Biomedical subjects
Publications and source records attributed to Koh Shingu.
Contralateral pneumothorax is potentially lethal in patients who have undergone pneumonectomy. There are few reports about the diagnosis and treatment of this situation. This is a report of our experience with selective lobar ventilation of the middle and lower lobes using a guidewire and a bronchial blocker in the right upper bronchus of a patient who had previously undergone left pneumonectomy.
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Dopamine release in the nucleus accumbens (NAC) plays a crucial role in the action of various psychotropic and addictive drugs, such as antagonists of the N-methyl-D-aspartate subtype of the glutamate. Although both nitrous oxide and xenon are N-methyl-D-aspartate receptor antagonists, they differ in their potential for producing neuropsychological toxicity; therefore, we decided to examine their effects on both spontaneous and ketamine-induced extracellular dopamine levels in the NAC. A microdialysis probe was implanted into the NAC in each of 35 rats, which were randomly assigned to one of six groups: exposure to 40% O2, exposure to 60% nitrous oxide (0.27 MAC), exposure to 43% xenon (0.27 MAC) for 60 min, and three groups exposed to either 40% O2, 60% nitrous oxide, or 43% xenon for 70 min and 80 mg/kg ketamine was given i.p. 10 min after the initiation of gas exposure. Perfusate samples were collected every 20 min, and the dopamine levels were measured using a high-performance liquid chromatography system. Nitrous oxide, but not xenon, significantly increased the dopamine level. Ketamine significantly increased the dopamine level, and this was significantly inhibited by xenon, but not by nitrous oxide. These data suggest that the difference in neuropsychological activity between nitrous oxide and xenon is partly due to their differential effects on the mesolimbic dopamine system.
A 19-year-old man with cervical spondylosis (C4-C6) was scheduled for an anterior spine surgery. Anesthesia was induced with propofol and fentanyl, and nasotracheal intubation was performed without difficulty after vecuronium administration. Anesthesia was maintained with sevoflurane and nitrous oxide in oxygen supplemented with fentanyl. No complications were observed during the operation. After surgery, the patient's head and neck were stabilized by a halo-vest, and we attempted to minimize stress responses associated with tracheal extubation. While the patient was still deeply anesthetized, and the nasotracheal tube was in place, a laryngeal mask airway (LMA) was placed without difficulty. After confirming correct position of the LMA, the nasotracheal tube was removed without body movement or coughing. Removal of the LMA was safely performed after recovery of the patient's respiration and consciousness. We believe that the laryngeal mask airway is useful during emergence from anesthesia in the patient whose trachea is intubated nasally.
The need for one-lung ventilation has been increasing even in pediatric patients. However, the trachea is so narrow in pediatric patients that ordinary double-lumen tubes can not be used and there have been many reports on devices or measures to block one lung. We report our experience with a female infant weighing 2 kg who had severe chronic lung disease under mechanical ventilation, and underwent left lung lower lobectomy with one-lung ventilation technique. We chose a balloon wedge pressure catheter to block the left main bronchus, because it has a central lumen through which a guide wire can be passed and sucking is available. The infant was in need of continuous ventilation and the catheter was too soft to be inserted directly. We first inserted an 18G catheter of a needle-catheter assemble outside the tracheal tube through which a guide wire was inserted into the left main bronchus with the aid of direct vision of a 2-mm fiberoptic bronchoscope through the tracheal tube, and then inserted the balloon wedge pressure catheter placing it in an appropriate position. One-lung ventilation was successfully achieved and the operative and postoperative course was uneventful.
Selective immobilisation of the lobes of the lungs with a bronchial blocker is sometimes a challenge for anesthesiologists. A pneumonorrhaphy was planned in a patient who had had undergone left pneumectomy, and selective immobilisation of the right upper lobe was requested. The initial attempt to place the cuff of a bronchial blocker was unsuccessful. We inserted a urethral guide-wire through fiberoptic bronchoscope and positioned the tip at the orifice of the right upper bronchus. We then threaded the bronchial blocker through the guidewire and placed the cuff at the right upper bronchus. The right upper lobe was successfully collapsed, which greatly facilitated the surgical procedure. The method is easy, fast, and safe and should be considered when difficulty in placement of the bronchial blocker is encountered.
