Evaluation of Ketamine Hydrochloride in Combination with Midazolam, Dexmedetomidine and Butorphanol as Balanced Anaesthesia in Cats

Background: As cats undergo stress at the time of presentation before surgery and therefore sedation is required often. It is very difficult to choose a balanced anaesthetic protocol during the surgical intervention in the case of a cat. Therefore, the present study was undertaken to evaluate the effect of ketamine hydrochloride in combination with midazolam, dexmedetomidine and butorphanol as balanced anaesthesia on clinico-physiological, haematological, serum biochemical profile in the surgical management of cats undergoing neutering. Methods: The study was performed on 18 clinical cases of cats which were brought to the Teaching Veterinary Clinical Complex, College of Veterinary Sciences and Animal Husbandry (CVSc and AH), Central Agricultural University (CAU), Selesih, Aizawl, Mizoram for elective surgery such as neutering. Cats were randomly divided into 3 equal groups, i.e. Gr. A, Gr. B and Gr. C. Animals were premedicated with glycopyrrolate @ 0.01 mg/kg, i/m. After 10 minutes of premedication, in Gr. A ketamine hydrochloride @15 mg/kg and midazolam @ 0.5 mg/kg, in Gr. B ketamine hydrochloride @10 mg/ kg and dexmedetomidine@ 5 mcg /kg and in Gr. C ketamine hydrochloride @ 5 mg/kg, dexmedetomidine@ 5 mcg/kg and butorphanol @ 0.2 mg/kg was administered intramuscularly. Clinico-physiological and haemato-biochemical profiles were evaluated at 0 minute (baseline), then at 15, 30 and 60 minutes after administration of anaesthetic agents to evaluate their anaesthetic effect. Result: In the case of time for induction, the quality of induction, assessment of peri-operative analgesia, depth of anaesthesia and quality of recovery there was no significant difference among all three groups. In Gr. B, animals showed significantly higher duration of recumbency (DOE) and recovery. The assessment of peri-operative analgesic effect among the groups revealed that analgesia during the perioperative period appeared best in Gr. C protocol. In regards to depth of anaesthesia, ketamine hydrochloride in combination with dexmedetomidine and butorphanol group showed a better result. Rectal temperature decreased significantly (P greater than 0.05) up to 60th minutes in Gr. A, but it remained within the physiological range. Heart rate raised significantly (p less than 0.05) from the baseline (0 minutes) onwards and decreased significantly (p less than 0.05) till the end (60 minutes) of the study in Gr. C. The respiration rate was significantly (p less than 0.01) different in between time intervals for all three groups. No significant difference was observed on haemato-biochemical observation except glucose level which significantly increased after induction of anaesthesia. In conclusion, treatment with ketamine hydrochloride in combination with dexmedetomidine and butorphanol led to acceptable sedation and mild changes in clinico-physiological, haematological, serum biochemical profile in comparison to the other two groups.

The Clinical Effect of Xylazine Premedication in Water Buffalo Calves (Bubalus bubalis) Undergoing Castration under General Anaesthesia

Castration is one of the most frequently performed surgical procedures in livestock. All methods of castration are associated with a significant degree of pain, affecting the patients’ welfare. Limited information on species-specific protocols in buffaloes is available. Considering the importance of this species and the scarcity of reports available, the objective of this study was to evaluate the effects of two different intramuscular doses of xylazine for premedication in water buffalo calves undergoing isoflurane maintenance anaesthesia for routine castration surgery. Twenty clinically healthy male water buffaloes undergoing bilateral orchiectomy were randomly assigned to two groups of 10 animals each: Group 1 was premedicated with xylazine 0.1 mg/kg bw i.m. and Group 2 was premedicated with xylazine 0.15 mg/kg bw i.m. Anaesthesia was induced by ketamine (2 mg/kg bw i.v.) and maintained with isoflurane-oxygen-air in both groups. The HR, RR, presence/absence of ataxia, sedation, depth of anaesthesia, muscle relaxation status, response to acoustic and tactile stimuli, eyelid reflex, extent of salivation and stimulus were evaluated every 5 min. Both protocols provided consistent sedation and were safe. Faster and more satisfactory sedation was recorded when xylazine was administered at 0.15 mg/kg bw i.m., leading us to recommend this dose for buffalo orchiectomy.

