Risk of post-anaesthetic colic in horses anaesthetised with two different anaesthetic protocols : single-centre retrospective study

Nukutuksen jälkeinen ähky on yleisimpiä anestesia-komplikaatioita hevosilla. Erilaisten nukutusprotokollien vaikutusta nukutuksen jälkeisen ähkyn esiintyvyyteen hevosilla on tutkittu vain vähän. Kävimme läpi Helsingin Yliopiston Yliopistollisessa eläinsairaalassa 1.1.2013 – 31.12.2016 ortopediseen leikkaukseen, kastraatioon tai penisamputaatioon isofluraanilla ja joko lidokaiini (n = 106)- tai romifidiini-infuusiolla (n = 127) nukutettujen hevosten potilastiedot. Käytimme yhden muuttujan analyysiä sekä monimuuttuja-analyysiä selvittääksemme nukutuksen jälkeisen ähkyn ja seuraavien tekijöiden välistä yhteyttä: lidokaiini- tai romifidiini-infuusio, asepromatsiiniesilääkitys, hevoselle käytetty opioidi, paikallispuudutuksen käyttö, hevoselle käytetty tulehduskipulääke ja antibiootti, ikä, paino, sukupuoli, asento leikkauksen aikana, leikkauksen vuorokaudenaika, sairaalassaolo ennen leikkausta, vuodenaika, toimenpide, anestesian kesto ja leikkauksen jälkeisen sairaalassaoloajan pituus. Nukutuksen jälkeisen ähkyn esiintyvyys oli 6,87 % (n = 16). Esiintyvyys oli 3,77 % (n = 4) lidokaiini-infuusiolla nukutetuilla hevosilla ja 9.44 % (n = 12) romifidiini-infuusiolla nukutetuilla (p = 0,09). Tutkituista tekijöistä ainoastaan hevosen suuri paino tunnistettiin nukutuksen jälkeiselle ähkylle altistavaksi riskitekijäksi (vetosuhde 1,8 jokaiselle 100 kg:n nousulle painossa). Eri opioidit, asepromatsiini-esilääkitys ja sairaalassaoloaika ennen leikkausta olivat mahdollisia sekoittavia tekijöitä. Emme todenneet merkitseviä eroja nukutuksen jälkeisen ähkyn esiintyvyydessä lidokaiini- ja romifidiini-infuusiolla ja isofluraanilla nukutettujen hevosten välillä. Tarvitaan lisää prospektiivisia tutkimuksia, jotta voidaan paremmin selvittää eri nukutusprotokollien vaikutusta nukutuksen jälkeisen ähkyn esiintyvyyteen.Peer reviewe

Canine mammary tumour cells exposure to sevoflurane : effects on cell proliferation and neuroepithelial transforming gene 1 expression

Objective The influence of perioperative factors, such as anaesthetic and analgesic techniques, on metastatic spread following surgery for primary cancer removal is of growing interest. The present study investigated the effects of sevoflurane on canine mammary tumour cell proliferation (MTT colorimetric assay) and on the expression of neuroepithelial transforming gene 1 (NET1). Study design Prospective controlled in vitro trial. Study material Primary (CIPp) and metastatic canine tubular adenocarcinoma (CIPm) cells. Methods To perform MTT tests, cell lines were seeded at a density of 3000 cells per well and incubated with sevoflurane (1, 2.5 or 4 mM) or only with the culture medium (control). Sevoflurane was added to the cell cultures every hour to avoid changes in drug concentration. MTT assays were performed after 6 hours of exposure obtaining absolute values of absorbance. The RNA isolated from the lysates of the same cell lines underwent quantitative polymerase chain reaction to evaluate NET1 gene expression changes compared with controls. One-or two-way analysis of variance was used as appropriate (p <0.05). Results A significant increase in cell proliferation compared with controls was observed in CIPp treated with lower sevoflurane concentrations, whereas a significant decrease in cell proliferation was found in CIPm treated with all the sevoflurane concentrations. All CIPp treatments did not induce changes in gene expression compared with controls, whereas a significant increase in gene expression was observed in CIPm between controls and the higher sevoflurane concentration. Conclusions and clinical relevance Sevoflurane treatments modified the cell proliferation rate in both cell lines showing an increase or decrease when applied to CIPp or CIPm, respectively. Expression of the NET1 gene increased after treatment with sevoflurane 4 mM in metastatic cells. The role of sevoflurane on cancer recurrence should be further investigated.Peer reviewe

Stereoselective methadone disposition after administration of racemic methadone to anesthetized Shetland ponies assessed by capillary electrophoresis.

