Anesthesia In Dogs Research Articles

Propofol total intravenous anaesthesia in dogs undergoing elective surgery, a comparison of MADTC and conventional variable rate infusion

Propofol total intravenous anaesthesia in dogs undergoing elective surgery, a comparison of MADTC and conventional variable rate infusion

Electroencephalographic and Cardiovascular Assessments of Isoflurane-Anesthetized Dogs.

This study investigated the use of frontal electroencephalography (EEG) to monitor varying levels of isoflurane anesthesia in dogs. The patient state index (PSI), burst suppression ratio (SR), and waveforms, were continuously recorded while mean arterial blood pressure (MBP), heart rate, responses to electric stimuli, and subjective anesthetic "depth" were assessed every 3 min. At deep anesthesia (2.5× MAC - 3.2%), the PSI (6.5 ± 10.8) and MBP (45.6 ± 16.4 mmHg) were the lowest, and SR was the highest (78.3 ± 24.0%). At 1× MAC (1.3%), the PSI and MBP increased significantly to 47.8 ± 12.6 and 99.8 ± 13.2, respectively, and SR decreased to 0.5 ± 2.5%. The EEG was predominantly isoelectric at 2×-2.5× MAC, indicating unconsciousness and unresponsiveness. As anesthesia lightened, waveforms transitioned to flatter and faster activity patterns with a response to noxious stimuli, suggesting regained consciousness. The PSI and MBP exhibited a stronger correlation (ρ = 0.8098, p = 0.001) than the relationship of PSI with heart rate (ρ = -0.2089, p = 0.249). Five of the six dogs experienced rough recovery, possibly due to high SR and low MBP. These findings suggest that EEG monitoring in dogs can be a valuable tool for the real-time tracking of brain states and can be used to guide the management of isoflurane anesthesia.

The effects of general anaesthesia on body temperature of dogs subjected to ovariohysterectomy or orchiectomy performed by veterinary students in a teaching hospital

Hypothermia during anaesthesia is a significant concern in veterinary practice, as it can lead to various complications, making it essential to understand the factors that contribute to temperature regulation in animals undergoing surgical procedures. This retrospective study aimed to evaluate the change in body temperature over the course of anaesthesia in dogs undergoing elective ovariohysterectomy and orchiectomy, and determine the effect of gender, dose of premedication, weight, age and duration of anaesthesia of the change of body temperature over time. One-hundred and ten dogs (n=110) that underwent elective ovariohysterectomy (n=75) and orchiectomy (n=35) surgery performed by veterinary students at the University of Adelaide were enrolled in this study. Dogs’ anaesthesia records were evaluated for change in body temperature over the course of anaesthesia, and correlated with gender, two premedication doses of acepromazine (mg/kg), body weight (kg), age (months) and anaesthesia times (minutes). The analyses were performed at TPm (temperature at premedication), T0 (induction), T15, T30, T60, T90, T120 and TRec (recovery) minutes. Statistical analysis was performed using the GenStat software and included repeated measures analysis and ANOVA. Significance was considered when p < 0.05. The data showed a significant time-by-gender interaction with female dogs experienced a greater degree of heat loss than male dogs at T60 (p<0.01), T90 (p<0.01) and T120 (p<0.01). At recovery, female average temperature was higher than in males (p<0.01). There was no significant difference in body temperature when other covariates were used in the analysis. The core body temperature of female dogs decreased significantly over time compared to males, with the most pronounced differenced during the intraoperative period. However, the study’s retrospective nature and limited sample size may influence the generalizability of these findings.

Evaluation of intravenous Acepromazine-Butorphanol-Propofol anaesthesia on Canine serum biochemistry

