Search

Background/Objectives: Airway management techniques, including mask ventilation and tracheal intubation, are vital across medical settings. However, these procedures can be challenging, especially when environmental conditions are less than ideal. This study explores how the height of the operating table affects the difficulty of anesthesia techniques involving mask ventilation and tracheal intubation. Methods: Twenty anesthesiologists participated in this study. We assessed the difficulty of procedures such as mask ventilation, Macintosh laryngoscopy, and video laryngoscopy using McGRATH and AWS, on a four-level scale. The operating table's height was adjusted at four points: the operator's umbilicus, the inferior margin of the 12th rib, the xiphoid process, and the nipple. Results: Mask ventilation was easiest at the operating table's height aligned with the inferior margin of the 12th rib. Conversely, direct laryngoscopic exposure was perceived as easier at higher table heights, with nipple height being optimal. The McGRATH laryngoscopy showed consistent difficulty across table heights, whereas the AWS tended to be somewhat more difficult at greater heights. Conclusions: The optimal bed height for video laryngoscopy coincided with that for mask ventilation. Video laryngoscopy offers enhanced flexibility in optimal patient positioning compared to Macintosh laryngoscopy, contributing to its advantages in tracheal intubation procedures. [ABSTRACT FROM AUTHOR]

Background We compared the pharmacokinetics of levobupivacaine when administered intraperitoneally, subcutaneously, and intravenously in an anesthetized rat model, to estimate the toxicity risk of a local anesthetic when absorbed from the peritoneum. Methods Thirty-two rats were anesthetized with sevoflurane. In Experiment 1, we administered 5.0 mg/kg of levobupivacaine intraperitoneally (IP) (n = 7), subcutaneously (SC) (n = 6), or intravenously (IV) (n = 6). In Experiment 2, we administered 2.5 mg/kg of levobupivacaine IP (n = 7) or SC (n = 6). Data are shown as median [range] of Experiment 1. Results In either of experiments, the time to reach maximum plasma concentration of levobupivacaine was shorter in the IP group than in the SC group (IP: 2 [2-5] min; SC: 5 [2-10] min; P = 0.04), and the maximum concentration of levobupivacaine did not differ between the IP and SC groups (IP: 0.45 [0.05-0.67] [micro]g/mL; SC: 0.47 [0.21-0.62] [micro]g/mL; P = 0.90). The area under the curve from time 0 to 120 min after levobupivacaine administration was significantly higher in the SC group than in the IP group in both experiments (IP: 0.29 [0.10-0.54] mg h/L; SC: 0.78 [0.39-0.98] mg h/L; P = 0.04). Conclusion Levobupivacaine is rapidly absorbed following IP administration, but its maximum plasma concentration within 2 h following IP administration is no statistical difference as that following SC administration. On the other hand, when levobupivacaine is given subcutaneously, T.sub.max can exceed 1 h, so we need to be aware of local anesthetic toxicity during this period., Author(s): Hirotsugu Miyoshi [sup.1], Takahiro Kato [sup.1], Ryuji Nakamura [sup.1], Noboru Saeki [sup.1], Yuko Noda [sup.1], Satoshi Kamiya [sup.1], Atsushi Morio [sup.1], Yasuo M. Tsutsumi [sup.1] Author Affiliations: (1) grid.470097.d, [...]

