The Effect of General Anesthesia on Microcirculation as Assessed Using Noninvasive Near-Infrared Spectroscopy During...

To evaluate the effects of opioid-based general anesthesia induction on microcirculatory function using near-infrared spectroscopy (NIRS)-derived tissue oxygen saturation (StO₂) combined with vascular occlusion testing (VOT) in pediatric patients undergoing congenital cardiac surgery.

Prospective observational before-and-after study.

Single-center tertiary pediatric cardiac surgery unit.

A total of 135 pediatric patients scheduled for elective congenital cardiac surgery were screened; 120 patients completed paired measurements and were included in the final analysis.

Microcirculatory parameters were assessed using NIRS-based VOT before anesthesia induction and 30 minutes after induction, prior to surgical incision.

Baseline StO₂ significantly increased after anesthesia induction (78.8% ± 12.4% v 85.1% ± 9.96%, p = 0.04). Minimum StO₂ was higher, and the occlusion slope was reduced, indicating decreased tissue oxygen consumption (p = 0.001). Reperfusion time was significantly prolonged (22.4 ± 10.2 seconds v 28.7 ± 20.1 seconds, p = 0.001), and reperfusion slope was decreased (1.82%/s ± 1.16%/s v 1.27%/s ± 0.98%/s, p = 0.001), suggesting impaired microvascular reactivity.

Induction of general anesthesia is associated with significant alterations in microcirculatory dynamics in pediatric cardiac surgery patients. These changes occur despite relatively preserved macrocirculatory stability, indicating a dissociation between macrocirculation and microcirculation. NIRS combined with VOT may provide valuable noninvasive insight into perioperative microcirculatory function; however, the clinical significance of these findings requires further investigation.