Intra-abdominal Abscess
last authored: Feb 2010, David LaPierre
last reviewed:
Introduction
Intra-abdominal abscess can be a serious complication of gastrointestinal conditions or surgery. Their formation is often indolent, making diagnosis at times difficult, but most patients are febrile.
Abscess may form from an intraabdominal organ following spread from blood, lymph, or gut. They may also develop as extravisceral abscess in the peritoneal or retroperitoneal spaces, usually following peritonitis or lumenal rupture.
The Case of...
Causes and Risk Factors
Liver abscess
Liver abscess usually occurs among patients with other conditions, including
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Causative organisms can include:
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Splenic abscess
Splenic abscesses generally result from hematogenous spread:
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Causative organisms can include:
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Pancreatic abscess
Pancreatitis can uncommonly result in pancreatic abscess, leading to persistent or recurrent fever. |
Causative organisms can include:
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Extravisceral abscess
Extravisceral abscess can follow:
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Causative organisms can include:
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Pathophysiology
Abscesses represent local collections of pus walled off by inflammation, omentum, or viscera.
Extraperitoneal abscess can occur in the subphrenic, pelvic, or retroperitoneal space.
Intermittent bacteremia can result in recurrent fevers and rigors.
Liver seeding can occur through the hepatic portal veins. Abscesses can be single or multiple.
Signs and Symptoms
- history
- physical exam
History
Presenting symptoms are diverse and include:
- abdominal pain, often poorly localized
- nausea, vomiting
- paralytic ileus
Subphrenic abscesses can cause:
- shoulder pain (referred diaphragmatic pain, C3,4)
- hiccup
- pulmonary manefestations
Splenic abscess can cause:
- left upper quadrant abdominal pain, potentially pleuritic
Pelvic abscesses can cause:
- polyuria
- diarrhea
- tenesmus
History of abdominal surgery
Physical Exam
Physical exam can reveal
- focal tenderness
- ileus
Pyogenic hepatic abscess can cause
- right-sided pain
- hepatomegaly
- jaundice in less than 25% of patients
Splenic abscess can cause:
- pleural rub or effusion
Investigations
- lab investigations
- diagnostic imaging
Lab Investigations
elevated WBC is often present
Needle aspiration can be used to perform gram stain and culture and assist with therapy.
Liver abscess can lead to
- elevation of alkaline phosphatase
- modest elevation of bilirubin
Entamoeba histolytica titres can assess for a possible cause of liver abscess
Diagnostic Imaging
Abdominal X-ray can reveal:
- extravisceral gas
- air-fluid levels
Chest X-ray can show:
- elevated right diaphragm, atalectasis, or effusion with liver abscess
Abdominal ultrasound can reveal fluid collection, especially in the pelvis.
CT, and MRI can be very helpful.
Differential Diagnosis
Liver tumour...
Treatments
Drainage
Percutaneous drainage is the first line treatment, guided by CT. Surgical intervention is indicated if drainage fails.
Antibiotics
IV antibiotics should be given at the same time, emperically and then according to culture results.
Antibiotics are rarely sufficient, save with amebic abscess or multiple microabscesses of the liver.
Confounding issues include
- decreased tissue penetration (septations
- inactivation by bacterial enzymes
- low pH
- low redox potential: hypoxic environment - poor for aminoglycosides
broad-spectrum antibiotics
- piperacillin-tazobactam
- cephotaxime-metronidazole (not Pseudomonas, not enterococcus)
- ampicillin-gentamycin-metronidazole
- metronidazole for E. histolytica
- amphotericin B or fluconazole for Candida
Surgery
Biliary tract obstruction should be relieved surgically if present.
Splenectomy is usually the treatment for splenic abscess.
Consequences and Course
Resources and References
Open-Access
Non-Open-Access
Marshall JC, Innes M. 2003. Intensive care unit management of intra-abdominal infection. Crit Care Med. 31(8):2228-37.
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