In order to increase accuracy and ensure safety during surgical procedures, anaesthesia is a necessary precondition for most diagnostic and surgical procedures in humans and animals. This study was designed to determine the changes in serum biochemical parameters following Acepromazine-Butorphanol-Propofol (ABP-combination) and propofol alone (PRO alone) anaesthesia in dogs. Ten (10) apparently healthy dogs with mean age of 1.59±0.77 years and a mean body weight of 15.5±1.96 kg were obtained from live dog market in Maiduguri, North-eastern Nigeria. The dogs were divided randomly into two groups, ABP-combination and PRO-alone groups. Following premedication with Acepromazine at 0.02mg/kg and Butorphanol at 0.05mg/kg iv., 4mg/kg Propofol was used to induce total intravenous anaesthesia (TIVA) after five minutes of premedication in ABP-combination group, while PRO-alone at 6mg/kg was used to induce anaesthesia without premedication in PRO-alone group. Creatinine (sCr), Alanine aminotransferase (ALT) and Blood urea nitrogen (BUN) were determined using standard laboratory procedures. The ALT, sCr and BUN showed no difference (p&gt;0.05) within the group but were significantly (p&lt;0.05) different between the groups. The levels of Alanine aminotransferase in both ABP and PRO treatments showed significant difference (p&lt;0.05) at 10minutes, 1hour, 6hrs and 24hours. Significant difference (p&lt;0.05) was observed in sCr levels between the two treatments, at 10minutes, 1hour and 6hours respectively. Blood urea nitrogen in both treatments differed (p&lt;0.05) significantly at 6hours and 24hours post anaesthesia. The results of this study showed that ABP-combination following TIVA provides transient non-significant (p&gt;0.05) effect on serum biochemical parameters. Therefore, the combination of ABP can be used during surgical procedures in dog.

The perfusion index as a method of assessing epidural anaesthesia efficacy in healthy dogs

Abstract Introduction Perfusion index (PI) is used as assessment of epidural anaesthesia efficacy in human medicine, but its usefulness in dogs is unknown. The aim of this study was to evaluate the usefulness of PI in determining epidural anaesthesia effectiveness. Material and Methods This is prospective cross-over experimental study. Five healthy adult beagle dogs were anaesthetised and an epidural catheter was inserted in the lumbosacral area and adjusted so that the end of the catheter was placed at the fourth lumbar vertebra. Single-port catheters were used in the control group and multiple-port catheters were used in the treatment group. A PI probe was placed on a hind leg, and the catheter placement was confirmed via computed tomography. The treatment group received a bolus dose of lidocaine, and the control group received saline, via epidural catheter. The PI value was recorded every 5 min until 30 min after lidocaine injection. Results The PIs of the hind limbs were not significantly different over time, nor were they between the control and lidocaine-injected groups at any point in time. Conclusion The PI is not useful in determining the efficacy of epidural anaesthesia in dogs under general anaesthesia. In the future, finding a reliable method to evaluate the success of regional anaesthesia, even in patients under general anaesthesia, will be necessary.

SimuVet: a preliminary study of the innovative development of a simulator for epidural anesthesia training in dogs.

Epidural anesthesia in dogs is a locoregional anesthesia technique used in veterinary medicine, becoming an important integrated application in the anesthetic protocol to provide safer and more effective analgesia to patients. For this, professionals must adhere to rigorous guidelines and possess technical skills. In this context, in veterinary education, the development of practical clinical skills represents a crucial aspect in the training of these professionals. However, traditional teaching methods have proven insufficient to ensure a consistent level of competence among recent graduates. The introduction of non-animal alternatives for educational purposes has contributed to the development of simulation-based teaching, an innovative and accessible field capable of enhancing pre-clinical proficiency in students and reducing the use of live animals and cadavers. Despite its application in various areas of veterinary education, there are no conclusive results regarding the development of accessible simulators capable of effectively enhancing training in epidural anesthesia in dogs. Therefore, this article represents a pioneering study aimed at sharing a method for creating SimuVet, a realistic simulator for training epidural anesthesia in dogs. The simulator was fully developed by veterinary researchers with limited experience in 3D printing and, after preliminary analysis, demonstrated excellent performance and ultrasonographic anatomy. Future work will focus on the formal validation of this simulator with the aim of improving the teaching and learning process for students and experts in performing epidural anesthesia in companion animals.

