MBBS 3rd Professional (Part-2) Medicine Paper-I — Complete Answers from Harrison's Principles of Internal Medicine (21st Ed.)

SECTION A — MCQs (20 Marks)

SECTION B — Long Answers (40 Marks)

Q1. 45-year-old male, smoker, hematemesis + melena, splenomegaly + caput medusae

• Splenomegaly + caput medusae = portal hypertension
• Chronic smoking → hepatotoxicity; hematemesis + melena = esophageal variceal bleeding

1. Resuscitate: IV access, cross-match, transfuse pRBCs (target Hb 7-8 g/dL - restrictive strategy)
2. Vasoactive drugs: IV Terlipressin (drug of choice) or Octreotide/Somatostatin immediately - reduce splanchnic blood flow
3. Antibiotics: IV Ceftriaxone 1g/day × 5-7 days (reduces bacterial translocation, improves survival)
4. Endoscopy (within 12 hours): Endoscopic variceal ligation (EVL) - treatment of choice > sclerotherapy
5. Balloon tamponade (Sengstaken-Blakemore tube): if endoscopy unavailable/bleeding uncontrolled - temporary bridge
6. TIPS (Transjugular Intrahepatic Portosystemic Shunt): if uncontrolled/rebleeding

• Recurrent variceal bleeding
• Hepatic encephalopathy
• Spontaneous bacterial peritonitis (SBP)
• Hepatorenal syndrome
• Hepatopulmonary syndrome / portopulmonary hypertension
• Hepatocellular carcinoma (HCC)
• Coagulopathy, thrombocytopenia

• Avoid precipitants: GI bleeding, infections, constipation, benzodiazepines, high protein intake
• Lactulose (titrated to 2-3 soft stools/day) - acidifies colon, reduces ammonia absorption
• Rifaximin 550mg BD - non-absorbable antibiotic, secondary prophylaxis
• Zinc supplementation (cofactor for urea cycle enzymes)
• Treat SBP promptly; adequate nutrition (do NOT restrict protein)

Q2(a). Thyroid Storm - Clinical Features & Management

• Fever >38.5°C (up to 41°C), profuse sweating
• Tachycardia >140 bpm, AF, cardiac failure
• Agitation, delirium, psychosis, coma
• Vomiting, diarrhea, jaundice (severe)
• Burch-Wartofsky Point Scale (BWPS) ≥45 = thyroid storm

1. Beta-blocker: Propranolol IV/oral (blocks peripheral T4→T3 conversion + sympathetic effects) - FIRST and fastest acting
2. Thionamide: PTU 500-1000mg loading then 250mg q4h (PTU preferred over MMI - also blocks T4→T3 conversion)
3. Iodine (Lugol's/SSKI) - given 1 hour AFTER PTU (blocks hormone release - Wolff-Chaikoff effect)
4. Glucocorticoids: Hydrocortisone 300mg IV then 100mg q8h (blocks T4→T3, treats relative adrenal insufficiency)
5. Supportive: IV fluids, cooling blankets (avoid aspirin - displaces T4 from TBG), treat precipitant

Q2(b). Inflammatory Bowel Disease (IBD)

• Mild-moderate UC: 5-ASA (mesalazine) topical/oral
• Moderate-severe: Corticosteroids (acute); Azathioprine/6-MP (maintenance)
• Biologics: Anti-TNF (infliximab, adalimumab); vedolizumab, ustekinumab
• Surgery: Colectomy (UC, medically refractory); resection (Crohn's - not curative)

Q2(c). Adrenal Insufficiency (Addison's Disease)

• Primary (Addison's): Autoimmune (80% in developed world) - anti-21-hydroxylase antibodies; TB (most common worldwide); bilateral adrenal hemorrhage (Waterhouse-Friderichsen)
• Secondary: Pituitary (ACTH deficiency); Tertiary: Hypothalamic; Iatrogenic (steroid withdrawal)

• Chronic: Fatigue, weight loss, anorexia, nausea, postural hypotension, salt craving
• Hyperpigmentation (increased ACTH/MSH cross-reactivity) - buccal mucosa, palmar creases, scars - primary only
• Hyponatremia, hyperkalemia, mild acidosis (mineralocorticoid deficiency)
• Hypoglycemia (glucocorticoid deficiency)
• Adrenal crisis: Hypotension, vomiting, abdominal pain, fever, shock - life-threatening

• Serum cortisol 8am (low <3 µg/dL diagnostic; >18 µg/dL rules out)
• ACTH stimulation test (Synacthen test): Gold standard - cortisol fails to rise to >18-20 µg/dL at 30-60 min
• ACTH level: high in primary, low/normal in secondary

