Comparison of sedation with dexmedetomidine/atipamezole administered subcutaneously at GV20 acupuncture point with usual routes of administration in dogs presented for orthopaedic radiographs.

OBJECTIVES: To evaluate the efficacy of subcutaneous administration of dexmedetomidine/atipamezole at the Governing Vessel 20 (GV20) acupuncture point compared with other administration routes (intramuscular and intravenous) in dogs presented for orthopaedic radiographs. MATERIALS AND METHODS: Prospective, randomised, blinded, controlled clinical study. Sixty-four client-owned dogs were randomly injected with 200 µg/m2 of dexmedetomidine intramuscular (lumbar muscles) (n=20), intravenous (n=23) or subcutaneous at the GV20 point (n=21). Following radiographs, dogs received 2000 µg/m2 of atipamezole intramuscular (n=31), or subcutaneous at the GV20 point (n=27). Degree and time to sedation and recovery were assessed using a sedation scale and a Dynamic and Interactive Visual Analog Scale (DIVAS). Clinical physiological variables and adverse events were used. Statistical linear mixed-effect models (analysis of variance) and Cox models were performed. Significance was set at P-value <0.05. RESULTS: Sedation was insufficient to perform orthopaedic radiographs in six dogs in the intramuscular group. The time to sedation was significantly longer, and sedation scale and DIVAS scores were significantly lower in the intramuscular group. The intravenous group had significantly higher sedation scale and DIVAS scores than the GV20 group. No significant differences were observed between the intramuscular and GV20 recovery groups, although the time effect was significantly more pronounced in the GV20 recovery group. CLINICAL SIGNIFICANCE: Subcutaneous administration of dexmedetomidine and atipamezole at GV20 provided effective sedation and recovery in dogs undergoing orthopaedic radiographic studies. GV20 administration provided a clinically similar level of sedation to the intravenous route, and greater and faster sedation and similar recovery to intramuscular.

More than Drug Fever: Dexmedetomidine-Induced Hyperthermia in a Critically Ill Patient.

Dexmedetomidine is a selective alpha-2 adrenergic agonist utilized for sedation in critically ill patients.1 We present the case of a morbidly obese critically ill patient who experienced profound hyperthermia, with a maximum temperature of 41.4°C, hours after starting a dexmedetomidine infusion that was otherwise not explained by her clinical diagnoses. The hyperthermia resolved hours following cessation of the infusion. Dexmedetomidine was assessed as probable in terms of causing this adverse effect. Dexmedetomidine may be associated not only with low-grade fever, but as demonstrated in our case, it may be associated with significant temperature elevations requiring cessation of therapy to restore normothermia.

Effects of dexmedetomidine on cardiac electrophysiology in patients undergoing general anesthesia during perioperative period: a randomized controlled trial.

BACKGROUND: Dexmedetomidine has controversial influence on cardiac electrophysiology. The aim of this study was to explore the effects of dexmedetomidine on perioperative cardiac electrophysiology in patients undergoing general anesthesia. METHODS: Eighty-one patients were randomly divided into four groups: groups D1, D2, D3 receiving dexmedetomidine 1, 1, 0.5 µg/kg over 10 min and 1, 0.5, 0.5 µg/kg/h continuous infusion respectively, and control group (group C) receiving normal saline. Twelve-lead electrocardiograms were recorded at the time before dexmedetomidine/normal saline infusion (T1), loading dose finish (T2), surgery ending (T6), 1 h (T7) after entering PACU, 24 h (T8), 48 h (T9), 72 h (T10) and 1 month (T11) postoperatively. Cardiac circulation efficiency (CCE) were also recorded. RESULTS: Compared with group C, QTc were significantly increased at T2 in groups D1 and D2 while decreased at T7 and T8 in group D3 (P < 0.05), iCEB were decreased at T8 (P < 0.05). Compared with group D1, QTc at T2, T6, T7, T9 and T10 and iCEB at T8 were decreased, and CCE at T2-T4 were increased in group D3 significantly (P < 0.05). Compared with group D2, QTc at T2 and iCEB at T8 were decreased and CCE at T2 and T3 were increased in group D3 significantly (P < 0.05). CONCLUSIONS: Dexmedetomidine at a loading dose of 0.5 µg/kg and a maintenance dose of 0.5 µg/kg/h can maintain stability of cardiac electrophysiology during perioperative period and has no significant adverse effects on CCE. TRIAL REGISTRATION: ClinicalTrials.gov NCT04577430 (Date of registration: 06/10/2020).