Effect of body position on transesophageal atrial pacing in dogs

ObjectiveTo evaluate the effect of body position on transesophageal atrial pacing (TEAP) in dogs. Study designProspective, experimental trial. AnimalsA total of eight mixed-breed dogs, median body mass 25 kg (range 11–31 kg). MethodsTEAP was performed using a 6 Fr (2 mm) pacing catheter introduced transorally and positioned in the lower esophagus in left lateral recumbency. The catheter was withdrawn in 5 mm increments until successful TEAP. The minimum pacing threshold (MPT) was determined at each 5 mm increment until atrial capture could not be achieved at a maximal pulse amplitude of 40 mA. The zone of capture (ZOC) was the total distance over which TEAP was achieved. The same process was repeated in right lateral, ventral and dorsal recumbency. A linear mixed model was used to assess the impact of body position on TEAP and ZOC. ResultsTEAP was achieved in all body positions. There was significant random effect of individual dogs on ZOC (p = 0.048) but not on MPT (p = 0.109). MPT was 11.56 ± 8.65 mA (mean ± SD), 8.43 ± 2.29 mA, 10.63 ± 6.91 mA and 10 ± 7.44 mA for dorsal, left and right lateral, and ventral recumbency, respectively. ZOC was 5.12 ± 2.08 cm, 6.35 ± 2.41 cm, 5.94 ± 3.23 cm and 5.31 ± 2.2 cm for dorsal, left lateral and right lateral, and ventral recumbency, respectively. Neither ZOC (p = 0.363) nor MPT (p = 0.716) varied significantly between body positions. Conclusions and clinical relevanceTEAP can be performed successfully in all body positions in dogs. Body position did not significantly influence MPT or ZOC values for TEAP. Further studies are needed to compare the efficacy of TEAP with the efficacy of standard pharmacological therapy for management of bradycardia during general anesthesia in dogs.

Clinical Anesthetic Evaluation of Pregabalin as Premedication for Ketamine-Induced General Anesthesia in Dogs and Cats

Clinical Anesthetic Evaluation of Pregabalin as Premedication for Ketamine-Induced General Anesthesia in Dogs and Cats

Effect of Glycopyrrolate-xylazine Supplementation on Zoletil-induced Total Intramuscular Anaesthesia in Dogs

Background: Zoletil has been used at different dose rates with or without preanaesthetics through intramuscular or intravenous routes in canine patients with varying results in other countries. The doses recommended by the manufacturer as well as researchers and the observations on various clinico-physiological and hemodynamic parameters are also highly variable. Keeping these points in mind, the present study was conducted to study anesthetic/sedative effects of intramuscular administration of Zoletil (20 mg/kg) and also to study the effect of glycopyrrolate (0.005 mg/kg)-xylazine (0.5 mg/kg) supplementation on Zoletil (10 mg/kg)-induced total intramuscular anesthesia in dogs. Methods: Fourteen canine patients were divided into two groups, viz., A and B, with seven animals in each group.In group A, Zoletil (tiletamine-zolazepam) at the dose rate of 20 mg/kg body weight was administered intramuscularly as an anaesthetic. In group B, preanesthetic glycopyrrolate at 0.005 mg/kg body weight was administered intramuscularly. After 15 minutes, xylazine at 0.5 mg/kg body weight was administered intramuscularly. After 15 minutes of preanesthetic administration in the B group, anaesthesia was induced intramuscularly with tiletamine-zolazepam @ 10 mg/kg body weight. Result: Zoletil (Tiletamine-zolazepam, 20 mg/kg IM) (group A) is only recommended for non-surgical/diagnostic (viz. Gastro-intestinal endoscopy)/minor surgical procedures in uncooperative dogs. An intramuscular anaesthetic protocol using glycopyrrolate (0.005 mg/kg)-xylazine (0.5 mg/kg) - Zoletil (10 mg/kg IM) (group B) is recommended for major surgical procedures of long duration. Neither the anaesthetic protocol produced any serious deleterious effect on hemato-biochemical and hemodynamic parameters; hence both protocols can be used safely in dogs as per the requirements of the procedure.

Evaluation of the Quality of Recovery from General Anesthesia in Dogs with Two Different Low Doses of Dexmedetomidine.

