The Lower Infusion Rate of Glucose to Maintain Ketogenesis within Normal Level during Surgery

Background: Intraoperative low-dose glucose infusions suppress ketogenesis and attenuate postoperative insulin resistance (IR). However, the appropriate rate for intraoperative glucose infusion remains unclear, although a postoperative infusion of 0.08 g/kg/h effectively suppressed ketogenesis at the next morning. Therefore, we investigated the effects of an intraoperative rate of 0.08 g/kg/h on ketogenesis and postoperative IR. Methods: The present study included 15 patients who were undergoing maxillofacial surgery. The patients received glucose-free Ringer’s solution and a continuous glucose infusion (0.08 g/kg/h) during the surgery. Blood samples were collected to evaluate the concentrations of noradrenaline, cortisol, glucose, insulin, ketone bodies, and free fatty acid before anesthesia induction (T1), at 1 h after induction (T2), at 3 h after induction (T3), and at the end of surgery (T4). The glucose clamp test was performed on the days before and after surgery using the STG-55TM device. IR was quantified using the mean glucose infusion rate (M-value). Results: All 15 patients exhibited intraoperative blood glucose concentrations of 90 - 130 mg/dL. There was a non-significant trend towards higher plasma concentrations of total ketone bodies at T3 (p = 0.058). The plasma concentrations of acetoacetic acid at T3 and T4 were significantly higher than that at T1 (p = 0.0217 and p = 0.0306, respectively). All patients exhibited lower M-values after surgery (mean reduction: 48.0% ± 17.9%). Conclusion: Continuous intraoperative glucose at 0.08 g/kg/h helped maintain blood glucose concentrations, although it may suppress the ketogenesis to increase during surgery.

Remifentanil Has Sufficient Hypnotic and Amnesic Effect for Induction of Anesthesia by Itself

With a small-dose remifentanil, some patients showed no reaction and did not remember it postoperatively. We, therefore, hypothesized that remifentanil may decrease the level of consciousness and/or exhibit amnesic effect when stimulations are avoided. Thirty-patients were divided into two groups: non-stimulation group and stimulation group. Anesthesia was induced with 1 micro-g·kg?1·min?1 of remifentanil using no additional hypnotic agent. In the non-stimulation group, patients were left free from any stimulation except non-invasive blood pressure monitoring. In the stimulation group, patients were asked to follow verbal commands. The level of consciousness was evaluated with electroencephalogram and BIS-value derived from it. In the non-stimulation group, all patients reached the decreased level of consciousness in 5 minutes. In the stimulation group, however, 14 patients were judged to be still conscious. 10 patients could open their mouth at the 5th minute, but 9 of these 10 patients did not remember it postoperatively. In conclusion, remifentanil, with no additional anesthetics, exhibited hypnotic and amnesic effects when stimulations were kept minimal.

Autonomic and cardiovascular effects of pentobarbital anesthesia during trigeminal stimulation in cats

Stimulation of the trigeminal nerve can elicit various cardiovascular and autonomic responses;however,the effects of anesthesia with pentobarbital sodium on these responses are unclear.Pentobarbital sodium was infused intravenously at a nominal rate and the lingual nerve was electrically stimulated at each infusion rate.Increases in systolic blood pressure（SBP） and heart rate（HR） were evoked by lingual nerve stimulation at an infusion rate between 5 and 7 mg？kg 21 ？h 21.This response was associated with an increase in the low-frequency band of SBP variability（SBP-LF）.As the infusion rate increased to 10 mg？kg 21 ？h 21 or more,decreases in SBP and HR were observed.This response was associated with the reduction of SBP-LF.In conclusion,lingual nerve stimulation has both sympathomimetic and sympathoinhibitory effects,depending on the depth of pentobarbital anesthesia.The reaction pattern seems to be closely related to the autonomic balance produced by pentobarbital anesthesia.

Effects of Propofol on Glutamate-Induced Calcium Mobilization in Presynaptic Boutons of Rat Hippocampal Neurons

Recent reports have suggested that various general anesthetics affect presynaptic processes in the central nervous system. However, characterizations of the influence of intravenous anesthetics on neurotransmitter release from presynaptic nerve terminals (boutons) are insufficient. Because the presynaptic calcium concentration ([Ca2+]pre) regulates neurotransmitter release, we investigate the effects of the intravenous anesthetic propofol on neurotransmitter release by measuring [Ca2+]pre in the presynaptic boutons of individual dissociated hippocampal neurons. Brain slices were prepared from Sprague–Dawley rats (10 - 14 days of age). The hippocampal CA1 area was isolated with a fire-polished glass pipette, which vibrated horizontally to dissociate hippocampal CA1 neurons along with their attached presynaptic boutons. Presynaptic boutons were visualized under a confocal laser scanning microscope after staining with FM1-43 dye, and [Ca2+]pre was measured using fluo-3 AM dye. Glutamate (3 – 100 μM) administration increased [Ca2+]pre in Ca2+- containing external solution in a concentration-dependent manner. Propofol (3 – 30 μM) dose-dependently suppressed this glutamate (30 μM)-induced increase in [Ca2+]pre in boutons attached to dendrites, but not to the soma or base of the dendritic tree. The large majority of excitatory synapses on CA1 neurons are located on dendritic spines;therefore, propofol may affect glutamate-induced Ca2+ mobilization in excitatory, but not inhibitory, presynaptic boutons. Propofol may possibly have some effect on glutamate-regulated neurotransmitter release from excitatory presynaptic nerve terminals through inhibiting the increase in [Ca2+]pre induced by glutamate.

