Preserving the cerebellar hemispheric tentorial bridging veins through a novel tentorial cut technique for supracerebellar approaches.

OBJECTIVE: The objective of this study was to describe the distribution pattern of cerebellar hemispheric tentorial bridging (CHTB) veins on the tentorial surface in a case series of perimedian or paramedian supracerebellar approaches and to describe a novel technique to preserve these veins. METHODS: A series of 141 patients with various pathological processes in different locations was operated on via perimedian or paramedian supracerebellar approaches by the senior author from July 2006 through October 2022 and was retrospectively evaluated. During surgery, the number and locations of all CHTB veins were recorded to establish a distribution map on the tentorial surface, divided into nine zones. Patients were classified into four groups according to the surgical technique used to manage CHTB veins: 1) group 1 consisted of CHTB veins preserved without intervention during surgery or no CHTB veins found in the surgical route; 2) group 2 included CHTB veins coagulated during surgery; 3) group 3 included CHTB veins preserved with arachnoid and/or tentorial dissection from the cerebellar or tentorial surface, respectively; and 4) group 4 comprised CHTB veins preserved using a novel tentorial cut technique. RESULTS: Overall, 141 patients were included in the study. Of these 141 patients, 38 were in group 1 (27%), 32 in group 2 (22.7%), 47 in group 3 (33.3%), and 24 in group 4 (17%). The total number of CHTB veins encountered was 207 during surgeries on one side. According to the distribution zones of the tentorium, zone 5 had the highest density of CHTB veins, while zone 7 had the lowest. Of the patients in group 4, 6 underwent the perimedian supracerebellar approach and 18 had the paramedian supracerebellar approach. There were 39 CHTB veins on the surface of the 24 cerebellar hemispheres in group 4. The tentorial cut technique was performed for 27 of 39 CHTB veins. Twelve veins were not addressed because they did not present any obstacles during approaches. During surgery, no complications were observed due to the tentorial cut technique. CONCLUSIONS: Because there is no way to determine whether a CHTB vein can be sacrificed without complications, it is important to protect these veins in supracerebellar approaches. This new tentorial cut technique in perimedian or paramedian supracerebellar approaches makes it possible to preserve CHTB veins encountered during supracerebellar surgeries.

Microsurgical management of midbrain gliomas: surgical results and long-term outcome in a large, single-surgeon, consecutive series.

OBJECTIVE: The authors report on a large, consecutive, single-surgeon series of patients undergoing microsurgical removal of midbrain gliomas. Emphasis is put on surgical indications, technique, and results as well as long-term oncological follow-up. METHODS: A retrospective analysis was performed of prospectively collected data from a consecutive series of patients undergoing microneurosurgery for midbrain gliomas from March 2006 through June 2022 at the authors' institution. According to the growth pattern and location of the lesion in the midbrain (tegmentum, central mesencephalic structures, and tectum), one of the following approaches was chosen: transsylvian (TS), extreme anterior interhemispheric transcallosal (eAIT), posterior interhemispheric transtentorial subsplenial (PITS), paramedian supracerebellar transtentorial (PST), perimedian supracerebellar (PeS), perimedian contralateral supracerebellar (PeCS), and transuvulotonsillar fissure (TUTF). Clinical and radiological data were gathered according to a standard protocol and reported according to common descriptive statistics. The main outcomes were rate of gross-total resection; extent of resection; occurrence of any complications; variation in Karnofsky Performance Status score at discharge, 3 months, and last follow-up; progression-free survival (PFS); and overall survival (OS). RESULTS: Fifty-four patients (28 of them pediatric) met the inclusion criteria (6 with high-grade and 48 with low-grade gliomas [LGGs]). Twenty-two tumors were in the tegmentum, 7 in the central mesencephalic structures, and 25 in the tectum. In no instance did the glioma originate in the cerebral peduncle. TS was performed in 2 patients, eAIT in 6, PITS in 23, PST in 16, PeS in 4, PeCS in 1, and TUTF in 2 patients. Gross-total resection was achieved in 39 patients (72%). The average extent of resection was 98.0% (median 100%, range 82%-100%). There were no deaths due to surgery. Nine patients experienced transient and 2 patients experienced permanent new neurological deficits. At a mean follow-up of 72 months (median 62, range 3-193 months), 49 of the 54 patients were still alive. All patients with LGGs (48/54) were alive with no decrease in their KPS score, whereas 42 showed improvement compared with their preoperative status. CONCLUSIONS: Microneurosurgical removal of midbrain gliomas is feasible with good surgical results and long-term clinical outcomes, particularly in patients with LGGs. As such, microneurosurgery should be considered as the first therapeutic option. Adequate microsurgical technique and anesthesiological management, along with an accurate preoperative understanding of the tumor's exact topographic origin and growth pattern, is crucial for a good surgical outcome.