BACKGROUND: Efficacy and safety of Org 9426 were compared with those of vecuronium bromide in Japanese patients. METHODS: We studied 88 Japanese patients undergoing surgery requiring general anesthesia. Patients were allocated randomly to receive intubation dose of 0.6 mg x kg(-1), 0.9 mg x kg(-1) of Org 9426 or 0.1mg x kg(-1) of vecuronium. Following an intubation dose, patients received maintenance doses of 0.1, 0.15 or 0.2 mg x kg(-1) of Org 9426 or 0.025 mg x kg(-1) of vecuronium. The neuromuscular block was monitored with acceleromyography using TOF stimuli. Sevoflurane was administered to all treatment groups after intubation. RESULTS: The onset times of the 0.6 and 0.9 mg x kg(-1) of Org 9426 groups were 84.6 and 77.1 sec respectively, which showed statistical difference between the onset time of 0.1 mg x kg(-1) of vecuronium, 125.7 sec. The intubation condition was similar among three treatment groups. The clinical durations of 0.6 and 0.9 mg x kg(-1) of Org 9426 and 0.1 mg x kg(-1) of vecuronium were 53.4, 73.4 and 59.9 min, respectively. Clinical duration and spontaneous recovery time of maintenance dose of 0.15 mg x kg(-1) of Org 9426 were similar to those of 0.025 mg x kg(-1) of vecuronium. CONCLUSIONS: Org 9426 showed more rapid onset time than that of vecuronium and similar clinical duration and recovery times to those of vecuronium in Japanese patients.
BACKGROUND: Spinal anesthesia using a local anesthetic with fentanyl has been reported to induce sedation. We previously reported that the bispectral index (BIS) value was significantly decreased by spinal anesthesia using only bupivacaine and fetanyl after cesarean delivery. In the present study, we studied the effect of different fentanyl administration routes on BIS values during spinal anesthesia for cesarean section. METHODS: Forty-six women scheduled for cesarean section were allocated into five-groups according to the route of fentanyl administration and amount of local anesthetic: intrathecal 0.5% isobaric bupivacaine 2.5 ml plus fentanyl 20 microg (n = 11), intrathecal 0.5% isobaric bupivacaine 2.5 ml plus intravenous fentanyl 100 microg (n = 12), intrathecal 0.5% isobaric bupivacaine 2.5 ml plus epidural fentanyl 100 microg (n = 8), intrathecal 0.5% isobaric bupivacaine 2.5 ml (n = 8), and intrathecal 0.5% isobaric bupivacaine 3.0 ml (n = 7). BIS values were recorded during anesthesia. RESULTS: BIS values in intrathecal fentanyl group were lower than those of other groups (P = 0.03). The cumulative duration of BIS values 80 and below 80 was longer in the intrathecal fentanyl group than those of other groups (P = 0.004). CONCLUSION: The BIS value was significantly decreased only by intrathecal fentanyl for cesarean section.
The second window of preconditioning (SWOP) induced by inhalation of volatile anesthetics has been documented in the rat heart and is triggered by nitric oxide synthase (NOS), but involvement of NOS in the mediator phase of isoflurane-induced SWOP has not been demonstrated. We tested the hypothesis that isoflurane-induced SWOP is mediated through upregulation of inducible NOS (iNOS). Rats inhaled 0.75 minimum alveolar concentration (MAC) isoflurane, 1.5 MAC isoflurane, or O2 for 2 h. After 24, 48, 72, and 96 h, the isolated heart was perfused with buffer and subjected to 30 min of ischemia followed by 2 h of reperfusion. Inhalation of 0.75 and 1.5 MAC isoflurane significantly limited infarct size after ischemia-reperfusion 24-72 h after isoflurane inhalation. The maximum effect was obtained 48 h after inhalation of 1.5 MAC isoflurane. Postischemic left ventricular function was improved only 48 h after inhalation of 1.5 MAC isoflurane. iNOS expression and activity in the heart were increased 24-72 h after inhalation of 1.5 MAC isoflurane; this increase was less pronounced after inhalation of 0.75 MAC isoflurane. A selective iNOS inhibitor, 1400W (10 microM), abolished iNOS activation and cardioprotection induced 48 h after inhalation of 1.5 MAC isoflurane. These results suggest that isoflurane inhalation induces SWOP after 24-72 h through overexpression and activation of iNOS in the rat heart.
