scholarly journals Limited usefulness of the observation of eye bulb rotation and neuro-ophthalmic responses for assessing the depth of equine anesthesia: an observational study comparing three protocols

2021 ◽  
Vol 77 (10) ◽  
pp. 6586-2021
Author(s):  
OLGA DREWNOWSKA ◽  
BERNARD TUREK ◽  
BARBARA LISOWSKA ◽  
CHARLES E. SHORT ◽  
MAKSYMILIAN BIELECKI

The observation of the neuro-ophthalmic responses is an established basic tool for monitoring the depth of anesthesia in horses. However, their usefulness during balanced anesthesia in the clinic is questionable. The aim of this study was to compare the usefulness of neuro-ophthalmic responses during 3 commonly used anesthetic protocols. An observational study was performed on 22 horses, 5 maintained only with isoflurane (ISO group), 12 maintained with isoflurane and a constant rate infusion of ketamine (ISO+KET group), and 5 maintained with isoflurane and a constant rate infusion of detomidine (ISO+DET group). The occurrence of all five responses was noted: spontaneous palpebral and provoked palpebral response, corneal response, nystagmus and eye bulb rotation. The most consistent with the literature and most useful for anesthetic depth assessment was the observation of spontaneous palpebral reflex in all of the groups (p = 0.788) and the most significant differences were visible for the observation of the provoked palpebral reflex (p = 0.015) for all groups. The reflexes in the group ISO+DET were less consistent with the literature than in other groups, making them least useful. The group ISO seemed to have the reflexes’ observations most consistent with the literature expectations. The corneal reflex was always present and nystagmus always absent which confirmed the observations from literature. The above results suggest that neuro-ophthalmic responses, especially eye bulb rotation and provoked palpebral reflexes, should not be the only indicators in assessing the depth of anesthesia during maintenance with ketamine or detomidine with concurrent isoflurane.

Author(s):  
Aswathy Gopinathan ◽  
Kiranjeet Singh ◽  
Sherin B. Sarangom ◽  
V. Ramya ◽  
P. Sangeetha ◽  
...  

Background: Horses mount a huge stress response to anesthesia when compared to other animals, hence are risky candidates for anesthesia. Inhalant anesthetic agents offer more control to anesthetic depth and facilitate rapid recovery, hence are considered to be safer than intravenous agents for surgical procedures requiring more than an hour, however, newer drug combinations are being explored to minimize the undesired consequences and dose rate of inhalant agents. The present study explored the safety of dexmedetomidine, ketamine and lidocaine constant rate infusion alone or as a combination along with Isoflurane for safer anesthesia in horses.Methods: The study was conducted on 28 horses divided into S, D, DK and DKL groups having 7 animals in each. Xylazine (1 mg/kg) and butorphanol (0.05mg/kg) were given intravenously for premedication. Ketamine (2 mg/kg) and midazolam (0.2 mg/kg) were used for induction and anesthesia was maintained with isoflurane. Normal saline (1000ml/hour), Dexmedetomidine (2µg/kg/hr), Dexmedetomidine and ketamine (2 µg/kg/hr and 2 mg/kg/hr) and Dexmedetomidine, ketamine and lidocaine (2 µg/kg/hr, 2 mg/kg/hr and 2 mg/kg/h) were given as CRI in groups S, D, DK and DKL, respectively. Thiopentone sodium (250mg bolus, 5%) was given as a fast intravenous bolus whenever required. Anesthetic efficacy was evaluated based on clinical, haemato-biochemical, hemodynamic, and endocrine variables.Result: A significant decline in mean arterial pressure was noticed in group DKL but changes in CVP and SpO2 in different groups were non-significant. Higher Blood glucose and low Insulin levels were seen in group DK during 45-60 min. Constant rate infusions of Dexmedetomidine, Ketamine and Lidocaine alone or in combination produced a significant sparing effect on Isoflurane and thiopentone while they improved peri-operative quality of anesthesia in horses.


2011 ◽  
Vol 47 (6) ◽  
pp. e103-e109 ◽  
Author(s):  
Tilemahos L. Anagnostou ◽  
George M. Kazakos ◽  
Ioannis Savvas ◽  
Lysimachos G. Papazoglou ◽  
Timoleon S. Rallis ◽  
...  

Remifentanil is a synthetic opioid with direct action on μ opioid receptors. It has an ultrashort duration of action, and its elimination is independent of hepatic or renal function. The anesthetic management of five dogs with nonuniform liver disease and requiring liver biopsy via celiotomy is described. Remifentanil and isoflurane were used for induction and maintenance of anesthesia. Intraoperative analgesia was provided by a constant rate infusion of remifentanil. Remifentanil, in combination with isoflurane, was safely and successfully used in five cases for the balanced anesthesia of dogs with hepatic diseases requiring liver biopsy via celiotomy.


1986 ◽  
Vol 111 (4) ◽  
pp. 516-521
Author(s):  
Nina Clausen ◽  
Per-Eric Lins ◽  
Ulf Adamson ◽  
Bertil Hamberger ◽  
Suad Efendić

Abstract. Hypothyroidism has been alleged to modulate insulin action and influence the secretion of growth hormone and catecholamines. We recently investigated the influence of hypothyroidism on glucose counterregulatory capacity and the hormonal responses to insulin-induced hypoglycaemia in 6 patients with primary hypothyroidism (age 32–52 years, TSH-values 66–200 mU/l). Hypoglycaemia was induced in the hypothyroid state and again when the subjects were euthyroid. After an overnight fast a constant rate infusion of insulin (2.4 U/h) was given for 4 h. Glucose was measured every 15 min and insulin, C-peptide, glucagon, epinephrine, norepinephrine, growth hormone and cortisol every 30 min for 5 h. During insulin infusion somewhat higher concentrations of the hormone were obtained in the hypothyroid state and simultaneously glucose levels were 0.5 mmol/l lower. As expected, basal norepinephrine levels were higher in hypothyroidism. However, no increase in circulating norepinephrine during hypoglycaemia was registered in the two experiments. The responses of counterregulatory hormones showed an enhanced response of cortisol, similar responses of growth hormone and epinephrine while the glucagon response was paradoxically impaired. Our findings suggest that hypothyroidism alters insulin metabolism, and that the glucagon response to hypoglycaemia is impaired in this condition.


2014 ◽  
Vol 75 (8) ◽  
pp. 716-721 ◽  
Author(s):  
Barbara Ambros ◽  
Jane Alcorn ◽  
Tanya Duke-Novakovski ◽  
Alexander Livingston ◽  
Patricia M. Dowling

2012 ◽  
Vol 171 (5) ◽  
pp. 125-125 ◽  
Author(s):  
M. del Mar Granados ◽  
J. Manuel Domínguez ◽  
A. Fernández-Sarmiento ◽  
F. Javier Funes ◽  
J. Morgaz ◽  
...  

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