Safety of Dexmedetomidine as an Alternative Pediatric Magnetic Resonance Imaging (MRI) Sedative: A Retrospective Single-Center Study.

BACKGROUND Dexmedetomidine provides anxiolysis, sedation, dose-dependent hypnosis, and mild analgesia with minimal respiratory function effects. The aim of this study was to assess the efficacy and safety of dexmedetomidine for pediatric patients during MRI. MATERIAL AND METHODS We retrospectively analyzed 87 cases of pediatric sedations for MRI. Dexmedetomidine and a single dose of midazolam were used in all the cases, according to the in-house pediatric sedation protocol for MRI. The patients were divided in to 2 groups: group 1, who reached adequate sedation up to 10 min of induction and group 2, who achieved proper sedation after 10 min. RESULTS The median age was 3 years (0-17). The median duration of procedure was 75 min (40-150). The induction of standardized sedation was performed without additional sedatives and proper depth of sedation was reached in the majority of cases (94.3%). Five patients (5.7%) received additional sedative after 10 min of induction. The median time of adequate sedation was 8 min (3-13) after induction, and 51% of patients achieved RASS-4 in 8 min. There was no significant difference between groups 1 and 2. Ten patients (11.5%) experienced bradycardia, regardless of the usage of additional drugs, dexmedetomidine boluses, duration of the procedure, or induction time. CONCLUSIONS High-dose dexmedetomidine with a single dose of midazolam might be an effective combination at the induction stage for pediatric sedation for MRI, with very few adverse events. Over 50% of enrolled patients achieved an adequate level of sedation before 10 min. We conclude that induction of dexmedetomidine infusion can be shortened up to 8 min.

Comparison of adjuvant pharmaceuticals for caudal block in pediatric lower abdominal and urological surgeries: A network meta-analysis.

STUDY OBJECTIVE: Caudal block helps relieve pain after sub-umbilical surgery in pediatric patients; however, the duration for which it exerts its analgesic effect is limited. The addition of certain adjuvant agents to local anesthetics (LAs) that are used to administer caudal block can prolong postoperative analgesia. Therefore, we aimed to compare the efficiencies and side effects of caudal adjuvants in the settings of pediatric lower abdominal and urological surgeries. DESIGN: A network meta-analysis (NMA). PATIENTS: One hundred and twelve randomized controlled trials (RCTs) involving 6800 pediatric patients were included in the final analysis. INTERVENTIONS: Different adjuvant agents, namely clonidine, dexamethasone, dexmedetomidine, fentanyl, ketamine, magnesium, midazolam, morphine, neostigmine, and tramadol. MEASUREMENTS: The primary outcome was the duration of analgesia. The secondary outcomes included the requirement for additional analgesia, analgesic consumption, and postoperative complications. The effects and rankings were evaluated using NMA and the surface under the cumulative ranking curve scores, respectively. RESULTS: Neostigmine, dexmedetomidine, and dexamethasone were found to be the three most effective adjuvants that prolong the duration of analgesia for caudal block, and these adjuvants extended this duration by 8.9 h (95% confidence interval [CI], 7.1-10.7), 7.3 h (95% CI, 6.0-8.6), and 5.9 h (95% CI, 4.0-7.7), respectively. Caudal neostigmine was associated with an increase in the incidence of postoperative nausea and vomiting, whereas dexmedetomidine and dexamethasone showed no postoperative complications. CONCLUSIONS: This NMA provided evidence and suggested that dexmedetomidine and dexamethasone may be the most beneficial adjuvant pharmaceutics adding to LAs for caudal block in children. However, given the off-label status of caudal dexmedetomidine and dexamethasone, further high-quality RCTs are still warranted, especially to determine whether delayed neurological complications will occur.

