Intramuscular Dexmedetomidine Research Articles

A comparative analysis of opioid-free and opioid-sparing anaesthesia techniques for laparoscopic ovariectomy in healthy dogs

ObjectiveTo compare the perioperative analgesic effects of an opioid-free (OFA) and an opioid-sparing (OSA) anaesthetic protocol in dogs undergoing laparoscopic ovariectomy. Study designProspective, randomized, blinded, clinical trial. AnimalsA group of 28 client-owned dogs. MethodsDogs were allocated to one of two groups. The OFA group was administered intramuscular (IM) dexmedetomidine 5 μg kg–1 and ketamine 1 mg kg–1, followed by two intraoperative constant rate infusions (CRIs) of dexmedetomidine (3 μg kg–1 hour–1) and lidocaine (1 mg kg–1 loading dose, 2 mg kg–1 hour–1). The OSA group was administered IM dexmedetomidine 5 μg kg–1, ketamine 1 mg kg–1 and methadone 0.2 mg kg–1, followed by two intraoperative saline CRIs. In both groups, anaesthesia was induced with intravenous (IV) propofol 2 mg kg–1 and diazepam 0.2 mg kg–1 and maintained with isoflurane. Rescue dexmedetomidine (0.5 μg kg–1) was administered IV if there was a 20% increase in cardiovascular variables compared with pre-stimulation values. Ketorolac (0.5 mg kg–1) was administered IV when the surgery ended. Postoperative analgesia was evaluated using the Short Form-Glasgow Composite Measure Pain Scale and methadone (0.2 mg kg–1) was administered IM if the pain score was ≥ 6/24. Statistical analysis included mixed analysis of variance, Chi-square test and Mann–Whitney U test. ResultsThere were no significant differences in the intraoperative monitored variables between groups. The OFA group showed a significantly lower intraoperative rescue analgesia requirement (p = 0.016) and lower postoperative pain scores at 3 (p =0.001) and 6 (p < 0.001) hours. No dogs were administered rescue methadone postoperatively. Conclusions and clinical relevanceAlthough both groups achieved acceptable postoperative pain scores with no need for further intervention, the analgesic efficacy of the OFA protocol was significantly superior to that of the OSA protocol presented and was associated with a lower intraoperative rescue analgesia requirement and early postoperative pain scores.

Comparison of Subcutaneous versus Intramuscular Dexmedetomidine–Midazolam–Ketamine–Morphine (DMKM) Mixture as Chemical Restraint for Endoscopic Sex Determination in Aldabra Giant Tortoises (Aldabrachelys gigantea)

Comparison of Subcutaneous versus Intramuscular Dexmedetomidine–Midazolam–Ketamine–Morphine (DMKM) Mixture as Chemical Restraint for Endoscopic Sex Determination in Aldabra Giant Tortoises (Aldabrachelys gigantea)

A Comparative Study of Intramuscular Ketamine and a Combination of Intramuscular Dexmedetomidine and Ketamine as Premedication in Paediatric Anesthesia

Introduction: Preoperative anxiety is an issue of concern in paediatric anaesthesia practice. Forceful transfer of children into the operating room can cause long-term psychological trauma. This clinical study compares intramuscular ketamine and a combination of intramuscular dexmedetomidine and ketamine as anaesthetic premedicants in terms of +anxiolysis, sedation and ease of IV cannulation.&#x0D; Objectives: To compare the level of preoperative anxiety, sedation and ease of cannulation following premedication between intramuscular ketamine and a combination of intramuscular dexmedetomidine and ketamine.&#x0D; Methods: Total of 60 patients belonging to American Society of Anaesthesiologists physical status I-II, in the age group of two to ten years, scheduled for elective surgery under general anaesthesia were included in the study; Group A patients received ketamine 3mg/kg body weight while Group B patients received ketamine 2mg/kg body weight and dexmedetomidine 1mcg/kg body weight intramuscular. The outcome variables were sedation score (Richmond Agitation Sedation Scale), IV cannula acceptance (IV cannula Acceptance Score), and parental separation (Separation Score).&#x0D; Results: The groups were comparable in patient characteristics and hemodynamic parameters between the groups. Median (IQR) sedation score at 10 min were -1 (-2—0) and 0(-1—1) (p&lt; 0.001); mean parental separation scores were 3.76± 0.43 and 3.36±0.55 (p&lt; 0.001); IV cannula acceptance score were 3.73±0.44 and 4.53±7.27 (p= 0.001) in Group A and Group B respectively.&#x0D; Conclusion: Combination of dexmedetomidine and ketamine is superior to ketamine alone in terms of sedation at 15 min and ease of IV cannulation but comparable in terms of anxiolysis.

