Propofol is a short-acting intravenous anesthetic agent commonly used in veterinary medicine, including equine practice, for the induction and maintenance of anesthesia. It facilitates smooth and rapid sedation and recovery, making it a preferred choice for various surgical and diagnostic procedures in horses. Propofol acts primarily on the central nervous system by enhancing the inhibitory neurotransmitter gamma-aminobutyric acid (GABA), leading to sedation and hypnosis. Its pharmacokinetics and pharmacodynamics in horses, including metabolism, clearance, and effects on cardiovascular and respiratory systems, are subjects of ongoing research. This page compiles peer-reviewed research studies and scholarly articles that explore the use, administration protocols, and physiological effects of propofol in equine anesthesia.
Kerr CL, Keating SCJ, Arroyo LG, Viel L.Neonatal foals may require prolonged sedation to permit ventilatory support in the first few days of life. The objective of this study was to evaluate and compare the cardiopulmonary effects and clinical recovery characteristics of 2 sedative/analgesia protocols in healthy foals receiving assisted ventilation. Foals were randomized to receive dexmedetomidine, butorphanol, and propofol (DBP) or midazolam, butorphanol, and propofol (MBP) during a 24-hour period. Infusion rates of dexmedetomidine, midazolam, and propofol were adjusted and propofol boluses administered according to set protocols t...
Ellis JS, Mama KR, Rao S, Sadler RA, Marinkovich M, Clancy MM, Howard LL, Lamberski N, Kinney ME.Przewalski's horses () are an endangered equid species. Anesthesia administered by remote delivery is often needed to provide medical care. Behavioral and physiologic parameters were prospectively compared in 14 horses (8 females and 6 males, 3-18 yr) after a single-dart or staged two-dart anesthesia induction protocol with intramuscular medetomidine (0.06 mg/kg), butorphanol (0.05 mg/kg), thiafentanil (0.02 mg/kg), and ketamine (1 mg/kg). Seven horses were randomly assigned to receive all drugs in a single dart, and the other seven to receive medetomidine and butorphanol 10 min prior to thiaf...
Tokushige H, Araki M, Kusano K, Arima D, Ito H, Yamazaki Y, Urayama S, Kambayashi Y, Tateno O, Ohta M.This study compares clinical characteristics between induction with thiopental/guaifenesin and propofol/ketamine in Thoroughbred racehorses anesthetized with sevoflurane and medetomidine. Clinical records of 214 horses that underwent arthroscopic surgery between 2015 and 2016 were retrospectively retrieved. Horses were premedicated with medetomidine and midazolam to sedate at the adequate level for smooth induction, and then induced with either thiopental (4.0 mg/kg) and guaifenesin (100 mg/kg) in Group TG (n=91) or propofol (1.0 mg/kg) and ketamine (1.0 mg/kg) in Group PK (n=123). Anesthesia ...
Tokushige H, Okano A, Arima D, Ito H, Kambayashi Y, Minamijima Y, Ohta M.The aim of the present study was to evaluate clinical efficacy of constant rate infusions (CRIs) of medetomidine-propofol combined with sevoflurane anesthesia in Thoroughbred racehorses undergoing arthroscopic surgery. Thirty horses were sedated intravenously (IV) with medetomidine (6.0 μg/kg) and midazolam (0.02 mg/kg) and induced IV with ketamine (1.0 mg/kg) and propofol (1.0 mg/kg). These horses were randomly allocated to three groups and maintained with sevoflurane and CRI of either medetomidine (3.0 μg/kg/h) (Group M; n = 10); or medetomidine (3.0 μg/kg/h) and propofol (3.0 ...
Sage AM, Keating SC, Lascola KM, Schaeffer DJ, Clark-Price SC.To evaluate cardiopulmonary and recovery characteristics of horses administered total intravenous anesthesia (TIVA) with xylazine and ketamine combined with midazolam or propofol. Methods: Randomized crossover study. Methods: A group of eight adult horses, aged 7-22 years, weighing 493-740 kg. Methods: Horses were administered xylazine (1 mg kg) intravenously (IV), and anesthesia was induced with ketamine (2.2 mg kg) IV. Anesthesia was maintained for 45 minutes via IV infusion of xylazine (0.016 mg kg minute) and ketamine (0.03 mg kg minute) combined with midazolam at 0.002 mg kg minute (MKX),...
Jarrett MA, Bailey KM, Messenger KM, Prange T, Gaines B, Posner LP.OBJECTIVE To evaluate quality of recovery from general anesthesia in horses after induction with propofol and ketamine versus midazolam and ketamine. DESIGN Prospective randomized crossover study. ANIMALS 6 healthy adult horses. PROCEDURES Horses were premedicated with xylazine (1.0 mg/kg [0.45 mg/lb], IV), and general anesthesia was induced with midazolam (0.1 mg/kg [0.045 mg/lb], IV) or propofol (0.5 mg/kg [0.23 mg/lb], IV), followed by ketamine (3.0 mg/kg [1.36 mg/lb], IV). Horses were endotracheally intubated, and anesthesia was maintained with isoflurane. After 60 minutes, horses were giv...