Safety of peritoneal dialysis catheter surgery under dexmedetomidine and local anesthesia for elderly patients in Japan: a single-center prospective cohort study.

BACKGROUND: The number of patients aged ≥ 75 years and who need renal replacement therapy is steadily increasing. The study aimed to determine the safety of open surgery for peritoneal dialysis (PD) catheter placement in such patients. METHODS: This prospective cohort study included patients who underwent PD catheter placement by open surgery under dexmedetomidine (DEX) and local anesthesia at our institution from January 2015 to February 2021. Patients were divided into the following two groups according to age at the time of surgery: ≥ 75 years (group A) and < 75 years (group B). We compared the perioperative and postoperative complications (i.e., time to the first PD-related peritonitis and catheter obstruction requiring surgical intervention within 1 year) between the groups. RESULTS: A total of 118 patients were categorized into groups A (n = 65) and B (n = 53). No significant intergroup differences were observed in the postoperative fever, total duration of surgery, perioperative hemoglobin decrease, changes in the white blood cell count and C-reactive protein, postoperative catheter leakage, postoperative hospital stay, time to the first PD-related peritonitis, and catheter obstruction requiring surgical intervention within 1 year. CONCLUSIONS: The surgery for PD catheter placement by open surgery under DEX and local anesthesia in elderly patients is safe and effective.

Dexmedetomidine Sedation for Paroxysmal Supraventricular Tachycardia Ablation Is Not Associated With Alteration of Arrhythmia Inducibility.

BACKGROUND: Dexmedetomidine (Dex) is an attractive agent for procedural sedation due to its unique pharmacodynamic profile, specifically affording predictable sedation without concurrent respiratory depression. However, Dex has previously been reported to prevent or terminate arrhythmias. The purpose of this study was to investigate paroxysmal supraventricular tachycardia (PSVT) inducibility and homeostatic stability during electrophysiology studies (EPSs) and ablation when a standardized Dex protocol was used as the primary sedation agent. METHODS: We performed a retrospective review of 163 consecutive procedures for PSVT ablation that received Dex as the primary sedative with adjunct fentanyl and midazolam boluses (DEX-FENT-MIDAZ). This cohort was compared to 163 consecutive control procedures wherein strictly fentanyl and midazolam were used for sedation. The primary outcome reviewed was PSVT inducibility assessed before ablation. Reviewed secondary outcomes included level of sedation and intraprocedure hemodynamics and oxygenation. RESULTS: The arrhythmia profiles of the DEX-FENT-MIDAZ and control cohorts were very similar. The overall incidence of a "negative" EPSs in which arrhythmia was not induced was 24% in the DEX-FENT-MIDAZ group and 26% in the control group (P = .7). Unintended deep sedation was significantly less with DEX-FENT-MIDAZ (4.3% vs 27%; P ≤ .0001). However, DEX-FENT-MIDAZ use was associated with a higher incidence of intraprocedure hypotension. CONCLUSIONS: Dex sedation during EPSs is not associated with a reduction in PSVT inducibility. The therapeutic utility of Dex during EPS arises from the predictable sedation Dex affords but is associated with an increased incidence of intraprocedure hypotension.

Comparison of dexmedetomidine and sufentanil as adjuvants to local anesthetic for epidural labor analgesia: a randomized controlled trial.

