Effects of Medetomidine, Dexmedetomidine and their combination with Acepromazine on the intraocular pressure (IOP), tear secretion and pupil diameter in dogs.

BACKGROUND: A great number of sedatives and anaesthetics have been used to perform surgeries or routine ophthalmologic examinations in animals and sometimes the combination of these medicines has more suitable effects than each one alone. OBJECTIVES: This paper aims to explore the main effects of Medetomidine + Acepromazine, Dexmedetomidine + Acepromazine on intraocular pressure, tear secretion and pupil diameter. METHODS: To accomplish the aforementioned aim, 32 adult dogs (aged one-to-three-years-old) were clinically examined. Dogs were divided into four groups consisting of group DA, Dexmedetomidine (5 µg/kg) + Acepromazine (0.05 mg/kg); Group D, Dexmedetomidine (5 µg/kg); Group M, Medetomidine (10 µg/kg); Group MA, Medetomidine (10 µg/kg) + Acepromazine (0.05 mg/kg). The ocular factors including tear production, pupil diameter and intraocular pressure of both right and left eyes were first measured and then recorded in each dog at time T0 (-15 min). Afterwards, the drugs were administered intramuscularly, based on which the ocular factors were re-measured at T1 (+5 min), T2 (+15 min) and T3 (+20 min). All four groups showed a reduction in intraocular pressure, which was significant in DA, D and M groups. RESULTS: Furthermore, there was a fluctuation in the amount of tear secretion in DA and D groups (increase and then decrease), as well as a significant reduction in M and MA groups. Decreasing in pupil diameter also occurred in all four groups, but the reduction was significant only in DA and MA groups. CONCLUSION: According to the results obtained, as the changes caused by the systemic administration of the above drug compounds did not exceed the physiological range, it can be concluded that these combinations could be utilized as suitable sedatives or pre-anaesthetic compounds in the eye surgeries.

Quantitative Structure-Activity Relationship (QSAR) Model for the Severity Prediction of Drug-Induced Rhabdomyolysis by Using Random Forest.

Drug-induced rhabdomyolysis (DIR) is a rare and potentially life-threatening muscle injury that is characterized by low incidence and high risk. To our best knowledge, the performance of the current predictive models for the early detection of DIR is suboptimal because of the scarcity and dispersion of DIR cases. Therefore, on the basis of the curated drug information from the Drug-Induced Rhabdomyolysis Atlas (DIRA) database, we proposed a random forest (RF) model to predict the DIR severity of the marketed drugs. Compared with the state-of-art methods, our proposed model outperformed extreme gradient boosting, support vector machine, and logistic regression in distinguishing the Most-DIR concern drugs from the No-DIR concern drugs (Matthews correlation coefficient (MCC) and recall rate of our model were 0.46 and 0.81, respectively). Our model was subsequently applied to predicting the potentially serious DIR for 1402 drugs, which were reported to cause DIR by the postmarketing DIR surveillance data in the FDA Spontaneous Adverse Events Reporting System (FAERS). As a result, 62.7% (94) of drugs ranked in the top 150 drugs with the Most-DIR concerns in FAERS can be identified by our model. The top four drugs (odds ratio >30) including acepromazine, rapacuronium, oxyphenbutazone, and naringenin were correctly predicted by our model. In conclusion, the RF model can well predict the Most-DIR concern drug only based on the chemical structure information and can be a facilitated tool for early DIR detection.

The effect of intravenous maropitant on blood pressure in healthy awake and anesthetized dogs.

