Medicine 1: respiratory Medicine kmtc well written notes exam oriented

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Here are your comprehensive Medicine 1: Respiratory Medicine — KMTC Exam-Oriented Notes, compiled from Harrison's Principles of Internal Medicine 22E and Murray & Nadel's Textbook of Respiratory Medicine. Here's what's covered:

What's Included (10 Units)

Unit	Topic
1	Asthma — pathophysiology, GINA classification, SABA/ICS stepwise therapy, acute management
2	COPD — "Blue Bloater vs Pink Puffer," GOLD grading, BODE index, LTOT criteria, AECOPD
3	Pneumonia — CAP/HAP, atypical organisms, consolidation signs, CURB-65 score
4	Tuberculosis — Ghon complex, AFB/GeneXpert, 2HRZE/4HR regimen, drug side effects, MDR-TB
5	Pleural Effusion — transudate vs exudate, Light's Criteria, ADA for TB
6	Bronchiectasis — causes, signet ring sign on HRCT, Kartagener's, management
7	Respiratory Failure — Type 1 vs Type 2, ARDS Berlin criteria, lung-protective ventilation
8	Lung Cancer — NSCLC vs SCLC, Horner's/SVC syndrome, paraneoplastic syndromes, targeted therapy
9	Pulmonary Embolism — Wells score, D-dimer, CTPA, S1Q3T3, thrombolysis
10	Pneumothorax — tension PE emergency management, chest drain landmarks

Key Exam Tips Highlighted Throughout

Ethambutol → Optic neuritis | Isoniazid → Peripheral neuropathy (give B6) | Rifampicin → Orange urine + enzyme inducer
COPD: Controlled O₂ (88–92%) — never high-flow; NIV if pH <7.35 + PaCO₂ >6 kPa
Asthma: High-flow O₂ freely in acute attacks
Clubbing in COPD → investigate for lung cancer
CURB-65 ≥3 → severe pneumonia, hospitalize
Tension pneumothorax → clinical diagnosis, immediate needle decompression — do NOT wait for CXR
Light's criteria: exudate if protein >0.5, LDH >0.6, or LDH >2/3 ULN

Create mcqs , saqs and laqs all with answers on it

MEDICINE 1: RESPIRATORY MEDICINE

EXAM QUESTIONS WITH ANSWERS

MCQs | SAQs | LAQs — KMTC Exam-Oriented

SECTION A: MULTIPLE CHOICE QUESTIONS (MCQs)

(50 Questions — Choose the BEST answer)

1. A 25-year-old presents with episodic wheezing, chest tightness, and cough that worsens at night. Spirometry shows FEV1/FVC of 0.65, which improves to 0.74 after salbutamol. What is the most likely diagnosis?

A) COPD
B) Bronchiectasis
C) Asthma
D) Pulmonary fibrosis

✅ Answer: C — Asthma Reversible airflow obstruction (≥12% and ≥200 mL improvement post-bronchodilator) in a young patient with episodic symptoms is classic asthma.

2. Which of the following is the CORNERSTONE of long-term asthma maintenance therapy?

A) Long-acting beta-2 agonists (LABA)
B) Inhaled corticosteroids (ICS)
C) Short-acting beta-2 agonists (SABA)
D) Theophylline

✅ Answer: B — Inhaled corticosteroids ICS (beclomethasone, budesonide, fluticasone) are the cornerstone of maintenance therapy, targeting airway inflammation.

3. A patient with severe acute asthma is not responding to nebulized salbutamol and systemic steroids. What is the NEXT most appropriate drug to add?

A) Oral theophylline
B) IV magnesium sulfate
C) Subcutaneous epinephrine
D) IV salbutamol bolus

✅ Answer: B — IV magnesium sulfate Magnesium sulfate is indicated in life-threatening/severe acute asthma not responding to initial bronchodilators and steroids.

4. Which finding on spirometry CONFIRMS a diagnosis of COPD?

A) FEV1/FVC < 0.70 pre-bronchodilator
B) FEV1/FVC < 0.70 post-bronchodilator
C) FEV1 < 80% predicted
D) Reduced FVC with normal FEV1/FVC

✅ Answer: B — FEV1/FVC < 0.70 post-bronchodilator GOLD guidelines define COPD as persistent airflow limitation: FEV1/FVC <0.70 AFTER bronchodilator administration.

5. A 65-year-old smoker with COPD has PaO₂ of 54 mmHg at rest. What is the MOST appropriate long-term management?

A) Start inhaled corticosteroids
B) Initiate long-term oxygen therapy (LTOT)
C) Begin pulmonary rehabilitation only
D) Prescribe oral theophylline

✅ Answer: B — Long-term oxygen therapy (LTOT) LTOT is indicated when PaO₂ ≤55 mmHg (or SpO₂ ≤88%) at rest. It is the only intervention shown to improve survival in severe COPD with hypoxemia.

6. A 70-year-old with known COPD presents with worsening dyspnea, increased sputum production, and purulent (green) sputum. ABG shows pH 7.30, PaCO₂ 65 mmHg, PaO₂ 50 mmHg. Which intervention is MOST appropriate?

A) High-flow O₂ via non-rebreather mask
B) Non-invasive ventilation (BiPAP)
C) Immediate endotracheal intubation
D) IV aminophylline infusion

✅ Answer: B — Non-invasive ventilation (BiPAP) NIV is first-line for AECOPD with type 2 respiratory failure when pH <7.35 and PaCO₂ >6 kPa. Controlled O₂ should be given, not high-flow.

7. What oxygen saturation target should be used when administering oxygen to a patient with acute exacerbation of COPD?

A) 94–98%
B) 99–100%
C) 88–92%
D) 85–88%

✅ Answer: C — 88–92% In COPD, high O₂ may suppress the hypoxic drive in CO₂ retainers, worsening hypercapnia. Target SpO₂ 88–92% using Venturi mask (24–28% FiO₂).

8. The #1 most common cause of community-acquired pneumonia (CAP) is:

A) Haemophilus influenzae
B) Mycoplasma pneumoniae
C) Streptococcus pneumoniae
D) Legionella pneumophila

✅ Answer: C — Streptococcus pneumoniae Pneumococcus is the single most common cause of CAP across all age groups.

9. A 45-year-old returning from a hotel conference develops high fever, confusion, diarrhea, hyponatremia, and elevated liver enzymes with severe pneumonia. The MOST likely causative organism is:

A) Streptococcus pneumoniae
B) Klebsiella pneumoniae
C) Legionella pneumophila
D) Mycoplasma pneumoniae

✅ Answer: C — Legionella pneumophila Legionnaire's disease: hotel/water system exposure + extrapulmonary features (confusion, diarrhea, hyponatremia, elevated LFTs). Diagnosed by urinary antigen.