• Chronic: Hydrocortisone 15-25mg/day in divided doses (2/3 morning, 1/3 afternoon); Fludrocortisone 0.05-0.1mg/day (mineralocorticoid - primary only)
• Crisis: IV hydrocortisone 100mg bolus → 50-100mg q6-8h; IV fluids (normal saline + dextrose); treat precipitant
• Sick day rules: double dose during illness

Q2(d). Management of Acute MI in First Hour (Golden Hour)

• ECG within 10 minutes of arrival, cardiac enzymes (troponin), O₂ if SpO₂ <90%

1. Morphine 2-4mg IV (pain relief, reduces sympathetic activation) - use cautiously
2. Oxygen - only if SpO₂ <90%
3. Nitrates - sublingual/IV (contraindicated if RV infarct, hypotension, PDE5 inhibitor use)
4. Aspirin 325mg loading dose stat (irreversible COX-1 inhibition)
5. P2Y12 inhibitor: Ticagrelor 180mg or Clopidogrel 300-600mg loading
6. Anticoagulation: Heparin (UFH/LMWH)
7. Beta-blocker: Oral (if no acute HF, bradycardia, hypotension)

• Primary PCI (preferred, "door-to-balloon" <90 min) - gold standard for STEMI
• Thrombolysis (streptokinase/tPA) if PCI not available within 120 min - "door-to-needle" <30 min
• For NSTEMI: risk stratify → urgent PCI within 24 hours for high-risk

SECTION C — Long Answers (40 Marks)

C-Q1. 24-year-old female, malar rash, joint pain, photosensitivity, 3+ proteinuria

1. ANA (Antinuclear Antibody) - screening test, sensitivity >95%; if positive, proceed to:
2. Anti-dsDNA - specific for SLE (70%), correlates with disease activity/renal involvement
3. Anti-Sm (Smith) - most specific for SLE (~30% sensitive, ~99% specific)
4. Complement levels: C3, C4 (low in active SLE - immune complex consumption)
5. Anti-Ro/SSA, Anti-La/SSB (neonatal lupus, secondary Sjogren's)
6. Anti-phospholipid antibodies (aCL, anti-β2GPI, lupus anticoagulant)
7. Direct Coombs test (hemolytic anemia)

• Skin: Malar rash (butterfly), discoid lupus, photosensitivity, oral ulcers, alopecia
• Joints: Non-erosive polyarthritis (Jaccoud's arthropathy)
• Renal: Lupus nephritis (3+ proteinuria → class III/IV most likely); hematuria, hypertension, CKD
• Hematological: Hemolytic anemia, leukopenia, lymphopenia, thrombocytopenia
• Neuropsychiatric: Psychosis, seizures, CVA (NPSLE)
• Cardiac: Pericarditis, Libman-Sacks endocarditis
• Pulmonary: Pleuritis, pneumonitis, pulmonary hypertension

• Renal biopsy to classify (ISN/RPS: Class I-VI)
• Class III/IV (proliferative - most severe):
  • Induction: High-dose corticosteroids (pulse methylprednisolone 500-1000mg × 3 days → oral prednisolone 0.5-1mg/kg/day) + Mycophenolate mofetil (MMF) 2-3g/day (preferred over cyclophosphamide now) or IV cyclophosphamide
  • Maintenance: MMF 1-2g/day or azathioprine + low-dose prednisolone
• Hydroxychloroquine (antimalarial) - all SLE patients (renal protective, reduces flares)
• ACE inhibitor/ARB - for proteinuria control and renoprotection
• Belimumab (anti-BLyS biologic) - approved add-on for active SLE
• Voclosporin or anifrolumab - newer agents for lupus nephritis
• Monitor: urine protein/creatinine ratio, anti-dsDNA, complement levels, BP, eGFR

SECTION C — Short Notes

C-Q2(a). Megaloblastic Anemia - Pathogenesis & Management

• Deficiency of Vitamin B12 or Folate → impaired DNA synthesis (thymidylate synthesis requires methyleneTHF; B12 needed to regenerate THF)
• Cells cannot divide properly → nuclear-cytoplasmic asynchrony → large cells (megaloblasts in marrow, macrocytes in blood)
• Ineffective erythropoiesis → intramedullary hemolysis → raised LDH, bilirubin

• B12 deficiency: IM Hydroxocobalamin 1000µg daily × 7 days → weekly × 4 → monthly (for pernicious anemia/malabsorption); oral B12 1-2mg/day (if dietary)
• Folate deficiency: Folic acid 5mg/day PO × 4 months
• Always replace B12 before/with folate (giving folate alone in B12 deficiency can precipitate subacute combined degeneration of cord)

C-Q2(b). Ascites in Cirrhosis - Etiology & Management

• Dietary Na restriction (<2g/day) + fluid restriction (if Na <125)
• Diuretics: Spironolactone 100-400mg/day (aldosterone antagonist) ± Furosemide 40-160mg/day (ratio 100:40)
• Large volume paracentesis (LVP) for tense ascites → albumin 6-8g per liter removed (prevents circulatory dysfunction)
• TIPS for refractory ascites
• SBP prophylaxis: Norfloxacin/Ciprofloxacin if ascitic PMN >250, previous SBP, or variceal bleed

