Plasma-free hemoglobin levels in advanced vs. conventional infant and pediatric extracorporeal life support circuits
Amanda M Cornelius1, Jeffrey B Riley, Gregory J Schears
1Division of Cardiovascular Surgery, Mayo Clinic, Rochester, Minnesota 55905, USA. cornelius.amanda@mayo.edu
Insights
The new extracorporeal membrane oxygenation (ECMO) II circuit, featuring a magnetic levitation pump, did not significantly alter plasma-free hemoglobin (PFH) levels compared to the ECMO I circuit. However, ECMO II showed fewer mechanical issues and clot buildup in pediatric patients.
Area of Science:
- Pediatric Cardiology
- Cardiopulmonary Support
- Biomedical Engineering
Background:
- Extracorporeal life support (ECLS) is crucial for pediatric cardiorespiratory failure.
- Previous extracorporeal membrane oxygenation (ECMO) circuits (ECMO I) used roller pumps and polypropylene oxygenators.
- A new ECMO circuit (ECMO II) was adopted in 2010, featuring a magnetically levitated pump and polymethylpentene oxygenator.
Purpose of the Study:
- To compare plasma-free hemoglobin (PFH) levels between ECMO I and ECMO II circuits in pediatric patients.
- To evaluate the impact of ECMO circuit technology on hemolysis and circuit complications.
Main Methods:
- Retrospective chart review of pediatric patients (≤3 years, <13 kg) requiring ECLS.
- Comparison of daily PFH values between 18 ECMO II patients and 18 matched ECMO I patients.
- Analysis of factors including time on ECMO, age, weight, and mechanical complications.
Main Results:
- No significant difference in mean PFH levels between ECMO I and ECMO II circuits.
- PFH levels significantly increased with hours on ECMO in both groups.
- The ECMO I circuit showed a significantly greater increase in PFH with ECMO hours.
- ECMO II circuit was associated with significantly fewer mechanical component change-outs and less clot buildup.
Conclusions:
- The ECMO II circuit technology did not significantly alter average PFH levels compared to ECMO I.
- Advancements in ECMO II circuit components led to improved mechanical reliability and reduced circuit complications.
- Further research may explore long-term outcomes and specific benefits of ECMO II components.
Abstract:
Extracorporeal life support (ECLS) is a reliable method to support pediatric patients with reversible cardiorespiratory failure associated with congenital heart disease, respiratory insufficiency, or after cardiac surgery. In 2010, our institution adopted an infant/pediatric extracorporeal membrane oxygenation (ECMO) circuit that contains a magnetically levitated centrifugal pump, polymethylpentene oxygenator, and shorter tubing length (ECMO II circuit). Our prior circuit contained a nonocclusive roller pump, polypropylene oxygenator, venous compliance chamber, and hemoconcentrator (ECMO I circuit). A retrospective chart review comparing ECMO I and ECMO II daily plasma-free hemoglobin (PFH) values was conducted. We hypothesized that the PFH is similar between the two ECMO circuit groups. We reviewed medical records of children 3 years of age or younger weighing less than 13 kg who required ECLS between January 2008 and February 2012. PFH levels from 18 ECMO II patients were compared with levels in a retrospective group of an equal number of well-matched ECMO I circuit patients. There was no significant difference between ECMO I and ECMO II circuit groups regarding mean time on ECMO, age in days, and weight. There was also no significant difference in the group mean levels of PFH between ECMO I and ECMO II circuits. There was a significant increase in PFH with hours on ECMO (p < .01) within and between both circuit groups (p < .01) and a significantly greater increase in PFH with ECMO hours (p = .0091) in the ECMO I circuit group. Although there was no significant difference in average PFH with the change in ECMO II circuit technology, advancements such as the magnetically levitated blood pump and polymethylpentene gas exchange device has been associated with significantly fewer mechanical component change-outs (p = .0156) and less clots and fibrin build-up in the circuits (p = .0548).
