Biomedical subjects

Tomoki Nishiyama

Publications and source records attributed to Tomoki Nishiyama.

At least 37 records · Page 2Linked to original sources

PubMed2005

Inhibitory effects of intravenous anesthetics on mast cell function.

UNLABELLED: Mast cells play a protective role in the inflammation and auto-tissue injury. The impairment of mast cell function may influence defense against infection. We investigated the effect of four IV anesthetics (thiopental, midazolam, ketamine, and propofol) on the chemotaxis and exocytosis of mast cells. Canine mast cell chemotaxis was measured by the Boyden's blindwell chamber technique using 100 microg/mL of substance P as a stimulator. We measured mast cell exocytosis by measuring released histamine from mast cells using substance P or gamma-monomeric IgG-mediated crosslinking as a stimulator. Thiopental, midazolam, and propofol exerted a dose-dependent inhibitory effect on mast cell chemotaxis. Ketamine, midazolam, and propofol had a dose-dependent inhibitory effect on mast cell exocytosis. In conclusion, midazolam and propofol inhibited both chemotaxis and exocytosis of mast cells, while thiopental only inhibited chemotaxis, and ketamine only inhibited exocytosis. IMPLICATIONS: Mast cells play an important role in the antibacterial host-defense mechanism. Thiopental, midazolam, and propofol exerted a dose-dependent inhibitory effect on mast cell chemotaxis. Ketamine, midazolam, and propofol had a dose-dependent inhibitory effect on mast cell exocytosis. The impairment of mast cell function by IV anesthetics may influence the defense against infection.

Anesthetics, Intravenous↗

PubMed2005

[A case of thoraco-amniotic shunt for congenital cystic adenomatoid malformation].

Congenital cystic adenomatoid malformation (CCAM) is a congenital pulmonary anomaly, which may lead to fetal hydrops, pulmonary hypoplasia, and fetal or neonatal death. Recently, diagnosis and surgery for fetus have been improved. We experienced a case of CCAM, classified in Stocker class I, with a single cyst of about 5 cm in diameter. A 32 year-old pregnant woman had a fetus diagnosed as CCAM at 25 th gestational week. The thoraco-amniotic shunt placement using a modified double pig tail catheter was performed at 27 th gestational week under general anesthesia with 1% isoflurane in oxygen 2 l x min(-1) and nitrous oxide 4 l x min(-1), and 100 microg of fentanyl. Fetal movement was suppressed during surgery. This fetal therapy was effective and the cyst disappeared after surgery. The baby was delivered with caesarian section under spinal anesthesia with 0.5% bupivacaine 2.5 ml. On the next day, right lung lobectomy was accomplished under general anesthesia with fentanyl 0.2 mg and pancuronium 6.0 mg. Anesthesia with isoflurane, nitrous oxide, and fentanyl was useful for the fetal surgery of thoraco-amniotic shunt placement. Consequently, caesarian section and lung lobectomy were completed successfully.

Adult↗

PubMed2005

[Does common cold increase perioperative respiratory complications in adults?].

BACKGROUND: We investigated whether perioperative respiratory complications increase in adults with common cold symptom. METHODS: Thirty patients who had had a common cold (nasal congestion, rhinorrhea, sneeze, cough, sputa, or fever) in two weeks before general anesthesia and other 30 patients without any symptoms were enrolled in this study. All the patients were anesthetized with intravenous or inhalation anesthetics and were intubated. The incidences of bronchospasm, laryngospasm, dry or moist rale on lung field, increase in sputa or cough, and fever were checked during and for 5 days after, surgery. RESULTS: More patients with common cold showed dry or moist rale, increase in sputa or cough, and fever than those without common cold. Even though these were not statistically significant, three severe complications, respiratory as well as cardiac arrest, pneumonia, and prolonged intubation due to increased sputa, were observed. CONCLUSIONS: General anesthesia with oro-tracheal intubation should be postponed at least two weeks after common cold in adults.

Adult↗

PubMed2005

[General anesthesia for a patient with Noonan's syndrome and long-term antidepressant therapy].

