Intraoperative Dexmedetomidine Infusion Research Articles

Effect of Different Doses of Dexmedetomidine on Stress Response and Emergence Agitation after Laparoscopic Cholecystectomy: Randomized Controlled Double-Blind Study

Background: Emergence agitation (EA) may develops during recovery from general anesthesia. It causes confusion, disorientation, and unpredictable behaviours. Surgical stress response activates the sympathetic nervous system and increase the release of catabolic hormones leading to prolonged hospital stay. Objectives: We designed this study to assess the effect of different doses of intra-operative dexmedetomidine infusion on surgical stress response, emergence agitation and postoperative outcome. Study design: A controlled double-blind study was conducted using a computer-generated randomization scheme. Setting: The study was conducted in Assiut University Hospitals, Assiut, Egypt. Methods: 90 patients scheduled for laparoscopic cholecystectomy were randomly assigned into three equal groups to receive intraoperative dexmedetomidine infusion over 20 minutes before end of surgery. Group I received 1 μg/kg, group II received 0.75 μg/kg and group III received 0.5 μg/kg. Results: We found that dexmedetomidine (0.5, 0.75 or 1 μg/kg) can decrease the incidence of EA when infused 20 minutes before skin closure in laparoscopic cholecystectomy in adults. Lower agitation scores, pain scores, cortisol and glucose levels were observed during the first 2 hours postoperatively with no serious complications. Limitations: First, we think a larger number of patients may be needed to detect better comparison between different doses of dexmedetomidine in preventing EA and monitor possible complications. Second, we did not take in mind any other preoperative predisposing factors that may affect the incidence of EA especially anxiety or smoking. Finally, we did not use any monitoring for depth of anesthesia which has an important factor in the incidence of emergence agitation. Conclusion: We conclude that low doses of dexmedetomidine infusion (0.5 μg/kg) over 20 minutes before skin closure are effective as higher doses (0.75 and 1 μg/kg) to decrease stress response and incidence of emergence agitation in laparoscopic cholecystectomy in adults with less adverse effects.

Effectiveness of transtracheal lidocaine as an adjunct to general anesthesia in providing patient immobility during total parotidectomy: A comparison with dexmedetomidine infusion.

Backgroud and Aims:Dexmedetomidine and propofol infusions are increasingly being used to ensure intraoperative patient immobility in the absence of muscle relaxants during parotidectomy. The primary aim of our study was to assess the effectiveness of transtracheal block as an adjunct to general anesthesia in providing patient immobility during total parotidectomy, as compared to dexmedetomidine infusion.Material and Methods:This prospective, randomized study was conducted in 58 patients. Group A patients received a transtracheal injection of 4 ml of 4% lidocaine before induction whereas in Group B, dexmedetomidine 1 mcg/kg was administered intravenously. Following induction and intubation, anesthesia was maintained with oxygen, nitrous oxide, and isoflurane and dexmedetomidine was administered in Group B at a rate of 0.7 mcg/kg/h. In both the groups, if the patient moved, bucked, or if there were signs of inadequate depth of anesthesia, plane of anesthesia was deepened with a bolus of propofol 0.5 mg/kg intravenously. Mann–Whitney U-test and Fisher's exact test were used for statistical analysis.Results:The number of patients who moved in the transtracheal group was significantly less as compared to dexmedetomidine group (3 vs. 11). Mean heart rates (HRs) were comparable in both groups till 10 min, but between 15 and 180 min, Group B had significantly low HR. Systolic blood pressure (SBP) was significantly high at 10 min following dexmedetomidine bolus in Group B. Though Group B showed low SBP values as compared to Group A from 10 min following induction, the difference became significant between 45 and 180 min. Changes in mean arterial blood pressures followed a similar trend as with SBP.Conclusion:Transtracheal lidocaine ensured patient immobility with hemodynamic stability during total parotidectomy with nerve stimulation studies as compared to intraoperative dexmedetomidine infusion.

Postoperative nausea and vomiting after thyroidectomy: a comparison between dexmedetomidine and remifentanil as part of balanced anesthesia.

