ABSCESSES AND FISTULAS
ABSCESSES AND FISTULAS
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| Abscess |
Risk Factors:
¤ Recent abdominal surgery
¤ Penetrating or blunt abdominal trauma
¤ Perforation of appendix or colonic diverticulum
¤ Perforation associated with intra-abdominal malignancy
¤ Crohn disease
¤ Chronic diseases, cirrhosis, renal failure
¤ Drugs: corticosteroids & chemotherapy
¤ Prior radiotherapy.
History
¤ High spiking fevers with chills
¤ Abdominal pain
¤ Nausea & vomiting
¤ Hiccups
¤ Chest pain
¤ Dyspnea
¤ Shoulder pain.
What are the symptoms of the abscess ?
Signs & Symptoms
¤ Tachycardia
¤ Abdominal tenderness
¤ Ileus
¤ Pleural effusion
¤ Basilar rales.
Tests
Basic Blood Tests
¤ Leukocytosis with left shift
¤ Anemia
¤ Non-specific elevation of bilirubin & liver enzymes.
Specific Diagnostic Tests
¤ Positive blood cultures
¤ Positive cultures from aspiration of abscess
¤ Most common aerobes: E coli & Enterococcus
¤ Most common anaerobes: Bacteroides.
Imaging
¤ Plain abdominal & chest films: air-fluid levels in area of abscess , elevation of right diaphragm in subphrenic abscess.
¤ Gallium scan: useful for smaller abscess not well seen on imaging.
¤ CT: imaging modality of choice for identification of abscess; also allows aspiration for culture.
¤ US: less sensitive for abdominal abscesses.
¤ Charcoal or methylene blue: oral administration with detection in drainage from fistula.
Differential diagnosis
¤ Necrotic tumors.
What is the treatment for an abscess ?
Management
What to Do First
¤ Complete diagnostic studies, particularly imaging, for localization & aspiration.
General Measures
¤ Initiate general supportive care: fluid & electrolyte replacement, establish feeding (TPN if fistula present) oxygenation if needed.
¤ Swan-Ganz catheter, mechanical ventilation &/or vasopressors if unstable.
Specific therapy
¤ Adequate drainage of abscess either percutaneously or by surgery
¤ Surgery indicated if pt. fails to respond to percutaneous drainage in 1–2 days.
¤ Establish adequate drainage of enterocutaneous fistulas, eg, open recent surgical excision, use of percutaneous catheters
¤ Surgery for complex fistulas or failure to resolve w/ external drainage & TPN
¤ Antibiotics: broad spectrum initially, & then based on culture results.
Follow-up
¤ Frequent clinical evaluation early after drainage
¤ Serial imaging when treated with catheter drainage to confirm catheter without abscess & abscess closed.
Complications and Prognosis
Complications
¤ Multi-organ failure leading to death
¤ Recurrent abscess
¤ Fistula formation
¤ Bowel obstruction
¤ Pneumonia
¤ Pleural effusion.
Is an abscess a serious infection ?
Prognosis
¤ Good with adequate drainage & response to antibiotic therapy.