Noonan's syndrome is associated with cardiovascular, spinal and airway abnormalities. We experienced general anesthesia for a patient with Noonan's syndrome and long-term antidepressant therapy. A 42-year-old man was scheduled for radical operation for ventral hernia. He had been diagnosed as Noonan's syndrome by his facial and spinal abnormalities. He was intubated under bronchofiberscopy for his previous general anesthesia. He had received amitriptyline 50 mg daily for ten years. Anesthesia was induced with midazolam 3 mg, fentanyl 50 microg, droperidol 1.25 mg. He was intubated under bronchofiberscopy after topical lidocaine 400 mg application. Then thiopental 125 mg and sevoflurane 0.4% was administered. Blood pressure decreased after intubation to 70/40 mmHg, which was resistant to ephedrine 10 mg. After starting surgery, blood pressure increased to 100/70 mmHg and was stable until the end of surgery. This patient presented a problem of difficult intubation as Noonan's syndrome and had a history of a long-term use of antidepressant, which might induce sympathomimetic resistant hypotension.

Adult↗

PubMed2005

[General anesthesia for a patient with asymptomatic sick sinus syndrome].

A 67-year-old man with glioblastoma was scheduled for craniotomy. Before anesthesia induction, asymptomatic bradycardia (40 beats x min(-1)) occurred, and was resistant to atropine 0.4 mg. The surgery was postponed. He was diagnosed as sick sinus syndrome (sinus arrest). He received implantation of a temporary cardiac pacemaker on the day before the rescheduled surgery. Anesthesia was induced with thiopental 400 mg, fentanyl 200 microg, vecuronium 10 mg and isoflurane 5%, and maintained with isoflurane 1-2% in oxygen 3 l x min(-1) and air 3 l x min(-1). Pacing mode was set to fixed rate asynchronous pacing in the ventricle with a rate of 50 beats x min(-1) after anesthesia induction. Surgery was completed in 8 hours and 45 minutes without any complications. The pacing wire was removed the next day. For patients with sick sinus syndrome, implantation of the pacemaker is indicated in case of bradycardia-tachycardia syndrome or with any clinical symptoms. However, a pacemaker should be implanted before general anesthesia even in a patient with no clinical symptoms because of cardiovascular instability induced by anesthesia.

Aged↗

PubMed2005

[General anesthesia for a patient with pulmonary hypertension, bronchial asthma and obesity].

The management of the patient with pulmonary hypertension is a challenge for the anesthesiologists because the risk of right-sided heart failure is markedly increased. We experienced a case of general anesthesia for a patient with pulmonary hypertension (mean pulmonary arterial pressure 39 mmHg), bronchial asthma and obesity. A 31-year-old woman was scheduled for arytenoid rotation for left recurrent nerve palsy. We applied routine monitors (noninvasive blood-pressure, five-lead electrocardiogram, pulse oximeter), and direct blood pressure monitoring through the radial artery. Anesthesia was induced with midazolam 4 mg, fentanyl 100 microg and sevoflurane 5%, and maintained with sevoflurane (1-2%) and nitrous oxide in oxygen. Surgery was completed in 100 minutes without any complications. We could successfully perform general anesthesia in a patient complicated by pulmonary hypertension, bronchial asthma and obesity, without invasive right-sided heart catheterization.

Adult↗

PubMed2005

[Anesthesia for argon plasma coagulation therapy through the tracheostomy site].

We experienced a case of argon plasma coagulation (APC) therapy for bronchial obstruction. A 54-year-old man was scheduled for APC therapy for bronchial obstruction using bronchoscope via a tracheostoma. The patient had received left upper lobectomy four years before and laryngectomy and tracheotomy two years before. Anesthesia was induced with droperidol 2.5 mg, and gradual administration of fentanyl (total 125 microg) and midazolam (total 1 mg). Surgery was completed in 15 minutes under spontaneous breathing of air. In APC therapy, we cannot administer oxygen for fear of argon-ignited intratracheal combustion. Using small doses of droperidol, fentanyl, and midazolam, we could successfully anesthetize a patient for APC therapy through the tracheostomy site under spontaneous respiration with air.

Anesthesia↗

PubMed2005

[General anesthesia for diaphragmatic herniorrhaphy in a patient with myasthenia gravis and severe gibbus].

