2. Acute and chronic dyspnoea

PATHOPHYSIOLOGY OF DYSPNEA

1. Imbalance in Oxygen Demand and Supply

2. Role of Chemoreceptors

3. Mechanical Factors

4. Cardiovascular Contributions

5. Life-threatening Conditions

What can lead to sensations of breathlessness in the body?

• Shortness of breath can be caused by various factors such as physical exertion, anxiety, asthma, heart conditions, lung diseases, high altitude, or obesity.

1. Imbalance in Oxygen Demand and Supply

• Increased Oxygen Demand:

• Decreased Oxygen Delivery:

What are some factors that can contribute to increased oxygen demand in the body?

• Physical activity

• Stress

• Illness or infection

• High altitude

• Exposure to extreme temperatures

How can decreased oxygen delivery occur in the body?

• Decreased oxygen delivery in the body can occur due to factors like low blood volume, reduced hemoglobin levels, lung diseases, or cardiovascular issues.

2. Role of Chemoreceptors

• Central Chemoreceptors

• Peripheral Chemoreceptors:

What are Central Chemoreceptors responsible for detecting?

Changes in the pH of the cerebrospinal fluid influenced by carbon dioxide levels in the blood.

Where are Peripheral Chemoreceptors located?

Carotid bodies at the bifurcation of the carotid arteries and in the aortic arch.

3. Mechanical Factors

• Restrictive Lung Disease:
  Obstructive Lung Disease:

What is the impact of restrictive lung diseases on lung compliance and breathing effort?

Decreases lung compliance, increases work of breathing, and causes dyspnea.

How do obstructive lung diseases affect airflow and exhalation?

Restrict airflow, make exhalation difficult, increase residual lung volume, and cause a sensation of shortness of breath.

Residual Lung Volume:Residual lung volume is the amount of air left in the lungs after maximal exhalation. It helps maintain lung function and prevents lung collapse.

What can cause an imbalance in oxygen demand and supply leading to dyspnea?

Imbalance in oxygen demand and supply can be caused by increased oxygen demand during heavy exercise or metabolic states like hyperthyroidism, and decreased oxygen delivery due to respiratory issues (e.g., asthma) or cardiovascular problems (e.g., heart failure).

4. Cardiovascular Contributions

inadequate cardiac output

How can inadequate cardiac output due to heart diseases contribute to dyspnea?

Inadequate cardiac output due to heart diseases can lead to poor oxygen delivery to tissues, resulting in dyspnea.

5. Life-threatening Conditions

• Conditions like pneumothorax (air in the pleural space) and pulmonary embolism (a clot in the pulmonary arteries)

What are some life-threatening conditions that can acutely impair oxygenation and lead to severe dyspnea?

Life-threatening conditions like pneumothorax (air in the pleural space) and pulmonary embolism (a clot in the pulmonary arteries) can impair oxygenation and cause sudden and severe dyspnea.

TYPES OF DYSPNEA

1. Exertional Dyspnea
2. Resting Dyspnea

3. Paroxysmal Dyspnea

4. Paroxysmal Nocturnal Dyspnea

5. Stenocardia

6. Orthopnea

7. Platypnea

8. Trepopnea

9. Hyperacute Dyspnea

10. Acute Dyspnea

11. Subacute Dyspnea

12. Chronic Dyspnea

13. Severe Dyspnea

14. Imminent Respiratory Failure

What is Exertional Dyspnea?

Shortness of breath that occurs during physical activity.

What are some common conditions associated with Exertional Dyspnea?

Heart and lung diseases, as well as obesity, where the cardiovascular or respiratory system struggles to meet the increased oxygen demand during exertion.

What is Resting Dyspnea?

Breathlessness present even at rest.

In what conditions is Resting Dyspnea typically seen?

Severe heart failure or advanced pneumonia.

What is paroxysmal dyspnea?

Sudden, episodic breathing difficulties.

In which conditions is paroxysmal dyspnea common?

Laryngitis, pertussis, asthma, and COPD.

