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Ingrande J, Patel HH, Kendall D, Stefanska B, Alexander S, Bakhle M, Cirino G, Docherty JR, George CH, Insel PA, Ji Y, King BF, Lilley E, Panettieri RA, Ramage AG, Sobey CG, Stanford SC, Stephens G, Teixeira M, Vergnolle N, Ahluwalia A. Guidance for the use and reporting of anaesthetic agents in BJP manuscripts involving work with animals. Br J Pharmacol 2023; 180:255-263. [PMID: 36529953 DOI: 10.1111/bph.15992] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Scientists who plan to publish in the British Journal of Pharmacology (BJP) should read this article before undertaking studies utilising anaesthetics in mammalian animals. This editorial identifies certain gaps in the reporting of details on the use of anaesthetics in animal research studies published in the BJP. The editorial also provides guidance, based upon current best practices, for performing in vivo experiments that require anaesthesia. In addition, mechanisms of action and physiological impact of specific anaesthetic agents are discussed. Our goal is to identify best practices and to provide guidance on the information required for manuscripts submitted to the BJP that involve the use of anaesthetic agents in studies with experimental animals.
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Affiliation(s)
- Jerry Ingrande
- VA San Diego Healthcare System and University of California, San Diego, California, USA
| | - Hemal H Patel
- VA San Diego Healthcare System and University of California, San Diego, California, USA
| | | | | | | | | | | | | | | | - Paul A Insel
- University of California, San Diego, California, USA
| | - Yong Ji
- Nanjing Medical University, Nanjing, China
| | | | | | | | | | | | | | | | - Mauro Teixeira
- Federal University of Minas Gerais, Belo Horizonte, Brazil
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Hommuang K, Sattasathuchana P, Thengchaisri N. Effects of intranasal and intramuscular dexmedetomidine in cats receiving total intravenous propofol anesthesia. Vet World 2022; 15:1706-1713. [PMID: 36185505 PMCID: PMC9394123 DOI: 10.14202/vetworld.2022.1706-1713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 05/27/2022] [Indexed: 11/23/2022] Open
Abstract
Background and Aim: The efficacy of intranasal (IN) dexmedetomidine in cats as a premedication remains elusive. Thus, this study aimed to compare the perioperative and sparing effects of IN and intramuscular (IM) dexmedetomidine administration on propofol requirements for anesthetic induction in cats. Materials and Methods: This study randomly assigned 16 cats into two groups of IN or IM dexmedetomidine at 20 μg/kg. Sedation scores and side effects were recorded at time points of 0, 5, 10, 15, and 20 min after the dexmedetomidine administration. Anesthesia was induced with intravenous (IV) 1% propofol by titrating a bolus of 2 mg every 45 s and the total dose of the administered IV propofol to achieve endotracheal intubation was recorded. Results: Cats receiving IM dexmedetomidine were significantly associated with higher sedation scores. All cats were sedated at 20 min after premedication; however, the average composite sedation scores in the IN group were significantly lower than those in the IM group during premedication. Pre-operative side effects, including vomiting, were more frequently observed in the IN group (5 cats, 62.5%) than in the IM group (3 cats, 37.5%; p < 0.05). Higher body temperature (>1°F compared to baseline) was more frequently observed in the IN group (6 cats, 75.0%) than in the IM group (1 cat, 12.5%; p < 0.05). The dosage of required propofol in the IN group was significantly higher (1.1 ± 0.3 mg/kg) than that in the IM group (0.7 ± 0.2 mg/kg; p < 0.05). The duration of general anesthesia was comparable between the groups. Conclusion: IN dexmedetomidine produces moderate sedation and cats may have side effects, including vomiting and higher body temperature. Higher sparing effects of propofol were identified in the IM group compared with the IN group. Nonetheless, IN administration of dexmedetomidine provides a noninvasive alternative to the IM route.
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Affiliation(s)
- Kewvaree Hommuang
- Department of Companion Animal Clinical Science, Graduate Student in Veterinary Clinical Studies, Faculty of Veterinary Medicine, Kasetsart University, Bangkok, Thailand
| | - Panpicha Sattasathuchana
- Department of Companion Animal Clinical Sciences, Faculty of Veterinary Medicine, Kasetsart University, Bangkok, Thailand
| | - Naris Thengchaisri
- Department of Companion Animal Clinical Sciences, Faculty of Veterinary Medicine, Kasetsart University, Bangkok, Thailand; Tippimarn Veterinary Hospital, Chulabhorn Royal Academy, Nakhon Ratchasima, Thailand
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Mohsin S, Ahmad Ganaie Z, Kundi H, Ahmed MB, Riaz B, Khurshid Ahmed N, Anirudh Chunchu V, Haq A. Comparison of Fentanyl and Dexmedetomidine in Preventing an Increase in Heart Rate During Intubation Among Patients Undergoing General Anesthesia: A Meta-Analysis. Cureus 2022; 14:e26194. [PMID: 35891845 PMCID: PMC9306395 DOI: 10.7759/cureus.26194] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/21/2022] [Indexed: 11/24/2022] Open
Abstract
General anesthesia induction, tracheal intubation, extubation, and laryngoscopy are associated with specific hemodynamic changes. Tracheal intubation and laryngoscopy are related to sympathetic stimulation and lead to hypertension and tachycardia. Recent studies have shown that dexmedetomidine is safe and effective as it does not depress respiratory function. This meta-analysis aims to compare the efficacy of dexmedetomidine and fentanyl in preventing an increase in heart rate (HR) during intubation among patients undergoing general anesthesia. A systematic literature search was done using PubMed, Cochrane Library, and Embase to assess studies comparing the efficacy of dexmedetomidine and fentanyl in preventing an increase in HR during intubation. A meta-analysis was done utilizing a random-effects model, and mean differences of HR were determined between fentanyl and dexmedetomidine at baseline, one minute, five minutes, and 10 minutes of intubation. In this meta-analysis, eight randomized control trials were included, involving 548 patients (274 in the fentanyl group and 274 in the dexmedetomidine group). The findings showed that significant difference of HR was significantly lower in the dexmedetomidine group than the fentanyl group at one minute of intubation (mean difference = -8.46; P-value = 0.003), at five minutes of intubation (mean difference = -7.51; P-value = 0.001), and at 10 minutes of intubation (mean difference = -5.15; P-value = 0.030). In the current meta-analysis, dexmedetomidine was better than fentanyl in preventing tachycardia following endotracheal intubation. HR was significantly lower at one minute, five minutes, and 10 minutes after intubation in the dexmedetomidine group compared to the fentanyl group.
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Bharioke A, Munz M, Brignall A, Kosche G, Eizinger MF, Ledergerber N, Hillier D, Gross-Scherf B, Conzelmann KK, Macé E, Roska B. General anesthesia globally synchronizes activity selectively in layer 5 cortical pyramidal neurons. Neuron 2022; 110:2024-2040.e10. [PMID: 35452606 PMCID: PMC9235854 DOI: 10.1016/j.neuron.2022.03.032] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 10/30/2021] [Accepted: 03/28/2022] [Indexed: 12/27/2022]
Abstract
General anesthetics induce loss of consciousness, a global change in behavior. However, a corresponding global change in activity in the context of defined cortical cell types has not been identified. Here, we show that spontaneous activity of mouse layer 5 pyramidal neurons, but of no other cortical cell type, becomes consistently synchronized in vivo by different general anesthetics. This heightened neuronal synchrony is aperiodic, present across large distances, and absent in cortical neurons presynaptic to layer 5 pyramidal neurons. During the transition to and from anesthesia, changes in synchrony in layer 5 coincide with the loss and recovery of consciousness. Activity within both apical and basal dendrites is synchronous, but only basal dendrites’ activity is temporally locked to somatic activity. Given that layer 5 is a major cortical output, our results suggest that brain-wide synchrony in layer 5 pyramidal neurons may contribute to the loss of consciousness during general anesthesia. Activity of layer 5 PNs synchronizes globally in different anesthetics Other mouse cortical cell types show no consistent increase in synchrony Changes in layer 5 synchrony coincide with the loss and recovery of consciousness Basal, but not apical, layer 5 dendrites are in synchrony with somas
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Affiliation(s)
- Arjun Bharioke
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland; Department of Ophthalmology, University of Basel, Basel, Switzerland; Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Martin Munz
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland; Department of Ophthalmology, University of Basel, Basel, Switzerland; Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Alexandra Brignall
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland; Department of Ophthalmology, University of Basel, Basel, Switzerland
| | - Georg Kosche
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland; Department of Ophthalmology, University of Basel, Basel, Switzerland; Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Max Ferdinand Eizinger
- Max von Pettenkofer-Institute, Virology, Medical Faculty and Gene Center, Ludwig Maximilians University, Munich, Germany
| | - Nicole Ledergerber
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland; Department of Ophthalmology, University of Basel, Basel, Switzerland; Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Daniel Hillier
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland; Department of Ophthalmology, University of Basel, Basel, Switzerland; Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland; Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Budapest, Hungary
| | - Brigitte Gross-Scherf
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland; Department of Ophthalmology, University of Basel, Basel, Switzerland; Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Karl-Klaus Conzelmann
- Max von Pettenkofer-Institute, Virology, Medical Faculty and Gene Center, Ludwig Maximilians University, Munich, Germany
| | - Emilie Macé
- Brain-Wide Circuits for Behavior Research Group, Max Planck Institute of Neurobiology, Martinsried, Germany
| | - Botond Roska
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland; Department of Ophthalmology, University of Basel, Basel, Switzerland; Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.
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Alkaissi HR, Khudyakov A, Belligund P. Acute Colonic Pseudo-Obstruction Following the Use of Dexmedetomidine. Cureus 2021; 13:e19465. [PMID: 34912607 PMCID: PMC8665670 DOI: 10.7759/cureus.19465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/10/2021] [Indexed: 12/03/2022] Open
Abstract
Dexmedetomidine is a preferred agent for light sedation with minimal adverse effects. We report a case of acute colonic pseudo-obstruction following dexmedetomidine use in a patient with alcohol withdrawal. He was treated with benzodiazepines first to control the withdrawal symptoms, then escalated to dexmedetomidine once delirium tremens ensued. Later on, the patient developed abdominal distension and vomiting. Imaging showed dilated bowel loops and absence of peristalsis on ultrasound. Decompression with the nasogastric (NG) tube was done, with high output from the NG tube. Dexmedetomidine infusion was used twice, and once it was stopped, the NG tube output was reduced, with the resumption of gastrointestinal motility and improvement of the abdominal distension. Recent similar reports of functional intestinal obstruction following alpha-2 (α2) agonist use necessitate further studies of intestinal motility following dexmedetomidine use and awareness of the possible side effect of dexmedetomidine on intestinal motility.
