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Animals : An Open Access Journal From... Nov 2021Dexmedetomidine is commonly used in small animal anesthesia for its potent sedative and analgesic properties; however, concerns regarding its cardiovascular effects... (Review)
Review
Dexmedetomidine is commonly used in small animal anesthesia for its potent sedative and analgesic properties; however, concerns regarding its cardiovascular effects prevent its full adoption into veterinary clinical practice. This meta-analysis was to determine the effects of dexmedetomidine on sedation, analgesia, cardiovascular and adverse reactions in dogs compared to other premedications. Following the study protocol based on the Cochrane Review Methods, thirteen studies were included in this meta-analysis ultimately, involving a total of 576 dogs. Dexmedetomidine administration probably improved in sedation and analgesia in comparison to acepromazine, ketamine and lidocaine (MD: 1.96, 95% CI: [-0.08, 4.00], = 0.06; MD: -0.95, 95% CI: [-1.52, -0.37] = 0.001; respectively). Hemodynamic outcomes showed that dogs probably experienced lower heart rate and higher systolic arterial blood pressure and mean arterial blood pressure with dexmedetomidine at 30 min after premedication (MD: -13.25, 95% CI: [-19.67, -6.81], < 0.0001; MD: 7.78, 95% CI: [1.83, 13.74], = 0.01; MD: 8.32, 95% CI: [3.95, 12.70], = 0.0002; respectively). The incidence of adverse effects was comparable between dexmedetomidine and other premedications (RR = 0.86, 95% CI [0.58, 1.29], = 0.47). In summary, dexmedetomidine provides satisfactory sedative and analgesic effects, and its safety is proved despite its significant hemodynamic effects as part of balanced anesthesia of dogs.
PubMed: 34827988
DOI: 10.3390/ani11113254 -
Animals : An Open Access Journal From... Oct 2021The purpose of the current study was to investigate the effects of two commonly used sedation protocols in dogs, acepromazine (ACP) and acepromazine-methadone (ACP-MET)...
The purpose of the current study was to investigate the effects of two commonly used sedation protocols in dogs, acepromazine (ACP) and acepromazine-methadone (ACP-MET) combination, on tear production measured by the Schirmer Tear Test (STT) 1. We hypothesized that both sedation protocols cause a reduction in canine tear production for a variable time. Fifteen client-owned dogs were recruited for the study. Each dog was subjected to sedation twice, 2-3 weeks apart, and they were randomly allocated to one of two groups receiving ACP (0.015 mg kg) or ACP-MET (0.010 mg kg and 0.2 mg kg) intramuscularly. In both eyes, tear production was measured 15 min before sedation (T0) and 20 min (T20 m), 40 min (T40 m), 1 h (T1), 2 h (T2), 4 h (T4) and 8 h (T8), after drug administration. Two-way repeated measures ANOVA, followed by the Bonferroni post hoc test ( < 0.05), showed a significant effect of time ( < 0.0001) and treatment ( < 0.0001). A significant decrease in tear production at T20 m, T40 m, T1 and T2 compared to T0 was observed in the ACP experimental protocol, while in the ACP + MET protocol, this reduction persisted until T8. Comparing the two experimental protocols, no statistically significant differences were observed at T0 or T20 m, and STT 1 values were statistically lower in the ACP + MET than the ACP protocol at the other data points. In the ACP + MET group, at T40 m, 100% of dogs showed STT 1 readings lower than 15 mm/min. This finding is clinically relevant as it can predispose dogs to corneal injuries. The major reduction in tear production due to the ACP + MET protocol proves the need for adequate corneal hydration, particularly to discourage its use in animals with altered tear production. The data obtained provide important information helping clinicians to better manage the drug's effects on tear production.
PubMed: 34827748
DOI: 10.3390/ani11113015 -
Veterinary Medicine and Science Jan 2022The present prospective randomized experimental study was designed to assess pain control with intraperitoneal morphine following ovariohysterectomy in dogs. A group of...
The present prospective randomized experimental study was designed to assess pain control with intraperitoneal morphine following ovariohysterectomy in dogs. A group of 12 mixed breed female dogs, aged 1-2 years, weighing 19.95 ± 0.95 kg were included. Forty minutes after sedation with 0.05 mg/kg intramuscular acepromazine 1%, anaesthesia was induced with propofol (4 mg/kg). The dogs were connected to the inhalation anaesthesia circuit using isoflurane. Ovariohysterectomy was performed, and before the closure of linea alba, the animals received intraperitoneal morphine (0.5 mg/kg) (in group M) and saline (0.2 ml/kg) (in group S). No significant difference was detected in total protein and glucose levels between the groups, while the cortisol level in group M was significantly lower than group S 1, 3 and 6 h after surgery. Furthermore, the comparison of the rectal temperature, heart rates and respiratory rates showed no major differences. Additionally, no significant alterations were detected between the groups considering the changes in the pain scores with simple descriptive score, Glasgow, University of Melbourne pain scale, sedation status and Sammarco methods. Finally, three cases in group S and two cases in group M were given an intramuscular analgesic rescue dose of morphine. Although a significant decline was observed in cortisol levels following intraperitoneal morphine administration, there were no beneficial changes in the efficiency of post-operative analgesia in status and clinical signs compared to the control group. Further studies are required to investigate intraperitoneal morphine effectiveness in post-operative pain management.
