Acute appendicitis — risk scores and imaging

Working diagnosis. Classic migrating pain to RIF with anorexia, low-grade fever and localised RIF peritonism — high pretest for acute appendicitis. β-hCG negative excludes pregnancy-related differentials but still consider ovarian pathology.^[1]

Scores. Reproduce Alvarado (MANTRELS): Migration, Anorexia, Nausea/vomiting, Tenderness RLQ (2), Rebound, Elevated temperature, Leukocytosis (2), Shift of left — double points for RLQ tenderness and leukocytosis, one point for each other component. Intermediate–high scores support imaging/surgical review rather than discharge.^[1] AIR score — vomiting, RIF pain, graded rebound, temperature 38.5 or above, graded WCC, graded polymorphs, graded CRP — bands low 0–3, intermediate 4–8, high 9–12 (validation: complicated unlikely below 4 with NPV 99%; likely above 8 with PPV 96 in the young).^[3]

Imaging. In a young woman, ultrasound first (radiation-sparing; also evaluates adnexa). CT if USS equivocal/non-diagnostic. Do not delay surgical review if peritonitis evolves.^[6]

Management.

• NBM, IV fluids, morphine titrated, ondansetron IV for nausea.
• Early surgical referral for laparoscopic appendicectomy (most effective: lower wound infection and morbidity, shorter stay).^[7]
• Antibiotics once diagnosis made/highly likely: ceftriaxone 2 g 24-hourly + metronidazole 500 mg 6-hourly (WSES-advised empiric cover).^[7]
• Antibiotics-only pathway (APPAC/CODA) is a shared-decision option for imaging-confirmed uncomplicated disease with substantial recurrence risk — not default in fit young adults.^[5]

Safety. Serial examination; low-risk scores make complicated appendicitis unlikely (NPV 99), but never discharge on bloods alone if clinical concern remains.^[3]