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Biomedical subjects

Hitoshi Furuya

Publications and source records attributed to Hitoshi Furuya.

At least 19 recordsLinked to original sources
PubMed2006

Delta opioid receptors stimulation with [D-Ala2, D-Leu5] enkephalin does not provide neuroprotection in the hippocampus in rats subjected to forebrain ischemia.

It has been reported that delta opioid agonists can have neuroprotective efficacy in the central nervous system. This study was conducted to test the hypothesis that a delta opioid receptor (DOR) agonist, [D-Ala2, D-Leu5] enkephalin (DADLE), can improve neuron survival against experimental forebrain ischemia in rats. Using male rats (n=125), intraperitoneal injection of DADLE (0, 0.25, 1, 4, 16 mg kg-1) was performed 30 min before ischemia. Ten minutes interval forebrain ischemia was provided by the bilateral carotid occlusion combined with hypotension (35 mm Hg) under isoflurane (1.5%) anesthesia. All animals were neurologically and histologically evaluated after a recovery period of 1 week. As histological evaluation, percentages of ischemic neurons in the CA1, CA3, dentate gyrus (DG) were measured. During the recovery period, 27 rats died because of apparent upper airway obstruction, seizure, or unidentified causes. There were no differences in the motor activity score among the groups. Ten minutes forebrain ischemia induced approximately 75, 20, and 10% neuronal death in the CA1, CA3, and DG, respectively. Any doses of DADLE did not attenuate neuronal injury in the hippocampus after ischemia. Pre-ischemic treatment of DORs agonism with DADLE did not provide any neuroprotection to the hippocampus in rats subjected to forebrain ischemia.

Analgesics, Opioid↗
PubMed2006

Effects of neuromuscular block on systemic and cerebral hemodynamics and bispectral index during moderate or deep sedation in critically ill patients.

OBJECTIVE: To investigate whether neuromuscular block can affect bispectral index (BIS) or cerebral hemodynamics under moderate or deep sedation produced by propofol. DESIGN AND SETTING: Prospective, controlled study in a university hospital affiliated intensive care unit. PATIENTS: Seventeen surgical patients undergoing elective esophagectomy. INTERVENTIONS: After stabilization with either light or deep sedation we investigated whether the BIS, electromyographic activity (EMG), or cerebral and systemic hemodynamic parameters were affected by administration of muscle relaxant. MEASUREMENTS AND MAIN RESULTS: Neuromuscular block reduced the BIS during moderate sedation but not during deep sedation although the EMG at both levels of sedation was significantly reduced. No positive effects of neuromuscular block on cerebral hemodynamics were obtained with monitoring of regional cerebral oxygen saturation and middle cerebral artery blood velocity; however, significant effects on systemic hemodynamic parameters were observed only at moderate propofol sedation. The values of BIS and systemic hemodynamic variables with moderate sedation were also very similar to those with deep sedation and neuromuscular block although these values differed without neuromuscular block. CONCLUSIONS: Neuromuscular block altered the BIS score in moderately sedated patients but not in deeply sedated patients although cerebral hemodynamics was not affected by neuromuscular block during either moderate or deep sedation. Muscular relaxant also enhanced cardiovascular stability with moderate sedation. These results suggest that level of consciousness may be decreased by neuromuscular block during moderate sedation but not affected during deep sedation.

Aged↗
PubMed2006

Effects of increasing concentrations of propofol on jugular venous bulb oxygen saturation in neurosurgical patients under normothermic and mildly hypothermic conditions.

