Pleuropulmonary and cardiovascular consequences of thoracoscopy performed in healthy standing horses.
Authors: Peroni J F, Robinson N E, Stick J A, Derksen F J
Journal: Equine veterinary journal
Summary
# Editorial Summary Peroni and colleagues investigated the cardiopulmonary safety of standing thoracoscopy by performing 18 procedures (six right thoracoscopies, six left thoracoscopies, and six sham procedures) on six healthy horses sedated with detomidine, measuring cardiovascular and respiratory variables at multiple time points during and after the procedure. Detomidine administration itself reduced heart rate, respiratory rate and cardiac output while increasing systemic and pulmonary vascular resistances; thoracoscopy further increased these vascular resistances, particularly during the second pneumothorax period, and caused a measurable decline in arterial oxygen tension that was more pronounced during left-sided procedures. Despite these physiological changes, no clinical complications emerged in the 48-hour postoperative period, though two horses developed subclinical pneumothorax (one associated with iatrogenic lung laceration). For practitioners considering standing thoracoscopy in healthy horses, these findings provide reassurance that the procedure does not produce lasting cardiopulmonary derangement, though the oxygen desaturation noted—especially with left-sided approaches—warrants monitoring and careful patient selection, particularly in horses with pre-existing respiratory or cardiac compromise.
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Practical Takeaways
- •Exploratory thoracoscopy is a relatively safe procedure in healthy horses with minimal postoperative complications, though careful trocar placement is needed to avoid iatrogenic lung laceration
- •Left-sided thoracoscopy may produce greater oxygen desaturation than right-sided procedures; monitor oxygenation closely and be prepared to manage hypoxemia during longer procedures
- •Detomidine sedation significantly reduces cardiac output and oxygenation independent of thoracoscopy; consider these effects when selecting sedation protocols and monitoring surgical candidates
Key Findings
- •Heart rate, respiratory rate, and cardiac output decreased following detomidine administration but thoracoscopy itself caused further increases in systemic and pulmonary vascular resistances
- •Arterial oxygen tension (PaO2) decreased following detomidine and was further reduced during second pneumothorax, with lower values during left versus right thoracoscopy
- •Only subclinical postoperative complications occurred in 2 of 6 horses (one with lung laceration), with no significant clinical complications within 48 hours post-procedure
- •Thoracoscopy in healthy, awake, pharmacologically restrained horses did not cause detrimental cardiopulmonary effects or postoperative complications in the first 48 hours