Kazunori Koga

Ketamine Suppresses Endotoxin-induced Tumor Necrosis Factor Alpha Production in Mice

BackgroundThe cytokines play important roles in the pathophysiologic alterations associated with sepsis, but there are no reports about the effect of anesthetics on their production. Therefore, the authors examined the effect of ketamine on lipopolysaccharide (LPS)-induced and calcium ionophore A23187-induced tumor necrosis factor alpha (TNF-α) production in thioglycolate (TGC)-elicited peritoneal macrophages (MPs) in ddY mice. MethodsKetamine was added to TGC-elicited MPs at various times after the stimulation with LPS or A23187. After the MPs were stimulated by LPS or A23187 and incubated, TNF-α activities in the supernatant of MPs were determined by an L929 cytotoxic assay. In vivo, the ddY mice were injected intraperitoneally with TGC. Four days later, they were injected subcutaneously with ketamine and then injected intravenously with LPS. Two hours after the LPS challenge, TNF-α activities of the sera were determined. ResultsKetamine suppressed both LPS-induced and A23187-induced TNF-α production in a dose-dependent manner. The simultaneous addition of ketamine to LPS-stimulated and A23187-stimulated MPs resulted in a 50% inhibition of TNF-α production at 20 μg/ml and 12.5 μg/ml, respectively. Ketamine also caused a significant suppression of TNF-α production even when added to the MPs 2 h after the LPS challenge. There was a significant decrease in A23187-induced TNF-α production in TGC-elicited MPs in a calcium-depleted medium when compared with that in a calcium-containing medium. Conversely, LPS-induced TNF-α production did not cause such a result. In addition, ketamine could suppress LPS-induced TNF-α production in TGC-pretreated mice in vivo. ConclusionsKetamine suppresses LPS-induced TNF-α production in both TGC-elicited MPs and TGC-pretreated mice.

The gum elastic bougie eases tracheal intubation while applying cricoid pressure compared to a stylet

PurposeTo compare the ease of tracheal intubation facilitated by the gum elastic bougie or the malleable stylet while applying cricoid pressure.MethodsSixty American Society of Anesthesiologists I–III adult patients undergoing elective surgeries participated in this study. After induction of anesthesia with 2.5 mg·kg−1 propofol and vecuronium 0.1 mg·kg−1, the laryngeal view was assessed without and with cricoid pressure. Patients were allocated randomly into two groups: a gum elastic bougie or stylet group. One of the two devices was used for tracheal intubation while applying cricoid pressure. The duration and ease of tracheal intubation was recorded.Main resultsIn 58 patients, the trachea was intubated at the first attempt. In the stylet group, tracheal intubation was difficult and needed more time, especially when the glottic opening was not visible. In the bougie group, the duration and ease of intubation was not influenced by laryngeal view. In the remaining two patients with Cook’s modified 3b laryngeal view, it was impossible to intubate the trachea with these devices.ConclusionsApplying cricoid pressure worsened laryngeal view. The use of a gum elastic bougie was more effective than the use of a stylet to facilitate intubation.RésuméObjectifComparer l’intubation endotrachéale facilitée par la bougie flexible ou le stylet maniable pendant l’application de la compression cricoïdienne.MéthodeSoixante patients adultes, d’état physique ASA I– III, devant subir une intervention chirurgicale réglée ont participé à l’étude. Après l’induction de l’anesthésie avec 2,5 mg·kg−1 de propofol et 0,1 mg·kg−1 de vécuronium, la visualisation du larynx a été évaluée avec et sans compression cricoïdienne. Les patients ont été répartis au hasard en deux groupes pour l’intubation endotrachéale avec la bougie flexible ou le stylet pendant l’application de la compression cricoïdienne. La durée et la facilité de l’intubation ont été notées.Constatations principalesChez 58 patients, l’intubation a été réussie au premier essai. Dans le groupe avec stylet, l’intubation a été difficile et a exigé plus de temps, surtout quand l’ouverture glottique n’était pas visible. Dans le groupe avec bougie, la duré et la facilité de l’intubation n’ont pas été influencées par la visualisation du larynx. Chez les deux patients restants qui présentaient une vue laryngée de classe 3b modifiée de Cook, il a été impossible de réaliser l’intubation avec l’un ou l’autre instrument.ConclusionL’application de la compression cricoïdienne a nui à la visualisation du larynx. La bougie flexible a été plus efficace que le stylet pour faciliter l’intubation.

