Approach to Dyspnoea

Prof R Morar

Introduction• Dyspnoea, breathlessness or inadequate breathing is accompanied

by the sensations of running out of air and not being able to breathe fast or deeply enough

• The sensations are similar to that of thirst or hunger (an unignorable feeling of needing something)

Introduction

• Various disease states can produce dyspnoea in different ways

• Perception of dyspnoea can vary greatly among individuals

• Assessment of dyspnoea must balance the concepts of physiologic work and ventilatory demand with the individual’s perception of breathlessness

Descriptions for Dyspnoea in Different Conditions

Rapid breathing Chronic heart failure

Incomplete exhalation Asthma

Shallow breathing Restrictive lung diseases

Increased work/effort COPD, interstitial lung disease, neuromuscular disease, chest wall diseases

Suffocation Chronic heart failure

Air hunger COPD, chronic heart failure, sighing dyspnoea

Tight chest Asthma

Heavy Breathing Asthma

Outline

• Overview basic mechanisms of dyspnoea

• Disease states

• Clinical evaluation

• Diagnostic work-up

• Treatment

Basic Mechanisms• The physiologic system that regulates ventilation is extraordinarily

complex

• Receptors in the airways, lung parenchyma, respiratory muscles and chemoreceptors provide sensory feedback via vagal, phrenic and intercostal nerves to the spinal cord, medulla and higher centres

Basic Mechanisms

Mechanoreceptors respiratory muscles

Hypoxia carotid and aortic bodies

Airflow airway and parenchymal receptors

Changes in pCO2/pH medullary center

Irritants airway and parenchymal receptors

Medullary centre afferent input and efferent output

Cortical function sense of effort

Disease States

• Abnormalities of cardiopulmonary function are most commonly associated with dyspnoea

• Other organ systems dysfunction can also manifest dyspnoea

Disease States

• Pulmonary

• Cardiovascular

• Upper Airway

• CNS/peripheral

• Renal

• Hepatic

• Endocrine

• Psychogenic

• Miscellaneous• Anaemia• Sepsis• Obesity

• Paediatric

Disease States

Pulmonary

• Parenchymal lung disease - pneumonia, restrictive lung disease, metastatic

• Airways disease - COPD, asthma

• Pulmonary vascular disease - pulmonary embolic disease

• Pleural - pneumothorax, pleural effusion

• Pulmonary oedema

• Gastroesophageal reflux disease with aspiration

Disease States

Cardiovascular

• Congestive heart failure and pulmonary edema (anemia or pulmonary embolism)

• Coronary artery disease - acute myocardial infarction

• Arrhythmia

• Pericarditis and pericardial effusion

• Valvular disease - mitral stenosis or atrial septal defect

Disease States

Upper airway obstruction

• Epiglottitis

• Foreign body

• Croup

• Epstein-Barr virus

Disease States

Neuromuscular

• Neuromuscular disease is a well known cause of dyspnoea

• Amyotrophic lateral sclerosis

• Disease of the peripheral nerves - Guillain-Barré

• Neuromuscular junction - myasthenia gravis

• Muscle disease - muscular dystrophies, polymyositis

• Severe weight loss from malnutrition, malignancy or chronic disease (weak muscles)

• Pain

• Aspirin overdose or paracetamol overdose

Disease States

Renal

• Renal disease leads to dyspnoea from acidosis, anemia and fluid/volume overload

Disease States

Hepatic

• Chronic liver disease patients often complain of dyspnoea

• Mechanism of dyspnoea obscure

• One particular cause can be small arteriovenous shunts at the lung bases

• This condition is classically associated with breathlessness and oxyhaemoglobin desaturation on assuming the upright position as when arising from bed in the morning (platypnoea)

Disease States

Endocrine

• Hyperthyroidism, can be associated with dyspnoea

– In this setting the sensation is probably related to the hypermetabolic state associated with thyroid over-activity

– In the late stage dyspnoea can be associated with high-output cardiac failure

• Metabolic acidosis e.g. diabetic ketoacidosis

Disease States

Miscellaneous

• Anaemia

• Sepsis

• Obesity

Disease States

Miscellaneous

Anaemia

• Prominent cause of dyspnoea

• Lower the haemoglobin more pronounced the dyspnoea

• Especially in acute anaemia

• Dyspnoea blunted in chronic anaemia

Disease States

Miscellaneous

Sepsis

• Early sepsis / bacteraemia associated with hyperventilation

• Hyperventilation and dyspnoea may be presenting feature

• Cause may be multifactorial (acidosis, tissue ischemia and lactic acidosis, direct effect on the brainstem respiratory centre and carotid bodies by various mediators)

Disease States

Miscellaneous

Obesity

• Unfit and increased effort

• Coronary artery disease

• Hypertension and left ventricular dysfunction

• Restrictive lungs

Disease States

Paediatric

• Bronchiolitis

• Croup

• Epiglottitis

• Foreign body aspiration

• Myocarditis

• DKA

Disease States

Psychogenic

• Panic attacks

• Hyperventilation– Patients exhibit extreme anxiety with concurrent symptoms of

hyperventilation including visual complaints, dizziness, near-syncope and perioral and finger tingling and numbness