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Affiliation(s)
- Hussam R Alkaissi
- Internal Medicine, State University of New York Downstate Medical Center, New York City, USA
| | - Aleksandr Khudyakov
- Pulmonology and Critical Care, Veterans Affairs New York Harbor Health Care (VA NYHHS), Brooklyn, USA
| | - Pooja Belligund
- Pulmonology and Critical Care, Veterans Affairs New York Harbor Health Care (VA NYHHS), Brooklyn, USA
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Karlsson JOG, Grundstrom N, Elwing H, Andersson RGG. The Fish Pigment Cell: An Alternative Model in Biomedical Research. Altern Lab Anim 2020. [DOI: 10.1177/026119299001800121.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Receptor-mediated pigment aggregation within pigment cells (chromatophores) of an isolated fish scale is an ideal model system for functional receptor studies. The superficial layer of the scale contains both dermal chromatophores and postganglionic sympathetic nerves. By means of stimulation of the nerves, or by addition of appropriate receptor agonists, it is possible to elicit pigment aggregation within the chromatophores. A single fish can contribute hundreds of scales, various pharmacological and biochemical experiments are easily carried out and the physiological response, i.e. pigment aggregation, is readily evaluated by the aid of a light microscope or a simple scale photometer.A denervation model, based on isolated scales, permits studies of factors involved in the sensitivity change, which typically takes place after experimental or pathological denervation.By using isolated fish scales it is quite simple to illustrate many biomedically important concepts, like receptor theory and nerve-effector cell communication. This makes the scale a very useful preparation in biomedical education.
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Affiliation(s)
| | - Nils Grundstrom
- Department of Pharmacology, University of Linköping, S-581 83 Linköping, Sweden
| | - Hans Elwing
- Laboratory of Applied Physics, University of Linköping, S-581 83 Linköping, Sweden
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Huuskonen V, Restitutti F, Honkavaara JM, Raekallio MR, Männikkö S, Scheinin M, Vainio OM. Investigation of the effects of vatinoxan on somatic and visceral antinociceptive efficacy of medetomidine in dogs. Am J Vet Res 2020; 81:299-308. [PMID: 32228259 DOI: 10.2460/ajvr.81.4.299] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine whether concurrent vatinoxan administration affects the antinociceptive efficacy of medetomidine in dogs at doses that provide circulating dexmedetomidine concentrations similar to those produced by medetomidine alone. ANIMALS 8 healthy Beagles. PROCEDURES Dogs received 3 IV treatments in a randomized crossover-design trial with a 2-week washout period between experiments (medetomidine [20 μg/kg], medetomidine [20 μg/kg] and vatinoxan [400 μg/kg], and medetomidine [40 μg/kg] and vatinoxan [800 μg/kg]; M20, M20V400, and M40V800, respectively). Sedation, visceral and somatic nociception, and plasma drug concentrations were assessed. Somatic and visceral nociception measurements and sedation scores were compared among treatments and over time. Sedation, visceral antinociception, and somatic antinociception effects of M20V400 and M40V800 were analyzed for noninferiority to effects of M20, and plasma drug concentration data were assessed for equivalence between treatments. RESULTS Plasma dexmedetomidine concentrations after administration of M20 and M40V800 were equivalent. Sedation scores, visceral nociception measurements, and somatic nociception measurements did not differ significantly among treatments within time points. Overall sedative effects of M20V400 and M40V800 and visceral antinociceptive effects of M40V800 were noninferior to those produced by M20. Somatic antinociception effects of M20V400 at 10 minutes and M40V800 at 10 and 55 minutes after injection were noninferior to those produced by M20. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested coadministration with vatinoxan did not substantially diminish visceral antinociceptive effects of medetomidine when plasma dexmedetomidine concentrations were equivalent to those produced by medetomidine alone. For somatic antinociception, noninferiority of treatments was detected at some time points.
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Comparing the effect of dexmedetomidine and labetalol on hemodynamic variables in patients undergoing microlaryngoscopy. Eur Arch Otorhinolaryngol 2019; 276:2513-2517. [PMID: 31222586 DOI: 10.1007/s00405-019-05521-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 06/14/2019] [Indexed: 12/19/2022]
Abstract
INTRODUCTION This study was conducted to compare the effect of dexmedetomidine and labetalol on hemodynamic variables in patients undergoing microlaryngoscopy. MATERIAL AND METHODS In this randomized clinical trial study 70 patients undergoing microlaryngoscopy were involved. The patients were randomly assigned into two groups. Patients in dexmedetomidine group received 0.5 μg/kg of dexmedetomidine diluted in 100 ml of saline solution and the patients in the second group received 0.25 mg/kg of labetalol before anesthesia induction. At the beginning of the surgery, dexmedetomidine was infused at the dose of 0.4 μg/kg/h in the dexmedetomidine group, and labetalol at the dose of 1.8 mg/kg/h in the labetalol group. Patients' systolic blood pressure, diastolic blood pressure, mean arterial blood pressure and heart rate at different times and anesthesia and surgery duration, recovery time and dose of prescribed propofol were recorded and compared between two groups. RESULTS There was a significant difference in mean systolic blood pressure, mean diastolic blood pressure, mean arterial blood pressure and mean heart rate between two groups at different times (p value < 0.05). CONCLUSION The results of this study indicated that dexmedetomidine had higher efficacy, compared to labetalol, in reducing diastolic blood pressure, systolic blood pressure, heart rate, and mean arterial blood pressure following microlaryngoscopy.
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Kamali A, Taghizadeh M, Esfandiar M, Akhtari AS. A Comparison of the Effects of Dexmedetomidine and Propofol in Controlling the Hemodynamic Responses after Intubation: A Double-Blind, Randomized, Clinical Trial Study. Open Access Maced J Med Sci 2018; 6:2045-2050. [PMID: 30559858 PMCID: PMC6290445 DOI: 10.3889/oamjms.2018.385] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 09/09/2018] [Accepted: 09/11/2018] [Indexed: 12/03/2022] Open
Abstract
AIM: This study aimed to compare the effects of dexmedetomidine and propofol in controlling the hemodynamic response following intubation of patients’ candidate intubation in the emergency department METHODS: A total of 114 patients were randomly assigned to one of 2 groups to receive one of the following treatments: dexmedetomidine 0.4 µg/kg (Group D, n = 57) and propofol 1–1.5 mg/kg/h (Group P, n = 57). Hemodynamic data such as the systolic blood pressure, diastolic blood pressure, arterial oxygen saturation and heart rate (HR) were recorded from the entrance to operation room to 5, 10 and 15 min after tracheal intubation RESULTS: Compared with group D, group P exhibited increases in mean arterial blood pressure (MAP), and systolic blood pressure significantly at all times and immediately after the endotracheal intubation. Moreover, the mean diastolic blood pressure changes due to tracheal intubation in group P were significantly more than group D immediately after the intubation. Furthermore, the mean heart rate changes immediately and 5 min after tracheal intubation was significantly higher in group P CONCLUSION: Our data suggest that the benefits of dexmedetomidine more than propofol in hemodynamic stability because propofol was associated with more variability in systolic/diastolic blood pressure, HR and MAP after endotracheal intubation.
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Affiliation(s)
- Alireza Kamali
- Department of Anesthesiology, Arak University of Medical Sciences, Arak, Iran
| | - Mehrdad Taghizadeh
- Department of Emergency, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohtaram Esfandiar
- Department of Emergency, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Amin Shams Akhtari
- Department of Emergency, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Neil L, Patel A. Effect of Dexmedetomidine Versus Fentanyl on Haemodynamic Response to Patients Undergoing Elective Laparoscopic Surgery: A Double Blinded Randomized Controlled Study. J Clin Diagn Res 2017; 11:UC01-UC04. [PMID: 28571235 PMCID: PMC5449881 DOI: 10.7860/jcdr/2017/24152.9563] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 01/02/2017] [Indexed: 11/24/2022]
Abstract
INTRODUCTION Dexmedetomidine, an α2 agonist, can be used as an adjuvant in general anaesthesia as it attenuates the stress response to various noxious stimuli and helps in maintaining the perioperative haemodynamic stability along with sedation and not causing any significant respiratory depression in the postoperative period. AIM To study the difference in haemodynamic responses of dexmedetomidine and fentanyl in patients undergoing laparoscopic surgery. MATERIALS AND METHODS Sixty patients were divided into two groups of 30 each randomly. In Group F, fentanyl 0.5 μg/kg as loading dose over 10 minutes prior to induction followed by 0.2-0.7 μg/kg/hr as maintenance dose and in Group D, Dexmedetomidine 0.5 μg/kg as loading dose over 10 minutes prior to induction followed by 0.2 μg/kg/hr-0.7 μg/kg/hr as maintenance dose till surgery was over. Haemodynamic variables and Visual Analogue Scale (VAS) scores were recorded continuously. Postoperative sedation and recovery were assessed by modified Ramsay sedation score. RESULTS Systolic Blood Pressure (SBP) fell by 9% in Group-D as compared to no fall in Group F during intubation. After intubation, 9% increase is seen in Group D v/s 19% in Group F. During the period of pneumoperitoneum upto 5 minutes post extubation, the SBP in Group D was significantly lower as compared to Group F rest duration, the difference was not significant between both groups. Heart Rate (HR) remained stable throughout the study except at laryngoscopy when it rose. Heart rate was similar in both groups at intubation, decreased by 3.51% in Group D as compare to 11.11% rise in Group F. Post intubate on, heart rate fell by 2% in Group D vs 15% rise in Group F. Diastolic Blood Pressure (DBP) remained higher than baseline than throughout the study. After intubation, 3% higher in Group D where as 15% in Group F increase was seen. In intraoperative period the difference between both groups was not significant. There was significant difference between two groups at 10 minutes, 45 minutes of pneumoperitoneum. End Tidal CO2 (ETCO2) was similar in both groups. CONCLUSION Dexmedetomidine is better drug as compared to fentanyl for maintaining the haemodynamic response during intubation and intraoperative period.
