MPMSU Medicine 2019 question paper 2 with answers

1.CLINICAL FEATURES OF H1N1 INFLUENZA

H1N1 influenza presents similarly to seasonal flu.

(a) Common Symptoms:
• Fever and chills
• Fatigue
• Cough and sore throat
• Headache and body aches
• Digestive symptoms: diarrhea and vomiting

(b) Clinical Deterioration:
• Primary viral pneumonia (destroys lung tissue, not responsive to antibiotics)
• Multiorgan dysfunction (heart, kidneys, liver)
• Severe disease symptoms include:
– Dyspnea
– Cyanosis
– Dehydration
– Altered mental status

2. DIAGNOSIS

• Real-time RT-PCR is the recommended test for confirmation of H1N1 cases.
• Sample taken from nose or throat swab.

3. COMPLICATIONS

(A) Pulmonary Complications

Most commonly due to secondary bacterial superinfection by:

• Streptococcus pneumoniae
• Staphylococcus aureus
• Other bacterial pathogens

May lead to:
• Severe pneumonia
• Respiratory failure
• ARDS

(B) Rare Extrapulmonary Manifestations

Musculoskeletal: Myositis

Cardiac: Myocarditis, Pericarditis

Neurological:
• Reye’s syndrome (typically in children, especially with aspirin use)
• Encephalitis
• Transverse myelitis

4. MANAGEMENT

1. Supportive Therapy

(a) Isolate the patient to prevent transmission.
(b) Provide bed rest, plenty of fluids, cough suppressants, antipyretics, and analgesics
    (e.g., acetaminophen, NSAIDs) for fever and muscle pain.
(c) Severe cases may require:
• IV hydration
• Ventilator support

2. Antiviral Treatment

(a) Used for serious or high-risk patients.

First-line drugs:
• Oseltamivir (Tamiflu) → 75 mg twice daily for 5 days
• Zanamivir → 10 mg inhaled twice daily for 5 days

(b) Best started within 48 hours of symptom onset.
(c) Action → Inhibit neuraminidase, reducing viral release & spread.
(d) Helps reduce risk of pneumonia & hospitalization.
(e) High-risk groups (pregnancy, underlying illness) should receive antivirals immediately — even before lab confirmation.

3. Preventing Spread of Infection

(a) Self-isolate for 7 days after symptoms begin or 24 hours after recovery.

(b) Infection control measures:
• Frequent handwashing with soap and water
• Use face mask, especially within 6 feet of others or while visiting healthcare
• Call physician before hospital/clinic visit

(c) Antiviral prophylaxis for high-risk contacts:
• Household contacts with chronic illness, pregnancy, age <5 or >65
• High-risk school children
• Healthcare workers exposed without protection

(d) Not recommended for healthy individuals.
(e) School closures & avoiding public gatherings may be required during outbreaks.

4. Vaccination

(a) Stimulates active immunity.

Available formulations:
• Intramuscular (IM) — inactivated, 0.5 mL
• Children <10 years → 2 doses
• Adults & children ≥10 years → 1 dose
• Intranasal — live vaccine, 0.2 mL (0.1 mL/nostril)
• Quadrivalent vaccine — H1N1 + 3 other strains

(b) Recommended for pregnant women, adults & children >6 months.

CLINICAL FEATURES

A. FEATURES DUE TO HYPERGLYCEMIA

I. Earliest Symptoms
a. Polyuria
b. Polydipsia
c. Weight loss

II. Neurological Symptoms (due to ↑ osmolality)
a. Lethargy
b. Confusion or focal neurological deficits
c. Obtundation → may progress to coma

III. Visual Changes
a. Blurred vision • Due to osmotic change in lens refractive power

B. FEATURES DUE TO DEHYDRATION

I. Physical Signs
a. Reduced skin turgor
b. Dry tongue & cracked lips
c. Sunken eyeballs

II. Circulatory Features
a. Tachycardia
b. Hypotension
c. Cold extremities & peripheral cyanosis

C. FEATURES DUE TO METABOLIC ACIDOSIS

I. Respiratory
a. Deep, rapid breathing — Kussmaul respiration

II. Breath Odor
a. Fruity/acetone smell

III. GIT Symptoms
a. Nausea
b. Vomiting
c. Abdominal pain • Caused by acidosis & electrolyte imbalance

D. OTHER ASSOCIATED FEATURES

I. With Precipitating Illness
a. Fever in infections
b. Signs of pneumonia / consolidation
c. Any illness triggering metabolic disturbance

