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a substantial gradient in alcohol intake according to nut consumption could overcome the assumption for a strong unmeasured confounder in the array-approach sensitivity analysis (Table S6 in the Supplementary Appendix), which accounted for a maximal difference in prevalence of 40 percentage points between participants who ate nuts seven or more times per week and those who never ate nuts. Factors such as income level and the pattern of nut consumption (e.g., socially related consumption) should have been studied and, furthermore, adjusted for in the models. Eran Kopel, M.D., M.P.H. Shaye Kivity, M.D. Yechezkel Sidi, M.D. Chaim Sheba Medical Center Tel Hashomer, Israel [email protected] No potential conflict of interest relevant to this letter was reported. 1. Stringhini S, Sabia S, Shipley M, et al. Association of socio-

economic position with health behaviors and mortality. JAMA 2010;303:1159-66. DOI: 10.1056/NEJMc1315777

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similar results. Hazard ratios for death among participants who ate nuts seven or more times per week, as compared with those who did not eat nuts, were 0.79 in the cohort of women (95% confidence interval [CI], 0.69 to 0.91), 0.81 in the cohort of men (95% CI, 0.73 to 0.90), and 0.80 in the pooled cohort (95% CI, 0.74 to 0.87). As suggested by Kopel et al., we performed an additional analysis adjusting for alcohol intake as a continuous variable and found similar results. Hazard ratios for death among participants who ate nuts seven or more times per week, as compared with those who did not eat nuts, were 0.78 in the cohort of women (95% CI, 0.68 to 0.90), 0.78 in the cohort of men (95% CI, 0.71 to 0.87), and 0.78 in the pooled cohort (95% CI, 0.72 to 0.85). Although socioeconomic status is related to mortality, the study participants, being nurses and health professionals, are relatively homogeneous. Ying Bao, M.D., Sc.D. Bernard A. Rosner, Ph.D. Brigham and Women’s Hospital Boston, MA [email protected]

The authors and a colleague reply: We agree Charles S. Fuchs, M.D., M.P.H. with Elin that nuts are rich in magnesium, a fact Dana–Farber Cancer Institute that may contribute to the observed inverse asso- Boston, MA Dr. Rosner reports no potential conflict of interest relevant to ciation between nut consumption and total mor- this letter. Since publication of their article, Drs. Bao and Fuchs tality. We performed an additional analysis ad- report no further potential conflict of interest. justing for total magnesium intake and found DOI: 10.1056/NEJMc1315777

Laryngeal Mask Airway in Medical Emergencies To the Editor: In their Video in Clinical Medicine, Lighthall et al. (Nov. 14 issue)1 illuminate the utility of the laryngeal mask airway (LMA) in airway management during cardiopulmonary arrest. However, the existing data supporting the emergency application of this and other supraglottic airway devices (e.g., the laryngeal tube) are limited and conflicting. Lighthall et al. state that LMA placement is usually successful on the first attempt, but a meta-analysis showed that the success rate for prehospital LMA insertion was only 85%.2 Numerous observational studies have not shown reliable differences in outcomes for cardiopulmonary arrest between the use of supraglottic airway devices and tracheal intubation, and the use of any advanced airway device has not been shown to be superior to bag-and882

mask ventilation alone.3-5 The most effective approach to airway management probably varies according to the characteristics of the patients, the clinical circumstances, and the airway experience and skills of the rescuer. Prospective, controlled trials would help to clarify the best approaches to emergency airway management, particularly during cardiopulmonary arrest. Henry E. Wang, M.D. University of Alabama School of Medicine Birmingham, AL

Clifton W. Callaway, M.D., Ph.D. University of Pittsburgh School of Medicine Pittsburgh, PA

Jasmeet Soar, M.B. Southmead Hospital Bristol, United Kingdom [email protected]

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correspondence Dr. Soar reports being the editor of Resuscitation, the chair of the European Resuscitation Council Advanced Life Support (ALS) Working Group, the cochair of the International Liaison Committee on Resuscitation (ILCOR) ALS Task Force, and a steering group member of the Airway Management Feasibility Study (REVIVE-Airways). No other potential conflict of interest relevant to this letter was reported.