BackgroundPostoperative nausea and vomiting (PONV) is the major complication related to general anesthesia, occurring in 60–80% of patients after thyroidectomy. The objective of this study was to compare the effects of an intraoperative dexmedetomidine infusion with remifentanil, as anesthetic adjuvants of balanced anesthesia, on PONV in patients undergoing thyroidectomy.MethodsEighty patients scheduled for thyroidectomy were randomized into the following two groups: 1) The dexmedetomidine group (Group D), who received an initial loading dose of dexmedetomidine (1 µg/kg over 10 min) during the induction of anesthesia, followed by a continuous infusion at a rate of 0.3–0.5 µg/kg/h; 2) the remifentanil group (group R), who received remifentanil at an initial target effect site concentration of 4 ng/ml during the induction of anesthesia, followed by a target effect site concentration of 2–3 ng/ml. PONV was assessed during the first 24 hours in 2 time periods (0–2 h and 2–24 h). The pain intensity, sedation score, extubation time, and hemodynamics were also assessed.ResultsDuring the 2 time periods, the incidence and severity of PONV in group D were significantly lower than in group R. In addition, the need for rescue antiemetics was significantly lower in group D than in group R. The effect of dexmedetomidine on postoperative pain relief (2–24 h) was superior to that of remifentanil. The hemodynamics were similar in both groups, whereas eye opening and extubation time were delayed in group D.ConclusionsAdjuvant use of intraoperative dexmedetomidine infusion may be effective for the prevention of PONV.

Shorter postanesthesia care unit stay with dexmedetomidine infusion during laparoscopic bariatric surgery: a randomized controlled trial

Introduction Lesser narcotics use during laparoscopic bariatric surgery is needed to decrease the impact on respiratory parameters and reduce analgesic requirements after surgery. Using dexmedetomidine has a role in perioperative pain control in obese patients’ recovery in postanesthetic care unit (PACU) and hospital stay. In this study, we hypothesized that dexmedetomidine would delay and decrease opioid requirements during surgery, promoting less time in the PACU and faster, safer recovery. Patients and methods After obtaining ethics committee approval, informed consent to participate in this study was obtained from 56 patients who were scheduled for planned laparoscopic bariatric surgery. Patients were randomly divided into two groups − group D (n=28) received dexmedetomidine 1 µg/kg loading for 10 min and 0.4 µg/kg/h maintenance until extubation, and group N (n=28) received normal saline (placebo) at the same volume and rate. PACU stay time, the total amount of intraoperative fentanyl used, recovery profile, pain score, and the total amount of pethidine used postoperatively were measured. Results The dexmedetomidine group showed significant decrease in intraoperative and postoperative hemodynamics, shorter recovery time, and shorter stay in PACU. Perioperative narcotic use, intraoperative fentanyl use, visual analog scale scores, PACU pethidine dose in the first hour, and total pethidine dose on the first day were significantly less in the dexmedetomidine group. Patient satisfaction at discharge regarding pain management was less in the control group. Conclusion Intraoperative dexmedetomidine infusion with its opioid-sparing effect enhanced recovery in this study population of morbidly obese patients undergoing laparoscopic bariatric surgery with minimal side-effects.

Multimodal analgesia with pregabalin and dexmedetomidine in morbidly obese patients undergoing laparoscopic sleeve gastrectomy: A prospective randomized double blind placebo controlled study

Background and objectivesSleeve gastrectomy has become a popular and effective treatment for morbidly obese patients. The aim of this prospective randomized study was to assess the efficacy of multimodal analgesia using pregabalin and dexmedetomidine in morbidly obese patients undergoing laparoscopic sleeve gastrectomy.Materials and methodsAfter ethical approval 60 American Society of Anesthesiologists (ASA) physical status II patients were enrolled in this study and allocated randomly into 2 groups: group A received 75 mg oral pregabalin 2 h before surgery and dexmedetomidine infusion 0.4 μg/kg/h and group B (control group) received placebo capsule 2 h before surgery and saline infusion intraoperatively. Intraoperative fentanyl consumption, hemodynamics and postoperative opioid consumption, pain scores, level of sedation and any side effects were evaluated.ResultsThere was a significant decrease in heart rate, mean arterial blood pressure, pain score, intraoperative fentanyl use, postoperative morphine consumption and nausea verbal rating scale in group A compared to group B. There was a significant increase in sedation score in group A compared to group B.ConclusionsThe combination of preoperative oral pregabalin and intraoperative dexmedetomidine infusion decreased intraoperative fentanyl use and ensured postoperative better pain control and less postoperative opioid consumption.