10. Using CURB-65 scoring, which patient should be managed as an OUTPATIENT?

A) 70-year-old with confusion and RR 32/min
B) 50-year-old with urea 8 mmol/L and BP 85/55
C) 30-year-old, alert, RR 18/min, BP 130/80, urea 5 mmol/L
D) 68-year-old with RR 20/min and confusion

✅ Answer: C — 30-year-old with no CURB-65 features CURB-65 score of 0–1 = low severity → suitable for outpatient treatment. Option C scores 0 points.

11. A patient's sputum stained with Ziehl-Neelsen shows red rods against a blue background. What is the MOST likely diagnosis?

A) Pneumocystis jirovecii pneumonia
B) Pneumococcal pneumonia
C) Pulmonary tuberculosis
D) Aspergillosis

✅ Answer: C — Pulmonary tuberculosis ZN (acid-fast) staining shows M. tuberculosis as red/pink rods (acid-fast bacilli) on a blue counterstained background.

12. Which drug used in TB treatment can cause optic neuritis, requiring monitoring of visual acuity and color vision?

A) Isoniazid
B) Rifampicin
C) Ethambutol
D) Pyrazinamide

✅ Answer: C — Ethambutol Ethambutol's main toxicity is retrobulbar optic neuritis → colour vision loss (especially red-green) and reduced visual acuity. Baseline visual assessment is mandatory.

13. What is the standard drug regimen for drug-susceptible pulmonary tuberculosis?

A) Isoniazid + Rifampicin × 9 months
B) 2HRZE / 4HR (total 6 months)
C) 2HRE / 6HR (total 8 months)
D) Isoniazid alone × 6 months

✅ Answer: B — 2HRZE / 4HR Intensive phase: Isoniazid (H), Rifampicin (R), Pyrazinamide (Z), Ethambutol (E) for 2 months; Continuation phase: H + R for 4 months.

14. A patient on TB treatment develops peripheral neuropathy. Which drug is responsible and what is the preventive supplement?

A) Rifampicin — Vitamin C
B) Isoniazid — Pyridoxine (Vitamin B6)
C) Pyrazinamide — Thiamine (Vitamin B1)
D) Ethambutol — Folic acid

✅ Answer: B — Isoniazid — Pyridoxine (Vitamin B6) Isoniazid inhibits pyridoxine metabolism, causing peripheral neuropathy. Pyridoxine (B6) supplementation prevents this.

15. Rifampicin causes which of the following well-known side effect that patients must be warned about?

A) Green discoloration of urine
B) Orange/red discoloration of urine, sweat, tears
C) Blue discoloration of teeth
D) Yellow discoloration of nails

✅ Answer: B — Orange/red discoloration of body fluids Rifampicin causes orange coloration of urine, saliva, sweat, and tears — a benign but alarming side effect patients must be counseled about.

16. Which of the following correctly distinguishes an EXUDATIVE from a transudative pleural effusion using Light's criteria?

A) Pleural fluid protein/serum protein > 0.3
B) Pleural fluid LDH/serum LDH > 0.8
C) Pleural fluid protein/serum protein > 0.5
D) Pleural fluid glucose < 5.0 mmol/L

✅ Answer: C — Pleural fluid protein/serum protein > 0.5 Light's criteria for exudate: (1) PF/serum protein >0.5, (2) PF/serum LDH >0.6, or (3) PF LDH >2/3 ULN serum LDH.

17. The MOST common cause of a TRANSUDATIVE pleural effusion is:

A) Pulmonary embolism
B) Bacterial pneumonia
C) Malignancy
D) Left ventricular failure (congestive heart failure)

✅ Answer: D — Left ventricular failure CHF is the leading cause of transudative pleural effusion due to elevated hydrostatic pressure.

18. A patient with bacterial pneumonia develops a pleural effusion with pH 7.15, glucose 1.8 mmol/L, and frank pus on aspiration. What is the NEXT management step?

A) Observation with antibiotics alone
B) Repeated thoracentesis
C) Chest drain insertion + antibiotics (empyema management)
D) Systemic steroids

✅ Answer: C — Chest drain + antibiotics Frank pus = empyema. A complicated parapneumonic effusion (pH <7.2, glucose <2.2, frank pus) requires chest drain drainage + antibiotics.

19. Adenosine deaminase (ADA) level >40 U/L in pleural fluid is most suggestive of:

A) Malignant effusion
B) Cardiac failure
C) Tuberculous pleuritis
D) Rheumatoid pleuritis

✅ Answer: C — Tuberculous pleuritis ADA >40 U/L in pleural fluid has high sensitivity and specificity for TB pleuritis. TB effusions are lymphocytic exudates.

20. Which of the following is the GOLD STANDARD investigation for diagnosing bronchiectasis?

A) Plain CXR
B) Spirometry
C) HRCT (High-Resolution CT) of the chest
D) Bronchoscopy

✅ Answer: C — HRCT chest HRCT shows the "signet ring sign" (dilated bronchus larger than accompanying artery), bronchial wall thickening, and lack of tapering — diagnostic hallmarks of bronchiectasis.

21. Which syndrome presents with bronchiectasis, chronic sinusitis, and situs inversus?

A) Goodpasture's syndrome
B) Kartagener's syndrome
C) Marfan's syndrome
D) Yellow nail syndrome

✅ Answer: B — Kartagener's syndrome Kartagener's is a form of Primary Ciliary Dyskinesia (PCD): defective cilia → bronchiectasis + sinusitis + situs inversus (dextrocardia).

22. What type of emphysema is associated with alpha-1 antitrypsin deficiency?

A) Centrilobular (centriacinar)
B) Paraseptal
C) Panlobular (panacinar)
D) Irregular

✅ Answer: C — Panlobular (panacinar) α1-antitrypsin deficiency causes panacinar emphysema predominantly in the LOWER lobes. Smoking causes centrilobular emphysema in the upper lobes.

23. In COPD, clubbing of the fingers is:

A) A common finding in advanced disease
B) Not a feature of COPD; its presence warrants investigation for lung cancer
C) A sign of cor pulmonale
D) Caused by chronic hypoxemia in COPD

✅ Answer: B — Not a feature of COPD Clubbing is NOT caused by COPD. Its presence in a COPD patient should prompt investigation for lung cancer (most likely explanation).

24. A 20-year-old tall, thin male develops sudden right-sided chest pain and dyspnea. CXR shows a visible lung edge with no lung markings beyond it. The MOST appropriate initial management for a large (>2 cm) pneumothorax is:

A) Emergency thoracotomy
B) Immediate chest drain
C) Needle aspiration
D) Observation and supplemental O₂

✅ Answer: C — Needle aspiration For a large primary spontaneous pneumothorax (≥2 cm) in a stable patient, needle aspiration is the FIRST-LINE intervention. Chest drain if aspiration fails.

