Differential Diagnoses Based on Location of Pain
Right Upper Quadrant
- Biliary Colic
- Acute Cholecystitis
- Acute Cholangitis
Right Iliac Fossa
- Acute Appendicitis
- Ectopic Pregnancy
- Ovarian Cyst
- Meckel’s Diverticulitis
Epigastric
- Pancreatitis
- Peptic Ulcer Disease
- Abdominal Aortic Aneurysm
Central / Generalised
- Abdominal Aortic Aneurysm
- Intestinal Obstruction
- Ischaemic Colitis
Left Iliac Fossa
- Diverticulitis
- Ectopic Pregnancy
- Ovarian Cyst
Suprapubic
- Acute Urinary Retention
- Pelvic Inflammatory Disease
Loin to Groin
- Renal Colic (kidney stones)
- Abdominal Aortic Aneurysm
- Pyelonephritis
Peritonitis
- Inflammation of the peritoneum (the lining of the abdomen)
- Localised peritonitis is caused by underlying organ inflammation (e.g. appendicitis or cholecystitis)
- Generalised peritonitis is caused by perforation of an abdominal organ (e.g. perforated duodenal ulcer or ruptured appendix)
- Spontaneous bacterial peritonitis is associated with spontaneous infection of ascites in cirrhotic liver disease, is treated with antibiotics and carries a poor prognosis
Investigations for obtaining a diagnosis and preparing the patient for theatre
- FBC gives an indication of bleeding (drop in Hb) and infection / inflammation (raised WBC)
- U&E gives an indication of electrolyte imbalance and kidney function (useful prior to CT scans, as they require a contrast injection that can damage kidneys)
- LFTs give an indication of the state of the biliary and hepatic system
- CRP gives an indication of inflammation and infection
- Amylase gives an indication about inflammation of the pancreas in acute pancreatitis
- INR gives an indication of the synthetic function of the liver and is essential in establishing their coagulation prior to procedures
- PO2 (on an ABG) and blood calcium are required in scoring acute pancreatitis
- Group and Save is essential prior to theatre in case the patient requires a blood transfusion
- Blood lactate gives an indication of tissue ischaemia
- Abdominal xray can provide evidence of bowel obstruction by showing dilated bowel loops
- Erect chest xray can demonstrate air under the diaphragm when there are intraabdominal perforation
- Ultrasound abdomen can be useful in checking for gallstones, biliary duct dilatation and gynaecological pathology
- CT scans are often required to identifying the cause of an acute abdomen and determine correct management
Initial Management of an Acute Abdomen
- ABCDE approach to priorise resuscitation
- Nil by mouth
- IV access (the bigger the cannula the better)
- IV fluids
- IV antibiotics (if evidence of infective cause)
- Analgesia and antiemetics
- NG tube if vomiting and suspected obstruction
- Catheterise for fluid balance monitoring
- Obtain investigations as above
- Escalate to registrar / consultant / critical care as appropriate to severity of the patient’s condition