Neudeck S, Kästner SBR, Wittenberg-Voges L, Rohn K, Hopster K.OBJECTIVE To determine global and peripheral perfusion and oxygenation during anesthesia with equipotent doses of desflurane and propofol combined with a constant rate infusion of dexmedetomidine in horses. ANIMALS 6 warmblood horses. PROCEDURES Horses were premedicated with dexmedetomidine (3.5 μg•kg, IV). Anesthesia was induced with propofol or ketamine and maintained with desflurane or propofol (complete crossover design) combined with a constant rate infusion of dexmedetomidine (7 μg•kg •h). Microperfusion and oxygenation of the rectal, oral, and esophageal mucosa were measured bef...
Aoki M, Wakuno A, Kushiro A, Mae N, Kakizaki M, Nagata SI, Ohta M.Anesthetic and cardiorespiratory effects of total intravenous anesthesia (TIVA) technique using propofol-guaifenesin-medetomidine (PGM) and alfaxalone-guaifenesin-medetomidine (AGM) were preliminarily evaluated in Thoroughbred horses undergoing castration. Twelve male Thoroughbred horses were assigned randomly into two groups. After premedication with intravenous (IV) administrations of medetomidine (5.0 µg/kg) and butorphanol (0.02 mg/kg), anesthesia was induced with guaifenesin (10 mg/kg IV), followed by either propofol (2.0 mg/kg IV) (group PGM: n=6) or alfaxalone (1.0 mg/kg IV) (group AGM...
Taylor PM, White KL, Fowden AL, Giussani DA, Bloomfield M, Sear JW.To characterize propofol anaesthesia in pregnant ponies. Methods: Fourteen pony mares, at 256 ± 49 days gestation, undergoing abdominal surgery to implant fetal and maternal vascular catheters. Methods: Pre-anaesthetic medication with intravenous (IV) acepromazine (20 µg kg), butorphanol (20 µg kg) and detomidine (10 µg kg) was given 30 minutes before induction of anaesthesia with detomidine (10 µg kg) and ketamine (2 mg kg) IV Maternal arterial blood pressure was recorded (facial artery) throughout anaesthesia. Arterial blood gas values and plasma concentrations of glucose, lactate, cort...
Wagner AE, Mama KR, Steffey EP, Brevard LF, Hellyer PW.To compare behavioral characteristics of induction and recovery in horses anesthetized with eight anesthetic drug protocols. Methods: Randomized prospective experimental study. Methods: Eight horses, 5.5 ± 2.4 years (mean ± SD) of age, and weighing 505 ± 31 kg. Methods: After xylazine pre-medication, each of eight horses was anesthetized on four occasions using one of eight different anesthetic induction protocols which incorporated various combinations of ketamine (KET), propofol (PRO), and thiopental (THIO): THIO 8 mg kg; THIO 6 mg kg + PRO 0.5 mg kg; THIO 4 mg kg + PRO 1 mg kg; THIO 2 mg...
Umar MA, Fukui S, Kawase K, Itami T, Yamashita K.Cardiovascular effects of total intravenous anesthesia using ketamine-medetomidine-propofol drug combination (KMP-TIVA) were determined in 5 Thoroughbred horses undergoing surgery. The horses were anesthetized with intravenous administration (IV) of ketamine (2.5 mg/kg) and midazolam (0.04 mg/kg) following premedication with medetomidne (5 µg/kg, IV) and artificially ventilated. Surgical anesthesia was maintained by controlling propofol infusion rate (initially 0.20 mg/kg/min following an IV loading dose of 0.5 mg/kg) and constant rate infusions of ketamine (1 mg/kg/hr) and medetomidine (1.25...
Ishizuka T, Tamura J, Nagaro T, Sudo K, Itami T, Umar MA, Miyoshi K, Sano T, Yamashita K.Effects of intermittent positive pressure ventilation (IPPV) on cardiopulmonary function were evaluated in horses anesthetized with total intravenous anesthesia using constant rate infusions of medetomidine (3.5 µg/kg/hr), lidocaine (3 mg/kg/hr), butorphanol (24 µg/kg/hr) and propofol (0.1 mg/kg/min) (MLBP-TIVA). Five horses were anesthetized twice using MLBP-TIVA with or without IPPV at 4-week interval (crossover study). In each occasion, the horses breathed 100% oxygen with spontaneous ventilation (SB-group, n=5) or with IPPV (CV-group, n=5), and changes in cardiopulmonary parameters were ...
Villalba M, Santiago I, Gómez de Segura IA.The aim of this investigation was to determine the isoflurane-sparing effect and impact on arterial blood pressure and anaesthetic recovery of a constant rate infusion of medetomidine-propofol in horses. In a prospective, crossover, randomised study, six healthy horses (mean ± SD age, 13.7 ± 7.7 years; weight, 433 ± 51 kg) were anaesthetised twice with isoflurane and were randomly assigned to receive one of two treatments on each occasion, at least 2 weeks apart. The first treatment was saline (CTL group) and the second a medetomidine-propofol infusion (MP group; 1.25 µg/kg...