Background: Diabetic neuropathic pain is a known complication of diabetes mellitus (DM) and results from the complex interaction of various factors affecting the nervous system. Yokuansan (YKS) is a versatile traditional Japanese herbal medicine with a wide range of applications, especially in pain management and neurological manifestations. YKS has analgesic properties for nerve damage and is a potential treatment for DM-induced neuropathic pain, especially in patients with diabetic neuropathy. Thus, we examined the anti-allodynic effect of YKS on DM-induced neuropathic pain. Methods: All experiments were performed on 6-week-old male Sprague–Dawley rats. DM and diabetic neuropathy were induced in rats with streptozotocin. Mechanical allodynia was assessed using dynamic plantar esthesiometry. Additionally, we conducted an immunological assessment of microglia cell changes in the spinal cord and an experiment to clarify the involvement of serotonin. Results: Diabetes significantly reduced withdrawal thresholds in rats during the initial two weeks of the experiment, which stabilized thereafter. However, this effect was not investigated in the control group. We assessed, using the dynamic plantar test, the anti-allodynic effects of orally administered YKS (1 g/kg). Daily YKS administration significantly increased the withdrawal threshold in DM animals. Additionally, oral YKS reduced the expression of Ibal-1-positive microglia. To elucidate the mechanism of action of YKS, we explored the involvement of serotonin (5-hydroxytryptamine [5-HT]) receptors in mediating its effects. Intrathecal administration of 5-HT receptor antagonists (WAY-100635, ketanserin, and ondansetron) inhibited the protective effects of YKS. Conclusions: YKS exhibited an anti-allodynic effect, suggesting that YKS may activate 5-HT receptors in the spinal cord, thereby alleviating diabetic neuropathic pain. [ABSTRACT FROM AUTHOR]

Author(s): Yuko Noda [sup.1] , Toshimichi Yasuda [sup.1 ] , Rieko Kanzaki [sup.1] , Hirotsugu Miyoshi [sup.2] , Keiko Mukaida [sup.3] , Satoshi Kamiya [sup.1] , Atsushi Morio [sup.1] , [...]

Background We have noted that patients frequently complain of thoracic or low back pain after undergoing an endovascular aortic repair, which we speculated was caused by the indwelling stent. Methods We investigated the patients who underwent an elective thoracic or abdominal endovascular aortic repair (TEVAR or EVAR) and noted the location of stent, and postoperative pain. The incidence of either thoracic or low back pain at individual vertebra levels was determined, after which we fitted the sigmoidal function to the discrete data to obtain a cut-off line. The study patients were then divided into 2 groups using the cut-off line to compare the incidence of pain. Results We analyzed 96 patients (68 TEVAR, 28 EVAR). The incidence of thoracic pain was significantly higher in TEVAR as compared to EVAR (26.5% vs. 3.6%, P = 0.01), while that of low back pain was significantly higher in EVAR (35.7% vs. 16.2%, P = 0.04). With the cut-off line for thoracic pain set at the 12th thoracic vertebra, the incidence of thoracic pain was significantly higher in patients with the upper end of the stent above the cut-off as compared to at a lower point (26.5% vs. 3.6%, P = 0.01). As for low back pain, the cut-off line was set at the 9th thoracic vertebra, and the incidence of that pain was significantly higher in patients with the lower end of the stent below that line (30.9% vs. 0.0%, P < 0.01). Conclusion Thoracic and low back pain after an endovascular aortic repair procedure were associated with stenting site., Author(s): Hirotsugu Miyoshi [sup.1] [sup.2] , Hiroshi Hamada [sup.1] , Ryuji Nakamura [sup.1] , Takashi Kondo [sup.1] , Toshimichi Yasuda [sup.1] , Noboru Saeki [sup.1] , Masashi Kawamoto [sup.1] Author [...]

Purpose Malignant hyperthermia (MH) is an inherited muscle disorder caused by abnormal elevations of intracellular calcium (Ca.sup.2+) in skeletal muscle. There are several reports of myotoxicity caused by local anesthetics, and the increased intracellular Ca.sup.2+ is considered to be an important cause. However, there is insufficient evidence regarding myotoxicity in MH-susceptible individuals when large doses of local anesthetics are administered. This study investigated the effect of MH predisposition on myotoxicity. Methods Human skeletal muscle samples were obtained from 22 individuals to determine susceptibility to MH, and were evaluated according to whether their Ca.sup.2+-induced Ca.sup.2+ release (CICR) rates were accelerated or not. This study was performed using surplus muscle that remained after the CICR rate test. We calculated the 50% effective concentration (EC.sub.50) values of three local anesthetics, namely lidocaine, levobupivacaine, and ropivacaine using the ratiometric dye Fura-2 AM. Significance was tested using the unpaired t test. Results In the accelerated and unaccelerated groups, respectively, the mean ± SD of the EC.sub.50 values were 1.52 ± 0.72 and 1.75 ± 0.37 mM for lidocaine (p = 0.42), 0.72 ± 0.36 and 0.79 ± 0.46 mM for levobupivacaine (p = 0.68), and 1.21 ± 0.35 and 1.62 ± 0.57 mM for ropivacaine (p = 0.06). These values were similar in individuals with and without MH predisposition. Conclusion The myotoxicity of local anesthetics was equivalent in individuals with and without predisposition to MH., Author(s): Sachiko Otsuki [sup.1] , Toshimichi Yasuda [sup.2] , Keiko Mukaida [sup.3] , Yuko Noda [sup.1] , Rieko Kanzaki [sup.1] , Hirotsugu Miyoshi [sup.1] , Takashi Kondo [sup.1] , Hiroshi [...]