The First Hundred Years of the Scientific Field of Anaesthesiology and Reanimation in the Republic of Turkey.

As a scientific field, anaesthesiology and reanimation, with their significant place in the medical structure, have been practised since the beginning of surgical procedures. Today anaesthesiology and reanimation speciality cover more complex techniques and areas than alleviating patients' pain during surgery. In the first hundred years since the proclamation of the Turkish Republic, the path covered in our scientific field is to pave the way for the next hundred years.

Surgical Treatment of Trochlear Nerve Schwannomas: Case Series and Systematic Review.

BACKGROUND AND OBJECTIVE: Cranial nerve schwannomas almost always arise from sensory or mixed nerves. Motor cranial nerves, such as the trochlear nerve, are rarely associated with schwannomas. No consensus has yet been made for surgical intervention because of the low number of reported cases of trochlear nerve schwannomas. This study comprises a systematic review of the literature and our experience for surgically treated trochlear nerve schwannomas. METHODS: Three databases (Web of Science, PubMed, and Cochrane Library) were searched without date restrictions. Studies were included if they were published in the English literature and presented patients of any age who underwent surgical treatment for trochlear schwannoma. Data extracted from the included studies were combined with our experience. RESULTS: Forty-one studies, presenting 43 patients, met the inclusion criteria. The total number of patients was 45 after our experience was added. The most common symptoms were diplopia (62.2%), headache (46.7%), and motor weakness (37.8%). Mean age during the diagnosis was 45.1 years. Although the subtemporal transtentorial approach (n = 14) is the most preferred method, its application has decreased in recent years. In the last decade, the lateral suboccipital approach (n = 11) has gained popularity. Residual postoperative trochlear nerve deficit was detected in 81% of patients. The probability of neurologic deficit was not statistically associated with tumor volume (P = 0.914), location (P = 0.669), or resection rate (P = 0.554). CONCLUSIONS: Although trochlear schwannomas are rare and their treatment involves challenges, total resection with the proper approach provides the most desirable results.

Microsurgical Treatment of Deep and Eloquent AVMs.

Over the past 30 years, the treatment of deep and eloquent arteriovenous malformations (AVMs) has moved away from microneurosurgical resection and towards medical management and the so-called minimally invasive techniques, such as endovascular embolization and radiosurgery. The Spetzler-Martin grading system (and subsequent modifications) has done much to aid in risk stratification for surgical intervention; however, the system does not predict the risk of hemorrhage nor risk from other interventions. In more recent years, the ARUBA trial has suggested that unruptured AVMs should be medically managed. In our experience, although these eloquent regions of the brain should be discussed with patients in assessing the risks and benefits of intervention, we believe each AVM should be assessed based on the characteristics of the patient and the angio-architecture of the AVM, in particular venous hypertension, which may guide us to treat even high-grade AVMs when we believe we can (and need to) to benefit the patient. Advances in imaging and intraoperative adjuncts have helped us in decision making, preoperative planning, and ensuring good outcomes for our patients. Here, we present several cases to illustrate our primary points that treating low-grade AVMs can be more difficult than treating high-grade ones, mismanagement of deep and eloquent AVMs at the behest of dogma can harm patients, and the treatment of any AVM should be tailored to the individual patient and that patient's lesion.

The posterior interhemispheric transparieto-occipital fissure approach to the atrium of the lateral ventricle: a fiber microdissection study with case series.

The surgical approach to the atrium of the lateral ventricle remains a challenge because of its deep location and close relationship to important neurovascular structures. We present an alternative and safer approach to lesions of the atrium using a natural pathway through the parieto-occipital fissure. We demonstrate this approach through cadaveric anatomical microdissection and a case series. Five formalin-fixed brain specimens (10 hemispheres) were dissected with the Klingler technique. Transillumination was used to show the trajectory of the approach in cadaveric specimens. Clinical data from five patients who underwent this approach were reviewed. This data included intraoperative ultrasound images, operative images, pre- and postoperative magnetic resonance imaging, MR tractography, and visual field examination. The parieto-occipital fissure is a constant, uninterrupted fissure that can be easily identified in cadavers. Our anatomical dissection study revealed that the atrium of the lateral ventricle can be approached through the parieto-occipital fissure with minor damage to the short association fibers between the precuneus and cuneus, and a few fibers of the forceps major. In our series, five patients underwent total resection of their atrial lesions via the posterior interhemispheric transparieto-occipital fissure. No morbidity or mortality was observed, and the disruption of white matter was minimal, as indicated on postoperative tractography. The postoperative visual fields were normal. The posterior interhemispheric transparieto-occipital fissure approach is an alternative to remove lesions in the atrium of the lateral ventricle, causing the least damage to white matter tracts and preserving visual cortex and optic radiation.

