Risk of circuit infection in septic patients on extracorporeal membrane oxygenation: a preliminary study

Area of Science:

• Critical Care Medicine
• Infectious Diseases
• Biomaterials Science

Background:

• Extracorporeal membrane oxygenation (ECMO) is vital for severe lung failure in sepsis.
• Microbiological colonization of membrane oxygenator (MO) surfaces is a concern in bacteremic patients.
• Long-term ECMO necessitates understanding risks associated with artificial surfaces.

Purpose of the Study:

• To investigate the risk of MO infection in septic patients undergoing long-term ECMO.
• To determine if MO colonization can lead to unexplained clinical deterioration.
• To evaluate MO exchange as a potential intervention for such cases.

Main Methods:

• Studied 10 consecutive septic patients on long-term ECMO.
• Analyzed flushing fluids of investigated MOs for sterility.
• Incubated one MO with nutrient solution for 14 days to assess for microbial growth.
• Monitored clinical parameters including D dimers and fibrinogen levels.

Main Results:

• Flushing fluids from all MOs were sterile.
• Enterococci spp. were isolated from one MO after 14-day incubation.
• The patient with the colonized MO developed unexplained bleeding, which resolved after MO exchange.
• Clinical markers like D dimers and fibrinogen changed prior to MO exchange, but standard infection markers were unremarkable.

Conclusions:

• Circuit infection of the MO is a potential cause of unexplained clinical deterioration in ECMO patients.
• Consider MO exchange when faced with unexplained clinical decline in ECMO patients.
• This highlights the importance of monitoring for subclinical circuit infections during ECMO therapy.