Yasemin Güneş

Comparison of nerve conduction blocks by an opioid and a local anesthetic

The experiments were done on frog sciatic nerves, using a sucrose-gap recording technique. The aim of our study was to investigate and to compare the tonic and phasic conduction blocking potency of tramadol and lidocaine on whole nerve and their interactions with Ca(2+). The concentration of a tramadol solution producing the same amount of tonic and phasic conduction blocks was three and six times higher than that needed for lidocaine, respectively. Increasing the Ca(2+) concentration in the test solution enhanced the conduction blocking potency of tramadol, but decreased that of lidocaine. It is concluded that tramadol blocks nerve conduction like a local anesthetic but with a weaker effect than that of lidocaine. Interactions of Ca(2+) and these drugs suggested that these drugs might have either different binding sites or different action mechanisms.

Comparative study of the antiemetic efficacy of ondansetron, propofol and midazolam in the early postoperative period

Background and objective: To compare the antiemetic efficacy of ondansetron with two different hypnotic drugs (propofol 15 mg, midazolam 1 and 2 mg) for the treatment of established postoperative nausea and vomiting (PONV). Methods: Four-hundred-and-fifty-three patients scheduled for elective gynaecological or abdominal surgery were enrolled. One-hundred-and-twenty patients (26%) experienced postoperative emesis, and when nausea scores reached 2 or greater on a five-point scale, they were randomized to receive intravenously: propofol 15 mg (1.5 mL) in Group P, midazolam 1 mg in Group M1, midazolam 2 mg in Group M2 and ondansetron 4 mg in Group O. Results: Four patients (13.3%) in Group P, 13 patients (43.3%) in Group M1, five patients (16.6%) in Group M2 and one patient (3.3%) in Group O required a second dose of the study drug. After administration of the study drugs, nausea scores were significantly lower in all groups than before these drugs were given. No patient had a sedation score over 3 (the patients remained awake and/or responded to verbal contact). The sedative effects of midazolam and propofol lasted for a much shorter time than the antiemetic effects of these drugs. Conclusions: Propofol and midazolam used in subhypnotic doses were as effective as ondansetron in treating PONV in patients undergoing abdominal or gynaecological surgery without untoward sedative or cardiovascular effects.

Comparison of morphine and tramadol by patient-controlled analgesia for postoperative analgesia after tonsillectomy in children

Background : Tramadol is an alternative to other opioids for postoperative pain management. This prospective, randomized, double‐blind study was designed to compare the analgesic efficacy of patient‐controlled tramadol with patient‐controlled morphine for postoperative pain after tonsillectomy in children.

Comparison of caudal vs intravenous tramadol administered either preoperatively or postoperatively for pain relief in boys

Background : In this study we compared caudal with intravenous (i.v.) tramadol given pre‐ or postoperatively for pain relief in boys having hypospadias repair.

Comparison of caudal ropivacaine, ropivacaine plus ketamine and ropivacaine plus tramadol administration for postoperative analgesia in children

Background : The aim of this study was to compare the effect of single‐dose caudal ropivacaine, ropivacaine plus ketamine and ropivacaine plus tramadol in children for postoperative pain management.

Differential effects of lidocaine and tramadol on modified nerve impulse by 4-aminopyridine in rats

We have used the sucrose gap method to measure the effects of drugs on the electrophysiological properties of rat sciatic nerves. The results showed that 4-aminopyridine produced a slight conduction block, prolonged the duration of action potential, enhanced the hyperpolarizing afterpotential, and elicited a hump that followed the action potential. In the presence of 4-aminopyridine, the impulse-blocking activity of lidocaine and tramadol was enhanced. Both lidocaine and tramadol effectively depressed the delayed depolarization generated by 4-aminopyridine. While tramadol decreased the activity-evoked hyperpolarizing afterpotentials, lidocaine completely removed them. These findings indicate that lidocaine may be more effective in blocking the Na+ channels than tramadol. Tramadol may be more effective on the delayed rectifier K+ channels than lidocaine.

The comparison of caudal ketamine, alfentanil and ketamine plus alfentanil administration for postoperative analgesia in children

Background: Our aim was to compare the effect of single dose caudal ketamine, alfentanil or a mixture of both drugs in the treatment of pain after hypospadias repair surgery in children.

Congenital intracranial immature teratoma of the lateral ventricle: a case report and review of the literature.

