Appendicitis is inflammation of the vermiform appendix, a small blind-ended tube attached to the cecum. It is the most common cause of emergency abdominal surgery and occurs most often between the ages of 10 and 30, although it can occur at any age.

Sequence

1. The lumen becomes obstructed — by a fecalith (appendicolith), lymphoid hyperplasia (after viral infection), or, less often, a tumor or parasites
2. Mucus accumulates, pressure rises, and bacteria multiply
3. Rising pressure compresses veins, then arteries → ischemia, gangrene
4. Perforation (often within about 24–72 hours of symptom onset) → localized abscess or generalized peritonitis and sepsis

Why pain moves: early distension of the appendix stimulates visceral nerves, felt vaguely around the umbilicus. When inflammation reaches the parietal peritoneum, pain becomes sharp and localizes to the right lower quadrant (RLQ).

Higher-risk groups for delayed diagnosis and perforation

• Older adults — fewer symptoms, less fever, lower WBC response
• Young children — cannot describe symptoms; children under 5 have high perforation rates
• Pregnant clients — the enlarging uterus pushes the appendix upward and laterally, so pain may be in the right mid-abdomen, right upper quadrant, or flank
• Immunosuppressed clients

Typical sequence

• Periumbilical pain → migrates to the RLQ over several hours
• Anorexia (very common), then nausea and vomiting — usually after pain begins
• Low-grade fever; higher fever suggests perforation

Physical examination

• Tenderness at McBurney point (one-third of the way from the anterior superior iliac spine to the umbilicus) — the most important examination finding
• Rebound tenderness and guarding (peritoneal irritation)
• Rovsing sign: pressing the left lower quadrant causes RLQ pain
• Psoas sign: RLQ pain with extension of the right hip (retrocecal appendix)
• Obturator sign: RLQ pain with internal rotation of the flexed right hip (pelvic appendix)
• Pain with coughing, walking, or bumps on the ride to hospital

Signs of perforation

• Sudden relief of pain followed by increasing, diffuse pain
• High fever, tachycardia, hypotension, rigid abdomen, distension, absent bowel sounds

Pain assessment — location and migration, character, intensity, onset, aggravating and relieving factors; reassess often, because a change in pattern is diagnostic information.

Conditions that mimic appendicitis

Appendectomy — standard treatment

• Laparoscopic appendectomy is preferred for most clients: less pain, shorter stay, faster recovery, fewer wound infections
• Open appendectomy for some complicated cases
• Perforated appendicitis: appendectomy, peritoneal lavage, possible drains, and IV antibiotics continued for a short, defined course after source control
• A well-formed abscess may be drained percutaneously first, with antibiotics

Antibiotics

• Preoperative IV antibiotics covering gram-negative and anaerobic bacteria (e.g., ceftriaxone plus metronidazole, or piperacillin–tazobactam)
  • Metronidazole: nausea, metallic taste; avoid alcohol during and for 3 days after
  • Ceftriaxone: allergy; cross-reactivity with penicillin is low, but avoid if the penicillin reaction was a severe delayed reaction (e.g., Stevens–Johnson syndrome or toxic epidermal necrolysis); must not be given simultaneously with IV calcium solutions in neonates
  • Piperacillin–tazobactam: penicillin allergy; C. difficile risk

Antibiotics-first (nonoperative) option

• For selected adults with uncomplicated appendicitis confirmed on CT, antibiotics alone are a reasonable alternative. In a large US trial (CODA, 2020), antibiotics were noninferior to surgery for health status at 30 days, but about 3 in 10 clients needed appendectomy within 90 days, and the risk was higher when an appendicolith was present
• Shared decision-making is required; clients need clear instructions about recurrence

Pain relief — give analgesia (including opioids) to clients with suspected appendicitis. Current evidence shows appropriate analgesia does not mask the diagnosis or delay surgery; withholding it is outdated practice.

Preoperative (priority order)

1. Monitor for perforation and sepsis — vital signs, temperature, pain changes, abdominal rigidity; report sudden pain relief followed by worsening pain, high fever, tachycardia, or hypotension
2. Maintain NPO and prepare for surgery (consent, IV access, labs)
3. IV fluids for hydration; hourly urine output and emesis amount in intake and output — vomiting and NPO cause fluid deficit; urine output reflects renal perfusion
4. Give analgesics and antibiotics as ordered
5. Position of comfort — semi-Fowler's or side-lying with knees flexed
6. Do not apply heat to the abdomen and do not give laxatives or enemas — they may increase the risk of perforation

Postoperative

1. Airway and breathing — deep breathing, coughing (splinting the incision), and incentive spirometry with good pain control to prevent atelectasis and pneumonia
2. Early ambulation — prevents VTE, ileus, and pulmonary complications; relieves laparoscopic shoulder pain from CO₂
3. Pain — multimodal analgesia (acetaminophen, NSAIDs if not contraindicated, opioids as needed)
4. Return of bowel function — bowel sounds, flatus; advance diet as tolerated; watch for ileus or obstruction (vomiting, distension, reduced or absent bowel sounds)
5. Wound and drains — dressings, drainage amount and character; perforated cases have higher wound infection and abscess risk
6. Fluid balance — intake and output until drinking well
7. Antibiotics — uncomplicated appendicitis needs no antibiotics after appendectomy; perforated cases continue IV antibiotics for the ordered course

• Before diagnosis: do not take laxatives, enemas, or apply heat for unexplained abdominal pain; seek care for pain that moves to the right lower abdomen, fever, or vomiting
• After laparoscopic surgery: most return to normal activities within about 1–3 weeks; avoid heavy lifting and strenuous exercise for the period the surgeon advises
• Shoulder pain after laparoscopy is from gas and resolves in a day or two; walking helps
• Keep incisions clean and dry; showering is usually permitted; report redness, swelling, warmth, drainage, or fever
• Drains are removed by the health care provider — never pull out a drain yourself; if sent home with a drain, empty and record output as taught
• Report increasing abdominal pain, vomiting, inability to pass gas, or fever (abscess, ileus)
• Finish any prescribed antibiotics
• Antibiotics-first treatment: know that symptoms can recur; return promptly with new pain

• Classic: periumbilical pain → RLQ, anorexia, nausea after pain, low-grade fever
• Key exam finding: McBurney point tenderness with rebound; Rovsing, psoas, obturator signs
• Labs: leukocytosis with neutrophilia; always a pregnancy test in anyone who could be pregnant
• Imaging: CT in adults; ultrasound in children and pregnancy
• Pregnancy: pain may be higher — right upper quadrant or flank
• Preoperative: NPO, IV fluids, antibiotics, analgesia is appropriate; no heat, no laxatives, no enemas
• Sudden pain relief then worse diffuse pain = perforation; hypotension and tachycardia = septic shock
• I&O: urine output and vomitus are key
• Postoperative: deep breathing, coughing with splinting, incentive spirometry, early ambulation
• Ileus/obstruction signs: vomiting, distension, absent bowel sounds
• Drains are removed only by the provider
• Antibiotics-first is an option for uncomplicated cases, but recurrence and later surgery are common