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A Dangerous Myth: Does Speaking Imply Breathing?

2020; American College of Physicians; Volume: 173; Issue: 9 Linguagem: Inglês

10.7326/m20-4186

1539-3704

Anica C. Law, Gary E. Weissman, Theodore J. Iwashyna,

Family and Patient Care in Intensive Care Units

Ideas and Opinions3 November 2020A Dangerous Myth: Does Speaking Imply Breathing?FREEAnica C. Law, MD, MS, Gary E. Weissman, MD, MSHP, and Theodore J. Iwashyna, MD, PhD, on behalf of the Pulmonary Critical Care Anti-Racism Working Group*Anica C. Law, MD, MSCenter for Healthcare Delivery Science and Smith Center for Outcomes Research, Beth Israel Deaconess Medical Center, Boston, Massachusetts (A.C.L.)Search for more papers by this author, Gary E. Weissman, MD, MSHPPalliative and Advanced Illness Research Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania (G.E.W.)Search for more papers by this author, and Theodore J. Iwashyna, MD, PhDCenter for Clinical Management Research, VA Ann Arbor Healthcare System, and National Clinician Scholars Program at the University of Michigan, Ann Arbor, Michigan (T.J.I.)Search for more papers by this author, on behalf of the Pulmonary Critical Care Anti-Racism Working Group*Search for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/M20-4186 SectionsAboutVisual AbstractPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail Visual Abstract. Does Speaking Imply Breathing?This article reviews basic respiratory physiology and highlights the clinician's role in discouraging the public from relying on speech as a sign of adequate respiration, especially to propagate injustice or violence. Download figure Download PowerPoint On 25 May 2020, George Floyd pleaded at least 16 times, “I can't breathe.” One officer in attendance nonetheless told bystanders, “He's talking. He's fine” (1, 2). Mayor Hal Marx of Petal, Mississippi, posted on Twitter the following day, “If you can say you can't breathe, you're breathing.” Similar arguments were put forth by New York Representative Peter King and police officials in the wake of Eric Garner's death in 2014 (3, 4). The belief that a person's ability to speak precludes the possibility of suffocation is not true and can have fatal consequences. Although the medical community may suspect that vocalization does not guarantee adequate respiration, they may not be sufficiently familiar with the relevant physiology to allow them to speak with authority. Here, we review basic respiratory physiology and highlight our role as clinicians and scientists in educating the public against relying on speech as a sign of adequate respiration—especially when this medical misconception is used to propagate injustice or violence.The volume of an ordinary breath is approximately 400 to 600 mL. When each breath is inhaled, air first fills the upper airway, trachea, and bronchi; speech is generated here, but no gas exchange takes place in this anatomical dead space. Only air that exceeds the volume of this dead space is conducted to the alveoli for gas exchange. Normal speech only requires approximately 50 mL of gas per syllable—thus, stating “I can't breathe” would require 150 mL of gas (5). Anatomical dead space is typically one third the volume of an ordinary breath. George Floyd could have uttered those syllables repeatedly with small breaths that filled only the trachea and bronchi but brought no air to the alveoli, where actual gas exchange happens.Phonation can occur with exhalation alone in the complete absence of inhalation by using the expiratory reserve volume that remains after a normal tidal breath is exhaled. In contrast, adequate gas exchange to support life requires inhalation as well. A 70-kg adult requires 4 to 5 L of air per minute (at rest) to reach the alveoli, where oxygen and carbon dioxide are exchanged with the blood; light muscular activity requires double that, and a person in extremis may require more than 100 L of air per minute (6). If less air reaches the alveoli, there may be devastating cardiopulmonary consequences, including death.The origin of the pernicious myth that speaking signals adequate breathing is unclear but may be an extrapolation from first aid training for choking. Multiple training sources cite the inability to talk as a sign of choking along with other late signs of respiratory compromise, including dusky skin or loss of consciousness (7). It is true that if you cannot move any air you cannot speak. However, the reverse is not true: You can move enough air to produce sound but not be able to breathe enough to sustain the gas exchange needed to prevent organ damage from hypoxemia. It is therefore not surprising that such a person as George Floyd may have been able to both generate the sentence “I can't breathe” and still experience severe air hunger (that is, dyspnea) and decompensate into a state of respiratory failure.This apparent paradox is also consonant with our experiences as pulmonary and critical care clinicians. We all have taken medical histories and even discussed intubation with patients who had rapidly increasing carbon dioxide levels or decreasing oxygen levels and were clearly in respiratory failure. A colleague recalled her child having the ability to scream “I can't breathe” before