BACKGROUND: The epidural dexmedetomidine combined with ropivacaine has been successfully used for labor analgesia. We compared the effects of dexmedetomidine and sufentanil as adjuvants to local anesthetic for epidural labor analgesia. METHODS: Eighty nulliparous women were enrolled in the double-blind study and randomly divided into two groups. Group D received 0.5 µg/mL dexmedetomidine with 0.1% ropivacaine for epidural labor analgesia, and group S (control group) received 0.5 µg/mL sufentanil with 0.1% ropivacaine for labor analgesia. Hemodynamic parameters were monitored. Pain was assessed using a visual analog scale. The onset of epidural analgesia, duration of stages of labor, Ramsay Sedation Scale, blood loss, neonatal Apgar scores, umbilical artery blood pH and adverse effects, such as respiratory depression, nausea, vomiting, pruritus, and bradycardia, were recorded. RESULTS: Compared with the control group, visual analog scale values after cervical dilation >3 cm were lower in group D (P<0.05) and first-stage labor duration was shorter in group D (378.5±52.6 vs 406.5±58.2, P<0.05). Ramsay Sedation Scale values were higher in group D compared to the control group (2.8±0.6 vs 2.4±0.5, P<0.05). No significant differences in side effects were observed between the groups. CONCLUSION: Dexmedetomidine is superior to sufentanil in analgesic effect and duration in first-stage labor during epidural analgesia when combined with 0.1% ropivacaine (www.chictr.org.cn, registration ChiCTR-OPC-16008548).

The effect of aquapuncture at Pericardium 6 (PC-6) on dexmedetomidine-induced nausea and vomiting in cats.

OBJECTIVE: To determine the effect of aquapuncture at acupuncture point Pericardium 6 (PC-6) on the incidence of dexmedetomidine-induced vomiting and nausea in cats. STUDY DESIGN: Randomized, prospective, crossover study. ANIMALS: A group of 22 cats, 14 females and eight males, aged 1-12 years and weighing 3.8-5.9 kg. METHODS: Each cat was administered treatments in random order at ≥1 week intervals. For treatment (DEX-A), cats were administered PC-6 stimulation by aquapuncture (0.25 mL/250 µg vitamin B12 injection subcutaneously at PC-6). After 30 minutes, dexmedetomidine (10 µg kg-1) was administered intramuscularly (IM). For control treatment (DEX), cats were administered only dexmedetomidine (10 µg kg-1) IM. Incidence of vomiting, number of vomiting episodes and time to first vomiting were recorded by an observer unaware of treatment allocation. At 30 minutes after dexmedetomidine administration, atipamezole (0.1 mg kg-1) was injected IM. Behavior was video recorded and later scored by two observers for clinical signs of nausea. A regression model (analysis of covariance) was used to detect the influence of aquapuncture on vomiting and nausea. Significance was set at p < 0.05. RESULTS: Of 21 cats, 18 (85%) and 16 cats (76%) vomited in DEX-A and DEX, respectively. There was no significant difference in the incidence of vomiting (p = 0.55), number of vomiting episodes (p = 0.55), mean time to vomit (p = 0.88) or nausea score (p = 0.51) between DEX-A and DEX. CONCLUSIONS AND CLINICAL RELEVANCE: PC-6 aquapuncture did not reduce the incidence of dexmedetomidine-induced vomiting or severity of nausea in cats.

Efficacy of different doses of dexmedetomidine as a rapid bolus for children: a double-blind, prospective, randomized study.