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Affiliation(s)
- Lovina Neil
- Resident, Department of Anaesthesiology, Sterling Hospital, Ahmedabad, Gujarat, India
| | - Ashok Patel
- Head, Department of Anaesthesia, Sterling Hospital, Ahmedabad, Gujarat, India
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Shah Z, Hu ML, Qiu ZY, Zhou FY, Zeng J, Wan J, Wang SW, Zhang W, Ding MX. Physiologic and biochemical effects of electroacupuncture combined with intramuscular administration of dexmedetomidine to provide analgesia in goats. Am J Vet Res 2016; 77:252-9. [PMID: 26919595 DOI: 10.2460/ajvr.77.3.252] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To investigate physiologic and biochemical effects of electroacupuncture and dexmedetomidine administration to goats. ANIMALS 30 healthy adult goats. PROCEDURES Goats were allotted to 5 groups (6 goats/group) and received electroacupuncture, dexmedetomidine (5 or 20 μg/kg, IM), electroacupuncture plus dexmedetomidine (5 μg/kg, IM), or saline (0.9% NaCl) solution (IM [control treatment]). Pain threshold, cardiorespiratory effects, rectal temperature, and hematologic and biochemical variables were assessed. RESULTS Dexmedetomidine (20 μg/kg) increased pain threshold and decreased heart rate, respiratory rate, and rectal temperature. Pain threshold of goats receiving electroacupuncture plus dexmedetomidine (5 μg/kg) was higher than that of goats receiving electroacupuncture or of goats receiving dexmedetomidine at 5 μg/kg at 30 minutes, but did not differ from that of goats receiving dexmedetomidine at 20 μg/kg. Compared with goats administered dexmedetomidine at 20 μg/kg, goats receiving electroacupuncture plus dexmedetomidine at 5 μg/kg had a higher heart rate from 30 to 60 minutes and a higher respiratory rate from 5 to 60 minutes. Electroacupuncture plus dexmedetomidine (5 μg/kg) did not affect rectal temperature. Serum glucose concentrations of goats receiving electroacupuncture plus dexmedetomidine (5 μg/kg) were higher than for goats receiving dexmedetomidine at 5 μg/kg at 30 minutes but not for goats receiving dexmedetomidine at 20 μg/kg. Creatinine and BUN concentrations, alanine or aspartate aminotransferase activities, and hematologic variables of treated goats did not change. CONCLUSIONS AND CLINICAL RELEVANCE Electroacupuncture in combination with a low dose of dexmedetomidine (5 μg/kg, IM) administered to goats provided antinociception.
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Wendt I, Backhaus T, Blanck H, Arrhenius Å. The toxicity of the three antifouling biocides DCOIT, TPBP and medetomidine to the marine pelagic copepod Acartia tonsa. ECOTOXICOLOGY (LONDON, ENGLAND) 2016; 25:871-879. [PMID: 26984312 DOI: 10.1007/s10646-016-1644-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/04/2016] [Indexed: 06/05/2023]
Abstract
Copepods, the largest group of pelagic grazers, are at risk from exposure to antifouling biocides. This study investigated the toxicity of the antifouling biocides 4,5-dichloro-2-octyl-1,2-thiazol-3(2H)-one (DCOIT), triphenylborane pyridine (TPBP) and 4-[1-(2,3-dimethylphenyl)ethyl]-1H-imidazole (medetomidine) to the copepod Acartia tonsa, using mortality and egg production as endpoints. The toxicity ranking for mortality was as follows: DCOIT (LC50 57 nmol l(-1)) = TPBP (LC50 56 nmol l(-1)) > medetomidine (LC50 241 nmol l(-1)). Egg production was more sensitive than mortality to TPBP (EC50 3.2 nmol l(-1)), while DCOIT and medetomidine inhibited egg production at roughly the same concentrations (72 and 186 nmol l(-1) respectively). Furthermore, TPBP seems to affect egg hatching directly which was not the case for DCOIT and medetomidine. DCOIT and medetomidine might pose an environmental risk as they have been reported to occur in different exposure scenarios or analytical surveys at concentrations only 2-3 times lower than the respective EC10. Reported environmental concentrations of TPBP are few but clearly lower than the EC10 values reported here, suggesting current risk of TPBP to copepods to be moderate.
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Affiliation(s)
- Ida Wendt
- Swedish Institute for the Marine Environment, Gothenburg, Sweden
| | - Thomas Backhaus
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
| | - Hans Blanck
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
| | - Åsa Arrhenius
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden.
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Bennett RC, Salla KM, Raekallio MR, Hänninen L, Rinne VM, Scheinin M, Vainio OM. Effects of MK-467 on the antinociceptive and sedative actions and pharmacokinetics of medetomidine in dogs. J Vet Pharmacol Ther 2016; 39:336-43. [DOI: 10.1111/jvp.12292] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 12/03/2015] [Indexed: 11/29/2022]
Affiliation(s)
- R. C. Bennett
- University Veterinary Hospital; UCD; Dublin Ireland
- Department of Equine and Small Animal Medicine; University of Helsinki; Helsinki Finland
| | - K. M. Salla
- Department of Equine and Small Animal Medicine; University of Helsinki; Helsinki Finland
| | - M. R. Raekallio
- Department of Equine and Small Animal Medicine; University of Helsinki; Helsinki Finland
| | - L. Hänninen
- Department of Production Animal Medicine; University of Helsinki; Helsinki Finland
| | - V. M. Rinne
- Department of Pharmacology; Drug Development and Therapeutics; University of Turku and Unit of Clinical Pharmacology; Turku University Hospital; Turku Finland
| | - M. Scheinin
- Department of Pharmacology; Drug Development and Therapeutics; University of Turku and Unit of Clinical Pharmacology; Turku University Hospital; Turku Finland
| | - O. M. Vainio
- Department of Equine and Small Animal Medicine; University of Helsinki; Helsinki Finland
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Fares KM, Mohamed SAE, Abd El-Rahman AM, Mohamed AA, Amin AT. Efficacy and safety of intraperitoneal dexmedetomidine with bupivacaine in laparoscopic colorectal cancer surgery, a randomized trial. PAIN MEDICINE 2015; 16:1186-94. [PMID: 25585502 DOI: 10.1111/pme.12687] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Our objective is to investigate the efficacy and safety of intraperitoneal dexmedetomidine (Dex) combined with bupivacaine in patients undergoing laparoscopic colorectal cancer surgery. DESIGN Randomized double-blind study. SETTING Academic medical center. PATIENTS AND METHODS Forty-five patients scheduled for laparoscopic colorectal cancer surgery were randomly assigned for intraperitoneal administration of 50 mL saline (control group; GI, n = 15), 50 mL bupivacaine 0.25% (125 mg; GII, n = 15), or 50 mL bupivacaine 0.25% (125 mg) +1 μg/kg Dex (GIII, n = 15). Patients were assessed during the first 24 hours postoperatively for hemodynamics, visual analogue scale (VAS), time to first request of analgesia, total analgesic consumption, shoulder pain, and side effects. RESULTS A significant reduction was observed in VAS in GIII at base line, 2, 4, and 24 hours postoperatively in comparison to GI and GII (P < 0.05). The time to first analgesic requirement was significantly prolonged in GIII (P < 0.05). The mean total consumption of rescue analgesia was significantly reduced in GIII. CONCLUSION We conclude that intraperitoneal administration of Dex 1 μg/kg combined with bupivacaine improves the quality and the duration of postoperative analgesia and provides an analgesic sparing effect compared to bupivacaine alone without significant adverse effects in patients undergoing laparoscopic colorectal cancer surgery.
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Affiliation(s)
- Khaled Mohamed Fares
- Department of Anesthesia, Intensive Care, and Pain Management, South Egypt Cancer Institute, Assiut, Egypt
| | - Sahar Abd-Elbaky Mohamed
- Department of Anesthesia, Intensive Care, and Pain Management, South Egypt Cancer Institute, Assiut, Egypt
| | | | - Ashraf Amin Mohamed
- Department of Anesthesia, Intensive Care, and Pain Management, South Egypt Cancer Institute, Assiut, Egypt
| | - Anwar Tawfik Amin
- Department of Surgical Oncology, South Egypt Cancer Institute, Assiut University, Assiut, Egypt
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Gozalo-Marcilla M, Gasthuys F, Schauvliege S. Partial intravenous anaesthesia in the horse: a review of intravenous agents used to supplement equine inhalation anaesthesia. Part 2: opioids and alpha-2 adrenoceptor agonists. Vet Anaesth Analg 2015; 42:1-16. [DOI: 10.1111/vaa.12196] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Accepted: 09/13/2013] [Indexed: 01/04/2023]
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16
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Arrhenius Å, Backhaus T, Hilvarsson A, Wendt I, Zgrundo A, Blanck H. A novel bioassay for evaluating the efficacy of biocides to inhibit settling and early establishment of marine biofilms. MARINE POLLUTION BULLETIN 2014; 87:292-299. [PMID: 25150894 DOI: 10.1016/j.marpolbul.2014.07.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 07/01/2014] [Accepted: 07/06/2014] [Indexed: 05/21/2023]
Abstract
This paper presents a novel assay that allows a quick and robust assessment of the effects of biocides on the initial settling and establishment of marine photoautotrophic biofilms including the multitude of indigenous fouling organisms. Briefly, biofilms are established in the field, sampled, comminuted and re-settled on clean surfaces, after 72h chlorophyll a is measured as an integrating endpoint to reflect both settling and growth. Eight antifoulants were used to evaluate the assay. Efficacy ranking, based on EC98 values from most to least efficacious compound is: copper pyrithione>TPBP>DCOIT>tolylfluanid>zinc pyrithione>medetomidine>copper (Cu(2+)), while ecotoxicological ranking (based on EC10 values) is irgarol, copper pyrithione>zinc pyrithione>TPBP>tolylfluanid>DCOIT>copper (Cu(2+))>medetomidine. The algaecide irgarol did not cause full inhibition. Instead the inhibition leveled out at 95% effect at 30 nmoll(-)(1), a concentration that was clearly lower than for any other of the tested biocides.