We experienced a case of diaphragmatic herniorrhaphy complicated with myasthenia gravis (MG) and gibbus. A 66-year-old woman was scheduled for diaphragmatic herniorrhaphy. She had a 10-year history of MG graded Osserman classification IIA. She had received prednisolone and pyridostigmine. After epidural catheter insertion into T 6-7 interspinal space, anesthesia was induced with sevoflurane 5% and maintained with sevoflurane 1%, nitrous oxide 3 l x min(-1) in oxygen 3 l x min(-1) and epidural block using 1% mepivacaine. Surgery was completed in 75 minutes. She was extubated without any complications 45 minutes after the end of surgery. Using muscle relaxant in this case with MG and gibbus might place her under artificial ventilation after surgery. For diaphragmatic herniorrhaphy adequate muscle relaxation is necessary. Thus, we used sevoflurane and epidural block. We successfully anesthetized a patient for diaphragmatic herniorrhaphy complicated with myasthenia gravis and gibbus by sevoflurane and epidural block.

Aged↗

PubMed2004

Intrathecal propofol has analgesic effects on inflammation-induced pain in rats.

PURPOSE: Propofol is thought to act on gamma-aminobutyric acid receptors, which have some role in pain transmission in the spinal cord. In this study, we examined the effects of intrathecal propofol on acute thermally- or inflammation-induced pain in rats. METHODS: Lumbar intrathecal catheters were implanted in Male Sprague-Dawley rats. The tail withdrawal response to thermal stimulation (tail flick test) or paw flinching and shaking response by sc formalin injection into the hind paw (formalin test) were tested. Propofol 1000, 300 or 100 microg or saline (control) was administered as 10 microL intrathecally. Motor disturbance and behavioural side effects were also monitored in the rats during the tail flick test. Eight rats were used for each dose in each test. RESULTS: No analgesic effects were observed in the tail flick test. In the formalin test, 50% of effective doses were 449 mug (95% confidence interval, 80-3180 microg) in phase 1 and 275 microg (146-519 microg) in phase 2. Motor disturbance was observed in one rat with 100 microg and agitation and allodynia were seen in one rat with 300 microg. However, both were reversible in 120 min. CONCLUSIONS: Intrathecal administration of propofol had analgesic effects on inflammation-induced acute and facilitated pain but not on thermally-induced acute pain. Transient motor and sensory disturbance could not rule out the possibility of neurotoxicity.

Analgesics↗

PubMed2004

Spinal neurotoxicity and tolerance after repeated intrathecal administration of YM 872, an AMPA receptor antagonist, in rats.

PURPOSE: Although the Alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor antagonist, YM 872, has been considered to be useful in analgesia for both acute and chronic pain, there are no studies of its neurotoxicity and tolerance. We examined the spinal neurotoxicity and tolerance of YM 872 analgesia by repeated intrathecal administration in rats. METHODS: Male Sprague-Dawley rats with lumbar intrathecal catheters received YM 872 at 1 micro g. 10 micro l-1 (eight rats; YM group) or normal saline 10 micro l (eight rats; C group) intrathecally once a day for 30 days. We evaluated the analgesic effects every 3 days, by tail-flick test and behavioral side effects. On the 31st day, the lumbar spinal cord was removed from four randomly selected rats in each group for histological examination. RESULTS: The YM group showed significantly longer tail-flick latency when subjected to a high-intensity light beam than the C group at each measurement time point, although no significant changes in the latency according to the time course of the study were observed for the entire study period of 30 days in either group. No rats showed any side effects. Histologically, only slight lymphocytic cell infiltration and degeneration of myelinated fibers occurred, similarly in both groups. No changes were observed in the spinal cord in either group. CONCLUSION: Administration of YM 872 (1 micro g) once a day for 30 days did not induce any tolerance and caused no histological changes in the spinal cord.

Analgesics↗

PubMed2004

Dose-finding study of intravenous midazolam for sedation and amnesia during spinal anesthesia in patients premedicated with intramuscular midazolam.

