Dilek Ozdamar

The learning curve in endoscopic pituitary surgery and our experience

Experience is the important point in reduction of the complications and in the effectiveness of the surgical procedure in pituitary surgery. Endoscopic pituitary surgery differs from microscopic surgery, since it requires a steep learning curve for endoscopic skills. In this article, we evaluate our learning curve in two groups, as early and late experience. Purely endoscopic transsphenoidal operations were performed on 78 patients, which were retrospectively reviewed and grouped as early and late experience groups. We used the purely endoscopic endonasal approach to the sella that was performed via an anterior sphenoidotomy, without the use of a transsphenoidal retractor. All patients with adenomas were evaluated considering operation time, endocrinology, ophthalmology, total removal and, especially, modifications of standard technique. On the basis of the experience gained with the use of the endoscope in transphenoidal surgery over the years, modifications can be performed on the different phases of the endoscopic approach. Reviewing our cases in two groups of period due to our experience showed that the effectiveness of endoscopic surgery increases and operation time decreases. In our study, we identified a learning curve in endoscopic pituitary surgery.

A new supraglottic airway device: LMA‐Supreme™, comparison with LMA‐Proseal™

Background and objective: The LMA‐Supreme™ (S‐LMA™) is a new supraglottic airway device that presents combined features of flexibility, curved structure and single use and a different cuff structure. The purpose of this study was to compare the oropharyngeal leak pressures (OLP) of LMA‐Proseal™ (P‐LMA™) and S‐LMA™.

Spinal anesthesia for arthroscopic knee surgery.

Background and objective:  The purpose of the study was to compare the effects of adding 50 µg of morphine, 25 µg of fentanyl or saline to 6 mg of hyperbaric bupivacaine on postoperative analgesia and time to urination in patients undergoing arthroscopic knee surgery under spinal anesthesia.

Comparison of ProSeal LMA with Supreme LMA in paediatric patients.

Supreme laryngeal mask airway (S‐LMA) has been improved in recent years, but comparative studies with a sizeable number of paediatric patients are limited in number. In this study, oropharyngeal leak pressures (OLPs) were compared between S‐LMA and ProSeal laryngeal mask airway (P‐LMA) in paediatric patients.

Levobupivacaine–tramadol combination for caudal block in children: a randomized, double‐blinded, prospective study1

Background:  The aim of this prospective study was to compare the postoperative analgesic efficacy and duration of analgesia after caudal levobupivacaine 0.125% or caudal tramadol 1.5 mg·kg−1 and mixture of both in children undergoing day‐case surgery.

Lateral sagittal infraclavicular block is a clinically effective block in children