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Affiliation(s)
- Åsa Arrhenius
- University of Gothenburg, Department of Biological and Environmental Sciences, Box 461, SE-405 30 Gothenburg, Sweden.
| | - Thomas Backhaus
- University of Gothenburg, Department of Biological and Environmental Sciences, Box 461, SE-405 30 Gothenburg, Sweden.
| | - Annelie Hilvarsson
- University of Gothenburg, Department of Biological and Environmental Sciences, Box 461, SE-405 30 Gothenburg, Sweden.
| | - Ida Wendt
- University of Gothenburg, Department of Biological and Environmental Sciences, Box 461, SE-405 30 Gothenburg, Sweden.
| | - Aleksandra Zgrundo
- University of Gdansk, Institute of Oceanography, Al. Pilsudskiego 46, 81-378 Gdynia, Poland.
| | - Hans Blanck
- University of Gothenburg, Department of Biological and Environmental Sciences, Box 461, SE-405 30 Gothenburg, Sweden.
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Busettini C, Frölich MA. Effects of mild to moderate sedation on saccadic eye movements. Behav Brain Res 2014; 272:286-302. [PMID: 25026096 DOI: 10.1016/j.bbr.2014.07.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Revised: 07/02/2014] [Accepted: 07/07/2014] [Indexed: 10/25/2022]
Abstract
Sedatives alter the metrics of saccadic eye movements. If these effects are nonspecific consequences of sedation, like drowsiness and loss of attention to the task, or differ between sedatives is still unresolved. A placebo-controlled multi-step infusion of one of three sedatives, propofol or midazolam, both GABA-A agonists, or dexmedetedomidine, an α2-adrenergic agonist, was adopted to compare the effects of these three drugs in exactly the same experimental conditions. 60 healthy human volunteers, randomly divided in 4 groups, participated in the study. Each infusion step, delivered by a computer-controlled infusion pump, lasted 20min. During the last 10min of each step, the subject executed a saccadic task. Target concentration was doubled at each step. This block was repeated until the subject was too sedated to continue or for a maximum of 6 blocks. Subjects were unaware which infusion they were receiving. A video eye tracker was used to record the movements of the right eye. Saccadic parameters were modeled as a function of block number, estimated sedative plasma concentration, and subjective evaluation of sedation. Propofol and midazolam had strong effects on the dynamics and latency of the saccades. Midazolam, and to a less extent, propofol, caused saccades to become increasingly hypometric. Dexmedetedomidine had less impact on saccadic metrics and presented no changes in saccadic gain. Suppression of the sympathetic system associated with dexmedetomidine has different effects on eye movements from the increased activity of the inhibitory GABA-A receptors by propofol and midazolam even when the subjects reported similar sedation level.
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Affiliation(s)
- C Busettini
- Department of Vision Sciences and Vision Science Research Center, University of Alabama at Birmingham, Birmingham, AL 35294-4390, USA.
| | - M A Frölich
- Department of Anesthesiology, University of Alabama at Birmingham, Birmingham, AL 35294-6810, USA
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Salla K, Restitutti F, Vainionpää M, Junnila J, Honkavaara J, Kuusela E, Raekallio M, Vainio O. The cardiopulmonary effects of a peripheral alpha-2-adrenoceptor antagonist, MK-467, in dogs sedated with a combination of medetomidine and butorphanol. Vet Anaesth Analg 2014; 41:567-74. [PMID: 24674053 DOI: 10.1111/vaa.12158] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 07/23/2013] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To compare the cardiopulmonary effects of intravenous (IV) and intramuscular (IM) medetomidine and butorphanol with or without MK-467. STUDY DESIGN Prospective, randomized experimental cross-over. ANIMALS Eight purpose-bred beagles (two females, six males), 3-4 years old and weighing 14.5 ±1.6 kg (mean ± SD). METHODS All dogs received four different treatments as follows: medetomidine 20 μg kg(-1) and butorphanol tartrate 0.1 mg kg(-1) IV and IM (MB), and MB combined with MK-467,500 μg kg(-1) (MBMK) IV and IM. Heart rate (HR), arterial blood pressures (SAP, MAP, DAP), central venous pressure (CVP), cardiac output, respiratory rate (fR ), rectal temperature (RT) were measured and arterial blood samples were obtained for gas analysis at baseline and at 3, 10, 20, 30, 45 and 60 minutes after drug administration. The cardiac index (CI), systemic vascular resistance index (SVRI) and oxygen delivery index (DO2 I) were calculated. After the follow-up period atipamezole 50 μg kg(-1) IM was given to reverse sedation. RESULTS HR, CI and DO2 I were significantly higher with MBMK after both IV and IM administration. Similarly, SAP, MAP, DAP, CVP, SVRI and RT were significantly lower after MBMK than with MB. There were no differences in fR between treatments, but arterial partial pressure of oxygen decreased transiently after all treatments. Recoveries were uneventful following atipamezole administration after all treatments. CONCLUSIONS AND CLINICAL RELEVANCE MK-467 attenuated the cardiovascular effects of a medetomidine-butorphanol combination after IV and IM administration.
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Affiliation(s)
- Kati Salla
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
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Patel CR, Engineer SR, Shah BJ, Madhu S. The effect of dexmedetomidine continuous infusion as an adjuvant to general anesthesia on sevoflurane requirements: A study based on entropy analysis. J Anaesthesiol Clin Pharmacol 2013; 29:318-22. [PMID: 24106354 PMCID: PMC3788228 DOI: 10.4103/0970-9185.117066] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Background: Dexmedetomidine, a α2 agonist as an adjuvant in general anesthesia, has anesthetic and analgesic-sparing property. Aims: To evaluate the effect of continuous infusion of dexmedetomidine alone, without use of opioids, on requirement of sevoflurane during general anesthesia with continuous monitoring of depth of anesthesia by entropy analysis. Materials and Methods: Sixty patients were randomly divided into 2 groups of 30 each. In group A, fentanyl 2 mcg/kg was given while in group B, dexmedetomidine was given intravenously as loading dose of 1 mcg/kg over 10 min prior to induction. After induction with thiopentone in group B, dexmedetomidine was given as infusion at a dose of 0.2-0.8 mcg/kg. Sevoflurane was used as inhalation agent in both groups. Hemodynamic variables, sevoflurane inspired fraction (FIsevo), sevoflurane expired fraction (ETsevo), and entropy (Response entropy and state entropy) were continuously recorded. Statistical analysis was done by unpaired student's t-test and Chi-square test for continuous and categorical variables, respectively. A P-value < 0.05 was considered significant. Results: The use of dexmedetomidine with sevoflurane was associated with a statistical significant decrease in ETsevo at 5 minutes post-intubation (1.49 ± 0.11) and 60 minutes post-intubation (1.11 ±0.28) as compared to the group A [1.73 ±0.30 (5 minutes); 1.68 ±0.50 (60 minutes)]. There was an average 21.5% decrease in ETsevo in group B as compared to group A. Conclusions: Dexmedetomidine, as an adjuvant in general anesthesia, decreases requirement of sevoflurane for maintaining adequate depth of anesthesia.
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20
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Wendt I, Arrhenius Å, Backhaus T, Hilvarsson A, Holm K, Langford K, Tunovic T, Blanck H. Effects of five antifouling biocides on settlement and growth of zoospores from the marine macroalga Ulva lactuca L. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2013; 91:426-432. [PMID: 23846394 DOI: 10.1007/s00128-013-1057-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2013] [Accepted: 07/01/2013] [Indexed: 06/02/2023]
Abstract
Antifouling biocides are found in the marine ecosystem were they can affect non-target organisms. In this study the effects of five antifouling biocides on the settlement and growth of Ulva lactuca zoospores were investigated. The biocides investigated were copper (Cu(2+)), 4,5-dichloro-2-n-octyl-3(2H)-isothiazolone (DCOIT), triphenylborane pyridine (TPBP), tolylfluanid and medetomidine. Full concentration-response curves where determined for each compound. EC50 values were determined for copper, DCOIT, TPBP and tolylfluanid, all of which inhibited settlement and growth in a concentration dependent manner with the following toxicity ranking; tolylfluanid (EC50 80 nmol L(-1)) ~ DCOIT (EC50 83 nmol L(-1)) > TPBP (EC50 400 nmol L(-1)) > Cu(2+) (EC50 2,000 nmol L(-1)). Medetomidine inhibited settlement and growth only at the extreme concentration of 100,000 nmol L(-1) (93% effect). The low toxicity is possibly a consequence of a lack of receptors that medetomidine can bind to in the U. lactuca zoospores.
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Affiliation(s)
- Ida Wendt
- Department of Biological and Environmental Sciences, University of Gothenburg, Box 461, Gothenburg, 405 30, Sweden,
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21
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Guedes AGP, Rude EP. Effects of pre–operative administration of medetomidine on plasma insulin and glucose concentrations in healthy dogs and dogs with insulinoma. Vet Anaesth Analg 2013; 40:472-81. [DOI: 10.1111/vaa.12047] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Accepted: 07/26/2012] [Indexed: 11/28/2022]
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Patel CR, Engineer SR, Shah BJ, Madhu S. Effect of intravenous infusion of dexmedetomidine on perioperative haemodynamic changes and postoperative recovery: A study with entropy analysis. Indian J Anaesth 2013; 56:542-6. [PMID: 23325938 PMCID: PMC3546240 DOI: 10.4103/0019-5049.104571] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Background: Dexmedetomidine, an α2 agonist, when used as an adjuvant in general anaesthesia attenuates stress response to various noxious stimuli, maintains perioperative haemodynamic stability and provides sedation without significant respiratory depression postoperatively. Methods: Sixty patients were randomly divided into two groups of 30 each. In group A, fentanyl 2 μg/kg and in group B dexmedetomidine were given intravenously as loading dose of 1 μg/kg over 10 min prior to induction. After induction with thiopentone, in group B, dexmedetomidine was given as infusion at a dose of 0.2–0.8 μg/kg. Sevoflurane was used as inhalation agent in both groups. Haemodynamic variables and entropy (response entropy and state entropy) were recorded continuously. Postoperative sedation and recovery were assessed by sedation score and modified Aldrete's score, respectively. Results: Dexmedetomidine significantly attenuates stress response at intubation with lesser increase in heart rate (10% vs. 17%), systolic blood pressure (6% vs. 23%) and diastolic blood pressure (7% vs. 20%) as compared to the control group (P<0.05). Intraoperatively, an average of 8% fall in systolic blood pressure and 8.16% fall in diastolic pressure in the test group as compared to 3.6% rise in systolic and 3.3% in diastolic pressure of the control group was observed. Postoperatively, the test group showed significant sedation at 2 h as compared to the control group (P=0.00) and recovery was better in the control group for the first 2 h post extubation. Conclusion: Dexmedetomidine attenuates various stress responses during surgery and maintains the haemodynamic stability when used as an adjuvant in general anaesthesia. Also, the sedative action of dexmedetomidine delays recovery for the first few hours post extubation.