Dexmedetomidine during total knee arthroplasty performed under spinal anesthesia decreases opioid use: a randomized-controlled trial

It remains unclear whether the opioid-sparing effects of dexmedetomidine seen in patients undergoing general anesthesia are reproducible in patients undergoing spinal anesthesia. We hypothesized that the administration of intravenous dexmedetomidine for sedation during total knee arthroplasty under spinal anesthesia would decrease postoperative morphine consumption in the first 24 hr following surgery. We conducted this prospective double-blind randomized-controlled trial in 40 patients (American Society of Anesthesiologists physical status I-III) undergoing total knee arthroplasty with a standardized spinal anesthetic. Patients were randomized to receive either a dexmedetomidine loading dose of 0.5 µg·kg(-1) over ten minutes, followed by an infusion of 0.5 µg·kg·hr(-1) for the duration of the surgery, or a normal saline loading dose and an infusion of an equivalent volume. The primary outcome was the consumption of morphine delivered via patient-controlled analgesia in the first 24 hr following surgery. The mean (SD) cumulative morphine at 24 hr in the dexmedetomidine group was 29.2 (11.2) mg compared with 61.2 (17.2) mg in the placebo group (mean difference, 32.0 mg; 95% confidence interval, 22.7 to 41.2; P < 0.001). In the dexmedetomidine group, there was a delay in the time to first analgesic request (P = 0.003) and a reduction in the mean morphine use at six and 12 hr following surgery (both P < 0.001). Dexmedetomidine was associated with a significant decrease in morphine use in the first 24 hr following total knee arthroplasty. Our study shows that an intraoperative infusion of dexmedetomidine for sedation in patients receiving spinal anesthesia can produce postoperative analgesic effects. This offers another potential adjunct in the multimodal pain management of these patients. This trial was registered at ClinicalTrials.gov (identifier NCT02026141).

Dexmedetomidine infusion versus fentanyl for analgesia and prevention of emergence agitation and delirium in children undergoing adenotonsillectomy

Background This randomized controlled study aimed to evaluate whether an intraoperative infusion of dexmedetomidine would be a safe and effective substitute to fentanyl intraoperatively, and whether it would be effective in reducing the incidence and severity of emergence agitation and delirium in children undergoing adenotonsillectomy. Patients and methods This study was conducted on 70 pediatric patients, aged 3–7 years, of both sexes, of ASA I and II, who were scheduled for elective adenotonsillectomy. The patients were randomly assigned to two groups: group D (dexmedetomidine infusion group; 35 patients) received intravenous dexmedetomidine (2 μg/kg) over 10 min, followed by 0.7 μg/kg/h until 5 min before the end of the surgery, and group F (intravenous fentanyl group; 35 patients) received intravenous fentanyl 1 μg/kg as a bolus. No premedication was given to any of the patients. The number of patients in each group who needed intraoperative fentanyl, the fentanyl dose, time of administration of fentanyl, duration of surgery and anesthesia, and the time to awakening were recorded. Pain was evaluated using the objective pain scale score in the postanesthesia care unit (PACU), which was managed with rescue intravenous pethidine. Emergence agitation was evaluated in the PACU using two scales: the Pediatric Anesthesia Emergence Delirium scale and the five-point agitation scale described by Cole. Results The time to awakening in group D was significantly shorter compared with that in group F (P Conclusion Dexmedetomidine is a safe and effective analgesic substitute to fentanyl intraoperatively and reduces analgesic requirements postoperatively. It is also effective in reducing the incidence and severity of emergence agitation and delirium in children undergoing adenotonsillectomy.

Lidocaine versus dexmedetomidine infusion in diagnostic laparoscopic gynecologic surgery: a comparative study

Background The aim of this study was to assess the effectiveness of intraoperative lidocaine versus dexmedetomidine infusion on hemodynamic stability during pneumoperitoneum, as well as the recovery profile of diagnostic laparoscopic gynecologic surgeries. Patients and methods A total of 60 female patients of American Society of Anesthesiologist (ASA) physical status I were included in the study and divided into two groups: group L and group D. Group L received lidocaine hydrochloride 2%, and group D received dexmedetomidine hydrochloride. The hemodynamic changes during pneumoperitoneum as well as the recovery profile (postoperative sedation, pain scores, and analgesic requirements) were recorded. Results During pneumoperitoneum, group D patients showed a statistically significant decrease in mean heart rate compared with group L patients. However, the mean systolic blood pressure, diastolic blood pressure, and mean blood pressure in group L patients showed statistically and clinically nonsignificant changes compared with those of group D patients. As regards the recovery profile, group D patients recorded a significantly higher median sedation score compared with group L patients, and the postoperative pain scores were significantly better in group L than in group D patients after 30 min, 1 h from arrival at the postanesthesia care unit, and at 2 h in the ward. However, this resulted in a statistically nonsignificant number of patients requiring pethidine in the postanesthesia care unit, as well as statistically nonsignificant total pethidine requirements of less than 50 mg. Conclusion Lidocaine offers hemodynamic stability during pneumoperitoneum, as well as a decrease in the intensity of postoperative pain with opioid sparing, offering a less sedated patient than dexmedetomidine during day-case diagnostic laparoscopic gynecologic surgery.