Topics: Animals; Dog Diseases; Dogs; Female; Hysterectomy; Morphine; Ovariectomy; Pain, Postoperative; Prospective Studies
PubMed: 34821072
DOI: 10.1002/vms3.668 -
Frontiers in Veterinary Science 2021Sedatives and tranquilizers are important in the control of excited camels during camel transport. This study was conducted to investigate the clinical sedation of...
Sedatives and tranquilizers are important in the control of excited camels during camel transport. This study was conducted to investigate the clinical sedation of camels with acepromazine and its correlation with pharmacokinetics and pharmacodynamics. The sedation score, heart rate, respiration, body temperature, and pharmacokinetics were monitored before and after acepromazine injection, and myeloid marker expression was analyzed using membrane immunofluorescence and flow cytometry. The distribution (t1/2α) and elimination (t1/2β) half-lives were 0.1 and 9.4 h, respectively. The volume of distribution at steady state (Vss) was 20.01 L/kg, and the mean residence time (MRT) was 12.25 h. Sedation started rapidly within 10 min followed by persistent low-medium sedation for 2 h with an average sedation score of 1.2 ± 0.61, which might be associated with a slow elimination phase and prolonged MRT. Compared to horses, camels showed a lower clearance rate, higher volume of distribution, and higher elimination half-life. Slight changes in body temperature and heart and respiratory rate, as well as a lower hematocrit and changes in blood cell composition, suggest the careful application of acepromazine in animals with abnormal blood parameters or poor vital conditions.
PubMed: 34568476
DOI: 10.3389/fvets.2021.725841 -
Animals : An Open Access Journal From... Aug 2021The purpose of this study was to determine the analgesic efficacy and safety of epidural lidocaine-xylazine administration in standing mules undergoing elective...
The purpose of this study was to determine the analgesic efficacy and safety of epidural lidocaine-xylazine administration in standing mules undergoing elective bilateral laparoscopic ovariectomy in order to suppress unwanted behaviour. Eight mule mares were sedated with intramuscular 0.05 mg/kg acepromazine followed by 1.3 mg/kg of xylazine and 0.02 mg/kg of butorphanol intravenously. Sedation was maintained by a constant rate infusion of 0.6 mg/kg/h of xylazine. The paralumbar fossae were infiltrated with 30 mL of 2% lidocaine. Epidural anaesthesia was performed at the first intercoccygeal space with 0.2 mg/kg of lidocaine and 0.17 mg/kg of xylazine. After 15 min, bilateral laparoscopic ovariectomy was performed. Heart rate, respiratory rate, rectal temperature, invasive arterial blood pressure, degree of analgesia, sedation and ataxia were evaluated during surgery. The laparoscopic ovariectomy was successfully completed in all animals. Sedation and analgesia were considered satisfactory in six out of the eight mules. In conclusion, caudal epidural block allowed surgery to be easily completed in six out of eight. The animals did not show any signs of discomfort associated with nociception and were mostly calm during the procedures, however additional studies are needed to establish epidural doses of xylazine and lidocaine that result in reliable abdominal pain control in mules for standing ovariectomy.
PubMed: 34438877
DOI: 10.3390/ani11082419 -
Veterinary Sciences Jul 2021To evaluate the use of ketamine-medetomidine-midazolam total intravenous infusion as part of a balanced anaesthetic technique for surgical castration in horses. Five...
To evaluate the use of ketamine-medetomidine-midazolam total intravenous infusion as part of a balanced anaesthetic technique for surgical castration in horses. Five healthy Standardbred cross colts were premedicated with IV acepromazine (0.01-0.02 mg/kg), medetomidine (7 µg/kg) and methadone (0.1 mg/kg) and anaesthesia induced with IV ketamine (2.2 mg/kg) and midazolam (0.06 mg/kg). Horses were anaesthetised for 40 min with an IV infusion of ketamine (3 mg/kg/h), medetomidine (5 µg/kg/h) and midazolam (0.1 mg/kg/h) while routine surgical castration was performed. Cardiorespiratory variables, arterial blood gases, and anaesthetic depth were assessed at 5 to 10 min intervals. Post-anaesthesia recovery times were recorded, and the quality of the recovery period was assessed. The anaesthetic period and surgical conditions were acceptable with good muscle relaxation and no additional anaesthetic required. The median (range) time from cessation of the infusion to endotracheal tube extubation, head lift and sternal recumbency were 17.2 (7-35) min, 25 (18.9-53) min and 28.1 (23-54) min, respectively. The quality of anaesthetic recovery was good, with horses standing 31.9 (28-61) min after the infusion was ceased. During anaesthesia, physiological variables, presented as a range of median values for each time point were: heart rate 37-44 beats/min, mean arterial pressure 107-119 mmHg, respiratory rate 6-13 breaths/min, arterial partial pressure of oxygen 88-126 mmHg, arterial partial pressure of carbon dioxide 52-57 mmHg and pH 7.36-7.39. In conclusion, the co-administration of midazolam, ketamine and medetomidine as in IV infusion, when used as part of a balanced anaesthetic technique, was suitable for short term anaesthesia in horses undergoing castration.