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Affiliation(s)
- Chirag Ramanlal Patel
- Department of Anesthesia, B. J. Medical College, Civil Hospital, Ahmedabad, Gujarat, India
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23
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Panda BK, Singh P, Marne S, Pawar A, Keniya V, Ladi S, Swami S. A comparison study of Dexmedetomidine Vs Clonidine for sympathoadrenal response, perioperative drug requirements and cost analysis. ASIAN PACIFIC JOURNAL OF TROPICAL DISEASE 2012. [DOI: 10.1016/s2222-1808(12)60271-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Harrison KA, Robertson SA, Levy JK, Isaza NM. Evaluation of medetomidine, ketamine and buprenorphine for neutering feral cats. J Feline Med Surg 2011; 13:896-902. [PMID: 21885310 PMCID: PMC10832978 DOI: 10.1016/j.jfms.2011.06.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/10/2011] [Indexed: 11/16/2022]
Abstract
A combination of medetomidine (M, 100 μg/kg), ketamine (K, 10 mg/kg) and buprenorphine (B, 10 μg/kg), administered by intramuscular injection, was evaluated for spaying and castration (neutering) of feral cats (n = 101). Eleven animals (11%) required supplemental anesthesia (isoflurane by mask) to maintain an adequate plane of surgical anesthesia. Atipamezole (A, 125 μg/kg) was administered subcutaneously at the completion of surgery. All cats recovered from surgery and were released the following day. A hemoglobin saturation (SpO(2)) value of < 95% was recorded at least once during anesthesia in all cats. This MKB combination can be used in a feral cat sterilization clinic, but isoflurane supplementation may be necessary. Further research is indicated to determine the clinical significance of the low SpO(2) values associated with this anesthetic regimen.
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Affiliation(s)
- Kelly A Harrison
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, PO Box 100136, Gainesville, FL 32610-0136, USA
| | - Sheilah A Robertson
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, PO Box 100136, Gainesville, FL 32610-0136, USA
| | - Julie K Levy
- Maddie's Shelter Medicine Program, College of Veterinary Medicine, University of Florida, USA
| | - Natalie M Isaza
- Merial Shelter Medicine Clerkship, Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, USA
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Keniya VM, Ladi S, Naphade R. Dexmedetomidine attenuates sympathoadrenal response to tracheal intubation and reduces perioperative anaesthetic requirement. Indian J Anaesth 2011; 55:352-7. [PMID: 22013250 PMCID: PMC3190508 DOI: 10.4103/0019-5049.84846] [Citation(s) in RCA: 122] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Background: Dexmedetomidine, an α-2 adrenoreceptor agonist, is gaining popularity for its sympatholytic, sedative, anaesthetic sparing and haemodynamic stabilising properties without significant respiratory depression. Methods: We assessed the efficacy of dexmedetomidine in attenuating sympathoadrenal response to tracheal intubation and analysed reduction in intraoperative anaesthetic requirement. Sixty patients scheduled for elective surgery of more than 3 hours were randomly selected. Control group received isoflurane–opioid and study group received isoflurane–opioid-dexmedetomidine anaesthesia. Dexmedetomidine infusion in a dose of 1 μg/kg was given over 10 min before the induction of anaesthesia and was continued in a dose of 0.2–0.7 μg/kg/Hr until skin closure. All patients were induced with thiopentone, fentanyl and vecuronium. Haemodynamic variables were continuously recorded. Results: The need for thiopentone and isoflurane was decreased by 30% and 32%, respectively, in the dexmedetomidine group as compared to the control group. After tracheal intubation, maximal average increase was 8% in systolic and 11% in diastolic blood pressure in dexmedetomidine group, as compared to 40% and 25%, respectively, in the control group. Similarly, average increase in heart rate was 7% and 21% in the dexmedetomidine and control groups, respectively. Fentanyl requirement during the operation was 100±10 μg in the control group and 60±10 μg in the dexmedetomidine group. Conclusion: Perioperative infusion of dexmedetomidine is effective in attenuating sympathoadrenal response to tracheal intubation. It has significant anaesthetic and opioid sparing effect.
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Affiliation(s)
- Varshali M Keniya
- Department of Anesthesia, Bharati Vidyapeeth University Medical College, Pune, Maharashtra, India
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Musk GC, Netto JD, Maker GL, Trengove RD. Transplacental transfer of medetomidine and ketamine in pregnant ewes. Lab Anim 2011; 46:46-50. [PMID: 22008849 DOI: 10.1258/la.2011.010179] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The extent of placental transfer of medetomidine and ketamine is unknown in pregnant ewes. Date-mated singleton (n = 8) and twin (n = 8) pregnant merino cross ewes were anaesthetized for Caesarean delivery of preterm lamb fetuses. A combination of medetomidine (20 μg/kg) and ketamine (10 mg/kg) was administered by intravenous injection and surgery performed immediately thereafter. Blood samples were collected from the ewe at one, five and 10 min after intravenous injection and from the umbilical vein of the fetus at delivery. Non-pregnant ewes were also anaesthetized (n = 8). There was no difference in the plasma concentration of medetomidine or ketamine when comparing singleton and twin ewes or pregnant and non-pregnant ewes for the short duration of the study. Fetal plasma concentrations of each drug were comparable to the maternal concentrations at the same time. We conclude that both drugs cross the placenta readily and provide anaesthesia and analgesia for the fetus when it is delivered.
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Affiliation(s)
- G C Musk
- School of Veterinary and Biomedical Sciences, Murdoch University, Western Australia 6150, Australia.
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Lee JY, Jee HC, Jeong SM, Park CS, Kim MC. Comparison of anaesthetic and cardiorespiratory effects of xylazine or medetomidine in combination with tiletamine/zolazepam in pigs. Vet Rec 2010; 167:245-9. [PMID: 20710032 DOI: 10.1136/vr.c3611] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Two different combinations of anaesthetics were evaluated and compared in a prospective randomised crossover experimental study in pigs. One of the two combinations was administered intramuscularly to each of six Landrace x Yorkshire mixed-breed pigs. The combinations were: 2.2 mg/kg xylazine and 4.4 mg/kg tiletamine/zolazepam (2.2 mg/kg tiletamine plus 2.2 mg/kg zolazepam) (XTZ); and 0.04 mg/kg medetomidine and 4.4 mg/kg tiletamine/zolazepam (MTZ). The anaesthesia and recovery times, score for anaesthetic effect and cardiopulmonary parameters were recorded for each pig. Anaesthesia was successfully induced in all of the pigs. Both drug combinations provided smooth induction and good immobilisation, and their anaesthetic effects were similar. In both treatment groups, the mean heart rate decreased significantly five minutes after the drugs were administered and remained consistent for 70 minutes, with no significant difference between the XTZ and MTZ groups. However, there were differences in cardiopulmonary effects between the groups. The arterial pressure was significantly higher in the MTZ group than in the XTZ group. The initial hypertension associated with medetomidine was more marked than the initial hypertension associated with xylazine. Arterial oxygen partial pressure and arterial oxygen saturation decreased significantly from baseline in both groups. The respiratory rates and levels of blood gases were similar in both groups. Hypoventilation and hypoxaemia were observed in both groups. The scores for anaesthetic effect, induction time, anaesthesia time and recovery times were similar in the two groups.
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Affiliation(s)
- J Y Lee
- Laboratory of Veterinary Surgery, College of Veterinary Medicine, Chungnam National University, 220 Kungdong, Yoosung-gu, Daejeon 305-764, Korea
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Santos LCP, Ludders JW, Erb HN, Basher KL, Kirch P, Gleed RD. Sedative and cardiorespiratory effects of dexmedetomidine and buprenorphine administered to cats via oral transmucosal or intramuscular routes. Vet Anaesth Analg 2010; 37:417-24. [DOI: 10.1111/j.1467-2995.2010.00555.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Lennquist A, Mårtensson Lindblad LGE, Hedberg D, Kristiansson E, Förlin L. Colour and melanophore function in rainbow trout after long term exposure to the new antifoulant medetomidine. CHEMOSPHERE 2010; 80:1050-1055. [PMID: 20538317 DOI: 10.1016/j.chemosphere.2010.05.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2009] [Revised: 05/04/2010] [Accepted: 05/10/2010] [Indexed: 05/29/2023]
Abstract
Medetomidine is a new antifouling agent, and its effects in non-target aquatic organisms have been investigated. Earlier short-term studies in fish have shown a skin lightening response to medetomidine, but effects after chronic exposure have not been studied. In fish, the dark pigment melanin is contained within specialized cells, melanophores. Medetomidine binds to the melanophore alpha2-adrenoceptor, which stimulates pigment aggregation resulting in the light appearance. In the present study, rainbow trout (Oncorhynchus mykiss) was long-term exposed to 0.5 and 5.0 nM of medetomidine via water for 54 d. The fish were then photographed for paleness quantification and the images were analyzed using ImageJ analysis software. Additionally, scales were removed and used for in vitro function studies of the melanophores, monitoring the response to melanophore stimulating hormone (MSH) and subsequent medetomidine addition. The number of melanophores was also investigated. As a result of the medetomidine exposure, fish from the 5 nM treatment were significantly paler than control fish and the melanophores from these fishes were also more aggregated. Melanophores from all the treatments were functional, responding to MSH by dispersion and to subsequent medetomidine by aggregation. However, the results indicate a difference in sensitivity among treatments. The number of melanophores in the scales did not change significantly after long term exposure to medetomidine. These results suggest that the observed paleness may be reversible, even after chronic exposure.
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Affiliation(s)
- Anna Lennquist
- Department of Zoology/Zoophysiology, University of Gothenburg, Sweden.
