approach to dyspnoea / shortness of breath

subjective experience of breathing discomfort that consistes of qualitatively distinct sensations that vary in intensity. the experience derives from interactions among multiple physiological, psychological, social and environmental factors and may induce secondary physiological and behavioral responses

1. Approach to Dyspnoea Moderator – Dr Saurabh Agarwal Professor Department Of Internal Medicine Presented by – Dr Ambika Rai JR 1 Medicine

2. Definition “Subjective experience of breathing discomfort that consists of qualitatively distinct sensations that vary in intensity. The experience derives from interactions among multiple physiological, psychological, social, and environmental factors and may induce secondary physiological and behavioral responses.” American thoracic society

3. Epidemiology One-half of inpatient and one-quarter of ambulatory patients experience dyspnoea . Prevalence 9 – 13 % Increase to as high as 37 % of adults aged >70 year.

4. Mechanism underlying dyspnoea

5. Assessing dyspnoea

6. Differential diagnosis

7. CAUSES OF DYSPNEA A)Pulmonary causes B)Pulmonary and Cardiac causes C)Cardiac causes D)Others

8. A)Pulmonary causes Airway diseases Parenchymal diseases Chest wall diseases

9. 1)Airway diseases e.g. Asthma ,COPD and upper airway obstruction Initial diagnostic studies (and possible findings)- peak flow (reduced); CXR (hyperinflation, loss of lung parenchyma in COPD) ;CT and upper airway examination for upper airway obstruction

10. 2)Parenchymal diseases Interstitial lung disease Initial diagnostic studies ( and possible findings)- spirometry and lung volumes(restrictive ventilatory defect);CXR and chest CT(interstitial lung disease)

11. 3)Chest wall disease Kyphoscoliosis Neuromuscular weakness Initial diagnostic studies(and possible findings) – spirometry and lung volumes (restrictive ventilatory defect);MIP( maximum inspiratory pressure) and MEPs (maximum expiratory pressure)(reduced in NM weakness)

12. B)Pulmonary and cardiac causes Pulmonary hypertension Initial diagnostic studies(and possible findings) – Diffusion capacity (reduced); ECG; ECHO (to evaluate pulmonary artery pressure)

13. C)Cardiac causes Coronary artery disease Cardiomyopathy Constrictive pericarditis Cardiac tamponade Initial diagnostic studies(and possible findings) – consider BNP (brain natriuretic peptide) testing,especially in the acute setting. ECG, ECHO, may need stress testing and/or LHC (left heart catheterization).

14. D)Other causes Anemia Deconditioning Psychological Metabolic disturbances Gastrointestinal ( eg .,Gastro esophageal reflux disease, aspiration pneumonitis) Initial diagnostic studies (and possible findings) - Hematocrit for anemia ; laboratory studies (e.g., metabolic panel, thyroid hormone testing for metabolic disturbances); consider upper gastrointestinal endoscopy and/or esophageal pH probe testing for GERD and concerns for aspiration; exclude other causes

15. Approach to the patient

16. Approach to patient History Physical examination Chest imaging Laboratory studies Distinguishing Cardiovascular from Respiratory system dyspnoea

17. History Should be in his/her own words, what the discomfort feel like, Effect of infection, position, environmental stimuli. eg symptoms of chest tightness might suggest bronchoconstriction, inability to take deep breath may correlate with dynamic hyperinflation of COPD. Orthopnoea is a common indicator of CHF, mechanical impairment of diaphragm associated with obesity, asthma triggered by esophageal reflux, nocturnal dyspnoea suggests Asthma or CHF. Acute intermittent episode may reflect episodes of myocardial ischaemia , bronchospasm, pulmonary embolism. while chronic persistent dyspnoea Is more typical of COPD ,interstitial lung disease and chronic thromboembolism. Platypnoea – left atrial myxoma and hepatopulmonary syndrome

18. Physical examination Pallor, cyanosis, Cirrhosis(spider angiomata , gynaecomastia ) Clubbing(Interstitial pulmonary fibrosis and bronchiectasis) Joint swelling or deformities a/w Reynauds changes may be indicative of collagen vascular process Examination of chest symmetry of movement percussion (dullness is indicative of pleural effusion, resonance is a sign of pneumothorax and emphysema). Auscultation –wheezes, rhonchi, prolonged expiration and diminished breath sound are clues to the airways; rales suggests interstitial edema or fibrosis)

19. Examination of chest symmetry of movement percussion (dullness is indicative of pleural effusion, resonance is a sign of pneumothorax and emphysema). Auscultation –wheezes, rhonchi, prolonged expiration and diminished breath sound are clues to the airways; rales suggests interstitial edema or fibrosis)

20. Cardiac Examination Should focus on signs of elevated right heart pressures (jugular venous distension, edema,accentuated pulmonic component of second heart sound) Left ventricular dysfunction(s3 and s4 gallops) Valvular disease(murmurs)

21. Abdominal examination With patient in supine position – paradoxical movement of abdomen and repiratory distress. Inward motion during inspiration is a sign of diaphragmatic weakness, and rounding of abdomen during exhalation is suggestive of pulmonary edema

22. Patient should be asked to walk under observation with oximetry in order to reproduce symptoms. Patient should be examined during and at the end of exercise for new findings that were not present at rest( eg. , presence of wheezing) and for changes in oxygen saturation.

23. Chest imaging Chest radiograph Hyperinflation – s/o obstructive lung disease Low lung volume – s/o interstitial edema or fibrosis,diaphragmatic dysfunction or impaired chest wall motion. Pulmonary parenchyma should be examined for e/o interstitial disease, infiltrate and emphysema. Prominent pulmonary vasculature in upper zone indicates pulmonary venous hypertension while enlarged central pulmonary arteries may suggest pulmonary arterial hypertension. Enlarged cardiac silhouette - dilated cardiomyopathy or valvular disease

24. Chest imaging ... contd Bilateral pleural effusion – CHF and collagen vascular disease Unilateral effusion- carcinoma and pulmonary embolism but may also occur in heart failure or in parapneumnic effusion. CT generally reserved for further evaluation of lung parenchyma(interstitial lung diseases) and possible pulmonary embolism

25. Laboratory studies Hematocrit, basic metabolic panel(Glucose, calcium, BUN, creatinine, sodium, potassium, bicarbonate and chloride) , ABG. ECG Echocardiography Spirometry Bronchoprovocation test/home peak flow monitoring

26. Distinguishing cardiovascular from respiratory system dyspnoea CPET ( Cardiopulmonary Exercise Test) BNP (Brain Natriuretic Peptide)

27. Treatment The first goal is to correct the underlying condition(s) driving dyspnea and address potentially reversible causes with appropriate treatment for the particular condition. Supplemental O2should be administered if the resting O2 saturation is ≤88% or if the patient’s saturation drops to these levels with activity or sleep. In particular, for patients with COPD, supplemental oxygen for those with hypoxemia has been shown to improve mortality, and pulmonary rehabilitation programs (including some community-based exercise programs such as yoga and Tai Chi) have demonstrated positive effects on dyspnea, exercise capacity, and rates of hospitalization Opioids have been shown to reduce symptoms of dyspnea, largely through reducing air hunger, thus likely suppressing respiratory drive and influencing cortical activity. However, opioids should be considered for each patient individually based on the risk-benefit profile in regard to the effects of respiratory depression.