Pharmacokinetics and pharmacodynamics of intramuscular dexmedetomidine in dogs.

To determine the pharmacokinetics and pharmacodynamics of dexmedetomidine after IM administration in dogs. 6 healthy adult purpose-bred dogs (3 males, 3 females) with a mean ± SD body weight of 25.2 ± 1.8 kg. Each dog received 10 µg/kg dexmedetomidine, IM. Heart rate and respiratory rate were counted via cardiac auscultation and visual assessment of chest excursions. Sedation was assessed utilizing 2 sedation scoring systems. Plasma concentrations were determined using ultra performance liquid chromatography-mass spectrometry. Plasma concentrations versus time data after IM dexmedetomidine were analyzed using noncompartmental analysis for extravascular administration. Over the first 2 hours following IM injection of dexmedetomidine, plasma concentrations fluctuated in each dog. The geometric mean (range) maximum plasma concentration was 109.2 (22.4 to 211.5) ng/mL occurring at 20.5 (5 to 75) minutes, and the mean half-life was 25.5 (11.5 to 41.5) minutes. Heart rate was significantly lower than baseline from 30 minutes to 2 hours postdexmedetomidine administration, and respiratory rate was significantly lower than baseline from 45 minutes to 1.75 hours. Dogs were significantly more sedated from 30 minutes to 1.5 hours postdexmedetomidine administration. Median time to onset of sedation was 7.5 minutes (range, 2 to 10 minutes), and median time to peak sedation was 30 minutes (range, 15 to 60 minutes). Variations in plasma concentrations occurred in all dogs for the 2 hours postinjection of dexmedetomidine at 10 µg/kg, IM. This was likely due to alterations in absorption due to dexmedetomidine-induced local vasoconstriction. Despite variable plasma concentrations, all dogs were sedated following IM dexmedetomidine administration.

Efficacy of IM dexmedetomidine in alleviating catheter related bladder discomfort and postoperative inflammatory response following percutaneous nephrolithotomy. A prospective randomized controlled study.

Catheter-related bladder discomfort (CRBD) causes significant distress to the patient and requires great attention to analgesia and increases morbidity in the postoperative period. This study evaluated the efficacy of intramuscular dexmedetomidine in alleviating CRBD following percutaneous nephrolithotomy (PCNL) and postoperative inflammatory response. A prospective randomized double-blind study was conducted in a tertiary care hospital from December 2019- March 2020. Sixty seven of ASA I and II patients scheduled for elective PCNL were randomized and group I received 1 μg/kg dexmedetomidine intramuscularly and group II normal saline as control 30 minutes before induction of anesthesia. Standard anesthesia protocol was followed and patients were catheterized with 16 Fr Foleys after induction of anesthesia. Rescue analgesia was paracetamol if the score was moderate. Postoperatively CRBD score and inflammatory markers; total white cell count, erythrocyte sedimentation rate and temperature were noted for 3 days. There was a significant low CRBD score in group I. Ramsay sedation score was 2 in group I with p 0.00 and rescue analgesia required was very low with p 0.00. Statistical Package for social Sciences software version 20 was used for analysis. Student ttest, analysis of variance, and Chisquare test were applied for quantitative and qualitative analysis respectively. Single dose intramuscular dexmedetomidine is effective, simple and safe in preventing the CRBD and the inflammatory response remained uninfluenced except ESR, the reason remains largely unknown.

Efficacy of dexmedetomidine as adjuvant to bupivacaine in femoral-sciatic nerve blocks in dogs undergoing tibial plateau levelling osteotomy (TPLO)

The aim of this randomized, prospective clinical study was to evaluate the efficacy of dexmedetomidine combined with bupivacaine on sciatic and femoral nerve blocks in dogs. Thirty dogs were selected for elective unilateral tibial plateau levelling osteotomy, and each subject was assigned randomly to receive perineural bupivacaine 0.5% (0.1 mL/kg) and intramuscular dexmedetomidine (0.5 μg/kg) in the BDs group, perineural bupivacaine 0.5% (0.1 mL/kg) plus dexmedetomidine (0.5 μg/kg) in the BDloc group, and perineural bupivacaine 0.5% (0.1 mL/kg) plus intramuscular administration of saline solution the in Bupi group. Nerve blocks were guided by electrolocation. The main intraoperative parameters were registered 10 min before the start of surgery (BASE) and during the skin incision (SKIN), the osteotomy (BONE) and the suture (SUTURE). At 2, 4, 6, 8, 10, 15, 20 and 24 h after blocks, the Glasgow Composite Pain scale (GPCs) was used to identify the degree of pain during the postoperative period. Patients with scores ≥5/20 received rescue analgesia and were excluded. Furthermore, heart rate, mean arterial pressure, footstep capacity, reaction to wound touch and femoral and sciatic skin sensitivity were registered. Parametric data were compared at each time point of the study with the one-way ANOVA for repeated measures and Fisher's test for yes/no variables analysis (p < 0.05). No subject required intraoperative rescue analgesia. In BDloc group, the GCPs score was <5/20 for all dogs at all times of the study, and 70% of dogs did not need systemic analgesia. In the Bupi and BDs groups, 100% of subjects achieved a score ≥ 5/20 between 8 and 10 h after the blocks, and 100% of subjects showed femoral and sciatic skin sensitivity and required rescue analgesia within 10 h. Our results showed that the addition of dexmedetomidine as an adjuvant to bupivacaine in SF blocks may prolong the sensory block and ensure sufficient analgesia for up to 24 h in dogs undergoing TPLO surgery.