C-Q2(c). Immune Thrombocytopenic Purpura (ITP)

• Isolated thrombocytopenia (plt <100 × 10⁹/L), normal WBC/Hb
• Peripheral smear: decreased platelets, large platelets (megathrombocytes), normal morphology
• Exclude: HIV, HCV, SLE, drug-induced, lymphoma
• Bone marrow: increased megakaryocytes (if biopsy done in atypical cases)
• Anti-platelet antibodies (IgG anti-GPIIb/IIIa) - not routinely used

• Plt >30 + asymptomatic: observe
• First line: Oral prednisolone 1mg/kg/day × 3-4 weeks
• IV Ig 1g/kg × 2 days (rapid rise in 24-48h; for bleeding/surgery)
• Anti-D immunoglobulin (Rh+ve, non-splenectomized)
• Second line: Splenectomy (durable remission ~60%); TPO-receptor agonists (eltrombopag, romiplostim)
• Refractory: Rituximab, fostamatinib, dapsone

C-Q2(d). Palliative Care & Medical Ethics in Terminal Illness

• Relief of pain and symptoms (WHO analgesic ladder; opioids for severe pain)
• Psychological, social, and spiritual support for patient AND family
• Neither hastens nor postpones death
• Symptom control: Dyspnea (morphine/anxiolytics), nausea (metoclopramide), constipation (opioid-induced)

1. Autonomy - Respect patient's informed decision; advance directives
2. Beneficence - Act in patient's best interest
3. Non-maleficence - Avoid harm; do not pursue futile interventions
4. Justice - Fair allocation of resources

SECTION C — Very Short Notes

C-Q3(a). Laboratory Diagnosis of Multiple Myeloma

• Serum/urine protein electrophoresis → monoclonal (M) spike (IgG most common, then IgA)
• Serum free light chains (kappa/lambda ratio)
• Urine: Bence Jones protein (free light chains - nephrotoxic)
• Bone marrow biopsy: >10% clonal plasma cells (diagnostic criterion)
• Skeletal survey/PET-CT: lytic "punched-out" lesions
• CBC: normocytic anemia, rouleaux formation
• Raised serum calcium, creatinine, LDH, β2-microglobulin (prognostic)

C-Q3(b). Type 1 vs Type 2 DM

C-Q3(c). Causes of Generalized Lymphadenopathy

• Infections: EBV (infectious mononucleosis), CMV, HIV, TB, brucellosis, secondary syphilis, toxoplasmosis
• Malignancies: Lymphoma (Hodgkin's and NHL), CLL, acute leukemia, metastatic carcinoma
• Autoimmune: SLE, RA, Sjogren's, sarcoidosis
• Drugs: Phenytoin, allopurinol, carbamazepine
• Miscellaneous: Serum sickness, amyloidosis, Castleman disease

C-Q3(d). Treatment of Status Epilepticus

• 0-5 min: Stabilize - ABC, glucose, IV access, thiamine
• 5-20 min (Phase 1 - Benzodiazepine): Lorazepam 0.1mg/kg IV (preferred); or Diazepam 0.15mg/kg IV; or IM Midazolam 0.2mg/kg (if no IV access)
• 20-40 min (Phase 2 - 2nd agent): IV Levetiracetam 60mg/kg (preferred now per Established SE Trial) or Phenytoin/Fosphenytoin 20mg/kg or Valproate 40mg/kg
• >40 min (Refractory SE): ICU intubation + anesthetic doses: Propofol, Midazolam, Thiopental infusion; continuous EEG monitoring

C-Q3(e). Components of Metabolic Syndrome (IDF/ATP-III criteria)

1. Abdominal obesity - waist >102cm (M), >88cm (F); IDF: >90cm Asian M, >80cm Asian F
2. Hypertriglyceridemia - TG ≥150 mg/dL
3. Low HDL - <40 mg/dL (M), <50 mg/dL (F)
4. Hypertension - BP ≥130/85 mmHg or on treatment
5. Fasting hyperglycemia - FBG ≥100 mg/dL or T2DM

Note on Q4 (Conn's Syndrome): The correct electrolyte profile is Hypokalemia + Metabolic ALKALOSIS (not acidosis). If option (d) in the paper states "Hyperkalemia and Metabolic Acidosis" that would be Addison's disease. The intended correct answer for Conn's is whichever option states Hypokalemia - per Harrison's, aldosterone excess causes Na⁺ retention, K⁺ wasting (hypokalemia), and H⁺ secretion (metabolic alkalosis) with hypertension and suppressed renin.