MANAGEMENT OF DKA

A. PRINCIPLES

I. Main Targets
a. Correct dehydration
b. Correct hyperglycemia
c. Correct electrolyte imbalance

II. Additional Requirements
a. Identify & treat precipitating cause
b. Frequent monitoring required

B. INITIAL ASSESSMENT

I. Clinical Evaluation
a. ABCs: Airway, Breathing, Circulation
b. Vital signs + GCS
c. IV access

II. Investigations
a. Blood glucose, electrolytes, ketones
b. ABG/VBG, BUN/Cr, ECG
c. Search cause: infection, missed insulin, MI, stroke

C. FLUID RESUSCITATION (FIRST & MOST IMPORTANT)

I. Initial Fluid
a. Start 0.9% Normal Saline — 1L in first hour (adjust to BP/hydration)

II. After Stabilization
a. Shift to 0.45% saline if sodium high/normal

III. When Glucose Reaches 200–250 mg/dL
a. Add 5–10% dextrose • Prevents hypoglycemia while ketosis resolves

D. INSULIN THERAPY

I. Start After Checking Potassium
a. IV regular insulin 0.1 units/kg/hr continuous infusion

II. Target
a. Reduce glucose 50–75 mg/dL per hour

III. Continue Until
a. pH > 7.3
b. HCO₃⁻ > 18
c. Anion gap normalizes • Not just when glucose normalizes

E. POTASSIUM REPLACEMENT

I. Indications
a. Start only if K⁺ < 5.3 mEq/L
b. If K⁺ < 3.3 → hold insulin, give K⁺ first

II. Target
a. Maintain K⁺ 4–5 mEq/L • Continuous ECG monitoring advised

F. BICARBONATE THERAPY

I. Indication
a. Only if pH < 6.9 • Not routinely recommended

G. TREAT UNDERLYING CAUSE

I. Common Triggers
a. Infection (UTI/Pneumonia)
b. Missed or inadequate insulin dose
c. MI/Stroke/Pancreatitis
d. New onset diabetes

H. MONITORING

I. Regular Assessment
a. Hourly glucose
b. Electrolytes + ABG/VBG every 2–4 hrs
c. Urine output + fluid balance
d. Mental status
e. Watch for cerebral edema (especially in children)

AETIOLOGY

Post-infectious glomerulonephritis (most common – Post-streptococcal)

• Occurs after Group A β-hemolytic Streptococcal throat or skin infection.
• Other causes: Hepatitis B, Hepatitis C, HIV, CMV, Syphilis, Malaria, SBE, Infectious Mononucleosis.

Primary Glomerular Diseases

• Diffuse Proliferative GN
• Membranoproliferative GN (MPGN)
• Rapidly Progressive / Crescentic GN (RPGN)
• IgA Nephropathy

Secondary to Systemic Diseases

• SLE
• ANCA-associated vasculitis
• Goodpasture Syndrome (Anti-GBM)
• Henoch–Schönlein Purpura (IgA Vasculitis)
• Polyarteritis Nodosa

Others

• Serum sickness, Malignant HTN, Eclampsia, Malignancy, Drug-induced

PATHOGENESIS

Mostly immune-mediated.

1. In situ Antibody Deposition

• Antibodies against GBM (e.g., Goodpasture disease)

2. Circulating Immune Complex Deposition

• Classic in Post-streptococcal GN (Type III Hypersensitivity).
• → Complement activation → ↓C3
• → Cytokine release & neutrophil influx
• → Glomerular damage → ↓GFR

CLINICAL FEATURES

Common in children 5–15 yrs, more in boys.

