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dyspnea (shortness of breath {SOB})

The sensation of shortness of breath, difficulty breathing, labored breathing. Alternatively, the uncomfortable awareness of breathing [6]. Classification: Severity grading: (New York Heart Association Classification) - 0. No dyspnea except with strenuous exercise - 1. Slight dyspnea while walking uphill or rapidly on a flat surface. - 2. Dyspnea while walking on a flat surface; unable to keep up with peers, having to stop to catch breath - 3. Dyspnea on walking 100 yards or after a few minutes & having to stop to catch breath - 4. Dyspnea with minimal exertion, i.e. dressing or undressing - 5. Dyspnea at rest. Etiology: 1) heart disease, heart failure a) increased pulmonary capillary pressure b) left atrial hypertension c) increased airway resistance d) decreased lung compliance e) myocardial ischemia, myocardial infarction f) HFrEF & HFpEF [18] 2) obstructive airway disease a) upper airway obstruction - foreign body aspiration b) bronchitis c) asthma d) chronic obstructive pulmonary disease 3) restrictive lung disease/pulmonary parenchymal disease a) pneumonia b) pneumoconiosis c) sarcoidosis 4) pulmonary vascular disease a) pulmonary embolism b) pulmonary hemorrhage c) chronic thromboembolic pulmonary hypertension (CTEPH) 5) pleural effusion 6) chest wall or respiratory muscle disorder a) severe kyphoscoliosis b) paralysis of diaphragm c) respiratory muscle weakness - amyotrophic lateral sclerosis (ALS) 7) other a) anemia b) pregnancy c) drugs d) infection e) psychogenic f) deconditioning g) obesity h) esophageal reflux disease i) advanced cancer (>50-60%, up to 74% with lung cancer) [15] - prevalence increases during the last 6 weeks of life [15] Pathology: 1) generally the result of increased work of breathing 2) other mechanisms a) abnormal activation of respiratory centers b) voluntary hyperventilation c) Cheyne-Stokes respirations d) stimulation of pressure receptors in pulmonary vasculature or right atrium (pulmonary embolus) 3) underlying factors a) hypoxia b) hypercarbia History: - rate of onset, orthopnea, paroxysmal nocturnal dyspnea, effect of physical exertion, history of myocardial infarction, history of syncope, prior episodes of dyspnea, aggravating or relieving factors, edema, weight gain, cough, sputum, fever, nausea, HIV risk factors, history of asthma, occupational exposure Clinical manifestations: 1) response to dyspnea is both physiologic & psychologic a) tachycardia, tachynea b) pain, anxiety, fear 2) heart disease (heart failure) a) dyspnea on exertion b) orthopnea c) paroxysmal nocturnal dyspnea d) dyspnea at rest e) S3 (best predictor of heart failure [12]), S4 f) murmurs g) cardiomegaly h) jugular venous distension - predicts heart failure, but less so than S3 [12] i) hepatomegaly j) peripheral edema - predicts heart failure, but less so than S3 [12] 3) obstructive airway disease a) upper airway obstruction - acute dyspnea with difficulty inhaling - inspiratory stridor - monophonic wheeze - retraction of supraclavicular fossa b) asthma - acute intermittent dyspnea - expiratory wheezes c) chronic obstructive pulmonary disease - slowly progressive exertional dyspnea 4) pulmonary parenchymal disease a) exertional dyspnea early b) tachypnea c) inspiratory rales 5) pulmonary embolism a) multiple discrete episodes of dyspnea with recurrent pumonary embolism b) may be progressive dyspnea without