Pertussis is a highly contagious respiratory disease caused by the bacterium Bordetella pertussis. It is characterized by severe coughing fits, also known as whooping cough.

What is Paroxysmal Nocturnal Dyspnea?

Dyspnea that occurs suddenly during sleep.

What are some conditions associated with Paroxysmal Dyspnea?

Laryngitis, pertussis, asthma, and COPD.

What is stenocardia?

Dyspnea associated with chest pain, typically in diabetic patients where vascular issues are prevalent.

What is orthopnea?

Breathlessness that occurs when lying flat.

In which conditions is orthopnea common?

Heart failure, gastric ulcers, or pneumonia.

What is platypnea?

Worsening dyspnea in the sitting position.

What conditions are platypnea often associated with?

Cardiovascular anomalies like left atrial myxoma, significant pulmonary embolism, or neuromuscular issues like intercostal muscle paralysis.

Left Atrial Myxoma:A left atrial myxoma is a benign tumor that originates in the left atrium of the heart. It is typically a rare condition that can obstruct blood flow and cause symptoms like shortness of breath or chest pain.

What is trepopnea?

Dyspnea that occurs when lying on one side but not the other.

What are the typical causes of trepopnea?

Unilateral lung disease or pleural effusion affecting one lung more than the other.

What is hyperacute dyspnea?

Hyperacute dyspnea is an extremely rapid onset of severe shortness of breath, often associated with life-threatening conditions like pulmonary embolism or severe asthma attacks.

In what situations is hyperacute dyspnea commonly seen?

• Hyperacute dyspnea is commonly seen in situations such as severe asthma attacks, pulmonary embolism, heart failure, and acute exacerbations of chronic obstructive pulmonary disease (COPD).

What is Resting Dyspnea?

Breathlessness present even at rest, typically seen in severe heart failure or advanced pneumonia.

What is Acute Dyspnea?

Breathlessness with onset within hours, examples include pulmonary edema or an acute asthma attack.

What is Exertional Dyspnea?

Shortness of breath that occurs during physical activity.

What is Subacute Dyspnea?

Shortness of breath that develops over days and is associated with conditions like pleural effusion or anemia.

What is chronic dyspnea?

Dyspnea that develops over weeks to months.

What are some conditions in which chronic dyspnea is common?

Chronic conditions such as COPD, interstitial lung diseases (like sarcoidosis or lung fibrosis), or lung cancer.

Interstital lung diseases are a group of disorders that cause inflammation and scarring of the lungs' interstitium. Examples include sarcoidosis and lung fibrosis.

What is Chronic Dyspnea characterized by?

Develops over weeks to months.

What are some conditions in which Chronic Dyspnea is common?

COPD, interstitial lung diseases (like sarcoidosis or lung fibrosis), or lung cancer.

How is Severe Dyspnea characterized?

Significant increase in respiratory effort, fragmented speech, and often diaphoresis.

Diaphoresis is excessive sweating that can be a symptom of various medical conditions, including infections, heart problems, and anxiety disorders.

What does Severe Dyspnea indicate?

Severe respiratory compromise requiring immediate intervention.

What are the hallmarks of imminent respiratory failure?

Extreme fatigue, cyanosis, and impaired mental status

What does imminent respiratory failure suggest?

Very poor oxygenation and impending respiratory collapse

APPROACH TO DYSPNEA

1. Support of Vital Functions

2. Supply Oxygen and Assess Need for Ventilator

3. Rule out Life-threatening Causes

4. Detailed Patient History

5. Physical Examination

6. Laboratory Tests

7. Electrocardiogram (ECG)

8. Chest X-ray

9. Computed Tomography (CT)

10. Transthoracic Echocardiography

11. Spirometry

What are some components of immediate care for supporting vital functions?

Ensuring airway patency, monitoring vital signs, and providing supplemental oxygen.

When might ventilatory support be necessary in supporting vital functions?

Ventilatory support may be necessary in severe cases where the patient struggles to maintain adequate oxygenation or experiences respiratory fatigue.