25. A trauma patient suddenly develops extreme tachycardia, hypotension, absent breath sounds on the left, and tracheal deviation to the RIGHT. The MOST likely diagnosis is:

A) Massive haemothorax
B) Left-sided tension pneumothorax
C) Left-sided simple pneumothorax
D) Cardiac tamponade

✅ Answer: B — Left-sided tension pneumothorax Trachea deviates AWAY from the tension side. Life-threatening emergency requiring immediate needle decompression (2nd ICS, MCL) without waiting for CXR.

26. The GOLD STANDARD investigation for confirming pulmonary embolism is:

A) V/Q scan
B) Chest X-ray
C) CT Pulmonary Angiography (CTPA)
D) ECG

✅ Answer: C — CTPA CTPA is the gold standard for PE diagnosis, offering direct visualization of thrombus in pulmonary arteries.

27. A 35-year-old woman on the oral contraceptive pill develops acute dyspnea and pleuritic chest pain 2 days after a long-haul flight. D-dimer is elevated. ECG shows S1Q3T3. The MOST likely diagnosis is:

A) Spontaneous pneumothorax
B) Pulmonary embolism
C) Acute pericarditis
D) Aortic dissection

✅ Answer: B — Pulmonary embolism Multiple risk factors: OCP + prolonged immobility. S1Q3T3 (S wave in lead I, Q wave and inverted T in lead III) = right heart strain from PE.

28. What is the FIRST investigation in a patient with suspected PE and LOW pre-test probability?

A) CTPA immediately
B) D-dimer
C) V/Q scan
D) Doppler leg ultrasound

✅ Answer: B — D-dimer A negative D-dimer (by ELISA) effectively rules out PE in low-probability patients. If elevated → proceed to CTPA.

29. Small cell lung cancer (SCLC) is associated with which paraneoplastic syndrome causing hyponatremia?

A) Ectopic ACTH secretion
B) PTHrP (parathyroid hormone-related peptide)
C) SIADH (syndrome of inappropriate ADH)
D) Eaton-Lambert syndrome

✅ Answer: C — SIADH SCLC commonly causes SIADH → dilutional hyponatremia. SCLC also causes ectopic ACTH (Cushing's) and Eaton-Lambert myasthenic syndrome.

30. A Pancoast (superior sulcus) tumor compressing the sympathetic chain presents with:

A) Contralateral ptosis, miosis, anhidrosis
B) Ipsilateral ptosis, miosis, anhidrosis (Horner's syndrome)
C) Bilateral limb weakness
D) Facial flushing and hypertension

✅ Answer: B — Ipsilateral Horner's syndrome Pancoast tumor (apex of lung) compresses the sympathetic chain → ipsilateral Horner's syndrome: ptosis (droopy lid), miosis (small pupil), anhidrosis (no sweating on that side).

31. Which type of lung cancer most commonly causes hypercalcemia as a paraneoplastic syndrome?

A) Small cell carcinoma
B) Adenocarcinoma
C) Squamous cell carcinoma
D) Large cell carcinoma

✅ Answer: C — Squamous cell carcinoma SCC secretes PTHrP (parathyroid hormone-related protein) → hypercalcemia. Note: SCLC causes SIADH and Cushing's.

32. The MOST common type of non-small cell lung cancer (NSCLC), especially in non-smokers and women, is:

A) Squamous cell carcinoma
B) Large cell carcinoma
C) Adenocarcinoma
D) Carcinoid tumor

✅ Answer: C — Adenocarcinoma Adenocarcinoma is the most common NSCLC overall and the most common lung cancer in non-smokers/women. Located peripherally; associated with EGFR and ALK mutations.

33. ARDS (Acute Respiratory Distress Syndrome) is defined by which of the following PaO₂/FiO₂ ratio (Berlin criteria)?

A) PaO₂/FiO₂ < 500
B) PaO₂/FiO₂ < 400
C) PaO₂/FiO₂ < 300
D) PaO₂/FiO₂ < 100

✅ Answer: C — PaO₂/FiO₂ < 300 Berlin criteria: Mild ARDS = 200–300; Moderate = 100–200; Severe = <100. All require PEEP ≥5 cmH₂O.

34. The recommended tidal volume for lung-protective mechanical ventilation in ARDS is:

A) 12 mL/kg ideal body weight
B) 10 mL/kg ideal body weight
C) 6 mL/kg ideal body weight
D) 8 mL/kg ideal body weight

✅ Answer: C — 6 mL/kg ideal body weight Low tidal volume (6 mL/kg IBW) reduces volutrauma in ARDS, significantly reducing mortality (ARDSNet trial: 31% vs 39.8% mortality).

35. Which of the following ABG results is consistent with TYPE 2 respiratory failure?

A) PaO₂ 55 mmHg, PaCO₂ 35 mmHg
B) PaO₂ 55 mmHg, PaCO₂ 60 mmHg
C) PaO₂ 80 mmHg, PaCO₂ 35 mmHg
D) PaO₂ 95 mmHg, PaCO₂ 50 mmHg

✅ Answer: B — PaO₂ 55 mmHg, PaCO₂ 60 mmHg Type 2 (ventilatory failure) = ↓PaO₂ (<60 mmHg) AND ↑PaCO₂ (>45 mmHg). Causes: severe COPD, AECOPD, NM disease.

36. A sputum Mantoux test placed intradermally is read after:

A) 24 hours
B) 48–72 hours
C) 7 days
D) Immediately

✅ Answer: B — 48–72 hours The tuberculin skin test (Mantoux) must be read at 48–72 hours after intradermal injection of 5 TU PPD by measuring the induration (not redness).

37. Which of the following represents MDR-TB (Multi-Drug Resistant Tuberculosis)?

A) Resistance to ethambutol and pyrazinamide only
B) Resistance to isoniazid alone
C) Resistance to at least isoniazid AND rifampicin
D) Resistance to streptomycin and ethambutol

✅ Answer: C — Resistance to isoniazid AND rifampicin MDR-TB = resistance to the two most powerful first-line drugs: isoniazid and rifampicin.

38. What is the MOST important single intervention to slow the progression of COPD?

A) Long-term oxygen therapy
B) Inhaled corticosteroids
C) Smoking cessation
D) Pulmonary rehabilitation

✅ Answer: C — Smoking cessation Smoking cessation is the single most important intervention in COPD. It slows FEV1 decline rate, reduces exacerbations, and improves prognosis.

39. A 40-year-old non-smoker with progressive emphysema predominantly in the LOWER lobes should be investigated for:

A) Asthma
B) Alpha-1 antitrypsin deficiency
C) Cystic fibrosis
D) Kartagener's syndrome

✅ Answer: B — Alpha-1 antitrypsin deficiency Lower lobe panacinar emphysema in a young non-smoker = classic presentation of α1-antitrypsin deficiency.

40. Hypertrophic pulmonary osteoarthropathy (HPOA) presents with:

A) Muscle weakness and fatigue
B) Severe clubbing + periosteal new bone formation + bone pain
C) Facial puffiness and arm swelling
D) Ptosis, miosis, and anhidrosis

✅ Answer: B — Severe clubbing + periosteal new bone formation + bone pain HPOA is a paraneoplastic syndrome mainly associated with adenocarcinoma and SCC of the lung.