OBJECTIVE: To evaluate the effects of intravenous maropitant on arterial blood pressure in healthy dogs while awake and under general anesthesia. DESIGN: Experimental crossover study. ANIMALS: Eight healthy adult Beagle dogs. PROCEDURE: All dogs received maropitant (1 mg kg-1) intravenously under the following conditions: 1) awake with non-invasive blood pressure monitoring (AwNIBP), 2) awake with invasive blood pressure monitoring (AwIBP), 3) premedication with acepromazine (0.005 mg kg-1) and butorphanol (0.2 mg kg-1) intramuscularly followed by propofol induction and isoflurane anesthesia (GaAB), and 4) premedication with dexmedetomidine (0.005 mg kg-1) and butorphanol (0.2 mg kg-1) intramuscularly followed by propofol induction and isoflurane anesthesia (GaDB). Heart rate (HR), systolic (SAP), diastolic (DAP), and mean blood pressures (MAP) were recorded before injection of maropitant (baseline), during the first 60 seconds of injection, during the second 60 seconds of injection, at the completion of injection and every 2 minutes post injection for 18 minutes. The data were compared over time using a Generalized Linear Model with mixed effects and then with simple effect comparison with Bonferroni adjustments (p <0.05). RESULTS: There were significant decreases from baseline in SAP in the GaAB group (p < 0.01) and in MAP and DAP in the AwIBP and GaAB (p < 0.001) groups during injection. A significant decrease in SAP (p < 0.05), DAP (p < 0.05), and MAP (p < 0.05) occurred at 16 minutes post injection in GaDB group. There was also a significant increase in HR in the AwIBP group (p < 0.01) during injection. Clinically significant hypotension occurred in the GaAB group with a mean MAP at 54 ± 6 mmHg during injection. CONCLUSION: Intravenous maropitant administration significantly decreases arterial blood pressure during inhalant anesthesia. Patients premedicated with acepromazine prior to isoflurane anesthesia may develop clinically significant hypotension.

A comparative study of the cardiopulmonary and sedative effects of a single intramuscular dose of ketamine anesthetic combinations in rabbits.

The aim of this prospective, randomized, blinded crossover study was compare the cardiopulmonary and sedative effects of ketamine in combination with acepromazine, diazepam, dexmedetomidine, midazolam or xylazine, injected intramuscularly in rabbits, using eight one-year-old male New Zealand rabbits (4.1 ± 0.40 kg). All treatments included ketamine (K; 30 mg/kg) in combination with one of the following: acepromazine 0.5 mg/kg (treatment KA); diazepam 1 mg/kg (KD); dexmedetomidine 0.025 mg/kg (KDex); midazolam 1 mg/kg (KM); or xylazine 3 mg/kg (KX) mixed in the same syringe and injected intramuscularly. Cardiopulmonary variables, blood gases and sedative scores were measured before injection (T0 or baseline) and every 10 min thereafter, over a 60-min period. There were reductions in heart rate, compared with the baseline, at all evaluation times in treatment KX. Treatments KDex, KM and KX presented reductions in respiratory rate at all evaluation times, in comparison with the baseline. There were reductions in mean arterial pressure in KA and KX at times T10-T60 and in PaO2 in KDex, KM and KX at T10-T50. The sedation scores were similar in KA, KDex, KM and KX at T10-T20. Ketamine in combination with acepromazine, dexmedetomidine, midazolam or xylazine promoted similar sedative effects for twenty minutes, but the α2-agonists can promote hypoxemia.

Postinduction apnoea in dogs premedicated with acepromazine or dexmedetomidine and anaesthetized with alfaxalone or propofol.

OBJECTIVE: To compare incidence and duration of postinduction apnoea in dogs after premedication with methadone and acepromazine (MA) or methadone and dexmedetomidine (MD) followed by induction with propofol (P) or alfaxalone (A). STUDY DESIGN: Prospective, randomized clinical trial. ANIMALS: A total of 32 American Society of Anesthesiologists class I dogs (15 females, 17 males), aged between 4 months and 4 years, weighing between 3 and 46 kg. METHODS: Dogs were randomly allocated to be administered MA+P, MA+A, MD+P or MD+A (methadone 0.5 mg kg-1 and acepromazine 0.05 mg kg-1 or dexmedetomidine 5 µg kg-1). Induction agents were administered intravenously via syringe driver (P at 4 mg kg-1 minute-1 or A at 2 mg kg-1 minute-1) until successful endotracheal intubation and the endotracheal tube connected to a circle system with oxygen flow at 2 L minute-1. Oxygen saturation of haemoglobin (SpO2), end tidal partial pressure of carbon dioxide and respiratory rate were monitored continuously. If apnoea (≥ 30 seconds without breathing) occurred, the duration until first spontaneous breath was measured. If SpO2 decreased below 90% the experiment was stopped and manual ventilation initiated. Data were analysed with general linear models with significance set at p ≤ 0.05. RESULTS: There was no statistical difference in the incidence (11 of 16 dogs in A groups and 12 of 16 dogs in P groups), or mean ± standard deviation duration (A groups 125 ± 113 seconds, P groups 119 ± 109 seconds) of apnoea. The SpO2 of one dog in the MD+P group decreased below 90% during the apnoeic period. CONCLUSIONS AND CLINICAL RELEVANCE: Propofol and alfaxalone both cause postinduction apnoea and the incidence and duration of apnoea is not influenced by the use of acepromazine or dexmedetomidine in premedication. Monitoring of respiration is recommended when using these premedication and induction agent combinations.