No potential conflict of interest relevant to this letter was reported.

1. Lighthall G, Harrison TK, Chu LF. Laryngeal mask airway in

DOI: 10.1056/NEJMc1315505

medical emergencies. N Engl J Med 2013;369(20):e26. 2. Hubble MW, Wilfong DA, Brown LH, Hertelendy A, Benner RW. A meta-analysis of prehospital airway control techniques. II. Alternative airway devices and cricothyrotomy success rates. Prehosp Emerg Care 2010;14:515-30. 3. Hasegawa K, Hiraide A, Chang Y, Brown DF. Association of prehospital advanced airway management with neurologic outcome and survival in patients with out-of-hospital cardiac arrest. JAMA 2013;309:257-66. 4. Wang HE, Szydlo D, Stouffer JA, et al. Endotracheal intubation versus supraglottic airway insertion in out-of-hospital cardiac arrest. Resuscitation 2012;83:1061-6. 5. Kajino K, Iwami T, Kitamura T, et al. Comparison of supraglottic airway versus endotracheal intubation for the pre-hospital treatment of out-of-hospital cardiac arrest. Crit Care 2011; 15:R236. DOI: 10.1056/NEJMc1315505

To the Editor: Lighthall et al. state that after the LMA is connected to a positive-pressure ventilation system, verification of proper LMA placement is achieved through auscultation of breath sounds.1 Unlike the assessment of an endotracheal tube, LMA function is better evaluated by auscultation over the neck rather than the chest.2 However, LMA function is more often assessed by observing the following measures: airway pressure and chest movement with manual ventilation in the prone position, reservoir-bag refill during expiration, auscultation over the neck, cuff-leak pressure, capnography, and expired tidal volume and flow-volume loop.1 Gas exchange and the possibility of obstruction are assessed more appropriately by the latter two techniques. Capnography has recently become the standard for identifying the correct device position. Although clinically significant cardiorespiratory failure during emergencies might limit the efficacy of capnography due to considerably decreased pulmonary perfusion, end-tidal carbon dioxide measures and patterns allow monitoring of not only proper LMA placement but also hemodynamics and the success of resuscitation. Hence, the use of capnography even in emergency conditions should not be overlooked.2 Samad E.J. Golzari, M.D. Ata Mahmoodpoor, F.I.C.M. Tabriz University of Medical Sciences Tabriz, Iran [email protected]

1. Joshi S, Sciacca RR, Solanki DR, Young WL, Mathru MM. A

prospective evaluation of clinical tests for placement of laryngeal mask airways. Anesthesiology 1998;89:1141-6. 2. Morley PT. Monitoring the quality of cardiopulmonary resuscitation. Curr Opin Crit Care 2007;13:261-7.

The authors reply: The nature and role of ventilation during cardiopulmonary resuscitation (CPR) have been revised in recent guidelines and are likely to evolve further. The data cited by Wang et al. are from large prehospital resuscitation registries that suggest better outcomes associated with bag-and-mask ventilation than with LMA. However, retrospective risk adjustments leave open the possibility of confounding by factors such as provider training, order of interventions, and time trade-offs between airway instrumentation and chest compressions administered by a small crew. A variety of studies suggest that mask ventilation is not a default skill one can assume for most responders to an arrest.1,2 Bagand-mask ventilation often requires two providers to be successful, as compared with a single provider who uses LMA.3 In addition, the incidence of gastric regurgitation may be lower if LMA is used as a primary airway before endotracheal intubation, as compared with bag-andmask ventilation.4 The goal of our video was to provide initial instruction in the skill of LMA insertion. The wide use of LMA in hospitals worldwide suggests that learning its placement as a backup or alternative to mask ventilation and tracheal intubation is an important skill. We concur that prospective, controlled trials are needed to address ideal airway management for cardiac arrests both inside and outside the hospital. In response to Golzari and Mahmoodpoor: we agree that waveform capnography may be valuable during LMA placement during CPR. However, its role in the management of arrests with supraglottic airway devices is not well defined.5 We emphasized chest and neck auscultation to assess the success of LMA insertion because it can be done rapidly with a stethoscope without interrupting chest compressions. Flowvolume loops and collapsible bags are not typically available on resuscitation carts and so were not included. We did mention auscultation of air leak as an initial indication of proper placement and seal, as Golzari and Mahmoodpoor suggest.

