A comparison of the effects of propofol and thiopental on tear production in dogs

Abstract

RESUMO Comparação da produção lacrimal em cães após indução anestésica com Propofol e TiopentalO filme lacrimal tem função importante na manutenção da integridade da superfície ocular. Durante a anestesia geral sua produção é diminuída consideravelmente, o que exige cuidados para prevenir efeitos adversos que resultam em doenças destas estruturas. Ainda não foram realizadas pesquisas comparando-se os efeitos da indução com o tiopental e com o propofol na produção lacrimal. Como estas drogas são utilizadas na Medicina Veterinária, resolveu-se avaliar a produção lacrimal de 30 cães submetidos à procedimentos cirúrgicos experimentais e de rotina no Hospital Veteriná-rio da The tear film plays an important role in maintaining the integrity of the ocular suface. During general anesthesia, tear production is considerably reduced, which requires care to prevent adverse effects that result in diseases of these structures. Studies comparing the effects of induction of anaesthesia with thiopental and propofol on tear production have not been carried out yet. Because these drugs are used in veterinary medicine, we decided to evaluate the tear production in 30 dogs undergoing experimental surgery as well as routine procedures at the veterinary hospital of Federal University of Viçosa. Patients were divided into two groups of equal number. All animals were sedated with clorpromazine and maintained with isoflurane in diluted oxygen. Group 1 was induced with thiopental whereas group 2 with propofol. Schirmer tear test 1 was performed before sedation (T0), 15 minutes after sedation (T1) and 10 minutes after induction of anesthesia (T2) with the drug chosen for one of the groups. There was a significant decrease in tear production for both drugs, but no significant statistical differences were found between them. Thus, considering the results and the way in which the study was conducted, we suggest protecting the cornea and conjunctiva of patients during anesthesia using any of the drugs here evaluated.

Comparison of pupil diameter and tear production in dogs treated with acepromazine, tramadol and their combination

“…Differences found between the left and right eyes can be attributed to increased exposure of the ocular surface of the eye right to pachymetry, with subsequent drying, Pontes et al (2010) also observed differences in tear production between the eyes due to the greater exposure of the ocular surface of one of them.…”

“…During this time, the eyelids of the eye examined remained closed. Then, the same procedure was performed on the left eye (STT-LE), using a new sterile strip (Slatter, 2005c;Pontes et al, 2010).…”

“…However, most of anesthetics induce miosis (Bechara, 2002;Slatter, 2005a;Gross & Giuliano, 2007) and reduction of tear production, thus requiring corneal lubrication during these anesthesia procedures (Krupin et al, 1977;Brightman et al 1983;Herring et al 2000;Pontes et al 2010).…”

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 ].…”

Keratoconjunctivitis sicca exacerbation in a dog treated with systemic atenolol

“…, Pontes et al . ), and the decrease in tear production can be transient or irreversible. In human medicine, β‐blockers are recognised as reducing tear production when used either locally or systemically (Petounis & Akritopoulos ).…”