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Abstract
With the increasing frequency of rabbits as veterinary patients, the expectation for high-quality, intensive veterinary care, and resultantly an understanding of anesthesia has been increasing. Sedation and general anesthesia are commonly required for many routine and emergency procedures in rabbits, and this results in the need for a strong awareness of anesthetic principles, knowledge of limitations of anesthesia, and maintenance of high standards of anesthesia.
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van den Berg JP, Eleveld DJ, De Smet T, van den Heerik AVM, van Amsterdam K, Lichtenbelt BJ, Scheeren TWL, Absalom AR, Struys MMRF. Influence of Bayesian optimization on the performance of propofol target-controlled infusion. Br J Anaesth 2019; 119:918-927. [PMID: 29028925 DOI: 10.1093/bja/aex243] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/02/2017] [Indexed: 11/12/2022] Open
Abstract
Background Target controlled infusion (TCI) systems use population-based pharmacokinetic (PK) models that do not take into account inter-individual residual variation. This study compares the bias and inaccuracy of a population-based vs a personalized TCI propofol titration using Bayesian adaptation. Haemodynamic and hypnotic stability, and the prediction probability of alternative PK models, was studied. Methods A double-blinded, prospective randomized controlled trial of 120 subjects undergoing cardiac surgery was conducted. Blood samples were obtained at 10, 35, 50, 65, 75 and 120 min and analysed using a point-of-care propofol blood analyser. Bayesian adaptation of the PK model was applied at 60 min in the intervention group. Median (Absolute) Performance Error (Md(A)PE) was used to evaluate the difference between bias and inaccuracy of the models. Haemodynamic (mean arterial pressure [MAP], heart rate) and hypnotic (bispectral index [BIS]) stability was studied. The predictive performance of four alternative propofol PK models was studied. Results MdPE and MdAPE did not differ between groups during the pre-adjustment period (control group: 6.3% and 16%; intervention group: 5.4% and 18%). MdPE differed in the post-adjustment period (12% vs. -0.3%), but MdAPE did not (18% vs. 15%). No difference in heart rate, MAP or BIS was found. Compared with the other models, the Eleveld propofol PK model (patients) showed the best prediction performance. Conclusions When an accurate population-based PK model was used for propofol TCI, Bayesian adaption of the model improved bias but not precision. Clinical trial registration Dutch Trial Registry NTR4518.
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Affiliation(s)
- J P van den Berg
- Department of Anesthesiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - D J Eleveld
- Department of Anesthesiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | | | - A V M van den Heerik
- Department of Anesthesiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - K van Amsterdam
- Department of Anesthesiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - B J Lichtenbelt
- Department of Anesthesiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - T W L Scheeren
- Department of Anesthesiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - A R Absalom
- Department of Anesthesiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - M M R F Struys
- Department of Anesthesiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.,Department of Anaesthesia and Peri-Operative Medicine, Ghent University, Ghent, Belgium
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Campos S, Monteiro J, Valenzuela B, Gonçalinho H, de Pinho PG, Fresco P, Félix L, Antunes L. Evidence of Different Propofol Pharmacokinetics under Short and Prolonged Infusion Times in Rabbits. Basic Clin Pharmacol Toxicol 2015; 118:421-31. [PMID: 26551921 DOI: 10.1111/bcpt.12521] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 10/26/2015] [Indexed: 01/21/2023]
Abstract
Propofol is an anaesthetic widely used in both human beings and animals. However, the characterization of propofol pharmacokinetics (PK) is not well understood when long-term infusions are used. The main objective of this study was to explore the PK behaviour of propofol in a rabbit model during short and prolonged propofol infusions and to develop an internally validated PK model, for propofol dose individualization in the rabbit for future use. Population 1 (P1) was constituted by seven New Zealand rabbits and was used to characterize the PK profile of propofol at short infusions. Animals were anaesthetized with a bolus of 20 mg/kg, followed by an infusion rate of 50 mg/kg/hr of propofol at 1%, which was then maintained for 30 min. A second rabbit population (P2, n = 7) was sedated according to reflexes responses and Index of Consciousness values, for 20 consecutive hours using propofol 2% aiming at characterizing propofol behaviour at long-term infusions. Clinical data and blood samples were collected at specific time-points in both populations. Propofol plasma concentrations were determined by gas chromatography/ion trap mass spectrometry. The NONMEM VII software was used to evaluate the relationships between dose and plasma concentrations. A linear two-compartment model with different central compartment volume and plasma clearance (separately modelled in the two populations) was the one that best described propofol concentrations. The time course of propofol plasma concentrations was well characterized by the PK model developed, which simultaneously accounts for propofol short- and long-term infusions and can be used to optimize future PK studies in rabbits.