Hematological and splenic Doppler ultrasonographic changes in dogs sedated with acepromazine or xylazine.

OBJECTIVE: To evaluate the onset and duration of hematological changes and the use of Doppler ultrasound (spleen) in dogs sedated with acepromazine or xylazine. STUDY DESIGN: Clinical study. ANIMALS: A total of 24 mixed breed dogs aged 1-4 years and weighing 15-25 kg. METHODS: Dogs were randomly distributed into two groups: acepromazine group (AG) which were administered acepromazine (0.05 mg kg-1) intramuscularly and xylazine group (XG) administered xylazine (0.5 mg kg-1) intramuscularly. Sonographic evaluations (morphologic and hemodynamic splenic vascularization) and hematologic tests were performed before drug administration (baseline) and 5, 15, 30, 60, 120, 240, 360, 480 and 720 minutes after drug administration. RESULTS: A significant reduction occurred in erythrogram variables in AG at 15-720 minutes corresponding with a significant enlargement of the spleen. In XG, a significant reduction was observed in the erythrogram variables at 30-60 minutes without a significant enlargement of the spleen. Hilar diameter did not change over time in either group. Flow alterations were found only in the splenic artery in AG, with a decreased final diastolic velocity observed at 60-120 minutes. CONCLUSIONS: Administration of acepromazine resulted in decreased red blood cell count, hemoglobin, packed cell volume and an increased diameter of the spleen. Xylazine administration resulted in similar hematologic changes but of smaller magnitude and duration and without splenic changes. The absence of significant changes in the Doppler flow parameters of the splenic artery and vein and the hilar diameter suggests that the splenomegaly that was observed in AG was not due to splenic vasodilation. No splenic sequestration occurred after xylazine administration. CLINICAL RELEVANCE: The results indicate that acepromazine decreases the erythrocyte concentrations by splenic erythrocyte sequestration and concomitant splenomegaly. Xylazine can cause slight hematologic changes, but without splenic changes.

The effects of acupuncture point Pericardium 6 on hydromorphone-induced nausea and vomiting in healthy dogs.

OBJECTIVE: To evaluate the effect of needling at acupuncture point Pericardium 6 on hydromorphone-induced nausea and vomiting. STUDY DESIGN: Randomized controlled clinical study. ANIMALS: Eighty-one mixed-breed, healthy dogs aged 1.8 ± 1.6 years and weighing 14.5 ± 5.6 kg, admitted for elective ovariohysterectomy (n = 75) or castration (n = 6). METHODS: Dogs were randomly assigned to one of three groups: acupuncture at Pericardium 6 (AT, n = 27); alternative acupuncture at Lung 5 (ST, n = 27), and no acupuncture (CT, n = 27). During time 0-30 minutes (baseline), occurrences of hypersalivation, vomiting and licking were recorded. At 30 minutes, subjects were administered hydromorphone (0.1 mg kg(-1) ) in combination with acepromazine (0.03 mg kg(-1) ) intramuscularly. During time 30-45 minutes (post-injection), occurrences of hypersalivation, vomiting and licking were recorded by an observer unaware of group assignment. Groups were compared using a Kruskal-Wallis test followed by a Dunn's post-test, or Fisher's exact tests when appropriate. RESULTS: There were no significant differences in age, weight or baseline observations among groups. Vomiting incidence post-injection was higher in the CT (20/27, 74.1%) and ST (22/27, 81.5%) groups than in the AT (10/27, 37.0%) group (p = 0.0129 and p = 0.002, respectively). The number of vomiting episodes [median (range)] after opioid administration was higher in the ST [1 (1-6)] than the AT [0 (0-2)] group (p = 0.0040). There were no differences in the median number of vomiting episodes between the ST and CT [1 (0-3)] or AT and CT groups. There were no differences in hypersalivation or licking among groups after hydromorphone-acepromazine administration. CONCLUSIONS AND CLINICAL RELEVANCE: Pericardium 6 acupuncture reduced the incidence of hydromorphone-induced vomiting in healthy dogs. This cost-effective technique can improve patient well-being and comfort during the perioperative period.

