Emine Arzu Kose

The efficacy of ketamine for the treatment of postoperative shivering.

BACKGROUND:There are few reports on the utility of ketamine for the prevention of postoperative shivering. We thus established the efficacy of two doses of ketamine compared with meperidine for the treatment of postoperative shivering. METHODS:This is a prospective, randomized double-blind study involving 90 ASA I–II patients after general anesthesia. Patients with shivering grade 3–4 were allocated to receive either meperidine 25 mg, ketamine 0.5 mg/kg, or ketamine 0.75 mg/kg IV. Shivering and side effects were monitored at set time intervals. RESULTS:Shivering grades for the first 4 min after treatment were lower in the ketamine groups; however, nystagmus and feeling like “walking in space” was experienced with both doses of ketamine. CONCLUSION:Ketamine 0.5–0.75 mg/kg is more rapid than meperidine (25 mg) for the reduction of postoperative shivering, but the side effect profile may limit its usefulness.

Prophylactic ketamine to prevent shivering in parturients undergoing Cesarean delivery during spinal anesthesia.

STUDY OBJECTIVE To compare the efficacy and safety of ketamine 0.25 mg/kg with ketamine 0.5 mg/kg to prevent shivering in patients undergoing Cesarean delivery. DESIGN Prospective, randomized, double-blinded, placebo-controlled study. SETTING Operating rooms and postoperative recovery rooms. PATIENTS 120 ASA physical status 1 and 2 pregnant women scheduled for Cesarean delivery during spinal anesthesia. MEASUREMENTS Patient characteristics, anesthetic and surgical details, Apgar scores at 1 and 5 minutes, and side effects of the study drugs were recorded. Heart rate, mean arterial pressure, oxygen saturation via pulse oximetry, tympanic temperature, severity of shivering, and degree of sedation were recorded before intrathecal injection and thereafter every 5 minutes. Patients were randomized to three groups: saline (Group C, n=30), intravenous (IV) ketamine 0.25 mg/kg (Group K-0.25, n=30), or IV ketamine 0.5 mg/kg (Group K-0.5, n=30). Grade 3 or 4 shivering was treated with IV meperidine 25 mg and the prophylaxis was regarded as ineffective. MAIN RESULTS The number of shivering patients was significantly less in Group K-0.25 and in Group K-0.5 than in Group C (P = 0.001, P = 0.001, respectively). The tympanic temperature values of Group C were lower at all times of the study than in either ketamine group. Median sedation scores of Group K-0.5 were significantly higher than in Group K-0.25 or Group C at 10, 20, 30, and 40 minutes after spinal anesthesia. CONCLUSIONS Prophylactic IV ketamine 0.25 mg/kg was as effective as IV ketamine 0.5 mg/kg in preventing shivering in patients undergoing Cesarean section during spinal anesthesia.

Evaluation of the neurotoxicity of DMSO infused into the carotid artery of rat

INTRODUCTION Despite the explanations put forth in many studies regarding histopathological evidence of the inflammatory stage related with the infusion of dimethyl sulfoxide (DMSO) in the vessel wall and its lumen, there has been no research to evaluate its neural toxicity when it is infused via the intracarotid route. This study was designed to evaluate the possible neurotoxic effects of DMSO on the closer and distant brain tissue and carotid artery when it was slowly infused into the internal carotid arteries of the rats. METHODS The right common carotid artery bifurcation was exposed through a midline neck incision, and then except those of the control group animals (n=5), the experimental material (normal saline, n=5 or anhydrous DMSO, n=10) was infused into the internal carotid artery of the Wistar albino rats. After the experimental materials were administered intra-arterially, brain tissues were harvested for histopathological and biochemical studies at 72 h for investigation of the acute stage changes and on 10th day for investigation of the chronic stage changes. Internal carotid arteries of both sides were also removed for histopathological evaluation. During sacrification of the rats, whole body blood of them are collected for biochemical evaluation. RESULTS There was no statistically significant difference between the groups regarding comparison of the mean values of the hippocampal neuronal cell counts and the carotid artery diameters in both acute and chronic stages. Also, mean values of the lipid peroxidation levels of harvested brain tissues and serums of the collected bloods were similar in control, saline and DMSO groups. CONCLUSION This experimental study suggested that DMSO has no toxic effect on the neural and arterial tissues of rats when it is slowly infused into the carotid artery.

