Aytaç Yücel

A Comparison of the Sedative, Hemodynamic, and Respiratory Effects of Dexmedetomidine and Propofol in Children Undergoing Magnetic Resonance Imaging

We compared the sedative, hemodynamic, and respiratory effects of dexmedetomidine and propofol in children undergoing magnetic resonance imaging procedures. Sixty children were randomly distributed into two groups: The dexmedetomidine (D) group received 1 &mgr;g/kg initial dose followed by continuous infusion of 0.5 &mgr;g · kg−1 · h−1 and a propofol group (P) received 3 mg/kg initial dose followed by a continuous infusion of 100 &mgr;g · kg−1 · min−1. Inadequate sedation was defined as difficulty in completing the procedure because of the childs movement during magnetic resonance imaging. Mean arterial pressure (MAP), heart rate, peripheral oxygen saturation, and respiratory rate (RR) were recorded during the study. The onset of sedation, recovery, and discharge time were significantly shorter in group P than in group D. MAP, heart rate, and RR decreased during sedation from the baseline values in both groups. MAP and RR were significantly lower in group P than in group D during sedation. Desaturation was observed in four children of group P. Dexmedetomidine and propofol provided adequate sedation in most of the children. We conclude that although propofol provided faster anesthetic induction and recovery times, it caused hypotension and desaturation. Thus, dexmedetomidine could be an alternative reliable sedative drug to propofol in selected patients.

Control of shivering during regional anaesthesia: prophylactic ketamine and granisetron

Background:  The aim of the present study was to compare placebo, ketamine, granisetron and a combination of ketamine and granisetron in the prevention of shivering caused by regional anaesthesia.

Effect of dexmedetomidine on bleeding during tympanoplasty or septorhinoplasty

Background and objective: The aim of this study was to evaluate the efficacy of dexmedetomidine, an &agr;2‐adrenoceptor agonist, on intraoperative bleeding, anaesthetic drug requirement and postoperative pain. Methods: Forty patients scheduled for elective tympanoplasty and septorhinoplasty operations under general anaesthesia were included in the study. The patients were randomly assigned to receive either a dexmedetomidine 1 &mgr;g kg−1 bolus 10 min before induction of anaesthesia plus 0.5 &mgr;g kg−1 h−1 infusions during maintenance or placebo. Mean arterial pressure was maintained between 60 and 80 mmHg. Perioperative mean arterial pressure, heart rate, time to extubation and time to awakening were recorded. Bleeding during surgery was assessed by the surgeon, blinded to the study drugs, both intraoperatively and postoperatively as a final personal opinion about the whole surgical process. Results: The heart rate and mean arterial pressure were significantly lower during induction, operation and extubation in the dexmedetomidine group (P < 0.05). Blood losses were lower in the dexmedetomidine group (P < 0.05). Propofol dose required for induction, and fentanyl and isoflurane consumption were significantly reduced in the dexmedetomidine group (P < 0.05). The total amounts of nitroglycerin and meperidine used were higher in the control group (P < 0.05). Conclusions: Dexmedetomidine decreased bleeding, postoperative analgesic requirements and intraoperative anaesthetic requirements and was associated with more stable haemodynamic responses to anaesthesia. We conclude that dexmedetomidine is a useful adjuvant to decrease bleeding when a bloodless surgical field is requested.