Duke-Novakovski T, Palacios-Jimenez C, Wetzel T, Rymes L, Sanchez-Teran AF.To examine the cardiopulmonary effects of two anesthetic protocols for dorsally recumbent horses undergoing carpal arthroscopy. Methods: Prospective, randomized, crossover study. Methods: Six horses weighing 488.3 ± 29.1 kg. Methods: Horses were sedated with intravenous (IV) xylazine and pulmonary artery balloon and right atrial catheters inserted. More xylazine was administered prior to anesthetic induction with ketamine and propofol IV. Anesthesia was maintained for 60 minutes (or until surgery was complete) using either propofol IV infusion or isoflurane to effect. All horses were admi...
Posner LP, Kasten JI, Kata C.To document the suitability of intravenous propofol and ketamine following sedation with xylazine for routine anaesthetic induction in horses. Retrospective. 100 client-owned horses. Anaesthetic records were evaluated to determine: signalment, anaesthetic drug and dosages, need for additional induction agents, notation of any adverse events, duration of anaesthesia and recovery characteristics (rough or smooth, and rapid or prolonged). Horses were sedated with xylazine 0.99±(0.2) mg/kg intravenous and 23 horses were also administered butorphanol 0.02±(0.001) mg/kg intravenous. Horses were an...
Ferreira TH, Brosnan RJ, Shilo-Benjamini Y, Moore SB, Hollingsworth SR.To assess the effects of ketamine hydrochloride, propofol, or compounded thiopental sodium administration on intraocular pressure (IOP) and qualities of induction of and recovery from anesthesia in horses. Methods: 6 healthy adult horses. Methods: Horses were sedated with xylazine hydrochloride (0.5 mg/kg), and anesthesia was induced with guaifenesin followed by ketamine (2 mg/kg), propofol (3 mg/kg), or thiopental (4 mg/kg) in a crossover study with ≥ 1 week between treatments. For each horse, IOP in the right eye was measured with a handheld applanation tonometer before and after xylazine ...
Ishizuka T, Itami T, Tamura J, Saitoh Y, Saitoh M, Umar MA, Miyoshi K, Yamashita K, Muir WW.Anesthetic and cardiorespiratory effects of medetomidine, lidocaine, butorphanol and propofol total intravenous anesthesia (MLBP-TIVA) were evaluated in horses undergoing an experimental surgery. Ten horses were premedicated with an intravenous injection (IV) of medetomidine (5 µg/kg) and butorphanol (20 µg/kg). Anesthesia was induced by administration of 1% propofol (3 mg/kg, IV) at a rate of 1 mg/kg/min (n=5, group-1) or 2% propofol administered at a rate of 6 mg/kg/min (n=5, group-2) following administration of lidocaine (1 mg/kg, IV) and then maintained by infusions of propofol, medetomi...
Wagner AE, Mama KR, Steffey EP, Hellyer PW.To determine whether infusion of xylazine and ketamine or xylazine and propofol after sevoflurane administration in horses would improve the quality of recovery from anesthesia. Methods: 6 healthy adult horses. Methods: For each horse, anesthesia was induced by administration of xylazine, diazepam, and ketamine and maintained with sevoflurane for approximately 90 minutes (of which the last 60 minutes were under steady-state conditions) 3 times at 1-week intervals. For 1 anesthetic episode, each horse was allowed to recover from sevoflurane anesthesia; for the other 2 episodes, xylazine and ket...
Brosnan RJ, Steffey EP, Escobar A, Palazoglu M, Fiehn O.To evaluate whether guaifenesin can prevent adverse anesthetic induction events caused by propofol and whether a guaifenesin-propofol induction combination has brief cardiovascular effects commensurate with rapid drug washout. Methods: 8 healthy adult horses. Methods: Guaifenesin was administered IV for 3 minutes followed by IV injection of a bolus of propofol (2 mg/kg). Additional propofol was administered if purposeful movement was detected. Anesthesia was maintained for 2 hours with isoflurane or sevoflurane at 1.2 times the minimum alveolar concentration with controlled normocapnic ventila...
Oku K, Kakizaki M, Ono K, Ohta M.Seven Thoroughbred horses were castrated under total intravenous anesthesia (TIVA) using propofol and medetomidine. After premedication with medetomidine (5.0 µg/kg, intravenously), anesthesia was induced with guaifenesin (100 mg/kg, intravenously) and propofol (3.0 mg/kg, intravenously) and maintained with constant rate infusions of medetomidine (0.05 µg/kg/min) and propofol (0.1 mg/kg/min). Quality of induction was judged excellent to good. Three horses showed insufficient anesthesia and received additional anesthetic. Arterial blood pressure changed within an acceptable range in all horse...
Boscan P, Rezende ML, Grimsrud K, Stanley SD, Mama KR, Steffey EP.To define the pharmacokinetic profile of propofol 5% microemulsion formulation in horses. Methods: First, propofol was administered as bolus injection (2 mg kg(-1)) to six xylazine-sedated horses. Secondly, after sedation and bolus injection, propofol was maintained with continuous infusion for 3 h [8.1 (sd 3.2) mg kg(-1) h(-1)] to the same six horses. Thirdly, in two horses, a commercial propofol was used for comparison. Response to noxious stimulation was used to evaluate analgesia. Venous blood samples were obtained to measure propofol plasma concentration using liquid chromatography-mass s...