BACKGROUND: Recent evidence suggested that propofol can deteriorate the cerebral oxygen balance compared with inhalational anesthetics. However, dose-related influences of propofol on cerebral oxygen balances were not clearly investigated. In the current study, the authors investigated the effects of increasing concentrations of propofol on jugular venous bulb oxygen saturation (Sj(O2)) in neurosurgical patients under normothermic and mildly hypothermic conditions. METHODS: After institutional approval and informed consent were obtained, 30 adult patients undergoing elective craniotomy were studied. Patients were randomly allocated to either normothermic or hypothermic group (n = 15 in each group). In the normothermic and hypothermic groups, tympanic membrane temperature was maintained at 36.5 degrees and 34.5 degrees C, respectively. Sj(O2) was measured at predicted propofol concentrations of 3, 5, and 7 microg/ml using a target-controlled infusion system in both groups. RESULTS: At a predicted propofol concentration of 3 microg/ml, there were no significant differences in Sj(O2) values between the normothermic and hypothermic groups, although the incidence of desaturation (Sj(O2) < 50%) was significantly higher in the normothermic group than in the hypothermic group (30% vs. 13%; P < 0.05). Sj(O2) values and the incidence of desaturation remained unchanged during the changes in predicted propofol concentration from 3 to 7 microg/ml both in the normothermic and hypothermic groups. CONCLUSION: The results indicated that the increasing concentrations of propofol did not affect Sj(O2) values in neurosurgical patients under normothermic and mildly hypothermic conditions.

Adult↗
PubMed2006

Reevaluation of gray and white matter injury after spinal cord ischemia in rabbits.

BACKGROUND: Although gray matter injury has been well characterized, the available data on white matter injury after spinal cord ischemia (SCI) in rabbits are limited. The current study was conducted to investigate the evolution of ischemia induced injury to gray and white matter and to correlate this damage to hind-limb motor function in rabbits subjected to SCI. METHODS: Thirty-eight rabbits were randomly assigned to 24-h, 4-day, or 14-day reperfusion groups or a sham group (n = 9 or 10 per group). SCI was induced by occlusion of the infrarenal aorta for 16 min. Hind-limb motor function was assessed using the Tarlov scale (0 = paraplegia, 4 = normal). The gray matter damage was assessed on the basis of the number of normal neurons in the anterior spinal cord. White matter damage was assessed on the basis of the extent of vacuolation and accumulation of amyloid precursor protein immunoreactivity. RESULTS: Tarlov scores gradually decreased and reached a nadir 14 days after reperfusion. There were no significant differences in the number of normal neurons among the 24-h, 4-day, and 14-day groups. The extent of vacuolation, expressed as a percent of total white matter area, was significantly greater in the 4-day and 14-day groups in comparison with the sham group. By contrast, there was no difference in vacuolation between the sham and 24-h groups. Amyloid precursor protein immunoreactivity was greater in the 4-day and 14-day groups. CONCLUSION: The results in the current study show that SCI induced white matter injury as well as gray matter injury in a rabbit model of SCI. The time course for 14 days after reperfusion may differ among the gray and white matter damages and hind-limb motor function in rabbits subjected to SCI.

Amyloid beta-Protein Precursor↗
PubMed2006

The effects of xenon on myogenic motor evoked potentials in rabbits: a comparison with propofol and isoflurane.

We compared the effects of xenon on myogenic motor evoked potentials (MEPs) with those of propofol and isoflurane in rabbits under ketamine/fentanyl anesthesia. Thirty animals were randomly allocated to one of 3 groups (n = 10 in each group). In the propofol group, propofol was administered at a rate of 0.4 mg x kg(-1) x min(-1) (small) and 0.8 mg x kg(-1) x min(-1) (large). In the isoflurane group, isoflurane was administered at 0.8% (small) and 1.6% (large). In the xenon group, xenon was administered at 35% (small) and 70% (large). Myogenic MEPs in response to stimulation with single pulse and a train of 5 pulses were recorded from the soleus muscle before, during (at small and large doses), and after the administration of each anesthetic. With single-pulse stimulation, MEPs were recorded in 90% and 50% of animals at small and large doses of xenon, respectively, and MEP amplitudes in the xenon and isoflurane groups were significantly lower compared with those in the propofol group. With train pulse stimulation, MEPs were recorded in 100% and 90% of animals at small and large doses of xenon, respectively, and a reduction in MEP amplitudes by xenon was more prominent than by propofol but less than isoflurane at large doses. These results suggest that MEP recording may be feasible under xenon anesthesia if multipulse stimulation is used, although xenon has suppressive effects on myogenic MEPs.

