What are the signs of a chemoport infection?

Signs of Chemoport Infection

Chemoport infections present with distinct clinical patterns: local signs at the insertion site (erythema, tenderness, pain, induration, purulent drainage) or systemic signs (fever, chills, hypotension, sudden-onset sepsis after port use), with the presentation pattern often indicating the causative pathogen. 1

Classification of Chemoport Infections

Chemoport infections can be categorized into three distinct types 1:

• Localized infections at the catheter entrance: Inflammation within ≤2 cm of the insertion site 1
• Port-pocket infections: Clinical signs of infection and inflammation in the subcutaneous pocket of the implanted port system 1
• Catheter-related bloodstream infections (CRBSI): Systemic infection with positive blood cultures and no other identifiable source 1

Local Signs and Symptoms

At the insertion site or port pocket, look for 1:

• Erythema (redness around the port site)
• Tenderness and pain at or around the port
• Induration (hardening of tissue)
• Purulent drainage or exudate from the insertion site
• Warmth over the port area 2
• Swelling at the catheter site 1

Systemic Signs and Symptoms

Systemic manifestations indicating bloodstream infection include 1:

• Fever (most common systemic sign)
• Chills occurring with or without hypotension
• Hypotension suggesting sepsis
• Signs of sepsis of sudden onset, particularly after catheter use or port flush 1
• Catheter dysfunction (inability to flush or draw blood) 1

Clinical Presentation Patterns Linked to Pathogens

The presentation pattern can suggest the causative organism 2:

Port Flush Form Infection

• Onset of fever and chills with or without hypotension immediately following port flush 2
• Typically caused by nosocomial glucose non-fermenting gram-negative bacilli (91% of cases), particularly Acinetobacter baumannii (50%) and Enterobacter cloacae (18%) 2
• Occurs at a mean of 272 days after port implantation 2

Local Inflammatory Form Infection

• Presence of local inflammatory signs (erythema, warmth, tenderness, pus formation) plus systemic infection signs 2
• Predominantly caused by gram-positive cocci (86% of cases), especially Staphylococcus aureus (71%) 2
• Occurs earlier, at a mean of 82 days after port implantation 2

Critical Clinical Context

The mortality rate for CRBSI in cancer patients is 12%–25%, making prompt recognition essential 1. Port-related infections occur in approximately 3%–16% of catheterizations, with an incidence of 0.66 per 1000 catheter days reported in pediatric oncology populations 1, 3.

Common Pitfalls to Avoid

• Do not delay obtaining blood cultures before initiating antimicrobial therapy when infection is suspected 4, 5
• Do not assume absence of local signs excludes infection—systemic CRBSI can occur without visible insertion site inflammation 1
• Do not overlook catheter dysfunction as a potential sign of infection, as thrombosis and infection often coexist 1
• Do not delay catheter removal when S. aureus, Pseudomonas, or Candida species are identified, as these require mandatory port removal 4, 5

Diagnostic Approach When Infection is Suspected

When clinical signs suggest chemoport infection 1, 4:

• Obtain paired blood cultures from the catheter and a peripheral vein before starting antibiotics 1, 4
• If peripheral access is unavailable, draw two blood samples from different catheter lumens at different times 1
• Culture any exudate at the exit site with gram staining 1
• Prepare skin with alcohol, iodine tincture, or alcoholic chlorhexidine (>0.5%) and allow adequate drying time 1, 5
• A differential time to positivity ≥2 hours between catheter and peripheral cultures is highly sensitive and specific for CRBSI 4, 5