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Hitoshi Furuya

Publications and source records attributed to Hitoshi Furuya.

69 records · Page 4Linked to original sources
PubMed2002

Intraoperative monitoring of myogenic motor-evoked potentials from the external anal sphincter muscle to transcranial electrical stimulation.

STUDY DESIGN: Motor-evoked potentials from the external anal sphincter were analyzed using transcranial electrical stimulation during spinal surgery in patients under general anesthesia. OBJECTIVE: To investigate whether motor-evoked potentials from the external anal sphincter could be elicited by transcranial electrical stimulation under general anesthesia. SUMMARY OF BACKGROUND DATA: Lumbosacral surgery often places nerve rootlets at risk for injury during operative dissection. Specifically, injury for sacral rootlets can result in bowel and bladder dysfunction, but the techniques for monitoring bowel and bladder function are limited. METHODS: Thirty patients who underwent elective spinal surgery were studied. Patients were anesthetized with 50% nitrous oxide in oxygen, fentanyl, and 4 mg/kg/h of propofol (n = 19) or 1 mg/kg/h of ketamine (n = 11). The level of neuromuscular blockade, assessed by recording the M-response from the right abductor pollicis brevis muscle, was maintained at an M-response amplitude of 40-50% of control. Motor-evoked potentials in response to a multipulse transcranial electrical stimulation at stimulus sites of C3-C4 or Fz-Cz were recorded from the skin over the subcutaneous part of the external anal sphincter using a plug-type electrode probe. The success rate of motor-evoked potentials' recording and peak-to-peak amplitude and the onset latency of motor-evoked potentials were evaluated. RESULTS: Success rates of motor-evoked potentials from the external anal sphincter were 73% and 53% after transcranial stimulation at stimulus sites of C3-C4 and Cz-Fz, respectively. Amplitudes of motor-evoked potentials after C3-C4 stimulation were significantly greater than those after Cz-Fz stimulation. Motor-evoked potential latency from the external anal sphincter was 18.6 +/- 1.5 and 19.0 +/- 2.7 msec after C3-C4 and Cz-Fz stimulation, respectively. CONCLUSIONS: The results suggest that, using a transcranial multipulse stimulation, monitoring of motor-evoked potentials from the external anal sphincter is feasible during ketamine- and propofol-based anesthesia. However, further improvement of techniques would be required for intraoperative elicitation of motor-evoked potentials from the external anal sphincter.

Adolescent↗
PubMed2002

A comparison of the INVOS 4100 and the NIRO 300 near-infrared spectrophotometers.

UNLABELLED: We determined whether two different devices for measuring near-infrared spectroscopy (NIRS)---the INVOS 4100 and the NIRO 300---produce similar cerebral oxygenation data during the CO(2) challenge test. Nineteen patients anesthetized with sevoflurane, 67% nitrous oxide in oxygen, and fentanyl were studied. A series of measurements of regional cerebral oxygen saturation (rSO(2)), measured by the INVOS 4100, and tissue oxygen index (TOI), measured by the NIRO 300, were performed in the following conditions: 1) normocapnia (PaCO(2), 35--45 mm Hg); 2) hypocapnia (PaCO(2), 25--35 mm Hg); 3) normocapnia; and 4) hypercapnia (PaCO(2), 45--55 mm Hg). Hemodynamic variables, including arterial blood gases and cerebral blood flow velocity, were measured at the same time with transcranial Doppler. The values and percentage changes of rSO(2) and TOI were compared by using regression analysis and Bland and Altman analysis. The rSO(2) showed a significant positive correlation with TOI (r = 0.58, P < 0.01). The percentage change of rSO(2) also showed a significant positive correlation with the percentage change of TOI during the CO(2) challenge (r = 0.85, P < 0.01). Bland and Altman analysis revealed a bias of -0.5% with 2 SD of 15.6% when comparing the rSO(2) value with the TOI value, and it showed a bias of -3.4% with 2 SD of 15.2% when comparing the percentage change of rSO(2) with the percentage change of TOI, indicating unacceptable disagreement of these data. These results indicate that cerebral oxygen saturation and its relative change during the CO(2) challenge may vary depending on the type of NIRS used. Because the measurement technique and algorithm were different in each device, we should carefully consider the clinical application of the values produced by NIRS. IMPLICATIONS: Near-infrared spectroscopy (NIRS) has been proposed as a noninvasive clinical method for assessing cerebral oxygenation. The acceptable reliability and validity of NIRS values have not been established despite their widespread use. The INVOS 4100 and the NIRO 300 can display cerebral oxygen saturation as regional cerebral oxygen saturation and tissue oxygenation index, but they produce differing results.

Adult↗
PubMed2002

High-dose amrinone is required to accelerate rewarming from deliberate mild intraoperative hypothermia for neurosurgical procedures.

