Should Air Bubble Detectors Be Used to Quantify Microbubble Activity during Cardiopulmonary Bypass?

Area of Science:

• Cardiovascular Surgery
• Biomedical Engineering
• Medical Device Technology

Background:

• Air bubble detectors (ABDs) are critical for preventing air embolism during cardiopulmonary bypass (CPB).
• Stockert ABDs quantify microbubbles larger than 300 μm, but their clinical reliability remains unverified.
• Accurate microbubble detection is essential for patient safety during CPB procedures.

Purpose of the Study:

• To evaluate the reliability of Stockert SIII and S5 air bubble detectors.
• To compare the microbubble quantification performance of ABDs against the EDAC system during CPB.

Main Methods:

• Conducted 12 CPB procedures, simultaneously measuring microbubble counts using two ABDs and two EDAC quantifiers in series.
• Assessed reliability using Spearman correlation coefficients between ABD and EDAC measurements for microbubbles >300 μm.
• Analyzed correlations between SIII ABDs and EDAC, and between S5 ABDs and EDAC.

Main Results:

• No significant correlation was found between SIII ABDs and EDAC (r = .008, p = .793).
• A weak negative correlation was observed for S5 ABDs (r = -.16, p < .001).
• EDAC detectors showed strong correlation (SIII: r = .958, p < .001; S5: r = .908, p < .001); SIII ABDs showed small-medium correlation with EDAC (r = .286 to .347).
• No correlation was found between the second SIII ABD and EDAC detectors (r = .003).
• Correlation analysis between EDAC and S5 ABD was hindered by low detected bubble counts >300 μm.

Conclusions:

• Both Stockert SIII and S5 ABDs demonstrate unreliability in quantifying microbubble activity during CPB when compared to the EDAC system.
• The findings underscore the need for accurate and clinically relevant data in CPB reports.
• Microbubble counts from devices like the SIII and S5 ABDs should not be reported due to their demonstrated inaccuracy.