EDITOR: Infraclavicular block is gaining popularity due to ease of performance and high success rate, also in children [1]. Following a magnetic resonance imaging (MRI) study in volunteers, Klaastad and colleagues [2] suggested that infraclavicular block could be accomplished by the ‘lateral sagittal route’ with ease and low risk of complications like pneumothorax. The lateral sagittal infraclavicular block (LSIB) technique is well accepted by adult patients, and in large clinical series using single-injection technique with the aid of a nerve stimulator, the block success rate ranges between 89.7% and 91% [3,4]. Until now only a case report [5] and a letter [6] have reported successful use of LSIB in children. The primary purpose of this study was to evaluate the clinical utility of LSIB in children undergoing upper extremity surgery under general anaesthesia. After approval by Kocaeli University Ethics Committee and written informed consent from the parents, a prospective and descriptive study was performed on patients scheduled for elective or acute hand, forearm and elbow surgery. Consecutive children (age range 4–12 yr of age), ASA physical status I, having surgery between June 2005 and July 2007 were included in the study. All children included into the study were informed about the possible effects of the study including analgesia and motor block. More detailed verbal information was given and oral consent was obtained in older children. Children who could not cooperate, those who had a congenital or acquired brachial plexus defect/injury, patients with coagulopathy, allergy to any of the study drugs, with previous surgery or trauma that prevented the anatomic localization of the injection point were excluded from the study. EMLA cream (Astra Zeneca, Wedel, Germany) was applied to the non-injured hand for venous puncture. After insertion of a venous cannula, all patients received midazolam 0.05–0.1 mg kg intravenous for sedation. In the operating room, patients were monitored with electrocardiogram, non-invasive blood pressure and pulse oximetry. General anaesthesia was induced with propofol 1% and fentanyl 1 mg kg and a Proseal LMA was inserted. Anaesthesia was maintained with 1 : 1 N2O : O2, sevoflurane 1–2% and spontaneous ventilation. The lungs of all children were auscultated before and after infraclavicular block performances. A chest X-ray was planned as a security measure in case of clinical signs of pneumothorax. The puncture site was checked repeatedly to detect any swelling or haematoma formation. With the anaesthesiologist standing behind the patient’s shoulder, the arm to be blocked was adducted and the hand placed on the abdomen. The patient’s head was turned to the side opposite to that on which the block was to be performed. The puncture site was immediately adjacent to the most medial point of the coracoid process and the anterior surface of the clavicle (Fig. 1). After antiseptic preparation of the area, a 22-G, 50 mm, insulated needle (Stimuplex A, B Braun Medical) was connected to the active lead of the nerve stimulator (Stimuplex HNS 11; B Braun Medical, Melsungen, Germany) and set to deliver 1.5 mA current impulses of 0.1 ms duration at a frequency of 2 Hz. A distinct distal motor response at the level of the hand or wrist at a current output ranging between 0.3 and 0.5 mA was obtained in all patients. The needle was inserted caudally in a sagittal plane, 208 dorsally (to the horizontal plane), until muscle twitches were observed in synchrony with the stimulation. Biceps twitches were ignored and the needle was advanced deeper until one of the following finger/wrist twitches were obtained: second and third finger flexion was accepted as a median nerve response, flexion of the fourth and fifth fingers as an ulnar nerve response and finger or wrist extension as a radial nerve response. During needle insertion and redirections, continuous aspiration was performed by an assistant to detect any possible intravascular puncture. All patients received 0.5 mL kg of bupivacaine 0.25% with adrenaline 5 mg mL. All blocks were performed by the same anaesthesiologist with experience in LSIB. Analgesia and motor block durations were recorded during 24 h. In the early postoperative period in the recovery unit, patients were asked if they had pain or not. Analgesia duration was defined as the interval Correspondence to: Yavuz Gürkan, Kuruçes -me, Doruk Sitesi, C Blok D: 4, 41100, Kocaeli, Turkey. E-mail: yavuzg@superonline.com; Tel: 190 533 7106245; 190 262 3037056; Fax: 190 262 3038003

Anaesthetic considerations and perioperative features of endoscopic third ventriculostomy in infants: analysis of 57 cases.

AIM Endoscopic third ventriculostomy (ETV) is currently considered the best alternative to shunt systems in the treatment of triventricular hydrocephalus. However, there has been very few published data about the anaesthetic management and the complications of ETV procedure in infants. In this report, we detail our experience with 57 infants, who underwent ETV as an initial treatment for obstructive triventricular hydrocephalus between 2003 and 2010. MATERIAL AND METHODS Anesthesia chart-records were retrospectively investigated and perioperative data were classified according to the stages of the procedure. RESULTS In this series, mean heart rate values showed a statistically significant difference in the period concerning the balloon dilatation of ventriculostomy orifice. An episode of bradycardia occurred in 2 patients during balloon dilatation. After the deflation of the balloon, bradycardia resolved immediately without administration of any medication. Video recordings of those two patients revealed that one of them had a narrow and opaque tuber cinereum, and the other had a shallow interpeduncular cistern. CONCLUSION During ETV procedure in infants, bradycardia may be a serious complication especially when performing balloon dilatation of the ventriculostomy orifice. We believe that close communication between the surgeon and the anaesthetist is extremely essential in this stage of the procedure.