Airway Management for Treacher Collins Syndrome with Limited Mouth Opening

Patients with Treacher Collins Syndrome (TCS) present unique airway management problems for anesthesiologists due to mandibular micrognathia, the small oral aperture, and temporomandibular joint anomalies. We describe the case of a pediatric TCS patient with limited mouth opening who experienced severe airway obstruction during deep inhalation anesthesia (sevoflurane following i.v. midazolam) for routine dental work. When difficult airway management is expected, intubation of conscious patients is a well-recognized technique in adults;however, it is rarely appropriate for pediatric patients who usually do not cooperate. According to general anesthesia algorithms for pediatric patients with difficult airways, in most pediatric patients, tracheal intubation is performed after the induction of general anesthesia and some authors have reported the usefulness of LMA for maintaining airway patency in patients with TCS. However, in our case LMA could not be used because of severe limitation of mouth opening. In addition, the LMA is so bulky that it is impossible to insert a LMA into patients with narrow airway anatomy. We initially planned to carry out fiber-optic intubation while awake and under sedation if the airway patency could not be secured after the induction of anesthesia. The patient was sedated properly with midazolam and sevoflurane, and awake fiberoptic intubation was performed uneventfully. Our experience in this case highlighted that careful planning of backup contingencies is important in achieving fiberoptic intubation and maintaining airway patency in pediatric TCS patients with limited mouth opening, and that awake intubation can be successful even in pediatric patients.

Unexpected Airway Obstruction Caused by Bilateral Hypoglossal Nerve Palsy Following Second Radical Neck Dissection

A 67-year-old woman underwent right radical neck dissection for cervical lymph node metastasis from maxillary gingival carcinoma. Two months later, metastasis in the left superior internal jugular lymph nodes were discovered, and left radical neck dissection was performed. Postoperatively, airway obstruction occurred despite performing extubation after confirming that the patient had fully recovered from anesthesia. Bilateral hypoglossal nerve palsy was diagnosed and the patient was reintubated. After extubation on the following day, airway obstruction was relieved, but slurred speech and impaired swallowing were persistent. In view of this, hypoglossal nerve function should be examined before the second radical neck dissection on the contralateral side.

Amino Acids during Perioperative Period

During anesthesia, thermoregulation is impaired and hypothermia will frequently occur in most patients. Hypothermia affects immunologic activity, bleeding tendency and the recovery from anesthesia. Therefore, it may prolong hospital stay, and increase morbidity, e.g. surgical site infections, cardiac events and multiple organ dysfunctions in trauma. External warming is often used to prevent hypothermia. However, infusion of amino acids is also valuable to prevent hypothermia due to their enhanced thermogenic action under anesthesia. During surgery, amino acids administration would maintain the body homeostasis, and counteract the disadvantageous fasting metabolism. Postoperatively, amino acids may be advantageous for the healing of the surgical wound. Thus, appropriate nutritional management, including glucose, during the perioperative period would prevent catabolism, frequently occurring after surgery. Protocols like ERAS (Enhanced Recovery After Surgery) are proposed for quick recovery after surgery. ERAS protocol recommends preoperative carbohydrate and early enteral nutrition, but does not include infusion of amino acids during the perioperative period. During prolonged surgery, patients clearly need good nutritional support. In this article, we intend to describe the problems of hypothermia briefly, and explain the mechanism of amino acids in hypothermia prevention. In addition, we address some evidences of nutritional management during the perioperative period.

比较丙泊酚和右美托咪啶用于静脉镇静：对中枢和自主神经系统作用的随机交叉研究

我们比较了丙泊（propofol，PROP）和右美托咪啶（dexmedetomidine，DEX）镇静对心理应激状态下的志愿者的自主神经活性和主观感觉的影响。在交叉设计中，25例受试者输注PROP和DEX直至双频指数值达到75-85，对心率、心率变异率、α-唾液淀粉酶（客观指数）、表情焦虑量表（主观指数）进行评估。询问受试者在两种镇静剂中更偏好哪一种。两组中客观指数的改变相似，表情焦虑量表评分仅在PROP组下降，受试者也更偏爱PROP。与DEX相比，丙泊酚镇静能更有效地抑制焦虑。