Anesthetics, Inhalation↗
PubMed2006

[Prophylactic use of droperidol for postoperative nausea and vomiting following gynecological laparoscopic surgery under total intravenous anesthesia].

BACKGROUND: Propofol and droperidol decrease the incidence of postoperative nausea and vomiting (PONV). We investigated the incidence of PONV after total intravenous anesthesia (TIVA) with propofol alone versus combined use of droperidol and propofol. METHODS: Eighty three patients, who had undergone laparoscopic gynecologic surgery with TIVA using propofol and fentanyl, were retrospectively evaluated whether droperidol had affected the incidence of early (up to six hours postoperatively) and late (6-24 hours postoperatively) PONV. Group D (46 patients) received droperidol intravenously at the end of surgery. Group N (37 patients) received no droperidol. RESULTS: The incidences of early nausea were 27% in Group N and 4% in Group D (P<0.01). The incidences of early vomiting were 0% in Group N and 8% in Group D. The incidences of late nausea were 14% in Group N and 13% in Group D. The incidences of late vomiting were 3% in Group N and 7% in Group D. CONCLUSIONS: Droperidol was useful in reducing the incidence of early nausea and vomiting after total intravenous anesthesia with propofol and fentanyl in the patients undergoing laparoscopic surgery.

Adult↗
PubMed2006

[Ilioinguinal nerve block during general anesthesia for inguinal herniorrhaphy in adult anticoagulated patients].

Two adult anticoagulated patients after valve replacement were scheduled for inguinal herniorrhaphy. For inguinal herniorrhaphy in adults, spinal anesthesia is a common anesthetic method. In order to avoid spinal hematoma due to spinal anesthesia, however, we employed general anesthesia combined with ilioinguinal nerve block. Following induction of anesthesia, a laryngeal mask airway was inserted. Ilioinguinal nerve block was performed with 0.25% bupivacaine 20ml. Ilioinguinal nerve block was effective for maintaining hemodynamic stability throughout the operation, and decreased postoperative pain. This technique appears to be a simple and safe method for providing effective and long-lasting perioperative analgesia following inguinal herniorrhaphy in adult patients.

Aged↗
PubMed2006

[Motor evoked potentials].

Motor dysfunction following spinal surgery and thoracoabdominal aortic surgery remain as one of their devastating complications. Since the development of postoperative motor dysfunction can deteriorate quality of life of patients, the prevention of such complications is an important clinical challenge. Recently, advances in stimulation technique using multipulse made intraoperative monitoring of functional integrity of motor pathways possible by recording myogenic motor evoked potentials (MEPs). However, myogenic MEPs can be affected by most of anesthetic agents and muscle relaxants. Anesthesiologists are therefore required to properly understand MEPs and to manage anesthesia carefully. We summarize the methods for monitoring of myogenic MEPs and anesthetic techniques during intraoperative MEP monitoring.

Anesthesia↗
PubMed2006

[Clinical characteristics of perioperative pulmonary thromboembolism in Japan--Results of the perioperative thromboembolism research in the Japanese Society of Anesthesiologists].