Comparison of two injectable anaesthetic protocols in Egyptian fruit bats (Rousettus aegyptiacus) undergoing gonadectomy

Egyptian fruit bats have gained increasing interest being a natural reservoir for emerging zoonotic viruses. Anaesthesia is often required to allow safe handling of bats. We aimed to compare the sedative and cardiopulmonary effects of two balanced anaesthetic protocols in bats undergoing gonadectomy. Group DK (n = 10) received intramuscular dexmedetomidine (40 µg/kg) and ketamine (7 mg/kg), whereas group DBM (n = 10) received intramuscular dexmedetomidine (40 µg/kg), butorphanol (0.3 mg/kg) and midazolam (0.3 mg/kg). Induction time and cardiopulmonary parameters were recorded. If anaesthetic plan was inadequate, isoflurane was titrated-to-effect. At the end of surgery venous blood gas analysis was performed and atipamezole or atipamezole-flumazenil was administered for timed and scored recovery. In DBM group heart rate and peripheral oxygen saturation were significantly higher (p = 0.001; p = 0.003 respectively), while respiratory rate was significantly lower (p = 0.001). All bats required isoflurane supplementation with no significant differences between groups. Induction and recovery times showed no significant differences. In group DK a better recovery was scored (p = 0.034). Sodium and chloride were significantly higher in DBM group (p = 0.001; p = 0.002 respectively). Both anaesthetic protocols were comparable and can be recommended for minor procedures in bats.

Comparison of the sedative effects of intranasal or intramuscular dexmedetomidine at low doses in healthy dogs: a randomized clinical trial

ObjectiveTo compare the sedative effects of dexmedetomidine administered either intranasally or intramuscularly to healthy dogs. Study designProspective, randomized, blinded, clinical trial. AnimalsA group of 16 client-owned healthy dogs. MethodsDogs were randomly allocated to one of two groups that were administered dexmedetomidine 5 μg kg–1 via either the intranasal route (INDex), through a mucosal atomization device in one nostril, or the intramuscular route (IMDex), into the epaxial muscles. Ease of intranasal administration, sedation score, onset of sedation, cardiopulmonary variables, mechanical nociceptive thresholds (MNTs) and response to venous catheterization were recorded at 0 (baseline), 5, 10, 15, 20, 25, 30, 35, 40 and 45 minutes, following drug administration. Data were compared with the one-way anova, Mann-Whitney U test, and chi-square test, where appropriate. ResultsGroups were not different for age, sex, weight, body condition score or temperament. Sedation scores, MNTs and response to intravenous catheter placement were not different when dexmedetomidine was administered by either route (p = 0.691; p = 0.630 and p = 0.435, respectively). Onset of sedation was not different between groups INDex and IMDex reaching a score of 4.2 ± 0.9 and 5.5 ± 1.2 at 9 ± 5 and 8 ± 4 minutes, respectively (p = 0.467). The highest sedation score was achieved at 30 and 35 minutes and sedation scores were 9.7 ± 2.0 and 9.5 ± 2.3 in groups INDex and IMDex, respectively (p = 0.799). Respiratory rate was higher in group INDex (p = 0.014), while there were no differences between routes in heart rate (p = 0.275), systolic (p = 0.957), diastolic (p = 0.837) or mean arterial pressure (p = 0.921). Conclusions and clinical relevanceIntranasal administration of dexmedetomidine at 5 μg kg–1 provides effective sedation in healthy dogs.

Effects of intranasal and intramuscular dexmedetomidine in cats receiving total intravenous propofol anesthesia.