Microneurosurgical removal of thalamic lesions: surgical results and considerations from a large, single-surgeon consecutive series.

OBJECTIVE: The object of this study was to present the surgical results of a large, single-surgeon consecutive series of patients who had undergone transcisternal (TCi) or transcallosal-transventricular (TCTV) endoscope-assisted microsurgery for thalamic lesions. METHODS: This is a retrospective study of a consecutive series of patients harboring thalamic lesions and undergoing surgery at one institution between February 2007 and August 2019. All surgical and patient-related data were prospectively collected. Depending on the relationship between the lesion and the surgically accessible thalamic surfaces (lateral ventricle, velar, cisternal, and third ventricle), one of the following surgical TCi or TCTV approaches was chosen: anterior interhemispheric transcallosal (AIT), posterior interhemispheric transtentorial subsplenial (PITS), perimedian supracerebellar transtentorial (PeST), or perimedian contralateral supracerebellar suprapineal (PeCSS). Since January 2018, intraoperative MRI has also been part of the protocol. The main study outcome was extent of resection. Complete neurological examination took place preoperatively, at discharge, and 3 months postoperatively. Descriptive statistics were calculated for the whole cohort. RESULTS: In the study period, 92 patients underwent surgery for a thalamic lesion: 81 gliomas, 6 cavernous malformations, 2 germinomas, 1 metastasis, 1 arteriovenous malformation, and 1 ependymal cyst. In none of the cases was a transcortical approach adopted. Thirty-five patients underwent an AIT approach, 35 a PITS, 19 a PeST, and 3 a PeCSS. The mean follow-up was 38 months (median 20 months, range 1-137 months). No patient was lost to follow-up. The mean extent of resection was 95% (median 100%, range 21%-100%), and there was no surgical mortality. Most patients (59.8%) experienced improvement in their Karnofsky Performance Status. New permanent neurological deficits occurred in 8 patients (8.7%). Early postoperative (< 3 months after surgery) problems in CSF circulation requiring diversion occurred in 7 patients (7.6%; 6/7 cases in patients with high-grade glioma). CONCLUSIONS: Endoscope-assisted microsurgery allows for the removal of thalamic lesions with acceptable morbidity. Surgeons must strive to access any given thalamic lesion through one of the four accessible thalamic surfaces, as they can be reached through either a TCTV or TCi approach with no or minimal damage to normal brain parenchyma. Patients harboring a high-grade glioma are likely to develop a postoperative disturbance of CSF circulation. For this reason, the AIT approach should be favored, as it facilitates a microsurgical third ventriculocisternostomy and allows intraoperative MRI to be done.

Comparison of tramadol versus tramadol with paracetamol for efficacy of postoperative pain management in lumbar discectomy: A randomised controlled study.

PURPOSE: Despite developments in the treatment of pain, the availability of new drugs or increased knowledge of pain management, postoperative pain control after different surgeries remains inadequate. We aimed to compare the postoperative analgesic efficacy of tramadol versus tramadol with paracetamol after lumbar discectomy. DESIGN, SETTING, PARTICIPANTS: Sixty patients undergoing lumbar discectomy were randomly assigned into two groups. METHODS: Patients in Group T (n = 30) received tramadol (1 mg/kg), and patients in Group TP (n = 30) received tramadol (1 mg/kg) with paracetamol (1 g) 30 minutes before the end of surgery and paracetamol was continued during the postoperative period at 6 hours intervals for the first 24 hours. Patient-controlled analgesia with tramadol was used during the postoperative period. MAIN OUTCOME MEASURES: Duration, postoperative pain scores, Ramsay sedation scores, analgesic consumption, and side effects were recorded in all patients during the postoperative period. Continuous random variables were tested for normal distribution using the Kolmogorov-Smirnov test, than Student's t-test was used for means comparisons between groups. For discrete random variables chi-square tests and McNemar test was used. RESULTS: Demographic data, mean duration of anaesthesia and surgery were similar in both groups. Postoperative pain scores were significantly higher in Group T than Group TP at 5; 15; 20; and 30 minutes (P = .021, P = .004, P = .002, P = .018). Late postoperative pain scores were similar. Total tramadol consumption in Group T (106.12 ± 4.84 mg) was higher than Group TP (81.20 ± 2.53) during the 24 hours postoperative period. However, continuing the paracetamol at 6 hours interval did not change late postoperative pain scores. CONCLUSION: The administration of tramadol with paracetamol was more effective than tramadol alone for early acute postoperative pain therapy following lumbar discectomy. Therefore, while adding paracetamol in early pain management is recommended, continuing paracetamol for the late postoperative period is not advised.