Comparison of the cardiorespiratory effects of a combination of ketamine and propofol, propofol alone, or a combination of ketamine and diazepam before and after induction of anesthesia in dogs sedated with acepromazine and oxymorphone.

OBJECTIVE: To evaluate the cardiorespiratory effects of IV administration of propofol (4 mg/kg), ketamine hydrochloride and propofol (2 mg/kg each; K-P), or ketamine hydrochloride (5 mg/kg) and diazepam (0.2 mg/kg; K-D) before and after induction of anesthesia (IoA) in dogs sedated with acepromazine maleate and oxymorphone hydrochloride. ANIMALS: 10 healthy adult Beagles. PROCEDURES: Each dog was randomly allocated to receive 2 of 3 treatments (1-week interval). For instrumentation prior to each treatment, each dog was anesthetized with isoflurane. After full recovery, acepromazine (0.02 mg/kg) and oxymorphone (0.05 mg/kg) were administered IV. Fifteen minutes later (before IoA), each dog received treatment IV with propofol, K-P, or K-D. Cardiorespiratory and arterial blood gas variables were assessed before, immediately after, and 5 minutes after IoA. RESULTS: Compared with findings before IoA, dogs receiving the K-P or K-D treatment had increased cardiac output, oxygen delivery, and heart rate 5 minutes after IoA; K-P administration did not change mean arterial blood pressure or stroke volume and decreased systemic vascular resistance. Propofol decreased mean arterial blood pressure and systemic vascular resistance immediately after IoA but did not change heart rate, cardiac output, or oxygen delivery. All treatments caused some degree of apnea, hypoventilation, and hypoxemia (Pao2 < 80 mm Hg). CONCLUSIONS AND CLINICAL RELEVANCE: In dogs, K-P treatment maintained mean arterial blood pressure better than propofol alone and increased heart rate, cardiac output, or oxygen delivery, as did the K-D treatment. Supplemental 100% oxygen should be provided during IoA with all 3 treatments.

Maropitant prevented vomiting but not gastroesophageal reflux in anesthetized dogs premedicated with acepromazine-hydromorphone.

OBJECTIVE: To evaluate the efficacy of maropitant for prevention of vomiting and gastroesophageal reflux (GER) in dogs following acepromazine-hydromorphone premedication and inhalation anesthesia. STUDY DESIGN: Randomized, blinded, prospective clinical study. ANIMALS: Twenty-six dogs admitted for elective soft tissue or orthopedic procedures that were 3.1 ±3.1 years of age and weighed 20.5 ± 11.4 kg. METHODS: Dogs were randomly assigned to one of two groups: Group M received maropitant (1.0 mg kg(-1) ) and Group S received 0.9% saline (0.1 mL kg(-1) ) intravenously 45-60 minutes before premedication with hydromorphone (0.1 mg kg(-1) ) and acepromazine (0.03 mg kg(-1) ) intramuscularly. An observer blinded to treatment documented any retching or vomiting for 20 minutes before induction with propofol (2-6 mg kg(-1) ) and inhalation anesthesia. A pH probe inserted into the distal esophagus was used to detect GER. RESULTS: None of the dogs in Group M retched or vomited (0/13), 6/13 (46%) in Group S were observed to retch or vomit, and the difference between groups was significant (p = 0.015). There were no differences between groups in the number of dogs with GER (Group M: 4/13, Group S: 6/13 dogs) or the number of reflux events. Esophageal pH at the end of anesthesia was significantly lower in both M and S groups in dogs with GER versus dogs without GER (p = 0.004 and 0.011, respectively). Only dogs with GER in Group S had significantly lower pH at the end compared to the beginning of anesthesia (p = 0.004). CONCLUSIONS AND CLINICAL RELEVANCE: Intravenous maropitant prevented retching and vomiting associated with acepromazine-hydromorphone premedication. Maropitant did not prevent the occurrence of GER. Fewer dogs in Group M developed GER but further study with a larger number of dogs is necessary to determine if there is a significant difference.

