Neuraxial anesthesia is less harmful to the endothelial glycocalyx during elective joint surgery compared to general anesthesia

BACKGROUND: Damage of the endothelial glycocalyx (EG) has been described during surgery, but the effect of different anesthesia techniques remains unknown. Perfused boundary region (PBR) evaluated by side-stream dark field (SDF) imaging of the sublingual microcirculation enables in vivo EG assessment. PBR values are inversely related to the EG thickness. OBJECTIVE: The aim of the observational study was to evaluate the changes of PBR in patients undergoing elective joint surgery under general (GA) vs. neuraxial anesthesia (NA). Our hypothesis was that PBR will be lower in patients in NA. METHODS: Sixty consecutive patients (ASA 1-3) undergoing elective total knee or hip replacement under GA or NA were included in this prospective observational cohort study. PBR in the sublingual microcirculation was recorded in each patient using SDF at two time points - before surgery and 2 hours after surgery. RESULTS: Before surgery, there was no significant difference in baseline PBR between groups (NA: 1.95 μm (±0.24); GA: 2.02 μm (±0.26); p = 0.098). Postoperatively (2 hours after surgery) PBR was significantly increased in both groups with respect to baseline values (NA: 2.09 μm (±0.19), GA: 2.20 μm (±0.25); p < 0.001). In the GA group, postoperative PBR values were significantly higher than in the NA group (p = 0.006). CONCLUSION: Joint surgery led to significant increases of PBR. Patients in the GA group had significantly higher PBR values 2 hours after surgery compared to NA group. This might implicate that NA is associated with less EG damage then GA in elective hip/knee surgery.