Effect of Preoperative Epidural Morphine Administration on Desflurane Requirements During Gynecologic Surgery

Background and Objectives: The goal of this study is to examine the influence of epidural morphine on the end-tidal desflurane concentration titrated to maintain the bispectal index (BIS) values between 40 and 60 during gynecologic surgery. Methods: Forty patients undergoing transabdominal hysterectomy under general anesthesia were randomly and prospectively assigned to 1 of 2 study groups: group saline (group S) and group morphine (group M). After placing an epidural catheter at L3-4 or L4-5, patients received either 10 mL of saline or 4 mg of morphine in 10 mL of saline approximately 60 minutes before anesthesia induction. Anesthesia maintenance was provided with desflurane and nitrous oxide in oxygen with a ratio of 2:1 by an anesthesiologist blinded to the group. Measurements included BIS value, end tidal desflurane concentration, heart rate, and blood pressure before surgery and every 10 minutes during surgery. Results: Although there was a tendency to slightly lower end-tidal desflurane concentrations in the morphine group, this difference did not reach statistical significance at any time. In the morphine group, the heart rate was lower than in the saline group at 20, 30, 40, and 50 minutes of surgery (P < .05). BIS values were similar throughout surgery. Conclusions: Preoperative administration of epidural morphine does not reduce desflurane requirements in patients undergoing gynecologic surgery.

Comparison of forced-air warming systems in prevention of intraoperative hypothermia

In this study, we aimed to compare the effects of forced-air warming upper body blankets and forced-air warming underbody blankets on intraoperative hypothermia in patients who were planned to undergo open abdominal surgical operations in which extensive heat loss occurs. This prospective and randomized study included 92 patients who would undergo lower abdominal surgery under general anesthesia. Patients were randomized by closed envelope method and divided into two groups. Group I (n:46) included the patients who would receive warming with forced-air warming upper body blanket, and Group II (n:46) consisted of the patients who received warming with forced-air warming underbody blanket. Central body temperature was recorded by measuring with a temperature probe placed in distal esophagus. Demographic data, amount of fentanyl, crystalloid and blood products used, duration of operation, type of operation, hemodynamic parameters, shivering and thermal damage information were recorded. There was not any statistically significant difference among the patients in terms of demographic data, amount of fentanyl, crystalloid and blood products used, duration and type of operation and hemodynamic parameters. No difference was found between the groups in terms of body temperatures (Group I:36.1 °C, Group II:36.3 °C, respectively) (P > 0.05). Forced air warming underbody blanket can be as effective as forced-air warming upper body blankets in preventing intraoperative hypothermia. They can be alternative in cases where use of forced-air warming upper body blankets is not feasible.

Evaluation of the neurotoxicity of intrathecal dexmedetomidine on rat spinal cord (electromicroscopic observations)

Background: Spinal administration of dexmedetomidine has been proposed as an adjuvant in spinal anesthesia. However, there is limited information about its possible neurotoxic effect after its neuraxial administration. Potential spinal neurotoxicity should be investigated in animals before administering drugs through the spinal cord. Our aim was to investigate the neurotoxic effects of intrathecal dexmedetomidine in rats. Methods: Two groups were performed: the dexmedetomidine (D) group (n = 10) received 10 μg (0.5 ml), whereas the control (C) group (n = 10) received 0.9% (0.5 ml) sodium chloride through indwelling intrathecal catheter. Seven days after the injection, the medulla spinalis was extracted. Samples were withdrawn from both groups for histologic, electron microscopic examination. The histologic examination was performed separately on each of the four sites. The findings were categorized as follows: 0 - normal neuron; 1 - intermediate neuron damage; and 2 - neurotoxicity. Results: Intrathecal administration of dexmedetomidine sensorial block was seen in the dexmedetomidine group and significant differences in the dexmedetomidine group than control group in 15th and 30th min (P < 0.05). Histological examination did not show evidence suggestive of neuronal body or axonal lesion, gliosis, or myelin sheath damage in any group. In all animals, there were observed changes compatible with unspecific inflammation at the tip of the needle location. On the four-area scoring histologic examination, the scores of both groups were 0–1, and no statistical difference was observed between the groups. Conclusions: A single dose of intrathecal dexmedetomidine did not produce histologic evidence of neurotoxicity.