Changes in intraocular pressure during cardiopulmonary bypass

Area of Science:

• Cardiology
• Ophthalmology
• Surgical Technology

Background:

• Cardiopulmonary bypass (CPB) is a critical procedure in cardiac surgery.
• Maintaining physiological parameters, including intraocular pressure (IOP), is essential during CPB.
• Understanding the impact of different CPB modes on IOP is crucial for patient safety.

Purpose of the Study:

• To investigate the changes in intraocular pressure (IOP) during pulsatile versus non-pulsatile cardiopulmonary bypass (CPB).
• To compare IOP fluctuations in patients undergoing coronary artery bypass grafting (CABG) with different CPB modalities.

Main Methods:

• 42 patients undergoing elective CABG were randomized into pulsatile (Group P) and non-pulsatile (Group N) CPB groups.
• IOP measurements were taken at multiple time points: pre-anesthesia, pre-CPB, during CPB (5-60 min), post-CPB, and end-of-operation.
• Statistical analysis compared IOP changes within and between the two groups.

Main Results:

• A statistically significant decrease in IOP was observed from baseline, persisting throughout most of the CPB duration, except for a transient increase at 5 minutes.
• Pre-CPB and 5-minute CPB measurements showed significantly higher IOP in the pulsatile CPB group compared to the non-pulsatile group.
• Despite initial differences, repeated IOP measurements did not reveal significant long-term variations between the pulsatile and non-pulsatile CPB groups.

Conclusions:

• IOP generally decreases during CPB, with a notable transient increase at 5 minutes.
• Pulsatile CPB may be associated with higher initial IOP compared to non-pulsatile CPB, though this difference diminishes with continued CPB.
• The study highlights the dynamic nature of IOP during CPB and suggests further investigation into the clinical implications of these findings.