PubMed: 34437464
DOI: 10.3390/vetsci8080142 -
American Journal of Veterinary Research Sep 2021To investigate whether premedication with hydromorphone alone or combined with acepromazine or dexmedetomidine affects the incidence of gastroesophageal reflux (GER) and...
Randomized, blinded, controlled clinical trial to assess gastroesophageal reflux and regurgitation in dogs undergoing general anesthesia after hydromorphone premedication with or without acepromazine or dexmedetomidine.
OBJECTIVE
To investigate whether premedication with hydromorphone alone or combined with acepromazine or dexmedetomidine affects the incidence of gastroesophageal reflux (GER) and regurgitation in dogs undergoing general anesthesia for elective orthopedic surgery.
ANIMALS
39 healthy client-owned dogs undergoing general anesthesia for elective orthopedic surgery between November 2016 and November 2018.
PROCEDURES
For this prospective, randomized, controlled, blinded clinical trial, dogs were randomly assigned to be premedicated with hydromorphone (0.1 mg/kg, IM) alone (group H [control group]) or with either acepromazine (0.05 mg/kg, IM; group AH) or dexmedetomidine (6 μg/kg, IM; group DH) before undergoing general anesthesia induced with propofol and maintained with isoflurane. A pH sensor-tipped probe was used to identify episodes of GER (esophageal pH < 4 or > 7.5 for ≥ 30 seconds). Results for GER, regurgitation, vomiting, propofol dose, and durations of food withholding and anesthesia were compiled and compared across groups.
RESULTS
There were 13 dogs in each group, and no meaningful differences were detected in age, body weight, sex, breed, or durations of anesthesia or food withholding across groups. Overall, 16 of the 39 (41%) dogs developed GER: 9 in group H, 6 in group AH, and 1 in group DH. The incidence of GER was significantly lower for group DH versus group H. Six of the 39 (15%) dogs regurgitated: 4 in group H and 2 in group AH.
CONCLUSIONS AND CLINICAL RELEVANCE
The combined use of dexmedetomidine and hydromorphone as premedication may be a better choice to reduce GER in healthy dogs undergoing orthopedic surgery than would the use of hydromorphone with or without acepromazine. Additional research is warranted.
Topics: Acepromazine; Anesthesia, General; Animals; Dexmedetomidine; Dog Diseases; Dogs; Gastroesophageal Reflux; Hydromorphone; Premedication; Prospective Studies; Vomiting
PubMed: 34432514
DOI: 10.2460/ajvr.82.9.695 -
PloS One 2021Although facial characteristics are used to estimate horse sedation, there are no studies measuring their reliability and validity. This randomised controlled,...
Although facial characteristics are used to estimate horse sedation, there are no studies measuring their reliability and validity. This randomised controlled, prospective, horizontal study aimed to validate a facial sedation scale for horses (FaceSed). Seven horses received detomidine infusion i.v. in low or high doses/rates alone (DL 2.5 μg/kg+6.25 μg/kg/h; DH 5 μg/kg+12.5 μg/kg/h) or combined with methadone (DLM and DHM, 0.2 mg/kg+0.05 mg/kg/h) for 120 min, or acepromazine boli i.v. in low (ACPL 0.02 mg/kg) or high doses (ACPH 0.09 mg/kg). Horses' faces were photographed at i) baseline, ii) peak, iii) intermediate, and iv) end of sedation. After randomisation of moments and treatments, photos were sent to four evaluators to assess the FaceSed items (ear position, orbital opening, relaxation of the lower and upper lip) twice, within a one-month interval. The intraclass correlation coefficient of intra- and interobserver reliability of FaceSed scores were good to very good (0.74-0.94) and moderate to very good (0.57-0.87), respectively. Criterion validity based on Spearman correlation between the FaceSed versus the numerical rating scale and head height above the ground were 0.92 and -0.75, respectively. All items and the FaceSed total score showed responsiveness (construct validity). According to the principal component analysis all FaceSed items had load factors >0.50 at the first dimension. The high internal consistency (Cronbach´s α = 0.83) indicated good intercorrelation among items. Item-total Spearman correlation was adequate (rho 0.3-0.73), indicating homogeneity of the scale. All items showed sensitivity (0.82-0.97) to detect sedation, however only orbital opening (0.79) and upper lip relaxation (0.82) were specific to detect absence of sedation. The limitations were that the facial expression was performed using photos, which do not represent the facial movement and the horses were docile, which may have reduced specificity. The FaceSed is a valid and reliable tool to assess tranquilisation and sedation in horses.