[Vigilance for veterinary medicinal products: reports of adverse reactions in the year 2012]. / Vigilance der Tierarzneimittel: Gemeldete unerwünschte Wirkungen im Jahr 2012.

197 adverse reactions of Swissmedic-authorized veterinary medicinal products were reported during the year 2012 (2011: 167). Species and drug classes remain unchanged over the years: most of the reports related to reactions following the use of antiparasitic products (37.6 %), antiinfectives (15.7 %) or non-steroidal antiinflammatory drugs (11.7 %) in companion animals (94 dogs and 53 cats) followed by cattle/calves (29). Additionally, 45 cases transmitted by the Swiss Toxicological Information Centre in Zürich were processed. We discuss a paradoxical reaction under the potential influence of acepromazine as well as a modified protocol for treating permethrin intoxication in cats. Finally, the vaccinovigilance program received 95 declarations following the application of various vaccines, mainly to dogs or cats.

En 2012, on a enregistré 197 annonces de réactions après application de médicaments vétérinaires autorisés par Swissmedic (2011: 167). La répartition de ces annonces, tant en ce qui concerne les espèces que les classes de médicaments, est inchangée par rapport aux années précédentes: on a annoncé le plus souvent des réactions à des produits antiparasitaires (37.6 %), antiinfectieux (15.7 %) ou antiinflammatoires (11.7 %) chez les petits animaux (94 annonces concernaient des chiens, 53 des chats) suivis par les bovins (29 annonces). En outre 45 cas annoncés par le Centre suisse d'information toxicologique de Zürich dans le cadre de ses activités de conseil ont été étudiés. Une réaction paradoxale d'agressivité sous l'effet possible de l'acépromazine et un protocole modifié pour le traitement des intoxications à la perméthrine chez le chat sont présentés. Pour ce qui est de la vaccinovigilance effectuée par l'IVI, on a enregistré 95 annonces de réactions après l'application de divers vaccins, principalement chez des chiens et des chats.

Alfaxalone for total intravenous anaesthesia in dogs undergoing ovariohysterectomy: a comparison of premedication with acepromazine or dexmedetomidine.

OBJECTIVE: To describe alfaxalone total intravenous anaesthesia (TIVA) following premedication with buprenorphine and either acepromazine (ACP) or dexmedetomidine (DEX) in bitches undergoing ovariohysterectomy. STUDY DESIGN: Prospective, randomised, clinical study. ANIMALS: Thirty-eight healthy female dogs. METHODS: Following intramuscular buprenorphine (20 µg kg(-1) ) and acepromazine (0.05 mg kg(-1) ) or dexmedetomidine (approximately 10 µg kg(-1) , adjusted for body surface area), anaesthesia was induced and maintained with intravenous alfaxalone. Oxygen was administered via a suitable anaesthetic circuit. Alfaxalone infusion rate (initially 0.07 mg kg(-1) minute(-1) ) was adjusted to maintain adequate anaesthetic depth based on clinical assessment. Alfaxalone boluses were given if required. Ventilation was assisted if necessary. Alfaxalone dose and physiologic parameters were recorded every 5 minutes. Depth of sedation after premedication, induction quality and recovery duration and quality were scored. A Student's t-test, Mann-Whitney U and Chi-squared tests determined the significance of differences between groups. Data are presented as mean ± SD or median (range). Significance was defined as p < 0.05. RESULTS: There were no differences between groups in demographics; induction quality; induction (1.5 ± 0.57 mg kg(-1) ) and total bolus doses [1.2 (0 - 6.3) mg kg(-1) ] of alfaxalone; anaesthesia duration (131 ± 18 minutes); or time to extubation [16.6 (3-50) minutes]. DEX dogs were more sedated than ACP dogs. Alfaxalone infusion rate was significantly lower in DEX [0.08 (0.06-0.19) mg kg(-1) minute(-1) ] than ACP dogs [0.11 (0.07-0.33) mg kg(-1) minute(-1) ]. Cardiovascular variables increased significantly during ovarian and cervical ligation and wound closure compared to baseline values in both groups. Apnoea and hypoventilation were common and not significantly different between groups. Arterial haemoglobin oxygen saturation remained above 95% in all animals. Recovery quality scores were significantly poorer for DEX than for ACP dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Alfaxalone TIVA is an effective anaesthetic for surgical procedures but, in the protocol of this study, causes respiratory depression at infusion rates required for surgery.