The purpose of this study was to evaluate the quality of recovery from general anesthesia with the administration of two low doses of dexmedetomidine in canine patients. For this blind randomized clinical trial study, 30 dogs undergoing general anesthesia for diagnostic procedures or elective surgery (ovariectomy/castration) were included. The patients were randomly divided into three groups, and at the end of anesthesia, they received a bolus of dexmedetomidine at 1 mcg/kg IV (D1), or a bolus of dexmedetomidine at 0.5 mcg/kg (D0.5), or a bolus of NaCl, in a total of 0.5 mL of solution for all three groups. After administration of the bolus, the anesthetist monitored the patients every 5 min by measuring heart rate, systolic and mean blood pressure, respiratory rate, and oxygen saturation. The quality of recovery was also assessed using 4 different scales. The extubation time, time of headlift, and standing position were also recorded. Both groups receiving dexmedetomidine had better awakening and a lower incidence of delirium when compared to saline administration. The heart rate was lower, while the systolic pressure was higher in the two groups D1 and D0.5 compared to the NaCl with a low presence of atrioventricular blocks. The extubation time resulted significantly higher in the D1 (17 ± 6 min) compared to the D0.5 (10 ± 4 min) and NaCl (8 ± 3 min) (p < 0.0001); the headlift time D1 (25 ± 10 min) resulted significantly longer than the NaCl group (11 ± 5 min) (p = 0.0023) but not than the D0.5 (18 ± 9 min). No significant differences were found among the three groups for standing positioning (D1 50 ± 18 min, D0.5 39 ± 22 min, NaCl 28 ± 17 min). The preventive administration of a bolus of dexmedetomidine at a dosage of 0.5 mcg/kg or 1 mcg/kg IV during the recovery phase improves the quality of recovery in patients undergoing general anesthesia.

Effect of Butorphanol-Medetomidine and Butorphanol-Dexmedetomidine on Echocardiographic Parameters during Propofol Anaesthesia in Dogs.

This study compared the effects of butorphanol-medetomidine and butorphanol-dexmedetomidine combinations on echocardiographic parameters during propofol anaesthesia in dogs. The dogs were randomly divided into two groups. In the butorphanol-medetomidine (BM) group, butorphanol (0.2 mg/kg) and medetomidine (15 μg/kg) were intravenously administered; in the butorphanol-dexmedetomidine (BD) group, butorphanol (0.2 mg/kg) and dexmedetomidine (7.5 μg/kg) was used. Anaesthesia was induced with propofol and maintained with a constant-rate infusion of propofol (0.2 mg/kg/min). The echocardiographic parameters were assessed in conscious dogs (T0). Echocardiography was conducted again at 10 min post premedication (T1), followed by assessments at 30 (T2), 60 (T3), and 90 (T4) mins. The dogs were subjected to diagnostic procedures (radiography, computed tomography) under anaesthesia. A significant reduction in heart rate and cardiac output was noted in both groups at T1. There was no significant difference in the stroke volume between the BM and BD groups. The application of butorphanol-dexmedetomidine caused a significant increase in the left ventricular internal diameter in diastole and the diameter of the left atrium compared to that caused by butorphanol-medetomidine. This study documented that butorphanol-medetomidine and butorphanol-dexmedetomidine combinations caused similar reductions in heart rate and cardiac output in both groups. 'New´ valvular regurgitation occurred following their administration.

Perceptions and opinions of pet caregivers in mainland and Hong Kong China about surgery, pain management, and anesthesia in dogs and cats

Small animal caregivers’ perceptions and previous life experiences play a pivotal role in patient care, making effective communication fundamental within the veterinary business. Despite the large and growing scale of the pet industry, data on small animal client-centered information about veterinary services in Mainland China (MC) and the Hong Kong Special Administrative Region (HKSAR) China are lacking. The objective of this study was to investigate the perceptions and opinions of small animal caregivers about surgery, pain management, and anesthesia in dogs and cats in these geographical regions through a validated online survey using content validity index. A total of 2080 valid answers were collected by convenience sampling over 45 days. Descriptive statistics were used to summarize data; the chi-square test and generalized linear models were used to test the associations between demographics and responses. Overall, caregivers appeared favorable toward the use of analgesia in their pets, with concerns over the potential adverse effects produced by analgesic drugs. Joint pain and ear infections were generally rated as conditions that would be less prone to require analgesia. Significant associations were observed for demographic factors such as gender, age, and geographical area, whether participants were healthcare providers, and whether their pets had undergone surgery before. Although many respondents expressed uncertainty in recognizing pain in their pets and administering analgesics, they also expressed a desire to learn and to be informed. This study highlights areas and factors that may determine the perceptions and opinions of small animal caregivers that form a unique human-animal bond in China. Client communication should be addressed on a case-by-case basis and adapted to the geographical area, as the individual background and demographics may have an ultimate impact on treatment goals and patient care.

