Effect of a constant rate infusion of lidocaine on the quality of recovery from sevoflurane or isoflurane general anaesthesia in horses

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.

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Heated intravenous fluids alone fail to prevent hypothermia in cats under general anaesthesia

Journal of Feline Medicine and Surgery ◽

10.1177/1098612x16688990 ◽

2017 ◽

Vol 19 (12) ◽

pp. 1249-1253 ◽

Cited By ~ 2

Author(s):

Geraldine Jourdan ◽

Caroline Didier ◽

Erwan Chotard ◽

Sandra Jacques ◽

Patrick Verwaerde

Keyword(s):

General Anaesthesia ◽

Room Temperature ◽

Control Group ◽

Temperature Decrease ◽

Constant Rate Infusion ◽

Heating Device ◽

Intraoperative Hypothermia ◽

Constant Rate ◽

Heated Fluid ◽

Rate Infusion

Objectives The objective was to evaluate the clinical efficiacy of a constant rate infusion of heated fluid as the sole means of preventing intraoperative hypothermia in cats. Methods This randomised, prospective, clinical study was conducted at a university teaching veterinary hospital. Female cats (American Society of Anesthesiologists [ASA] grade I) undergoing elective surgery by laparotomy under general anaesthesia (acepromazine 0.05 mg/kg SC; morphine 0.2 mg/kg IV; propofol IV titrated, isoflurane 2% in 100% oxygen) were randomised in two groups. Both groups were infused with fluid (NaCl 0.9%, 5 ml/kg/h) either at room temperature (control group) or prewarmed at 43°C (warmed group) using an Astoflo Plus eco (Stihler Electronic) fluid heating device. No other heating device was used. Temperature, heart rate, respiratory rate and SpO2 were evaluated after induction (T0) and every 15 mins for 1 h (T15, T30, T45, T60). Mean arterial blood pressure was recorded every 30 mins (T0, T30 and T60). Results Thirty-four female cats (ASA grade I) were enrolled in the study. There was no difference in age, weight, propofol dose or room temperature (22.4 ± 1.1°C vs 22.0 ± 1.5°C; P = 0.363) between control and warmed groups, respectively. In both groups, oesophageal temperature significantly decreased during anaesthesia ( P <0.0001). The temperature decrease after 1 h was −3.6 ± 0.7°C in the warmed group and was not significantly different from the control group (−3.4 ± 0.7°C; P = 0.307). The slopes of the temperature decrease did not significantly differ between the two groups (–0.058 ± 0.013°C/min vs −0.060 ± 0.010°C/min for the control and warmed groups, respectively; P = 0.624). Conclusions and relevance This study provides clinical evidence that a constant rate infusion of heated fluid alone fails to prevent intraoperative hypothermia in cats. The low infusion rate (5 ml/kg/h) could partly explain the ineffectiveness of this active warming device in minimising or delaying the onset of intraoperative hypothermia.

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

Animals ◽

10.3390/ani11072081 ◽

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.

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The effect of a dexmedetomidine constant rate infusion on cardiopulmonary function and colonic blood flow in anesthetized, experimentally endotoxemic horses

Veterinary Anaesthesia and Analgesia ◽

10.1016/j.vaa.2020.07.017 ◽

2020 ◽

Vol 47 (6) ◽

pp. 855.e6

Author(s):

R. Hector ◽

M. Rezende ◽

B. Nelson ◽

E. Monnet

Keyword(s):

Blood Flow ◽

Constant Rate Infusion ◽

Cardiopulmonary Function ◽

Constant Rate ◽

Colonic Blood Flow ◽

Rate Infusion

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Counterregulation of insulin-induced hypoglycaemia in primary hypothyroidism

Acta Endocrinologica ◽

10.1530/acta.0.1110516 ◽

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.

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