Evaluation of aqueous tear production in dogs after general anaesthesia with medetomidine‐propofol‐carprofen‐halothane

Abstract

The influence of an anaesthetic protocol, which included medetomidine, propofol, carprofen and halothane on tear production in the dog. There are no previous studies on the effects of this combination on tear production in dogs or in any other species. The present study included 39 dogs, which underwent non-ophthalmic surgery in our clinic. Preanaesthetically, all dogs had normal tear production (18.62±3.65 mm/minute) as this was recorded with Schirmer tear test I (STT I) and the ophthalmologic examination did not reveal anything abnormal. Tear production readings were recorded before the administration of premedication, at the end of anaesthesia, one hour and two hours postanaesthesia. No reverse agent was administrated. At the end of anaesthesia (right eye (oculus dexter, OD) P<0.0005, left eye (oculus sinister, OS) P<0.0005), as well as one hour postanaesthesia (OD P=0.020, OS P=0.001) there was a statistically significant reduction in tear production, which returned to normal values two hours postanaesthesia, regardless of the duration of the operation. This anaesthetic combination resulted in a decrease in tear production and, therefore, the use of tear substitute treatment in dogs undergoing anaesthesia with this protocol (combination) from the time the sedative is given until at least two hours after the end of anaesthesia is highly recommended.

Dexmedetomidine and Tear Production: Evaluation in Dogs as Spontaneous Model for Ocular Surface Disorders

“…The main cause is the suppression of parasympathetic innervation of the lacrimal gland, as demonstrated in rats and rabbits experimentally para-sympathectomized by sectioning of the greater superficial petrosal nerve [9][10][11]. A marked decrease in tear production after induction of anesthesia has been reported in humans [12][13][14][15] and in dogs, using different anesthetic and sedative protocols [16][17][18][19][20][21]. The loss of corneal integrity resulting from perioperative dry eye can lead to corneal abrasions, which are the most common ocular complication in humans during general anesthesia for non-ophthalmic surgery [20,22].…”

“…The loss of corneal integrity resulting from perioperative dry eye can lead to corneal abrasions, which are the most common ocular complication in humans during general anesthesia for non-ophthalmic surgery [20,22]. Post-anesthesia corneal lesions have been reported also in dogs [17,20,21], cats [23,24] and horses [25].…”

Schirmer Tear Test Value and Corneal Lesions’ Incidence during General Anesthesia for Non-Ophthalmic Surgery in Non-Brachycephalic Dogs: A Pilot Study Comparing Three Different Lubricant Eye Drop Formulations

“…Adverse ocular side effects of GA are lagophthalmos, leading to exposure keratopathy (EK); loss of eyelid reflex; decreased basal tear production and reduced stability of the corneal tear film [2]. Anesthesia induced corneal lesions have been reported also in dogs [3][4][5][6][7][8], cats [9,10] and horses [11].…”

Postanästhesiologische Tränenproduktion und Irritationen am Auge der Katze

“…Sedation. Beim Hund wurde in drei Arbeiten auch der postanästhetische Zeitraum untersucht (15,18,20). In diesen Studien konnte eine signifikant verminderte TPM bis zu 24 Stunden nach Narkoseende nach gewiesen werden.…”