Features of Nephritic Syndrome

• Hematuria — cola/tea-colored urine, RBC casts
• Proteinuria — mild/moderate (<3g/day)
• Oliguria — reduced urine output
• Edema — periorbital → generalized
• Hypertension — due to fluid retention

Associated symptoms:

• Fever, malaise, anorexia, headache, flank pain
• Subclinical cases → microscopic hematuria only

Investigations

• ↓Complement C3 (normalizes in 6–8 weeks)
• ↑ASO titre in Post-streptococcal GN
• Urine: RBC casts, pyuria, mild proteinuria
• ↑Serum Creatinine, ↑Urea

MANAGEMENT

Supportive Treatment

• Salt & fluid restriction
• Diuretics (Furosemide) for edema
• Antihypertensives (ACEI/CCB)
• Dialysis if severe renal failure/hyperkalemia/pulmonary edema

If Streptococcal infection suspected

• Treat patient + close contacts
• Penicillin V/Amoxicillin 10 days
• (Alternatives: Cephalosporins, Macrolides, Clindamycin)

Immunosuppressive Therapy

• Not used in typical PSGN
• Indicated in RPGN, SLE, Anti-GBM disease

PROGNOSIS

• Excellent in children — complete recovery within weeks
• Microscopic hematuria may persist months
• CKD is uncommon

PATHOGENESIS

Acute rheumatic fever is a delayed immune-mediated response to Group A Streptococcal infection. Streptococcal antigens cross-react with cardiac myosin and sarcolemmal proteins, leading to autoimmune inflammation of endocardium, myocardium, pericardium, joints and skin.

Histology: fibrinoid degeneration in connective tissues; Aschoff nodules (pathognomonic) seen only in heart → multinucleated giant cells, macrophages and T-lymphocytes.

DIAGNOSIS

Jones Criteria

Major manifestations:

• Carditis
• Polyarthritis
• Chorea
• Erythema marginatum
• Subcutaneous nodules

Minor manifestations:

• Fever
• Arthralgia
• Raised ESR/CRP
• Previous rheumatic fever
• Leucocytosis
• First-degree AV block

Plus — evidence of preceding streptococcal infection:
Recent scarlet fever, ↑ASO/streptococcal antibodies, positive throat culture.

Diagnosis requires: 2 major OR 1 major + 2 minor with evidence of streptococcal infection.

LABORATORY FINDINGS

• Mild normocytic normochromic anemia
• Polymorphonuclear leukocytosis
• Elevated ESR, CRP

Evidence of Streptococcal Infection:

• ASO, anti-DNase B, antihyaluronidase, antistreptozyme test
• ASO ↑ in ≥80% patients (Adults >200 Todd units/ml, Children >320).
• Rising titres more significant.

ECG

• Persistent sinus tachycardia
• PR interval prolongation
• AV conduction defects, atrial flutter/fibrillation
• Low QRS voltage if pericardial effusion present

Echocardiography

• Mitral valvulitis, annular dilation
• Thickened valves, nodular lesions
• Mitral regurgitation
• Heart failure

ENDOMYOCARDIAL BIOPSY

Limited role. Shows Aschoff nodules, interstitial mononuclear infiltrates, myocyte necrosis.

MANAGEMENT

Acute Episode
Strict bed rest until fever, ESR, pulse & ECG normalize.

Management of Heart Failure

• Diuretics, ACE inhibitors, beta-blockers
• Digoxin cautious in myocarditis
• Mitral valve repair/replacement if severe

Antibiotics (eradicate residual streptococci)

• Benzathine penicillin G 1.2 million units IM single dose
• Phenoxymethylpenicillin 250 mg QID × 10 days
• If allergic: erythromycin / cephalosporins

Prophylaxis (prevent recurrence)

• Phenoxymethylpenicillin 250 mg BID
• OR Benzathine penicillin G 1.2 million units IM monthly
• If allergic → sulfadiazine or erythromycin

Prophylaxis duration:
Usually stop at age 21.
Continue longer if recent attack (<5 yrs), high exposure risk, or residual heart disease (up to age 40 or 10 yrs after last attack).

Aspirin

• Symptomatic relief within 24 hrs
• Dose: 60 mg/kg/day in divided doses (adult up to 100 mg/kg/day)
• Toxicity: nausea, tinnitus, deafness; severe → vomiting, acidosis
• Continue until ESR normal, then taper

Glucocorticoids

• Indicated in carditis or severe arthritis
• Prednisolone 1–2 mg/kg/day
• Taper when ESR normal
• Provides rapid improvement, no long-term benefit