PURPOSE: We investigated the effective and safe dose of intravenous midazolam for sedation and amnesia during spinal anesthesia in patients premedicated with intramuscular midazolam. METHODS: One hundred and eighty patients aged 20-50 years scheduled for spinal anesthesia received midazolam 0.06 mg.kg(-1) and atropine 0.01 mg.kg(-1) intramuscularly 15 min before entering the operating room. Spinal anesthesia was performed with 0.5% hyperbaric tetracaine. Five minutes after starting surgery, midazolam 0 (control group), 0.01, 0.02, 0.03, 0.04, or 0.05 mg.kg(-1) was intravenously administered (30 patients each). Blood pressure, heart rate, respiratory rate, percutaneous oxygen saturation (S(p)(O)(2)), verbal response, eyelash reflex, and involuntary body movement were measured every 5 min for 30 min. Memory during surgery was also investigated. RESULTS: The number of the patients with loss of verbal response, with loss of eyelash reflex, and with no memory during surgery were significantly larger in the groups receiving midazolam >or=0.03 mg.kg(-1), >or=0.04 mg.kg(-1), and >or=0.02 mg.kg(-1), respectively. The decrease in blood pressure or increase in respiratory rate with decrease in S(p)(O)(2) was significantly larger in the groups receiving midazolam >or=0.03 mg.kg(-1) or 0.05 mg.kg(-1), respectively. CONCLUSION: For sedation and amnesia of the patients aged 20-50 years in spinal anesthesia with about 1 h duration receiving intramuscular midazolam 0.06 mg.kg(-1) as a premedication, intravenous midazolam 0.02 mg.kg(-1) might be effective and safe.

Adult↗

PubMed2004

Sedation guidelines for midazolam infusion during combined spinal and epidural anesthesia.

STUDY OBJECTIVE: To investigate the adequate infusion dose regimen of midazolam to induce sedation with the Ramsay score 4 with rapid onset during combined spinal and epidural anesthesia DESIGN: Prospective, randomized study. SETTING: Operating room of a university hospital. PATIENTS: 80 ASA physical status I and II patients aged 30 to 70 years, undergoing combined spinal and epidural anesthesia. INTERVENTIONS: Patients were randomized to four groups of 20 patients each at random. After starting surgery, an infusion of midazolam 0.3, 0.6, 0.9, or 1.2 mg/kg/hr was started. When patients closed their eyes spontaneously, the infusion dose was decreased to one half of the initial dose. At 2.5 and 5 minutes after decrease the dose and at 5-minute intervals for the first 30 minutes then at 15-minute intervals thereafter until the end of surgery, infusion dose was adjusted by decreasing to one half or increasing to twice to keep the Ramsay score 4. MEASUREMENTS AND MAIN RESULTS: The number of patients who required oxygen was significantly larger in the groups received 0.9 and 1.2 mg/kg/hr. Eleven patients with 0.9 mg/kg/hr and 17 patients with 1.2 mg/kg/hr at 5 minutes, but no patients with 0.3 or 0.6 mg/kg/hr showed Ramsay score 6 (heavy sedation). Amnesia was observed in all patients. Time to eye closure was dose dependently faster with the larger doses. CONCLUSIONS: During combined spinal and epidural anesthesia, midazolam 0.6 mg/kg/hr given until closing of the eyes (for 1.6 min) followed by midazolam 0.15 mg/kg/hr provides rapidly induced sedation, with a Ramsay score of 4 and amnesia with stable hemodynamics and respiration.

Adult↗

PubMed2004

A comparison of liver function after hepatectomy in cirrhotic patients between sevoflurane and isoflurane in anesthesia with nitrous oxide and epidural block.