Surgically Treated Status Epilepticus due to Large Cortical Tuber and Long-Term Follow-Up Results.

We present a case of invasive monitoring of a patient while he was being surgically treated in the status state. Our patient was a 27-year-old male who was hospitalized for frequent seizures, which began after a head trauma at the age of 3 years. Video electroencephalography was performed, and 25 clinical seizures were observed in 24 hours. Cranial magnetic resonance imaging (MRI) revealed a right frontal lesion which was hyperintense in T2-weighted and hypointense in T1-weighted images, and a subependymal nodule. For invasive monitoring, subdural electrodes were placed on the cortex surface via a right frontal craniotomy. The patient was re-operated, and the epileptic zone resection was performed. There was no sign of neurological deficit. Histopathological examination revealed cortical tuber, and the patient was scanned for tuberous sclerosis. There was no sign of tuberous sclerosis in other organs. The diagnosis of our patient was tuberous sclerosis, cortical tuber, subependymal nodule, epilepsy, and intermediate mental retardation. Radiological diagnosis should also be considered. Cortical tuber can be confused with focal cortical dysplasia. Finally, staged resection may be performed as a surgical treatment in some cases.

Effect of the degree of head elevation on the incidence and severity of venous air embolism in cranial neurosurgical procedures with patients in the semisitting position.

OBJECTIVE The semisitting position of a patient confers numerous advantages in various neurosurgical procedures, but venous air embolism is one of the associated complications of this position. To date, no prospective studies of the relationship between the degree of head elevation and the rate and severity of venous air embolism for patients undergoing a procedure in this position have been performed. In this study, the authors compared changes in the severity of venous air embolism according to the degree of head elevation (30° or 45°) in patients undergoing an elective cranial neurosurgical procedure in the semisitting position. METHODS One hundred patients undergoing an elective infratentorial craniotomy in the semisitting position were included, and each patient was assigned to 1 of 2 groups. In Group 1, each patient's head was elevated 30° during surgery, and in Group 2, each patient's head elevation was 45°. Patients were assigned to their group according to the location of their lesion. During surgery, the standard anesthetic protocol was used with total intravenous anesthesia, and transesophageal echocardiography was used to detect air in the blood circulation. Any air embolism seen on the echocardiography screen was classified as Grade 0 to 4. If multiple events occurred, the worst graded attack was used for statistical analysis. During hemodynamic changes caused by emboli, fluid and vasopressor requirements were recorded. Surgical and anesthetic complications were recorded also. All results were compared statistically, and a p value of < 0.05 was considered statistically significant. RESULTS There was a statistically significant difference between groups for the total rates of venous air emboli detected on transesophageal echocardiography (22.0% [n = 11] in Group 1 and 62.5% [n = 30] in Group 2; p < 0.0001). The rate and severity of air embolism were significantly lower in Group 1 than in Group 2 (p < 0.001). The rates of clinically important venous air embolism (Grade 2, 3, or 4, venous air embolism with decreased end-tidal carbon dioxide levels and/or hemodynamic changes) were 8.0% (n = 4) in Group 1 and 50.0% (n = 24) in Group 2 (p < 0.0001). There was no association between the rate and severity of venous air embolism with patient demographics (p > 0.05). An association was found, however, between the rate of venous air embolism and the type of surgical pathology (p < 0.001); venous embolism occurred more frequently in patients with a meningioma. There were no major surgical or anesthetic complications related to patient position during the postoperative period. CONCLUSIONS For patients in the semisitting position, an increase in the degree of head elevation is related directly to a higher rate of venous air embolism. With a 30° head elevation and our standardized technique of positioning, the semisitting position can be used safely in neurosurgical practice.

Comparison of Dexamethasone-Dimenhydrinate and Dexamethasone-Ondansetron in Prevention of Nausea and Vomiting in Postoperative Patients.

