide before you decide to change your EMS system's clinical practice?
SEE RELATED ARTICLE, P. 232.Editor's Note: You are reading the fifth installment of Annals of Emergency Medicine Journal Club. This bimonthly feature seeks to improve the critical appraisal skills of emergency physicians and other interested readers through a guided critique of actual Annals of Emergency Medicine articles. Each Journal Club will pose questions that encourage readers—be they clinicians, academics, residents, or medical students—to critically appraise the literature.During a 2- to 3-year cycle, we plan to ask questions that cover the main topics in research methodology and critical appraisal of the literature. To do this, we will select articles that use a variety of study designs and analytic techniques. These may or may not be the most clinically important articles in a specific issue, but they are articles that serve the mission of covering the clinical epidemiology curriculum.Journal Club entries are published in 2 phases. In the first phase, a list of questions about the article is published in the issue in which the article appears. Questions are rated “novice,” () “intermediate,” () and “advanced” () so that individuals planning a journal club can assign the right question to the right student. The answers to this journal club will be published in the February 2009 issue. US residency directors will have immediate access to the answers through the Council of Emergency Medicine Residency Directors Share Point Web site. International residency directors can gain access to the questions by going to http://www.emergencymedicine.ucla.edu/annalsjc/ and following the directions. Thus, if a program conducts its journal club within 5 months of the publication of the questions, no one will have access to the published answers except the residency director. The purpose of delaying the publication of the answers is to promote discussion and critical review of the literature by residents and medical students and discourage regurgitation of the published answers.It is our hope that the Journal Club will broaden Annals of Emergency Medicine's appeal to residents and medical students. We are interested in receiving feedback about this feature. Please e-mail journalclub@acep.org with your comments.
PII: S0196-0644(08)01497-2
doi:10.1016/j.annemergmed.2008.07.004
© 2008 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.
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Out-of-Hospital Continuous Positive Airway Pressure Ventilation Versus Usual Care in Acute Respiratory Failure: A Randomized Controlled Trial
, 04 April 2008
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