losing consciousness from respiratory failure during an asthma exacerbation. As care providers, we are trained to prioritize addressing impairments to breathing and circulation above all else. Doing so includes recognizing earlier signs of respiratory failure, such as an increased respiratory rate, tripoding, or using accessory muscles to breathe. Waiting until a person loses the ability to speak may be too late to prevent catastrophic cardiopulmonary collapse.Air hunger is the most uncomfortable and emotionally distressing quality of dyspnea. It directly activates the insular cortex, a primal sensory area of the brain that responds to such basic survival threats as pain, hunger, and thirst (8). Data from studies of war and torture victims show that the sensation of suffocation is the single strongest predictor of posttraumatic stress disorder and can cause more persistent psychological damage than mock execution with a pistol (9). This finding suggests that clinicians have a fundamental responsibility to serve as advocates for persons who report respiratory distress.The use of incorrect physiologic statements to justify the force leading to the deaths of Eric Garner and George Floyd is unacceptable. According to our oath as clinicians, it is our responsibility to the public to aggressively correct such misconceptions to prevent further deaths. However, as human beings, we emphasize that it does not take medical training to inherently understand the profound danger and inhumanity behind forcibly inducing respiratory distress in another person. The persistent use of malignant platitudes in the face of another person's suffering is disturbing. At best, it represents the thoughtless use of heuristic shortcuts; at worst, it indicates deep gaps in empathy, toxic cognitive biases, or malicious intent. We hope that everyone will join us in advocating that all persons who describe respiratory distress receive immediate, serious attention and treatment.References1. Hill E, Tiefenthäler A, Triebert C, et al. How George Floyd was killed in police custody. The New York Times. 31 May 2020. Accessed at www.nytimes.com/2020/05/31/us/george-floyd-investigation.html on 2 June 2020. Google Scholar2. Culver J. What we know about the death of George Floyd: 4 Minneapolis police officers fired after ‘horrifying' video hits social media. USA Today. Updated 27 May 2020. Accessed at www.usatoday.com/story/news/nation/2020/05/26/george-floyd-minneapolis-police-officers-fired-after-public-backlash/5263193002 on 2 June 2020. Google Scholar3. CBS Interactive. NYPD chokehold victim Eric Garner complicit in own death, union says. 5 December 2014. Accessed at www.cbsnews.com/news/nypd-chokehold-victim-eric-garner-complicit-in-own-death-union-says on 2 June 2020. Google Scholar4. Mccalmont L. Rep. King: health issues led to death. Politico. 4 December 2014. Accessed at www.politico.com/story/2014/12/peter-king-eric-garner-reaction-113319.html on 2 June 2020. Google Scholar5. Hoit JD, Lohmeier HL. Influence of continuous speaking on ventilation. J Speech Lang Hear Res. 2000;43:1240-1251. [PMID: 11063244] CrossrefMedlineGoogle Scholar6. Castro RRT, Lima SP, Sales ARK, et al. Minute-ventilation variability during cardiopulmonary exercise test is higher in sedentary men than in athletes. Arq Bras Cardiol. 2017;109:185-190. [PMID: 28977060] doi:10.5935/abc.20170104 CrossrefMedlineGoogle Scholar7. American Red Cross. Conscious choking. 2011. Accessed at www.redcross.org/content/dam/redcross/atg/PDF_s/ConsciousChokingPoster_EN.pdf on 2 June 2020. Google Scholar8. Banzett RB, Mulnier HE, Murphy K, et al. Breathlessness in humans activates insular cortex. Neuroreport. 2000;11:2117-2120. [PMID: 10923655] CrossrefMedlineGoogle Scholar9. Basoglu M. Waterboarding is severe torture: research findings. Mass Trauma, Mental Health & Human Rights: Metin Basoglu's Blog on War, Torture, and Natural Disasters. 25 December 2012. Accessed at https://metinbasoglu.wordpress.com/2012/12/25/waterboarding-is-severe-torture-research-findings on 3 June 2020. Google Scholar Comments0 CommentsSign In to Submit A Comment David L Keller, MD, FACPAssociate Editor, CCJM29 June 2020 This outstanding article should be disseminated widely This article explains clearly why the ability to speak does NOT prove that adequate ventilation for survival is taking place. This article should be quoted, cited and disseminated as widely as possible at every opportunity by physicians. I believe it can be understood by a bright high school diplomate, as well as medical personnel, and special praises to the authors for that! This article will save lives. Thank you. Renata R. T. Castro, MD, PhD, FACC, FACP João G. Silveira Neto, MD Marco Orsini, MD, PhD Roberta R. T. Castro, PhDCardiologia do Esporte, Rio de Janeiro17 July 2020 Exercise physiology to fight racism: talk test, oxygen consumption, and George Floyd suffocation We read with interest the article by Law et al. recently published in Annals of Internal Medicine(1). The authors clearly explained that someone can still speak even if enough ventilation for survival is not provided. As described by the authors, phonation occurs from the exhalation of air, which can happen by the use of expiratory reserve volume, even if inhalation