BACKGROUND: Although we reported the perioperative mortality to be 4.41 (per 10000 cases) and morbidity to be 18.0% with the pulmonary thromboembolism (PTE) in Japan based on the research conducted by the Japanese Society of Anesthesiologists (JSA), the characteristics of these patients have not yet been assessed. METHODS: Results of 809 registry cases of perioperative PTE patients were analyzed regarding the differences in gender, characteristics of obesity, cases that resulted in death, feature of PTE cases with abdominal surgery and hip/lower extremity surgery, and changes in the results of two researchs. RESULTS: Considerably higher number of obesity cases were observed in women than in men, and the obesity rate was approximately 1.5-3-times higher in men than that observed in the general female population. The predictors of mortality were old age, long-term rest and gender (male). More than 80% of the patients who had undergone abdominal surgery contracted PTE in the postoperative period; but, more than 60% of the patients who had undergone hip/lower limb surgery along with a bone fracture contracted PTE in the preoperative or intra-operative periods. When compared with the results of the research carried out in 2002 and 2003, the incidence around caesarean section appeared to have decreased significantly (P = 0.016), and use of elastic stoking and intra-pneumonic compression appeared to have increased significantly (P<0.01). However, the rate of using anticoagulant drugs appeared to remain unchanged. CONCLUSIONS: The results of this study indicate the clinical characteristics of patients with perioperative PTE in Japan, the predictors of perioperative mortality, and the changes observed between the results of the researches carried out in 2002 and 2003.

Age Factors↗
PubMed2006

[Incidence and characteristics of perioperative pulmonary thromboembolism in Japan in 2004].

BACKGROUND: The incidence of perioperative pulmonary thromboembolism (PTE) is reported not to be low in Japan. The aim of this study is to investigate the incidence and characteristics of perioperative PTE in Japan in 2004. METHODS: A questionnaire was mailed to 960 institutions registered as the teaching hospitals of the Japanese Society of Anesthesiologists (JSA). The survey details included age, sex, type of surgery, and risk factors of patients operated in 2004. RESULTS: Effective responses were received from 642 institutions (66.9%) of 960 institutions. A total of 409 cases of perioperative PTE were reported from 245 institutions (25.5% of the institutions responded). The incidence of perioperative PTE was 3.62 per 10,000 cases. Cardiac arrest occurred at the onset in 65 cases (15.9%). Of the patients, 150 (36.7%) had malignancy; 142 (34.7%) were obese; and 121 (29.6%) were bed-ridden (> 4 days). In 273 cases (66.7%), the patients were over 60 years of age. PTE was found to be more frequent in females than in males (males, 147 cases; females, 259 cases). The types of surgery resulted in perioperative PTE with high frequency were "spinal surgery" (6.95 per 10,000 cases) and "limbs and/or hip joint surgery" (9.79 per 10,000 cases). Eighty-nine patients (21.8%) died from perioperative PTE. CONCLUSIONS: The incidence of perioperative PTE was not low and its mortality was high in Japan in 2004. In particular, the incidence of perioperative PTE was found to be high in females, the elderly, patients with malignancy, and patients who had undergone orthopedic surgery.

Adolescent↗
PubMed2006

Proper use of phosphodiesterase inhibitors according to the situations.

We came across a case who because of sustained hypotension with normal cardiac output was given amrinone which offered an initial excellent response but showed impotency later and its replacement by milrinone dramatically improved the hemodynamic status. The ensuing hypotension was thought to be the consequence of the use of amrinone which was given to treat hypotension in conjunction with fluid therapy; besides, it also induced pulmonary hypertension. Therefore, milrinone was given to replace amrinone and was successfully to turn the tide. It is our suggestion that if the use of a phosphodiesterase (PDE) inhibitor is indicated but its side effects are enhanced to refute its use, the application of a different PDE inhibitor should be kept in mind.

Aged↗
PubMed2006

Sevoflurane is safe for anesthetic management in patients with multiple sclerosis.

We report a safe anesthetic management of patients with multiple sclerosis (MS) using sevoflurane. A 34-yr-old female patient with a 2-yr history of MS was scheduled for gynecological surgery. Anesthesia was induced with propofol and fentanyl and maintained with sevoflurane, nitrous oxide, and fentanyl. Vecuronium was used for tracheal intubation. The patient showed rapid emergence from anesthesia. Exacerbation of symptoms of MS was negative according to the neurologic assessment at that time. Postoperative pain was managed mainly with continuous venous infusion of fentanyl instead of neural block with local anesthetics. Transient fever due to subcutaneous infection of the surgical site was observed and topical drainage was required. Eventually, postoperative exacerbation of symptoms of MS compared with preoperative status did not appear. In conclusion, sevoflurane does not induce exacerbation of symptoms and facilitates early postoperative neurologic assessment, therefore, it is one of ideal anesthetics for MS patients.