The Opioid-sparing Effect of Intraoperative Dexmedetomidine Infusion After Craniotomy.

We conducted a randomized trial to evaluate the opioid-sparing effect of an intraoperative infusion of dexmedetomidine (DEX) after craniotomy. Sixty adult patients scheduled for craniotomy were divided randomly into group A (DEX infusion at 0.5 μg/kg/h for 10 min and then adjusted to 0.2 to 0.5 μg/kg/h from tracheal intubation to incision suturing) and group B (0.9% saline infusion). Additional intravenous injections and patient-controlled analgesia with morphine were used to control postoperative pain for verbal Numerical Rating Scale scores >4. Cumulative morphine consumption, Numerical Rating Scale pain score, and the Ramsay Sedation Scale score were evaluated at 1, 2, 4, 6, 8, 12, and 24 hours; the incidence of postoperative nausea and vomiting, agitation, and respiratory depression were recorded at 24 hours after surgery. Postoperative pain scores within 12 hours and Ramsay Sedation Scale scores within 6 hours of surgery were both significantly lower in group A than in group B (P<0.001). Patients in group A required 54.4%, 43.3%, and 31.4% less cumulative morphine consumption during the first 4, 12, and 24 hours, respectively. No patient in group A and 5 patients in group B presented agitation within 1 hour after surgery. Three patients in group A and 9 patients in group B showed pruritus (P<0.001). An intraoperative infusion of DEX reduced cumulative morphine consumption and adverse effects after craniotomy.

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).

Effect of Intraoperative and Postoperative Infusion of Dexmedetomidine on the Quality of Postoperative Analgesia in Highly Nicotine-Dependent Patients After Thoracic Surgery: A CONSORT-Prospective, Randomized, Controlled Trial.

Smoking is one of the most common addictions in the world. Nicotine inhalation could increase the risk of cardiorespiratory diseases. However, the solution that improved postoperative analgesia for highly nicotine-dependent patients undergoing thoracic surgery has not been specifically addressed.This CONSORT-prospective, randomized, double-blinded, controlled trial investigated the efficacy of combination of dexmedetomidine and sufentanil for highly nicotine (Fagerstrom test of nicotine dependence ≥6)-dependent patients after thoracic surgery.One hundred seventy-four male patients who underwent thoracic surgery were screened between February 2014 and November 2014, and a total of forty-nine were excluded. One hundred thirty-two highly nicotine-dependent male patients who underwent thoracic surgery and received postoperative patient-controlled intravenous analgesia were divided into 3 groups after surgery in this double-blind, randomized study: sufentanil (0.02 μg/kg/h, Group S), sufentanil plus dexmedetomidine (0.02 μg/kg/h each, Group D1), or sufentanil (0.02 μg/kg/h) plus dexmedetomidine (0.04 μg/kg/h) (Group D2). The patient-controlled analgesia (PCA) program was programmed to deliver a bolus dose of 2 ml, with background infusion of 2 ml/h and a lockout of 5 min, 4-hour limit of 40 ml, as our retrospective study. The primary outcome measure was the cumulative amount of self-administered sufentanil; the secondary outcome measures were pain intensity (numerical rating scale, NRS), level of sedation (LOS), Bruggrmann comfort scale (BCS), functional activity score (FAS), and concerning adverse effects.The amount of self-administered sufentanil were lower in group D2 compared with S and D1 groups during the 72 hours after surgery (P < 0.05), whereas the total dosage and dosage per body weight of sufentanil were significantly lower in D1 group than that of S group only at 4, 8, and 16 hours after surgery (P < 0.05). Compared with S group, the NRS scores at rest at 1, 4, and 8 hours after surgery and with coughing at 4, 8, 16, and 24 hours after surgery were significantly lower in D2 group (P < 0.05). However, compared with D1 group, the NRS scores both at rest and with coughing at 4 and 8 hours after surgery were significantly lower in D2 group (P < 0.05). The NRS scores both at rest and with coughing show that there were no significant differences between D1 group and S group at each time point after surgery (P > 0.05). LOS of group D2 was higher than S and D1 groups at 1 hour after surgery (P < 0.05), BCS of group D2 was higher than S and D1 groups at 4, 8, and 16 hours after surgery (P < 0.05), and FAS of group D2 was higher than S and D1 groups at 48 and 72 hours after surgery (P < 0.05). The number of rescue analgesia during 72 hours after surgery in D2 group was lower than S and D1 groups (P < 0.05). There were no significant differences among the 3 groups in terms of baseline clinical characteristics and postoperative adverse effects except for itching (P > 0.05).Among the tested patient-controlled analgesia options, the addition of dexmedetomidine (0.04 μg/kg/h) and sufentanil (0.02 μg/kg/h) showed better analgesic effect and greater patient satisfaction without other clinically relevant side effects for highly nicotine-dependent patients during the initial 72 hours after thoracic surgery.Trial Registration: chictr.org (ChiCTR-TRC-14004191).