Steffey EP, Brosnan RJ, Galuppo LD, Mama KR, Imai A, Maxwell LK, Cole CA, Stanley SD.To characterize the behavior of horses recovering in the Anderson Sling Suspension System after 4 hours of desflurane anesthesia and postdesflurane intravenous (IV) administration of propofol and xylazine. Methods: Experimental study. Methods: Healthy horses (n=6), mean+/-SEM age 12.3+/-1.8 years; mean weight 556+/-27 kg. Methods: Each horse was anesthetized with xylazine, diazepam, and ketamine IV and anesthesia was maintained with desflurane in O(2). At the end of 4 hours of desflurane, each horse was positioned in the sling suspension system and administered propofol-xylazine IV. Recovery e...
YAMASHITA K, AKASHI N, KATAYAMA Y, UCHIDA Y, UMAR MA, ITAMI T, INOUE H, SAMS RA, MUIR WW.The bispectral index (BIS) was evaluated as an indicator of central nervous system (CNS) depression in horses anesthetized with propofol. Five non-premedicated horses were anesthetized with 7 mg/kg, IV propofol and the minimum infusion rate (MIR) of propofol required to maintain anesthesia was determined during intermittent positive pressure ventilation in each horse. The BIS was determined 20 min later and after stabilization at 2.0 MIR, 1.5 MIR, and 1.0 MIR. The BIS was also recorded after the cessation of propofol infusion when the horses regained spontaneous breathing and swallowing reflex...
Muir WW, Lerche P, Erichson D.Studies have demonstrated the clinical usefulness of propofol for anaesthesia in horses but the use of a concentrated solution requires further investigation. Objective: To determine the anaesthetic and cardiorespiratory responses to a bolus injection of 10% propofol solution in mature horses. Methods: Three randomised crossover experimental trials were completed. Trial 1: 6 horses were selected randomly to receive 10% propofol (2, 4 or 8 mg/kg bwt i.v.). Trial 2: 6 horses received 1.1 mg/kg bwt i.v. xylazine before being assigned at random to receive one of 5 different doses (1-5 mg/kg bwt) o...
Brosnan RJ, Steffey EP.We hypothesized that propofol can produce rapidly-reversible, dose-dependent standing sedation in horses. Methods: Prospective randomized, blinded, experimental trial. Methods: Twelve healthy horses aged 12 +/- 6 years (mean +/- SD), weighing 565 +/- 20 kg, and with an equal distribution of mares and geldings. Methods: Propofol was administered as an intravenous bolus at one of three randomized doses (0.20, 0.35 and 0.50 mg kg(-1)). Cardiovascular and behavioral measurements were made by a single investigator, who was blinded to treatment dose, at 3 minute intervals until subjective behavior s...
Steffey EP, Mama KR, Brosnan RJ, Imai A, Maxwell LK, Cole CA, Stanley SD.To compare characteristics of horses recovering from 4 hours of desflurane anesthesia with and without immediate postanesthetic IV administration of propofol and xylazine. Animals-8 healthy horses (mean +/- SEM age, 6.6 +/- 1.0 years; mean body weight, 551 +/- 50 kg). Methods: Horses were anesthetized twice. Both times, anesthesia was induced with a combination of xylazine hydrochloride, diazepam, and ketamine hydrochloride and then maintained for 4 hours with desflurane in oxygen. Choice of postanesthetic treatment was randomly assigned via a crossover design such that each horse received an ...
Umar MA, Yamashita K, Kushiro T, Muir WW.To evaluate the cardiovascular effects of total IV anesthesia with propofol (P-TIVA) or ketamine-medetomidine-propofol (KMP-TIVA) in horses. Methods: 5 Thoroughbreds. Methods: Horses were anesthetized twice for 4 hours, once with P-TIVA and once with KMP-TIVA. Horses were medicated with medetomidine (0.005 mg/kg, IV) and anesthetized with ketamine (2.5 mg/kg, IV) and midazolam (0.04 mg/kg, IV). After receiving a loading dose of propofol (0.5 mg/kg, IV), anesthesia was maintained with a constant rate infusion of propofol (0.22 mg/kg/min) for P-TIVA or with a constant rate infusion of propofol (...
Oku K, Ohta M, Katoh T, Moriyama H, Kusano K, Fujinaga T.We examined the influence of propofol infusion on cardiovascular system at the rate of 0.14, 0.20 and 0.30 mg/kg/min in six adult Thoroughbred horses. The cardiovascular parameters were heart rate (HR), mean arterial pressure (MAP), mean right atrial pressure (MRAP), stroke volume (SV), cardiac output (CO), systemic vascular resistance (SVR), pre-ejection period (PEP) and ejection time (ET). In order to keep the ventilation conditions constantly, intermittent positive pressure ventilation was performed, and the partial arterial CO(2) pressure was maintained at 45 to 55 mmHg during maintenance ...
Umar MA, Yamashita K, Kushiro T, Muir WW.Objective-To compare the anesthetic and cardiorespiratory effects of total IV anesthesia with propofol (P-TIVA) or a ketamine-medetomidine-propofol combination (KMP-TIVA) in horses. Design-Randomized experimental trial. Animals-12 horses. Procedure-Horses received medetomidine (0.005 mg/kg [0.002 mg/lb], IV). Anesthesia was induced with midazolam (0.04 mg/kg [0.018 mg/lb], IV) and ketamine (2.5 mg/kg [1.14 mg/lb], IV). All horses received a loading dose of propofol (0.5 mg/kg [0.23 mg/lb], IV), and 6 horses underwent P-TIVA (propofol infusion). Six horses underwent KMP-TIVA (ketamine [1 mg/kg/...