UNLABELLED: In this study, we compared postoperative liver function in patients with liver cirrhosis between isoflurane and sevoflurane anesthesia with nitrous oxide (N(2)O) and epidural block. Forty cirrhotic patients with Child-Pugh Grade A, aged 40 to 70 yr, scheduled for liver segmentectomy, had anesthesia induced with midazolam 0.1 mg/kg and fentanyl 4 micro g/kg. For maintenance, intermittent epidural administration of 1.5% lidocaine 4 to 6 mL and sevoflurane (sevoflurane group) or isoflurane (isoflurane group) with N(2)O 3 L/min in oxygen 3 L/min was used. Aspartate aminotransferase, alanine aminotransferase, total bilirubin, alkaline phosphatase, choline esterase, albumin, prothrombin time, and platelet count were measured before and 1, 3, and 7 days after surgery. Aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase increased significantly, with the peaks at 3 days after surgery in both groups. The increases in these variables were significantly larger in the isoflurane group than those in the sevoflurane group. No patient developed hepatic failure. All increases in liver enzymes were small and of questionable clinical relevance. Whether sevoflurane might be a better anesthetic when combined with N(2)O and epidural block for cirrhotic patients than isoflurane with respect to liver damage remains to be determined. IMPLICATIONS: In cirrhotic patients with Child-Pugh Grade A, isoflurane induced more of an increase in serum concentrations of liver enzymes after surgery than sevoflurane when combined with nitrous oxide and epidural block. However, the increases were small, and there was no clinical liver damage.

Adult↗

PubMed2004

Intrathecal clonidine and bupivacaine have synergistic analgesia for acute thermally or inflammatory-induced pain in rats.

UNLABELLED: We investigated the interaction between spinally administered bupivacaine and clonidine using an animal model of acute and inflammatory pain. Rats implanted with lumbar intrathecal catheters were injected intrathecally with saline (control), bupivacaine (1 to 100 microg), or clonidine (0.1 to 3 microg) and tested for their responses to thermal stimulation to the tail (tail flick test) and subcutaneous formalin injection into the hindpaw (formalin test). The effects of the combination of bupivacaine and clonidine on both stimuli were tested by isobolographic analysis. General behavior and motor function were examined as side effects. The 50% effective doses of bupivacaine and clonidine were significantly smaller when combined compared with each single drug in both the tail flick test (2.82 and 0.11 microg versus 7.1 and 0.29 microg, respectively) and phase 1 (0.24 and 0.009 microg versus 5.7 and 0.15 microg) and phase 2 (0.31 and 0.012 microg versus 3.2 and 0.16 microg) of the formalin test. Side effects were decreased by the combination. These results suggest a favorable combination of intrathecal bupivacaine and clonidine in the management of acute and inflammatory pain. IMPLICATIONS: The analgesic interaction between intrathecally administered bupivacaine and clonidine was examined during acute thermal and inflammatory-induced pain in rats. The analgesia produced by the combination of these two drugs was synergistic in both acute thermal and inflammatory induced pain, with a decrease in behavioral side effects.

Adrenergic alpha-Agonists↗

PubMed2004

A comparison of the clinical usefulness of three different electroencephalogram monitors: Bispectral Index, processed electroencephalogram, and Alaris auditory evoked potentials.

UNLABELLED: We compared the usefulness of the Bispectral Index (BIS), Processed electroencephalogram (pEEG), and Alaris auditory evoked potentials (A-AEP). Ninety females scheduled for mastectomy were divided into three groups. Anesthesia was induced with propofol and fentanyl to insert a laryngeal mask airway (LMA) and was maintained by adding nitrous oxide. EEG was monitored by either BIS, spectral edge frequency by pEEG, or A-AEP index by A-AEP. We recorded the number of patients with impedance low enough to extract good EEG signals at the first electrodes application (success rate), the number with an index outside of the range considered appropriate for general anesthesia (inappropriateness rate), changes of the index by LMA insertion or surgical incision (responsiveness), and time to return to good EEG signals after signal disturbance by electric cautery (recovery time). The success rate was larger in BIS > or = A-AEP > pEEG. The inappropriateness rate was smaller in A-AEP < or = BIS , or = pEEG. The A-AEP group showed the largest responsiveness. The recovery time was shorter in pEEG < A-AEP < BIS. In summary, the BIS had the largest success rate, the A-AEP had the least inappropriateness rate and the largest responsiveness, and the pEEG had the fastest recovery time. IMPLICATIONS: We compared the usefulness of three electroencephalogram monitors. The Bispectral Index was the easiest for obtaining low impedance, the auditory evoked potential index had the least inappropriateness rate for general anesthesia and had the largest responsiveness, and the spectral edge frequency was the fastest in stabilizing measurement after electric cautery.