41. Superior vena cava (SVC) syndrome caused by lung cancer presents with:

A) Lower limb edema and ascites
B) Facial/neck swelling, plethora, dilated neck and arm veins, headache
C) Jaundice and hepatomegaly
D) Calf pain and warmth

✅ Answer: B — Facial/neck swelling, plethora, dilated veins SVC obstruction (usually by central lung tumor or mediastinal lymph nodes) causes venous hypertension in the upper body: facial plethora, neck/arm swelling, headache, dilated veins.

42. The most common cause of ARDS is:

A) Multiple blood transfusions
B) Near-drowning
C) Sepsis
D) Pancreatitis

✅ Answer: C — Sepsis Sepsis is the single most common cause of ARDS, followed by pneumonia, aspiration, trauma, and pancreatitis.

43. Which antibiotic is FIRST-LINE treatment for Legionella pneumonia?

A) Amoxicillin
B) Ceftriaxone
C) Fluoroquinolone (levofloxacin) or azithromycin
D) Vancomycin

✅ Answer: C — Fluoroquinolone or azithromycin Legionella is an intracellular organism — beta-lactams are ineffective. Macrolides (azithromycin) or fluoroquinolones (levofloxacin) are used.

44. A 3-layer sputum appearance (frothy top, mucoid middle, purulent bottom) on standing is characteristic of:

A) Lung abscess
B) Bronchiectasis
C) Pneumonia
D) Pulmonary edema

✅ Answer: B — Bronchiectasis The classic 3-layer sputum (frothy/mucoid/purulent layers) on standing in a large-volume pot is pathognomonic of bronchiectasis.

45. A patient with asthma develops ASA sensitivity and nasal polyps. Which drug class should be AVOIDED?

A) ICS
B) Leukotriene receptor antagonists
C) NSAIDs and aspirin
D) Anticholinergics

✅ Answer: C — NSAIDs and aspirin Samter's triad: asthma + nasal polyps + aspirin/NSAID sensitivity. NSAIDs trigger bronchoconstriction via COX inhibition shifting arachidonic acid to leukotriene pathway.

46. Which of the following is the MOST appropriate maintenance treatment for a COPD patient with frequent exacerbations and blood eosinophils >300 cells/μL?

A) LABA + LAMA
B) LABA + LAMA + ICS (triple therapy)
C) SABA alone
D) Oral prednisolone

✅ Answer: B — LABA + LAMA + ICS Triple therapy (LABA + LAMA + ICS) is recommended for COPD patients with frequent exacerbations AND elevated blood eosinophils, where ICS benefit is greatest.

47. On chest X-ray, a pleural effusion becomes visible when the volume of fluid is at least:

A) 50 mL
B) 100 mL
C) 200–300 mL
D) 500 mL

✅ Answer: C — 200–300 mL On an upright PA CXR, approximately 200–300 mL of fluid is needed to blunt the costophrenic angle. On a lateral film, as little as 75 mL may be visible.

48. A patient with COPD develops loud P2 heart sound, raised JVP, peripheral edema, and right ventricular hypertrophy on ECG. The MOST likely complication is:

A) Left ventricular failure
B) Cardiac tamponade
C) Cor pulmonale
D) Infective endocarditis

✅ Answer: C — Cor pulmonale Cor pulmonale = right heart failure secondary to pulmonary hypertension from chronic lung disease. Features: loud P2, RVH, elevated JVP, peripheral edema.

49. Which investigation simultaneously detects M. tuberculosis AND tests for rifampicin resistance?

A) Mantoux (TST)
B) Ziehl-Neelsen sputum smear
C) GeneXpert MTB/RIF (Xpert)
D) IGRA (Quantiferon-TB Gold)

✅ Answer: C — GeneXpert MTB/RIF GeneXpert is a rapid molecular (PCR-based) test that detects MTB DNA and simultaneously identifies rifampicin resistance mutations in ~2 hours. WHO-endorsed.

50. A patient with longstanding rheumatoid arthritis develops an exudative, lymphocyte-rich pleural effusion with very LOW glucose (<1.6 mmol/L). The MOST likely diagnosis is:

A) TB pleuritis
B) Malignant effusion
C) Rheumatoid pleuritis
D) Parapneumonic effusion

✅ Answer: C — Rheumatoid pleuritis Rheumatoid pleural effusion characteristically has extremely LOW glucose (<1.6 mmol/L) due to impaired glucose transport across the inflamed pleura — a hallmark finding.

SECTION B: SHORT ANSWER QUESTIONS (SAQs)

(Answer in 5–10 lines each)

SAQ 1

Define asthma and list SIX goals of asthma therapy.

✅ Answer: Asthma is a chronic inflammatory airway disease characterized by episodic, reversible airflow obstruction, airway hyperresponsiveness, and airway inflammation (predominantly eosinophilic).

Six Goals of Asthma Therapy (GINA):

Reduction of symptoms to ≤2 times/week
Nighttime awakenings to ≤2 times/month
Reliever use to ≤2 times/week (except pre-exercise)
No more than 1 exacerbation/year
Optimization of lung function (FEV1 ≥80% predicted)
Maintenance of normal daily activities with minimal side effects

SAQ 2

State FOUR differences between asthma and COPD.

✅ Answer:

Feature	Asthma	COPD
Age of onset	Usually young (<40 yrs)	Usually >40 years
Smoking history	Not always present	Nearly universal
Airflow obstruction	Fully reversible	Partially/irreversible
FEV1/FVC post-BD	≥0.70 (normalizes)	<0.70 (persists)
Eosinophilia	Common	Less common
CXR	Usually normal	Hyperinflation, bullae

SAQ 3

Outline the management of an acute exacerbation of COPD (AECOPD).

✅ Answer:

Controlled oxygen (target SpO₂ 88–92%) via Venturi mask (24–28% FiO₂)
Nebulized bronchodilators: Salbutamol (SABA) + Ipratropium (SAMA) every 4–6 hours
Systemic corticosteroids: Prednisolone 30–40 mg orally for 5 days
Antibiotics if purulent sputum: Amoxicillin, Doxycycline, or Co-amoxiclav
NIV (BiPAP) if pH <7.35 and PaCO₂ >6 kPa — first-line for type 2 respiratory failure
Invasive ventilation if NIV fails, pH <7.25, or hemodynamic instability
DVT prophylaxis, fluids, monitor ABG

SAQ 4

Define CURB-65 and explain how it is used to guide management of pneumonia.

✅ Answer: CURB-65 is a clinical severity scoring system for community-acquired pneumonia:

Letter	Criterion	Points
C	Confusion (new onset)	1
U	Urea >7 mmol/L	1
R	Respiratory rate ≥30/min	1
B	BP systolic <90 or diastolic ≤60 mmHg	1
65	Age ≥65 years	1

Management guide:

Score 0–1: Low risk → outpatient oral antibiotics
Score 2: Moderate → hospital admission; consider IV antibiotics
Score 3–5: Severe → hospital admission, IV antibiotics; consider ICU if 4–5

SAQ 5

State the standard TB treatment regimen and list the side effects of each drug.

