What are the guidelines for insertion and drainage procedure for an abscess or fluid collection?

Guidelines for Insertion and Drainage Procedure for Abscesses and Fluid Collections

Surgical incision and drainage is the primary recommended treatment for most abscesses, with timing based on the severity of sepsis and patient condition. 1

Diagnostic Approach Before Drainage

• Imaging is crucial for proper evaluation of abscesses, with CT scanning being the first-line imaging modality for identifying and characterizing collections, especially for abdominal collections 1, 2
• Ultrasound should be used to guide thoracocentesis or drain placement, as it can reveal the exact location of the fluid collection and is superior for identifying septations with 81-88% sensitivity and 83-96% specificity 2, 1
• MRI may be useful for better tissue characterization in certain anatomical locations 1
• For suspected anorectal abscesses, imaging investigations are suggested in cases of atypical presentation and suspicion of occult supralevator abscesses, complex anal fistula, or perianal Crohn's disease 2

Pre-Procedure Preparation

• Routine measurement of platelet count and clotting studies are only recommended in patients with known risk factors 2
• Where possible, any coagulopathy or platelet defect should be corrected before drain insertion 2
• Informed consent must be obtained by the doctor performing the procedure or an appropriately trained individual with sufficient knowledge to explain the nature and risks 2
• For anorectal abscesses, check serum glucose, hemoglobin A1c, and urine ketones to identify undetected diabetes mellitus 2
• In patients with signs of systemic infection or sepsis, complete blood count, serum creatinine, and inflammatory markers (e.g., C-reactive protein, procalcitonin, and lactates) should be checked 2

Procedural Considerations

• Chest drains should be inserted by adequately trained personnel with a suitable assistant and trained nurse available to reduce the risk of complications 2
• For children, general anesthesia is usually preferred over intravenous sedation, especially for non-cooperative children with respiratory compromise 2
• Local anesthetic should still be used in an anesthetized patient for pain control 2
• Two basic techniques are available for percutaneous catheter drainage (PCD): the Seldinger technique and the trocar technique 2
• For inadequate drainage of thick collections, consider upsizing the drainage catheter to a larger bore 1

Specific Approaches Based on Collection Type

Anorectal Abscesses

• Surgical approach with incision and drainage is strongly recommended 2
• Timing of surgery should be based on the presence and severity of sepsis 2
• In fit, immunocompetent patients with small perianal abscesses without systemic signs of sepsis, outpatient management can be considered 2
• No recommendation can be made regarding the use of packing after drainage of an anorectal abscess 2

Loculated Collections

• For loculated collections that are difficult to drain completely, consider catheter upsizing for inadequate drainage 1
• Intracavitary thrombolytic therapy may be used to break up septations 1
• Multiple drainage catheters may be necessary for complex loculations 1

Thick Viscous Abscesses

• Thick, viscous abscess contents are a known predictor of percutaneous drainage failure 1
• For inadequate drainage of thick collections, consider upsizing the drainage catheter to a larger bore 1
• Larger abscesses (>5 cm) or those with thick, viscous contents that cannot be adequately drained percutaneously may be best managed surgically 1

Antibiotic Therapy

• In patients with drained anorectal abscess, antibiotic administration is suggested in the presence of sepsis and/or surrounding soft tissue infection or in case of immune response disturbances 2
• Sampling of drained pus is recommended in high-risk patients and/or in the presence of risk factors for multidrug-resistant organism infection 2
• All drainage procedures should be accompanied by appropriate antibiotic therapy 1

Common Pitfalls and Considerations

• Inadequate drainage of loculations is associated with high recurrence rates and treatment failure 1
• Ultrasound guidance during drainage can help identify and break up septations that might otherwise be missed 1
• Immunocompromised patients may require more aggressive and earlier drainage 1
• For loculated collections associated with fistulas or enteric communications, longer-term drainage may be necessary 1
• Underestimating the viscosity of abscess contents can lead to selection of inappropriate drainage methods 1