Adult↗

PubMed2004

[A case of ectopic pheochromocytoma of pulmonary origin].

A 55-year-old woman with pulmonary tumor was scheduled for tumor resection. Preoperatively, her episode of paroxysmal hypertension suggested the existence of pheochromocytoma, but MIBG (metaiodo-benzylguanidine) scintigraphy revealed no local accumulation. Therefore, physicians and surgeons denied the possibility of pheochromocytoma. During epidural catheterization, hypertension occurred, which was controlled by diltiazem 2 mg. Anesthesia was induced with midazolam 10 mg, propofol 70 mg and fentanyl 300 microg and maintained with propofol 4-7 mg x kg(-1) x hr(-1), epidural block with 1% mepivacaine and nitrous oxide 66% in oxygen. Manipulation of the tumor induced hypertension. Diltiazem 1-2 microg x kg(-1) x min(-1) and nicardipine 0.4-4 microg x kg(-1) x min(-1) were administered. After tumor resection, blood pressure decreased to 82/42 mmHg and norepinephrine 0.05-0.25 microg x kg(-1) x min(-1) was infused. Norepinephrine infusion was continued for 24 hours after surgery. She was discharged from the recovery room on the third postoperative day without any complications. A case of ectopic pheochromocytoma of pulmonary origin was managed with midazolam, propofol, fentanyl and continuous epidural block. Diltiazem, nicardipine and norepinephrine were administered to control blood pressure.

Anesthesia, Epidural↗

PubMed2004

[A case of giant thyroid tumor with tracheal stenosis].

A 61-year-old female underwent resection of a giant thyroid tumor, and tracheal stenosis ensued. She had cough, dyspnea, and palpitation in the supine position. The giant thyroid tumor was of the size of 11 x 12 cm and the diameter of trachea was 8 x 6 mm at 3.5 cm below the vocal cord, at which point the trachea was the narrowest on cervical computed tomography. The peak expiratory flow rate from the flow-volume curve was 2.94 l x sec(-1) (% predicted value 55.2%) in the upright position. We were concerned about difficult airway management. Oro-tracheal intubation with an armored tube (ID 7.5 mm) was performed after intravenous midazolam 2 mg and fentanyl 50 microg, 4% lidocaine spray 2 ml with oxygen 6 l x min(-1) inhalation keeping spontaneous breathing and consciousness. Anesthesia was induced and maintained with intravenous propofol, fentany, vecuronium and nitrous oxide in oxygen to keep the bispectral index between 40 and 60. The extracted thyroid tumor was 620 g in weight. A careful preoperative evaluation of the airway using ultrasonography, CT, MRI, laryngoscopy, bronchoscopy and respiratory function test, especially peak expiratory flow rate of the flow-volume curve is important in such a case of a giant thyroid tumor. Intubation under conscious sedation with midazolam and fentanyl is useful for a patient with a giant thyroid tumor and tracheal stenosis.

Anesthesia, General↗

PubMed2004

[Case of ventricular tachycardia induced by coronary spasm during surgery in prone position].

A 55-year-old man with hypertension was scheduled for resection of spinal tumor at S1 in the prone position. Anesthesia was induced with midazolam 10 mg, fentanyl 0.2 mg and vecuronium 10 mg, and maintained with sevoflurane 1.5-2% in oxygen 3 l x min(-1) and fentanyl 0.4 mg. When the interspinal ligament was handled, severe ST depression on the ECG was observed for 1 minute, followed by ventricular tachycardia (VT). Immediately, 60 mg of lidocaine was administered intravenously, and ventricular rhythm recovered to sinus rhythm with normal ST level within a few minutes, but the surgery was postponed. In the preoperative examinations, the patient had been evaluated as a low risk case except for a long history of hypertension. Coronary spasm was suspected to have induced VT, because it followed severe ST depression. This experience taught us that in order to avoid critical arrhythmia, patients under general anesthesia, especially those undergoing surgery in the prone position, require particular attention because of the difficulty in cardiac resuscitation.

Anesthesia, General↗