American Journal of Emergency Medicine (2012) 30, 2064–2077
www.elsevier.com/locate/ajem
Correspondence
Further thoughts on whether outcomes of near syncope parallel syncope To the Editor, We greatly appreciate the interest expressed in our study well articulated in the above letter. To review, our objective was to determine the incidence of critical interventions or adverse outcomes associated with near syncope and to compare these outcomes with those patients with true syncope [1]. The letter above suggests a potential bias in comparing patients with near syncope and those with syncope. Both studies used the same questionnaires and similar triage criteria for identifying patients. We preformed a detailed analysis presented in percentages in the table looking at demographics and comorbidities in patients with near syncope and syncope. Here, we demonstrated similar demographics, medical presentations, and comorbidities between patients with near syncope and syncope, including chest pain, abnormal heart rhythm or new electrocardiogram changes, and a history of coronary artery disease. Although no significant differences between the 2 groups were detected, we acknowledge that some unidentified variables that may have been unevenly distributed among the 2 cohorts could have influenced this study's results. The letter suggests that a more appropriate conclusion, based on the results of this study, would be that we should treat patients with syncope like those with near syncope because patients with near syncope despite having a similar rate of adverse outcomes, were more likely to be safely discharged home. Such a conclusion is possible based on our results; however, we chose a different conclusion for the following reasons. First, there maybe some confounding factors that may have influenced the discharge rates of patients with near syncope. For example, it is possible that practitioners in our emergency department may have had a bias in their decision-making process, as the Boston Syncope Criteria are now used as the standard admitting guideline for syncope in our emergency department and physicians may have already applied these criteria to patients with near syncope in their practice despite a lack of published evidence supporting their equivalence in outcomes .Please see the enclosed reference for further details [2]. In addition, because 0735-6757/$ – see front matter © 2012 Published by Elsevier Inc.
it has traditionally been theorized that near syncope is associated with fewer comorbidities and should be considered less ominous, therefore, we felt that it was most important to emphasize that, contrary to popular belief, near syncope should be considered as seriously as syncope. This conclusion matches our stated objectives, as well. Shamai A. Grossman MD, MS Matthew Babineau MD Laura Kulchycki MD Larry Mottley MD Adarsh Kancharla MD Andrea Nencioni MD Nathan Shapiro MD, MPH Department of Emergency Medicine Beth Israel Deaconess Medical Center Harvard Medical School, Boston, MA 02215, USA E-mail address:
[email protected] http://dx.doi.org/10.1016/j.ajem.2012.05.035
References [1] Grossman SA, Babineau M, Burke L, Kancharla A, Mottley L, Nencioni A, et al. Do outcomes of near syncope parallel syncope? Am J Emerg Med 2012;30:203. [2] Grossman SA, Bar J, Fischer C, et al. Applying the Boston Syncope Criteria to near syncope. J Emerg Med 2012;42:345-52.
Do outcomes of near syncope parallel syncope? To the Editor, We read with great interest the article by Grossman et al [1] on the incidence of critical interventions or adverse outcomes associated with near syncope comparing these outcomes with the ones of patients with true syncope. It deals with a clinically relevant problem because even in the most recent guidelines, there is not a consensus on the definition of near syncope and its clinical consequences [2].
