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📋 APPENDICITIS - EXAM NOTES

(A Concise Textbook of Surgery)

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1. TYPES OF APPENDICITIS

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2. ACUTE APPENDICITIS

INCIDENCE ⭐

• Most common acute surgical condition of abdomen
• Peak: 2nd and 3rd decades of life
• More common in teenage girls
• Rare in children (lumen configuration makes obstruction unlikely)

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AETIOLOGY & PATHOGENESIS

Causes of Lumen Obstruction (most important factor):

⭐ Faecolith - so important it provides indication for prophylactic appendicectomy

Other Factors:

• Diet - low fibre, high meat/fish diet (Western diet)
• Social status - "disease of aristocratic families" (Classes I & II)
• Familial susceptibility

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PATHOLOGY - Sequence of Events (Obstructive Type)

Obstruction
    ↓
Closed loop → Luminal distension (capacity only 0.1 mL!)
    ↓
0.5 mL secretion distal → Intraluminal pressure ↑ to 50 cmH₂O
    ↓
Visceral nerve stimulation → VAGUE, DIFFUSE pain (umbilical/epigastric) T10
    ↓
Vascular congestion → Engorgement → Bacteria invade submucosa
    ↓
Fever, tachycardia, leucocytosis
    ↓
Serosa involved → Pain SHIFTS TO RIGHT LOWER QUADRANT (RLQ)
    ↓
Perforation (most commonly at tip/antimesenteric border near faecolith)
    ↓
Peritonitis / Appendicular mass / Abscess

⭐ Empyema of appendix = distension with pus ⭐ Mucocele of appendix = distension with mucus

Bacteriology:

• Mixed aerobic + anaerobic colonic flora
• E. coli, Bacteroides (gram -ve rod), non-haemolytic streptococci, Cl. Welchii

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3. CLINICAL FEATURES ⭐⭐

SYMPTOMS - Murphy's Triad

⭐ Sequence: Pain → Anorexia → Nausea/Vomiting (if reversed, question diagnosis!)

PHYSICAL SIGNS

SIGNS ON PALPATION ⭐

⭐ Diagnosis of appendicitis is ESSENTIALLY CLINICAL

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4. ALVARADO SCORE ⭐⭐

⭐ Score ≥7 = Acute appendicitis → immediate operation ⭐ Score 5-6 = Borderline → further investigation Mnemonic: MANTRELS (Migration, Anorexia, Nausea, Tenderness RIF, Rebound, Elevated temp, Leucocytosis, Shift left)

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5. SPECIAL INVESTIGATIONS

⭐ Chest X-ray: exclude basal pneumonia (simulates appendicitis) ⭐ Barium enema: UNNECESSARY in most cases

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6. MODIFIED FEATURES BY POSITION ⭐

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7. COMPLICATIONS OF ACUTE APPENDICITIS ⭐⭐

1. Appendicular Rupture

• Using antibiotics to postpone surgery = DANGEROUS, NEVER ADVISED
• Rupture usually distal to obstruction (or at obstruction site)
• → General peritonitis

2. Appendicular Mass (Phlegmon) ⭐

• Develops on 3rd day of acute appendicitis attack
• Omentum + coils of small bowel wrap around inflamed appendix
• No discrete pus inside
• Usually resolves conservatively
• If untreated → may form abscess

3. Appendicular Abscess ⭐

• Progressive suppuration in appendicular mass
• Commonest site: Lateral part of iliac fossa (retrocaecal appendicitis)
• 2nd common site: Pelvis
• Features: Pyrexia + ↑ WBC + ↑ polymorphonuclear cells
• Untreated → peritonitis from secondary rupture

4. Suppurative Pylephlebitis

• Ascending septic thrombophlebitis of portal venous system
• Grave but rare complication of gangrenous appendicitis
• → Multiple pyogenic liver abscesses
• Signs: Chills, spiking fever, RUQ pain, jaundice

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8. APPENDICITIS IN SPECIAL GROUPS ⭐⭐

Infants & Children

• History inaccurate → diagnosis difficult → delayed → complications
• Perforation rate: 50-80% (greater omentum immature, can't wall off)
• Diarrhoea common → often admitted to medical ward
• ⭐ "Beware of diarrhoea in a child with abdominal pain" - exclude appendicitis first

Young Women (20-30 years)

• Commonly misdiagnosed as: Mittelschmerz, salpingitis, ectopic gestation, ovarian pathology
• Barium enema helps exclude appendicitis if symptoms don't progress

Pregnancy ⭐

• Most common extrauterine abdominal emergency in pregnancy
• More common in 1st and 2nd trimesters
• Symptoms similar to non-pregnant in first 6 months
• 3rd trimester: Mortality ~20% (10x more than 1st/2nd trimester)
  • Pain higher + more lateral (uterus displaces appendix)
  • ↑ Perforation risk → premature delivery possible
• Treatment: Appendicectomy at ALL stages of pregnancy
• ⭐ "Early appendicectomy is treatment of choice"

Elderly

• Symptoms mild/vague → late diagnosis
• Rigidity NOT prominent (lax abdominal wall)
• May be misdiagnosed as intestinal obstruction
• Early perforation due to impaired blood supply
• ⭐ "Elderly die because surgeons don't operate in doubtful cases"

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9. DIFFERENTIAL DIAGNOSIS ⭐

A. Abdominal Causes

• Acute cholecystitis, Perforated peptic ulcer
• Cyclical vomiting (children - acetone in urine, no rigidity)
• Mesenteric lymphadenitis (<10 yrs, post-URTI, diffuse tenderness, lymphocytosis, no rigidity)
• Intestinal obstruction, Crohn's disease, Amoebic colitis
• Meckel's diverticulitis, Acute pancreatitis

B. Gynaecological

• Salpingitis, Ectopic gestation
• Mittelschmerz (ruptured follicle - mid-cycle, no fever/leucocytosis)
• Twisted ovarian cyst

C. Retroperitoneal

• Right ureteric colic, Right pyelonephritis, Torsion of testis

D. Thoracic

• Basal pneumonia, Pleurisy

E. Others

• Henoch-Schonlein purpura, Porphyria, Diabetic abdomen

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10. TREATMENT ⭐⭐

Immediate appendicectomy = treatment of choice

⭐ NEVER use antibiotics alone to postpone surgery - makes appendix gangrenous and causes rupture

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🔑 HIGH-YIELD EXAM POINTS SUMMARY

1. Most common acute surgical condition of abdomen = Acute appendicitis
2. Most common cause of obstruction = Faecolith
3. Pain sequence: Periumbilical → RLQ (visceral → somatic)
4. Murphy's triad: Pain → Anorexia → Vomiting (in this order!)
5. Alvarado score ≥7 = operate; 5-6 = investigate further
6. Best investigation = USG (specificity >90%)
7. Appendicular mass develops on 3rd day; treat conservatively
8. Highest mortality in pregnancy = 3rd trimester (~20%)
9. Rupture rate in children = 50-80% (immature omentum)
10. Psoas sign = Retrocaecal appendix; Obturator sign = Pelvic appendix
11. Pylephlebitis = rare but grave = portal vein septic thrombosis
12. Diagnosis is ESSENTIALLY CLINICAL

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