INTRODUCTION: Postoperative Nausea and Vomiting is one of the most common problems after implementation of general anesthesia. The incidence can reach 80% in high-risk patients, depending on the type of surgery. In our study, we aimed to compare dexamethasone-dimenhydrinate and dexamethasone-ondansetron combinations in prevention of nausea and vomiting in postoperative patients. METHOD: Sixty 18-65-year-olds ASAI-II females who underwent rhinoplasty were included in the study. Patients were randomly included in two groups: Dexamethasone-dimenhydrinate group (group DD) and dexamethasone-ondansetron group (group DO). All patients received dexamethasone 8 mg iv after endotracheal intubation. Anesthesia continuation was established with sevoflurane, air-oxygen mixture and remifentanil infusion. At the 30th minute of the operation, group DO received ondansetron 4 mg iv and group DD received dimenhydrinate 1 mg/kg iv. For postoperative analgesia tramadol (1.5 mg/kg) iv, tenoksikam (20 mg) and afterward for postoperative patient-controlled tramadol was used. In the postoperative recovery room, nausea and vomiting were evaluated at the 30th, 60th, 120th minutes and at the end of 24 h. Total amount of tramadol was recorded. All results were statistically evaluated. OBSERVATIONS: Demographics and Apfel risk scores of both groups were similar. Surgical operation duration (p = 0.038) and total preoperative remifentanil consumption were higher in group DD (p = 0.006). In group DO, nausea at 30 and 60 min (p = 0.001, p = 0.007), retching at 30 and 60 min (p = 0.002, p = 0.006) were higher than group DD. The additional antiemetic need in group DO was significantly higher at 30 min (p = 0.001). Postoperative analgesic consumption was similar in both groups. RESULT: Our study revealed that dexamethasone-dimenhydrinate combination was more effective than dexamethasone-ondansetron in prevention of nausea and vomiting after rhinoplasty operations. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Efficacy of placing a thin layer of gelatin sponge over the subdural space during dural closure in preventing meningo-cerebral adhesion.

OBJECTIVE: One significant drawback during a cranial reoperation is the presence of meningocerebral adhesions. The appearance of connective tissue bridges between the inner surface of the dura and the pia-arachnoid is mostly related to dural closure and the condition in which the surgical field was left in the previous surgery. This study was done to determine the benefit of placing a thin-layer gelatin sponge of polypeptides subdurally to prevent meningocerebral adhesions. METHODS: From September 2005 through May 2012, 902 craniotomies were performed for various lesions by the senior author (U.T.). Beginning in February 2009, we began placing a gelatin sponge under the dural flap to isolate the dural healing process from the cortical surface. To compare the degree of meningocerebral adhesions statistically, reoperation cases between February 2009 and May 2012 were divided into 2 groups as group G (gelatin) and group C (Control) in which the dural closure was made with and without subdural application of the gelatin sponge, respectively. RESULTS: In all patients of group G (n = 15), a neomembrane was found when the dura was opened. This layer was easily dissected and showed no or minimal attachment to the underlying cerebral cortex. However, in group C (n = 14), meningocerebral adhesions in various degrees were detected. Adhesion scores were significantly greater in group C than in group G (P < 0.001). CONCLUSION: This study proves that, during the dural closure, placing a thin layer of gelatin sponge in the subdural space is a safe and effective method for preventing meningocerebral adhesions.

The paramedian supracerebellar-transtentorial approach to the entire length of the mediobasal temporal region: an anatomical and clinical study. Laboratory investigation.

OBJECT: The exploration of lesions in the mediobasal temporal region (MTR) has challenged generations of neurosurgeons to achieve an appropriate approach. To address this challenge, the extensive use of the paramedian supracerebellar-transtentorial (PST) approach to expose the entire length of the MTR, as well as the fusiform gyrus, was investigated. METHODS: The authors studied the microsurgical aspects of the PST approach in 20 cadaver brains and 5 cadaver heads under the operating microscope. They evaluated the features, advantages, difficulties, and limitations of the PST approach and refined the surgical technique. They then used the PST approach in 15 patients with large intrinsic MTR tumors (6 patients), tumor in the posterior fusiform gyrus with mediobasal temporal epilepsy (MTE) (1 patient), cavernous malformations in the posterior MTR including the fusiform gyrus (2 patients), or intractable MTE with hippocampal sclerosis (6 patients) from December 2007 to May 2010. Patients ranged in age from 11 to 63 years (mean 35.2 years), and in 9 patients (60%) the lesion was located on the left side. RESULTS: In all patients with neuroepithelial tumors or cavernous malformations, the lesions were completely and safely resected. In all patients with intractable MTE with hippocampal sclerosis, the anterior two-thirds of the parahippocampal gyrus and hippocampus, as well as the amygdala, were removed selectively through the PST approach. There was no surgical morbidity or mortality in this series. Three patients (20%) with high-grade neuroepithelial tumors underwent postoperative radiotherapy and chemotherapy but needed a second surgery for recurrence during the follow-up period. In all patients with MTE, antiepileptic medication could be decreased to a single drug at lower doses, and no seizure activity has occurred until this point. CONCLUSIONS: The PST approach provides the surgeon precise anatomical orientation when exposing the entire length of the MTR, as well as the fusiform gyrus, for removing any lesion. This is a novel technique especially for removing tumors involving the entire MTR in a single session without damaging neighboring neural or vascular structures. This approach can also be a viable alternative for selective removal of the parahippocampal gyrus, hippocampus, and amygdala in patients with MTE due to hippocampal sclerosis.