A Comparison of Two Tracheal Intubation Techniques with Trachlight™ and Fastrach™ in Patients with Cervical Spine Disorders

Optimal airway management strategies in patients with an unstable cervical spine remain controversial. A newly designed lightwand device (Trachlight™) or an intubating laryngeal mask (Fastrach™) may avoid hyperextension of the neck. However, there are few objective data that guide us in selecting the appropriate devices. We conducted a prospective randomized study in 148 patients who received general anesthesia for whom the operations were related to the clinical and/or radiographic evidence of cervical abnormality. Trachlight™ or Fastrach™ was used for tracheal intubation with the head and neck held in a neutral position. In the Trachlight™ group, intubation was successful at the first attempt in 67 of 74 (90.5%) cases and at the second attempt in 5 (6.8%) cases. In contrast, in the Fastrach™ group, 54 of 74 (73.0%) patients were intubated within our protocol. The mean time for successful tracheal intubation at the first attempt was significantly shorter in the Trachlight™ group than in the Fastrach™ group. The Trachlight™ may be more advantageous for orotracheal intubation in patients with cervical spine disorders than the Fastrach™ with respect to reliability, rapidity, and safety.

Comparison of no Airway device, the Guedel-type Airway and the Cuffed oropharyngeal airway with mask ventilation during manual in-line stabilization

STUDY OBJECTIVE To compare two different types of oropharyngeal airway: the Guedel-type oral airway and the Cuffed Oropharyngeal Airway (COPA), with respect to the effectiveness of positive-pressure ventilation (PPV) through a face mask in patients with in-line stabilization of the head and neck. DESIGN Prospective, randomized, crossover study. SETTING University hospital. PATIENTS 30 ASA physical status I and II patients undergoing elective surgery. INTERVENTIONS General anesthesia was induced with propofol and muscle relaxation was produced with vecuronium. In a random sequence, no airway device, the Guedel-type airway, and the COPA were used in each patient while applying a face mask and lifting the jaw forward. MEASUREMENTS AND MAIN RESULTS Tidal volumes were measured during PPV in each option. The position of the distal tip of each airway was assessed using a fiberscope, and the resulting views were graded and compared. When the Guedel-type airway was used, tidal volumes (V(T)s; means +/- SD) were significantly greater (12.3 +/- 4.5 mL/kg) than those with no airway device (8.5 +/- 4.5 mL/kg) (p < 0.001). When the COPA was used, V(T)s (14.6 +/- 4.4 mL/kg) were significantly greater than those with the Guedel-type airway (p < 0.05). The grade of the fiberscopic view through the distal tip was significantly better with the COPA than with the Guedel-type airway (p < 0.05). CONCLUSIONS Although clinical differences often appear trivial, the COPA is more effective on mask ventilation than the Guedel-type airway when used in patients with manual in-line stabilization.

