Combining CRRT circuits with ECMO prolongs circuit life despite exposure to higher circuit pressures

Australia: New research published in Blood Purification: Critical Care Nephrology shows that combining continuous renal replacement therapy (CRRT) circuits with extracorporeal membrane oxygenation (ECMO) can result in a longer circuit life, despite exposure to higher circuit pressures.

The use of CRRT is common during ECMO and has specific technical characteristics which affect the circuit life. The researchers of the study aimed to assess CRRT hemodynamics and circuit life during ECMO.

The study compared ECMO and non-ECMO-CRRT treatments in two adult intensive care units over a 3-year period. A potential predictor of circuit survival was identified in a subset of data and subsequently assessed in the remaining data using a Cox proportional hazard model.

The study revealed the following clinical findings:

1. When CRRT circuits were used in conjunction with ECMO, the median circuit life was longer (28.8 hours) than when used alone (20.2 hours).

2. Access, return, prefilter, and effluent pressures were higher during ECMO, and higher ECMO flows were associated with higher access and return pressures.

3. High access pressures were identified as a predictor of an accelerated circuit failure in CRRT circuits used during ECMO, possibly due to progressive membrane thrombosis.

4. First access pressures ≥190 mm Hg and patient weight were independently associated with circuit failure.

5. Access dysfunction was associated with a stepwise increase in trans-filter pressure, suggesting a potential mechanism of membrane injury.

These findings have implications for the management of ECMO-CRRT patients, as clinicians may need to closely monitor access pressures and adjust ECMO flows accordingly to avoid circuit failure. The study also highlights the potential for membrane injury during ECMO-CRRT, indicating a need for further research into strategies to minimize this risk.

The lead author of the study Dr. B. Sansom said that “The study provides valuable insights into the hemodynamics and circuit life of CRRT during ECMO and underscores the importance of careful monitoring and management of these patients.”

Reference:

Sansom, B., Riley, B., Udy, A., Sriram, S., Presneill, J., & Bellomo, R. (2023, April 19). Continuous Renal Replacement Therapy during Extracorporeal Membrane Oxygenation: Circuit Haemodynamics and Circuit Failure. Continuous Renal Replacement Therapy During Extracorporeal Membrane Oxygenation: Circuit Haemodynamics and Circuit Failure Blood Purification - Karger Publishers; 2023 doi: https://doi.org/10.1159/000529928