Topics: Anesthesia; Animals; Horses; Male
PubMed: 34061878
DOI: 10.1371/journal.pone.0251909 -
Acta Veterinaria Scandinavica May 2021Cryptorchidism in dogs is of clinical concern due to its association with development of Sertoli cell tumours, seminomas and spermatic cord torsion. A patent inguinal...
BACKGROUND
Cryptorchidism in dogs is of clinical concern due to its association with development of Sertoli cell tumours, seminomas and spermatic cord torsion. A patent inguinal ring has been found as a risk factor for peritoneal content migration and inguinal hernias. This study reports a case of bowel migration through a patent inguinal ring in a bilaterally cryptorchid dog and incarceration within the vaginal tunic of the left testicle.
CASE PRESENTATION
A three-and-a-half-year-old bilaterally cryptorchid Lhasa Apso with a history of anorexia, vomiting, stranguria and inability to defecate was diagnosed with bowel incarceration in the vaginal tunic of a retained left testicle. Surgery performed under epidural anaesthesia with acepromazine/butorphanol premedication revealed a loop of the colon entrapped in the vaginal tunic of the retained left testicle. The incarcerated bowel was thoroughly examined for viability and repositioned into the abdominal cavity. The inguinal ring was repaired and bilateral cryptorchidectomy performed.
CONCLUSION
Cryptorchidectomy in dogs is often considered when there is concern for neoplasm or torsion of retained testes. However, this report suggests that cryptorchidectomy should be considered also to preclude the possibility of bowel obstructive emergencies.
Topics: Animals; Cryptorchidism; Diagnosis, Differential; Dog Diseases; Dogs; Hernia, Inguinal; Intestinal Obstruction; Male; Spermatic Cord Torsion; Vomiting
PubMed: 34011368
DOI: 10.1186/s13028-021-00586-y -
Journal of the American Association For... May 2021Oxygen supplementation is rarely considered when anesthetizing laboratory mice, despite reports that mice become profoundly hypoxic under anesthesia. Little is known...
Oxygen supplementation is rarely considered when anesthetizing laboratory mice, despite reports that mice become profoundly hypoxic under anesthesia. Little is known about the effects of hypoxia on anesthetic performance. This article focuses on the effects of oxygen supplementation on physiologic parameters and depth of anesthesia in male and female C57BL/6 mice. Anesthesia was performed via common injectable anesthetic protocols and with isoflurane. Mice anesthetized with injectable anesthesia received one of 3 drug protocols. Low-dose ketamine/xylazine (100/8 mg/kg) was chosen to provide immobilization of mice, suitable for imaging procedures. Medium-dose ketamine/xylazine/acepromazine (100/10/1 mg/kg) was chosen as a dose that has been recommended for surgical procedures. High-dose ketamine/xylazine/acepromazine (150/12/3 mg/kg) was chosen after pilot studies to provide a long duration of a deep plane of anesthesia. We also tested the effects of oxygen supplementation on the minimum alveolar concentration (MAC) of isoflurane in mice. Mice breathed supplemental 100% oxygen, room air, or medical air with 21% oxygen. Anesthetized mice that did not receive supplemental oxygen all became hypoxic, while hypoxia was prevented in mice that received oxygen. Oxygen supplementation did not affect the MAC of isoflurane. At the high injectable dose, all mice not receiving oxygen supplementation died while all mice receiving oxygen supplementation survived. At low and medium doses, supplemental oxygen reduced the duration of the surgical plane of anesthesia (low dose with oxygen: 22 ± 14 min; low dose without supplementation: 29 ± 18 min; medium dose with oxygen: 43 ± 18 min; medium dose without supplementation: 61 ± 27 min). These results suggest that mice anesthetized with injectable and inhalant anesthesia without supplemental oxygen are routinely hypoxic. This hypoxia prolongs the duration of anesthesia with injectable drug protocols and affects survival at high doses of injectable anesthetics. Because of variable responses to injectable anesthetics in mice, oxygen supplementation is recommended for all anesthetized mice.
Topics: Anesthesia; Animals; Female; Isoflurane; Male; Mice; Mice, Inbred C57BL; Oxygen; Oxygen Inhalation Therapy; Xylazine
PubMed: 33972009
DOI: 10.30802/AALAS-JAALAS-20-000143