PURPOSE: Hypoxia (reduced oxygen availability) induces a series of adaptive physiological responses. At the cellular level, the adaptation includes a switch of energy metabolism from oxidative phosphorylation to anaerobic glycolysis, increased glucose uptake, and the expression of stress proteins related to cell survival. One of the most important transcription factors that activate the expression of oxygen-regulated genes is hypoxia-inducible factor 1 (HIF-1). We previously reported that halothane inhibits the hypoxia-induced HIF-1 activation. In this study, we investigated the effect of local anesthetics on HIF-1 activation and its downstream gene expression. METHODS: The established cell line Hep3B and SK-N-MC cells were exposed to 1% O2 with or without treatment by either lidocaine or bupivacaine. Expression of subunits of HIF-1, HIF-1alpha, and HIF-1beta was examined by Western blot using specific antibodies. Expression of mRNA of HIF-1 and the HIF-1-dependent genes was investigated by RT-PCR and reporter assay. RESULTS: Neither of the local anesthetics tested affected the accumulation of HIF-1alpha induced by hypoxia, nor did they affect NOC18-induced HIF-1alpha accumulation. Moreover, they had no effects on HIF-1-mediated hypoxia-induced gene expression. CONCLUSION: The local anesthetics lidocaine and bupivacaine did not affect the HIF-1-dependent cellular hypoxia-induced gene responses.
Romano-Ward (R-W) syndrome is an autosomal dominant hereditary disorder and is characterized by a prolonged QT interval on the electrocardiogram (ECG), syncope, and sudden death. We report here a case of cesarian section in a patient with R-W syndrome whose QT prolongation was successfully managed with landiolol, a selective beta1 receptor blocker. A 25-year-old woman with R-W syndrome was scheduled for cesarean section. In the operating room, the patient's ECG showed tachycardia (102 beats x min(-1)) and marked QT prolongation (QTc = 0.56 s). After spinal anesthesia, the patient's heart rate (HR) increased to 130 beats/min accompanied by a slight decrease in arterial blood pressure to 97/57 mmHg and the QTc was prolonged to 0.57 s. Landiolol was continuously infused at a rate of 0.04 mg.kg(-1) x min(-1) and the HR gradually decreased to 80-90 beats x min(-1) accompanied by the normalization of QTc to 0.48 s. We thought that the use of landiolol was more rational and was preferable to a nonselective beta receptor blocker for a term-pregnant woman because blockade of the beta2 receptor might cause uterine contraction. After the use of landiolol, intraoperative and postoperative courses in both the patient and the baby were uneventful.
Hypoxia induces a series of adaptive physiological responses including gene inductions. Hypoxia-inducible factor 1 (HIF-1) is a master transcription factor that regulates hypoxia-induced gene expression to maintain homeostasis in the living body. Opioids are potent analgesic agents that are widely used in clinical practice. Therefore, we investigated the effect of opioids on HIF-1 activity. SH-SY5Y human neuronal cells, which express opioid receptors intrinsically, were cultured under 1% or 20% O2 conditions with or without treatment by DAGO, DPDPE, or U-50488, which are the selective agonists of mu-, delta-, and kappa-opioid receptors, respectively. Expression of subunits of HIF-1, HIF-1alpha, and HIF-1beta were examined by Western blot using specific antibodies. Expression of the HIF-1-dependent gene were investigated by reporter assay. None of the selective agonists of opioid receptors tested affected HIF-1 activation by hypoxia. Therefore, it is suggested that opioid receptor-mediated signals do not affect HIF-1-dependent cellular hypoxia-induced gene responses.