Clinico-Physiological and Haemodynamic Alterations Following Propofol Induction and Premedication with Butorphanol, Dexmedetomidine or Acepromazine in Dogs

The present study was conducted during February-October 2021 at Department of Veterinary Surgery and Radiology, College of Veterinary Science &amp; A.H. Anjora, Durg (C.G.), India to evaluate the alternations on clinico-physiological and haemodynamic parameters following propofol induction in dogs premedicated with butorphanol or dexmedetomidine or acepromazine. Eighteen adult dogs of either sex were randomly divided into three groups (BP, DP and AP) with six animals in each. Ten minutes prior to the anaesthetic administration, all the dogs were administered glycopyrrolate @ 0.02 mg kg-1 I/M. The animals of group BP, DP and AP were premedicated intramuscularly with butorphanol @ 0.3 mg kg-1 b.wt., dexmedetomidine @ 10 µg kg-1 b.wt. and acepromazine @ 0.4 mg kg-1 b.wt. respectively. General anaesthesia was induced with propofol @ 7 mg kg-1 b.wt. intravenously. Clinical parameters were recorded following induction with propofol. Physiological and haemodynamic parameters were recorded before (0), 5 min. after sedation, induction and at 10, 20, 40, 60 and 120 min. post propofol anaesthesia. The onset of sedation and anaesthesia was quicker in group DP followed by AP and BP. Duration of anaesthesia and complete recovery were significantly (p&lt;0.05) longer in group DP as compared to group BP and AP. The physiological and haemodynamic parameters showed transient changes which were compensated and remained within normal range during the study period without producing any deleterious effect. Thus, propofol can be safely used as induction agent in dogs premedicated with either dexmedetomidine or butorphanol or acepromazine and does not produce any adverse effect on cardiopulmonary system. However, dexmedetomidine-propofol combination provided longer duration of anaesthesia in dogs as compared to other groups.

Electroencephalographic and cardiovascular changes associated with simultaneous propofol and ketamine constant rate of infusion anesthesia in dogs

Electroencephalographic and cardiovascular changes associated with simultaneous propofol and ketamine constant rate of infusion anesthesia in dogs

What is the best treatment for hypotension in healthy dogs during anaesthesia maintained with isoflurane?

Hypotension is a common and potentially life-threatening complication of general anaesthesia in dogs. Due to the combination of cardiovascular side effects of many anaesthetic, sedative and analgesic drugs used peri-operatively hypotension is frequently reported even in healthy dogs undergoing elective procedures. Several treatment options for hypotension have been advocated. Potential treatments include rapid administration of either crystalloid or colloid fluids; pharmacological treatments to increase cardiac output and/or systemic vascular resistance; or reduction in the delivery of the volatile anaesthetic agents. This critical appraisal considers the current evidence for which treatment is the best option for treating hypotension in healthy euvolemic dogs undergoing general anaesthesia maintained with isoflurane. Fourteen relevant studies were appraised, including 12 laboratory studies and two small clinical trials. One study demonstrated that reduction in the delivery of isoflurane may correct hypotension, but this treatment may not always be feasible. In general, rapid administration of fluids did not increase blood pressure and failed to correct hypotension. Synthetic colloids demonstrated some efficacy, but results were inconsistent between studies and large volumes may be required. Infusion of dopamine appears to be the most reliable pharmacological option consistently increasing blood pressure, cardiac output and correcting hypotension.

A novel electroencephalographic evaluation of noxious stimulation during isoflurane anesthesia in dogs.