The enantioselectivity of the pharmacokinetics of methadone was investigated in anesthetized Shetland ponies after a single intravenous (0.5 mg/kg methadone hydrochloride; n = 6) or constant rate infusion (0.25 mg/kg bolus followed by 0.25 mg/kg/h methadone hydrochloride; n = 3) administration of racemic methadone. Plasma concentrations of l-methadone and d-methadone and their major metabolites, l- and d-2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), respectively, were analyzed by CE with highly sulfated γ-cyclodextrin as chiral selector and electrokinetic analyte injection from liquid/liquid extracts prepared at alkaline pH. In both trials, the d-methadone concentrations were lower than those of l-methadone and the d-EDDP levels were lower than those of L-EDDP. For the case of a single intravenous bolus injection, the plasma concentration versus time profile of methadone enantiomers was analyzed with a two-compartment pharmacokinetic model. l-methadone showed a slower elimination rate constant, a lower body clearance, and a smaller steady-state volume of distribution than d-methadone. d-methadone and d-EDDP were eliminated faster than their respective l-enantiomers. This is the first study that outlines that the disposition of racemic methadone administered to anesthetized equines is enantioselective

Trending ability and limitations of transpulmonary thermodilution and pulse contour cardiac output measurement in cats as a model for pediatric patients

The present study evaluated transpulmonary thermodilution (TPTD) and pulse contour cardiac output (PCCO) both measured by the PiCCO Plus™ monitor (Pulsion Medical Systems, Munich, Germany) against pulmonary artery thermodilution (PATD) in cats as a hemodynamic model for small children. A wide range of cardiac outputs (CO) was simultaneously measured. Accuracy and trending abilities were critically evaluated. Three cats were studied under isoflurane anesthesia and 160 CO measurements were performed with 3 mL ice-cold 5 % dextrose with PATD and TPTD. The results were compared with the PCCO measurement before the bolus measurement. Cardiac output was manipulated from 32 to 224 mL/kg/min by dobutamine, dopamine, phenylephrine, medetomidine and increased concentrations of isoflurane. Bland–Altman analysis, concordance and polar plot analysis were performed to assess accuracy and trending ability. TPTD was measuring constantly higher than PATD with a mean bias of 73 mL/kg/min and limits of agreement of 34–112 mL/kg/min, a concordance rate of 94 % and a mean polar angle of −5° with radial limits of agreement (RLOA) of 33°. Concordance rate of the PCCO versus PATD was 82 % with a mean polar angle of −10° and RLOA of 46° and versus TPTD 90 % with a mean polar angle of −6° and RLOA of 46°. Both tested methods constantly overestimated simultaneous PATD measurements. The small size, low flows and the relative short catheter not reaching the abdominal aorta may explain that. However TPTD tracked changes accurately opposed to a poor trending ability of the PCCO measurement

Combined caudal retrocostal and lateral ultrasound-guided approach for transversus abdominis plane injection: A descriptive pilot study in pig cadavers.

Transversus abdominis plane (TAP) block is a regional anesthetic technique used to desensitize the abdominal wall in several species. This study aimed to describe the anatomical characteristics of the abdominal wall and to identify a feasible approach for an US-guided TAP injection that would result in adequate staining of the relevant nerves in the abdominal wall in pig cadavers. Fresh cadavers from five Landrace pigs (age, 12 weeks; body weight, 35.5 ± 1.6 kg) were used. One pig (n = 1) was anatomically dissected, and four pigs (n = 4; i.e., 8 hemiabdomens) were used for TAP injections and evaluation of dye spread. The volume of 0.3 mL/kg/injection point of methylene blue was injected bilaterally. In the caudal retrocostal approach, the injection was performed ventral to the most caudal part of the costal arch. In the lateral approach, the injection was performed between the last rib and iliac crest. A needle was inserted in plane for the caudal retrocostal and the lateral approach caudocranially and craniocaudally, respectively. Successful staining was defined as presence of dye on the nerve for a length of >1 cm in its entire circumference. The TAP was found between different muscle layers in the described anatomical regions. In the caudal retrocostal approach the TAP was found between the external abdominal oblique and transversus abdominis muscle bellies. In the lateral approach the TAP was found between the internal abdominal oblique and transversus abdominis muscles. The approach combining lateral and caudal retrocostal injections at the studied volume stained a median of 5 (3-6) target nerves from the fourth-last thoracic nerve to L2 (six nerves). Combined caudal retrocostal and lateral TAP injections of 0.3 mL/kg/injection point, resulted in staining of target nerve branches which supply the periumbilical and caudal abdominal wall in pig cadavers

Enantioselective capillary electrophoresis for pharmacokinetic analysis of methadone and 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine in equines anesthetized with ketamine and isoflurane.

An enantioselective assay for the determination of methadone and its main metabolite 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine in equine plasma based on capillary electrophoresis with highly sulfated γ-cyclodextrin as chiral selector and electrokinetic analyte injection is described. The assay is based on liquid/liquid extraction of the analytes at alkaline pH from 0.1 mL plasma followed by electrokinetic sample injection of the analytes from the extract across a buffer plug without chiral selector. Separation occurs cationically at normal polarity in a pH 3 phosphate buffer containing 0.16% (w/v) of highly sulfated γ-cyclodextrin. The developed assay is precise (intra- and interday RSD < 4% and < 7%, respectively), is capable to determine enantiomer levels of methadone and 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine in plasma down to 2.5 ng/mL, and was successfully applied to monitor enantiomer drug and metabolite levels in plasma of a pony that was anesthetized with racemic ketamine and isoflurane and received a bolus of racemic methadone and a bolus followed by constant rate infusion of racemic methadone. The data suggest that the assay is well suited for pharmacokinetic purposes

