The Effect of General Anesthesia on Microcirculation as Assessed Using Noninvasive Near-Infrared Spectroscopy During Vascular Occlusion Testing in Pediatric Cardiac Surgery.

OBJECTIVES

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.

DESIGN

Prospective observational before-and-after study.

SETTING

Single-center tertiary pediatric cardiac surgery unit.

PARTICIPANTS

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.

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

MEASUREMENTS AND MAIN

RESULTS

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.

CONCLUSIONS

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.