Kotoe Kamata

Airway Scope and gum elastic bougie with Macintosh laryngoscope for tracheal intubation in patients with simulated restricted neck mobility

BACKGROUND /st> Airway Scope is a new videolaryngoscope which requires less cervical movement during intubation than direct laryngoscopy. Thus, in patients wearing a rigid cervical collar, we compared the efficacy of the Airway Scope and the gum elastic bougie with Macintosh laryngoscope during tracheal intubation. METHODS /st> Anaesthesia was induced with propofol, fentanyl, and rocuronium. A rigid cervical collar was applied, and patients were randomly assigned to tracheal intubation with an Airway Scope (n=48) or multiple-use gum elastic bougie with Macintosh laryngoscope (n=48). Measurements included intubation time, gum elastic bougie insertion time, intubation success rate, and insertion and intubation attempts. Airway complications were also recorded. RESULTS /st> The time required for successful intubation was significantly shorter with the Airway Scope compared with the gum elastic bougie with Macintosh laryngoscope [mean (sd) 34 (13) vs 49 (27) s, P=0.001], although the overall success rate of the Airway Scope (100%) compared with the gum elastic bougie with Macintosh laryngoscope (90%) did not reach the statistical significance (P=0.056). Oesophageal intubation (n=8) occurred only with the gum elastic bougie with Macintosh laryngoscope. Incidence of mucosal trauma and lip injury was similar with each device. No dental injury or hypoxia occurred with either device. CONCLUSIONS /st> The Airway Scope shortens intubation time, is less likely to result in oesophageal intubation, and may offer a marginally higher intubation success rate in patients with simulated restricted neck mobility.

Functional evidence for presence of lipid rafts in erythrocyte membranes: Gsα in rafts is essential for signal transduction

Membrane microdomains enriched in cholesterol and sphingolipids and containing specific membrane proteins are designated as lipid rafts. Lipid rafts have been implicated in cell signaling pathways in various cell types. Heterotrimeric guanine nucleotide‐binding protein (Gsα) has been shown to be a raft component of erythrocytes and has been implicated in cell signaling. Rafts are isolated as detergent‐resistant microdomains (DRMs) for biochemical analysis. Cholesterol depletion is widely used to disrupt raft structures to study their function in biological membranes. In the present study, we developed an alternate strategy for disrupting raft structures without altering membrane cholesterol content. Lidocaine hydrochloride, an amphipathic local anesthetic, is shown to reversibly disrupt rafts in erythrocyte membranes and alter the Gsα dependent signal transduction pathway. These findings provide evidence for the presence of rafts while maintaining normal cholesterol content in erythrocyte membranes and confirm a role for raft‐associated Gsα in signal transduction in erythrocytes. Am. J. Hematol., 2008.

Airway scope and StyletScope for tracheal intubation in a simulated difficult airway.

BACKGROUND: Direct laryngoscopy is difficult when the cervical spine is immobilized. The Airway Scope® and StyletScope® are new laryngoscopes designed to facilitate intubation under these circumstances. Thus, in patients wearing a rigid cervical collar to simulate a difficult airway, we tested the hypothesis that the intubation success rates of the Airway Scope and StyletScope are similar, but that intubation with Airway Scope is faster. METHODS: Adult patients requiring tracheal intubation as part of anesthesia were enrolled. After anesthesia induction and muscle relaxation, patients’ necks were stabilized with a rigid Philadelphia collar and patients were randomly assigned to tracheal intubation with Airway Scope (n = 50) or StyletScope (n = 50). Overall intubation success rate, time required for intubation, the number of attempts required for successful intubation, and airway complications related to intubation were recorded. RESULTS: Overall intubation success rates were 98% with Airway Scope and 96% with StyletScope. Intubation was 19 s faster with Airway Scope (32[8] s; mean) versus StyletScope (51[29] s). The number of required intubation attempts was similar with each device: 26/18/5 (first/second/third attempt) for Airway Scope versus 26/17/5 for StyletScope. The incidence of mucosal trauma and lip injury was similar, except esophageal intubation occurred only with StyletScope (n = 6); neither dental injury nor hypoxia occurred. CONCLUSIONS: Both the Airway Scope and StyletScope offer high success rates in a simulated difficult airway achieved by a rigid collar. However, the Airway Scope is faster and less likely to cause esophageal intubation.

Airway scope and Macintosh laryngoscope for tracheal intubation in patients lying on the ground.