abrupt worsening c) tachypnea d) deep venous thrombosis may or may not be present 6) chest wall or respiratory muscle disorder a) severe kyphoscoliosis - must be severe before respiratory function is compromised b) paralysis of diaphragm - appears normal standing - severe orthopnea Laboratory: - complete blood count [14] - serum TSH [14] - basic metabolic panel [14] - serum BNP useful in distinguishing cardiac from pulmonary source of dyspnea (high serum BNP suggests cardiac source) [8,12,14]* * a serum BNP not likely useful in a patient with a normal echocardiogram Special laboratory: 1) peak flow rate 2) pulmonary function tests - spirometry, lung volumes, DLCO [14] - flow volume loop may distinguish intrathoracic from extrathoracic airway obstruction [14] - useful for evaluating dyspnea in elderly with kyphosis [3] 3) fiberoptic exam of upper airway if suspecting upper airway obstruction - fiberoptic bronchoscopy if suspected foreign body aspiration 4) arterial blood gas 5) electrocardiogram - atrial fibrillation predicts heart failure [12] - ST segment & T wave changes predict heart failure [12] - Q wave predicts heart failure [12] 6) exercise tolerance testing - especially useful in assessment of exertional dyspnea 7) H2FPEF risk score if diastolic heart failure suspected 8) other tests depend on specific etiology Radiology: 1) lateral neck films if suspecting upper airway obstruction 2) chest X-ray - pulmonary edema (LR of heart failure = 11 [12]) - cardiomegaly (LR of heart failure = 7 [12]) - pleural effusion (LR of heart failure = 5 [12]) 3) high-resolution computed tomography (CT) if suspecting: a) interstitial lung disease b) malignant infiltrate c) bronchiectasis d) emphysema 4) CT angiography (spiral CT) detects pulmonary emboli 5) point-of-care ultrasonography can improve diagnostic accuracy in unexplained acute dyspnea [5,17] Management: 1) specific measures for specific etiologies a) corticosteroids particularly useful for bronchospasm b) diuretics may be useful for hypervolemia c) oxygen of benefit if hypoxemic, otherwise not - fans are of benefit for reducing dyspnea in non-hypoxic patients d) systemic opiates for refractory dyspnea in palliative care [5] 2) general measures a) exercise training program - improves physical well-being, endurance & breathlessness without improving lung function or gas exchange b) breathing techniques reduce sense of respiratory effort 1] purse-lipped breathing 2] diaphragmatic breathing c) cool air moving across the face from a fan or open window stimulates the maxillary nerve (cranial nerve V-2) which has a central inhibitory effect on the sensation of breathlessness [3] d) supplemental oxygen 1] benefit in patients with significant dyspnea & only mild hypoxia 2] not beneficial in the absence of hypoxia [5,10] 3] high-flow oxygen relieves dyspnea in palliative care patients [16] e) low-dose opiates reduce sense of breathlessness [5,9,13] 1] oral [7] 2] nebulized/aerosolized morphine a] adjunct for patients already receiving oral opiate b] may be combined with bronchodilator (albuterol) c] no better than nebulized saline [5] f) low-dose benzodiazepines & opiates, alone or in combination, are safe [11] g) anxiolytic agents are generally not effective h) haloperidol reduces sense of breathlessness [5] i) theophylline use to improve diaphragmatic contractility is controversial j) respiratory muscle training of little value 3) pneumonectomy (bilateral)

