Intra-abdominal abscess (IAA) is an intra-abdominal collection of pus or infected material, usually due to a localised infection inside the peritoneal cavity. It can involve any intra-abdominal organ or be located in between bowel loops, or be free within the peritoneal cavity itself.
Commonly presents with abdominal pain, fever, and leukocytosis.
Usually secondary to inoculation, commonly from complicated intra-abdominal infection (i.e., bowel perforation, anastomotic leak, trauma).
Diagnosis can be confirmed by radiological studies such as ultrasound or computed tomography (CT) scan. CT scan of the abdomen and pelvis is often more reliable, and provides better delineation of anatomical location and size of the IAA.
Treatment involves adequate source control (abscess drainage, whether percutaneous or surgical) as well as early appropriate and effective antimicrobial therapy.
If untreated, may lead to clinical deterioration including sepsis or septic shock.
Intra-abdominal abscess (IAA), also known as intraperitoneal abscess, is an intra-abdominal collection of pus or infected material and is usually due to a localised infection inside the peritoneal cavity. It can involve any intra-abdominal organ or can be located freely within the abdominal or pelvic cavities, including in between bowel loops. IAA is almost always secondary to a pre-existing disease process, or concomitant intra-abdominal process. It can be caused by one or multiple bacterial, fungal, or parasitic infectious agents.
History and exam
Key diagnostic factors
- presence of risk factors
- fever or hypothermia
- abdominal pain
- rectal tenderness and fullness
Other diagnostic factors
- change in bowel habits/abnormal bowel function
- prolonged ileus
- anorexia/lack of appetite
- nausea and vomiting
- palpable mass
- signs of sepsis
- pre-operative corticosteroid use
- recent surgery or trauma, appendicitis, diverticulitis, or perforated ulcer
1st investigations to order
- WBC count
- drainage culture
- abdominal CT scan
Investigations to consider
- serum CRP
- serum erythrocyte sedimentation rate (ESR)
- Gram stain of abscess fluid
- serum glucose
- abdominal ultrasound
- abdominal MRI scan
- endoscopic ultrasound
community-acquired intra-abdominal abscess: non-high risk, mild-to-moderate severity
community-acquired intra-abdominal abscess: high risk or high severity
health care-associated intra-abdominal abscess
- Loculated intra-abdominal haematoma
- Pancreatic pseudocyst
- Diverticular or appendiceal phlegmon
- ACR appropriateness criteria: radiologic management of infected fluid collections
- The management of intra-abdominal infections from a global perspective: 2017 WSES guidelines for management of intra-abdominal infections
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