Effects of hydroxyzine-midazolam premedication on sevoflurane-induced paediatric emergence agitation: a prospective randomised clinical trial.

BACKGROUND AND AIM: Anaesthesia with sevoflurane leads to a high prevalence of emergence agitation in paediatric patients. This study investigates the effects of combining hydroxyzine and midazolam on sevoflurane-induced emergence agitation in paediatric patients undergoing infraumbilical surgery with a caudal block. PATIENTS AND METHODS: Eighty-four children 1-7 years of age undergoing general anaesthesia with sevoflurane and caudal block were assigned to two groups. Children in group M (n = 42) were premedicated with 0.5 mg kg oral midazolam and children in group MH (n = 42) were premedicated with 0.5 mg kg oral midazolam and 1 mg kg hydroxyzine given 30 min before anaesthesia induction. A caudal epidural block was performed following anaesthesia induction. Induction quality, parental separation scores and emergence agitation were evaluated. Emergence agitation was evaluated with the PAED score (Paediatric Anesthesia Emergence Delirium) every 5 min during the first 30 min after admission to recovery room. Induction quality and parental separation were assessed with 4-point scores. Postoperative pain was evaluated with the 10-point Children's and Infants' Postoperative Pain Scale. RESULTS: Median parental separation (3 vs. 2; P = 0.01), induction quality (2 vs. 2; P = 0.03) and sedation scores (3 vs. 2; P = 0.003) were significantly better in the MH group compared to the M group. Median PAED score of group M (15) was higher than that of group MH (11; P < 0.001) and the number of children with PAED scores more than 16 was also higher in group M (n = 16) compared to group MH (n = 2; P < 0.001). None of the children had a pain score more than 3 throughout the study period. CONCLUSION: The incidence of sevoflurane-induced emergence agitation was significantly lower in children premedicated with a midazolam and hydroxyzine combination compared to those premedicated with midazolam only. Furthermore, the midazolam and hydroxyzine combination provided better premedication quality than midazolam alone.

Dexmedetomidine as an adjunct to anesthetic induction to attenuate hemodynamic response to endotracheal intubation in patients undergoing fast-track CABG.

During induction of general anesthesia hypertension and tachycardia caused by tracheal intubation may lead to cardiac ischemia and arrhythmias. In this prospective, randomized study, dexmedetomidine has been used to attenuate the hemodynamic response to endotracheal intubation with low dose fentanyl and etomidate in patients undergoing myocardial revascularization receiving beta blocker treatment. Thirty patients undergoing myocardial revascularization received in a double blind manner, either a saline placebo or a dexmedetomidine infusion (1 microg/kg) before the anesthesia induction. Heart rate (HR) and blood pressure (BP) were monitored at baseline, after placebo or dexmedetomidine infusion, after induction of general anesthesia, one, three and five minutes after endotracheal intubation. In the dexmedetomidine (DEX) group systolic (SAP), diastolic (DAP) and mean arterial pressures (MAP) were lower at all times in comparison to baseline values; in the placebo (PLA) group SAP, DAP and MAP decreased after the induction of general anesthesia and five minutes after the intubation compared to baseline values. This decrease was not significantly different between the groups. After the induction of general anesthesia, the drop in HR was higher in DEX group compared to PLA group. One minute after endotracheal intubation, HR significantly increased in PLA group while, it decreased in the DEX group. The incidence of tachycardia, hypotension and bradycardia was not different between the groups. The incidence of hypertension requiring treatment was significantly greater in the PLA group. It is concluded that dexmedetomidine can safely be used to attenuate the hemodynamic response to endotracheal intubation in patients undergoing myocardial revascularization receiving beta blockers.