Correspondence Thereby, many studies evaluating the prognosis of syncope enrolled patients with near syncope, whereas others did not [3,4]. However, we wonder if comparing patients presenting with near syncope to patients with syncope from a different cohort [5] could lead to any bias. Moreover, we found that the outcomes considered in these 2 studies are different. The near syncope study evaluated acute renal failure and congestive heart failure, whereas these outcomes were not considered in the syncope study. At this regard, it is also important to compare the characteristics of the 2 populations to evaluate if they have a comparable risk profile, and this is performed in Table 1. Unfortunately, it is not clear if chest pain, abnormal heart rhythm, or new electrocardiographic changes history of coronary artery disease are equally represented in the 2 groups because of incongruities between absolute numbers and percentages. The authors' conclusions state that patients with near syncope were as likely as patients with syncope to experience adverse outcomes. Indeed, because the trial was designed to detect significant differences between the 2 groups and not to confirm their equality (it is not a noninferiority trial), we cannot be sure that there is not any difference between the 2 groups. It would be more appropriate to state that we were not able to find significantly different adverse outcomes in the 2 groups. The authors suggested to treat people presenting with near syncope like the ones with syncope. However, considering that near syncope patients were less likely to be admitted, supposing a similar risk of adverse outcomes for syncope and near syncope and knowing that in this latter cohort, no patient discharged home from the emergency department was subsequently found to have adverse outcomes on 30-day follow-up, would not it be a better conclusion to state that we should treat patients with syncope like the ones with near syncope? Giulia Cernuschi MD Mattia Bonzi MD Elisa Fiorelli MD Simone Birocchi MD Medicina Interna II Ospedale L. Sacco Università degli Studi di Milano 20157 Milan, MI, Italy E-mail address:
[email protected] http://dx.doi.org/10.1016/j.ajem.2012.05.036
References [1] Grossman SA, Babineau M, Burke L, Kancharla A, Mottley L, Nencioni A, et al. Do outcomes of near syncope parallel syncope? Am J Emerg Med 2012;30:203.
2065 [2] Guidelines for the diagnosis and management of syncope. The task force for the diagnosis and management of syncope of the European Society of Cardiology. Eur Heart J 2009;30:2631. [3] Costantino G, Perego F, Dipaola F, et al. Short and long-term prognosis of syncope. Risk factors and role of Hospital Admission. Results from the STePS study. J Am Coll Cardiol 2008;51:276. [4] Quinn J, McDermott D. Electrocardiogram findings in emergency department patients with syncope. Acad Emerg Med 2011;18:714. [5] Grossman SA, Fischer C, Lipsitz LA, Mottley L, Sands K, Thompson S, et al. Predicting adverse outcomes in syncope. J Emerg Med 2007;33:233.
Atrial fibrillation related to hyperbaric oxygen therapy To the Editor, We thank Dr Uzun and his colleagues for their interest in our article. It is obvious that the patient had paroxysmal atrial fibrillation (AF) attack twice after hyperbaric oxygen therapy (HBO). We accept Dr Uzun's objection that hyperoxia lasts only several minutes. However, we do not know its effects after several hours on conduction paths. Of course, AF might have been associated with carbon monoxide poisoning, which we could not differentiate. We discussed this possibility in our article. Atrial fibrillation occurred twice after HBO therapy in our patient. After the first dose of HBO therapy, electrocardiography showed AF; after medical cardioversion (amiodarone was administered), the patient's rhythm returned to the normal sinus rhythm. Although the patient' rhythm was sinus before the second dose of HBO therapy, AF was detected immediately after therapy. Normal sinus rhythm was achieved after amiodarone treatment. Because of that all attacks of AF seen after HBO therapy, we thought that AF will be associated with HBO therapy. However, increasing age is a one of risk factor for AF [1-3]. Our patient was 72 years old; also, this factor might have contributed to the occurrence of AF after the HBO therapy. Dr Uzun has recommended cardiologist consultation for heart failure. Our patient was evaluated by a cardiologist, and transthoracic echocardiography was performed. No structural or functional abnormality was found. In the words of Dr Uzun, emergency physicians should not hesitate to refer patients for HBO therapy owing to any arrhythmia concerns but should keep in mind that HBO treatment could contribute to AF. Yours Sincerely Ayhan Saritas MD Department of Emergency Medicine Duzce University School of Medicine 81620 Duzce, Turkey E-mail address:
[email protected] Gokhan Celbek MD Department of Internal Medicine Duzce University School of Medicine 81620 Duzce, Turkey