Related

respiratory distress syndrome (RDS) respiratory urgency

Specific

exertional dyspnea; dyspnea on exertion (DOE) orthopnea paroxysmal nocturnal dyspnea (PND) platypnea trepopnea

General

sign/symptom

References

  1. nlmpubs.nlm.nih.gov/hstat/ahcpr/
  2. Harrison's Principles of Internal Medicine, 13th ed. Companion Handbook, Isselbacher et al (eds), McGraw-Hill NY, 1995, pg 43-44
  3. Geriatric Review Syllabus, 7th edition Parada JT et al (eds) American Geriatrics Society, 2010 - Geriatric Review Syllabus, 11th edition (GRS11) Harper GM, Lyons WL, Potter JF (eds) American Geriatrics Society, 2022
  4. Mayo Internal Medicine Board Review, 1998-99, Prakash UBS (ed) Lippincott-Raven, Philadelphia, 1998, pg 720
  5. Medical Knowledge Self Assessment Program (MKSAP) 11, 15, 16, 17, 18, 19. American College of Physicians, Philadelphia 1998, 2009, 2012, 2015, 2018, 2021. - Medical Knowledge Self Assessment Program (MKSAP) 19 Board Basics. An Enhancement to MKSAP19. American College of Physicians, Philadelphia 2022
  6. Bruera E, Neumann CM. Management of specific symptom complexes in patients receiving palliative care. Canadian Medical Assoc. J (CAMJ):158:1717, 1998
  7. Journal Watch 23(22):176, 2003 Abernathy AP et al, Randomised, double blind, placebo controlled crossover trial of sustained release morphine for the management of refractory dyspnoea. BMJ 327:523, 2003 PMID: 12958109 http://bmj.com/cgi/content/full/327/7414/523
  8. Green SM, Martinez-Rumayor A, Gregory SA, Baggish AL, O'Donoghue ML, Green JA, Lewandrowski KB, Januzzi JL Jr. Clinical uncertainty, diagnostic accuracy, and outcomes in emergency department patients presenting with dyspnea. Arch Intern Med. 2008 Apr 14;168(7):741-8. PMID: 18413557
  9. Mahler DA, Selecky PA, Harrod CG et al American College of Chest Physicians consensus statement on the management of dyspnea in patients with advanced lung or heart disease. Chest. 2010 Mar;137(3):674-91 PMID: 20202949
  10. Abernethy AP, McDonald CF, Frith PA et al Effect of palliative oxygen versus room air in relief of breathlessness in patients with refractory dyspnoea: a double-blind, randomised controlled trial. Lancet. 2010 Sep 4;376(9743):784-93 PMID: 20816546
  11. Ekstrom MP et al. Safety of benzodiazepines and opioids in very severe respiratory disease: National prospective study. BMJ 2014 Jan 30; 348:g445 PMID: 24482539
  12. The NNT: Dyspnea Due to Heart Failure (With Chronic Respiratory Disease) Diagnostics and Likelihood Ratios, Explained http://www.thennt.com/lr/dyspnea-due-to-heart-failure-with-chronic-respiratory-disease/ - The NNT: Dyspnea Due to Heart Failure (Without Chronic Respiratory Disease) Diagnostics and Likelihood Ratios, Explained http://www.thennt.com/lr/dyspnea-due-to-heart-failure-without-chronic-respiratory-disease/ - Wang CS, FitzGerald JM, Schulzer M, Mak E, Ayas NT Does this dyspneic patient in the emergency department have congestive heart failure? JAMA. 2005 Oct 19;294(15):1944-56. PMID: 16234501
  13. Ekstrom MP, Abernethy AP, Currow DC. The management of chronic breathlessness in patients with advanced and terminal illness. BMJ. 2015. 349:g7617 PMID: 25556037
  14. Fein A, Morante JE, Shah AM Diagnostic Errors in Patients With Pulmonary Symptoms. Medscape. June 15, 2017 http://www.medscape.com/slideshow/diagnostic-errors-pulmonary-symptoms-6008747
  15. Medscape Medical News Dyspnea in Advanced Cancer: 'Dying Long Before Death' Medscape - Nov 29, 2017. https://www.medscape.com/viewarticle/889326
  16. Ruangsomboon O, Dorongthom T, Chakorn T et al. High-flow nasal cannula versus conventional oxygen therapy in relieving dyspnea in emergency palliative patients with do-not-intubate status: A randomized crossover study. Ann Emerg Med 2019 Dec 18; PMID: 31864728 Free Article https://www.annemergmed.com/article/S0196-0644(19)31227-2/fulltext
  17. Gartlehner G et al. Point-of-care ultrasonography in patients with acute dyspnea: An evidence report for a clinical practice guideline by the American College of Physicians. Ann Intern Med 2021 Apr 27; [e-pub]. PMID: 33900798 https://www.acpjournals.org/doi/10.7326/M20-5504 - Qaseem A, Etxeandia-Ikobaltzeta I, Mustafa RA et al. Appropriate use of point-of-care ultrasonography in patients with acute dyspnea in emergency department or inpatient settings: A clinical guideline from the American College of Physicians. Ann Intern Med 2021 Apr 27; [e-pub]. PMID: 33900792 Free article https://www.acpjournals.org/doi/10.7326/M20-7844
  18. Reddy YNV et al. Diagnosis of heart failure with preserved ejection fraction among patients with unexplained dyspnea. JAMA Cardiol 2022 Sep; 7:891. PMID: 35830183 PMCID: PMC9280610 (available on 2023-07-13) https://jamanetwork.com/journals/jamacardiology/fullarticle/2793877