has not happened. Body tissues require oxygen to keep functioning during rest, and this demand increases during exercise. In fact, oxygen consumption and ventilation increase accordingly to exercise intensity. Training intensity can be monitored by objective (e.g., heart rate) or subjective methods (rate of perceived exertion and Talk Test). Talk Test has been used since the ’90s and correlates the comfort to talk to exercise intensity. Although subjective, Talk Test is useful to advise patients on how to monitor intensity and keep them from training too hard(2). During incremental exercise tests, the point where speech first becomes difficult is correlated to the ventilatory threshold (3, 4). Additionally, exercising above the ventilatory threshold makes speaking uncomfortable (3). Even at maximum efforts, one can still talk in syllables. George Floyd was not exercising or fighting while he was pleading to be unable to breathe. Total lung capacity is around 6L in a man. As inspired air has 21% of oxygen, our lungs usually have 1260 mL of oxygen after a full inspiration. Blood transports oxygen dissolved in plasma and bound to hemoglobin(5). At physiological arterial oxygen pressure (100 mmHg), 100 mL of plasma contains 0.3 ml of oxygen. And 100 mL of blood contains 15 g of hemoglobin, which can bind to 20,1 mL of oxygen. Considering that blood volume accounts for 10% of our body mass, a man weighing 100 kg, as George Floyd, has 10 L of blood with 2,040 mL of oxygen. This can be taken as pure math, but all the previous physiologic statements lead us to the conclusion that George Floyd had 3.300 mL of oxygen at the moment suffocation started. At rest, oxygen consumption is about 3.5 mL/Kg/min(5). As George Floyd weighted 100 Kg, he probably consumed 350 mL of oxygen per minute at rest. There are no studies that evaluated the increase in energy requirements while in such a stressful situation. Still, previous studies concluded that organic stress caused by infection or cancer usually increases body energy requirements by 25-40%(6). If we consider that George Floyd’s energy requirements were increased by 25%, he would probably need 437.5 mL of oxygen per min. Thus 3.300 mL of oxygen would be enough for surviving 7,5 minutes without breathing. A police officer knelt on George Floyd’s neck for nearly eight minutes before he died. Thus, physiology knowledge can explain not only how a man could plead that he was not breathing, but also how he kept alive for nearly eight minutes while a police officer kneeling on his neck blocked ventilation. There were more than seven minutes for the policeman to give up the aggression and let George Floyd breathe again, without dying. We agree with Law et al. that the spread of physiologic statements such as the one in this letter is our responsibility as physicians. Respiratory distress is torturing and can lead to death after several minutes. It is time for us to fight against racism and torture. Author, Article, and Disclosure InformationAffiliations: Center for Healthcare Delivery Science and Smith Center for Outcomes Research, Beth Israel Deaconess Medical Center, Boston, Massachusetts (A.C.L.)Palliative and Advanced Illness Research Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania (G.E.W.)Center for Clinical Management Research, VA Ann Arbor Healthcare System, and National Clinician Scholars Program at the University of Michigan, Ann Arbor, Michigan (T.J.I.)Disclaimer: The views expressed here do not necessarily represent the views of the U.S. government or U.S. Department of Veterans Affairs.Disclosures: Authors have disclosed no conflicts of interest. Forms can be viewed at www.acponline.org/authors/icmje/ConflictOfInterestForms.do?msNum=M20-4186.Corresponding Author: Anica C. Law, MD, MS, 330 Brookline Avenue, Boston, MA 02215; e-mail, [email protected]harvard.edu.Current Author Addresses: Dr. Law: 330 Brookline Avenue, Boston, MA 02215.Dr. Weissman: 423 Guardian Drive, 306 Blockley Hall, Philadelphia, PA 19104.Dr. Iwashyna: 2800 Plymouth Road, NCRC B16 Room 326W (VA CCMR), Ann Arbor, MI 48109.Author Contributions: Conception and design: A.C. Law, G.E. Weissman.Analysis and interpretation of the data: T.J. Iwashyna.Drafting of the article: A.C. Law, G.E. Weissman.Critical revision of the article for important intellectual content: A.C. Law, G.E. Weissman, T.J. Iwashyna.Final approval of the article: A.C. Law, G.E. Weissman, T.J. Iwashyna.Administrative, technical, or logistic support: A.C. Law, G.E. Weissman.This article was published at Annals.org on 25 June 2020.* Members of the Pulmonary Critical Care Anti-Racism Working Group who contributed to this work were Robert B. Banzett, PhD; Robert Dickson, MD; Michael Hess, MPH, RRT, RPFT; Aluko A. Hope, MD; Nida Qadir, MD; and Allan J. Walkey, MD, MSc. PreviousarticleNextarticle Advertisement FiguresReferencesRelatedDetails Metrics Cited byThe Respiratory Foundations of Spoken LanguageRationing, racism and justice: advancing the debate around ‘colourblind’ COVID-19 ventilator allocation 3 November 2020Volume 173, Issue 9Page: 754-755 ePublished: 25 June 2020 Issue Published: 3 November 2020 Copyright & PermissionsCopyright © 2020 by American College of Physicians. All Rights Reserved.PDF downloadLoading ...