Role of nitric oxide during carrageenan-sensitized endotoxin shock in mice

We have previously clarified that sensitization with a sulfated polygalactose, carrageenan (CAR), enhances endotoxin-induced tumor necrosis factor (TNF) production and lethality in mice. The present study was performed to examine the role of nitric oxide (NO) in CAR-sensitized septic mice with two different types of NO synthase (NOS) inhibitors, a non-selective inhibitor to NOS subtypes, N omega-nitro-L-arginine methyl ester (L-NAME), and a selective inhibitor to inducible NOS, aminoguanidine. Seven or eight-week-old male ddY mice were given 5 mg of CAR intraperitoneally as a primer. Then, 5 micrograms of lipopolysaccharide (LPS) was injected into the tail vein 16 hours later the pretreatment. Marked synthesis of NO was induced in CAR-sensitized mice, as indicated by the high plasma levels of the stable endproducts, NO2-/NO3- peaking at 12 hr after the LPS challenge. The peak values at 12 hr after the LPS challenge were dependent on the dose of CAR with 1 to 5 mg, although the injection with 10 mg of CAR was adversely inhibited NO production compared with 5 mg of CAR. The LPS challenge was followed by either L-NAME (0.25, 0.5 or 1 mg) or aminoguanidine (1, 2 or 4 mg) in the septic mice sensitized with 5 mg of CAR. L-NAME reduced the plasma NO2-/NO3- level in a dose-dependent fashion, although it augmented liver injury, as measured by plasma levels of ornithine carbamyltransferase (OCT) and the LPS-induced lethality in a dose-dependent fashion. In contrast, aminoguanidine did not significantly deteriorate either liver injury or lethality in spite of the decrease of NO endproducts in a similar fashion to L-NAME. These findings suggest that the inhibition of constitutive NOS is detrimental and augments LPS-induced liver injury and subsequent lethality.

Effects of fentanyl on emergence characteristics from anesthesia in adult cervical spine surgery: a comparison of fentanyl-based and sevoflurane-based anesthesia.

PurposeTo evaluate the effects of different anesthesia regimens on bucking, awareness, and pain during the emergence from anesthesia, which may affect neck stabilization and neurological assessment immediately after cervical spine surgery.MethodsPatients scheduled to undergo cervical spine surgery were assigned randomly into one of three groups: maintenance of anesthesia with fentanyl and propofol TCI (group FP, n = 25); maintenance with fentanyl and supplementation with less than 1% sevoflurane (group Fs, n = 25); and maintenance solely with sevoflurane (group S, n = 25). The severity of bucking, extent of awareness during neurological examination, and perception of pain during the emergence phase were assessed using predetermined scoring scales by a nurse blinded to the method of anesthesia.ResultsThe bucking score and pain score were significantly better in group FP and group Fs than in the group S, whereas there was no significant difference between the data of group FP and group Fs.ConclusionThe quality of emergence from anesthesia in patients with cervical spine surgery is improved with fentanyl-based anesthesia, but there is no difference between the use of propofol TCI and less than 1% sevoflurane as a concomitant sedative agent with fentanyl.

Use of the Coopdech Bronchial Blocker™ as a tracheal tube introducer in a patient with difficult laryngoscopy

To the Editor: Difficult airways in surgical patients who require onelung ventilation have long been a challenge for anesthesiologists. Placement of devices for one-lung ventilation is more complicated and difficult than that of normal tracheal tubes [1]. We suggest a simple alternative method to facilitate placement of devices for one-lung ventilation in the case of difficult laryngoscopies. The Coopdech Bronchial Blocker (Daiken Medical, Osaka, Japan) has been clinically introduced to perform one-lung ventilations with a single lumen tracheal tube [2]. Its shape resembles that of the Eschmann tracheal tube introducer. The Parker FlexTip tube (Parker Medical, CO, USA), which has a flexible tip positioned towards the center of its distal lumen, has been reported to be easy to pass over a guide into the trachea [3]. We have successfully used a Coopdech Bronchial Blocker as an applicator for a Parker Flex-Tip tracheal tube for successful intubation and one-lung ventilation in patients not only with normal laryngoscopic views but also in cases when laryngoscopy proved difficult. A 64-year old male was scheduled for left upper lobectomy of the lung. He had no limitation in head extension. His Mallampati score was class 2 and the thyro-mental distance was 6 cm. Anesthesia was induced with propofol and vecuronium was given to facilitate intubation. Mask ventilation was easy. The laryngoscopic view with a Macintosh blade was Cormack–Lehane grade 3. We ventilated the lungs again with 100% oxygen before the second intubation attempt. The Coopdech Bronchial Blocker was inserted through the Parker Flex-Tip tube beforehand (Fig. 1). We performed the laryngoscopy again, obtaining the best possible laryngeal view. However, despite applying external pressure only the epiglottis was visible. The Coopdech Bronchial Blocker was inserted and the marking point 10 cm from the tip reached the edge of the epiglottis. Then the Parker Flex-Tip tube was slid over the blocker and advanced into the trachea. The laryngoscope was withdrawn and the cuff was inflated. Correct positioning of the Parker Flex-Tip tube was verified by auscultation and fiberscopic examination. One-lung ventilation was performed successfully and a satisfactory operative field was achieved. Left upper lobectomy was completed without complication. We suggest use of the Coopdech Bronchial Blocker with the Parker Flex-Tip tracheal tube as a simple alternative means of intubation and one-lung ventilation in a patient with difficult laryngoscopy. Although several newer devices have been developed to aid difficult intubation, they are not readily available in all operating theaters and as such direct laryngoscopy is still widely performed. The advantage of this method is that no other special devices are necessary. However, care must be taken not to injure the vocal cords, trachea, and bronchus, because the material of the Coopdech Bronchial Blocker is harder than that of the Eschmann tracheal tube introducer and the blocker is advanced blindly when the laryngoscopic view is poor. M. Ozaki (&) T. Sata Department of Anesthesiology, School of Medicine, University of Occupational and Environmental Health, 1-1, Iseigaoka, Yahatanishi-ku, Kitakyushu 807-8555, Japan e-mail: m-ozaki@med.uoeh-u.ac.jp