Adult↗
PubMed2005

Positive inotropic effect of nicorandil in adult rats in situ.

PURPOSE: Although the cardiac protective and negative inotropic effects of nicorandil via opening the sarcolemmal or mitochondrial K(ATP) channel and NO-like action are well known, positive inotropic effects of nicorandil in normal hearts have not been reported. The aim of the current study was to investigate how nicorandil affects left ventricular (LV) function of in situ adult rat hearts through the entire cardiovascular system. METHODS: We performed simultaneous and continuous measurements of LV pressure (P) by a catheter-tip micromanometer and LV volume (V) using a conductance catheter. We obtained steady-state LV P-V loops and intermittent curvilinear LV end-systolic pressure-volume relations (ESPVRs), LV end-systolic pressure (ESP(mLVV)), and systolic pressure-volume area (PVA(mLVV)) at midrange LVV (mLVV). We evaluated the effects of nicorandil on LV function by these mechanical indexes sensitively reflecting changes in LV contractility and work capability, preload (end-diastolic volume, EDV), and afterload (effective arterial elastance, Ea). RESULTS: Nicorandil (10 and 20 microg.kg(-1).min(-1)) (blood concentration: 0.53 +/- 0.14 and 1.48 +/- 0.21 microg/ml) largely shifted ESPVR upward and thus significantly increased ESP(0.06), PVA(0.06), stroke volume due to increase in EDV, and ejection fraction without significant changes in Ea and heart rate. In contrast, an NO donor, nitroglycerin (1 microg.kg(-1) . min(-1)), significantly decreased Ea but did not change ESP(0.06), PVA(0.06), and EDV. Furthermore, either a nonselective K(ATP) channel blocker, glybenclamide, or a mitochondrial K(ATP) channel blocker, 5-hydroxydecanoate, abolished these nicorandil-induced positive inotropic actions. CONCLUSION: These results suggest that nicorandil exhibited positive inotropic actions on LV function of in situ hearts in adult rats with resultant increased preload (EDV).

ATP-Binding Cassette Transporters↗
PubMed2005

Neuroprotective effects of anesthetic agents.

Ischemic neuronal injury is characterized by early death mediated by excitotoxicity and by delayed death caused by apoptosis. Current evidence indicates that volatile agents, barbiturates, and propofol can protect neurons against ischemic injury caused by excitotoxicity. In the case of volatile agents and propofol, neuroprotection may be sustained if the ischemic insult is relatively mild; however, with moderate to severe insults, this neuronal protection is not sustained after a prolonged recovery period. This suggests that volatile agents and propofol do not reduce delayed neuronal death caused by apoptosis. The long-term effects of barbiturates on ischemic cerebral injury are not yet defined. Cerebral ischemia is characterized by continued neuronal loss for a long time after the initial ischemic insult. Therefore, in investigations of cerebral ischemia, the duration of the recovery period should be taken into consideration in the analysis of the neuroprotective effects of anesthetic agents. A combination of different approaches that target specific stages of the evolution of ischemic injury may be required for sustained neuroprotection.

Anesthetics↗
PubMed2005

Tetanic stimulation of the peripheral nerve before transcranial electrical stimulation can enlarge amplitudes of myogenic motor evoked potentials during general anesthesia with neuromuscular blockade.

