HA Medicine I And Gynecology Unit 3 Respiratory Disorders Notes | HA Medicine I And Gynecology Unit 3 Respiratory Disorders Second Year In Health Science (PCL)

HA Medicine I And Gynecology

Unit 3: Respiratory Disorders – Study Notes

Second Year in Health Science (PCL) | Syllabus Based

Introduction to Respiratory Disorders

Respiratory disorders constitute a significant portion of global disease burden, particularly in developing countries like Nepal. This unit covers six major respiratory conditions that are commonly encountered in clinical practice. Understanding their etiology, pathophysiology, clinical features, and management is crucial for healthcare professionals. – HA Medicine I And Gynecology Unit 3 Respiratory Disorders Notes

Clinical Importance: Respiratory diseases account for approximately 10% of all hospital admissions in Nepal. Early recognition and appropriate management can significantly reduce morbidity and mortality.

3.1 Acute Bronchitis

Definition

Acute inflammation of the bronchi, usually caused by infection, leading to cough and sputum production.

Etiology

Viral infection (Influenza, RSV, Rhinovirus) – most common
Bacterial infection (rare)
Smoking and passive smoking
Air pollution, dust, cold air

Pathophysiology

Easy Concept: Infection → inflammation of bronchial mucosa → increased mucus secretion → narrowing of airways → cough and breathing difficulty.

Clinical Features

Main Symptom: Cough (dry at first, then productive of clear/yellow/green mucus)
Low-grade fever, fatigue
Chest discomfort/wheezing
Sore throat, runny nose (if viral cause)
No signs of pneumonia (no high fever, severe shortness of breath, or lung consolidation)

Important: Acute bronchitis is usually viral; antibiotics are not routinely indicated unless bacterial infection is confirmed.

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3.2 Chronic Obstructive Pulmonary Disease (COPD)

Definition

Chronic, progressive lung disease characterized by persistent airflow limitation.

Components

Chronic Bronchitis – chronic cough with sputum for ≥3 months for 2 consecutive years
Emphysema – destruction of alveolar walls leading to air trapping

Etiology

Cigarette Smoking (Major cause in Nepal and worldwide)
Biomass Fuel Exposure (Very important in Nepal – indoor cooking with wood/dung)
Occupational dusts/chemicals
Genetic factor: Alpha-1 Antitrypsin Deficiency (rare)

Management

Smoking cessation – most important intervention
Bronchodilators (short-acting and long-acting)
Inhaled corticosteroids (for severe cases)
Oxygen therapy (for severe hypoxemia)
Pulmonary rehabilitation

3.3 Pleural Effusion

Definition

Accumulation of excess fluid in the pleural space between the parietal and visceral pleura.

Etiology

Tuberculosis (common in Nepal)
Pneumonia (parapneumonic effusion)
Heart failure (transudative effusion)
Malignancy (lung cancer, mesothelioma)
Liver or kidney disease

Light’s Criteria for Exudative Effusion

Pleural fluid is classified as exudate if ANY ONE of the following is present:

Pleural fluid protein / serum protein > 0.5
Pleural fluid LDH / serum LDH > 0.6
Pleural fluid LDH > 2/3 of upper normal serum LDH

Clinical Tip: Diagnostic thoracentesis (pleural tapping) should be performed for new, unexplained pleural effusions to determine the etiology.

3.4 Pneumonia

Definition

Acute infection of the lung parenchyma (alveoli) leading to consolidation and impaired gas exchange.

Classification

By Location	By Anatomy	By Cause
Community-Acquired (CAP)	Lobar (whole lobe)	Bacterial
Hospital-Acquired (HAP)	Bronchopneumonia (patchy)	Viral
		Fungal

Prevention (Vaccines)

Pneumococcal vaccine – recommended for children, elderly, and immunocompromised
Hib vaccine – part of routine childhood immunization
Influenza vaccine – annual vaccination reduces risk of secondary bacterial pneumonia

3.5 Asthma

Definition

Chronic inflammatory airway disease characterized by reversible airflow obstruction, bronchial hyperresponsiveness, and underlying inflammation.

Classification by Severity (Before Treatment)

Severity	Symptoms	Night Symptoms
Intermittent	≤2 days/week	≤2x/month
Mild Persistent	>2 days/week but not daily	3-4x/month
Moderate Persistent	Daily symptoms	>1x/week
Severe Persistent	Throughout the day	Frequent (often 7x/week)

Management Approach

Stepwise Management:

Step 1 (Intermittent): SABA as needed
Step 2 (Mild Persistent): Low-dose ICS + SABA as needed
Step 3 (Moderate Persistent): Low-dose ICS/LABA or Medium-dose ICS
Step 4-5 (Severe): Medium/High dose ICS/LABA, consider add-on therapy

SABA: Short-acting beta-agonist; ICS: Inhaled corticosteroid; LABA: Long-acting beta-agonist

3.6 Pulmonary Tuberculosis (PTB)

Key Definitions

PTB: TB affecting lungs (most common form)
Relapse: TB returns after previous cure/completion
Drug-resistant TB: Resistance to any first-line anti-TB drug
MDR-TB: Resistant to at least INH and Rifampicin
XDR-TB: MDR-TB + resistance to any fluoroquinolone and at least one injectable second-line drug

DOTS Therapy (Nepal Guideline)

New TB Cases (Category I):

Intensive Phase (2 months): HRZE (Isoniazid, Rifampicin, Pyrazinamide, Ethambutol)

Continuation Phase (4 months): HR (Isoniazid, Rifampicin)

Prevention and Control

BCG Vaccination (given at birth in Nepal)
Early diagnosis and complete treatment of cases (DOTS)
Contact tracing and screening
Infection Control: Cough etiquette, respiratory isolation
Management of Latent TB Infection (LTBI) in high-risk contacts

Clinical Tips & Memory Aids

COPD vs Asthma: Key Differences

Onset: COPD usually >40 years, Asthma often childhood/young adulthood
Smoking History: COPD almost always, Asthma not necessarily
Reversibility: COPD irreversible/fixed obstruction, Asthma reversible
Inflammation: COPD neutrophilic, Asthma eosinophilic

Important Mnemonics

Asthma Triggers: ACE – Allergens, Cold air, Exercise
Pneumonia Common Organisms: SPH – Streptococcus pneumoniae, Haemophilus influenzae
TB Symptoms: 2-3 weeks – Cough lasting 2-3 weeks is red flag for TB
COPD Management: SABIC – Smoking cessation, Antibiotics (exacerbation), Bronchodilators, ICS, Cardio-pulmonary rehab