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Use of Thiafentanil–Medetomidine for the Induction of Anesthesia in Emus (Dromaius novaehollandiae) Within a Wild Animal Park. J Zoo Wildl Med 2010; 41:234-41. [DOI: 10.1638/2009-0143r1.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Lind U, Alm Rosenblad M, Hasselberg Frank L, Falkbring S, Brive L, Laurila JM, Pohjanoksa K, Vuorenpää A, Kukkonen JP, Gunnarsson L, Scheinin M, Mårtensson Lindblad LGE, Blomberg A. Octopamine Receptors from the Barnacle Balanus improvisus Are Activated by the α2-Adrenoceptor Agonist Medetomidine. Mol Pharmacol 2010; 78:237-48. [DOI: 10.1124/mol.110.063594] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
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Martin-Bouyer V, Schauvliege S, Duchateau L, Bosmans T, Gasthuys F, Polis I. Cardiovascular effects following epidural injection of romifidine in isoflurane-anaesthetized dogs. Vet Anaesth Analg 2010; 37:87-96. [DOI: 10.1111/j.1467-2995.2009.00489.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Pharmacological profile of intrathecal fadolmidine, a α2-adrenoceptor agonist, in rodent models. Naunyn Schmiedebergs Arch Pharmacol 2009; 380:539-50. [DOI: 10.1007/s00210-009-0460-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2009] [Accepted: 09/21/2009] [Indexed: 10/20/2022]
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Intravenous dexmedetomidine as an adjunct for labor analgesia and cesarean delivery anesthesia in a parturient with a tethered spinal cord. Int J Obstet Anesth 2009; 18:258-61. [PMID: 19188060 DOI: 10.1016/j.ijoa.2008.10.002] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2008] [Revised: 10/29/2008] [Accepted: 10/30/2008] [Indexed: 11/22/2022]
Abstract
For parturients desiring labor analgesia who have contraindications to neuraxial techniques, intravenous opioid-based patient-controlled analgesia (IVPCA) offers a reasonable alternative, although incomplete analgesia and maternal and neonatal respiratory depression can occur. Dexmedetomidine, a highly selective alpha(2) agonist with negligible placental transfer, may be a valuable adjunct to IVPCA by providing additional analgesia without the respiratory depression associated with increasing opioid usage. The successful use of a dexmedetomidine infusion as an adjunct to unsatisfactory fentanyl IVPCA is reported in a 31-year-old parturient with spina bifida occulta and a tethered spinal cord reaching L5-S1. Dexmedetomidine significantly improved the analgesic quality; increased sedation was observed, but the patient was easily rousable to verbal stimuli. No episodes of maternal hypotension or bradycardia, or fetal heart rate irregularities occurred. Cesarean delivery was required for prolonged first stage of labor and presumed chorioamnionitis; it was conducted under general anesthesia during which the dexmedetomidine infusion was continued. A healthy baby boy was delivered with normal Apgar scores and no discernible neurobehavioral or other deficits.
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Ishii H, Kohno T, Yamakura T, Ikoma M, Baba H. Action of dexmedetomidine on the substantia gelatinosa neurons of the rat spinal cord. Eur J Neurosci 2008; 27:3182-90. [PMID: 18554299 PMCID: PMC2658019 DOI: 10.1111/j.1460-9568.2008.06260.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Dexmedetomidine is a highly specific, potent and selective alpha(2)-adrenoceptor agonist. Although intrathecal and epidural administration of dexmedetomidine has been found to produce analgesia, whether this analgesia results from an effect on spinal cord substantia gelatinosa (SG) neurons remains unclear. Here, we investigated the effects of dexmedetomidine on postsynaptic transmission in SG neurons of rat spinal cord slices using the whole-cell patch-clamp technique. In 92% of the SG neurons examined (n = 84), bath-applied dexmedetomidine induced outward currents at -70 mV in a concentration-dependent manner, with the value of effective concentration producing a half-maximal response (0.62 microM). The outward currents induced by dexmedetomidine were suppressed by the alpha(2)-adrenoceptor antagonist yohimbine, but not by prazosin, an alpha(1)-, alpha(2B)- and alpha(2C)-adrenoceptor antagonist. Moreover, the dexmedetomidine-induced currents were partially suppressed by the alpha(2C)-adrenoceptor antagonist JP-1302, while simultaneous application of JP-1302 and the alpha(2A)-adrenoceptor antagonist BRL44408 abolished the current completely. The action of dexmedetomidine was mimicked by the alpha(2A)-adrenoceptor agonist oxymetazoline. Plots of the current-voltage relationship revealed a reversal potential at around -86 mV. Dexmedetomidine-induced currents were blocked by the addition of GDP-beta-S [guanosine-5'-O-(2-thiodiphosphate)] or Cs+ to the pipette solution. These findings suggest that dexmedetomidine hyperpolarizes the membrane potentials of SG neurons by G-protein-mediated activation of K+ channels through alpha(2A)- and alpha(2C)-adrenoceptors. This action of dexmedetomidine might contribute, at least in part, to its antinociceptive action in the spinal cord.
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Affiliation(s)
- Hideaki Ishii
- Division of Anesthesiology, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi, Niigata 951-8510, Japan
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Masuki S, Dinenno FA, Joyner MJ, Eisenach JH. Selective alpha2-adrenergic properties of dexmedetomidine over clonidine in the human forearm. J Appl Physiol (1985) 2005; 99:587-92. [PMID: 15802370 DOI: 10.1152/japplphysiol.00147.2005] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We tested the hypothesis that dexmedetomidine (Dex) has greater alpha(2)- vs. alpha(1) selectivity than clonidine and causes more alpha(2)-selective vasoconstriction in the human forearm. After local beta-adrenergic blockade with propranolol, forearm blood flow (plethysmography) responses to brachial artery administration of Dex, clonidine, and phenylephrine (alpha(1)-agonist) were determined in healthy young adults before and after alpha(2)-blockade with yohimbine (n = 10) or alpha(1)-blockade with prazosin (n = 9). Yohimbine had no effect on phenylephrine-mediated vasoconstriction but blunted Dex-mediated vasoconstriction (mean +/- SE: -41 +/- 5 vs. -11 +/- 2%; before vs. after yohimbine) more than clonidine-mediated vasoconstriction (-39 +/- 5 vs. -28 +/- 4%; before vs. after yohimbine) (P < 0.02). Prazosin blunted phenylephrine-mediated vasoconstriction (-39 +/- 4 vs. -8 +/- 2%; before vs. after prazosin) but had similar effects on both Dex- (-30 +/- 4 vs. -39 +/- 6%; before vs. after prazosin) and clonidine-mediated vasoconstriction (-29 +/- 3 vs. -41 +/- 7%; before vs. after prazosin) (P > 0.7). Both Dex and clonidine reduced deep forearm venous norepinephrine concentrations to a similar extent (-59 +/- 12 vs. -55 +/- 10 pg/ml; Dex vs. clonidine, P > 0.6); this effect was abolished by yohimbine and blunted by prazosin. These results suggest that Dex causes more alpha(2)-selective vasoconstriction in the forearm than clonidine. The similar vasoconstrictor responses to both drugs after prazosin might be explained by the presynaptic effects on norepinephrine release.
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Affiliation(s)
- Shizue Masuki
- Department of Anesthesiology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
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Bellas J, Hilvarsson A, Granmo A. Sublethal effects of a new antifouling candidate on lumpfish (Cyclopterus lumpus L.) and Atlantic cod (Gadus morhua L.) larvae. BIOFOULING 2005; 21:207-16. [PMID: 16371340 DOI: 10.1080/08927010500285236] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Sublethal effects of medetomidine, a new generation antifouling compound, on lumpfish (Cyclopterus lumpus L.) and cod (Gadus morhua L.) larvae were examined. The effects on respiration rate and on colour adaptation of newly hatched larvae were assessed after 24-96 h exposure. Exposure of lumpfish larvae to the experimental concentrations resulted in a significant decrease in respiration rate (Lowest Observed Effect Concentration (LOEC) = 5-10 nM) and in the percentage of dark larvae (LOEC = 4 nM). However, no effects on respiration rate of cod larvae were detected. In addition to lumpfish larvae being affected at low concentrations of medetomidine, a reversibility of the effects was observed when 96 h-exposed larvae were incubated in clean seawater for 24-48 h. Considerations relating to the future commercialisation of medetomidine for antifouling purposes are discussed.
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Affiliation(s)
- Juan Bellas
- Departamento de Ecoloxía e Bioloxía Animal, Universidade de Vigo, Ctra. Colexio Universitario s/n, Spain.
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38
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Kuo WC, Keegan RD. Comparative cardiovascular, analgesic, and sedative effects of medetomidine, medetomidine-hydromorphone, and medetomidine-butorphanol in dogs. Am J Vet Res 2004; 65:931-7. [PMID: 15281651 DOI: 10.2460/ajvr.2004.65.931] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To compare sedative, analgesic, and cardiopulmonary effects after IV administration of medetomidine (20 microg/kg), medetomidine-hydromorphone (20 microg of medetomidine/kg and 0.1 mg of hydromorphone/kg), and medetomidine-butorphanol (20 microg of medetomidine/kg and 0.2 mg of butorphanol tartrate/kg) in dogs. ANIMALS 6 dogs healthy mixed-breed dogs. PROCEDURE Instruments were surgically inserted, and heart rate (HR), respiratory rate (RR), systolic arterial pressure (SAP), mean arterial pressure (MAP), diastolic arterial pressure (DAP), mean pulmonary arterial pressure (MPAP), pulmonary capillary wedge pressure (PCWP), central venous pressure (CVP), core body temperature, and cardiac output (CO) were measured 0, 5, 10, 15, 30, 45, and 60 minutes after injection. Cardiac index (CI), stroke volume (SV), stroke index (SI), systemic vascular resistance (SVR), and pulmonary vascular resistance (PVR) were calculated. Arterial samples for blood gas analysis were collected 0, 15, and 45 minutes after injection. Intensity of analgesia, degree of sedation, and degree of muscle relaxation were evaluated at aforementioned time points and 75, 90, 120, 150, 180, and 210 minutes after injection. RESULTS Administration of medetomidine, medetomidine-hydromorphone, and medetomidine-butorphanol was associated with increases in SAP, MAP, DAP, MPAP, PCWP, CVP, SVR, PVR, core body temperature, and PaCO2 and decreases in HR, CO, CI, SV, SI, RR, pH, and PaO2. Clinically important differences were not detected among treatments. Medetomidine-hydromorphone and medetomidine-butorphanol provided a longer duration of sedation and better quality of analgesia, compared with medetomidine alone. CONCLUSIONS AND CLINICAL RELEVANCE Medetomidine-hydromorphone or medetomidine-butorphanol is associated with improved analgesia and sedation but has cardiopulmonary effects comparable to those for medetomidine alone.