BACKGROUND: Dexmedetomidine (DEX), a highly sensitive α2-adrenoceptor agonist that possesses anxiolytic, sedative, and analgesic effects, has been documented as a preventative and treatment for emergence agitation (EA). The therapeutic should be given as a loading dose that is infused during a 10 min period, but if a rapid bolus injection is deemed to be hemodynamically appropriate, it would be a more opportune route of administration. So we studied the efficacy of different doses of DEX as a rapid bolus for children to prevent and treat EA. METHODS: One hundred patients were enrolled and randomly divided into five groups: the control group (group D1), the 0.25 µg/kg DEX group (group D2), the 0.5 µg/kg DEX group (group D3), the 0.75 µg/kg DEX group (group D4), and the 1 µg/kg DEX group (group D5). Heart rate (HR), mean blood pressure (MBP) and blood oxygen saturation (SaO2) were recorded immediately before the study drug injection (baseline) and every minute for 5 min thereafter and at the time points of the skin cut and hernial sac pull. EA and pain were assessed in the post -anesthesia care unit, and any complementary medicine and adverse events were recorded too. RESULTS: The incidence of EA was significantly decreased in group D4 and group D5 compared with D1.All groups exhibited similar baseline HR and MBP. After administered, HR and MBP were significantly decreased in all DEX group compared with group D1.In groups D3, D4 and D5, the minimal HR was decreased significantly compared with the groups D1 and duration time of minimal HR significantly prolonged in group D5, but no patient needed treatment. As the dosage increased, the recovery time was significantly prolonged. There were no significant differences in occurrence time of minimal HR, the incidence of complementary medicine and adverse events among groups. CONCLUSION: Rapid intravenous injection (IV) bolus administration of 0.75 and 1.0 µg/kg of DEX could improve the recovery profile by reducing the incidence of EA in children. Although its use resulted in a transient decreases in HR and MBP, DEX was clinically well-tolerated in children. TRIAL REGISTRATION: No. ChiCTR-IPR-17010658 . Registered 17 February 2017.

A Combination of Dexmedetomidine and Lidocaine Is a Cardiovascularly Safe Dental Local Anesthetic for Hypertensive Rats Treated With a Nonselective ß-Adrenergic Antagonist.

Hypertensive patients receiving nonselective ß-adrenergic antagonists are vulnerable to hypertension and bradycardia when injected with dental local anesthetic formulations containing epinephrine. Dexmedetomidine (DEX), an α2-adrenergic agonist, has been reported to prolong and enhance the local anesthetic effects of lidocaine. The cardiovascular effects of the DEX-lidocaine combination have not yet been investigated in the presence of nonselective ß-adrenergic antagonists. Therefore, we assessed the cardiovascular effects of the DEX-lidocaine combination in spontaneously hypertensive rats (SHR) treated with a nonselective ß-adrenergic antagonist (propranolol). We injected propranolol-treated rats with various concentrations of DEX alone, 100 µg/kg epinephrine alone, or 5 µg/kg DEX combined with 2% lidocaine and measured their blood pressure (BP) and heart rates (HR) to assess the cardiovascular effects. The BP of propranolol-treated SHR was significantly increased by treatment with 100 µg/kg epinephrine alone. The BP and HR of propranolol-treated SHR were not significantly changed by treatment with low concentrations of DEX, but they were significantly decreased by treatment with a high concentration of DEX (50 µg/kg). Moreover, there was no significant difference in the BP and HR of propranolol-treated SHR after the injection of a combination of 5 µg/kg DEX and 2% lidocaine. Thus, the DEX-lidocaine combination may be an acceptable addition to dental local anesthetic solutions from a cardiovascular standpoint for hypertensive patients receiving nonselective ß-adrenergic antagonists.

Comparison of Dexmedetomidine-Ketamine with Isoflurane for Anesthesia of Chinchillas (Chinchilla lanigera).

The objective of this study was to compare isoflurane with a combination of dexmedetomidine and ketamine, administered intramuscularly, for anesthesia in chinchillas (Chinchilla lanigera). In a prospective, complete crossover study, adult chinchillas (n = 8; age, 2 to 5 y) were anesthetized with a combination of dexmedetomidine (0.015 mg/kg IM) and ketamine (4 mg/kg IM). Atipamezole (0.15 mg/kg) was injected subcutaneously 45 min after dexmedetomidine-ketamine administration. For comparison, anesthesia also was induced and maintained with isoflurane in 100% oxygen, delivered by facemask. Anesthetic and physiologic parameters were recorded during each anesthesia, including various reflexes, heart rate, respiratory rate, body temperature, and SpO2. Food intake, fecal output, and body weight were recorded daily for 6 d after each anesthetic trial. Induction time, heart rate, respiratory rate, and body temperature did not differ significantly between the 2 anesthetic protocols. Recovery times were shorter and SpO2 was higher in animals that received isoflurane delivered in 100% oxygen. Food intake and fecal output were reduced in the dexmedetomidine-ketamine group for as long as 3 d after anesthesia, whereas isoflurane had no signifcant effect on food intake or fecal output. Both anesthetic protocols provided effective anesthesia in chinchillas. However, when anesthetized with dexmedetomidine-ketamine, chinchillas received room air and became hypoxemic. Future studies are needed to evaluate the effect of oxygen supplementation on anesthetic recovery and on the recovery of food intake and fecal output in chinchillas.

