OSCE — assessment of suspected pulmonary tuberculosis · MBBS OSCE

Brief (to candidate)

A 40-year-old man presents to the outpatient department with a 4-week productive cough, streaky haemoptysis, night sweats and 5 kg weight loss. He is diabetic. Chest X-ray shows right upper-lobe cavitation. You have 8 minutes to assess him, confirm the diagnosis, state the treatment regimen with doses, and outline the public-health measures. ^[1]

Candidate instructions

Take a focused history and examine, using an ABCDE approach.
State how you would confirm the diagnosis and the infection-control reflex.
Outline the treatment regimen with weight-based doses and monitoring for toxicity.
State the public-health measures (isolation, HIV testing, notification, contact screening).^[11]

Examiner checklist (mark each domain / 10)

Domain	Key actions expected
Infection control FIRST	Recognises open pulmonary TB risk → airborne isolation (negative-pressure room, N95/FFP2)^[11]
Confirmation	Xpert MTB/RIF as the rapid molecular test (Boehme: 98.2% smear-positive / 72.5% smear-negative, less than 2 hours, also rifampicin resistance), plus AFB smear and culture; HIV test^[4]
Diagnosis & differential	Reactivation pulmonary TB; lung cancer, abscess, fungal infection, sarcoidosis^[1]
Regimen with doses	WHO 2HRZE/4HR; ATS INH 5 mg/kg (typically 300 mg), RIF 10 mg/kg (typically 600 mg), pyridoxine 25–50 mg/day if neuropathy-risk (diabetes here)^[3]^[11]
Toxicity monitoring	LFTs; ALT ≥3× ULN with symptoms or ≥5× without → stop hepatotoxic drugs; visual change → stop ethambutol; rifampicin orange secretions + CYP450 induction^[3]
Public health	Notify (Ni-kshay), contact screening, isolate until non-infectious^[11]
Communication & safety-net	Adherence; if rifampicin-resistant → WHO 6-month BPaLM if eligible

Model key actions

Isolate airborne first — do not examine further in an open bay.^[11]
Xpert MTB/RIF on sputum as the rapid test; smear + culture; HIV test.^[4]
6-month 2HRZE/4HR with ATS adult INH/RIF typical doses and pyridoxine 25–50 mg/day; monitor LFTs and vision.^[3]
Notify (Ni-kshay), contact-screen, isolate until non-infectious.^[11]

Common errors

Examining the patient in an open area without airborne isolation.
Using smear alone and not sending Xpert — delays rifampicin-resistance detection.
Stating "anti-TB drugs" with no regimen structure, or no pyridoxine despite diabetes.
Inventing PZA max 2 g / EMB 15–20 mg/kg as if they were the ATS table (they are weight-banded).
Forgetting to test HIV, notify or contact-screen.^[3]^[4]

References5Show

[1]Pai M, Behr MA, Dowdy D, et al. Tuberculosis. Nature Reviews Disease Primers, 2016.PMID 27784885
[3]Nahid P, Dorman SE, Alipanah N, et al. Official American Thoracic Society/Centers for Disease Control and Prevention/Infectious Diseases Society of America Clinical Practice Guidelines: Treatment of Drug-Susceptible Tuberculosis Clinical Infectious Diseases, 2016.PMID 27516382
[4]Boehme CC, et al. Rapid molecular detection of tuberculosis and rifampin resistance. New England Journal of Medicine, 2010.PMID 20825313
[9]Nahid P, Dorman SE, Alipanah N, et al. Official American Thoracic Society/Centers for Disease Control and Prevention/Infectious Diseases Society of America Clinical Practice Guidelines: Treatment of Drug-Susceptible Tuberculosis Clin Infect Dis, 2016.PMID 27516382
[11]World Health Organization WHO consolidated guidelines on tuberculosis. Module 4: treatment and care World Health Organization, 2025.Source

Brief (to candidate)

Candidate instructions

Take a focused history and examine, using an ABCDE approach.

State how you would confirm the diagnosis and the infection-control reflex.

Outline the treatment regimen with weight-based doses and monitoring for toxicity.

State the public-health measures (isolation, HIV testing, notification, contact screening).^[11]

Examiner checklist (mark each domain / 10)

Domain	Key actions expected
Infection control FIRST	Recognises open pulmonary TB risk → airborne isolation (negative-pressure room, N95/FFP2)^[11]
Confirmation	Xpert MTB/RIF as the rapid molecular test (Boehme: 98.2% smear-positive / 72.5% smear-negative, less than 2 hours, also rifampicin resistance), plus AFB smear and culture; HIV test^[4]
Diagnosis & differential	Reactivation pulmonary TB; lung cancer, abscess, fungal infection, sarcoidosis^[1]
Regimen with doses	WHO 2HRZE/4HR; ATS INH 5 mg/kg (typically 300 mg), RIF 10 mg/kg (typically 600 mg), pyridoxine 25–50 mg/day if neuropathy-risk (diabetes here)^[3]^[11]
Toxicity monitoring	LFTs; ALT ≥3× ULN with symptoms or ≥5× without → stop hepatotoxic drugs; visual change → stop ethambutol; rifampicin orange secretions + CYP450 induction^[3]
Public health	Notify (Ni-kshay), contact screening, isolate until non-infectious^[11]
Communication & safety-net	Adherence; if rifampicin-resistant → WHO 6-month BPaLM if eligible

Model key actions

Isolate airborne first — do not examine further in an open bay.^[11]

Xpert MTB/RIF on sputum as the rapid test; smear + culture; HIV test.^[4]

6-month 2HRZE/4HR with ATS adult INH/RIF typical doses and pyridoxine 25–50 mg/day; monitor LFTs and vision.^[3]

Notify (Ni-kshay), contact-screen, isolate until non-infectious.^[11]

Common errors

Examining the patient in an open area without airborne isolation.

Using smear alone and not sending Xpert — delays rifampicin-resistance detection.

Stating "anti-TB drugs" with no regimen structure, or no pyridoxine despite diabetes.

Inventing PZA max 2 g / EMB 15–20 mg/kg as if they were the ATS table (they are weight-banded).

Forgetting to test HIV, notify or contact-screen.^[3]^[4]

References5Show

[1]Pai M, Behr MA, Dowdy D, et al. Tuberculosis. Nature Reviews Disease Primers, 2016.PMID 27784885
[3]Nahid P, Dorman SE, Alipanah N, et al. Official American Thoracic Society/Centers for Disease Control and Prevention/Infectious Diseases Society of America Clinical Practice Guidelines: Treatment of Drug-Susceptible Tuberculosis Clinical Infectious Diseases, 2016.PMID 27516382
[4]Boehme CC, et al. Rapid molecular detection of tuberculosis and rifampin resistance. New England Journal of Medicine, 2010.PMID 20825313
[9]Nahid P, Dorman SE, Alipanah N, et al. Official American Thoracic Society/Centers for Disease Control and Prevention/Infectious Diseases Society of America Clinical Practice Guidelines: Treatment of Drug-Susceptible Tuberculosis Clin Infect Dis, 2016.PMID 27516382
[11]World Health Organization WHO consolidated guidelines on tuberculosis. Module 4: treatment and care World Health Organization, 2025.Source