Visceral and peripheral tissue perfusion after cardiac surgery

Area of Science:

• Cardiovascular Surgery
• Physiology
• Intensive Care Medicine

Background:

• Post-coronary artery bypass grafting (CABG) patients experience altered tissue perfusion and oxygenation.
• Monitoring visceral and peripheral circulation is crucial for early detection of complications.

Purpose of the Study:

• To investigate visceral and peripheral tissue perfusion and oxygenation in the early phase after CABG.
• To assess the dynamic changes in gastric intramucosal pH and peripheral circulation parameters.

Main Methods:

• Studied 10 patients in the early phase post-CABG.
• Assessed visceral perfusion via gastric intramucosal pH.
• Measured peripheral perfusion using subcutaneous PO2 (PscO2), transcutaneous PO2 (PtcO2), PtcO2 index, laser-Doppler skin red-cell flux (RCF), and fingertip temperature (Tft).
• Monitored central hemodynamics, rectal temperature, and blood gases with inspired oxygen at 30%.

Main Results:

• Gastric intramucosal pH progressively declined in the first 3 hours, reaching a minimum at 5 hours post-ICU admission.
• Peripheral vascular bed showed signs of shutdown upon ICU admission (low PscO2, PtcO2, PtcO2 index, RCF, Tft).
• Peripheral perfusion parameters improved significantly 2-4 hours after admission, indicating vasodilation by the end of the 8-hour study.

Conclusions:

• Visceral perfusion, indicated by gastric intramucosal pH, decreases initially after CABG.
• Peripheral tissue perfusion and oxygenation recover and normalize within 8 hours post-CABG.
• These findings highlight the dynamic changes in circulatory function following CABG surgery.