What is Resting Dyspnea?

Breathlessness present even at rest, typically seen in severe heart failure or advanced pneumonia.

What characterizes Acute Dyspnea?

Onset within hours, examples include pulmonary edema or an acute asthma attack.

Why is it important to supply oxygen and assess the need for a ventilator in dyspneic patients?

Oxygen therapy helps relieve hypoxia, and the decision to escalate to mechanical ventilation depends on the patient’s respiratory effort, blood gas values, and overall clinical condition.

What is the purpose of rapid assessment in a medical emergency?

Identifying life-threatening conditions that require immediate intervention.

Why is gathering a detailed patient history important in a medical evaluation?

To gather information about the onset, duration, associated symptoms, and relevant medical or family history.

What is the purpose of the inspection during a physical examination?

Observing for signs like labored breathing, use of accessory muscles, skin color (cyanosis), and body position.

What does palpation involve during a physical examination?

Checking for any tenderness, masses, or thoracic deformities.

How is percussion used in a physical examination of the lungs?

Assessing for changes in lung sounds that might indicate fluid (dullness) or air (hyperresonance).

What is auscultation in the context of a physical examination?

Listening for abnormal lung sounds such as crackles (indicative of fluid) or wheezing (airway narrowing), and heart murmurs which might suggest valvular issues.

What does an Arterial Blood Gas (ABG) evaluate?

Oxygenation, carbon dioxide levels, and blood acidity.

How do Cardiac Enzymes like Troponin help in diagnosis?

They help in diagnosing myocardial infarction.

What is the purpose of using D-dimer in tests?

It is used to rule out pulmonary embolism, though not specific.

D-dimer tests are used to detect blood clotting disorders or conditions like deep vein thrombosis (DVT) and pulmonary embolism (PE).

What does BNP or pro-BNP indicate?

It indicates heart failure.

What information do Complete Blood Count (CBC) and Basic Metabolic Panel provide?

They provide insight into overall health, infection status, and kidney function.

• Complete Blood Count (CBC): Provides information on red blood cells, white blood cells, and platelets in the blood.

• Basic Metabolic Panel: Provides information on electrolytes, glucose levels, and kidney function.

What does an Electrocardiogram (ECG) detect?

An Electrocardiogram (ECG) detects the electrical activity of the heart, showing the heart's rhythm and any abnormalities like arrhythmias or heart attacks.

What information does a Chest X-ray provide?

• A chest X-ray provides information about the heart, lungs, airways, blood vessels, and bones in the chest area. It can help diagnose conditions like pneumonia, lung cancer, and heart failure.

Why is Computed Tomography (CT) valuable in medical imaging?

Computed Tomography (CT) is valuable in medical imaging due to its ability to provide detailed cross-sectional images of the body, allowing for the visualization of internal structures such as organs, tissues, and bones with great clarity and precision.

What does transthoracic echocardiography assess?

Transthoracic echocardiography assesses the structure and function of the heart using ultrasound waves. It provides information on the heart's chambers, valves, and blood flow.

Why is spirometry useful in diagnosing lung diseases?

• Spirometry measures lung function

• Helps diagnose conditions like asthma, COPD

• Evaluates lung capacity, airflow

• Detects obstructive/restrictive patterns

• Guides treatment and monitoring

DIFFERENTIAL DIAGNOSES

1. Pneumonia

2. COPD Exacerbation

3. Asthma Exacerbation

4. Tension Pneumothorax

5. Spontaneous Pneumothorax

6. Pulmonary Embolism (PE)

7. Acute Chest Syndrome in Sickle Cell Disease

8. Acute Respiratory Distress Syndrome (ARDS)

What are common symptoms of pneumonia?

• Common symptoms of pneumonia include cough, fever, chest pain, shortness of breath, fatigue, and confusion.

What laboratory findings are associated with pneumonia?

• Complete Blood Count (CBC): May show elevated white blood cell count.

• Basic Metabolic Panel: Can reveal electrolyte imbalances or kidney function abnormalities.