The effects of dexmedetomidine on liver ischemia–reperfusion injury in rats

BACKGROUND Ischemia-reperfusion (IR) injury of the liver may cause various types of damage to hepatic tissues. It can affect the prognosis of patients and the success of an operation. Dexmedetomidine is a selective α2 receptor agonist. We investigated whether dexmedetomidine provides protection against IR-induced liver injury in rats. METHODS Forty rats were divided equally into four groups. In group 1, the liver was manipulated after the laparotomy, and no occlusion of the vessels of the liver was performed. In group 2, once the abdomen was opened, 60 min of ischemia and 60 min of reperfusion were applied according to the segmental hepatic ischemia model. In group 3, 10 μg/kg of dexmedetomidine was injected into the peritoneal cavity 30 min before ischemia. In group 4, 100 μg/kg of dexmedetomidine was injected into the peritoneal cavity 30 min before ischemia. Further procedures in groups 3 and 4 were the same as those of group 2. After the experiment was completed, the rats were killed. Liver tissues were removed and stored until biochemical and histologic assessments were performed. RESULTS The malondialdehyde level in group 2 was higher than that of groups 1, 3, and 4 (P = 0.001, P = 0.000, and P = 0.000, respectively). Superoxide dismutase, catalase, and glutathione levels in group 2 were lower than those in group 1 (P = 0.001, P = 0.027, and P = 0.014, respectively). Superoxide dismutase and catalase levels in group 4 were higher than those in group 2 (P = 0.002 and P = 0.000, respectively). GSH levels in groups 3 and 4 were higher than those in group 2 (P = 0.049 and P = 0.006, respectively). A lower glutathione peroxidase level was detected in groups 2 and 3 than that in group 1 (P = 000). Group 4 demonstrated an increase in glutathione peroxidase levels compared with group 3 (P = 0.014). The histologic injury scores in groups 2-4 were higher than those in group 1 (P = 0.003, P = 0.002, and P = 0.001, respectively). However, the histologic injury scores were lower in groups 3 and 4 than those in group 2 (P = 0.003 and P = 0.002, respectively). CONCLUSIONS This study showed that dexmedetomidine may protect the liver against IR injury in rats.

Pain, fentanyl consumption, and delirium in adolescents after scoliosis surgery: dexmedetomidine vs midazolam

The study aim was to compare the efficacy of dexmedetomidine vs midazolam for sedation during the early postoperative period in adolescents who underwent scoliosis surgery.

Effects of 2 Different Doses of Pregabalin on Morphine Consumption and Pain After Abdominal Hysterectomy: A Randomized, Double-Blind Clinical Trial

BACKGROUND Pregabalin has a similar pharmacologic profile to that of its developmental predecessor gabapentin but has shown greater analgesic activity in rodent models of neuropathic pain. OBJECTIVE The objective of the study was to compare the effects of 2 different doses of pregabalin and placebo on postoperative pain and morphine consumption. METHODS Ninety patients who underwent abdominal hysterectomy were included in the study and randomly divided into 3 groups in a doubled-blinded manner. They were given 150 mg of pregabalin (group P300, n = 30), 300 mg of pregabalin (group P600, n = 30), or placebo capsules (group C, n = 30) 4 hours before the induction of anesthesia; they received a second dose of the drug 12 hours postoperatively. Morphine consumption, nausea, and vomiting, visual analogue scale-pain intensity (VAS-PI), sedation scores, and dissatisfaction scores were recorded in the postanesthesia care unit (PACU) and at 2, 4, 6, and 24 hours after operation. RESULTS Morphine consumption at 24 hours was 40.80 (3.42) mg, 33.79 (5.77) mg, and 46.97 (6.67) mg in groups P300, P600, and C, respectively (P < 0.001). VAS-PI scores at movement and at rest in the PACU and at 2, 4, and 6 hours decreased in group P600 (P < 0.01). In the PACU and at 2, 4, and 6 hours, the sedation scores were increased in group P600 compared with the scores in group C (P < 0.001, P < 0.001, P = 0.01, P = 0.006, respectively). Patient satisfaction was higher in group P600 than in group C for all time points (P < 0.001, P < 0.001, P < 0.001, P = 0.001, P < 0.001, respectively). There were no statistically significant differences between the groups for side effects such as nausea, vomiting, and dizziness (P = 0.58). CONCLUSIONS Pregabalin at a total dose of 600 mg, administered before operation and at 12 hours postoperatively after abdominal hysterectomy, reduced morphine consumption and pain intensity and increased patient satisfaction. No significant differences in side effects were observed between the study groups.

The effects of single-dose tramadol on post-operative pain and morphine requirements after coronary artery bypass surgery.

Aim:  To investigate the effects of a single dose of tramadol administered prior to extubation on post‐operative pain and morphine consumption after coronary artery bypass surgery.