Cerebral oxygen saturation monitoring during hypotensive anesthesia in shoulder arthroscopy: A comparative study between dexmedetomidine and esmolol

BackgroundBeach chair position (BCP) is used in arthroscopic shoulder operations for its advantages. The BCP together with deliberate hypotension used to decrease intraoperative blood loss during arthroscopic shoulder procedures, this may have risk to cause postoperative neurological insults. Dexmedetomidine and esmolol are used to induce deliberate hypotension. Near-infrared spectroscopy (NIRS) provides a non-invasive technique of continuous monitoring of regional cerebral tissue oxygen saturation (rScO2). In this study we evaluate the prevalence of rScO2 during hypotensive anesthesia induced by intra-operative infusion of either dexmedetomidine or esmolol in patients undergoing elective arthroscopic shoulder surgery in the BCP.Patients and methodsFifty patients scheduled for elective arthroscopic shoulder surgery under general anesthesia with hypotensive technique in BCP, randomly assigned into two equal groups, dexmedetomidine group (D Group) and esmolol group (E Group) according to the drug used for deliberate hypotension. MAP, HR, BIS and rScO2 were recorded before induction of anesthesia T0, post-induction of anesthesia T1 as baseline, 5 min after BCP T2, 5 min after starting the studied drug T3, 30 min T4, 60 min T5, 90 min T6, 5 min after stopping the studied drug T7, 5 min after return to supine T8 and after extubation T9.ResultsIn D group there was significant decrease in Lt.rsco2 and Rt.rsco2, at T2 to T7 compared to T1. In E group there was significant decrease in Lt.rsco2 and Rt.rsco2 at T2, to T7 compared to T1. In D group two patients had CDEs compared to five patients in E group.ConclusionIn patients undergoing shoulder arthroscopic surgery under general anesthesia, the BCP significantly decreases rScO2, with further slight decrease of rScO2 with dexmedetomidine and esmolol induced hypotension with no affection of postoperative cognitive function with both drugs. Dexmedetomidine and esmolol are safe drugs with better safety of dexmedetomidine over esmolol.

Ultrasound-guided transversus abdominis plane block versus dexmedetomidine infusion in open ovarian cystectomy: Analgesic efficacy and effect on stress response

Background Ultrasound (US)-guided transversus abdominis plane (TAP) block has been proven to be an effective method of providing postoperative analgesia in laparotomy. Dexmedetomidine has sedative, analgesic, sympatholytic, and amnestic properties. In the present study, we evaluated the analgesic efficacy and the attenuation of stress surgical response of US-guided TAP block in comparison with dexmedetomidine infusion in patients undergoing open ovarian cystectomy in a randomized, double-blinded clinical study. Patients and methods A total of 60 patients were randomly assigned into two groups (30 in each) to be administered, before skin incision, either a combination of general anesthesia with a US-guided TAP block (TAP group), or an intraoperative intravenous infusion of dexmedetomidine (DEX group). In the DEX group, loading dose of 1 μg/kg of dexmedetomidine was infused over 10 min, followed by infusion of 0.2-0.6 μg/kg/h. Measurements included hemodynamics, stress hormones, pain score, time of first analgesia, and amount of pethidine during the first 24 h postoperative. Results In the DEX group, there was a significant decrease in heart rate (HR) at 45, 60, and 90 min after surgical incision in comparison with preoperative HR. In the TAP group, there was a significant decrease in HR at 60 and 90 min after surgical incision in comparison with preoperative HR. In the DEX group, there was a significant decrease in mean arterial pressure at 30, 45, 60, and 90 min after surgical incision in comparison with preoperative mean arterial pressure. The DEX group had shown a statistically significant increase with regard to change in the blood level of stress hormones 12 and 24 h postoperative in comparison with the preoperative values. There was a highly significant increase in postoperative pethidine supplementation in the DEX group than in the TAP group. There was a significant difference with regard to time of the first postoperative request of analgesia in the DEX group than in the TAP group. Conclusion In open ovarian cystectomy, US-guided TAP block was comparable to dexmedetomidine infusion with regard to intraoperative hemodynamic stability and opioid requirement without change in stress response hormones. However, TAP block provided superior analgesia when compared with dexmedetomidine infusion up to 24 h postoperatively.