Anesthetic Management Using Echocardiography for Surgery of Lower Extremity in a Patient with Ebstein's Malformation

To the Editor: Ebstein’s malformation is rare congenital heart disease with the downward displacement of the tricuspid valve into the right ventricle. The hazards occurs tachydysrhythmias and hypoxemia owing to the rightto-left intracardiac shunt. We report epidural anesthesia with evaluation of echocardiography during anesthesia in a patient with Ebstein’s malformation. A 58-yr-old woman underwent emergent repair for left foot joint fracture. The Ebstein’s malformation had been found at 42 yr of age, but no right-left shunt was found at that time. Echocardiography revealed downward displacement of the tricuspid valve but no right-to-left shunts. We estimated cardiac function using echocardiography from the start of anesthesia. After spinal anesthesia was induced with 0.5% bupivacaine (10 mg), the epidural catheter was introduced to the epidural space via the L4-5 space. A total dose of 11 mL of mepivacaine 1% produced analgesia from S5 to T11. Arterial blood pressure and heart rate did not change with anesthesia and Spo2 also remained at 100%. The right ventricle diastolic diameter before and after anesthesia was 2.9 cm and 3.0 cm, respectively (Figures 1 and 2). During surgery, we continued observing the right ventricle diastolic diameter to avoid excessive administration of IV fluids. Total fluid was 700 mL. During and after anesthesia, her vital signs did not change to any clinical significant degree. Hazards during anesthesia include development of cardiac tachydysrhythmias and hypoxemia as the result of increases in the magnitude of the right-to-left intracardiac shunts. Several anesthetic managements in patients with Ebstein’s malformation have been described (1–4). General anesthesia has the advantage that hypotension tends to be avoided, but arrhythmia and tachycardia may occur after intubation and extubation of the trachea. In contrast, Linter and Clarke (2) showed the successful use of a two-catheter technique for elective Cesarean delivery with extradural analgesia. Epidural or spinal anesthesia may be appropriate in non-severe patients, but excessive administration of fluid should be avoided because it may increase right arterial pressure sufficiently to cause an increased right-to-left shunt and hypoxemia. In this anesthesia, we evaluated cardiac preload and function using echocardiography. Although central venous pressure monitoring or the insertion of a pulmonary artery catheter may be useful to evaluate cardiac preload, these measures may be technically difficult in Ebstein’s anomaly and lead to complications such as tachyarrhythmias or paradoxical emboli. Transesophageal echocardiography may be also useful, but it would be difficult to monitor in our case for an extended period because the patient was awake during surgery. Echocardiography is and noninvasive and can be used frequently. It provides much information about changes of the cardiovascular system, especially for this patient with Ebstein’s malformation even during anesthesia. In conclusion, epidural or spinal anesthesia may be appropriate in nonsevere patients and echocardiography should be useful monitoring during anesthesia for patients with Ebstein’s malformation.