Background and Aim:The efficacy of intranasal (IN) dexmedetomidine in cats as a premedication remains elusive. Thus, this study aimed to compare the perioperative and sparing effects of IN and intramuscular (IM) dexmedetomidine administration on propofol requirements for anesthetic induction in cats.Materials and Methods:This study randomly assigned 16 cats into two groups of IN or IM dexmedetomidine at 20 μg/kg. Sedation scores and side effects were recorded at time points of 0, 5, 10, 15, and 20 min after the dexmedetomidine administration. Anesthesia was induced with intravenous (IV) 1% propofol by titrating a bolus of 2 mg every 45 s and the total dose of the administered IV propofol to achieve endotracheal intubation was recorded.Results:Cats receiving IM dexmedetomidine were significantly associated with higher sedation scores. All cats were sedated at 20 min after premedication; however, the average composite sedation scores in the IN group were significantly lower than those in the IM group during premedication. Pre-operative side effects, including vomiting, were more frequently observed in the IN group (5 cats, 62.5%) than in the IM group (3 cats, 37.5%; p < 0.05). Higher body temperature (>1°F compared to baseline) was more frequently observed in the IN group (6 cats, 75.0%) than in the IM group (1 cat, 12.5%; p < 0.05). The dosage of required propofol in the IN group was significantly higher (1.1 ± 0.3 mg/kg) than that in the IM group (0.7 ± 0.2 mg/kg; p < 0.05). The duration of general anesthesia was comparable between the groups.Conclusion:IN dexmedetomidine produces moderate sedation and cats may have side effects, including vomiting and higher body temperature. Higher sparing effects of propofol were identified in the IM group compared with the IN group. Nonetheless, IN administration of dexmedetomidine provides a noninvasive alternative to the IM route.

Comparison of blind and endoscopic-guided orotracheal intubation on laryngeal and tracheal damage in domestic rabbits (Oryctolagus cuniculus)

ObjectiveTo compare blind and endoscopic-guided techniques for orotracheal intubation in rabbits and the number of intubation attempts with laryngeal/tracheal damage. Study designProspective, randomized experimental study. AnimalsA total of 24 healthy, intact female New Zealand White rabbits, weighing 2.2 ± 0.2 kg (mean ± standard deviation). MethodsRabbits were randomly assigned to blind (group B) or endoscopic-guided (group E) orotracheal intubation with a 2.0 mm internal diameter uncuffed tube. Intramuscular (IM) alfaxalone (7 mg kg–1), hydromorphone (0.1 mg kg–1) and dexmedetomidine (0.005 mg kg–1) were administered, and additional IM alfaxalone (3–5 mg kg–1) and dexmedetomidine (0.025 mg kg–1) were administered to rabbits with strong jaw tone. An intubation attempt was defined as the advancement of the endotracheal tube from the incisors to the laryngeal entrance. Tracheal intubation was confirmed via capnography and anesthesia was maintained with isoflurane for 2 hours. Following euthanasia, laryngeal and tracheal tissues were submitted for histopathology. Quality of anesthesia for orotracheal intubation, intubation procedure and tissue damage were numerically scored. Data were analyzed using Poisson regression, Spearman’s correlation, t test, mixed anova, Mann–Whitney U test, Friedman and Chi square tests as appropriate. ResultsMedian (range) intubation attempts were 2 (1–8) and 1 (1–3) for groups B and E, respectively. More rabbits in group E (91.6%) required additional alfaxalone and dexmedetomidine than in group B (16.7%). Median (range) cumulative histopathology scores were 6 (3–10) and 6 (2–9) for groups B and E, respectively. Scores were highest in the cranial trachea, but there was no difference between groups and no correlation between laryngeal/tracheal damage and the number of intubation attempts. Conclusions and clinical relevanceBoth orotracheal intubation techniques were associated with laryngeal/tracheal damage. Although blind orotracheal intubation was associated with a higher number of attempts, the tissue damage was similar between groups.