Purpose The aim of this study was to analyze the genetic and functional role of a novel RYR1 variant c.251 C > T (p.Thr84Met) identified in a patient with muscle weakness demonstrating MH susceptibility. Methods DNA testing of family members was conducted for assessment of pathogenicity of the genetic variant. For functional analysis, Ca.sup.2+ measurement using patient-derived myotubes and p.Thr84Met RYR1-transfected human embryonic kidney (HEK)-293 cells was performed to evaluate reactivity to RYR1 activators. The half-maximal effective concentration (EC.sub.50) values of two RYR1 activators, caffeine and 4-chloro-m-cresol (4CmC), were calculated from the acquired dose-response curves. The EC.sub.50 was compared between two groups: for myotubes, the control group and the patient, and for HEK-293 cells, WT and p.Thr84Met. Results Dose-response curves for caffeine and 4CmC were shifted to the left in both myotubes and HEK-293 cells compared to controls. The 50% effective concentration values for caffeine and 4CmC were significantly lower in both myotubes and HEK-293 cells compared to controls (P < 0.001 for all comparisons). Conclusions Our results of functional testing indicated RYR1 hypersensitivity to caffeine and 4CmC. We conclude that the genetic variant was associated with MH susceptibility., Author(s): Takashi Kondo [sup.1] , Toshimichi Yasuda [sup.2] , Keiko Mukaida [sup.3] , Sachiko Otsuki [sup.1] , Rieko Kanzaki [sup.1] , Hirotsugu Miyoshi [sup.1] , Hiroshi Hamada [sup.2] , Ichizo [...]

Advantages of thoracic paravertebral analgesia (TPA) include placement of the catheter closer to the surgical field; however, the catheter can become damaged during the operation. We experienced a case of intraoperative TPA catheter breakage that prompted us to perform an experiment to investigate possible causes. A 50-year-old male underwent a thoracoscopic lower lobectomy under general anesthesia with TPA via an intercostal approach. Following surgery, it was discovered that the catheter had become occluded, as well as cut and fused, so we reopened the incision and removed the residual catheter. From that experience, we performed an experiment to examine electrocautery-induced damage in normal (Portex[TM], Smith's Medical), radiopaque (Perifix SoftTip[TM], BBraun), and reinforced (Perifix FX[TM], BBraun) epidural catheters (n = 8 each). Chicken meat was penetrated by each catheter and then cut by electrocautery. In the normal group, breakage occurred in 8 and occlusion in 6 of the catheters, and in the radiopaque group breakage occurred in 8 and occlusion in 7. In contrast, breakage occurred in only 3 and occlusion in none in the reinforced group, with the 5 without breakage remaining connected only by the spring coil. Furthermore, in 7 of the reinforced catheters, electric arc-induced thermal damage was observed at the tip of the catheter. A TPA catheter for thoracic surgery should be inserted via the median approach, or it should be inserted after surgery to avoid catheter damage during surgery., Author(s): Noboru Saeki [sup.1] , Yuki Sugimoto [sup.1] , Yoko Mori [sup.1] , Takahiro Kato [sup.1] , Hirotsugu Miyoshi [sup.1] , Ryuji Nakamura [sup.1] , Tomomichi Koga [sup.1] Author Affiliations: [...]