Mama KR, Steffey EP, Pascoe PJ.To evaluate selected hemodynamic, respiratory, and behavioral responses to propofol in horses premedicated with xylazine or detomidine. Methods: Xylazine (0.5 and 1.0 mg/kg of body weight) was administered IV on different days to each of 6 horses prior to IV administration of propofol (2 mg/kg). In a second group of 6 horses, detomidine (15 and 30 micrograms/kg) was similarly studied. Methods: 2 groups of 6 mature healthy horses. Methods: Rectal temperature, heart and respiratory rates, arterial blood gas tensions, and direct arterial blood pressures were recorded before and at fixed intervals...
YAMASHITA K, AKASHI N, KATAYAMA Y, UCHIDA Y, UMAR MA, ITAMI T, INOUE H, SAMS RA, MUIR WW.The bispectral index (BIS) was evaluated as an indicator of central nervous system (CNS) depression in horses anesthetized with propofol. Five non-premedicated horses were anesthetized with 7 mg/kg, IV propofol and the minimum infusion rate (MIR) of propofol required to maintain anesthesia was determined during intermittent positive pressure ventilation in each horse. The BIS was determined 20 min later and after stabilization at 2.0 MIR, 1.5 MIR, and 1.0 MIR. The BIS was also recorded after the cessation of propofol infusion when the horses regained spontaneous breathing and swallowing reflex...
Bettschart-Wolfensberger R, Kalchofner K, Neges K, Kästner S, Fürst A.To examine the clinical suitability of medetomidine-propofol infusions for total intravenous anaesthesia in horses. Methods: Fifty client-owned horses of mixed breed, age [mean +/- SD (range)] 6.6 +/- 4.4 (0.04-18) years, mass 478 +/- 168.3 (80-700) kg presented for a range of operations requiring general anaesthesia. Methods: Pre-anaesthetic medication was intravenous (IV) medetomidine 7 mug kg(-1). Anaesthesia was induced with IV ketamine (2 mg kg(-1)) and diazepam (0.02 mg kg(-1)). After endotracheal intubation, O2 was delivered (FiO2 > 0.85). Positive pressure ventilation was initiated if ...
Nolan A, Reid J, Welsh E, Flaherty D, McCormack R, Monteiro AM.The pharmacokinetics of propofol and ketamine administered together by infusion were investigated in four ponies. Blood propofol and plasma ketamine and norketamine concentrations were measured by high performance liquid chromatography. After premedication with detomidine (20 micrograms kg-1) anaesthesia was induced with ketamine (2.2 mg kg-1 intravenously). The trachea was intubated and the ponies were allowed to breathe 100 per cent oxygen. A bolus dose of propofol (0.5 mg kg-1) was then administered intravenously and propofol and ketamine were infused for 60 and 45 minutes, respectively. Th...
Wagner AE, Mama KR, Steffey EP, Hellyer PW.To determine whether infusion of xylazine and ketamine or xylazine and propofol after sevoflurane administration in horses would improve the quality of recovery from anesthesia. Methods: 6 healthy adult horses. Methods: For each horse, anesthesia was induced by administration of xylazine, diazepam, and ketamine and maintained with sevoflurane for approximately 90 minutes (of which the last 60 minutes were under steady-state conditions) 3 times at 1-week intervals. For 1 anesthetic episode, each horse was allowed to recover from sevoflurane anesthesia; for the other 2 episodes, xylazine and ket...
Steffey EP, Mama KR, Brosnan RJ, Imai A, Maxwell LK, Cole CA, Stanley SD.To compare characteristics of horses recovering from 4 hours of desflurane anesthesia with and without immediate postanesthetic IV administration of propofol and xylazine. Animals-8 healthy horses (mean +/- SEM age, 6.6 +/- 1.0 years; mean body weight, 551 +/- 50 kg). Methods: Horses were anesthetized twice. Both times, anesthesia was induced with a combination of xylazine hydrochloride, diazepam, and ketamine hydrochloride and then maintained for 4 hours with desflurane in oxygen. Choice of postanesthetic treatment was randomly assigned via a crossover design such that each horse received an ...
Nolan AM, Hall LW.The use of propofol, solubilised in a non-ionic emulsifying agent, for the induction and maintenance of anaesthesia in experimental ponies was assessed. Pilot studies revealed that premedication with xylazine (0.5 mg/kg bodyweight [bwt]) intravenously (iv) followed by propofol (2.0 mg/kg bwt) iv provided a satisfactory smooth induction. Two infusion rates (0.15 mg/kg bwt/min and 0.2 mg/kg bwt/min) were compared for maintenance of anaesthesia. An infusion rate of 0.2 mg/kg/min produced adequate anaesthesia in these ponies. Cardiovascular changes included a decrease in arterial pressure and card...