Feasibility of non-invasive recording of somatosensory evoked potential in pigs

BackgroundNon-invasive measurement of somatosensory-evoked potentials (SEP) in a large animal model is important to translational cognitive research. We sought to develop a methodology for neurophysiological recording via a transcranial electroencephalography (EEG) cap under an effective sedative regimen with dexmedetomidine, midazolam, and butorphanol that will produce sedation instead of anesthesia while not compromising data quality.ResultsPigs received intramuscular dexmedetomidine, midazolam, and butorphanol for SEP assessment with peroneal nerve stimulation. Semi-quantitative sedation assessment was performed after the animal was sufficiently sedated and 30 min later, during the transcranial SEP recording. SEP data were analyzed with commercial software. Binary qualitative analysis of the recording was categorized by an experienced neurophysiologist. All four animals had adequate surface SEP recordings. Animals received 43 [21–47] mcg/kg of dexmedetomidine, 0.3 [0.2–0.3] mg/kg of midazolam, and 0.3 [0.3–0.3] mg/kg of butorphanol IM. All treatments resulted in moderate to deep sedation (Baseline median sedation score 11.5 [11–12]; median score at 30 min: 11.5 [10.5–12]). Heart rate (median [range]) (55 [49–71] beats per minute), respiratory rate (24 [21–30] breaths per minute), and hemoglobin oxygen saturation (99 [98–100]%) and body temperature (37.7 [37.4–37.9] °C) remained within clinically acceptable ranges. There were no undesirable recovery incidents.ConclusionsIn this pilot study, we demonstrate the feasibility of SEP recording via a transcranial EEG cap under an effective sedative regimen in pigs. Our approach will expand the use of a large animal model in neurotranslational research.

Effect of Intramuscular Dexmedetomidine Administration Before Extubation on Post-Extubation Haemodynamics, Postoperative Sedation, and Analgesic Requirements: A Double Blind Placebo Controlled Study.

Dexmedetomidine, an α2-adrenoreceptor agonist has been successfully used for attenuating stress response to laryngoscopy. The present study was designed to evaluate the effects of intramuscular dexmedetomidine 30 minutes before extubation on hemodynamic response in patients undergoing laminectomy for prolapsed intervertebral disc (PIVD) under endotracheal intubation and general anesthesia. Present double-blinded randomized placebo-controlled study, included 100 patients from either sex with American Society of Anesthesiologists grades I and II and age from 18 to 60 years undergoing laminectomy for PIVD under general anesthesia. Patients were randomly divided into two groups of 50 each based on computer generated random numbers. The study group received dexmedetomidine (2.0 μg/ kg, i.m.) in 2.5 mL saline, and the control group received normal saline (placebo, i.m.) 2.5 mL. Drugs had been administered 30 minutes before anticipated time of extubation intramuscularly at the deltoid region. Comparison of continuous variables between two groups was done by using student's unpaired t-test. Categorical data were analyzed by using chi-square test and Fischer Exact test as applicable. Heart rate was found to be significantly lower in the study group, 15 minutes before extubation (P = 0.003), during and after extubation (P ＜ 0.0001). The systolic and diastolic blood pressure was significantly lower in the study group during and after extubation (P ＜ 0.05). Cough was significantly lower in the study group during extubation. No significant difference was observed in other complications (respiratory stridor, incidence of laryngospasm or bronchospasm and reintubation) between the two groups. Pain score at 5 minutes, 2 hours, and 4 hours post-extubation was significantly lower in the study group (P ＜ 0.01). P-value ＜ 0.05 was considered statistically significant. Dexmedetomidine provides haemodynamic stability during extubation and post-extubation. It also provides post-operative calmness and reduces analgesic requirement and post-extubation complications.

Sedative Effects of Intramuscular Dexmedetomidine and Ketamine at Sub-Anesthetic Dose Alone or in Combination with Methadone in Healthy Dogs

The aim of the present study was to compare sedation quality and cardiorespiratory parameters in healthy dogs after intramuscular injection of dexmedetomidine and ketamine with or without methadone. Forty client-owned dogs were randomly divided into two groups and received IM dexmedetomidine (5 µg kg−1) and ketamine (1 mg kg−1), associated (DKM group) or not (DK group) with methadone (0.2 mg kg−1). Sedation, heart rate (HR), respiratory rate (ƒR), mucous membrane and rectal temperature were recorded at baseline (T0) and after 5 (T5), 10 (T10) and 20 (T20) minutes. From T10, cardiac rhythm was monitored with a continuous lead II electrocardiogram. Ease of venous catheter placement, total propofol dose and any apnea episodes were recorded. Sedation was significantly greater in the DKM group, and a significant increase from T5 to T20 within DKM (P = .0002) and DK (P = .008) was also observed. Within each group, HR was significantly lower at all time points compared to baseline. No significant differences between groups were found in the number of arrhythmogenic events (atrioventricular blocks). In both group ƒR decreased over time. The propofol dose required for anesthesia induction was significantly lower (P = .027) in the DKM group. In conclusion, a good level of sedation was achieved in both groups, although this was greater in DKM. Smooth animal-operator interaction and ease of venous catheter placement showed that DK was a useful sedative protocol in healthy patients.