In veterinary clinical medicine, evaluating the balance between nociception and antinociception presents a great challenge for anesthesiologists during canine surgeries. Heart rate (HR) and mean arterial pressure (MAP) are suitable indexes for monitoring noxious stimuli during anesthesia. Frontal electroencephalography (EEG) records, including processed parameters, are recommended for evaluating nociceptive balance in anesthetized unconscious human patients, which is unexplored in veterinary medicine. Therefore, the objective is to explore the response of processed EEG parameters to noxious stimulation and elucidate the impact of noxious stimulation on frontal cortical activity in dogs anesthetized with 1.5% isoflurane. Fourteen dogs were included and underwent frontal EEG monitoring, measuring the patient state index (PSI) and spectral edge frequency (SEF) before and after administering noxious stimulation using the towel clamp method on the tail of each 1.5% isoflurane-anesthetized dog. As the noxious stimulation was applied, there was a simultaneous increase in PSI, HR, and MAP, with PSI exhibiting a drastic response. SEF, especially on the left side, also increased with noxious stimulation. In EEG power spectral analysis, the delta band was decreased, and the alpha and beta bands showed an increase following noxious stimulation, with a more profound elevation of beta bands on the left side. This study suggests that noxious stimulation brings asymmetric frontal cortical arousal, changing brain activity by suppressing delta waves and augmenting alpha and beta waves. Consequently, PSI seems to be a potential indicator for detecting stimuli in canine isoflurane anesthesia.

Efficacy of propofol with sevoflurane to produce balanced anaesthesia in dogs

Efficacy of propofol with sevoflurane to produce balanced anaesthesia in dogs

Changes in the gas composition of umbilical cord blood of newborns after cesarean section using various protocols of general anesthesia in dogs

Cesarean section, being one of the most common operations in veterinary surgery, requires a special anesthetic protocol that provides adequate anesthesia for the mother and has minimal effect on puppies. The aim of the study was to evaluate the effect of various non-inhalation and inhaled anesthetics on newborn puppies during cesarean section, based on the analysis of cord blood gases. 3 groups of experimental animals were formed, which used one of the studied anesthetic protocols. In the first experimental group, propofol at a dose of 4-6 mg/kg was used to maintain general anesthesia. Inhaled halogen-containing anesthetics were used in the second and third experimental groups. Isoflurane 0.5 – 2.0 vol% was used in the second group, and sevoflurane 1.0 – 2.0 vol% was used in the third group. When using all the studied anesthetics, an acidbase imbalance in the form of moderate acidosis was detected in the puppies after delivery, however, acidosis was less pronounced in the groups where halogen-containing anesthetics were used. The use of inhaled halogen-containing anesthetics had a lesser effect on puppies compared to non-inhalation ones. There were no significant differences in the effect of isoflurane and sevoflurane from inhaled anesthetics.

A retrospective analysis of different doses of glycopyrrolate for treatment of bradycardia during anaesthesia in dogs: preliminary results

A retrospective analysis of different doses of glycopyrrolate for treatment of bradycardia during anaesthesia in dogs: preliminary results

Association between body mass and hypotension in dogs under general anaesthesia.

To investigate the association between body mass and hypotension during general anaesthesia in dogs undergoing surgical and diagnostic procedures within a referral hospital. Retrospective evaluation of the anaesthetic records of 1789 dogs was performed. Data on signalment, anaesthetic protocol and physiological variables, including mean arterial pressure, were collected. A multivariable generalised linear model was used to identify associations between explanatory variables, including body mass, and hypotension. In the population studied, increasing body mass (per 10 kg) was significantly associated with decreasing odds of hypotension (odds ratio 0.68; 95% confidence interval: 0.60 to 0.77). Additional variables associated with a decreased odds of hypotension were pre-anaesthetic medication with alpha-2 agonists (odds ratio 0.63; 95% confidence interval 0.48 to 0.82) and increasedbody temperature (per 1°C) during general anaesthesia (odds ratio 0.77; 95% confidence interval 0.67 to 0.88). Brachycephaly (odds ratio 1.72; 95% confidence interval 1.25 to 2.38), ASA physical status classification >3 (odds ratio 2.03; 95% confidence interval 1.16 to 3.56), undergoing a surgical procedure (versus diagnostic) (odds ratio 1.57; 95% confidence interval 1.10 to 2.23) and bradycardia (odds ratio 1.37; 95% confidence interval 1.05 to 1.80) were independently associated with increased odds of hypotension. Dogs of lower body mass and brachycephalic breeds may be at higher risk of hypotension during general anaesthesia or alternatively represent subpopulations in which accurate blood pressure measurement presents a greater challenge. Monitoring blood pressure accurately in these groups requires particular attention and provisions for treating hypotension should be readily accessible.