Effects of acepromazine maleate on platelet function assessed by use of adenosine diphosphate activated- and arachidonic acid- activated modified thromboelastography in healthy dogs.

OBJECTIVE: To evaluate the effect of acepromazine maleate administered IV on platelet function assessed in healthy dogs by use of a modified thromboelastography assay. ANIMALS: 6 healthy adult mixed-breed dogs. PROCEDURES: Dogs received each of 3 treatments (saline [0.9% NaCl] solution [1 to 2 mL, IV] and acepromazine maleate [0.05 and 0.1 mg/kg, IV]) in a randomized crossover study with a minimum 3-day washout period between treatments. From each dog, blood samples were collected via jugular venipuncture immediately before and 30 and 240 minutes after administration of each treatment. A modified thromboelastography assay, consisting of citrated kaolin-activated (baseline assessment), reptilase-ADP-activated (ADP-activated), and reptilase-arachidonic acid (AA)-activated (AA-activated) thromboelastography, was performed for each sample. Platelet inhibition was evaluated by assessing the percentage change in maximum amplitude for ADP-activated or AA-activated samples, compared with baseline values. Percentage change in maximum amplitude was analyzed by use of Skillings-Mack tests with significance accepted at a family-wise error rate of P < 0.05 by use of Bonferroni corrections for multiple comparisons. RESULTS: No significant differences were found in the percentage change of maximum amplitude from baseline for ADP-activated or AA-activated samples among treatments at any time. CONCLUSIONS AND CLINICAL RELEVANCE: Platelet function in dogs, as assessed by use of a modified thromboelastography assay, was not inhibited by acepromazine at doses of 0.05 or 0.1 mg/kg, IV. This was in contrast to previous reports in which it was suggested that acepromazine may alter platelet function via inhibition of ADP and AA.

Incidence of seizures associated with the use of acepromazine in dogs undergoing myelography.

OBJECTIVE: To investigate the frequency of seizures associated with acepromazine administration when used as a premedicant with methadone for dogs undergoing myelography. DESIGN: Retrospective clinical case study. SETTING: University veterinary teaching hospital. ANIMALS: Sixty-six dogs (mixed and pure breeds), aged between 4 months and 15 years, weighing between 3.5-61 kg. All animals were classified as ASA score I or II. INTERVENTIONS: Forty-three animals were premedicated with methadone (0.1-0.5 mg/kg) and acepromazine (0.01-0.05 mg/kg) intramuscularly. Twenty-three animals were premedicated with methadone alone (0.1-0.5 mg/kg) intramuscularly. Anesthesia was induced with propofol intravenously and maintained with isoflurane delivered in 100% oxygen. All animals received a balanced isotonic crystalloid solution intravenously at a rate of 10 mL/kg/h. Blood pressure, end-tidal CO(2) , oxygen saturation, respiratory rate, and heart rate were monitored throughout anesthesia. Animals requiring surgery immediately following myelography were excluded from the study. MEASUREMENTS AND MAIN RESULTS: The frequency of seizures was 14% (CI: 3.6-24.3%) and 13.0% (CI: 0.7-27%) in dogs that received methadone/acepromazine and methadone alone, respectively. There was no significant difference in the frequency of seizures between dogs receiving methadone/acepromazine or methadone alone (P = 1). Analysis of the association of site of injection of the contrast and the frequency of seizures in dogs receiving methadone/acepromazine showed no significant difference in the frequency of seizures following cervical injection (25%; CI: 0.5-24.5%) or lumbar injection (9.7%; CI: -0.7-20.1%). CONCLUSIONS: The administration of acepromazine combined with methadone as a premedicant used with propofol and isoflurane anesthesia did not significantly increase the frequency of seizures following myelography compared to dogs who received methadone alone.

[Effects of a neuroleptic analgesia with acepromazine on the blood perfusion of the canine kidney. Examination using the sonographic recordable blood circulation parameters of resistance index and pulsatility index]. / Auswirkung einer Neuroleptanalgesie mit Acepromazin auf die Durchblutung der Niere beim Hund. Überprüfung anhand der sonographisch erfassbaren Durchblutungsparameter Resistance-Index und Pulsatilitätsindex.