What can be observed in chest X-rays of patients with pneumonia

?

• Consolidation or opacity in the affected lung area

• Air bronchograms

• Pleural effusion

• Increased interstitial markings

• Cavitation in some cases

What are the symptoms of a COPD exacerbation?

Increased dyspnea, chronic cough with purulent sputum

COPD stands for Chronic Obstructive Pulmonary Disease. It is a chronic inflammatory lung disease that causes obstructed airflow from the lungs, leading to symptoms like increased dyspnea (shortness of breath) and chronic cough with purulent sputum.

What physical examination findings may be present in a COPD exacerbation?

Tachypnea, diffuse wheezing, decreased breath sounds

What does blood gas analysis often show in a COPD exacerbation?

Respiratory acidosis, hypercapnia, hypoxia

What might X-rays reveal in a patient experiencing a COPD exacerbation?

Hyperinflated lungs, signs of pneumonia, pneumothorax, or pleural effusion

X-rays of a patient experiencing a COPD exacerbation may reveal hyperinflation of the lungs, flattened diaphragms, increased retrosternal air space, and signs of pulmonary hypertension.

What are the symptoms and signs of an asthma exacerbation?

• Symptoms: Shortness of breath, wheezing, coughing, chest tightness.

• Signs: Increased respiratory rate, use of accessory muscles, decreased peak flow.

How are asthma exacerbations often triggered?

Asthma exacerbations are often triggered by allergens, respiratory infections, air pollution, cold air, exercise, and stress.

How is an asthma exacerbation diagnosed?

• Asthma exacerbation is diagnosed based on symptoms like wheezing, coughing, chest tightness, and decreased peak flow readings. Doctors may also use spirometry tests to assess lung function. Treatment includes bronchodilators and steroids.

What are the symptoms of tension pneumothorax?

Severe, sharp chest pain and dyspnea.

• Tension Pneumothorax: A life-threatening condition where air accumulates in the pleural space, causing lung collapse and shifting of organs.

• Types of Pneumothorax: Include primary spontaneous, secondary spontaneous, traumatic, and iatrogenic pneumothorax.

What is a key physical examination finding in tension pneumothorax?

Tracheal deviation away from the affected side.

Why do patients with tension pneumothorax present with tachycardia and hypotension?

Due to reduced venous return to the heart.

Patients with tension pneumothorax present with tachycardia and hypotension due to decreased venous return to the heart caused by increased intrathoracic pressure, leading to decreased cardiac output and subsequent compensatory tachycardia to maintain perfusion.

What are the imaging findings in tension pneumothorax

?

Absent lung markings on the affected side, tracheal and mediastinal shift to the opposite side, and possible pneumomediastinum.

These occur in pneumothorax due to the accumulation of air in the pleural space, causing lung collapse, shifting of mediastinum and trachea, and potential air leakage into the mediastinum.

What are the symptoms of spontaneous pneumothorax?

Sudden onset of unilateral chest pain and dyspnea.

How can spontaneous pneumothorax

be identified through imaging?

X-ray or CT scan shows increased lucency with a visible rim of air between the lung and the chest wall (lung collapse), displaced lung markings, and possibly subcutaneous emphysema.

Explanation:Spontaneous pneumothorax occurs when air enters the pleural space, leading to lung collapse. This results in increased lucency on X-ray/CT due to the presence of air between the lung and chest wall, displaced lung markings, and potential subcutaneous emphysema.

What are the typical symptoms of Pulmonary Embolism (PE)?

Typically presents with pleuritic chest pain, acute onset of dyspnea, hypoxemia, cough, and sometimes hemoptysis.

Symptoms of Pulmonary Embolism:

• Pleuritic chest pain: Due to irritation of the pleura.

• Acute onset of dyspnea: Sudden difficulty in breathing.

• Hypoxemia: Low oxygen levels in the blood.

• Cough: Often dry and non-productive.

• Hemoptysis: Coughing up blood due to lung infarction.

Symptoms of Pulmonary Embolism:

What physical findings may be observed in cases of massive PE?