The analgesic effect of gabapentin as a prophylactic anticonvulsant drug on postcraniotomy pain: a prospective randomized study.

BACKGROUND: Gabapentin is an anticonvulsant drug that has analgesic properties for acute postoperative pain. However, the analgesic effect of gabapentin as an antiepileptic prophylactic drug on patients undergoing craniotomy is unclear. In this study, we evaluated the postoperative effectiveness of gabapentin on acute postoperative pain when it is used for antiepileptic prophylaxis in patients undergoing craniotomy for supratentorial tumor resection. METHODS: Eighty patients undergoing craniotomy for supratentorial tumor resection were randomly assigned into two groups. Patients in Group G (n = 40) received oral gabapentin (3 x 400 mg), and patients in Group P (n = 40) received oral phenytoin (3 x 100 mg) for 7 days before the operation and postoperatively. An identical anesthesia protocol was performed for both the groups. Anesthesia was maintained with propofol and remifentanil infusion. Patient-controlled analgesia with morphine was used, and pain levels were measured. The antiepileptic-related side effects, anesthetic consumption, duration of anesthesia and surgery, tracheal extubation time, postoperative pain scores, morphine consumption, and sedation scores were recorded. RESULTS: Thirty-seven patients in Group G and 38 patients in Group P completed the study. During the preoperative period in Group G, one patient had severe fatigue, one had severe dizziness, and one patient's surgical procedure was changed. The median plasma levels of gabapentin were 34 micromol/mL (range, 23-51 micromol/mL) in 34 patients. In Group P, one patient withdrew from the study preoperatively and one developed transient neurological symptoms postoperatively. The demographic data and mean duration of anesthesia and surgery were similar in both the groups. The total propofol and remifentanil consumption in Group G (1847 +/- 548 mg/3034 +/- 1334 microg) was significantly less than that of Group P (2293 +/- 580 mg/4287 +/- 1282 microg) (P = 0.01). However, tracheal extubation could be done earlier in Group P (4.5 +/- 2 min) than in Group G (16.6 +/- 22 min) (P < 0.001). Pain scores were significantly higher in Group P at 15 min, 30 min, and 1 h (P < 0.001). The total morphine consumption was also significantly higher in Group P (33 +/- 17 mg vs 24 +/- 19 mg) (P = 0.01). The postoperative sedation scores were significantly higher in Group G at 15 min, 30 min, 1 h, and 2 h (P < 0.001). CONCLUSIONS: The administration of gabapentin to patients undergoing craniotomy for supratentorial tumor resection was effective for acute postoperative pain. It also decreased analgesic consumption after surgery. However, it may lead to side effects such as delayed tracheal extubation and increased sedation postoperatively.

The effects of propofol infusion on hepatic and pancreatic function and acid-base status in children undergoing craniotomy and receiving phenytoin.

BACKGROUND: In this study, we investigated the effects of propofol infusion on hepatic and pancreatic enzymes and acid-base status compared with baseline values in children undergoing craniotomy who were receiving phenytoin for antiepileptic prophylaxis. METHODS: In this prospective clinical study, we measured the serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transpeptidase (GGT), alkaline phosphatase (ALP), pancreatic amylase, lipase, and triglyceride levels of 30 children ranging from 4 to 12 yr. All children received propofol anesthesia and were taking phenytoin for antiepileptic prophylaxis. Patients already receiving phenytoin were continued on their medication. Peroral 5 mg x kg(-1) x d(-1) phenytoin was started in patients who were not receiving phenytoin. Serum AST, ALT, GGT, ALP, bilirubin, pancreatic amylase, lipase, and triglyceride levels were studied on admission to the hospital, 1 day before surgery, and on postoperative Days 1, 3, 5, and 7. Arterial blood gas samplings were taken after tracheal intubation, during the operation (2nd and 4th h), just after extubation, and 1, 2, 6, and 12 h after extubation. RESULTS: Serum AST, ALT, GGT, ALP, pancreatic amylase, lipase, and triglyceride levels were increased significantly in the postoperative period compared with baseline with a peak value on postoperative Day 1 and returned to normal values within a week. Base excess levels after extubation were significantly decreased compared with baseline. They were in the normal range, however, and returned to baseline values by 6 h after surgery. There were no clinical signs of hepatitis or pancreatitis. Bilirubin levels were normal. None of the children developed complications related to the liver or pancreas during the 4-6 mo after surgery. CONCLUSIONS: Despite the slightly increased pancreatic and hepatic enzyme levels during the postoperative period, anesthesia maintenance with propofol in children undergoing craniotomy had no significant clinical effect on the acid-base status or pancreas or liver enzymes.

