Studies to Evaluate the Safety of Constant Rate Infusions of Dexmedetomidine, Ketamine and Lidocaine Alone or in Combination during Isoflurane Anesthesia in Horses

2021 ◽  
Author(s):  
Aswathy Gopinathan ◽  
Kiranjeet Singh ◽  
Sherin B. Sarangom ◽  
V. Ramya ◽  
P. Sangeetha ◽  
...  
Keyword(s):  
Significant Decline ◽  
Constant Rate Infusion ◽  
Anesthetic Depth ◽  
Isoflurane Anesthesia ◽  
Anesthetic Agents ◽  
Constant Rate ◽  
Sparing Effect ◽  
Rate Infusion ◽  
Operative Quality

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.

The isoflurane sparing effect of a medetomidine constant rate infusion in horses

2003 ◽  
Vol 30 (2) ◽  
pp. 92-93 ◽  
Author(s):  
K Neges ◽  
R Bettschart-Wolfensberger ◽  
J Müller ◽  
A Fürst ◽  
S Kästner
Keyword(s):  
Constant Rate Infusion ◽  
Constant Rate ◽  
Sparing Effect ◽  
Rate Infusion

scholarly journals Cardiorespiratory, Sedative and Antinociceptive Effects of a Medetomidine Constant Rate Infusion with Morphine, Ketamine or Both

Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 2081
Author(s):  
Lucas Troya-Portillo ◽  
Javier López-Sanromán ◽  
María Villalba-Orero ◽  
Isabel Santiago-Llorente
Keyword(s):  
Healthy Adult ◽  
Constant Rate Infusion ◽  
Treatment Groups ◽  
Constant Rate ◽  
Antinociceptive Effects ◽  
Negative Effect ◽  
Rate Infusion ◽  
Related Mortality ◽  
All Treatment

Standing surgery under sedation reduces anesthetic-related mortality in horses. Medetomidine, alone and combined with morphine in a constant rate infusion (CRI), has been described for standing surgery but their cardiorespiratory, sedative and antinociceptive effects have never been compared. The addition of ketamine could improve analgesia in these procedures with minimal cardiorespiratory consequences. The objectives were to compare the cardiorespiratory effects, quality of sedation, antinociception and ataxia produced by administration of a medetomidine-based CRI with morphine, ketamine or both, in standing horses. A prospective, blind, randomized crossover, experimental design with six healthy adult horses was performed, in which four treatments were administered to all horses with at least two weeks of washout period: medetomidine (M); medetomidine and ketamine (MK); medetomidine and morphine (MMo); and medetomidine, morphine and ketamine (MMoK). Dosages were the same in all treatment groups: medetomidine at 5 µg/kg bwt followed by 5 µg/kg bwt/h, ketamine at 0.4 mg/kg/h and morphine at 50 µg/kg bwt, followed by morphine 30 µg/kg bwt/h. Drug infusions were maintained for 120 min. Cardiorespiratory variables, sedation degree and antinociceptive effects were evaluated during the procedure. All combinations produced similar sedation and antinociceptive effects and no clinically relevant alterations in cardiorespiratory variables occurred. Medetomidine CRI combined with morphine, ketamine or both are suitable and safe protocols for standing sedation in horses and the addition of morphine and/or ketamine did not cause any negative effect but no improving effect on sedation and antinociception was detected.

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
Keyword(s):  
Observational Study ◽  
Depth Of Anesthesia ◽  
Constant Rate Infusion ◽  
Anesthetic Depth ◽  
Group 12 ◽  
Constant Rate ◽  
Balanced Anesthesia ◽  
Corneal Reflex ◽  
Limited Usefulness ◽  
Rate Infusion

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.

Counterregulation of insulin-induced hypoglycaemia in primary hypothyroidism

1986 ◽  
Vol 111 (4) ◽  
pp. 516-521
Author(s):  
Nina Clausen ◽  
Per-Eric Lins ◽  
Ulf Adamson ◽  
Bertil Hamberger ◽  
Suad Efendić
Keyword(s):  
Growth Hormone ◽  
Insulin Infusion ◽  
Primary Hypothyroidism ◽  
Constant Rate Infusion ◽  
Counterregulatory Hormones ◽  
Insulin Metabolism ◽  
Hormonal Responses ◽  
Glucose Levels ◽  
Constant Rate ◽  
Rate Infusion

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.

Sign in / Sign up

Export Citation Format

Share Document