Assessment and comparison of microcirculation and macrocirculation in horses undergoing emergency exploratory celiotomy versus elective surgical procedures.
Authors: Foth Patrick W, Gardner Alison, Pereira Carolina Ricco, Cooper Edward, Schroeder Eric, Mudge Margaret C
Journal: Veterinary surgery : VS
Summary
# Editorial Summary Researchers used hand-held videomicroscopy to examine the oral buccal microcirculation of horses undergoing emergency colic surgery, comparing their microvascular parameters with those of healthy horses having routine elective procedures, and assessing whether these microscopic findings correlated with standard circulatory measures like cardiac output and blood pressure. Nine colic cases were imaged at three intervals (30, 90, and 150 minutes post-induction), whilst 11 elective cases were imaged once at 45 minutes; analysis quantified vessel density, perfusion status, and microvascular heterogeneity, with concurrent measurement of mean arterial pressure, cardiac output, and lactate levels. Surprisingly, no meaningful differences emerged between the colic and elective groups across any microcirculatory parameters, nor did measurements change over time within the colic group, and microvascular indices showed only weak negative correlation with cardiac output. This finding suggests that side stream dark-field microscopy may lack sufficient sensitivity to detect clinically relevant microcirculatory changes during equine colic surgery, though the authors acknowledge that sample size limitations, probe location variability, and heterogeneity in disease severity may have masked genuine physiological differences. For practitioners, whilst microcirculation assessment holds theoretical promise for monitoring anaesthetised horses, this work indicates that traditional macrocirculatory parameters—blood pressure, cardiac output, and lactate—remain more reliable indicators of tissue perfusion status during emergency abdominal surgery.
Read the full abstract on PubMed
Practical Takeaways
- •Bedside microcirculation assessment using hand-held videomicroscopy may not reliably indicate systemic perfusion status in colic horses and should not be used in isolation for hemodynamic monitoring
- •Traditional macrocirculatory parameters (MAP, cardiac output, lactate) should remain the primary indicators for assessing tissue perfusion in emergency equine surgery
- •Further research with larger sample sizes and varied probe locations may be needed before recommending dark-field microscopy as a clinical monitoring tool in equine colic surgery
Key Findings
- •No significant differences in buccal mucosal microcirculatory parameters (vessel density, perfusion, heterogeneity) between emergency colic horses (n=9) and elective surgical horses (n=11) under general anesthesia
- •Microcirculatory parameters remained stable across three timepoints (30, 90, 150 min) in colic horses during surgery
- •Weak negative correlation (rho = -0.23) between microvascular parameters and cardiac output, indicating poor agreement between micro- and macrocirculatory measures
- •Dark-field microscopy of buccal mucosa may lack sensitivity to detect clinically relevant microcirculatory changes in colic compared to healthy horses