English

BACKGROUND The major concern of laparoscopic surgery is intra-operative hypercapnia induced stress response such as increase in heart rate (HR), increase in blood pressure (BP), increased stress hormones. The major concern of anaesthetist is to reduce stress response perioperatively. Drugs like clonidine, dexmedetomidine, nitroglycerine and esmolol are used to control the hemodynamic response associated with pneumoperitoneum in laparoscopic surgeries. Dexmedetomidine has been found to have hemodynamic stability with good analgesic effect. Dexmedetomidine is a highly selective α2 agonist with sedative, analgesic and sympatholytic properties. Here in this prospective randomized controlled study, we evaluate the effects of intramuscular dexmedetomidine as a premedication in laparoscopic cholecystectomy METHODS This is a randomized controlled study. Forty patients aged 20 to 50 years, both sexes, with American society of anaesthesiology (ASA) grade I &amp; II planned for elective laparoscopic cholecystectomy were randomly assigned into two groups, Group DS : (N - 20) Received 2 mcg/kg of dexmedetomidine with normal saline (total 2 ml) Group CS : (N - 20) Received 2 ml of normal saline as intramuscular injection in the deltoid region 60 minutes before induction. We compared the hemodynamic parameters like pulse rate, mean arterial pressure (MAP) in baseline, preinduction, during intubation, before and after carbon dioxide insufflation, post extubation, visual analog score (VAS) and the analgesic requirements in both groups RESULTS Compared to control group, intramuscular dexmedetomidine group had statistically significant reduction in pulse rate, mean arterial pressure perioperatively during intubation, before and after carbon dioxide insufflation, during surgery and post extubation (P &lt; 0.001) and also found to decrease the analgesic requirement post operatively CONCLUSIONS 2 mcg/kg intramuscular dexmedetomidine premedication produces better hemodynamic stability, reduced perioperative analgesic requirement and hence could be a better alternative to other premedicant agents. KEYWORDS Dexmedetomidine, IM Premedication, Laparoscopy, Stress Response

A comparison of administration of oral chloral hydrate with intranasal dexmedetomidine in sedation of children to perform electroencephalography

Background: Electroencephalography is a record of the electrical activity of the brain that is used to diagnose brain dysfunction and to determine the location of brain injury and to determine seizure activity. There is. The sedative medication used should not only have an effect on the brain’s electrical activity, but it also calms the baby. Since there have been no studies to compare the effects of intranasal oral hydrate and dexmedetomidine on sedation in children for electroencephalography, this study aimed to compare the effects of intranasal intravenous dexmedetomidine with intramuscular dexmedetomidine on electroencephalography in children. Methods: This clinical trial study was performed on 62 children candidates for electroencephalography in Imam Hossein Pediatric Hospital in Isfahan. Age, weight, and clinical data including sedation score, mean arterial pressure, respiratory rate, arterial oxygen saturation, and heart rate at pre-medication times, 15, 30, 45, and 60 minutes after drug administration. And analyzed. Results: The mean age of the children candidates for electroencephalography was 16.90 ± 1.32, out of which 35 (56.5%) were male. The results showed no significant difference between the two groups in terms of sedation, mean arterial pressure, respiratory rate, and percentage of arterial oxygen saturation (p&gt; 0.05). But the difference between the two groups was statistically significant for the variable heart rate. Heart rate was significantly lower in group B (dexmedetomidine group) than in group A (oral chlorate hydrate group) (p-value = 0.032), and time as an influencing factor in changing mean sedimentation, mean arterial pressure, respiratory rate, and heart rate (p-value &lt;0.05). But there was no significant effect on the change in arterial oxygen saturation percentage (p = 0.478). Conclusion: Chloral hydrate administration was more effective than intranasal dexmedetomidine treatment in maintaining heart rate but overall the results showed no significant difference between the two groups in terms of clinical data and child sedation score in the two groups. Was.

Retrospective Comparison of Intramuscular Admixtures of Ketamine and Dexmedetomidine Versus Ketamine and Midazolam for Preoperative Sedation.

Precooperative children and patients with intellectual disabilities often require intramuscular (IM) sedation prior to the induction of general anesthesia (GA). Ketamine is an effective preinduction sedative but can produce significant adverse side effects. Dexmedetomidine, a sedative with sympatholytic and analgesic properties, may provide advantages when used in combination with ketamine. This retrospective study evaluated the efficacy and safety of IM ketamine with dexmedetomidine for preoperative sedation. We conducted a chart review of all patients (n = 105) treated for dental rehabilitation who received either IM ketamine and dexmedetomidine (study group, n = 74) or IM ketamine and midazolam (control group, n = 31) prior to induction of GA. No significant difference (p = .14) was observed in the time interval from IM administration to operating room entry (median [interquartile range]) between the study and control groups (5 [4-8] vs 5 [2-7] minutes). Patients who received IM dexmedetomidine exhibited significantly lower mean arterial pressures throughout the induction (p = .004) and had lower heart rates (p = .01) throughout the intraoperative period compared with patients who did not receive dexmedetomidine. The combination of dexmedetomidine and ketamine may provide effective and safe IM sedation prior to the induction of GA.