Changes in First Postoperative Night Bispectral Index After Daytime Sedation Induced by Dexmedetomidine or Midazolam Under Regional Anesthesia: A Randomized Controlled Trial.

BACKGROUND AND OBJECTIVES: Supplementation of spinal anesthesia with various sedatives is a standard protocol to alleviate patient anxiety associated with the surgical procedure. We hypothesized that, compared with dexmedetomidine, midazolam might have a subtle influence on sleep quality after surgery following elective transurethral prostatic resection (TURP) in elderly male patients. METHODS: A randomized, double-blind, controlled trial was conducted at the First Hospital of China Medical University from July 2014 to January 2015. One hundred eleven patients undergoing TURP were enrolled and received intravenous saline infusion (control group), dexmedetomidine (dexmedetomidine group), or midazolam (midazolam group) for sedation during the spinal anesthesia procedure. The intraoperative sedative state and postoperative sleep quality were evaluated using a Bispectral Index (BIS)-Vista monitor. The primary outcome was postoperative sleep quality, as measured by the BIS-Vista monitor on the first night after surgery. RESULTS: The intraoperative BIS area under the curve value was significantly lower in the dexmedetomidine group (54.1%) compared with those in the other 2 groups (control group, 94.1%; midazolam group, 77.2%).The postoperative BIS area under the curve value was highest in the dexmedetomidine group at 88.7%. The BIS sleep efficiency index showed a significant 33.1% increase in the midazolam group compared with the dexmedetomidine group. The duration of sleep in the midazolam group was 237.8 minutes longer than that in the dexmedetomidine group. CONCLUSIONS: We conclude that midazolam combined with spinal anesthesia might preserve the sleep quality of elderly male patients immediately after TURP.

Effects of Dexmedetomidine Infusion on the Recovery Profiles of Patients Undergoing Transurethral Resection.

Transurethral resection has been the gold standard in the operative management of benign prostatic hyperplasia and bladder tumor; however, it is associated with several complications that may cause patient discomfort. We evaluated the usefulness of continuous infusion of dexmedetomidine on emergence agitation, hemodynamic status, and recovery profiles in patients undergoing elective surgery by a randomized clinical trial. Sixty patients aged 30 to 80 yr who were scheduled for elective transurethral resection under general anesthesia were included in this study. Participants were randomly assigned to two groups (control group, group C; dexmedetomidine group, group D). A total of 60 male patients were enrolled in this study and randomly assigned to group C (n=30) or group D (n=30). The quality of emergence in group D was marked by a significantly lower incidence of emergence agitation than in group C (P=0.015). Patients in group D therefore felt less discomfort induced by the indwelling Foley catheter than those in group C (P=0.022). No statistically significant differences were found between the two groups with respect to side effects including bradycardia (P=0.085), hypotension (P=0.640), and postoperative nausea and vomiting (P=0.389). Our study showed that intraoperative dexmedetomidine infusion effectively reduced the incidence and intensity of emergence agitation and catheter-induced bladder discomfort without delaying recovery time and discharge time, thus providing smooth emergence during the recovery period in patients undergoing transurethral resection (Clinical Trial Registry No. KT0001683).

Vitamin C ameliorates high dose Dexmedetomidine induced liver injury.