• Sighing dyspnoea– inability to take a deep satisfying breath at rest

• Pain

• Anxiety

History

• Determine onset, duration, and occurrence at rest or exertion

• Activities and body positions that provoke dyspnoea

• Occupational

HistoryCardiorespiratory Symptoms

• Chest pain - pleural or coronary disease), AMI

• Pleuritic chest pain - pericarditis, pneumonia, pulmonary embolism, pneumothorax (pneumothorax - traumatic, decompression, spontaneous, catamenial), pleuritis and pleural effusion

• Sudden shortness of breath at rest is suggestive of pulmonary embolism or pneumothorax

• Cough - asthma, COPD, pneumonia, parenchymal lung disease

• Change in the character of sputum – infection

• Sore throat - epiglottitis

History• Cardiac failure symptoms

– Orthopnoea, PND, pedal oedema– Angina and IHD and LV dysfunction

• Drugs - -blockers, eye drops or poisoning

• Psychogenic - hyperventilation syndrome, anxiety

• Smoking

Severity Scale of Dyspnoea - ATS

Grade Degree Characteristics

0 None Only with strenuous activity

1 Slight When hurrying on level ground or climbing a slight incline

2 Moderate Needs to walk more slowly than others of the same age or has to stop for breath when walking at own pace on level ground

3 Severe Stops for breath after 100 metres or after a few minutes

4 Very severe Housebound or dyspnoea when dressing or undressing

Questions in Evaluation of Dyspnoea

Question Probable Pathophysiology

Associated only with exertion? Heart failure, restrictive or obstructive lung disease

Associated with exertion and occurs at night? Cough and wheeze?

Asthma or heart failure

Associated with exertion, chest, arm or neck discomfort and concurrent nausea or sweating?

Angina pectoris

Worse when assuming upright position? Liver disease with arteriovenous shunts at the lung bases (platypnoea)

Present in the lateral decubitus position? Unilateral lung or pleural disease (trepopnoea)

Fast onset when supine, relieved by lateral or upright positioning?

Bilateral phrenic nerve dysfunction

Occurring within minutes or hours of becoming recumbent?

Heart failure (orthopnoea)

Clues to the Diagnosis of Dyspnoea

Symptoms in the history Possible diagnosis

Cough Asthma, COPD, pneumonia

Severe sore throat Epiglottitis

Pleuritic chest pain Pericarditis, pulmonary embolism, pneumothorax, pneumonia, pleural effusion

Orthopnoea, nocturnal paroxysmal dyspnoea, oedema

Congestive heart failure

Tobacco use COPD, congestive heart failure, pulmonary embolism

Indigestion Gastroesophageal reflux disease, aspiration

Barking cough Croup

Clinical Evaluation

Examination

• Organ systems mentioned, with meticulous attention to the respiratory and cardiovascular systems

Disease States• Pulmonary

• Cardiovascular

• Upper Airway

• Nervous system

• Renal

• Hepatic

• Endocrine

• Psychogenic

• Miscellaneous• Anaemia• Sepsis• Obesity

• Paediatric

ExaminationGeneral Appearance and Vital Signs

• To determine the severity of dyspnoea, carefully observe respiratory effort and rate, use of accessory muscles, mental status, and ability to speak in full sentences

• Pulsus paradoxus

• Stridor

• Temperature

• Pulse rate, rhythm and character

• BP

Examination

General Appearance and Vital Signs

• Pallor

• Clubbing

• Cyanosis

• Oedema

• Mental status

ExaminationRespiratory

• Inspection

• Palpate the chest for subcutaneous emphysema and crepitus

• Hyperresonance and tracheal deviation

• Stony dullness

• Absent breath sounds

• Bronchial breathing / amphoric breathing

• Wheezes

• Crackles

ExaminationCardiovascular

• Displaced apex beat and character

• Parasternal heave

• An S3 gallop suggests a left ventricular systolic dysfunction in congestive heart failure

• An S4 gallop suggests left ventricular dysfunction or ischemia

• Loud P2 - pulmonary hypertension or cor pulmonale

• Murmurs can be an indirect sign of congestive heart failure

• Distant heart sounds can point to pericardial effusion and cardiac tamponade

• Pericardial friction rub

Examination

Neck

• Raised JVP - congestive heart failure, cardiac tamponade, cor pulmonale

• Thyroid - congestive heart failure may result from hyperthyroidism or hypothyroidism

• Auscultate for stridor

Examination

Abdominal Examination

• Tender hepatomegaly and ascites

• Hepatojugular reflux

• Liver disease - cirrhosis

• Renal disease - enlarged kidneys, uraemic frost, pallor and HT

Examination

Extremities• Deep venous thrombosis

Neurological examination• Higher functions• Motor - proximal weakness• Neuromuscular disorders• Muscle diseases• Fasciculations

Endocrine• Thyrotoxicosis or myxoedema

Physical Examination Findings

Findings Possible diagnosisWheezing, pulsus paradoxus, accessory muscle use

Acute asthma, COPD exacerbation

Wheezing, barrel chest, decreased breath sounds

COPD exacerbation

Fever, crackles, increased fremitus Pneumonia

Oedema, neck vein distension, S3 or S4 hepatojugular reflux, murmurs, crackles, hypertension, wheezing

