Ropivacaine-Based Regional Anesthesia Exerts Muscle-Protective Effects Despite Elevated Compartment Pressure In A Porcine Model Of Acute Compartment Syndrome

Background: Acute compartment syndrome (ACS) is a devastating sequela of orthopedic trauma characterized by elevated compartment pressure (CP) that precipitates tissue ischemia. The role of regional anesthesia (RA) in modulating these pathophysiological events remains controversial. This study investigated the impact of RA via ropivacaine 0.2% (RPVC) on CP, systemic hemodynamics, biochemical markers, and tissue integrity in a porcine model of ACS. Methods: Twenty male pigs underwent ACS induction in the tibialis anterior compartment by targeted inflation of an angioplasty catheter and were randomized to receive either RPVC or placebo via a regional catheter. Continuous CP and mean arterial pressure (MAP) were recorded. Plasma samples (p-) and interstitial fluid (c-) were collected at predefined time points (T1, T3, T6, T8, T10) to quantify creatine kinase (CK), lactate (Lac), lactate dehydrogenase (LDH), and glucose (Gluc). Histopathological evaluation was performed at the end of the experiment (T10). Results: At T10, CP was significantly elevated in the RPVC group [57.0 mmHg (49.0–59.0)] compared to placebo [41.5 mmHg (38.2–47.2); p=0.022], whereas MAP remained comparable (RPVC: 63.0 mmHg [58.0–65.0] vs. placebo: 59.0 mmHg [56.2–61.8]; p=0.13). Plasma biomarkers did not differ significantly (e.g., p-CK: RPVC 1940 U/l [868–3334] vs. placebo 1171 U/l [1020–1467]; p=0.24). In contrast, interstitial analysis demonstrated a marked reduction in tissue injury markers in the RPVC group, with c-LDH significantly lower [24475 U/l (19500–28213) vs. 113800 U/l (91000–116600); p=0.017] and c-Gluc substantially decreased [19.5 mg/dl (11.5–27.5) vs. 51.0 mg/dl (43.0–103.0); p=0.0043]. RPVC-treated tissue exhibited attenuated degeneration and reduced necrosis in a blinded histopathological scoring. Conclusions: Despite a higher CP, RPVC-based RA yielded an improved regional metabolic profile and mitigated tissue injury in ACS. These findings suggest a protective effect in the observed timeframe that merits further clinical exploration.