The term acute abdomen refers to the rapid onset of severe symptoms of abdominal pathology. Acute abdomen may indicate a potentially life-threatening condition that requires urgent surgical intervention. Acute abdominal pain is a common reason for emergency department attendance.
Immediate assessment should focus on distinguishing patients with true acute abdomen that requires urgent surgical intervention from patients who can initially be managed conservatively. Data from the UK suggest that access to an experienced surgeon reduces unnecessary admissions.
A patient with acute surgical pathology may deteriorate rapidly; patients with severe, unremitting symptoms warrant thorough investigation and close monitoring.
be located in any quadrant of the abdomen
be intermittent, sharp or dull, achy, or piercing
radiate from a focal site
be accompanied by nausea and vomiting.
Acute abdomen can occur without pain in older people, children, and the immunocompromised, and in the last trimester of pregnancy.
An acute abdomen is diagnosed by a combination of history, physical examination, imaging, and laboratory results.
One meta-analysis of randomised controlled trials that included adult patients with acute abdominal pain found that opioid analgesia does not increase the risk of diagnosis error or treatment decision error, and improves patient comfort. [ ]
Abdominal pain in older people, the immunocompromised, and pregnant women often presents atypically, which can lead to delayed diagnosis of life-threatening abdominal pathology.
Comorbid conditions or medications used to treat them may affect an older patient's ability to mount a characteristic physiological response.
Older patients are at higher risk for more severe disease due to decreased immune function.
Central and peripheral nervous systems are affected by ageing. Conditions such as dementia can restrict an older person's ability to communicate problems, and decreased peripheral nervous system function can alter perception of pain and temperature, making diagnosis and management more difficult.
One study of patients with perforated ulcers found that only 21% of older patients presented with peritonitis.
The physical and physiological changes associated with pregnancy may present a challenge to diagnosis and treatment.
The enlargement of the uterus, which displaces and compresses intra-abdominal organs, and the laxity of the abdominal wall makes it difficult to localise pain and can blunt peritoneal signs.
Pregnant women may have a mild physiological leukocytosis, so this finding is non-specific in pregnant women presenting with an acute abdomen.
If there is a high index of suspicion for intra-abdominal pathology, further studies are warranted and may include additional laboratory testing, radiographic testing, or in some cases serial physical examinations.
Immunocompromised patients mount an altered inflammatory response, and may display atypical symptoms and signs of acute abdominal pathology. Abdominal pain is usually non-specific, and physical examination is often inconclusive.
Immunocompromised patients are susceptible to opportunistic infections, e.g., cytomegalovirus colitis in patients with AIDS.
An acute abdomen may occur as a result of immunosuppressive therapy. Typhlitis (neutropenic enterocolitis) is a complication of chemotherapy that typically presents with fever, neutropenia, and right iliac fossa pain 10 to 14 days after initiation of chemotherapy.
A lower threshold for admission to hospital and cross-sectional imaging is required in immunocompromised patients.
- Incarcerated/strangulated hernia
- Perforated gastric ulcer
- Ectopic pregnancy
- Pelvic inflammatory disease
- Acute pancreatitis
- Acute diverticulitis
- Ulcerative colitis
- Crohn's disease
- Gastrointestinal malignancy
- Mallory-Weiss tear
- Diabetic ketoacidosis
- Opioid withdrawal
- Infectious colitis
- Sickle cell crisis
- Testicular torsion
- Kidney stones
- Perforated duodenal ulcer
- Ruptured ovarian cyst
- Ovarian torsion
- Abdominal aortic dissection
- Ruptured aortic aneurysm
- Acute mesenteric ischaemia (AMI) and infarction
- Myocardial infarction
- Meckel's diverticulitis
- Hepatic abscess
- Psoas abscess
- Oesophageal perforation (Boerhaave’s syndrome)
- Fitz-Hugh Curtis syndrome
- Ischaemic colitis
- Ruptured splenic artery aneurysm
- Budd-Chiari syndrome
- Splenic infarct
- Abdominal wall haematoma
- Addisonian crisis
- Acute intermittent porphyria (AIP)
- Hereditary Mediterranean fever
- Typhlitis (neutropenic enterocolitis)
- Radiation enteritis
- Heavy metal poisoning
- Spider bite
- Diagnosis and management of acute left-sided colonic diverticulitis: a clinical guideline from the American College of Physicians
- ACR appropriateness criteria: right lower quadrant pain
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