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Affiliation(s)
- Wei-Chen Kuo
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, USA
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Muir WW, Gadawski JE. Cardiovascular effects of a high dose of romifidine in propofol-anesthetized cats. Am J Vet Res 2002; 63:1241-6. [PMID: 12224853 DOI: 10.2460/ajvr.2002.63.1241] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine the hemodynamic effects of IM administration of romifidine hydrochloride in propofol-anesthetized cats. ANIMALS 15 adult domestic shorthair cats. PROCEDURE Cats were randomly assigned to receive romifidine (0, 400, or 2,000 microg/kg, IM). Cats were anesthetized with propofol and mechanically ventilated with oxygen. The right jugular vein, left carotid artery, and right femoral artery and vein were surgically isolated and catheterized. Heart rate; duration of the PR, QRS, and QT intervals; mean pulmonary artery pressure; mean right atrial pressure; systolic, diastolic, and mean arterial pressures; left ventricular systolic pressure; left ventricular end-diastolic pressure; and cardiac output were monitored. Systemic vascular resistance, rate of change of left ventricular pressure, and rate pressure product were calculated. Arterial and venous blood samples were collected anaerobically for determination of pH and blood gas tensions (Po2 and Pco2). RESULTS Administration of romifidine at 400 and 2,000 microg/kg, IM, decreased heart rate, cardiac output, rate of change of left ventricular pressure, rate pressure product, and pH. Arterial and pulmonary artery pressures, left ventricular pressure, left ventricular end-diastolic pressure, and right atrial pressure increased and then gradually returned to baseline values. Arterial blood gas values did not change, whereas venous Pco2 increased and venous Po2 decreased. Significant differences between low and high dosages were rare, suggesting that the dosages investigated produced maximal hemodynamic effects. CONCLUSIONS AND CLINICAL RELEVANCE Romifidine produces cardiovascular effects that are similar to those of other alpha2-agonists. High dosages of romifidine should be used with caution in cats with cardiovascular compromise.
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Affiliation(s)
- William W Muir
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus 43210-1089, USA
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Lamont LA, Bulmer BJ, Grimm KA, Tranquilli WJ, Sisson DD. Cardiopulmonary evaluation of the use of medetomidine hydrochloride in cats. Am J Vet Res 2001; 62:1745-9. [PMID: 11703018 DOI: 10.2460/ajvr.2001.62.1745] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate the cardiovascular effects of the alpha2-adrenergic receptor agonist medetomidine hydrochloride in clinically normal cats. ANIMALS 7 clinically normal cats. PROCEDURE Cats were anesthetized with isoflurane, and thermodilution catheters were placed for measurement of central venous, pulmonary, and pulmonary capillary wedge pressures and for determination of cardiac output. The dorsal pedal artery was catheterized for measurement of arterial blood pressures and blood gas tensions. Baseline variables were recorded, and medetomidine (20 microg/kg of body weight, IM) was administered. Hemodynamic measurements were repeated 15 and 30 minutes after medetomidine administration. RESULTS Heart rate, cardiac index, stroke index, rate-pressure product, and right and left ventricular stroke work index significantly decreased from baseline after medetomidine administration, whereas systemic vascular resistance and central venous pressure increased. However, systolic, mean, and diastolic arterial pressures as well as arterial pH, and oxygen and carbon dioxide tensions were not significantly different from baseline values. CONCLUSIONS AND CLINICAL RELEVANCE When administered alone to clinically normal cats, medetomidine (20 microg/kg, IM) induced a significant decrease in cardiac output, stroke volume, and heart rate. Arterial blood pressures did not increase, which may reflect a predominant central alpha2-adrenergic effect over peripheral vascular effects.
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Affiliation(s)
- L A Lamont
- Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Urbana 61801, USA
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Itamoto K, Taura Y, Wada N, Taga A, Takuma T, Matsumura H, Miyara T. Effect of medetomidine on electroencephalography and use of a quantitative electroencephalograph for evaluating sedation levels in dogs. JOURNAL OF VETERINARY MEDICINE. A, PHYSIOLOGY, PATHOLOGY, CLINICAL MEDICINE 2001; 48:525-35. [PMID: 11765809 DOI: 10.1046/j.1439-0442.2001.00381.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
This study was designed to characterize the effect of medetomidine (Med) on canine electroencephalography (EEG), to evaluate the use of quantitative EEG for assessing sedation levels and to explore the correlation between the serum concentration of Med and the quantitative EEG. Four groups of dogs were given Med at doses of 20, 40, 80 and 160 microg/kg (Med-20, Med-40, Med-80 and Med-160 groups). Following Med administration, there was synchrony between each unipolar EEG lead. On EEG power spectrum analysis of the bipolar leads, all groups showed a significant depression of the 14-30 Hz components. The power of the 1-3 Hz component in the Med-80 and Med-160 groups was significantly increased, although there were few changes in the other groups. Similar results were obtained from raw data analysis. As a result of quantitative EEG analysis, spectrum edge frequency 90 analysis (SEP90) showed that the frequency was significantly reduced in all groups after Med administration. A dose-response effect was observed in all groups except for the Med-160 group. Both of these EEG analyses were significantly correlated with the serum concentration of Med. However, the result of the SPF90 analysis sugested a stronger correlation than that for median edge frequency analysis. In conclusion, care must be taken in veterinary clinical diagnoses when Med is used during EEG recording, as Med may cause increased activity in the low frequency band and a decrease in high frequency band activity. In addition, quantitative EEG analysis may be useful in assessing the depth of sedation and in further studies on Med administration.
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Affiliation(s)
- K Itamoto
- The United Graduate School of Veterinary Science, Yamaguchi University, Japan
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Mpanduji DG, Bittegeko SB, Batamuzi EK, Mgasa MN, Shami CL. Comparison of the effects of atipamezole and tolazoline on analgesia, cardiopulmonary and rectal temperature changes induced by lumbosacral epidural injection of medetomidine in goats. Small Rumin Res 2001; 40:117-122. [PMID: 11295393 DOI: 10.1016/s0921-4488(00)00216-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The present study was carried out in order to compare the reversing effects of alpha(2)-adrenergic receptor antagonists, atipamezole and tolazoline on analgesia, cardiopulmonary depression and rectal temperature changes induced by epidural administration of medetomidine in goats. Eight clinically healthy, small East African goats of both sexes weighing between 12 and 17kg (mean 14.4+/-1.8kg) were used in this study. The animals were randomly divided into two groups of four animals. The first group was given 20µg/kg medetomidine followed by intravenous (IV) administration of 80µg/kg atipamezole, 30min after the initial injection. The second group was given same treatment for medetomidine as group one but followed by IV administration of 2.2mg/kg tolazoline, 30min after the initial injection. In both treatment groups, medetomidine was administered epidurally through the lumbosacral interspace. Analgesia of the flank and perineum was evaluated at every 10min intervals up to 60min. The cardiopulmonary and rectal temperature values were monitored and recorded at every 5min interval up to 60min. In both groups, lumbosacral epidural injection of medetomidine induced generalised analgesia, variable cardiopulmonary depression effects and non-significant changes on rectal temperature. These changes developed as early as 5min and continued until alpha(2)/alpha(1) antagonists were administered. Intravenous administration of alpha-adrenergic receptor antagonists; atipamezole and tolazoline reversed analgesia, cardiopulmonary and rectal temperature changes induced by lumbosacral epidural injection of medetomidine in goats. However, atipamezole appeared to be superior (P<0.05) to tolazoline. From this study, it was concluded that IV administration of 80µg/kg atipamezole was better than 2.2mg/kg tolazoline in reversing analgesia and cardiopulmonary depression effects induced by lumbosacral epidural injection of medetomidine in goats. This indicates the superiority of atipamezole to tolazoline as an antidote for medetomidine induced effects in goats.
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Affiliation(s)
- D G. Mpanduji
- Department of Veterinary Surgery and Theriogenology, Sokoine University of Agriculture, P.O. Box 3020, Morogoro, Tanzania
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Mustanoja SM, Hätönen T, Alila-Johansson A, Laakso M. Evidence for central alpha(2)-adrenergic modulation of rat pineal melatonin synthesis. Brain Res 2000; 887:174-7. [PMID: 11134601 DOI: 10.1016/s0006-8993(00)02975-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
This study was performed to distinguish central and peripheral alpha(2)-adrenoceptors in the inhibition of rat pineal melatonin synthesis. The rats received lipo- or hydrophilic alpha(2)-adrenoceptor ligand injections at middark; after 1 or 2 h the pineal melatonin contents were measured. The lipophilic agonist medetomidine (100 microg/kg s.c.) suppressed the melatonin contents significantly, while the hydrophilic agonists ST-91 and p-aminoclonidine (10 or 100 microg/kg i.v.) did not. The suppression by medetomidine was counteracted by the lipophilic antagonist yohimbine (0.3-3.0 mg/kg i.p.) but not by the hydrophilic antagonist L-659,066 (1-10 mg/kg i.v.). In conclusion, the suppression of nocturnal melatonin synthesis by alpha(2)-adrenoceptor agonists is mainly of central origin.
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Affiliation(s)
- S M Mustanoja
- Department of Physiology, Institute of Biomedicine, University of Helsinki, Helsinki, Finland.