A survey of current practices, attitudes and demands of anaesthesiologists regarding the depth of anaesthesia monitoring in China

Background In this study, we aimed to analyse survey data to explore two different hypotheses; and for this purpose, we distributed an online survey to Chinese anaesthesiologists. The hypothetical questions in this survey include: (1) Chinese anaesthesiologists mainly use the depth of anaesthesia (DoA) monitors to prevent intraoperative awareness and (2) the accuracy of these monitors is the most crucial performance factor during the clinical daily practice of Chinese anaesthesiologists. Methods We collected and statistically analysed the response of a total of 12,750 anesthesiologists who were invited to participate in an anonymous online survey. The Chinese Society of Anaesthesiologists (CSA) trial group provided the email address of each anaesthesiologist, and the selection of respondents was random from the computerized system. Results The overall response rate was 32.0% (4037 respondents). Only 9.1% (95% confidence interval, 8.2-10.0%) of the respondents routinely used DoA monitors. Academic respondents (91.5, 90.3-92.7%) most frequently used DoA monitoring to prevent awareness, whereas nonacademic respondents (88.8, 87.4-90.2%) most frequently used DoA monitoring to guide the delivery of anaesthetic agents. In total, the number of respondents who did not use a DoA monitor and whose patients experienced awareness (61.7, 57.8-65.6%) was significantly greater than those who used one or several DoA monitors (51.5, 49.8-53.2%). Overall, the crucial performance factor during DoA monitoring was considered by 61.9% (60.4-63.4%) of the respondents to be accuracy. However, most respondents (95.7, 95.1-96.3%) demanded improvements in the accuracy of the monitors for DoA monitoring. In addition, broad application in patients of all ages (86.3, 85.2-87.4%), analgesia monitoring (80.4, 79.2-81.6%), and all types of anaesthetic agents (75.6, 74.3-76.9%) was reported. In total, 65.0% (63.6-66.5%) of the respondents believed that DoA monitors should be combined with EEG and vital sign monitoring, and 53.7% (52.1-55.2%) believed that advanced DoA monitors should include artificial intelligence. Conclusions Academic anaesthesiologists primarily use DoA monitoring to prevent awareness, whereas nonacademic anaesthesiologists use DoA monitoring to guide the delivery of anaesthetics. Anaesthesiologists demand high-accuracy DoA monitors incorporating EEG signals, multiple vital signs, and antinociceptive indicators. DoA monitors with artificial intelligence may represent a new direction for future research on DoA monitoring.

Conduct of anaesthesia

This chapter describes the safe conduct of general anaesthesia. Topics covered include induction of anaesthesia; maintenance of anaesthesia; total intravenous anaesthesia; and volatile anaesthetic agents. The important methods of monitoring the patient are discussed in detail, including monitoring of neuromuscular blockade, depth of anaesthesia and cardiac output. The measurement and control of patient temperature is described. The common surgical positions are described, together with their safety concerns. The chapter finishes with a discussion of the prevention and treatment of postoperative nausea and vomiting.

Effect of Fentanyl Infusion on Heart Rate Variability and Anaesthetic Requirements in Isoflurane-Anaesthetized Horses

Controversy continues to surround the use of opioids in equine anaesthesia, with variable effects reported. This blinded clinical study aimed to investigate the influence of a low-dose fentanyl continuous rate infusion (CRI) on isoflurane requirements, parasympathetic tone activity (PTA), and anaesthetic parameters in horses during general anaesthesia. All of the twenty-two horses included in the research underwent a standard anaesthetic protocol. Eleven horses in the fentanyl group (Group F) received a loading dose of fentanyl at 6 µg/kg, followed by a CRI of 0.1 µg/kg/min during anaesthesia. A further 11 horses in the control group (Group C) received equivalent volumes of normal saline. Anaesthetic parameters and PTA index were recorded during anaesthesia. The achieved mean fentanyl plasma concentration was 6.2 ± 0.83 ng/mL. No statistically significant differences between groups were found in isoflurane requirements, MAP values, and mean dobutamine requirements. However, horses in Group F required a significantly lower dose of additional ketamine to maintain a sufficient depth of anaesthesia. Significantly higher PTA values were found in the fentanyl group. Further research is warranted to determine the limitations of PTA monitoring, and the influence of various anaesthetics on its values.

Music to prevent deliriUm during neuroSurgerY (MUSYC) Clinical trial: a study protocol for a randomised controlled trial