BACKGROUND: Direct laryngoscopy of a patient lying on the ground is difficult because the intubators head is far above the head of the patient, making alignment of the intubators visual axis with the patients tracheal axis difficult. The Airway Scope is a laryngoscope designed to facilitate tracheal intubation without requiring alignment of the oral, pharyngeal, and tracheal axes. We thus tested the hypothesis that intubation with the Airway Scope is faster than with the Macintosh laryngoscope in subjects lying on the ground. METHODS: Adult surgical patients were enrolled. After anesthesia induction, direct laryngoscopy was performed and airway characteristics noted. Patients were randomly assigned to tracheal intubation by either the Airway Scope (n = 50) or the Macintosh laryngoscope (n = 50). The intubator performed tracheal intubation from a table positioned at the same height as that of the operating table, thus simulating intubating on the ground. An unblinded observer recorded overall intubation success rate, time required for intubation, the number of attempts required for successful intubation, and airway complications related to intubation. Of these, the primary end point was time required for intubation. RESULTS: Overall intubation success rates were 98% with the Airway Scope and 100% with the Macintosh laryngoscope. Intubation was 17 s faster with the Airway Scope (mean, 18 (SD, 4) seconds) versus the Macintosh laryngoscope (35 (16) seconds). The number of intubation attempts was similar with each device. The incidences of airway complications were similar, with no hypoxia (SpO2 <95%) occurring in either group. CONCLUSIONS: Both the Airway Scope and the Macintosh laryngoscope offer high success rates in adequately prepared paralyzed patients lying supine at ground level in the hands of a skilled practitioner. However, the Airway Scope facilitated faster tracheal intubation.

Difficulty in identification of the frontal language area in patients with dominant frontal gliomas that involve the pars triangularis

OBJECTIVE Identification of language areas using functional brain mapping is sometimes impossible using current methods but essential to preserve language function in patients with gliomas located within or near the frontal language area (FLA). However, the factors that influence the failure to detect language areas have not been elucidated. The present study evaluated the difficulty in identifying the FLA in dominant-side frontal gliomas that involve the pars triangularis (PT) to determine the factors that influenced failed positive language mapping. METHODS Awake craniotomy was performed on 301 patients from April 2000 to October 2013 at Tokyo Womens Medical University. Recurrent cases were excluded, and patients were also excluded if motor mapping indicated their glioma was in or around the motor area on the dominant or nondominant side. Eighty-two consecutive cases of primary frontal glioma on the dominant side were analyzed for the present study. MRI was used for all patients to evaluate whether tumors involved the PT and to perform language functional mapping with a bipolar electrical stimulator. Eighteen of 82 patients (mean age 39 ± 13 years) had tumors that showed involvement of the PT, and the detailed characteristics of these 18 patients were examined. RESULTS The FLA could not be identified with intraoperative brain mapping in 14 (17%) of 82 patients; 11 (79%) of these 14 patients had a tumor involving the PT. The negative response rate in language mapping was only 5% in patients without involvement of the PT, whereas this rate was 61% in patients with involvement of the PT. Univariate analyses showed no significant correlation between identification of the FLA and sex, age, histology, or WHO grade. However, failure to identify the FLA was significantly correlated with involvement of the PT (p < 0.0001). Similarly, multivariate analyses with the logistic regression model showed that only involvement of the PT was significantly correlated with failure to identify the FLA (p < 0.0001). In 18 patients whose tumors involved the PT, only 1 patient had mild preoperative dysphasia. One week after surgery, language function worsened in 4 (22%) of 18 patients. Six months after surgery, 1 (5.6%) of 18 patients had a persistent mild speech deficit. The mean extent of resection was 90% ± 7.1%. Conclusions Identification of the FLA can be difficult in patients with frontal gliomas on the dominant side that involve the PT, but the positive mapping rate of the FLA was 95% in patients without involvement of the PT. These findings are useful for establishing a positive mapping strategy for patients undergoing awake craniotomy for the treatment of frontal gliomas on the dominant side. Thoroughly positive language mapping with subcortical electrical stimulation should be performed in patients without involvement of the PT. More careful continuous neurological monitoring combined with subcortical electrical stimulation is needed when removing dominant-side frontal gliomas that involve the PT.

Initial Experience with the Use of Remote Control Monitoring and General Anesthesia during Radiosurgery for Pediatric Patients

The demand for general anesthesia in pediatric radiosurgery has been increasing, but the issues involved are not highlighted well in the medical literature. We developed remotely controlled monitoring and anesthesia techniques, and applied our system to three pediatric patients who underwent Gamma Knife radiosurgery with automated settings. Based on the perioperative safety management, the following issues are of considerable concern: to avoid emotional trauma associated with the treatment, to secure airway patency in a variety of head positions, and to apply all standard monitors. In this report, we describe the details of our project with a comprehensive literature review.