BACKGROUND: We investigated whether vitamin C has protective effects on rat liver tissue treated with different dexmedetomidine doses. MATERIAL AND METHODS: Thirty five wistar albino rats were randomly divided into 5 groups (Control (0.9% NaCl intraperitoneally (i.p.), Dexmedetomidine 5 µg.kg(-1) (i.p.), Dexmedetomidine 5 µg.kg(-1) i.p. plus Vitamin C (100 mg.kg(-1)), Dexmedetomidine 10 µg.kg(-1) i.p. and Dexmedetomidine 10 µg.kg(-1) i.p. plus Vitamin C (100 mg.kg(-1)). Histopathological liver injury, superoxide dismutase (SOD) activity and tissue Malondialdehyde levels were investigated. RESULTS: Hepatocyte degeneration was significantly higher in D10 group than those in other study groups (p < 0.0001, p = 0.002, p < 0.0001, p = 0.005, respectively). Similarly, liver tissue sinusoidal dilatation and hepatocyte necrosis were significantly higher in D10 group than those in other groups (p < 0.0001, p < 0.0001, p = 0.002, p < 0.0001 and p < 0.0001, p = 0.046, p < 0.0001 and p = 0.002, respectively). Tissue MDA levels in D10 group were significantly higher than those in control, D5+Vit C and D10+Vit C groups (p = 0.028, p = 0.004, p = 0.031, respectively). SOD enzyme activity in D10 group was significantly lower than in control, D5+Vit C and D10+Vit C groups (p < 0.0001, p = 0.023 and p = 0.031, respectively). CONCLUSION: High dose dexmedetomidine can induce hepatic injury and oxidative stress in rats while pre-treatment with vitamin C may be effective in protecting liver tissue against this newly recognized undesirable dexmedetomidine effect (Tab. 2, Fig. 5, Ref. 30).

Effects of Dexmedetomidine Infusion on the Recovery Profiles of Patients Undergoing Transurethral Resection

Transurethral resection has been the gold standard in the operative management of benign prostatic hyperplasia and bladder tumor; however, it is associated with several complications that may cause patient discomfort. We evaluated the usefulness of continuous infusion of dexmedetomidine on emergence agitation, hemodynamic status, and recovery profiles in patients undergoing elective surgery by a randomized clinical trial. Sixty patients aged 30 to 80 yr who were scheduled for elective transurethral resection under general anesthesia were included in this study. Participants were randomly assigned to two groups (control group, group C; dexmedetomidine group, group D). A total of 60 male patients were enrolled in this study and randomly assigned to group C (n=30) or group D (n=30). The quality of emergence in group D was marked by a significantly lower incidence of emergence agitation than in group C (P=0.015). Patients in group D therefore felt less discomfort induced by the indwelling Foley catheter than those in group C (P=0.022). No statistically significant differences were found between the two groups with respect to side effects including bradycardia (P=0.085), hypotension (P=0.640), and postoperative nausea and vomiting (P=0.389). Our study showed that intraoperative dexmedetomidine infusion effectively reduced the incidence and intensity of emergence agitation and catheter-induced bladder discomfort without delaying recovery time and discharge time, thus providing smooth emergence during the recovery period in patients undergoing transurethral resection (Clinical Trial Registry No. KT0001683).

A comparison of dexmedetomidine and propofol in Patients undergoing electrophysiology study.