Umar MA, Yamashita K, Kushiro T, Muir WW.To evaluate the cardiovascular effects of total IV anesthesia with propofol (P-TIVA) or ketamine-medetomidine-propofol (KMP-TIVA) in horses. Methods: 5 Thoroughbreds. Methods: Horses were anesthetized twice for 4 hours, once with P-TIVA and once with KMP-TIVA. Horses were medicated with medetomidine (0.005 mg/kg, IV) and anesthetized with ketamine (2.5 mg/kg, IV) and midazolam (0.04 mg/kg, IV). After receiving a loading dose of propofol (0.5 mg/kg, IV), anesthesia was maintained with a constant rate infusion of propofol (0.22 mg/kg/min) for P-TIVA or with a constant rate infusion of propofol (...
Bettschart-Wolfensberger R, Bowen IM, Freeman SL, Weller R, Clarke KW.To search for long-term total i.v. anaesthesia techniques as a potential alternative to inhalation anaesthesia. Objective: To determine cardiopulmonary effects and anaesthesia quality of medetomidine-ketamine anaesthesia induction followed by 4 h of medetomidine-propofol anaesthesia in 6 ponies. Methods: Sedation consisted of 7 microg/kg bwt medetomidine i.v. followed after 10 min by 2 mg/kg bwt i.v. ketamine. Anaesthesia was maintained for 4 h with 3.5 microg/kg bwt/h medetomidine and propofol at minimum infusion dose rates determined by application of supramaximal electrical pain stimuli. Ve...
Oku K, Ohta M, Katoh T, Moriyama H, Kusano K, Fujinaga T.We examined the influence of propofol infusion on cardiovascular system at the rate of 0.14, 0.20 and 0.30 mg/kg/min in six adult Thoroughbred horses. The cardiovascular parameters were heart rate (HR), mean arterial pressure (MAP), mean right atrial pressure (MRAP), stroke volume (SV), cardiac output (CO), systemic vascular resistance (SVR), pre-ejection period (PEP) and ejection time (ET). In order to keep the ventilation conditions constantly, intermittent positive pressure ventilation was performed, and the partial arterial CO(2) pressure was maintained at 45 to 55 mmHg during maintenance ...
Sage AM, Keating SC, Lascola KM, Schaeffer DJ, Clark-Price SC.To evaluate cardiopulmonary and recovery characteristics of horses administered total intravenous anesthesia (TIVA) with xylazine and ketamine combined with midazolam or propofol. Methods: Randomized crossover study. Methods: A group of eight adult horses, aged 7-22 years, weighing 493-740 kg. Methods: Horses were administered xylazine (1 mg kg) intravenously (IV), and anesthesia was induced with ketamine (2.2 mg kg) IV. Anesthesia was maintained for 45 minutes via IV infusion of xylazine (0.016 mg kg minute) and ketamine (0.03 mg kg minute) combined with midazolam at 0.002 mg kg minute (MKX),...
Bettschart-Wolfensberger R, Bowen MI, Freeman SL, Feller R, Bettschart RW, Nolan A, Clarke KW.To determine cardiopulmonary effects of total IV anesthesia with propofol and medetomidine in ponies and effect of atipamezole on recovery. Methods: 10 ponies. Methods: After sedation was induced by IV administration of medetomidine (7 microg/kg of body weight), anesthesia was induced by IV administration of propofol 12 mg/kg) and maintained for 4 hours with infusions of medetomidine (3.5 microg/kg per hour) and propofol 10.07 to 0.11 mg/kg per minute). Spontaneous respiration was supplemented with oxygen. Cardiopulmonary measurements and blood concentrations of propofol were determined during...
Posner LP, Kasten JI, Kata C.To document the suitability of intravenous propofol and ketamine following sedation with xylazine for routine anaesthetic induction in horses. Retrospective. 100 client-owned horses. Anaesthetic records were evaluated to determine: signalment, anaesthetic drug and dosages, need for additional induction agents, notation of any adverse events, duration of anaesthesia and recovery characteristics (rough or smooth, and rapid or prolonged). Horses were sedated with xylazine 0.99±(0.2) mg/kg intravenous and 23 horses were also administered butorphanol 0.02±(0.001) mg/kg intravenous. Horses were an...
Mama KR, Pascoe PJ, Steffey EP, Kollias-Baker C.To characterize responses associated with two 1-hour total intravenous anesthesia techniques in horses. Methods: 6 mature, healthy mares. Methods: Each horse was anesthetized 3 times. Treatment order was determined by a series of Latin squares. After baseline measurements and instrumentation, horses were given xylazine (XYL) i.v.; anesthesia was induced 5 minutes later with 10% guaifenesin given i.v., then either ketamine (KET) or propofol (PRO) was given i.v. After anesthesia induction, each horse received an infusion of XYL and either KET or a low or high dose of PRO. Cardiopulmonary variabl...
Tokushige H, Okano A, Arima D, Ito H, Kambayashi Y, Minamijima Y, Ohta M.The aim of the present study was to evaluate clinical efficacy of constant rate infusions (CRIs) of medetomidine-propofol combined with sevoflurane anesthesia in Thoroughbred racehorses undergoing arthroscopic surgery. Thirty horses were sedated intravenously (IV) with medetomidine (6.0 μg/kg) and midazolam (0.02 mg/kg) and induced IV with ketamine (1.0 mg/kg) and propofol (1.0 mg/kg). These horses were randomly allocated to three groups and maintained with sevoflurane and CRI of either medetomidine (3.0 μg/kg/h) (Group M; n = 10); or medetomidine (3.0 μg/kg/h) and propofol (3.0 ...