How to Control Propofol Infusion in Pediatric Patients Undergoing Gamma Knife Radiosurgery

INTRODUCTION Although Gamma Knife radiosurgery (GKS) is commonly performed under local anesthesia, general anesthesia is sometimes required. The authors previously reported a remote-controlled patient management system consisting of propofol-based general anesthesia with a target-controlled infusion (TCI) that we designed for pediatric GKS. However, a commercially available propofol TCI system has age and weight limitations (<16 years and <30 kg). We examined a manually controlled regimen of propofol appropriate for pediatric GKS. METHODS A pharmacokinetic model of the TIVA Trainer© with Paedfusors parameter was used. A manually controlled infusion scheme to achieve a sufficient level of propofol for pediatric GKS was examined in five models ranging from 10 to 30 kg. RESULTS Following a loading dose of 3.0 mg/kg, the combination of continuous infusion of 14, 12, 10, and 8 mg/kg/h resulted in a target concentration of 3.0-4.0 μg/ml, the required level for pediatric GKS. CONCLUSION Propofol titration is a key issue in GKS. Manual infusion is less accurate than TCI, but the combination of a small bolus and continuous infusion might be a substitute. Considering the characteristics of propofol pharmacokinetics in children, co-administration of opioids is recommended.

Epidural anesthesia for cesarean delivery in a parturient with a double-outlet right ventricle

drine. At the end of anesthesia, BP was 130/70 mmHg, HR was 54 bpm, SpO2 was 81%, and CVP was 8mmHg, and the anesthetic block remained at the Th7 level by a cold test. Anesthesiologists prefer regional anesthesia (RA) rather than general anesthesia (GA) for the management of CS. Although it has been reported that maternal deaths due to complications induced by the anesthesia for CS were more frequent in patients receiving GA than in those receiving RA [4], it is recognized that RA poses the risk of the sudden onset of severe hypotension, due to extensive vasodilatation. From this point of view, epidural anesthesia was chosen in our patient. We knew that combined spinal-epidural anesthesia for CS had already been reported in a patient with palliated DORV [3], but we regard epidural anesthesia as a favorable technique, because it can provide an appropriate state of analgesia in slow incremental steps compared to spinal anesthesia. In our patient, maternal hemodynamics were kept quite stable, apart from a stage of slight maternal hypotension just after delivery when the maternal mental stress was relieved. This fluctuation in blood pressure was not considered to be related to our anesthesia method, because this kind of hypotension is quite usual during anesthesia. Moreover, this hypotension was minimized by the use of a vasopressor in conjunction with appropriate fluid administration.

Postoperative management with dexmedetomidine in a pregnant patient who underwent AVM nidus removal: a case report

BackgroundFollowing cerebral arteriovenous malformation (AVM) surgery, severe brain edema and hemorrhage may be caused by postoperative normal perfusion pressure breakthrough (NPPB). Sedation is necessary for this population. It is a challenge for the anesthesiologist to maintain hemodynamic stability without interfering with the neurological assessment. In Japan, propofol is contraindicated for pregnant patients. Dexmedetomidine is a versatile drug in anesthesia practice and may be useful for this situation. There is no report using dexmedetomidine for the purpose of NPPB control in pregnant patients. We describe the postoperative management with dexmedetomidine for a pregnant patient who underwent cerebral AVM nidus removal.Case presentationA 32-year-old patient presented with headache at the 16th week of gestation. Neuroimaging revealed an intraventricular hemorrhage and an AVM at the right anterior horn of the lateral ventricle which caused bleeding. A multidisciplinary team discussion was done, and then a craniotomy for AVM nidus removal was performed under general anesthesia. Preanesthetic aspiration prophylaxis and rapid sequence induction were added to our conventional anesthetic management. Hypotension occurred after anesthetic induction but the patient recovered by volume resuscitation and vasopressors. Anesthesia was maintained with 50% O2 in air and sevoflurane. The AVM was completely removed, and no perioperative complications occurred. Postoperative sedation with dexmedetomidine was used to prevent breakthrough hyperperfusion and cerebral edema.ConclusionsDexmedetomidine infusion was used for postoperative sedation without causing any side effects, and it can be an alternative for sedation, especially when propofol is contraindicated.

A case of loss of consciousness with contralateral acute subdural haematoma during awake craniotomy

We are reporting the case of a 56-year-old woman who developed loss of consciousness during awake craniotomy. A thin subdural haematoma in the contralateral side of the craniotomy was identified with intraoperative magnetic resonance imaging and subsequently removed. Our case indicates that contralateral acute subdural haematoma could be a cause of deterioration of the conscious level during awake craniotomy.