✅ Answer: Regimen: 2HRZE / 4HR (total 6 months)

Intensive phase (2 months): Isoniazid (H) + Rifampicin (R) + Pyrazinamide (Z) + Ethambutol (E)
Continuation phase (4 months): Isoniazid (H) + Rifampicin (R)

Drug	Key Side Effects
Isoniazid	Peripheral neuropathy (prevent with B6), hepatotoxicity
Rifampicin	Orange body fluids, hepatotoxicity, enzyme inducer (↓OCP/warfarin)
Pyrazinamide	Hyperuricemia/gout, hepatotoxicity, arthralgia
Ethambutol	Optic neuritis (reduced visual acuity + color vision)

SAQ 6

State Light's criteria for distinguishing exudative from transudative pleural effusion.

✅ Answer: A pleural effusion is an EXUDATE if it meets at least ONE of the following criteria (Light's criteria):

Pleural fluid protein / Serum protein > 0.5
Pleural fluid LDH / Serum LDH > 0.6
Pleural fluid LDH > 2/3 of the upper limit of normal for serum LDH

If NONE of these criteria are met → TRANSUDATE

Clinical note: These criteria misclassify ~25% of diuretic-treated transudates as exudates. The serum–effusion albumin gradient (>12 g/L favors transudate) can correct this.

SAQ 7

Define respiratory failure and differentiate Type 1 from Type 2.

✅ Answer: Respiratory failure = inability of the respiratory system to maintain adequate gas exchange at rest.

Feature	Type 1 (Hypoxaemic)	Type 2 (Hypercapnic/Ventilatory)
PaO₂	<60 mmHg (↓)	<60 mmHg (↓)
PaCO₂	Normal or ↓	>45 mmHg (↑)
Mechanism	V/Q mismatch, shunt (gas exchanger fails)	Alveolar hypoventilation (pump fails)
Causes	Pneumonia, ARDS, pulmonary oedema, PE	AECOPD, severe asthma, NM diseases, drug OD
O₂ therapy	High-flow O₂ (94–98%)	Controlled O₂ (88–92%); NIV if needed

SAQ 8

List FIVE clinical features of pulmonary embolism and state the gold standard investigation.

✅ Answer: Clinical features of PE:

Sudden onset dyspnea (most common)
Pleuritic chest pain
Haemoptysis
Tachycardia
Signs of DVT: unilateral calf pain, swelling, warmth

Additional features: Hypoxemia, tachypnea, low-grade fever, syncope/collapse (massive PE), pleural rub (infarction)

ECG: Sinus tachycardia (most common); S1Q3T3 (right heart strain — classic but not common)

Gold standard investigation: CT Pulmonary Angiography (CTPA)

D-dimer first (rules out PE if negative in low-probability cases)
CTPA confirms diagnosis by direct visualization of thrombus

SAQ 9

Outline the management of a tension pneumothorax.

✅ Answer: Tension pneumothorax is a medical emergency — one-way valve traps air progressively, causing mediastinal shift and obstructed venous return.

Clinical signs: Severe dyspnea, tracheal deviation AWAY from affected side, absent breath sounds, hyperresonance, hypotension, tachycardia, JVP elevation, cyanosis

Management:

Do NOT wait for CXR — this is a clinical diagnosis
Immediate needle decompression: 14G (orange) cannula into the 2nd intercostal space, midclavicular line — a rush of air confirms diagnosis
Follow immediately with chest drain insertion (5th ICS, anterior axillary line) — needle decompression is temporary
O₂ (high flow)
IV access, monitoring, analgesia

SAQ 10

List FIVE causes of haemoptysis and state two investigations.

✅ Answer: Causes of haemoptysis:

Pulmonary tuberculosis (#1 cause in developing countries)
Bronchogenic carcinoma (lung cancer)
Bronchiectasis
Pneumonia
Pulmonary embolism (pulmonary infarction)
(Others: mitral stenosis, Goodpasture's, AVM, bronchitis)

Investigations:

CXR: mass, cavitation, consolidation, cardiomegaly (MS)
Bronchoscopy: localizes source, allows biopsy; best for central lesions
(Additional: CT chest, sputum AFB × 3, CTPA for PE)

SECTION C: LONG ANSWER QUESTIONS (LAQs)

(Answer in detail — structured essay format)

LAQ 1

Describe the pathophysiology, clinical features, investigations, and management of BRONCHIAL ASTHMA. Include the stepwise approach to treatment.

✅ ANSWER:

BRONCHIAL ASTHMA

Definition

Asthma is a chronic inflammatory airway disease characterized by:

Episodic, reversible airflow obstruction
Airway hyperresponsiveness (to allergens, cold air, exercise, irritants)
Airway inflammation (predominantly eosinophilic)

Prevalence: affects ~300 million people worldwide; increasing in urbanized areas.

Pathophysiology

Phase 1 — Sensitization:

Initial allergen exposure → Th2-cell activation → IL-4, IL-5, IL-13 release → B cells produce IgE
IgE binds to mast cells on airway epithelium (sensitization)

Phase 2 — Early Allergic Reaction (0–2 hours after re-exposure):

Re-exposure to allergen → cross-links IgE on mast cells → degranulation
Release of: Histamine, Leukotrienes (LTC4, LTD4), Prostaglandin D2, Bradykinin
Effects: Bronchoconstriction, increased vascular permeability, mucus secretion

Phase 3 — Late Allergic Reaction (4–12 hours):

Recruitment of eosinophils, neutrophils, T-cells → sustained inflammation
Eosinophil major basic protein damages airway epithelium
Sustained bronchoconstriction + mucosal edema + mucus plugging

Phase 4 — Airway Remodeling (chronic disease):

Subepithelial fibrosis
Smooth muscle hypertrophy and hyperplasia
Goblet cell hyperplasia (mucus overproduction)
Angiogenesis
Leads to irreversible component in some patients

Triggers

Allergens (house dust mite, pollen, pet dander)
Respiratory infections (viral — RSV, rhinovirus)
Exercise (especially cold, dry air)
Aspirin/NSAIDs (via leukotriene pathway — Samter's triad)
Beta-blockers (bronchoconstriction)
Cold air, smoke, irritants, emotional stress
Occupational sensitizers

Clinical Features

Symptoms (classic triad):

Episodic wheezing (high-pitched expiratory)
Breathlessness (worse at night/early morning)
Chest tightness
Cough — often dry, nocturnal; or productive

During attack:

Prolonged expiration, use of accessory muscles
Diffuse bilateral wheeze on auscultation
Tachypnea, tachycardia, diaphoresis

Severe indicators:

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SpO₂ <92%
Pulsus paradoxus >20 mmHg
Peak flow <50% predicted