IntroductionDelirium is a neurocognitive disorder characterised by an acute and temporary decline of mental status affecting attention, awareness, cognition, language and visuospatial ability. The underlying pathophysiology is driven by neuroinflammation and cellular oxidative stress.Delirium is a serious complication following neurosurgical procedures with a reported incidence varying between 4% and 44% and has been associated with increased length of hospital stay, increased amount of reoperations, increased costs and mortality.Perioperative music has been reported to reduce preoperative anxiety, postoperative pain and opioid usage, and attenuates stress response caused by surgery. We hypothesize that this beneficial effect of music on a combination of delirium eliciting factors might reduce delirium incidence following neurosurgery and subsequently improve clinical outcomes.MethodsThis protocol concerns a single-centred prospective randomised controlled trial with 6 months follow-up. All adult patients undergoing a craniotomy at the Erasmus Medical Center in Rotterdam are eligible. The music group will receive recorded music through an overear headphone before, during and after surgery until postoperative day 3. Patients can choose from music playlists, offered based on music importance questionnaires administered at baseline. The control group will receive standard of clinical careDelirium is assessed by the Delirium Observation Scale and confirmed by a delirium-expert psychiatrist according to the DSM-5 criteria. Risk factors correlated with the onset of delirium, such as cognitive function at baseline, preoperative anxiety, perioperative medication use, depth of anaesthesia and postoperative pain, and delirium-related health outcomes such as length of stay, daily function, quality of life (ie, EQ-5D, EORTC questionnaires), costs and cost-effectiveness are collected.Ethics and disseminationThis study is being conducted in accordance with the Declaration of Helsinki. The Medical Ethics Review Board of Erasmus University Medical Center Rotterdam, The Netherlands, approved this protocol. Results will be disseminated via peer-reviewed scientific journals and conference presentations.Trial registration numbersNL8503 and NCT04649450.

The Effect of Depth of Anaesthesia on the Severity of Mitral Insufficiency by Transesophageal Echocardiography

Background The assessment of mitral regurgitation (MR) is complex and complicated by the dynamic nature of this valvular abnormality. Intraoperative transesophageal echocardiography (TEE) is a well-established tool that is used to assess the mitral regurgitation (MR) before and after mitral valve reconstruction. Objectives This study conducted in the National Heart Institute in Cairo aimed at assessing the effect of depth of anaesthesia guided by bispectral index on the severity of mitral insufficiency as measured by transesophageal echocardiography. Patients and Methods This study was conducted in the National Heart Institute in Cairo. The study was conducted for a period of about six months after the approval from Ethical committee. Informed oral consent for every patient was obtained. Prospective observational cross-sectional study with a random sample of 20 patients at National Heart Institute. A sample size of at least 15 data pairs achieves 80% power to reject the null hypothesis of zero effect size when the population effect size is 0.80 and the significance level (alpha) is 0.05 using a two-sided paired ttest. Adult patients undergoing elective cardiac surgery in National Heart Institute. Results The MR severity decreased at a deeper anaesthesia at low BIS than at a shallower anaesthesia at high BIS in patients with organic MR. Eight patients out of twenty patients (40% with organic MR) showed a + 1 grade of improvement in MR grade, by semi-quantitively measuring maximal JA and VC width. Improvement in mitral regurge severity thought to be secondary to unloading effect of general anaesthesia on left ventricle causing a decrease in afterload, preload, and left ventricular dimensions. This study demonstrated that, a comparison between deep anaesthesia and shallow anaesthesia using BIS showed there is a significant reduction in multiple parameters of MR severity assessment secondary to unloading effect of general anaesthesia on left ventricle caused by a decrease in both afterload and preload. Conclusion This reduction in MR severity appeared to be significant enough to modify intraoperative decisions regarding valve surgery by underestimation of valve severity. Thus, strong consideration should be given to thorough preoperative assessment of MR severity, rather than relying on intraoperative findings.

Anaesthetic protocol for paediatric glaucoma examinations: the prospective EyeBIS Study protocol

IntroductionNeonates and young infants with diagnosed or highly suspected glaucoma require an examination under anaesthesia to achieve accurate intraocular pressure (IOP) measurements, since crying or squinting of the eyes may increase IOP and lead to falsely high values. IOP considerably depends on perioperative variables such as haemodynamic factors, anaesthetics, depth of anaesthesia and airway management. The aim of this paper is to report the design and baseline characteristics of EyeBIS, which is a study to develop a standardised anaesthetic protocol for the measurement of IOP under anaesthesia in childhood glaucoma, by investigating the link between the magnitude of IOP and depth of anaesthesia.Methods and analysisThis is a single-centre, prospective cohort study in 100 children with diagnosed or highly suspected glaucoma all undergoing ophthalmological examination under general anaesthesia. 20 children, who undergo general anaesthesia for other reasons, are included as controls. The primary outcome measure is the establishment of a standardised anaesthetic protocol for IOP measurement in childhood glaucoma by assessing the relationship between IOP and depth of anaesthesia (calculated as an electroencephalography variable, the bispectral index), with special emphasis on airway management and haemodynamic parameters. The dependence of IOP under anaesthesia on airway management and haemodynamic parameters will be described, using a mixed linear model. Restricting the model to patients with healthy eyes will allow to determine a 95% reference region, in which 95% of the measurement values of patients with healthy eyes can be expected.Ethics and disseminationThe study has been approved by the local ethics committee of the Medical Association of Rhineland-Palatine (Ethik-Kommisssion der Landesaerztekammer Rheinland-Pfalz), Germany (approval number: 2019-14207). This work will be disseminated by publication of peer-reviewed manuscripts, presentation in abstract form at national and international scientific meetings and data sharing with other investigators.Trial registration numberClinicalTrials.gov Registry (NCT03972852).