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LMA placement will produce the greatest benefit if it is applied in the proper clinical context with periodic examination of outcomes and alternatives. Geoffrey Lighthall, M.D., Ph.D. T. Kyle Harrison, M.D. Larry F. Chu, M.D. Stanford University School of Medicine Stanford, CA [email protected] Since publication of their article, the authors report no further potential conflict of interest. 1. Cummins RO, Austin D, Graves JR, Litwin PE, Pierce J. Venti-

lation skills of emergency medical technicians: a teaching challenge for emergency medicine. Ann Emerg Med 1986;15:1187-92.

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2. Elling R, Politis J. An evaluation of emergency medical tech-

nicians’ ability to use manual ventilation devices. Ann Emerg Med 1983;12:765-8. 3. Alexander R, Hodgson P, Lomax D, Bullen C. A comparison of the laryngeal mask airway and Guedel airway, bag and facemask for manual ventilation following formal training. Anaesthesia 1993;48:231-4. 4. Stone BJ, Chantler PJ, Baskett PJ. The incidence of regurgitation during cardiopulmonary resuscitation: a comparison between the bag valve mask and laryngeal mask airway. Resuscitation 1998;38:3-6. 5. Neumar RW, Otto CW, Link MS, et al. Adult advanced cardiovascular life support: 2010 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation 2010;122:Suppl 3:S729-S767. [Erratum, Circulation 2011;123(6):e236.] DOI: 10.1056/NEJMc1315505

Dead Man Walking To the Editor: The American College of Physicians (ACP) agrees with Stillman and Tailor (Nov. 14 issue)1 that we need health care for the millions of Americans placed at greater risk for suffering simply because they lack health insurance. However, the authors didn’t do enough checking before stating that “The American College of Physicians [has] endorsed the principle of universal health care coverage yet [has] generally remained silent during years of political debate.” We have relentlessly advocated for universal health coverage and the Affordable Care Act (ACA). A Web search of our public-policy library (www .acponline.org/advocacy/policies) finds 321 documents since 2008 supporting effective implementation of the ACA. We helped get the ACA through Congress, applauded the Supreme Court decision to uphold it, and developed an action plan for our chapters to urge their states to accept expanded Medicaid; we have also commented on every major rule implementing the program and have spoken out on efforts to delay or defund it. We are diligently working to ensure that the uninsured no longer are at risk for dying owing to a lack of insurance. Molly Cooke, M.D. American College of Physicians San Francisco, CA Dr. Cooke reports being the president of the American College of Physicians. No other potential conflict of interest relevant to this letter was reported.

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The author replies: I am acquainted with the ACP policy library and appreciate its considerable legislative efforts. When I was in private practice, many of my patients believed that physicians uniformly opposed the ACA. Their impression was understandable: although the advocacy of physician organizations was publicly invisible, the U.S. airwaves were clogged with dire predictions by the opposition about death panels, socialism, and patient and physician malcontent. The Obama administration inadequately educated Americans about the ACA, yet few prominent physicians publicly challenged the detractors of the legislation. In short, we allowed untruths to harden, and the leaders of our profession should have been noisier in their activism. Americans most trust health care professionals to educate them about the ACA yet have received their information largely from biased or inadequately informed news media and social networks.1 Although I am aware of the persistent but behind-the-scenes lobbying by the ACP, perhaps a more public and, yes, “vocal” form of advocacy was appropriate. Michael Stillman, M.D. University of Louisville School of Medicine Louisville, KY Since publication of his article, the author reports no further potential conflict of interest. 1. Kaiser Health Tracking Poll: August 2013. Menlo Park, CA:

1. Stillman M, Tailor M. Dead man walking. N Engl J Med

2013;369:1880-1.

Kaiser Family Foundation, 2013 (http://kff.org/health-reform/ poll-finding/kaiser-health-tracking-poll-august-2013).

DOI: 10.1056/NEJMc1315970

DOI: 10.1056/NEJMc1315970

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