Life-threatening ("SILENT CHEST"):

No wheeze (no air movement)
Bradycardia, confusion, cyanosis — impending respiratory arrest

GINA Severity Classification

Class	Daytime Symptoms	Nighttime	FEV1%
Intermittent	≤2/week	≤2/month	≥80%
Mild persistent	>2/week, not daily	>2/month	≥80%
Moderate persistent	Daily	>1/week	60–79%
Severe persistent	Continuous	Frequent	<60%

Investigations

Spirometry: ↓FEV1, ↓FEV1/FVC; reversibility ≥12% + ≥200 mL after SABA confirms asthma
Peak expiratory flow (PEF): diurnal variation >20% (measured morning + evening × 2 weeks)
Bronchial challenge test: methacholine provocation — confirms hyperresponsiveness in normal spirometry
CXR: usually normal; hyperinflation in acute severe attack; rules out pneumothorax
ABG (severe attack): early = respiratory alkalosis (hyperventilation); late = respiratory acidosis (fatigue)
Blood/sputum eosinophils, serum IgE, skin prick testing, specific IgE RAST
FeNO (fractional exhaled NO): marker of eosinophilic inflammation (≥25 ppb positive)

Management

A. Non-pharmacological

Identify and AVOID triggers (allergens, smoking, occupational exposures)
Annual influenza vaccine; pneumococcal vaccine
Allergen immunotherapy (selected allergic patients)
Written asthma action plan
Patient education

B. Stepwise Pharmacological Therapy (GINA 2023)

RELIEVER (all steps): SABA — Salbutamol PRN

Step	Controller Therapy
1 (Intermittent)	Low-dose ICS-formoterol PRN
2 (Mild persistent)	Low-dose ICS daily
3 (Moderate)	Low-dose ICS + LABA
4 (Severe)	Medium/high ICS + LABA
5 (Refractory)	Add biologic ± low-dose OCS

Drug classes:

SABA (Salbutamol): immediate bronchodilation — rescue inhaler
ICS (Budesonide, Beclomethasone): anti-inflammatory — cornerstone
LABA (Salmeterol, Formoterol): long-acting bronchodilation — NEVER without ICS
LTRA (Montelukast): anti-leukotriene — especially aspirin-sensitive asthma
LAMA (Tiotropium): add-on for severe uncontrolled asthma at Step 4–5
Theophylline: bronchodilator + weak anti-inflammatory; narrow therapeutic window
Anti-IgE (Omalizumab): severe allergic asthma (IgE 30–700 IU/mL + sensitized)
Anti-IL-5 (Mepolizumab, Reslizumab): severe eosinophilic asthma (blood eosinophils ≥300)

C. Management of Acute Severe Asthma

Sit up, reassure, high-flow O₂ (15 L/min, target SpO₂ 94–98%)
Nebulized Salbutamol 5 mg every 20 min × 3 doses (continuous in very severe)
Nebulized Ipratropium 0.5 mg (add to salbutamol in moderate-severe)
Systemic corticosteroids: Prednisolone 40–50 mg orally OR Hydrocortisone 100 mg IV
IV Magnesium Sulfate 2 g over 20 min — if life-threatening/not responding
CXR: exclude pneumothorax
ABG: guide need for intubation
Escalate to ICU if:
- Silent chest
- Confusion/coma
- SpO₂ <92% despite treatment
- Rising PaCO₂
Endotracheal intubation and mechanical ventilation as last resort

Monitoring & Follow-up

Review after 4–6 weeks of new therapy
Step DOWN when controlled for 3 months
Assess inhaler technique, adherence, comorbidities (rhinitis, GERD)

LAQ 2

Describe the aetiology, pathology, clinical features, investigations, and management of PULMONARY TUBERCULOSIS.

✅ ANSWER:

PULMONARY TUBERCULOSIS

Definition

Tuberculosis (TB) is a chronic granulomatous infectious disease caused by Mycobacterium tuberculosis, primarily affecting the lungs, with potential for dissemination to any organ.

Epidemiology

~10.6 million new cases/year globally (WHO 2022)
Leading infectious disease cause of death after COVID-19
High burden: sub-Saharan Africa, South/Southeast Asia
Risk factors: HIV infection (↑30× risk), malnutrition, diabetes mellitus, immunosuppression, overcrowding, poverty, silicosis

Aetiology

Mycobacterium tuberculosis — acid-fast, aerobic, non-spore forming, slow-growing bacillus
Transmitted via airborne droplet nuclei (1–5 μm diameter) from active pulmonary TB cases
Infectious dose: very low (1–10 organisms may cause infection)
Source: coughing, sneezing, speaking, singing

Pathogenesis

Primary Infection:

Inhaled bacilli reach alveoli → engulfed by alveolar macrophages
MTB resists killing → survives and multiplies intracellularly
Cell-mediated immunity (Th1): activated CD4+ T cells → IFN-γ → activates macrophages
Granuloma formation: epithelioid macrophages + Langhans giant cells + lymphocytes surround the foci
Caseation necrosis = caseous centre (cheese-like) of granuloma
Ghon focus = primary parenchymal lesion (subpleural, lower lobe)
Ghon complex = Ghon focus + involved hilar lymph nodes + connecting lymphatics

Outcomes after Primary Infection:

90%: Latent TB — immunologically contained, bacteria dormant
10%: Progression to active disease

Post-Primary (Reactivation) TB:

Breakdown of immunity (HIV, malnutrition, steroids, aging)
Reactivation in apical/posterior upper lobes (high O₂ tension)
Cavitation, extensive destruction, highly infectious

Classification

Type	Features
Primary TB	First infection; Ghon complex; often subclinical/mild
Post-primary (Reactivation)	Cavitary upper lobe disease; adult disease
Miliary TB	Haematogenous dissemination; millet seed nodules on CXR; involves liver, spleen, meninges
Extrapulmonary TB	Lymphadenitis (most common EPTB), pleural, pericardial, spinal (Pott's), renal, meningeal

Clinical Features

Pulmonary TB:

Chronic productive cough (>2–3 weeks) — ± mucopurulent sputum
Haemoptysis — mild streaking to massive
Constitutional/B-symptoms:
- Fever (low-grade, typically afternoon/evening)
- Night sweats (drenching)
- Weight loss (>10% body weight)
- Anorexia, malaise, fatigue
Pleuritic chest pain
Progressive dyspnea (extensive disease)
"Consumption" — historical term for the wasting appearance

Physical Examination:

Apical dullness to percussion, post-tussive apical crackles
Signs of consolidation or cavity (amphoric breathing)
Cervical lymphadenopathy (in EPTB)
Signs of pleural effusion (TB pleuritis)
Wasting, pallor

Investigations

Definitive:

Sputum Acid-Fast Bacilli (AFB) smear × 3: ZN staining — red rods on blue background; cheap, rapid, but low sensitivity (~50–70%)
Sputum Culture: Gold standard for confirmation; Löwenstein-Jensen (egg) medium; takes 4–8 weeks; MGIT liquid culture — faster (2 weeks)
GeneXpert MTB/RIF (Xpert): PCR-based; detects MTB DNA and rifampicin resistance simultaneously in ~2 hours; WHO endorsed; preferred first test in many settings

Immunological: 4. Tuberculin Skin Test (TST/Mantoux): Intradermal 5 TU PPD read at 48–72 h; induration ≥10 mm positive (≥5 mm if HIV/immunocompromised); indicates infection, not active disease; BCG may cause false positives 5. IGRA (Quantiferon-TB Gold/T-SPOT): In vitro IFN-γ release; not affected by BCG; better specificity than TST

Radiological: 6. CXR:

Primary TB: hilar/paratracheal lymphadenopathy, lower/mid-zone infiltrates
Post-primary: upper lobe (apical/posterior) cavitating infiltrates, fibrosis
Miliary: bilateral fine nodular shadows ("millet seed")
Pleural effusion

Other: 7. Pleural fluid: lymphocytic exudate; ADA >40 U/L (high sensitivity for TB pleuritis); low glucose 8. BAL and bronchoscopy (smear-negative or unable to expectorate) 9. Biopsy (lymph node, pleural, liver — granulomas with caseation) 10. HIV testing in all TB patients 11. LFTs (baseline before starting treatment)

Treatment

Drug-Susceptible TB

Standard Regimen: 2HRZE / 4HR (6 months)

Phase	Duration	Drugs	Mnemonic
Intensive	2 months	Isoniazid + Rifampicin + Pyrazinamide + Ethambutol	HRZE
Continuation	4 months	Isoniazid + Rifampicin	HR

Extended to 9 months (2HRZE/7HR) if:

Cavitary disease + positive 2-month culture
2-month course of pyrazinamide not completed
Delayed sputum culture conversion

Drug side effects:

Drug	Side Effects	Notes
Isoniazid (H)	Peripheral neuropathy, hepatotoxicity, drug-induced SLE	Give pyridoxine (B6) prophylactically
Rifampicin (R)	Orange body fluids, hepatotoxicity, enzyme inducer	Reduces OCP, warfarin, antiretroviral efficacy
Pyrazinamide (Z)	Hyperuricemia, gout, hepatotoxicity, arthralgia	Check uric acid; contraindicated in gout
Ethambutol (E)	Optic neuritis → visual acuity + colour vision loss	Baseline + monthly visual check; avoid in children <5 yrs

Treatment of Latent TB (LTBI)

3HP: Isoniazid + Rifapentine weekly × 12 doses — preferred regimen
Rifampicin × 4 months
Isoniazid × 6–9 months (older standard)

MDR-TB

Definition: Resistant to isoniazid AND rifampicin
Treatment: 18–24 months with bedaquiline, linezolid, clofazimine ± others
XDR-TB: MDR + resistant to fluoroquinolones → treatment even more complex

TB/HIV Co-infection

Start TB treatment first
Initiate ART after 2–8 weeks (reduces IRIS risk)
Use efavirenz-based ART (rifampicin is an enzyme inducer)
Immune Reconstitution Inflammatory Syndrome (IRIS): paradoxical worsening of TB after ART initiation

Infection Control / Public Health

Respiratory isolation in negative pressure room (suspected/confirmed active TB)
Notification to public health authority (TB is notifiable)
Contact tracing and LTBI screening
BCG vaccine: given at birth; protects against severe childhood forms (miliary TB, TB meningitis)
Directly Observed Therapy (DOT): ensures adherence, prevents resistance

LAQ 3

Describe the aetiology, pathophysiology, clinical features, investigations, and management of CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD), including the management of an acute exacerbation.

✅ ANSWER:

CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD)

Definition

COPD is a common, preventable, and treatable disease characterized by persistent, progressive airflow limitation that is not fully reversible, caused by significant airway and/or alveolar abnormalities usually due to significant exposure to noxious particles or gases.

Aetiology / Risk Factors

Environmental:

Cigarette smoking — #1 risk factor; 85–90% of COPD
Biomass fuel (wood, charcoal, crop residue) — important in developing countries (indoor cooking)
Occupational dusts and fumes (coal, silica, cadmium, organic dusts)
Outdoor air pollution
Childhood respiratory infections / low birthweight (impaired lung development)

Genetic:

Alpha-1 antitrypsin (AAT) deficiency — autosomal recessive; panlobular emphysema in lower lobes; affects young non-smokers
Protease-antiprotease imbalance: smoking → neutrophil elastase excess → alveolar destruction

Pathology

1. Chronic Bronchitis (Large Airway Disease):

Definition: productive cough for ≥3 months/year for ≥2 consecutive years (clinical, not anatomical)
Pathology: mucus gland hypertrophy (Reid index >0.4), goblet cell metaplasia, mucociliary dysfunction
Results in: mucus hypersecretion, airway obstruction

2. Emphysema (Parenchymal Destruction):

Permanent, abnormal enlargement of airspaces distal to terminal bronchioles
Centrilobular/Centriacinar: affects respiratory bronchioles; upper lobes; caused by smoking
Panlobular/Panacinar: affects entire acinus; lower lobes; caused by α1-antitrypsin deficiency
Paraseptal: adjacent to pleura/septa; associated with spontaneous pneumothorax in young
Results in: loss of elastic recoil, air trapping, hyperinflation

3. Small Airway Disease (Bronchiolitis):

Most important site of airflow limitation in COPD
Inflammation, fibrosis, narrowing of airways <2 mm diameter

Clinical Features

Symptoms:

Chronic cough (productive — "bronchitis type")
Dyspnea: progressive, initially on exertion, later at rest
Sputum production: usually mucoid; purulent during exacerbations
Wheeze and chest tightness

Physical signs:

Prolonged expiratory phase, expiratory wheeze
Barrel chest (increased AP diameter)
Hyperresonance on percussion
Reduced diaphragmatic excursion
Use of accessory muscles (SCM, scalene)
"Tripod position" (leans forward, hands on knees)
Pursed-lip breathing
Cyanosis (lips, nail beds)
Clubbing is NOT a sign of COPD — investigate for lung cancer if present

Advanced disease:

Cachexia/weight loss (elevated TNF-α, poor intake)
Cor pulmonale: ↑JVP, peripheral edema, loud P2, RVH

Phenotypes:

"Pink Puffer" (Emphysema)	"Blue Bloater" (Chronic Bronchitis)
Thin, dyspneic, little cyanosis	Obese, cyanotic
Pursed lips, barrel chest	Productive cough, edema
↑PaO₂, normal/↓PaCO₂	↓PaO₂, ↑PaCO₂
Polycythemia absent	Polycythemia + cor pulmonale