Neuroprotective effects of racemic ketamine and (S)-ketamine on spinal cord injury in rat

BACKGROUND The aim of this study was to investigate and to compare the potential neuroprotective effects of racemic ketamine, (S)-ketamine and methylprednisolone after an experimental spinal cord injury model in rats. METHODS Fifty-nine Wistar albino rats were divided into three main groups as acute stage (A), subacute stage (SA) and sham groups and then acute and subacute stage groups were divided into four groups regarding the used drug as control (CONT), racemic ketamine (RK), (S)-ketamine (SK) and methylprednisolone (MP) groups. A dorsal laminectomy was performed; and spinal cord injury was induced by using a temporary aneurysm clip. Four hours later from the clip compression, except those of the sham and control groups, the drugs (60 mg/kg racemic ketamine, 60 mg/kg (S)-ketamine or 30 mg/kg methylprednisolone) were administered intraperitoneally. At 72th h and 7th days of the study, the spinal cords of rats were removed from T8 level to the conus medullaris level. The specimens were and evaluated histopathologically, tissue lipid peroxidation (LPO) and myeloperoxidation (MPO) levels were measured and biochemically. RESULTS The histopathological results were similar both in the acute and in the subacute stage groups. There was a statistically significant difference among all groups regarding the tissue LPO levels (p<0.001). There was a statistically significant difference between the CONT-A group and the MP-A, RK-A and SK-A groups (p=0.004, p<0.001 and p=0.007, respectively) in acute stage and between the CONT-SA group and SK-SA group (p=0.002) in subacute stage. There was a statistically significant difference among all groups regarding the tissue MPO levels (p=0.001). The median MPO levels were similar among acute stage groups (p=0.057), but there was a statistical difference among subacute stage groups (p=0.046). CONCLUSION (S)-ketamine is more effective than methylprednisolone and racemic ketamine to reduce the LPO levels in subacute stage of spinal cord injury in rats. And, it is as effective as methylprednisolone in preventing secondary spinal cord injury histopathologically.

Effects of low-dose methotrexate in spinal cord injury in rats.

BACKGROUND This study was designed to evaluate the possible protective effects of low-dose methotrexate in the spinal cord injury (SCI) in rats. METHODS Thirty-seven Wistar albino rats were used in the present study. Except for the animals of the Sham group, all animals were divided into two main groups, which were used in acute and subacute stage investigations. Then, thoracal laminectomy was performed, and except for the Sham group, SCI was induced using a temporary aneurysm clip. After clip compression, the experimental material (methotrexate or methylprednisolone) was administered intraperitoneally, except in the Sham and Control groups. Then, the spinal cords were removed to evaluate the SCI histopathologically and biochemically at the scheduled date. RESULTS Neither experimental material was shown to reduce the histopathological grade in either stage of SCI. Low-dose methotrexate was shown to decrease lipid peroxidation levels only in the subacute stage of SCI. However, methylprednisolone and low-dose methotrexate could not decrease or block myeloperoxidase enzyme activation in either stage of SCI. CONCLUSION Low-dose methotrexate was effective in reducing the lipid peroxidation levels in the subacute stage of SCI, although histopathological evaluation results and myeloperoxidase levels of all groups did not support this finding at either stage.Departments of 1Neurosurgery, 2Anaestesiology and Reanimation, Kirikkale University Faculty of Medicine, Kirikkale; 3Department of Pathology, Baskent University Faculty of Medicine, Ankara; 4Department of Biochemistry, Hacettepe University Faculty of Medicine, Ankara, Turkey. Kirikkale Universitesi Tip Fakultesi, 1Norosirurji Anabilim Dali, 2Anesteziyoloji ve Reanimasyon Anabilim Dali, Kirikkale; 3Baskent Universitesi Tip Fakultesi, Patoloji Anabilim Dali, Ankara; 4Hacettepe Universitesi Tip Fakultesi, Biyokimya Anabilim Dali, Ankara.

Comparison of Effects of Dexmedetomidine-ketamine and Dexmedetomidine-midazolam Combinations in Transurethral Procedures

OBJECTIVE To compare the effects of dexmedetomidine-ketamine and dexmedetomidine-midazolam combinations on the recovery time, hemodynamic and respiratory variables, and side effects in patients undergoing transurethral procedures. METHODS Sixty patients scheduled for elective outpatient transurethral procedure were randomized into 2 groups. In the group K, a ketamine-dexmedetomidine combination was administered, and in the group M, midazolam-dexmedetomidine was administered, to provide sedation/analgesia. Pain and sedation levels were assessed using visual analog score (VAS) and Ramsey Sedation Scale, respectively. The recovery time was assessed with the scale of Aldrete. Time was measured and recorded to the moment at which patient responses brought the Aldrete score to 10 points. Time to eye opening and length of stay in the recovery room were recorded. RESULTS Group M showed significantly lower mean arterial pressure (MAP) values at 5 and 10 minutes during the procedure when compared with group K (P = .02 and P = .01, respectively). Visual analogue scale scores were greater in group M than in group K at 5 and 10 minutes for the transurethral procedure (P = .039 and P = .028, respectively). Sedation scores were similar between groups during the procedure. Time to eye opening and length of recovery room stay were shorter (P < .001 and P < .001, respectively), and Aldrete scores were greater in group K than group M. CONCLUSION Both combinations provided satisfactory sedation levels, but the dexmedetomidine-ketamine combination provided better analgesia and hemodynamic stability, with less nausea and vomiting and shorter recovery time, than the dexmedetomidine-midazolam combination.

Effects of intracisternal and intravenous dexmedetomidine on ischemia-induced brain injury in rat: a comparative study.