Efficacy of intraoperative dexmedetomidine infusion on visualization of the surgical field in endoscopic sinus surgery.

BackgroundIn endoscopic sinus surgery, visualization of the surgical field is a major concern, as surgical bleeding is the cause of many complications. The purpose of this study was to compare the effects of dexmedetomidine and remifentanil on the visualization of the surgical field in endoscopic sinus surgery.MethodsForty-three patients were prospectively enrolled and randomly allocated to the dexmedetomidine or remifentanil group and general anesthesia was induced and maintained using a propofol target-controlled infusion. In the dexmedetomidine group, dexmedetomidine was loaded for 5 min and a continuous infusion was administered. In the remifentanil group, a remifentanil target-controlled infusion was used. After completion of the operation, the satisfaction with the visualization of the surgical field was assessed on a numeric rating scale, from 0 (= worst) to 10 (= best). The mean blood pressure, heart rate, recovery profiles, and postoperative pain score were recorded.ResultsSatisfaction score for visualization by numeric rating scale was not significantly different between the two groups (P = 0.95). There were no differences in the mean blood pressure and heart rate. The extubation time was significantly shorter in the dexmedetomidine group (8.4 ± 1.8 min) than in the remifentanil group (11.9 ± 5.4 min) (P = 0.04). Except for the extubation time, the recovery profiles of the two groups were comparable.ConclusionsContinuous infusions of dexmedetomidine provide a similar visualization of the surgical field and hemodynamic stability as remifentanil target-controlled infusions in patients undergoing endoscopic sinus surgery.

The effect of dexmedetomidine on intraocular pressure increase in patients during robot-assisted laparoscopic radical prostatectomy in the steep Trendelenburg position.

This study was to evaluate the effect of intraoperative continuous infusion of dexmedetomidine on intraocular pressure (IOP) in patients undergoing robot-assisted laparoscopic radical prostatectomy (RALRP) in the steep Trendelenburg (ST). Sixty-eight patients were randomly divided into two groups. The dexmedetomidine group (Group D, n=34) received a continuous infusion of dexmedetomidine at a rate of 0.4 μg kg(-1) hour(-1) from the induction of anesthesia until the end of the ST position, while the control group (Group C, n=34) received an equal volume of physiologic saline at the same rate under conventional general anesthesia with sevoflurane and remifentanil. IOP was measured at 11 predefined time points for all patients. Significant differences in IOP were detected between the two groups by a linear mixed model analysis (p<0.001). The highest mean IOP was 19.9±5.0 mm Hg in Group D and 25.7±5.0 mm Hg in Group C; both were measured 60 minutes after the patients had been placed in the ST position. No significant between-group differences in ocular perfusion pressure, mean blood pressure, or heart rate were observed between the two groups. No ocular or other complications were noted. Intraoperative continuous infusion of dexmedetomidine may help alleviate IOP increase in patients undergoing RALRP in the ST position.