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Affiliation(s)
- Sónia Campos
- Centre for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB) and Veterinary Sciences Department of the University of Trás-os-Montes and Alto Douro (UTAD), Portugal.,Laboratory Animal Science Institute of Molecular and Cell Biology (IBMC), Porto University, Porto, Portugal.,UCIBIO@REQUIMTE, Laboratory of Toxicology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, Porto, Portugal
| | - Joaquim Monteiro
- IINFACTS - Instituto de Investigação e Formação Avançada em Ciências e Tecnologia da Saúde, CESPU, Paredes, Portugal.,Faculty of Medicine, University of Porto, Porto, Portugal
| | - Belén Valenzuela
- Platform of Oncology, Hospital Quirón Torrevieja, Torrevieja, Alicante, Spain.,Cathedra of Multidisciplinary Oncology - UCAM, Catholic University of San Antonio, Murcia, Spain
| | - Helena Gonçalinho
- Laboratory of Pharmacology, Department of Drug Sciences, Faculty of Pharmacy, University of Porto, Porto, Portugal
| | - Paula Guedes de Pinho
- UCIBIO@REQUIMTE, Laboratory of Toxicology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, Porto, Portugal
| | - Paula Fresco
- Laboratory of Pharmacology, Department of Drug Sciences, Faculty of Pharmacy, University of Porto, Porto, Portugal
| | - Luis Félix
- Laboratory Animal Science Institute of Molecular and Cell Biology (IBMC), Porto University, Porto, Portugal
| | - Luís Antunes
- Centre for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB) and Veterinary Sciences Department of the University of Trás-os-Montes and Alto Douro (UTAD), Portugal.,Laboratory Animal Science Institute of Molecular and Cell Biology (IBMC), Porto University, Porto, Portugal
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Kervezee L, Stevens J, Birkhoff W, Kamerling IMC, de Boer T, Dröge M, Meijer JH, Burggraaf J. Identifying 24 h variation in the pharmacokinetics of levofloxacin: a population pharmacokinetic approach. Br J Clin Pharmacol 2015; 81:256-68. [PMID: 26852745 DOI: 10.1111/bcp.12783] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 09/08/2015] [Accepted: 09/11/2015] [Indexed: 01/22/2023] Open
Abstract
AIM The objective of this study was to investigate whether the pharmacokinetics of orally administered levofloxacin show 24 h variation. Levofloxacin was used as a model compound for solubility and permeability independent absorption and passive renal elimination. METHODS In this single centre, crossover, open label study, 12 healthy subjects received an oral dose of 1000 mg levofloxacin at six different time points equally divided over the 24 h period. Population pharmacokinetic modelling was used to identify potential 24 h variation in the pharmacokinetic parameters of this drug. RESULTS The pharmacokinetics of levofloxacin could be described by a one compartment model with first order clearance and a transit compartment to describe drug absorption. The fit of the model was significantly improved when the absorption rate constant was described as a cosine function with a fixed period of 24 h, a relative amplitude of 47% and a peak around 08.00 h in the morning. Despite this variation in absorption rate constant, simulations of a once daily dosing regimen showed that tmax , Cmax and the area under the curve at steady-state were not affected by the time of drug administration. CONCLUSION The finding that the absorption rate constant showed considerable 24 h variation may be relevant for drugs with similar physicochemical properties as levofloxacin that have a narrower therapeutic index. Levofloxacin, however, can be dosed without taking into account the time of day, at least in terms of its pharmacokinetics.