BACKGROUND: Neuromuscular blockade can suppress myogenic motor evoked potentials (MEPs). The authors hypothesized that tetanic stimulation (TS) of the peripheral nerve before transcranial stimulation may enhance myogenic MEPs during neuromuscular blockade. In the current study, the authors evaluated MEP augmentations by TS at different levels of duration, posttetanic interval, neuromuscular blockade, and stimulus intensity. METHODS: Thirty-two patients undergoing propofol-fentanyl-nitrous oxide anesthesia were examined. Train-of-five stimulation was delivered to C3-C4, and MEPs were recorded from the abductor hallucis muscle. In study 1, TS with a duration of 1, 3, or 5 s was delivered at 50 Hz to the tibial nerve 1, 3, or 5 s (interval) before transcranial stimulation, and the effects of TS on MEP amplitude were evaluated. In study 2, TS-induced MEP augmentations were evaluated at the neuromuscular blockade level (%T1) of 50% or 5%. In study 3, MEP augmentations by TS at stimulus intensities of 0, 5, 25, and 50 mA were evaluated. RESULTS: The application of TS significantly enlarged the amplitudes of MEPs at the combinations of duration (3, 5 s) and interval (1, 3, 5 s) compared with those without TS. TS-induced MEP augmentations were similarly observed at %T1 of both 50% and 5%. TS-induced MEP augmentations were observed at stimulus intensities of 25 and 50 mA. CONCLUSIONS: The results indicate that TS of the peripheral nerve before transcranial stimulation can enlarge the amplitude of MEPs during general anesthesia with neuromuscular blockade. TS of the peripheral nerve can be intraoperatively applied as a method to augment myogenic MEP responses.

Aged↗
PubMed2005

Effects of nitrous oxide on spike activity on electrocorticogram under sevoflurane anesthesia in epileptic patients.

We sought to investigate the effects of nitrous oxide on intraoperative electrocorticogram (ECoG) spike activities in 11 patients with intractable epilepsy. Grid electrodes were placed on the brain surface, and ECoG was recorded under the following conditions: 1.5 minimal alveolar anesthetic concentration (MAC) sevoflurane without nitrous oxide and 1.5 MAC sevoflurane with 50% nitrous oxide. The number of spikes for 5 minutes and the percentage of leads with spikes of total leads measured were assessed in each condition. The median numbers (25-75th) of spikes without and with nitrous oxide were 127 (87-368) and 61 (43-247), respectively. The numbers of spikes with nitrous oxide were significantly lower than those without nitrous oxide (P<0.05). The median percentages of leads with spikes without and with nitrous oxide were 68 (25-81) and 61 (28-70), respectively, and there were no significant differences in percentages of leads with spikes between the conditions. These results indicate that nitrous oxide attenuated the frequency of spikes on ECoG in epileptic patients, although it did not affect the extent of areas with spike activity.

Adult↗
PubMed2005

Evaluation of relatively low dose of oral transmucosal ketamine premedication in children: a comparison with oral midazolam.

BACKGROUND: Oral Transmucosal ketamine (lollipop) has been shown to be an effective, harmless preoperative medication for children. However, its efficacy was not compared with commonly used premedication drugs. We, therefore, compared the efficacy of oral transmucosal ketamine with oral midazolam for premedication in children. METHODS: Fifty-five children (2-6 years of age) were randomized to receive orally either a lollipop containing 50 mg of ketamine (the group K; n = 27) or syrup containing 0.5 mg.kg(-1) of midazolam (the group M; n = 28) before minor surgery. A five points-sedation score (1 = asleep to 5 = agitated; scores 2 and 3 were defined as 'effective') on arrival in the operating room and a three points-acceptance score of separation from the parents and a three points-mask cooperation score at induction of anesthesia (1 = easy to 3 = markedly resistant; score 3 was defined as 'poor') were used. RESULTS: Sedation scores in group K were significantly higher than those in group M (P = 0.012), and the incidence of 'effective' in sedation was significantly lower in group K than in group M (P = 0.036). The incidence of 'poor' at separation from the parents and for mask cooperation was significantly higher in group K than in group M (P = 0.017, P = 0.019, respectively). CONCLUSION: These results indicate that a relatively low dose of oral transmucosal ketamine premedication provides no benefits over oral midazolam in children.

Administration, Buccal↗