Hypotension or shock, possible unilateral leg swelling, or a history of deep vein thrombosis (DVT).

• Hypotension or shock: Due to decreased blood flow to the heart.

• Unilateral leg swelling: Result of a blood clot in the leg.

• History of DVT: Increases risk of clot migration to the lungs causing PE.

What is a common laboratory finding in Pulmonary Embolism (PE)?

Elevated D-dimer, which is a marker of clot degradation.

What can elevated troponins and BNP indicate in PE?

Right ventricular strain due to the pulmonary obstruction.

Elevated troponins and BNP in PE can indicate right heart strain or myocardial injury due to increased pressure in the pulmonary circulation.

What might an ECG show in cases of PE?

Normal or sinus tachycardia; in severe cases, signs of right ventricular strain such as a right bundle branch block.

Right Bundle Branch Block (RBBB) is a cardiac conduction disorder where the electrical impulse is delayed or blocked in the right bundle branch of the heart. This can be seen on an electrocardiogram (ECG) as a widened QRS complex.

What is the gold standard imaging modality for diagnosing PE?

CT angiography, showing filling defects in the pulmonary arteries.

How can echocardiography help in diagnosing PE

?

Transthoracic echocardiography (TTE) may show right ventricle hypokinesis with preserved apical movement, indicating strain from pulmonary hypertension.

Echocardiography can show right ventricle strain due to increased pressure in the pulmonary artery, suggesting pulmonary embolism.

What are the symptoms of Acute Chest Syndrome in Sickle Cell Disease?

• Chest pain

• Shortness of breath

• Cough

• Fever

• Wheezing

• Hypoxia

• Tachypnea

• Chest infiltrates on imaging

Acute Chest Syndrome in Sickle Cell Disease is a serious complication characterized by chest pain, fever, cough, and shortness of breath. It can lead to severe respiratory distress and is a leading cause of death in individuals with sickle cell disease.

What are common blood test findings in Acute Chest Syndrome in Sickle Cell Disease

?

• Hemoglobin levels: Decreased

• White blood cell count: Elevated

• Platelet count: Elevated

• Reticulocyte count: Elevated

Acute chest syndrome is a serious complication of sickle cell disease characterized by chest pain, fever, cough, and respiratory distress. It can lead to severe respiratory compromise and is often associated with abnormal blood parameters like decreased hemoglobin levels and elevated white blood cell, platelet, and reticulocyte counts.

What is a hallmark imaging finding in Acute Chest Syndrome in Sickle Cell Disease?

• Pulmonary infiltrate: A hallmark imaging finding in Acute Chest Syndrome in Sickle Cell Disease.

How is Acute Chest Syndrome in Sickle Cell Disease managed?

• Acute Chest Syndrome in Sickle Cell Disease is managed with oxygen therapy, pain management, antibiotics, blood transfusions, and close monitoring for complications.

What are the symptoms of Acute Respiratory Distress Syndrome (ARDS)?

Acute onset of severe hypoxemic respiratory failure, usually within a week of a known clinical insult (e.g., sepsis, trauma, pneumonia).

Acute Respiratory Distress Syndrome (ARDS) is a severe lung condition caused by various factors leading to fluid buildup in the lungs, making breathing difficult. It is characterized by low oxygen levels in the blood and can be life-threatening.

What do patients with ARDS exhibit in terms of clinical features?

Patients exhibit diffuse, bilateral crackles due to non-cardiogenic pulmonary edema caused by increased vascular permeability.

Patients with Acute Respiratory Distress Syndrome (ARDS) exhibit clinical features such as severe shortness of breath, rapid breathing, low oxygen levels, and bilateral infiltrates on chest imaging.

What do arterial blood gases show in patients with ARDS?

Arterial blood gases show marked hypoxemia.

How does the X-ray appear in patients with ARDS?

X-ray displays bilateral patchy, diffuse, or homogeneous lung infiltrates, which do not match the degree of cardiac failure (non-cardiogenic origin).