AIM To compare the effect of dexmedetomidine administered by intracisternal route with by intravenous route on brain tissue of rat after incomplete cerebral ischemia. MATERIAL AND METHODS Cerebral ischemia was produced by the combination of right common carotid artery occlusion and hemorrhagic hypotension during 30 minutes. Thirty minutes before the ischemia, 0.1 ml 0.9% NaCl (Group SIC, n=6) or 9 μg/kg dexmedetomidine (Group DIC, n=6) was administered into the cisterna magna. For the intravenous groups, 9 μg/kg dexmedetomidine (Group DIV, n=6) or 0.9% NaCl (Group CONTROL, n=6) 5 ml/kg/h was given in 2 hours. After 24 hours, the lipid peroxidation levels were measured in the brain tissue and plasma. Hippocampal formations were used for histopathological examination. RESULTS Intravenous dexmedetomidine produced a decrease in baseline mean arterial blood pressure and plasma glucose concentrations. There was a significant difference between the DIV group and DIC, SIC, CONTROL groups regarding the brain lipid peroxidation levels (p < 0.001, p < 0.001, p=0.001, respectively), and regarding the picnotic neuronal cell count (p < 0.001, p=0.01, p=0.009, respectively). Mean plasma lipid peroxidation levels of the DIV group was different from the DIC group (p=0.003). CONCLUSION Systemically administered dexmedetomidine had neuroprotective effect in ischemia-induced neuronal damage, but centrally administered dexmedetomidine did not.

Evaluation of the neurotoxicity of the polyethylene glycol hydrogel dural sealant.

AIM Although polyethylene glycol (PEG) is a neutral, biocompatible hydrophilic polymer recognized for its lack of interaction with biological barrier, its neurotoxicity has not been clearly identified in neurosurgery. This study is constructed to evaluate the possible neurotoxicity of a PEG hydrogel dural sealant. MATERIAL AND METHODS After a burrhole was opened in the left parietal bone of the twenty five Wistar albino rats, the dura mater and cerebral cortex were incised and the experimental material (activated polyethylene glycol and polyethylene imine) was sprayed into the burrhole. Then brain tissues were harvested for histopathological and biochemical studies at 72 hours to investigate the acute stage changes and on 15th day to evaluate the chronic stage changes. RESULTS There were statistically significant differences among the groups regarding the comparison of the values of the PMNL cell infiltration grades, gliosis and congestion in both acute and chronic stages. However, the values of the MNL cell infiltration grades, edema and fibrin formation, lipid peroxidation levels of harvested brain tissues were similar in all groups. CONCLUSION Although this study did not present the detailed histopathological and biochemical evaluation results, it indicated that the application of the PEG-based hydrogel sealant was not associated with neurotoxicity, delayed healing, or degenerative changes.

Anesthesia for a child with Walker-Warburg syndrome.

BACKGROUND AND OBJECTIVES Walker-Warburg Syndrome is a rare, autosomal recessive congenital muscular dystrophy manifested by central nervous system, eye malformations and possible multisystem involvement. The diagnosis is established by the presence of four criteria: congenital muscular dystrophy, type II lissencephaly, cerebellar malformation, and retinal malformation. Most of the syndromic children die in the first three years of life because of respiratory failure, pneumonia, seizures, hyperthermia and ventricular fibrillation. CASE REPORT The anesthetic management of a two-months-old male child listed for elective ventriculo-peritoneal shunt operation was discussed. CONCLUSIONS A careful anesthetic management is necessary due to the multisystem involvement. We reported anesthetic management of a two-months-old male child with Walker-Warburg Syndrome who was listed for elective ventriculo-peritoneal shunt operation.

Efficacy of Prophylactic Ketamine in Preventing Postoperative Shivering

BACKGROUND Treatment with ketamine and pethidine is effective in postoperative shivering. The aim of this study was to compare the efficacy of low-dose prophylactic ketamine with that of pethidine or placebo in preventing postoperative shivering. METHODS A prospective randomized double-blind study involved 90 ASA I and II patients undergoing general anaesthesia. Patients were randomly allocated to receive normal saline (Group S, n=30), pethidine 20 mg (Group P, n=30) or ketamine 0.5 mg kg(-1) (Group K, n=30) intravenously 20 min before completion of surgery. The anaesthesia was induced with propofol 2 mg kg(-1), fentanyl 1 microg kg(-1) and vecuronium 0.1 mg kg(-1). It was maintained with sevoflurane 2-4% and nitrous oxide 60% in oxygen. Tympanic temperature was measured immediately after induction of anaesthesia, 30 min after induction and before administration of the study drug. An investigator, blinded to the treatment group, graded postoperative shivering using a four-point scale and postoperative pain using a visual analogue scale (VAS) ranging between 0 and 10. RESULTS The three groups did not differ significantly regarding patient characteristics. The number of patients shivering on arrival in the recovery room, and at 10 and 20 min after operation were significantly less in Groups P and K than in Group S. The time to first analgesic requirement in Group S was shorter than in either Group K or Group P (P<0.005). There was no difference between the three groups regarding VAS pain scores. CONCLUSION Prophylactic low-dose ketamine was found to be effective in preventing postoperative shivering.