Dexmedetomidine and Tear Production: Evaluation in Dogs as Spontaneous Model for Ocular Surface Disorders.

Simple SummaryThe general anesthesia or sedation reduces both the tear production and the stability of tear film that protect corneal surface, predisposing itself to the exposure keratopathy. The aim of the present study was to evaluate the effects of intramuscular dexmedetomidine (DEX) on canine tear production, measured by standardized Schirmer Tear Test 1 (STT-1) strips, for the 8 h following sedation, in dogs. A significant effect of time on canine tear production was found, highlighting that dexmedetomidine sedative protocol significantly affects tear production in dogs. It is recommended to treat the canine eyes with tear substitutes to protect ocular surface health and the welfare of the dogs. The ocular lubrication should be performed during and up to 12 h after sedation. The present report could provide preliminary information to better understand the effect of DEX on the tear film dynamics. Tear film provides lubrication and protection to the ocular surface. The sedation reduces tear production, often leading to perioperative exposure keratopathy. The aim of the present study was to report the effects of intramuscular dexmedetomidine on canine tear production, measured by STT-1, for an experimental period of 8 h after sedation. Ten dogs who underwent sedation for routine radiologic assessment were recruited for the study. In all animals, tear production in right and left eyes was measured 15 min before sedation (T0: basal values) and 20 min (T20), 1 h (T1), 2 h (T2), 4 h (T4) and 8 h (T8) after drug administration. Analysis of variance and post hoc Bonferroni test (p < 0.05) were performed. A significant effect of time on canine tear production was found. The tear production returned to basal values at T8. So, it is recommended to treat the canine eyes with tear substitutes during and up to 12 h after sedation.

Efficacy of dexmedetomidine as an adjuvant in femoral nerve block for post-op pain relief in hip surgery: A prospective randomized double-blind controlled study.

Background and Aims:To determine whether the addition of dexmedetomidine either in peripheral block or via systemic route leads to prolongation of the duration of analgesia is inconclusive. The present study aimed to assess the duration of postoperative analgesia with dexmedetomidine used as an additive with bupivacaine for ultrasound-guided femoral nerve block (FNB) and to compare it with intramuscular dexmedetomidine along with FNB.Material and Methods:A prospective, double-blind randomized clinical trial involving adult patients undergoing elective hip surgery, performed under subarachnoid block. When sensory block receded to T12 after the surgery, FNB was given for postoperative analgesia. Patients were randomized into three groups; Group A received FNB with 40 mL 0.25% bupivacaine and 0.5 mL saline as IM injection, Group B received FNB with 39.5 mL of 0.25% bupivacaine + 0.5 mL (50 mcg) of dexmedetomidine in the affected limb and 0.5 mL saline IM injection, and Group C received FNB with 40 mL of 0.25% bupivacaine and 0.5 mL (50 mcg) of dexmedetomidine as IM injection. Postoperative pain was assessed and for pain with VAS score >3, intravenous tramadol was given as rescue analgesia. Chi-square test for categorical variables and one-way ANOVA for continuous variables.Results:The mean duration of analgesia in groups A, B, and C was 671, 676, and 490 min, respectively which was not significant. A 24 h analgesic requirement was also not different between the groups.Conclusion:The use of dexmedetomidine perineurally or systemically did not prolong the duration of analgesia as compared to bupivacaine alone for femoral nerve block.

Anesthetic Management of a Brown Bear (Ursus arctos) Captive Undergoing Incisional Biopsy of a Skin Nodule