The effect of Dexmedetomidine on the incidence of postoperative cognitive dysfunction in elderly patients after prolonged abdominal surgery

BackgroundPostoperative cognitive dysfunction (POCD) in elderly patients is a common complaint after prolonged surgeries. In the present study, we aimed to investigate the effect of intraoperative infusion of Dexmedetomidine on POCD.Methods50 patients aged more than 60 years old undergoing elective abdominal surgery expected to last more than 2 hours were randomized into 2 groups of 25 patients each: those receiving Dexmedetomidine at a dose of 0.4 μg/kg/h, group (A) and those receiving 0.9% normal saline as placebo group (B). All patients underwent neuropsychometric tests (Montreal cognitive assessment and Stroop color word interference tests) the day before the surgery and 24 h after the surgery, and one week postoperatively.ResultsThe use of Dexmedetomidine as an adjuvant during Sevoflurane anesthesia did not have significant effect on protection against POCD in one day and one week postoperatively. The anesthetic and analgesic sparing effect of Dexmedetomidine was significantly proved by lower Sevoflurane need and significant lesser amount of total 24 hours postoperative Fentanyl requirements, but with significant prolonged extubation and orientation times in Dexmedetomidine group than placebo group.ConclusionsThe findings of this pilot study suggest that intraoperative use of Dexmedetomidine as an adjuvant in major surgery in elderly patients was not associated with significant protection against POCD.

Comparing the Effects of Oral Clonidine Premedication With Intraoperative Dexmedetomidine Infusion on Anesthetic Requirement and Recovery From Anesthesia in Patients Undergoing Major Spine Surgery

Clonidine, an α2 agonist, has been used in anesthesia for many years to provide sedation, anxiolysis, analgesia, controlled hypotension, and to provide opioid-sparing anesthesia. Recently, there has been a great interest in using the newer α2 agonist, dexmedetomidine, because of its more selectivity toward α2 adrenoreceptors. We compared the effects of clonidine with dexmedetomidine on anesthetic requirement and recovery from anesthesia. Seventy-four patients undergoing major spine surgery were randomly allocated to receive either oral clonidine premedication followed by an intraoperative saline infusion (group A) or placebo premedication followed by dexmedetomidine infusion in the intraoperative period (group B). Standard anesthesia protocols were followed for induction and maintenance. Heart rate, blood pressure, and end-tidal concentrations of isoflurane were noted every 15 minutes after proning. Hypertensive responses were treated with bolus doses of propofol and fentanyl. Hypotensive episodes were treated with bolus doses of ephedrine or phenylephrine. Primary outcomes were the comparisons of the effect of these 2 drugs on anesthetic requirement and recovery from anesthesia. Secondary outcomes were the comparisons of the hemodynamic response, intraoperative analgesic requirement, and blood loss during surgery. Demographic data, duration of surgery, total dose of fentanyl and propofol requirement, blood loss, and the recovery time were comparable between the 2 groups. Both drugs reduced the isoflurane requirement during surgery. However, the reduction was more and statistically significant with dexmedetomidine compared with clonidine group at 1 and 2 hours after proning (P=0.001, 0.039 at 1 and 2 h). Both drugs are equally effective in controlling the hemodynamics, and the number of episodes of hypotension, hypertension, and bradycardia were comparable between the 2 groups. Both clonidine and dexmedetomidine have anesthetic-sparing effect; however, it was more with dexmedetomidine than with clonidine. Recovery from isoflurane anesthesia was similar between both groups. Both are equally effective in controlling the hemodynamic response and reducing the blood loss during spine surgery.

Efficacy of Intraoperative Dexmedetomidine Infusion on Emergence Agitation and Quality of Recovery After Nasal Surgery

Abstract Background Emergence agitation is common after nasal surgery. We investigated the effects of intraoperative dexmedetomidine infusion on emergence agitation and quality of recovery after nasal surgery in adult patients. Methods One hundred patients undergoing nasal surgery were randomized into two groups. The dexmedetomidine group (Group D, n=50) received dexmedetomidine infusion at a rate of 0.4 μg kg−1 h−1 from induction of anaesthesia until extubation, while the control group (Group C, n=50) received volume-matched normal saline infusion as placebo. Propofol (1.5–2 mg kg−1) and fentanyl (1 μg kg−1) were used for induction of anaesthesia, and desflurane was used for maintenance of anaesthesia. The incidence of agitation, haemodynamic parameters, and recovery characteristics were evaluated during emergence. A 40-item quality-of-recovery questionnaire (QoR-40) was provided to patients 24 h after surgery. Results The incidence of agitation was lower in Group D than Group C (28 vs 52%, P=0.014). Mean arterial pressure and heart rate were more stable in Group D than in Group C during emergence (P Conclusions Intraoperative infusion of dexmedetomidine provided smooth and haemodynamically stable emergence. It also improved quality of recovery after nasal surgery.