Cardiopulmonary effects and anaesthesia recovery quality in horses anaesthetized with isoflurane and low-dose S-ketamine or medetomidine infusions

OBJECTIVES To evaluate cardiopulmonary effects and anaesthesia recovery quality in horses anaesthetized with isoflurane receiving medetomidine or S-ketamine infusions. STUDY DESIGN Randomized, blinded, prospective clinical trial. ANIMALS Fifty horses undergoing elective surgery. METHODS After acepromazine and flunixin meglumine premedication, horses received medetomidine (7 μg kg(-1) ) intravenously (IV). Anaesthesia was induced with midazolam and racemic ketamine (Med treatment group; 2.2 mg kg(-1) ; n = 25) or S-ketamine (S-ket treatment group; 1.1 mg kg(-1) ; n = 25) IV and maintained with isoflurane in oxygen/air and medetomidine (Med; 3.5 μg kg(-1) hour(-1) ) or S-ketamine (S-ket; 0.5 mg kg(-1) hour(-1) ). All horses were mechanically ventilated. Cardiopulmonary variables were evaluated. Isoflurane end-tidal concentrations (Fe'Iso), dobutamine requirements and thiopental boli were recorded. Plasma samples were collected in six horses to evaluate S-ketamine and S-norketamine concentrations. After surgery, medetomidine 2 μg kg(-1) was administered IV. Four independent observers scored recovery using a visual analogue scale and a numerical rating scale. RESULTS Both groups required similar mean Fe'Iso (1%). However, S-ket horses needed more thiopental boli. Median intraoperative cardiac index values were higher with S-ket (4.5 L minute(-1)  m(-2) ) than Med (3.9 L minute(-1)  m(-2) ). Overall, there were no differences in heart rate, blood pressure or dobutamine requirements; however, horses in S-ket showed higher heart rate values at 30 minutes after anaesthesia induction. Compared with Med horses, S-ket horses showed decreased PaO2 and increased pulmonary venous admixture values estimated with the Fshunt calculation. Recoveries were shorter and of poorer quality with S-ket. During infusion, S-ketamine and S-norketamine plasma concentrations lay in the ranges of 0.209-0.917 μg mL(-1) and 0.250-0.723 μg mL(-1) , respectively. CONCLUSIONS AND CLINICAL RELEVANCE Despite the higher intraoperative cardiac index with S-ket, both protocols were considered to provide acceptable cardiovascular function. However, recovery quality was significantly better in the Med group

Cardiopulmonary effects and anaesthesia recovery quality in horses anaesthetized with isoflurane and low‐dose S‐ketamine or medetomidine infusions

OBJECTIVES: To evaluate cardiopulmonary effects and anaesthesia recovery quality in horses anaesthetized with isoflurane receiving medetomidine or S-ketamine infusions. STUDY DESIGN: Randomized, blinded, prospective clinical trial. ANIMALS: Fifty horses undergoing elective surgery. METHODS: After acepromazine and flunixin meglumine premedication, horses received medetomidine (7 μg kg-1 ) intravenously (IV). Anaesthesia was induced with midazolam and racemic ketamine (Med treatment group; 2.2 mg kg-1 ; n = 25) or S-ketamine (S-ket treatment group; 1.1 mg kg-1 ; n = 25) IV and maintained with isoflurane in oxygen/air and medetomidine (Med; 3.5 μg kg-1 hour-1 ) or S-ketamine (S-ket; 0.5 mg kg-1 hour-1 ). All horses were mechanically ventilated. Cardiopulmonary variables were evaluated. Isoflurane end-tidal concentrations (Fe'Iso), dobutamine requirements and thiopental boli were recorded. Plasma samples were collected in six horses to evaluate S-ketamine and S-norketamine concentrations. After surgery, medetomidine 2 μg kg-1 was administered IV. Four independent observers scored recovery using a visual analogue scale and a numerical rating scale. RESULTS: Both groups required similar mean Fe'Iso (1%). However, S-ket horses needed more thiopental boli. Median intraoperative cardiac index values were higher with S-ket (4.5 L minute-1 m-2 ) than Med (3.9 L minute-1 m-2 ). Overall, there were no differences in heart rate, blood pressure or dobutamine requirements; however, horses in S-ket showed higher heart rate values at 30 minutes after anaesthesia induction. Compared with Med horses, S-ket horses showed decreased PaO2 and increased pulmonary venous admixture values estimated with the Fshunt calculation. Recoveries were shorter and of poorer quality with S-ket. During infusion, S-ketamine and S-norketamine plasma concentrations lay in the ranges of 0.209-0.917 μg mL-1 and 0.250-0.723 μg mL-1 , respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Despite the higher intraoperative cardiac index with S-ket, both protocols were considered to provide acceptable cardiovascular function. However, recovery quality was significantly better in the Med group