Approach to Dyspnoea

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Approach to Dyspnoea

• Prof R Morar

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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)

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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 individuals perception of breathlessness

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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
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Outline

• Overview basic mechanisms of dyspnoea
• Disease states
• Clinical evaluation
• Diagnostic work-up
• Treatment

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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

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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
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Disease States

• Abnormalities of cardiopulmonary function are
  most commonly associated with dyspnoea
• Other organ systems dysfunction can also manifest
  dyspnoea

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Disease States

• Pulmonary
• Cardiovascular
• Upper Airway
• CNS/peripheral
• Renal
• Hepatic

• Endocrine
• Psychogenic
• Miscellaneous
• Anaemia
• Sepsis
• Obesity
• Paediatric

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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

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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

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Disease States

• Upper airway obstruction
• Epiglottitis
• Foreign body
• Croup
• Epstein-Barr virus

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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

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Disease States

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

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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)

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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

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Disease States

• Miscellaneous
• Anaemia
• Sepsis
• Obesity

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Disease States

• Miscellaneous
• Anaemia
• Prominent cause of dyspnoea
• Lower the haemoglobin more pronounced the
  dyspnoea
• Especially in acute anaemia
• Dyspnoea blunted in chronic anaemia

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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)

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Disease States

• Miscellaneous
• Obesity
• Unfit and increased effort
• Coronary artery disease
• Hypertension and left ventricular dysfunction
• Restrictive lungs

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Disease States

• Paediatric
• Bronchiolitis
• Croup
• Epiglottitis
• Foreign body aspiration
• Myocarditis
• DKA

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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

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History

• Determine onset, duration, and occurrence at rest
  or exertion
• Activities and body positions that provoke
  dyspnoea
• Occupational

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History

• Cardiorespiratory 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

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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

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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
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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)
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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
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Clinical Evaluation

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

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Disease States

• Pulmonary
• Cardiovascular
• Upper Airway
• Nervous system
• Renal
• Hepatic

• Endocrine
• Psychogenic
• Miscellaneous
• Anaemia
• Sepsis
• Obesity
• Paediatric

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Examination

• General 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

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Examination

• General Appearance and Vital Signs
• Pallor
• Clubbing
• Cyanosis
• Oedema
• Mental status

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Examination

• Respiratory
• Inspection
• Palpate the chest for subcutaneous emphysema and
  crepitus
• Hyperresonance and tracheal deviation
• Stony dullness
• Absent breath sounds
• Bronchial breathing / amphoric breathing
• Wheezes
• Crackles

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Examination

• Cardiovascular
• 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

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Examination

• Neck
• Raised JVP - congestive heart failure, cardiac
  tamponade, cor pulmonale
• Thyroid - congestive heart failure may result
  from hyperthyroidism or hypothyroidism
• Auscultate for stridor

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Examination

• Abdominal Examination
• Tender hepatomegaly and ascites
• Hepatojugular reflux
• Liver disease - cirrhosis
• Renal disease - enlarged kidneys, uraemic frost,
  pallor and HT

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Examination

• Extremities
• Deep venous thrombosis
• Neurological examination
• Higher functions
• Motor - proximal weakness
• Neuromuscular disorders
• Muscle diseases
• Fasciculations
• Endocrine
• Thyrotoxicosis or myxoedema

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Physical Examination Findings
Findings Possible diagnosis
Wheezing, 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
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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
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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

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Special Investigations

• Pulse oximetry
• Liver and kidney function tests
• Thyroid functions
• Full lung function tests
• Echocardiogram
• Formal exercise test

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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 -
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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 -
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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

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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

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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

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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

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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

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Summary of Evaluation
History and Examination Evidence of cardiopulmonary or other disease
FBC, CXR, ECG, Spirometry Asthma, COPD, Chronic HF, cardiomegaly, HT, Anaemia
UE, Liver Function tests Liver or Renal Disease
Full LFTs, Echocardiogram Restrictive lung disease, valvular heart disease, LV dysfunction
Exercise Test Occult coronary artery disease, asthma
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Conclusion

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