Optimal safety for a donor is an essential condition for living-related liver transplantation (LRLT). Severe pulmonary embolism may be a rare complication for the donors, but it is potentially fatal. Various risk factors and prophylactic methods for thromboembolic complications have been described. We report here a case of severe pulmonary embolism in a living-related liver transplantation donor who underwent right liver lobectomy, although the patient had no apparent risk factor for thromboembolism except for slight obesity (body mass index = 27). In addition, the donor received prophylactic use of graduated compression stockings and intermittent pneumatic compression by use of a special device from the start of anesthesia until the patient was able to ambulate. Fortunately, the patient was successfully treated with urokinase and heparin infusion followed by warfarin administration.
Dexmedetomidine, a selective alpha2 adrenergic receptor agonist, is a drug often used for sedation. Despite the high prevalence of sedating patients with tumors in intensive care settings, little is known about the effect of sedative drugs on tumor growth. We studied the effect of dexmedetomidine on antitumor immunity in mice. Subhypnotic doses of dexmedetomidine decreased interleukin (IL)-12 production from thioglycollate-induced macrophages. The treatment also decreased the ratio of the helper T lymphocytes subsets, Th1 to Th2 (Th1/Th2), in the spleen. Following subcutaneous inoculation of EL4 T-cell lymphoma cells, dexmedetomidine further decreased the splenic Th1/Th2 ratio and activity of EL4-specific cytotoxic T lymphocytes (CTLs). Finally, treatment with dexmedetomidine accelerated EL4 growth in mice. These data show that treatment of mice with subhypnotic doses of dexmedetomidine down-regulates antitumor immunity, possibly through the decreased production of IL-12 from antigen presenting cells, resulting in a Th2 shift and decreased CTL activity against EL4 in mice.
Cor triatriatum is a rare congenital cardiac anomaly, in which left ventricular filling is impeded by obstructive membrane in the left atrium. We administered spinal anesthesia for cesarean section in a patient with cor triatriatum (type III A1) with congestive heart failure. We optimized hemodynamics with the aid of pulmonary artery cathter. In general, cor triatriatum involves similar hemodynamic profiles to mitral stenosis and thus tachycardia should be avoided during anesthesia. However, in our patient, increasing the heart rate to 80-90 beats x min(-1) was beneficial in maintaining adequate systemic blood pressure and cardiac output. Spinal anesthesia could be a method of choice for cesarean section in a patient with cor triatriatum when adequate hemodynamic monitoring is available.
Neonates with 18-trisomy syndrome have various anomalies including cardiac and facial anomalies. Active treatments for them have not been recommended due to a low survival over one year which is less than 10%. However, the survival over one year in our institute between 1985 and 2003 is higher at 22%, and we had a patient with survival of over 5 years. We report a case of anesthetic management in a male 18-trisomy neonate who received a radical repair of umbilical hernia immediately after his birth. Tracheal intubation was difficult due to small airway and facial anomalies; cleft clip, cleft palate, and macrognathia. Conventional ventilation was ineffective for elimination of carbon dioxide and oxygenation due to pulmonary hypoplasia and intra- and extra-cardiac shunts. A high frequency ventilation improved elimination of carbon dioxide and oxygenation.
We anesthesiologists sometimes encounter a situation where we difficulty detaching an L connector from an endotracheal tube. However, to our knowledge, there is no paper wich describes complete inability of detaching the connector from the tube. A 33-year-old female patient was scheduled for jaw joint arthroplasty and manipulation of synarthrophysis after the previous intermaxillary fixation. After midazolam and fentanyl administration, the trachea was intubated with a reinforced endotracheal tube (Mallinckrodt Inc., St. Louis, USA) through the right nostril with the aid of a bronchofiberscope. When we tried to move the anesthesia machine, we could not detach the L connector from the endotracheal tube by any means. Furthermore, because a slip-joint is glued to a reinforced endotracheal tube, it was impossible to separate them. The patient had locklaw, and therefore to avoid reintubation, we scraped off the surface of the L connector, and the connector was successfully detached. Although slip-joints of tracheal tubes and L connectors are standardized with JIS and ISO, their connection is not necessarity good due to the difference of makers and/or a tolerance of products. We think that Tracheostomy Wedge (Portex Inc., New Hampshire, USA) is useful for detaching the cconnection.