A systematic review of the effects of injectable sedative and anesthetic drugs and inhalant anesthetics on intraocular pressure in the dog.

OBJECTIVE: The purpose of this systematic review was to summarize the results of studies that have determined the effect of injectable and inhalant drugs used in anesthesia on intraocular pressure (IOP) in dogs. DATABASES USED: A comprehensive search of research literature was performed without language restriction. The search utilized the PubMed, CAB Abstracts and the University of Georgia's Galileo electronic databases using a combination of free text terms 'Ophthalmology', 'Intraocular Pressure', 'Anesthetic', 'Anesthesia', 'Canine' or 'Dog'. The time frame searched was from 1970 to October 2018. Any published research paper that dealt with sedatives or anesthetics administered systemically and the canine eye was evaluated. CONCLUSIONS: The effects of many anesthetic drugs in dogs with ocular pathology are largely unknown. Many anesthetic drugs do not induce clinically relevant changes in IOP in dogs with normal eyes, although some studies demonstrated results with statistically significant changes. The dose, route of administration, experimental conditions, drug combinations, timing of measurements, measurement technology and setting or individual animal characteristics may all produce some heterogeneity in results from multiple studies.

Transorbital endotracheal intubation: a nonstandard approach to a difficult airway.

We present the case report of a 49-year-old gentleman with a history of adenoid cystic carcinoma of the left nare status post curative bifrontal craniotomy, left lateral rhinotomy and medial maxillectomy, adjuvant radiotherapy, and orbital exenteration for optic neuropathy, complicated by medial wall dehiscence. His course was also complicated by severe radiation trismus, for which he was scheduled to undergo bilateral mandibular coronoidectomies. Given his limited mouth opening, the surgeon requested a nasal endotracheal tube. Because of concerns of traumatizing his nare, we utilized a flexible fiberoptic bronchoscope to perform asleep transorbital intubation. Airway management in patients with severe trismus may require ingenuity.

Effect of duration and type of anesthetic on tear production in dogs.

OBJECTIVE: To determine effects of duration and type of anesthetic on tear production in dogs. ANIMALS: 8 female Beagles. PROCEDURES: Each dog was randomly allocated into 1 of 4 groups according to a Latin square design to receive anesthesia as follows: 1 hour with isoflurane, 1 hour with desflurane, 4 hours with isoflurane, and 4 hours with desflurane. Each dog was anesthetized with the selected inhalant 4 times during a 4-week period, with at least 5 days separating anesthetic episodes. Aqueous tear production was measured via the Schirmer I tear test at baseline and 10 minutes, 30 minutes, and 1 hour after induction of anesthesia as well as 2, 3, and 4 hours after induction for the 4-hour groups. Tear production was also measured after the dogs were standing after recovery from anesthesia and 2, 10, and 22 hours after recovery from anesthesia. RESULTS: Aqueous tear production was significantly reduced in dogs during anesthesia and returned to baseline values immediately after recovery and until 10 hours after anesthesia in all treatment groups. Inhalant type and duration had no significant effect. Neither lateral recumbency nor left versus right eyes had a significant effect. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that inhalant anesthetics did not reduce tear production after anesthesia and that longer-duration anesthesia did not cause decreased tear production, compared with shorter-duration anesthesia.