Background: The brown bear (Ursus arctos) is considered one of the largest terrestrial carnivores, native from temperate forest regions of North America, Europe and Asia. In Brazil, they are founded in captivity and their safe capture and immobilization are obtained with one effective anesthesia for management and surgical and diagnostic procedures. Some anesthetic protocols are described for these purposes, however, there is a lack for data on the anesthetic and adverse effects they have on bears when used. The aim of this case is to report the use and effects of the association of dexmedetomidine with tiletamine and zolazepam in the chemical containment of a captive adult brown bear.Case: A 33-year-old female brown bear, weighing 100 kg, belonging to the Zoobotanic Park of Teresina, Piauí, Brazil, was chemically immobilized for an incisional biopsy of a cutaneous nodule with 1.0 cm diameter in the right face region. The anesthetic protocol included 6 μg/kg of dexmedetomidine associated with 3 mg/kg of tiletamine and zolazepam, administered intramuscularly by dart into the gluteal region of the right pelvic limb. The animal showed moderate ataxia at 5 min and assumed sternal decubitus 7 min after anesthetic administration. The bear's degree of sedation was considered adequate and safe to perform the biopsy at 10 min after administration. Heart rate (47 ± 3 bpm), respiratory rate (17 ± 2 mpm) and rectal temperature (38.7 ± 0.1ºC) were monitored. The bear remained immobile and unconscious throughout the procedure, with intense muscle relaxation, bilateral eyeball rotation, absent lateral palpebral reflex and mild medial reflex and without nystagmus. Complementary sedative doses were not necessary. At the beginning of anesthetic recovery, the bear received 6 µg/kg of atipamezole, intramuscularly. After 25 min of administration of atipamezole, the animal showed signs of recovery in the level of consciousness and reactivity to external stimuli, and assumed the quadrupedal position at 60 min after reverser application.Discussion: Even in captivity, the bears behavior is unpredictable and attack can occur, causing trauma or death to people. For this, the chemical immobilization is important to keep safety of everyone. This procedure was performed using blowgun-assisted darts thrown by a staff member who had experience in using this method, who darted accurately and effectively. The latency time observed after administration of the anesthetic protocol used is similar to reported in other studies with bears that also received intramuscular dexmedetomidine and tiletamine and zolazepam and showed intense muscle relaxation and immobility. The doses used contributed to the absence of bradycardia and hypoventilation and, performing the procedure in the morning, when the temperature is milder in the city, minimized the chance of hyperthermia and thermal stress in the animal, not requiring body cooling. The use of dexmedetomidine in chemical containment protocols for short and minimally invasive procedures allows the subsequent use of its antagonist, atipamezole, contributing to a shorter recovery time, return of the animal’s degree of consciousness and lower incidence of ataxia after assuming a quadrupedal position. The anesthetic protocol used was considered efficient, providing a quick and gentle chemical containment, adequate anesthetic plan and good anesthetic recovery in an adult brown bear from captivity.Keywords:atipamezole, dexmedetomidine, wildlife.Título: Manejo anestésico de um urso pardo (Ursus arctos) cativo submetido a biópsia incisional de nódulo cutâneoDescritores: atipamezole, dexmedetomidine, animais selvagens.

Oral Transmucosal or Intramuscular Administration of Dexmedetomidine-Methadone Combination in Dogs: Sedative and Physiological Effects.

Simple SummaryDuring the last decade, new alternative non-invasive administration routes for drug delivery have gained interest in veterinary medicine. The administration of drugs via the oral transmucosal route is non-invasive, painless, easy to perform, and generally well tolerated. Furthermore, it avoids gastric acid degradation typical of oral administration. All these characteristics contribute to make this administration route very attractive, especially for veterinary patients who are difficult to inject, fearful, or anxious. In contrast, intramuscular injection is associated with pain and requires more invasive restraint, potentially incrementing patients’ discomfort. The aim of this study was to assess and compare the sedative and clinical effects of a dexmedetomidine–methadone combination following either oral transmucosal and intramuscular administration in healthy dogs and to record any possible adverse effects following each administration route. The present study suggests that oral transmucosal administration of dexmedetomidine and methadone combination provided a satisfactory level of sedation, allowing safe handling of the patients with less pronounced cardiorespiratory effects. Indeed, thanks to the lesser impact on the cardiac function, it could be considered as a useful option for those patients difficult to restrain in which cardiovascular stability should be preserved.The aim of this study was to compare the sedative and physiological effects following either oral transmucosal (OTM) or intramuscular administration of dexmedetomidine–methadone combination in healthy dogs. Thirty dogs were randomly assigned to receive a dexmedetomidine–methadone combination either by the OTM (n = 15) or intramuscular (n = 15) route. Sedation was scored 10, 20, and 30 min after drugs administration. Heart rate (HR), non-invasive blood pressure (NIBP), respiratory rate (fR), and body rectal temperature were recorded before drugs administration and then every 10 min for 30 min. Propofol dose required for orotracheal intubation was recorded. Sedation scores increased over time within both groups with higher values in intramuscular group (p < 0.05). Within each group, HR decreased significantly compared with baseline (p < 0.001) and was significantly lower in intramuscular group compared with the OTM group (p < 0.001). In both groups, NIBP increased significantly compared with baseline (p < 0.05). In the intramuscular group, fR was lower compared with the OTM group at all the observational time points (p < 0.001). Propofol dose was lower in the intramuscular group (p < 0.05). Compared to intramuscular dexmedetomidine–methadone, OTM combination produced lower but effective sedation in healthy dogs.