Abstract Objective: Congenital intracranial tumors are very rare and only account for 0.5–1.5% of all childhood brain tumors. The most common type of these tumors present at birth is teratomas, which represent 0.5% of all intracranial tumors. Most teratomas are midline tumors located predominantly in the sellar and pineal regions. In this study, we report a neonatal intracranial immature teratoma at the lateral ventricle because of its rare location. Case Report: A 3-day-old female neonate presented with a history of irritability, vomiting, and recurrent generalized clonic seizures since birth. A head computed tomographic scan and magnetic resonance imaging disclosed a large tumor filling the right lateral ventricle and extending into the ipsilateral posterior fossa. With right parieto-occipital craniotomy, large grayish-white lobulated vascular mass was encountered and total removal of tumor was performed. Histological examination revealed the diagnosis of immature teratoma. Conclusion: The prognosis of congenital intracranial immature teratoma is usually poor because the lesions are extensive when they are identified. Prenatal ultrasonography is necessary for the prenatal diagnosis. Fetal magnetic resonance imaging should be made for the evaluation of intracranial tumor. If the tumor is detected before the 24 week of gestation, termination of the pregnancy should be considered.

Comparison of effects of ketamine, ketamine-dexmedetomidine and ketamine-midazolam on dressing changes of burn patients

Objective: The aim of this randomized, controlled study was to compare the sedoanalgesic effects of ketamine-dexmedetomidine and ketamine-midazolam on dressing changes of burn patients. Materials and Methods: Following Ethics Committee approval and informed patient consent, 90 ASA physical statuses I and II adult burn patients were included in the study. Patients were randomly divided into three groups. Ten minutes before dressing change, the dexmedetomidine group (group KD) (n = 30) received a continuous infusion of dexmedetomidine at a rate of 1 μg kg-1, the midazolam group (group KM) (n = 30) received a continuous infusion of midazolam at a rate of 0.05 mg kg-1 and the saline group (group KS) (n = 30) received a continuous infusion of saline intravenously. One minute before dressing change, each patient was administered 1 mg kg-1 ketamine intravenously. Hemodynamic variables, pain and sedation scores, the number of patients requiring additional ketamine, time to dressing change and recovery time were recorded. Results: Systolic blood pressure (SBP) values were significantly lower at, before and after ketamine administration; and 5, 10 and 15 minutes after the procedure in group KD in comparison with the other groups (P <0.05). There was no significant difference in pain scores among the groups during the study period. Sedation scores were significantly higher in group KD than in groups KM and KS at the end of the first hour (P <0.05). Time to dressing change and recovery time were similar in all the groups Conclusion: In burn patients undergoing dressing changes, although both combinations ketamine-dexmedetomidine and ketamine-midazolam offered an effective sedoanalgesia without causing any significant side effect, the former resulted in higher sedation and lower hemodynamic discrepancy.

A double-blind comparison of intrathecal S(+) ketamine and fentanyl combined with bupivacaine 0.5% for Caesarean delivery

Background: In this prospective, randomized, double‐blind, controlled study, we investigated the sensory, motor and analgesic block characteristics of S(+) ketamine, fentanyl and saline given intrathecally (IT) in addition to 0.5% plain bupivacaine (10 mg) for spinal analgesia. Methods: Ninety ASA I or II adult patients undergoing Caesarean section were randomly allocated to receive 1.0 mL of 0.9% saline in Group S (n = 30), 0.05 mg kg−1 of S(+) ketamine (1.0 mL) in Group K (n =30) or 25 μg (1.0 mL) of fentanyl in Group F (n =30) following 10 mg of plain bupivacaine 0.5% IT. We recorded onset and duration of sensory and motor block, time to reach the maximal dermatomal level of sensory block and duration of spinal analgesia. Results: The onset time of sensory and motor block was significantly shorter in Groups K and F than in Group S (P < 0.014). Their duration was significantly longer in Group F than in Groups K and S (P < 0.009). The time to reach the maximal dermatomal level of sensory block was significantly shorter in Groups K and F than in Group S (P < 0.001). The duration of spinal analgesia was significantly longer in Group F than in Groups K and S (P < 0.001). Conclusion: In patients undergoing Caesarean section with spinal analgesia, the addition of S(+) ketamine (0.05 mg kg−1) IT to 10 mg of spinal plain bupivacaine (0.5%) led to rapid onset of both sensory and motor blockade and enhanced the segmental spread of spinal block without prolonging the duration of spinal analgesia, whereas fentanyl provided prolonged analgesia.