Evaluation of Tramadol, Pentazocine Lactate and Meloxicam as Pre-emptive Analgesics for Pain Management in Canine Ovariohysterectomy

Background: It is usually accepted that some degree of post-surgical pain will be commonly present. There are different pain scales adopted in veterinary practice to assess these behavioural signs to measure pain. VAS had been used in human medicine for many years to measure pain and was found equally satisfactory in dogs. Pre-emptive analgesia (PEA) is grasping popularity in recent days, the concept of which originated during the time of growing appreciation of dynamic characteristics of pain pathway for obtaining effective analgesia prior to the surgical trauma. Methods: The present study was conducted to evaluate the effects of tramadol, pentazocine lactate and meloxicam as pre-emptive analgesics in dogs premedicated with glycopyrrolate, induction and maintenance with propofol continuous rate infusion (CRI) for certain clinical and physiological parameters. The animals were randomly divided into three equal groups viz. Group-T, Group-P and Group-M comprising six animals in each group and all were premedicated with glycopyrrolate, I/M. After 10 minutes of pre-anaesthetic administration, pre-emptive analgesia was given (Tramadol in Group-T, Pentazocine lactate in Group-P and Meloxicam in Group-M intravenously). After 10 minutes of pre-emptive analgesic administration, induction was achieved with propofol I/V and also maintained by CRI method up to 1 hour. Clinical and physiological parameters were recorded at 0 (baseline) minute before premedication, thereafter at 10 min, 30 min, 1 hr, 2 hr and 3 hr after pre-emptive analgesic administration. Result: There was no sedation observed within 10 min following pre-emptive analgesia and quality of sedation was recorded as score-0 in all the groups. Time for induction was significantly higher in group-M as compared to group-T and P. Quality of induction in all the groups ranged from score-0 to score1, assessment of peri-operative analgesia was recorded as score-0 in group-T and group-P, whereas in group-M it ranged from score-0 to score-1. Depth of anaesthesia was recorded as score-0 to score-1 in all the groups and quality of recovery was recorded as score-0 to score-1 in group-T and group-P and score-1 to score-2 in group-M. Assessment of post-operative analgesia by VAS was significantly lower in group-T as compared to group-P and M. In all the three groups, the heart rate increased significantly at 30 min interval and thereafter it decreased significantly till the end of the study. Respiratory rate also decreased significantly till 1 hr and thereafter it gradually increased till the end of study in all the groups. Rectal temperature, SpO2, systolic pressure and diastolic pressure decreased significantly at 30 min and thereafter increased gradually and approached base values in all the groups.

Comparison of two injectable anaesthetic techniques on induction and subsequent anaesthesia in pigs

Pig experiments often require anaesthesia, and a rapid stress-free induction is desired. Induction drugs may alter the subsequent anaesthesia. Therefore, the aim of the present study was to compare, in pigs, the effects of two different injectable anaesthetic techniques on the induction and on the physiological variables in a subsequent eight hours of total intravenous anaesthesia (TIVA). Twelve domestic castrates (Swedish Landrace/Yorkshire) 27‒31 kg were used. The pigs were randomly assigned to different induction drug combinations of zolazepam–tiletamine and medetomidine intramuscularly (ZTMe) or midazolam, ketamine intramuscularly and fentanyl intravenously (MiKF). Time from injection to unconsciousness was recorded and the ease of endotracheal intubation assessed. The TIVA infusion rate was adjusted according to the response exhibited from the nociceptive stimulus delivered by mechanically clamping the dewclaw. The time from injection to unconsciousness was briefer and intubation was easier in the ZTMe group. Results from the recorded heart rate, cardiac index and arterial blood pressure variables were satisfactorily preserved and cardiovascular function was maintained in both groups. Shivering was not observed in the ZTMe group, but was observed in four of the pigs in the MiKF group. The requirement of TIVA was lower in the ZTMe group. In conclusion, ZTMe had better results than MiKF in areas such as shorter induction time, better intubation scoring results and less adjustment and amount of TIVA required up to six hours of anaesthesia. The results may have been due to a greater depth of anaesthesia achieved with the ZTMe combination at the dose used.