Microcirculatory perfusion during different perioperative hemodynamic strategies

Area of Science:

• Anesthesiology
• Critical Care Medicine
• Surgical Oncology

Background:

• Optimizing fluid management is crucial for patient outcomes during surgery.
• Microcirculatory dysfunction can lead to organ damage.
• Previous strategies focused on macrohemodynamics may not adequately address microcirculatory needs.

Purpose of the Study:

• To compare the efficacy of pulse pressure variation (PPV) and cardiac index (CI) guided hemodynamic optimization versus a mean arterial pressure (MAP) based strategy.
• To determine if improved systemic perfusion translates to better microcirculatory perfusion in patients undergoing elective abdominal surgery.

Main Methods:

• Randomized controlled trial comparing a PPV/CI guided group (target PPV <12%, CI >2.5 L/min/m(2), MAP >70 mmHg) with a MAP-guided group (target MAP >70 mmHg).
• Noninvasive measurements of PPV, CI, and MAP.
• Sublingual microcirculatory perfusion assessed via total vessel density (TVD), perfused vessel density (PVD), and proportion of perfused vessels at multiple time points post-anesthesia induction.

Main Results:

• The PPV/CI group received significantly more fluid (1927 ± 747 mL) than the MAP-guided group (1283 ± 582 mL; p = 0.01).
• No significant differences were observed in TVD (p = 0.92), PVD (p = 0.77), or the proportion of perfused vessels (p = 0.76) between the groups.
• Despite increased fluid administration, microcirculatory perfusion remained comparable.

Conclusions:

• Hemodynamic optimization based on PPV and CI does not improve microcirculatory perfusion compared to a MAP-guided protocol in abdominal surgery.
• Current advanced hemodynamic monitoring strategies may not directly enhance microcirculatory function in this patient population.