Ohta M, Oku K, Mukai K, Akiyama K, Mizuno Y.To assess the clinical usability of propofol-ketamine anesthesia for internal fixation of fractures in racehorses, hemodynamics, blood pH and gases, and vital responses to the continuous intravenous anesthesia in 7 surgical cases were analyzed. The quality of induction with propofol was variable for individual horses. The vital signs reflecting circulation, breath, and anesthetic depth were kept good without any troubles throughout the surgery. Mean time from the end of anesthesia to standing up was prolonged, however recovery from anesthesia was calm and smooth in all cases. Propofol-ketamine...
Jarrett MA, Bailey KM, Messenger KM, Prange T, Gaines B, Posner LP.OBJECTIVE To evaluate quality of recovery from general anesthesia in horses after induction with propofol and ketamine versus midazolam and ketamine. DESIGN Prospective randomized crossover study. ANIMALS 6 healthy adult horses. PROCEDURES Horses were premedicated with xylazine (1.0 mg/kg [0.45 mg/lb], IV), and general anesthesia was induced with midazolam (0.1 mg/kg [0.045 mg/lb], IV) or propofol (0.5 mg/kg [0.23 mg/lb], IV), followed by ketamine (3.0 mg/kg [1.36 mg/lb], IV). Horses were endotracheally intubated, and anesthesia was maintained with isoflurane. After 60 minutes, horses were giv...
Boscan P, Rezende ML, Grimsrud K, Stanley SD, Mama KR, Steffey EP.To define the pharmacokinetic profile of propofol 5% microemulsion formulation in horses. Methods: First, propofol was administered as bolus injection (2 mg kg(-1)) to six xylazine-sedated horses. Secondly, after sedation and bolus injection, propofol was maintained with continuous infusion for 3 h [8.1 (sd 3.2) mg kg(-1) h(-1)] to the same six horses. Thirdly, in two horses, a commercial propofol was used for comparison. Response to noxious stimulation was used to evaluate analgesia. Venous blood samples were obtained to measure propofol plasma concentration using liquid chromatography-mass s...
Ishizuka T, Itami T, Tamura J, Saitoh Y, Saitoh M, Umar MA, Miyoshi K, Yamashita K, Muir WW.Anesthetic and cardiorespiratory effects of medetomidine, lidocaine, butorphanol and propofol total intravenous anesthesia (MLBP-TIVA) were evaluated in horses undergoing an experimental surgery. Ten horses were premedicated with an intravenous injection (IV) of medetomidine (5 µg/kg) and butorphanol (20 µg/kg). Anesthesia was induced by administration of 1% propofol (3 mg/kg, IV) at a rate of 1 mg/kg/min (n=5, group-1) or 2% propofol administered at a rate of 6 mg/kg/min (n=5, group-2) following administration of lidocaine (1 mg/kg, IV) and then maintained by infusions of propofol, medetomi...
Villalba M, Santiago I, Gómez de Segura IA.The aim of this investigation was to determine the isoflurane-sparing effect and impact on arterial blood pressure and anaesthetic recovery of a constant rate infusion of medetomidine-propofol in horses. In a prospective, crossover, randomised study, six healthy horses (mean ± SD age, 13.7 ± 7.7 years; weight, 433 ± 51 kg) were anaesthetised twice with isoflurane and were randomly assigned to receive one of two treatments on each occasion, at least 2 weeks apart. The first treatment was saline (CTL group) and the second a medetomidine-propofol infusion (MP group; 1.25 µg/kg...
Umar MA, Yamashita K, Kushiro T, Muir WW.Objective-To compare the anesthetic and cardiorespiratory effects of total IV anesthesia with propofol (P-TIVA) or a ketamine-medetomidine-propofol combination (KMP-TIVA) in horses. Design-Randomized experimental trial. Animals-12 horses. Procedure-Horses received medetomidine (0.005 mg/kg [0.002 mg/lb], IV). Anesthesia was induced with midazolam (0.04 mg/kg [0.018 mg/lb], IV) and ketamine (2.5 mg/kg [1.14 mg/lb], IV). All horses received a loading dose of propofol (0.5 mg/kg [0.23 mg/lb], IV), and 6 horses underwent P-TIVA (propofol infusion). Six horses underwent KMP-TIVA (ketamine [1 mg/kg/...
Taylor PM, White KL, Fowden AL, Giussani DA, Bloomfield M, Sear JW.To characterize propofol anaesthesia in pregnant ponies. Methods: Fourteen pony mares, at 256 ± 49 days gestation, undergoing abdominal surgery to implant fetal and maternal vascular catheters. Methods: Pre-anaesthetic medication with intravenous (IV) acepromazine (20 µg kg), butorphanol (20 µg kg) and detomidine (10 µg kg) was given 30 minutes before induction of anaesthesia with detomidine (10 µg kg) and ketamine (2 mg kg) IV Maternal arterial blood pressure was recorded (facial artery) throughout anaesthesia. Arterial blood gas values and plasma concentrations of glucose, lactate, cort...
