Laryngotracheal lesions following routine orotracheal intubation in the horse.

This study investigates the consequences of routine orotracheal intubation (a procedure where a tube is inserted into the trachea through the mouth) on healthy horses. Results reveal that all horses developed laryngeal and/or tracheal lesions following the procedure, highlighting a significant concern about the procedure’s safety.

Research Methodology

• The study involved 38 healthy horses that were brought to three different veterinary teaching hospitals. The inclusion of a relatively large sample size and the use of multiple sites might have increased the validity of the findings.
• In order to control for possible variations, the researchers used either 30 mm id cuffed silicone endotracheal tubes or Cole cuffless tubes for all the horses during intubation.
• Endoscopic examination, a procedure allowing for the visual inspection of internal body structures, was used to assess the upper respiratory and tracheal areas. Examinations were carried out before the intubation, immediately after extubation (removal of the tube), and 24 hours post-extubation.
• From all the horses, four were selected and euthanized for deeper investigation. Their tissues were studied histologically (microscopically) to give a more detailed understanding of the lesions’ nature and extent.

Key Findings

• The main finding of this study is that all the horses developed some form of laryngeal (voice box) and/or tracheal (windpipe) lesions following the intubation procedure.
• These lesions manifested in several ways. There was a significant presence of mucus in the trachea, epithelial ecchymoses (a kind of skin discoloration due to bleeding), basement membrane hemorrhage, and plaques of diphtheritic membranes (tissue remnants from inflammation) covered in mucus.
• Given that these horses were healthy prior to the procedure, it can be deduced that the observed conditions were a direct consequence of intubation.
• The histological examination of the four necropsied horses further confirmed that the damage was comparable to what has been reported in other species that underwent similar tracheal intubation procedures.

Implications

• This research raises concerns about routine orotracheal intubation in horses, as it appears to consistently cause laryngeal and/or tracheal lesions.
• Therefore, alternatives to this procedure or ways to minimize its adverse effects might need to be explored to ensure the safety and wellbeing of horses undergoing such procedures.