OBJECTIVE: Kidney failure after anaesthesia constitutes a serious clinical complication. A number of patients suffer from compensated kidney insufficiency, which may be transformed into an acute kidney insufficiency through additional stress, such as an operation and anaesthesia. The aim of the present study was to investigate the effects of a neurolept analgesia with acepromazine on sonographically accessible blood perfusion parameters. MATERIAL AND METHODS: Following anaesthesia with acepromazine/l-methadone (0.1 mg/kg BW acepromazine, 0.5 mg/kg BW l-methadone) a sonographic examination of the left kidney was performed in 19 clinically healthy foxhound and beagle dogs. Every 5 minutes resistance index and pulsatility index as well as invasive blood pressure were measured and digitally recorded. RESULTS: Within 5 minutes after induction of anaesthesia a transient increase of the mean arterial blood pressure occurred. After 10 minutes the blood pressure decreased to the initial value and remained essentially constant to the end of the investigation. Resistance index and pulsatility index showed a similar behaviour: After a small initial decrease during the first 5 minutes both parameters displayed a significant increase. This rise was very pronounced up to approximately 15 minutes and then flattened significantly until the end of the test period after 30 minutes. The values corresponded to those found in vessel stenosis. CONCLUSION AND CLINICAL RELEVANCE: Due to the described changes this type of anaesthesia should not be used in dogs with nephropathy, even though the results of this experimental study might not be necessarily transferable to the clinical patient.

Effects of acepromazine maleate or morphine on tear production before, during, and after sevoflurane anesthesia in dogs.

OBJECTIVE: To investigate the effects of acepromazine maleate and morphine on aqueous tear production before, during, and after sevoflurane anesthesia in dogs. ANIMALS: 6 mixed-breed dogs. PROCEDURES: In a Latin square study design, dogs underwent i.m. administration of morphine (1 mg/kg), acepromazine (0.05 mg/kg), or saline (0.9% NaCl) solution (0.05 mL/kg), followed by induction and maintenance of anesthesia with sevoflurane for 30 minutes. The protocol was repeated until all dogs had received all treatments, with a minimum of 7 days between anesthetic episodes. Aqueous tear production was measured via Schirmer tear test I before treatment (baseline); before anesthetic induction; 5, 10, 20, and 30 minutes after anesthetic induction; immediately once dogs recovered from anesthesia; and 2 and 10 hours after recovery. RESULTS: Aqueous tear production for all treatments was significantly lower 10, 20, and 30 minutes (but not 5 minutes) after anesthetic induction than at baseline, before anesthetic induction, at recovery, and 2 and 10 hours after recovery. Aqueous tear production was significantly higher after saline solution administration than after morphine administration at the preinduction measurement point and 2 hours after recovery. No other differences were detected among the 3 treatments. CONCLUSIONS AND CLINICAL RELEVANCE: Aqueous tear production after anesthesia did not differ significantly from baseline values after any treatment following 30 minutes of sevoflurane anesthesia, suggesting premedication with morphine or acepromazine does not contribute to a decrease in lacrimation in these circumstances.

Ambulatory esophageal pHmetry in healthy dogs with and without the influence of general anesthesia.

This research aimed to determine the value of esophageal pH in awake and anesthetized dogs, to evaluate the esophageal pH value in awake dogs, in different body positions, as well as to study the occurrence of gastroesophageal reflux episodes in these positions. Thus, 40 healthy male and female adult dogs with mean body weight of 15.5 ± 4.6 kg were used. Esophageal pHmetry was conducted by inserting a catheter through the oropharynx in 30 dogs (stage 1) anesthetized with acepromazine, propofol and isoflurane, submitted to elective ovariosalpingohysterectomy. In addition, 8-h esophageal pHmetry was carried out transnasally in 10 awake dogs (stage 2), allowed to move and change body positions (lateral and sternal decubitus, and standing position), which were recorded. The mean esophageal pH value was lower (p < 0.01) in the anesthetized dogs (7.3 ± 0.82) than in the awake dogs (8.2 ± 0.3). Only four anesthetized dogs (13.33%) suffered reflux episodes. Reflux was not observed in the awake dogs and no esophageal pH differences were found between the body positions studied. Compared to the alert state, general anesthesia in dogs submitted to the previously mentioned anesthesia protocol causes esophageal pH reduction and predisposes to the occurrence of gastroesophageal reflux episodes. Transnasal pHmetry of 8 h in healthy awake dogs reveals that the esophageal pH value is alkaline and does not vary according to body position. In these animals, decubitus position is not a determining factor for reflux episodes to occur.