Effects of Perineural Administration of Dexmedetomidine in Combination with Levobupivacaine in a Rat Sciatic Nerve Block

Objective The aim of this study was to assess if perineural administration of dexmedetomidine combined with levobupivacaine increases the duration of the sensory and motor blockade of a sciatic peripheral nerve block in rats. Methods Forty male Sprague–Dawley rats were randomly divided into 5 experimental groups: Group 1, sham; Group 2, perineural levobupivacaine (0.2 mL of a 0.5% solution) and subcutaneous saline; Group 3, perineural levobupivacaine (0.2 mL of a 0.5% solution) plus dexmedetomidine (20 µg/kg dexmedetomidine) and subcutaneous saline; Group 4, perineural saline and subcutaneous dexmedetomidine; and Group 5, perineural saline and subcutaneous saline. Pain reflexes in response to a thermal stimulus were measured at 0 and 240 minutes after drug administration by using a hot-plate and tail-flick tests. Neurobehavioral status, including sensory and motor functions, was assessed by an investigator who was blinded to the experimental groups every 30 minutes until normal functioning resumed. Results The sensory and motor blockades of the rats did not increase in the treatment with dexmedetomidine plus levobupivacaine when compared with the treatment with levobupivacaine alone at all the time points (P > 0.05). Compared with rats in Group 2, those in Group 3 showed significantly higher latency times at 30 and 60 minutes in the hot plate test (P < 0.01). At 30 and 60 minutes, the latency times of the rats in Group 3 were longer than those in Group 2 in the tail-flick test (P < 0.01). Furthermore, the durations of the complete sensory and motor blockade were similar when treatment with levobupivacaine plus dexmedetomidine was compared with treatment with levobupivacaine alone. Conclusions A 20µg/kg dose of dexmedetomidine added to levobupivacaine did not increase the duration of the sensory and motor blockades in rats. However, treatment with dexmedetomidine plus levobupivacaine increased the quality of analgesia in rats.

Effects of Oral β- Glucan on Liver Ischemia/Reperfusion Injury in Rats

AIM Ischemia/reperfusion (IR) injury (IRI) in liver transplant patients may negatively affect graft function. Although β-glucan protects kidneys against IRI, its effect on the liver is unknown. This study sought to investigate β-glucan effects on oxidative damage to the liver after IRI in rats. MATERIALS AND METHODS Thirty-two rats were randomly divided into 4 experimental groups n = 8 in each group: sham, IR, β-glucan and IR + β-glucan. β-Glucan (50 mg.kg(-1) . day(-1)) was orally administered for 10 days to rats in the β-glucan and IR + β-glucan groups. The rats in the IR and IR + β-glucan groups were subjected to ischemia and reperfusion (IR) for 60 minutes each. All rats were killed on day 11 to evaluate histological changes as well as tissue levels of oxidants and antioxidants. RESULTS Malondialdehyde (MDA) levels were significantly higher in the IR than the sham group (P = .001). MDA level was significantly higher in the IR group than in the IR + β-glucan group (P = .001). The levels of tissue antioxidant markers (superoxide dismutase [SOD], glutathione-peroxidase [GPx], and catalase [CAT]) were significantly lower in the IR group than in the sham group (P < .05). SOD and GPx levels did not differ significantly between the IR and IR + β-glucan groups. CAT activity was significantly higher in the IR than the IR + β-glucan group (P = .001). Histological tissue damage was reduced in the IR + β-glucan than the IR group. CONCLUSION Liver IRI is an inevitable problem during liver surgery. Our results suggested that β-glucan pretreatment suppressed oxidative stress and increased antioxidant levels in an rat model of liver IRI.

The effects of intra-operative low-dose dexmedetomidine infusion on postoperative pain in patients undergoing septorhinoplasty

Abstract Study objective: To determine the effects of intra-operative low-dose dexmedetomidine infusion on postoperative morphine consumption, pain, sedation and patient satisfaction in patients undergoing septorhinoplasty. Method: Fifty adult patients were randomised to receive either dexmedetomidine (a loading dose of 1 μg kg−1 for the first ten minutes and a maintenance dose of 0.2 μg kg−1 h−1 afterwards, Group D) or 0.9% saline in the same manner (Group C) after induction of anaesthesia. At the end of the operation, the infusions were discontinued. After extubation, patient controlled analgesia was started intravenously. Results: Patients in Group D consumed 47% less morphine than patients in Group C during the first 24 h and had a lower cumulative morphine consumption at all times after starting patient controlled analgesia (7.08 mg vs. 8.56 mg at 2 h (p < 0.05), 10.84 mg vs. 14.0 mg at 4 h (p < 0.05), 13.56 mg vs. 18.28 mg at 6 h (p < 0.05) and 17.96 mg vs. 33.72 mg at 24 h (p < 0.05), respectively ...