Albumin Enhances Microvascular Reactivity in Sepsis: Insights from Near-Infrared Spectroscopy and Vascular Occlusion...

Area of Science:

• Critical Care Medicine
• Biomedical Engineering
• Hemodynamics

Background:

• Microcirculatory dysfunction is a key factor in septic shock, leading to organ failure and mortality.
• Sidestream dark-field (SDF) imaging is the gold standard for microvascular perfusion assessment but is complex for routine use.
• Near-infrared spectroscopy with vascular occlusion testing (NIRS-VOT) is explored as a simpler bedside tool for monitoring microcirculation.

Purpose of the Study:

• To evaluate NIRS-VOT for assessing microcirculatory changes post-fluid resuscitation in septic shock patients.
• To compare NIRS-derived reoxygenation slope (ReOx) with clinical severity scores and SDF imaging parameters.
• To determine the potential clinical utility of NIRS-VOT in critical care settings.

Main Methods:

• Sixty-three fluid-responsive sepsis patients were randomized to receive albumin or crystalloid.
• NIRS-VOT and sublingual SDF measurements were taken at baseline and 60 minutes post-resuscitation.
• The NIRS reoxygenation slope (ReOx) was calculated and correlated with clinical data and SDF parameters.

Main Results:

• ReOx significantly increased post-resuscitation in the albumin group (p=0.025), but not in the crystalloid group.
• ReOx at 60 min showed inverse correlations with APACHE II score (ρ=-0.325) and lactate (ρ=-0.277).
• NIRS ReOx demonstrated weak correlations with SDF parameters like number of crossings (p=0.03) and CPPV (p=0.004).

Conclusions:

• NIRS-VOT detected microcirculatory trends following albumin administration in sepsis.
• NIRS-VOT showed limited agreement with SDF imaging, suggesting they measure different physiological aspects.
• Further research is needed to establish the clinical role of NIRS-VOT for microcirculation monitoring.