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Vogelnest L, Mueller R, Dart C. The suitability of medetomidine sedation for intradermal skin testing in dogs. Vet Dermatol 2000. [DOI: 10.1046/j.1365-3164.2000.00205.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Fernández MM, Calama E, Morán A, Martín ML, San Román L. Characterization of mechanisms involved in presynaptic inhibition of sympathetic pressor effects induced by some 5-HT1 receptor antagonists. ACTA ACUST UNITED AC 2000; 20:313-23. [PMID: 11350497 DOI: 10.1046/j.1365-2680.2000.00197.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
1. In a previous study, we showed that the presynaptic inhibitory action of 5-hydroxytryptamine receptor agonists on sympathetic pressor effects obtained in the pithed rats were mainly mediated by activation of 5-HT1A and 5-HT1D receptor subtypes. At the time, we observed that some 5-HT1 receptors antagonists - WAY 100,635 and NAN-190 (both 5-HT1A receptor antagonists), methiothepin (a 5-HT1,2,5,6,7 receptor antagonist) and spiperone (a 5-HT1,2 receptor antagonist) - reduced per se the pressor effects obtained by electrical stimulation. The aim of the present work was to investigate the mechanism participating in this inhibitory effect. 2. The inhibition induced by WAY 100,635 (1000 microg kg-1, i.v.) was blocked after i.v. treatment with idazoxan, an alpha2-adrenoceptor antagonist (300 and 1000 microg kg-1) and was not modified after i.v. treatment with propranolol, a beta-adrenoceptor antagonist (1000 microg kg-1) and sulpiride, a D2 receptor antagonist (1000 microg kg-1). The inhibition induced by spiperone (500 microg kg-1 i.v.) was significantly blocked by sulpiride (1000 microg kg-1) and was not modified by idazoxan or propranolol. 3. Sulpiride (1000 microg kg-1) partially blocked the inhibition induced by methiothepin (50 microg kg-1 i.v.). Only pretreatment with idazoxan (300 microg kg-1) modified the inhibition induced by NAN-190 (100 microg kg-1 i.v.), such inhibition increasing after intravenous administration of idazoxan. 4. All the antagonists used in our experiments failed to inhibit the pressor responses elicited by i.v. noradrenaline administration. 5. The above results suggest that the inhibitory effects of these 5-HT1 receptor antagonists are presynaptic in nature, but not related to the blockade of 5-HT1 receptors subtypes. The simultaneous activation or inhibition of other receptor systems could explain the inhibition produced by each 5-HT1 receptor antagonist studied.
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Affiliation(s)
- M M Fernández
- Laboratorio de Farmacognosia y Farmacología, Departamento de Fisiología y Farmacología, Facultad de Farmacia, Universidad de Salamanca, Salamanca, Spain
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SANDMEIER PETER. Evaluation of Medetomidine for Short-Term Immobilization of Domestic Pigeons (Columba livia) and Amazon Parrots (Amazonaspecies). J Avian Med Surg 2000. [DOI: 10.1647/1082-6742(2000)014[0008:eomfst]2.0.co;2] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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47
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Mpanduji DG, Bittegeko SB, Mgasa MN, Batamuzi EK. Analgesic, behavioural and cardiopulmonary effects of epidurally injected medetomidine (Domitor) in goats. JOURNAL OF VETERINARY MEDICINE. A, PHYSIOLOGY, PATHOLOGY, CLINICAL MEDICINE 2000; 47:65-72. [PMID: 10803105 DOI: 10.1046/j.1439-0442.2000.00254.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
This study was carried out in order to evaluate the analgesic, sedative, immobilizing and cardiopulmonary effects of medetomidine in goats after lumbosacral epidural injection of three (10, 20 and 30 micrograms/kg body weight) doses. The volume of the injection for all three medetomidine doses was 5 ml in sterile water. Seventeen clinically healthy, Small East African goats of either sex and weighing between 12 and 22 kg (mean +/- SD; 14.8 +/- 2.5 kg body weight) were used. The animals were randomly assigned to two groups. Seven goats were used for evaluating analgesic, behavioural and cardiopulmonary effects while 10 were used for experimental surgery. The cardiopulmonary values and rectal temperature were determined and recorded at time 0 (preinjection) and at 5, 10, 15, 20 and 30 min, and thereafter at 15-min intervals up to 180 min after injection. Analgesia of the flank and perineum was determined at time 0 (preinjection) and at 5, 10, 15, 30, 60, 120 and 180 min using a scoring system. The spread of analgesia to the thorax, neck, forelimbs and head was also determined and recorded. The onset and duration of lateral recumbency was noted and recorded. Medetomidine at the given doses induced variable cardiopulmonary depression, which was not detrimental to the animals. All three doses (10, 20 and 30 micrograms/kg) of medetomidine induced adequate analgesia of the flank and perineum. Analgesia extended to the thorax, forelimbs, neck and head. The duration of lateral recumbency was 136 and 166 min for the 20 and 30 micrograms/kg medetomidine doses, respectively. The duration of lateral recumbency was not determined for the animal given 10 micrograms/kg medetomidine. Signs of sedation (lowering of the head, drooping of the lower lip, partial to complete closure of the eyes and salivation) were noted after administration of all three doses. It can be concluded from this study that all three doses induced adequate analgesia of the flank and perineum. Surgical analgesia of the flank of goats was achieved after lumbosacral epidural administration of 20 micrograms medetomidine/kg, diluted in 5 ml of sterile water. Surgery was not performed with the other doses (10 and 30 micrograms/kg) of medetomidine.
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Affiliation(s)
- D G Mpanduji
- Department of Veterinary Surgery and Theriogenology, Sokoine University of Agriculture, Chuo Kikuu, Morogoro Tanzania
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48
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Ansah OB, Raekallio M, Vainio O. Correlation between serum concentrations following continuous intravenous infusion of dexmedetomidine or medetomidine in cats and their sedative and analgesic effects. J Vet Pharmacol Ther 2000; 23:1-8. [PMID: 10747237 DOI: 10.1046/j.1365-2885.2000.00240.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Dexmedetomidine (DEX) may have some therapeutic advantages over the racemate medetomidine (MED). Here we have examined how serum concentrations of DEX correlate with some of its anaesthetic effects. Cats (n = 6) were administered with a continuous stepwise intravenous (i.v.) infusion of DEX or MED on different occasions in a cross-over design. Maintenance infusion rates (mg/kg/min) used were: DEX = 0.25 (MED = 0.50); DEX = 1 (MED = 2) and DEX = 4 (MED = 8) for infusion steps 1, 2 and 3, respectively. Each maintenance infusion lasted at least 50 min and was preceded with a loading dose. There was no significant difference between serum DEX and 0.5 serum MED concentrations at any dose level nor was there a significant difference between serum DEX and the (entire) serum MED concentrations. There was no significant difference between DEX and MED for sedation, analgesia, muscular relaxation and heart and respiratory rates. For both DEX and MED, serum drug concentration and analgesia were dose-dependent and sedation increased until the end of infusion step 2 (dose level 2) and decreased at the end of step 3 (dose level 3). Muscular relaxation was not dose-dependent. We conclude that increasing the blood concentration of DEX or MED beyond a certain level decreases the level of sedation instead of increasing it even though analgesia increases. The rate at which DEX and MED are metabolized in cats may not be the same.
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Affiliation(s)
- O B Ansah
- Faculty of Veterinary Medicine, Department of Clinical Sciences, Hämeentie 57 FIN-00014 University of Helsinki, Finland
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Tarvainen T, Svarfvar B, Akerman S, Savolainen J, Karhu M, Paronen P, Järvinen K. Drug release from a porous ion-exchange membrane in vitro. Biomaterials 1999; 20:2177-83. [PMID: 10555086 DOI: 10.1016/s0142-9612(99)00122-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The effect of environmental ionic strength on the rate of drug release from a cation exchange membrane was evaluated. Cationic propranolol-HCl, timolol, sotalol-HCl, atenolol and dexmedetomidine-HCl and neutral diazepam were adsorbed onto a porous poly(vinylidene fluoride) (PVDF) membrane that was grafted with bioadhesive poly(acrylic acid) chains (PAA-PVDF). Despite its porosity, the PAA-PVDF membrane acted as a cation exchange membrane. The release of adsorbed drug from the PAA-PVDF membrane was investigated by using a USP rotating basket apparatus. Adsorption of cationic drugs onto the PAA-PVDF membrane tended to increase with increasing lipophilicity of the drug. A decrease in the ionic strength of the adsorption medium increased the amount of the cationic drugs adsorbed onto the membrane, but had no effect on diazepam adsorption. The release of cationic drugs from the PAA-PVDF membrane was greatly affected by the ionic strength of both the adsorption medium and the dissolution medium, while ionic strengths did not affect diazepam release. Our results suggest that the ionic strength of both the adsorption and dissolution media substantially affects the release rate of a drug that has been adsorbed onto the ion exchange membrane, primarily via electrostatic interactions, while ionic strength has no effect on the release of a drug which has been adsorbed onto the membrane via non-electrostatic forces.
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Affiliation(s)
- T Tarvainen
- Department of Pharmaceutics, University of Kuopio, Finland.
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Bryant CE, Thompson J, Clarke KW. Characterisation of the cardiovascular pharmacology of medetomidine in the horse and sheep. Res Vet Sci 1998; 65:149-54. [PMID: 9839894 DOI: 10.1016/s0034-5288(98)90167-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Medetomidine was administered to sheep and horses at a dose rate of 5 microg kg(-1) (i.v.). Heart rate and blood pressure were recorded. Medetomidine induced bradycardia and a biphasic blood pressure response consisting of a transient hypertension followed by hypotension. Administration of prazosin (an alpha1 adrenoceptor antagonist; 100 microg kg(-1), i.v.) had no effect on the cardiovascular response to medetomidine (5 microg kg(-1), i.v.), but inhibited the cardiovascular response of methoxamine (an alpha1 adrenoceptor agonist; 75 microg kg(-1), i.v.). L-659,066 (an alpha2 adrenoceptor antagonist which does not cross the blood brain barrier; 264 microg kg(-1), i.v.) attenuated the medetomidine induced bradycardia, but had no effect on the cardiovascular response to methoxamine. L659,066 also reduced the medetomidine induced hypertension in sheep, but had less effect on the horse. It is concluded that both alpha1 and alpha2 adrenoceptors are important in the control of cardiovascular function in horses and sheep. Medetomidine appears to act on alpha2 adrenoceptors alone in the sheep. The cardiovascular effects of medetomidine in the horse are complex and may be influenced by central alpha2 adrenoceptor regulation or effects on other receptor subtypes as well as direct stimulation of peripheral alpha2 adrenoceptors.
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Affiliation(s)
- C E Bryant
- Department of Farm Animal and Equine Medicine and Surgery, The Royal Veterinary College, The University of London, Hatfield, Herts
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