Dr Ignacio Sàndez, responsible for anesthesia at Sinergia Veterinaria, which is a veterinary clinic in Madrid, performed an elbow surgery on a dog.

He used 0,2 microgram/kilogram of methadone and 2,0 microgram/kilogram of dexmedetomidine were administered on premedication.
When he started the surgery, he realized the PTA values were low (picture) so he added 0,4 microgram/kilogram of ketamine and the PTA went up and stabilized on the normal range values.

The PTA (Parasympathetic Tone Activity) technology enables the evaluation of the parasympathetic part of the autonomic nervous system of animals from the electrocardiogram retrieved by sensors (clips).

The PTA index provides an objective value to veterinarians to evaluate analgesia. The PTA Monitor offers a value between 0 and 100 corresponding to the activity of the parasympathetic part of the autonomic nervous system of the animal. The higher the value of the PTA index is, the higher the animal’s comfort is important.
In this case, the the PTA showed the right amount of dexmedetomidine that needed to be used in order to assess the comfort/pain of the dog.