Contemporary use of acepromazine in the anaesthetic management of male horses and ponies: a retrospective study and opinion poll.

REASON FOR PERFORMING STUDY: Current use of acepromazine in the anaesthetic management of male horses and ponies and associated risks are largely unknown. OBJECTIVES: To explore anaesthetic acepromazine use and related adverse effects in the male horse. METHODS: Of 8533 anaesthetised horses and ponies medical records of male animals treated perianaesthetically with acepromazine were reviewed. Demographic data, time and dose of acepromazine administration, co-administered drugs, quality of induction and recovery from anaesthesia, arterial blood pressures, and occurrence of penile dysfunction were recorded. Practising ACVA and ECVAA diplomates were polled on the use of acepromazine and its effects on blood pressure and penile dysfunction in the equine. RESULTS: Of all animals, 12% females and 11% males (n=575 including 42% stallions) received perianaesthetic acepromazine, predominantly for premedication. Anaesthetic induction was smooth in 566 animals. Lowest mean arterial pressures averaged 65±9 mmHg. Recovery was good or very good in 70% of all animals and 74% stood after 1-2 attempts. In 14 horses (2.4%; 7 stallions, 7 geldings), penile prolapse occurred for 0.5-4 h and in one stallion (0.2%) for >12 but <18 h post recovery. Most surveyed anaesthesiologists use acepromazine in stallions (occasionally 63%; frequently 17%) but more frequently in geldings (occasionally 34%; frequently 59%) and mares (occasionally 38%; frequently 59%), primarily for premedication with other sedatives and analgesics. Persistent intraoperative hypotension was not frequently reported. Only 5% of surveyed anaesthesiologists recall penile prolapse post acepromazine administration lasting for >12 h and only one recalls 3 cases of irreversible penile prolapse in 20 years of anaesthesia practice. CONCLUSIONS AND POTENTIAL RELEVANCE: The extremely low risk of permanent penile dysfunction (≤1 in 10,000 cases) does not justify more restricted use of acepromazine in the intact male vs. geldings and mares.

Effective and safe anesthesia for Yorkshire and Yucatan swine with and without cardiovascular injury and intervention.

The goal of this study was to identify an injectable anesthetic protocol that provides sedation sufficient for peripheral vascular catheterization, intubation, and transport while minimizing cardiovascular changes in Yorkshire and Yucatan pigs with and without cardiovascular injury and intervention (CI). Phase 1 examined the safety and efficacy of acepromazine-ketamine, diazepam-ketamine, midazolam-ketamine, and medetomidine-ketamine in 5 healthy Yorkshire pigs. For each drug combination, we obtained multiple measurements of heart rate, blood pressure, respiratory rate, temperature, sedation score, ability to catheterize and intubate, and recovery score. Phase 2 evaluated and refined the dose of the most effective Phase 1 anesthetic combination (midazolam-ketamine) in healthy and CI Yorkshire pigs (n = 53 trials). Phase 3 mirrored Phase 2 but tested midazolam-ketamine in healthy and CI Yucatan pigs (n = 34 trials). Midazolam (0.5 mg/kg)-ketamine (25 to 27 mg/kg) was the most effective anesthetic combination in healthy Yorkshire pigs, but this dose was less effective in healthy Yucatan pigs and CI Yorkshire and Yucatan pigs. Midazolam-ketamine resulted in tachycardia and apnea more frequently in CI pigs than healthy pigs. This combination also caused vomiting in one CI Yucatan pig. Overall, midazolam-ketamine provided safe and effective sedation for catheterization and intubation of both healthy and CI pigs. This study suggests Yucatan pigs may require a higher dose midazolam-ketamine to achieve the same level of sedation as that in Yorkshire pigs. Although anesthetic complication rates were higher in CI pigs, our results indicate that midazolam-ketamine can be safely used for sedation of both pig breeds with and without CI.