Acute abdomen (obstruction / perforation / peritonitis)Refer

• Ringer lactate / Normal saline, Ceftriaxone + Metronidazole, Piperacillin-tazobactam (severe), Pantoprazole (perforated ulcer), Paracetamol IV

• Also: Nil by mouth, NG tube if vomiting or obstructed, catheter; erect chest X-ray or CT; surgeon now (WSES 2017, latest)

First visit

• Erect chest X-ray and X-ray abdomen — Free air under the diaphragm; dilated loops and fluid levels.
• CBC, creatinine, electrolytes, blood glucose — Baseline and dehydration.
• Blood group and crossmatch — Before surgery.
• Urine pregnancy test — Women of child-bearing age.

Only if indicated

• CT abdomen — Uncertain cause or level of obstruction.
• Lipase — Exclude pancreatitis.
• Serum lactate, blood culture — Sepsis or suspected bowel ischaemia.