Investigations

Spirometry (Gold Standard): FEV1/FVC <0.70 post-bronchodilator; FEV1% predicts severity
CXR: hyperinflation, flattened diaphragms, increased retrosternal space, bullae, narrow heart
CT chest: emphysema type and extent; detects lung cancer
ABG: type 2 respiratory failure — ↓PaO₂, ↑PaCO₂; compensated respiratory acidosis (↑HCO₃)
FBC: polycythemia (secondary to chronic hypoxia)
ECG/Echo: RVH, RAE, P pulmonale (peaked P waves in lead II); cor pulmonale on Echo
Sputum culture: during exacerbations (H. influenzae, S. pneumoniae, M. catarrhalis, P. aeruginosa)
Serum alpha-1 antitrypsin level — if <45 years, non/light smoker, lower lobe emphysema

GOLD Severity Classification (FEV1 % predicted post-BD):

Grade	Severity	FEV1%
GOLD 1	Mild	≥80%
GOLD 2	Moderate	50–79%
GOLD 3	Severe	30–49%
GOLD 4	Very Severe	<30%

BODE Index (predicts mortality better than FEV1 alone): BMI + airflow Obstruction + Dyspnea (MRC) + Exercise capacity (6MWT)

Management of STABLE COPD

A. Non-Pharmacological:

Smoking cessation — MOST important; slows FEV1 decline
Pulmonary rehabilitation: exercise training + education → improves QoL and reduces exacerbations
Vaccinations: annual influenza + pneumococcal (PCV13 + PPSV23) vaccines
Nutritional support (underweight patients)
Avoid occupational/environmental exposures

B. Pharmacological (GOLD ABCD groups, stepwise):

GOLD Group	Features	Preferred Initial Treatment
A (low risk, low symptoms)	Few symptoms, ≤1 exacerbation/yr, no hospitalization	SABA or SAMA PRN
B (low risk, high symptoms)	Many symptoms, ≤1 exacerbation	LABA or LAMA
E (high risk)	≥2 exacerbations or ≥1 hospitalization	LABA + LAMA; add ICS if eos ≥300

SABA: Salbutamol, terbutaline (rescue)
SAMA: Ipratropium (rescue)
LABA: Salmeterol, formoterol (maintenance)
LAMA: Tiotropium (once daily — best single agent; reduces exacerbations, hospitalizations)
ICS: Fluticasone, budesonide — add only with LABA in frequent exacerbators with eos ≥300; risk of pneumonia
Roflumilast (PDE-4 inhibitor): add for GOLD 3–4 + chronic bronchitis + frequent exacerbations (reduces exacerbations)
Azithromycin (macrolide): add-on for recurrent exacerbators (non-smokers preferred)
Theophylline: last resort; narrow therapeutic window

C. Long-Term Oxygen Therapy (LTOT):

PaO₂ ≤55 mmHg (or SpO₂ ≤88%) at rest on 2 separate occasions ≥3 weeks apart
OR PaO₂ 56–59 mmHg with cor pulmonale, polycythemia, or pulmonary hypertension
Goal: >15 hours/day; target PaO₂ >60 mmHg; SpO₂ 88–92%
Only treatment shown to improve survival (alongside smoking cessation)

D. Surgical Options:

Lung volume reduction surgery (LVRS): selected emphysema (upper lobe predominant)
Bullectomy: giant bullae causing compression
Lung transplant: very severe COPD (GOLD 4), young patients, BODE score ≥7

Management of ACUTE EXACERBATION OF COPD (AECOPD)

Definition: Acute worsening of respiratory symptoms (dyspnea ↑, sputum ↑, sputum purulence) beyond normal day-to-day variation, requiring change in medication.

Triggers: Viral URTI (most common — rhinovirus, RSV), bacterial (H. influenzae, S. pneumoniae, M. catarrhalis), air pollution

Management:

Controlled O₂: Venturi mask 24–28% FiO₂; target SpO₂ 88–92% — NEVER high-flow in known/suspected CO₂ retainers
Bronchodilators: Nebulized salbutamol (2.5–5 mg) + ipratropium (0.5 mg) every 4–6 hours
Systemic corticosteroids: Prednisolone 30–40 mg orally for 5 days
Antibiotics: if increased sputum purulence/volume OR fever:
- 1st line: Amoxicillin 500 mg TDS OR Doxycycline 200 mg OD
- 2nd line: Co-amoxiclav OR Clarithromycin
- Severe/Pseudomonas risk: Ciprofloxacin
Non-Invasive Ventilation (NIV/BiPAP): First-line for type 2 RF
- Indication: pH <7.35 AND PaCO₂ >6 kPa DESPITE optimal medical therapy
- Reduces intubation rate and mortality
- IPAP 12–20 cmH₂O; EPAP 4–5 cmH₂O; titrate by ABG response
Invasive Ventilation: if NIV fails, pH <7.25, hemodynamic instability, unable to protect airway
DVT prophylaxis: LMWH (enoxaparin) + compression stockings
Monitor: ABG every 30–60 min initially; U&E, FBC, CXR, ECG, sputum culture

Discharge criteria:

Stable on inhaler therapy (not requiring nebulizer >4 hourly)
Clinically stable for >24 hours
Adequate community support

Prognosis

COPD is the 3rd leading cause of death worldwide
Predictors of mortality: BODE index, FEV1, exacerbation frequency, comorbidities
Only two interventions improve survival: Smoking cessation and LTOT

SUMMARY TABLE: HIGH-YIELD EXAM FACTS

Topic	Key Point
Asthma reversibility	≥12% + ≥200 mL FEV1 improvement post-SABA
COPD diagnosis	FEV1/FVC <0.70 post-bronchodilator
TB regimen	2HRZE / 4HR (6 months)
Ethambutol toxicity	Optic neuritis — monitor visual acuity + colour
Isoniazid toxicity	Peripheral neuropathy — give pyridoxine (B6)
Rifampicin	Orange body fluids + enzyme inducer
Light's criteria exudate	Protein >0.5, LDH >0.6, LDH >2/3 ULN
CURB-65 ≥3	Severe CAP — hospitalize + IV antibiotics
AECOPD + pH <7.35	NIV (BiPAP) — first-line
COPD O₂ target	88–92% (controlled)
Asthma O₂ target	94–98% (high flow)
Tension pneumothorax	Clinical diagnosis — immediate needle decompression
PE gold standard	CTPA
ARDS tidal volume	6 mL/kg ideal body weight
Legionella diagnosis	Urinary antigen
SCLC paraneoplastic	SIADH (hyponatremia), Cushing's (ACTH), Eaton-Lambert
SCC paraneoplastic	Hypercalcemia (PTHrP)
Clubbing in COPD	NOT normal — investigate for lung cancer
Kartagener's	Bronchiectasis + sinusitis + situs inversus
ADA >40 U/L pleural	Tuberculous pleuritis

Sources: Harrison's Principles of Internal Medicine 22E (2025); Murray & Nadel's Textbook of Respiratory Medicine; Goldman-Cecil Medicine

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