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Affiliation(s)
- Laura Kervezee
- Laboratory for Neurophysiology, Department of Molecular Cell Biology, Leiden University Medical Center, Leiden.,Centre for Human Drug Research, Leiden
| | | | | | | | | | | | - Johanna H Meijer
- Laboratory for Neurophysiology, Department of Molecular Cell Biology, Leiden University Medical Center, Leiden
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The influence of the time of day on midazolam pharmacokinetics and pharmacodynamics in rabbits. Pharmacol Rep 2014; 66:143-52. [PMID: 24905320 DOI: 10.1016/j.pharep.2013.06.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2012] [Revised: 06/05/2013] [Accepted: 06/20/2013] [Indexed: 11/17/2022]
Abstract
BACKGROUND This study evaluates the time-of-day effect on midazolam and 1-OH midazolam pharmacokinetics, and on the sedative pharmacodynamic response in rabbits. Also, circadian fluctuations in rabbits' vital signs, such as the blood pressure, heart rate and body temperature were examined. The water intake was measured in order to confirm the presence of the animals' diurnal activity. The secondary aim involved the comparison of two methods of data analysis: a noncompartmental and a population modeling approach. METHODS Twelve rabbits were sedated with intravenous midazolam 0.35 mg/kg at four local times: 09.00, 14.00, 18.00 and 22.00 h. Each rabbit served as its own control by being given a single infusion at the four different times of the day on four separate occasions. The values of the monitored physiological parameters were recorded during the experiment and arterial blood samples were collected for midazolam assay. The pedal withdrawal reflex was used as the measurement of the sedation response. Two and one compartmental models were successfully used to describe midazolam and 1-OH midazolam pharmacokinetics. The categorical pharmacodynamic data were described with a logistic model. RESULTS AND CONCLUSIONS We did not find any time-of-day effects for the pharmacokinetic and pharmacodynamics parameters of midazolam. For 1-OH midazolam, statistically significant time-of-day differences in the apparent volume of distribution and clearance were noticed. They corresponded well with the rabbits' water intake. The noncompartmental and model-based parameters were essentially similar. However, more information can be obtained from the population model and this method should be preferred in chronopharmacokinetic and chronopharmacodynamic studies.
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Bienert A, Bartkowska-Sniatkowska A, Wiczling P, Rosada-Kurasińska J, Grześkowiak M, Zaba C, Teżyk A, Sokołowska A, Kaliszan R, Grześkowiak E. Assessing circadian rhythms during prolonged midazolam infusion in the pediatric intensive care unit (PICU) children. Pharmacol Rep 2013; 65:107-21. [PMID: 23563029 DOI: 10.1016/s1734-1140(13)70969-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Revised: 08/14/2012] [Indexed: 01/30/2023]
Abstract
BACKGROUND This study evaluates possible circadian rhythms during prolonged midazolam infusion in 27 pediatric intensive care unit (PICU) children under mechanical ventilation. METHODS Blood samples for midazolam and 1-OH-midazolam assay were collected throughout the infusion at different times of the day. The blood pressure, heart rate and body temperature were recorded every hour for the rhythms analysis. Population nonlinear mixed-effect modeling with NONMEM was used for data analysis. RESULTS A two-compartment model for midazolam pharmacokinetics and a one-compartment model for midazolam metabolite adequately described the data. The 24 h profiles of all monitored physiological parameters were greatly disturbed/abolished in comparison with the well-known 24 h rhythmic patterns in healthy subjects. There was no significant circadian rhythm detected with respect to midazolam pharmacokinetics, its active metabolite pharmacokinetics and all monitored parameters. CONCLUSIONS We concluded that the light-dark cycle did not influence midazolam pharmacokinetics in intensive care units children. Also, endogenous rhythms in critically ill and sedated children are severely disturbed and desynchronized. Our results confirmed that it is necessary to adjust the dose of midazolam to the patient's body weight. The low value of midazolam clearances observed in our study was probably caused by mechanical ventilation, which was shown to decrease the cardiac output.
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Affiliation(s)
- Agnieszka Bienert
- Department of Clinical Pharmacy and Biopharmacy, Karol Marcinkowski University of Medical Sciences, Marii Magdaleny 14, PL 61-861 Poznań, Poland.
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Bienert A, Wiczling P, Grześkowiak E, Cywiński JB, Kusza K. Potential pitfalls of propofol target controlled infusion delivery related to its pharmacokinetics and pharmacodynamics. Pharmacol Rep 2012; 64:782-95. [DOI: 10.1016/s1734-1140(12)70874-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Revised: 04/05/2012] [Indexed: 10/25/2022]
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