The effect of dexmedetomidine on phosphatidylinositol 3 kinase/protein kinase B signal pathway during perioperative period in patients with meningioma

Objective To evaluate the effect of dexmedetomidine（Dex） on Phosphatidylinositol 3 kinase （PI3K） and protein kinase B（PKB/Akt） concentration during perioperative period in patients with meningioma. Methods Forty-five ASAⅡor Ⅲ patients with meningioma scheduled for elective intracranial tumor recection were randomly divided into 3 groups（n=15）： control group（group C）,low-dose Dex group 0.2 μg·kg-1·h-1（group D1）, high dose Dex group 0.5 μg·kg-1·h-1（group D2）. Dex was intravenously infused 10 min before induction at the dose of 1 μg/kg, followed by constant speed infusion at 0.2 μg·kg-1·h-1 and 0.5 μg·kg-1·h-1 in group D1 and D2 respectively until 30 min before the end of the operation. Group C received the same volume of saline. Bispectral index（BIS） was maintained at 40-49. Venous blood samples were taken for determination of serum concentrations of Akt and PI3K respectively at the time before induction（T1）, removal of tumor（T2）, extubation（T3） and 24 h after operation（T4）. Blood samples were also collected from radial artery and jugular venous bulb for blood gas analysis to calculate the arterial oxygen content（CaO2）,cerebral arterial venous oxygen content difference cerebral arterial venous oxygen content difference（Da-jvO2） and cerebral extraction of oxygen（CEO2）. Results Compared with T1, the serum concentration of Akt and PI3K and CEO2 significantly increased at T2-T4 in the all groups（P〈0.05）. There was significant difference between group C and group D2 in the concentration of PI3K and Akt at T2-T4（P〈0.05）, PI3K in group C were[（5.9±0.5）,（6.8±0.6）,（8.2±0.5） μg/L], while that of group D2 were[（5.5±0.4）,（6.3±0.5）,（7.1±0.6） μg/L]respectively at T2-T4. Akt in serum in group C were[（0.401±0.032）,（0.482±0.050）,（0.593±0.058） μg/L], while that of group D2 were[（0.351±0.024）,（0.414±0.023）,（0.472±0.033） μg/L] respectively at T2-T4. There was significant difference among the three groups in CEO2 at T2-T3（P〈0.05）, CEO2 in group C were[（0.36±0.03）%,（0.34±0.03）%],while that of group D1 were[（0.33±0.04）%,（0.30±0.04）%], and group D2 were[（0.32±0.04）%,（0.26±0.04）%] respectively at T2-T3. Conclusions Intraoperative infusion of dexmedetomidine may play a protective effect on patients with meningioma. The mechanism may be associated with lowering plasma PI3K and Akt and cerebral oxygen uptake rate. Key words: Dexmedetomidine; Neuroprotection; Meningioma; Cerebral extraction of oxygen

Low-Dose Dexmedetomidine Reduces Emergence Agitation after Desflurane Anaesthesia in Children Undergoing Strabismus Surgery

PurposeEmergence agitation (EA) is frequently observed in children undergoing general anaesthesia. This study tested whether the addition of an intra-operative low-dose infusion of dexmedetomidine to fentanyl treatment reduced the incidence of emergence delirium following desflurane anesthesia in children undergoing strabismus surgery.Materials and MethodsA total of 96 children (1-5 years old) undergoing strabismus surgery were enrolled. Anaesthesia was induced with propofol and maintained with desflurane. After induction, fentanyl (1 µg/kg) was administered to all children. During surgery, patients were infused with 0.2 µg/(kg·h)-1 dexmedetomidine (Group FD, n=47) or normal saline (Group F, n=47). Postoperative objective pain score (OPS), Paediatric Agitation and Emergence Delirium (PAED) score, and EA score were documented every 10 minutes in the post-anaesthesia care unit.ResultsThere were no significant differences between the two groups in demographic characteristics and haemodynamic changes. The mean values of maximum EA, maximum PAED, and maximum OPS score were significantly lower in Group FD than in Group F at 0, 10, and 20 minutes after arrival at the post-anaesthesia care unit (p<0.001). The frequency of fentanyl rescue was lower in Group FD than in Group F (p<0.001). The incidence of severe EA was significantly lower in Group FD than in Group F (12.8% vs. 74.5%, p<0.001).ConclusionIntra-operative low-dose infusion of dexmedetomidine in addition to fentanyl reduces EA following desflurane anaesthesia in children undergoing strabismus surgeries.