Intra-abdominal abscess

Last reviewed: June 2019

Last updated: March 2018

Summary

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.

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 tomographic (CT) scan. CT scan of the abdomen and pelvis is usually more reliable, and provides better delineation of anatomical location and size of intra-abdominal abscess.

Treatment involves adequate source control (abscess drainage) and early appropriate effective antimicrobial therapy.

If untreated, may cause sepsis and septic shock.

Definition

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 or other disease process. [1] 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
hx of inflammatory bowel disease
rectal tenderness and fullness

Full details

Other diagnostic factors

tachycardia
change in bowel habits/abnormal bowel function
prolonged ileus
anorexia/lack of appetite
nausea and vomiting
hx of biliary disease
palpable mass
malnourishment
signs of sepsis

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Risk factors

diabetes
malignancy
recent surgery or trauma, appendicitis, diverticulitis, or perforated ulcer
male sex
age >65 years

Full details

Diagnostic investigations

1st investigations to order

WBC count
abdominal CT scan

Full details

Investigations to consider

serum CRP
serum ESR
Gram stain of abscess fluid
drainage culture
serum glucose
serum LFTs
serum albumin
abdominal ultrasound
abdominal MRI scan
indium-labelled leukocytes

Full details

Emerging tests

fluorodeoxyglucose (FDG)-positron emission tomography (PET) and FDG-PET/CT
endoscopic ultrasound

Full details

Treatment algorithm

ACUTE

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

Contributors

Authors VIEW ALL 

Laura Kreiner, MD, FACS

Assistant Professor of Surgery

MetroHealth Medical Center

Case Western Reserve University School of Medicine

Cleveland

Disclosures

LK declares that she has no competing interests.

Acknowledgements

Dr Laura Kreiner would like to gratefully acknowledge Dr Ali F. Mallat, Dr Lena M. Napolitano, and Dr Lillian Kao, previous contributors to this monograph. AFM declares that he has no competing interests. LMN has been a member of the speakers' bureau and consultant for Merck, Pfizer, Schering-Plough, Ortho-McNeil, Wyeth, and Astellas Pharma. LK declares that she has no competing interests.

Peer reviewers VIEW ALL 

James T. Lee, MD, PhD, FACS, FIDSA, FSHEA

Professor of Surgery (retired)

University of Minnesota

Saint Paul

Disclosures

JTL declares that he has no competing interests.

Jeffrey A. Claridge, MD, MS, FACS

Director of Research

Division of Trauma, Burns and Critical Care

Assistant Professor

Department of Surgery

MetroHealth Medical Center

Case Western Reserve University School of Medicine

Cleveland

Disclosures

JAC declares that he has no competing interests.

Matthew Falagas, MD, MSc, DSc

Director

Alfa Institute of Biomedical Sciences

Marousi

Athens

Greece

Disclosures

MF declares that he has no competing interests.

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Intra-abdominal abscess

Summary

Definition

History and exam

Key diagnostic factors

Other diagnostic factors

Risk factors

Diagnostic investigations

1st investigations to order

Investigations to consider

Emerging tests

Treatment algorithm

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

Contributors

Authors VIEW ALL 

Laura Kreiner, MD, FACS

Disclosures

Acknowledgements

Peer reviewers VIEW ALL 

James T. Lee, MD, PhD, FACS, FIDSA, FSHEA

Disclosures

Jeffrey A. Claridge, MD, MS, FACS

Disclosures

Matthew Falagas, MD, MSc, DSc

Disclosures

Differentials

Guidelines

Patient leaflets

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