Garcia Lascurain AA, Sumano Lopez H, Steffey EP, Santillán Doherty P, Hernandez EN.To characterize behavioral and physiological responses to short-term, unsupplemented intravenous (IV) anesthesia in healthy horses at high altitude (2240 m), and to test the hypothesis that the dose of butorphanol modifies the response of the horse to propofol anesthesia following xylazine pre-medication. Methods: Randomized prospective butorphanol dose cross-over experimental design. Animals Eight healthy horses, 13 +/- 6 (mean +/- SD) years of age, and weighing 523 +/- 26 kg. Methods: Each horse was anesthetized three times with at least 3 weeks between each anesthesia. After collecting pre-...
Brosnan RJ, Steffey EP, Escobar A, Palazoglu M, Fiehn O.To evaluate whether guaifenesin can prevent adverse anesthetic induction events caused by propofol and whether a guaifenesin-propofol induction combination has brief cardiovascular effects commensurate with rapid drug washout. Methods: 8 healthy adult horses. Methods: Guaifenesin was administered IV for 3 minutes followed by IV injection of a bolus of propofol (2 mg/kg). Additional propofol was administered if purposeful movement was detected. Anesthesia was maintained for 2 hours with isoflurane or sevoflurane at 1.2 times the minimum alveolar concentration with controlled normocapnic ventila...
Flaherty D, Reid J, Welsh E, Monteiro AM, Lerche P, Nolan A.The pharmacodynamics of infusions of propofol alone (group 1) were compared with the pharmacodynamics of infusions of propofol and ketamine together (group 2) in eight ponies undergoing castration. Anaesthesia was induced with detomidine, 20 micrograms kg-1, followed by ketamine, 2.2 mg kg-1. Subsequently, a bolus dose of propofol, 0.5 mg kg-1, was administered intravenously to both groups, and an infusion of propofol was given for an average of 74 minutes to group 1, and an infusion of propofol and ketamine was given for 60 minutes to group 2. The mean (SD) infusion rates of propofol were 0.3...
Oku K, Kakizaki M, Ono K, Ohta M.Seven Thoroughbred horses were castrated under total intravenous anesthesia (TIVA) using propofol and medetomidine. After premedication with medetomidine (5.0 µg/kg, intravenously), anesthesia was induced with guaifenesin (100 mg/kg, intravenously) and propofol (3.0 mg/kg, intravenously) and maintained with constant rate infusions of medetomidine (0.05 µg/kg/min) and propofol (0.1 mg/kg/min). Quality of induction was judged excellent to good. Three horses showed insufficient anesthesia and received additional anesthetic. Arterial blood pressure changed within an acceptable range in all horse...
Wagner AE, Mama KR, Steffey EP, Brevard LF, Hellyer PW.To compare behavioral characteristics of induction and recovery in horses anesthetized with eight anesthetic drug protocols. Methods: Randomized prospective experimental study. Methods: Eight horses, 5.5 ± 2.4 years (mean ± SD) of age, and weighing 505 ± 31 kg. Methods: After xylazine pre-medication, each of eight horses was anesthetized on four occasions using one of eight different anesthetic induction protocols which incorporated various combinations of ketamine (KET), propofol (PRO), and thiopental (THIO): THIO 8 mg kg; THIO 6 mg kg + PRO 0.5 mg kg; THIO 4 mg kg + PRO 1 mg kg; THIO 2 mg...
Duke-Novakovski T, Palacios-Jimenez C, Wetzel T, Rymes L, Sanchez-Teran AF.To examine the cardiopulmonary effects of two anesthetic protocols for dorsally recumbent horses undergoing carpal arthroscopy. Methods: Prospective, randomized, crossover study. Methods: Six horses weighing 488.3 ± 29.1 kg. Methods: Horses were sedated with intravenous (IV) xylazine and pulmonary artery balloon and right atrial catheters inserted. More xylazine was administered prior to anesthetic induction with ketamine and propofol IV. Anesthesia was maintained for 60 minutes (or until surgery was complete) using either propofol IV infusion or isoflurane to effect. All horses were admi...
Neudeck S, Kästner SBR, Wittenberg-Voges L, Rohn K, Hopster K.OBJECTIVE To determine global and peripheral perfusion and oxygenation during anesthesia with equipotent doses of desflurane and propofol combined with a constant rate infusion of dexmedetomidine in horses. ANIMALS 6 warmblood horses. PROCEDURES Horses were premedicated with dexmedetomidine (3.5 μg•kg, IV). Anesthesia was induced with propofol or ketamine and maintained with desflurane or propofol (complete crossover design) combined with a constant rate infusion of dexmedetomidine (7 μg•kg •h). Microperfusion and oxygenation of the rectal, oral, and esophageal mucosa were measured bef...
Oku K, Ohta M, Yamanaka T, Mizuno Y, Fujinaga T.To investigate an adequate infusion rate of propofol for total intravenous anesthesia (TIVA) in horses, the minimum infusion rate (MIR) comparable to the minimum alveolar anesthetic concentration (MAC) of inhalation anesthetic was determined under constant ventilation condition by intermittent positive pressure ventilation (IPPV). In addition, arterial propofol concentration was measured to determine the concentration corresponding to the MIR (concentration preventing reaction to stimulus in 50% of population, Cp(50)). Further, 95% effective dose (ED(95)) was estimated as infusion rate for acq...