Congestive heart failure, pulmonary oedema

Wheezing, friction rub, lower extremity swelling

Pulmonary embolism

Absent breath sounds, hyperresonance

Pneumothorax

Physical Examination Findings

Findings Possible diagnosis

Inspiratory stridor, wheezes, retractions

Croup

Stridor, drooling, fever Epiglottitis

Stridor, wheezing, persistent pneumonia

Foreign body aspiration

Wheezing, flaring, intercostal retractions, apnea

Bronchiolitis

Sighing Hyperventilation

Special Investigations• Chest x-ray PA and lateral

– Lateral neck radiographs (stridor or upper airway obstruction)

• ECG - ischemia, LVH, arrhythmia, troponin-T, enzymes• Spirometry - asthma or COPD• Full blood count - infection or anemia

• d-Dimer - pulmonary embolism• V/Q scan and or spiral computed tomography, pulmonary

angiography• Bilateral venous doppler

Special Investigations

• Pulse oximetry

• Liver and kidney function tests

• Thyroid functions

• Full lung function tests

• Echocardiogram

• Formal exercise test

Diagnostic Evaluation in Dyspnoea

Possible diagnosis

Radiography Pulse oximetry or spirometry

Other tests

Acute asthma, COPD exacerbation

Hyperinflated lungs Decreased O2 sat, decreased PEFR and FEV1

-

Pneumonia Infiltrates, effusion, consolidation

Decreased or normal O2 sat

Normal or high WCC

Congestive heart failure

Interstitial edema, effusion, cardiomegaly

Decreased O2 sat LVH, ischemia, or arrhythmia on ECG; low Hb

Pulmonary embolism

Normal, atelectasis, pleural effusion, wedge-shaped density

Decreased O2 sat RBBB on ECG; tachycardia

Pneumothorax Lung atelectasis, mediastinal shift

Decreased O2 sat -

Diagnostic Evaluation in Dyspnoea

Possible diagnosis

Radiography Pulse oximetry or spirometry

Other tests

Croup Subglottic narrowing by PA plain film or CT

Decreased or normal O2 sat

-

Epiglottitis Enlarged epiglottis Decreased or normal O2 sat

High WCC

Foreign body aspiration

Visualized foreign body, air trapping, hyperinflation

Decreased or normal O2 sat

Normal or high WCC

Bronchiolitis Hyperinflation, atelectasis

Decreased or normal O2 sat

Normal WCC; RSV swab

Hyperventilation Normal Normal -

Treatment• Depends on the specific diagnosis

Acute problem

• Upper airway obstruction or stridor - remove foreign body• Administer oxygen• Consider intubation if patient gasping, apnoeic, or non responsive,

following advanced cardiac life support• Intravenous line access and start administration of fluids and drugs• Needle/tube thoracentesis in patients with tension pneumothorax• Administer nebulized bronchodilator if bronchospasm• Administer IV furosemide if pulmonary edema• Electrocardioversion if unstable arrhythmia

Treatment• Treatment aimed at the underlying cause

• Cardiac failure

• Lung disease

• Severe restrictive lung disease as manifested by pulmonary fibrosis or neuromuscular abnormality poses a particularly difficult problem

• In these cases the complaint is often permanent and debilitating

• The most effective treatment of dyspnoea in cases of far-advanced pulmonary fibrosis is single lung transplantation

• In advanced emphysema lung volume reduction surgery has been tried to relieve dyspnoea by reducing FRC, which reduces the work of breathing by improving the mechanical function of the lungs and diaphragm

Treatment

• Opiates and benzodiazepines have been tried in intractable dyspnoea especially malignant disease

• Anecdotal reports indicate some short-term value

• Clinical trials failed to confirm long-term benefit

• Some studies have demonstrated deleterious events

When to Refer• Many patients with dyspnoea can be evaluated and treated without

referral to a specialist

• Unexplained dyspnoea after routine evaluation usually warrants referral

• When full pulmonary function testing or echocardiography or cardiopulmonary exercise testing required warrants referral

Medico-Legal Considerations

• Acute dyspnoea can be associated with life-threatening diseases such as pulmonary embolism and myocardial infarction

• Failure to promptly and accurately pursue these diagnoses in patients with unexplained dyspnoea can lead to untimely deaths and subsequent lawsuits

Summary of Evaluation

History and ExaminationHistory and Examination Evidence of cardiopulmonary or Evidence of cardiopulmonary or other diseaseother disease

FBC, CXR, ECG, Spirometry Asthma, COPD, Chronic HF, cardiomegaly, HT, Anaemia

U&E, Liver Function tests Liver or Renal Disease

Full LFT’s, Echocardiogram Restrictive lung disease, valvular heart disease, LV dysfunction

Exercise Test Occult coronary artery disease, asthma

Conclusion

An approach to dyspnoea requires:

• Stepwise approach• Beginning with a careful medical history• Physical examination• Appropriate investigations• Specific diagnosis• Treat condition• Refer