BACKGROUND: Dexmedetomidine provides profound levels of sedation without affecting cardiovascular and respiratory stability based on its pharmacological profile. It may be a valuable sedative for procedures with minimal to mild pain. Electrophysiology study (EP study) is a mildly painful procedure that requires conscious sedation. The authors hypothesized that dexmedetomidine would cause lower respiratory and cardiovascular depression than propofol during equal sedation level in an electrophysiology study. MATERIAL AND METHOD: The present study protocol was approved by the clinical research ethics committee at Ramathibodi Hospital. Thirty-four patients were randomly allocated into two groups to receive either dexmedetomidine or propofol for an electrophysiology study. Patients in the dexmedetomidine group received a loading dose of dexmedetomidine (0.5 mcg/kg) infused over 10 minutes followed by 0.4 mcg/kg/h. Each patient in the propofol group received propofol 1 mg/kg over 10 minutes followed by 3 mg/kg/h. All patients received pethidine (0.5 mg/kg) before the initiation of EP study. Sedation was determined using the Modified Observer's Assessment of Alertness/Sedation (MOAA/S). The Modified Observer's Assessment of Alertness/Sedation scores, hemodynamic and respiratory variables were recorded regularly during the EP study. RESULTS: Thirty-four patients were enrolled in the present study. The Modified Observer's Assessment Alertness/Sedation values were similar in both groups. Respiratory rate values with dexmedetomidine were significantly higher than those in the propofol group (p = 0.048) and the oxygen supplement in the dexmedetomidine group were significantly lower than those in the propofol group (p < 0.001). Moreover mean arterial blood pressure values of dexmedetomidine at the five and 15-minute were significantly higher than those of the propofol group (p = 0.024). No incidence of severe bradycardia or hypotension was found in both groups. CONCLUSION: The present study demonstrated that comparable sedation could be achieved by a combination of pethidine with either dexmedetomidine or propofol during EP study. Dexmedetomidine group provided more hemodynamic and respiratory stability than propofol group.

Intranasal atomized dexmedetomidine for sedation during third molar extraction.

The purpose of this study was to evaluate the intranasal use of 1.5 µg/kg atomized dexmedetomidine for sedation in patients undergoing mandibular third molar removal. Eighteen patients underwent third molar removal in two surgical sessions. Patients were randomly assigned to receive intranasal water (placebo group) or 1.5 µg/kg atomized dexmedetomidine (group D) at the first session. The alternate regimen was used during the second session. Local anaesthesia was injected 30 min after placebo/sedative administration. Pain from local anaesthesia infiltration was rated on a scale from zero (no pain) to 10 (worst pain imaginable). Sedation status was measured every 10 min by a blinded observer with a modified Observer's Assessment of Alertness/Sedation (OAA/S) scale and the bispectral index (BIS). Adverse reactions and analgesic consumption were recorded. Sedation values in group D were significantly different from placebo at 20-30 min, peaked at 40-50 min, and returned to placebo levels at 70-80 min after intranasal drug administration. Group D displayed decreased heart rate and systolic blood pressure, but the decreases did not exceed 20% of the baseline values. Intranasal administration of 1.5 µg/kg atomized dexmedetomidine is effective, convenient, and safe as a sedative for patients undergoing third molar extraction.

Effects of intravenous dexmedetomidine on low-dose bupivacaine spinal anaesthesia in elderly patients.

BACKGROUND: Dexmedetomidine (DMT) has been shown to prolong spinal anaesthesia. We evaluated the effects of intravenous DMT on low-dose bupivacaine spinal anaesthesia in elderly patients. METHODS: Fifty-one elderly patients undergoing transurethral resection of the prostate were randomized into two groups receiving either 1.0 µg/kg DMT (DMT group, n = 26) or normal saline (control group n = 25) intravenously prior to spinal anaesthesia with 1.2 ml of bupivacaine, 5 mg/ml. RESULTS: The mean time to two-segment regression (39 min vs. 78 min for cold, 41 min vs. 61 min for pinprick) and that to motor regression (23 min vs. 46 min) were longer in the DMT group than in the control group. The atropine-requiring bradycardia was more frequent in the DMT group than in the control group (24.0% vs. 3.8%). The median sedation scores (ranges) during surgery were 4 (2-6) in the DMT group and 2 (1-3) in the control group (P < 0.001). Two patients in the DMT group showed oxygen desaturation (peripheral oxygen saturation < 90%) during surgery. The duration of post-operative care unit stay was longer in the DMT group than in the control group (58 min vs. 96 min). Post-operative pain intensity was lower and the mean time to first request for post-operative analgesia was longer in the DMT group compared to the control group (6.6 h vs. 2.1 h). CONCLUSION: Intravenous DMT prolonged the duration of spinal anaesthesia and improved post-operative analgesia. However, more profound sedation with desaturation was observed with more frequent bradycardia, and delayed recovery should be considered in elderly patients.