Comparison of the effect of sevoflurane and halothane anesthesia on the fall in heart rate as a predictor of successful single shot caudal epidural in children.

OBJECTIVE: To investigate the effect of sevoflurane anesthesia on heart rate HR fall with the injection of the initial drug in caudal space to confirm the correct needle placement. METHODS: After the ethical approval was obtained from the hospital's ethics committee, a prospective, randomized, clinical study was designed in Yeditepe University Hospital, in 2007. Children aged 1-12 years, scheduled for infraumbilical surgery under general anesthesia, and caudal block were included in the study. Anesthesia was induced, and maintained by sevoflurane in group S (n=85), and by halothane in group H (n=82). Baseline HR was recorded before the caudal block was performed. The HR changes during the initial dose, and total drug injection were recorded followed by 2 more HR recordings taken 5, and 10 minutes after caudal injection. The success of the block was recorded by a blind observer. RESULTS: There were 167 children included in the study. Caudal block success was 96.5% in group S, and 97.6% in group H. Basal HR was 110.9 +/- 10.9 in group S, and 105.9 +/- 10.1 in group H. Following the initial drug injection, mean HR was 109.8 +/- 10.9 in group S, and 102.9 +/- 9.9 in group H. It was significantly lower than the baseline in group H. The only significant decrease in the HR of the patients in group S was at the tenth minute following caudal injection. CONCLUSION: The decrease in HR with drug injection has no value to predict the success of caudal block under sevoflurane anesthesia.

Spinal accessory nerve monitoring in posterior fossa surgery.

The role of intraoperative monitoring of lower cranial nerves is not well established. In this study, the authors retrospectively analyzed the intraoperative monitoring data and the clinical outcome of the spinal accessory nerve (SAN) in patients who have undergone posterior fossa surgery. SAN was monitored in 19 patients. Subcutaneous needle electrodes were placed in the trapezius, and any abnormal spontaneous activity was documented for duration and amplitude. A bipolar stimulation probe was used for triggered electromyogram, with a maximum stimulation intensity of 3 mA. All patients were clinically evaluated for SAN dysfunction postoperatively 24 hours and 7 days. Neurotonic discharges, lasting between 3 and 90 minutes were seen in 84% of the patients. Continuous discharges lasting longer than 5 minutes were seen in 36% of the patients. The SAN was stimulated in 57.8% of the patients. With clinical examination, none of our patients had postoperative SAN dysfunction. Long lasting dense neurotonic discharges and high stimulation thresholds have been correlated with postoperative facial nerve injury; however, this does seem be true in the case of SAN monitoring. Neurotonic discharges are commonly false-positive and stimulation intensity up to 3 mA can be related with a good outcome. The intraoperative monitoring of SAN may not be valuable as much as facial nerve monitoring.

Internal jugular vein diameter in pediatric patients: are the J-shaped guidewire diameters bigger than internal jugular vein? An evaluation with ultrasound.

AIM: This study investigates whether the diameters of right internal jugular vein (RIJV) are suitable for the use of 'big radius curved J-tip' Seldinger wires in pediatric patients. METHODS: One-hundred and thirty-five children, 1 month to 15 years of age, scheduled for pediatric surgery were divided into four subgroups according to their age (0-12 months, 1-2 years, 2-6 years old, and >6 years). Patients in the 0-12 months group were further divided into two groups as 0-6 months and 7-12 months of age to evaluate RIJV characteristics in detail. Following anesthesia induction, depth, diameter, and area of RIJV were measured with ultrasound at the level of cricoid cartilage and sterno-clavicular junction in supine and Trendelenburg position. RESULTS: Infants in the 0-6 months of age group had the least mean diameter of RIJV at both the cricoid cartilage and the sternoclavicular junction level (0.484 +/- 0.132 and 0.499 +/- 0.136 cm). The aforementioned diameter was significantly lower than the values of other age groups (P < 0.05). Trendelenburg position did not increase RIJV diameter in children below 6 and cross-sectional area below 2 years old. Correlations between age, height, weight, head circumference and RIJV diameter, cross-sectional area, depth from the skin were weak. CONCLUSION: The diameter of the IJV in pediatric patients, especially infants, is often smaller than the diameter of the J-tip guidewire curve. We speculate that this may lead to impeded guidewires and failed cannulation. It must also be kept in mind that the Trendelenberg position might not facilitate IJV cannulation in children <2 years of age.