BACKGROUND: Since the time available to provide the cooling and rewarming is limited during deliberate mild hypothermia, the technique to accelerate the cooling and rewarming rate of core temperature has been studied. Amrinone has been reported to accelerate the cooling rate but not the rewarming rate of core temperature during deliberate mild hypothermia. The failure of amrinone effect on the rewarming rate might be due to an insufficient dose of amrinone during hypothermic conditions. The authors therefore tested whether higher doses of amrinone can accelerate the rewarming rate of core temperature during deliberate mild hypothermia for neurosurgery. METHODS: After institutional approval and informed consent, 30 patients were randomly assigned to one of three groups. Patients in the control group (n = 10) did not receive amrinone; patients in the AMR 15 group (n = 10) received 15 microg x kg(-1) x min(-1) amrinone with a 1.0-mg/kg loading dose of amrinone at the beginning of cooling; and patients in the ReAMR group (n = 10) received 5 microg x kg(-1) x min(-1) amrinone with 1.0-mg/kg loading and reloading doses of amrinone at the beginning of cooling and rewarming, respectively. Administration of amrinone was started just after the induction of cooling and continued until the end of anesthesia. Anesthesia was maintained with nitrous oxide in oxygen, propofol, and fentanyl. After induction of anesthesia, patients were cooled, and tympanic membrane temperature was maintained at 34.5 degrees C. After completion of the main surgical procedures, patients were actively rewarmed and extubated in the operating room. RESULTS: The cooling and rewarming rates of core temperature were both significantly faster in both amrinone groups than in the control group. During the cooling and rewarming periods, forearm minus fingertip temperature gradient was significantly smaller in both amrinone groups than in the control group. During the rewarming period, heart rate and mean arterial pressure in the AMR 15 group were significantly faster and lower, respectively, than in the control group. Systemic vascular resistance in the AMR 15 group was smaller than in the control group throughout the study; on the other hand, only the value after the start of rewarming in the ReAMR group was smaller than in the control group. CONCLUSIONS: Amrinone at an infusion rate of 15 or 5 microg x kg(-1) x min(-1) with a reloading at the beginning of rewarming accelerated the rewarming rate of core temperature during deliberate mild hypothermia. This suggests that high-dose amrinone is required to accelerate rewarming from deliberate mild intraoperative hypothermia for neurosurgical procedures.

Adult↗
PubMed2002

Mild hypothermia can enhance pial arteriolar vasodilation induced by isoflurane and sevoflurane in cats.

OBJECTIVE: Volatile anesthetics have been shown to dilate cerebral vessels. Recent evidence suggests that mild hypothermia can alter vascular reactivity of the cerebral vessels. However, the effect of mild hypothermia on volatile anesthetic-induced vasodilation of cerebral vessels is unknown. In the present study, we investigated the effect of mild hypothermia on pial arteriolar vasodilation induced by isoflurane and sevoflurane in cats. DESIGN: Prospective, randomized, experimental study with repeated measures. SETTING: Investigational animal laboratory. SUBJECTS: Forty cats were used for the study of systemic administration of volatile anesthetics, and 22 cats were used for the study of topical administration of volatile anesthetics. INTERVENTIONS: This study was approved by the Animal Experiment Committee of Nara Medical University. Animals were anesthetized with pentobarbital to maintain suppressive electroencephalographic patterns, which were introduced to measure direct effects of anesthetic agents after removing metabolic effects. The cranial window technique, combined with microscopic video recording, was used for the measurement of small (50-100 microm) and large (100-200 microm) pial arteriolar diameter in an experiment. Animals were randomly assigned to either a normothermic (37 degrees C) or a hypothermic group (33 degrees C). Desired temperatures were maintained by using a water blanket. In the first phase of the study, the effect of hypothermia on pial arteriolar vasodilation induced by systemic administration of isoflurane or sevoflurane was assessed. Each cat received isoflurane or sevoflurane at 0.5, 1.0, 1.5, and 2.0 minimum alveolar anesthetic concentrations, and the diameter of pial arterioles was measured. In the second group of animals, the direct effect of isoflurane and sevoflurane on pial vessels was evaluated. The artificial cerebrospinal fluid bubbled with isoflurane or sevoflurane (minimum alveolar anesthetic concentrations of 1 or 3) was topically administered in the cranial window. MEASUREMENTS AND MAIN RESULTS: Systemic and topical administration of isoflurane and sevoflurane produced significant dilation of both small and large pial arterioles in a dose-dependent manner during normothermia. In the hypothermic group, vasodilation of small pial arterioles by systemic administration of isoflurane and sevoflurane at a high concentration was significantly larger than in the normothermic group (p <.05). Vasodilation of both small and large pial arterioles by topical administration of isoflurane and sevoflurane was significantly greater in the hypothermic group than in the normothermic group (p <.05). CONCLUSIONS: These results suggest that pial arteriolar vasodilation induced by isoflurane and sevoflurane can be enhanced by mild hypothermia in cats anesthetized with pentobarbital.

Anesthetics, Inhalation↗
PubMed2002

Effect of mild hypothermia on inodilator-induced vasodilation of pial arterioles in cats.

BACKGROUND: Mild hypothermia has been proposed as a means of providing cerebral protection after traumatic brain injury. However, hypothermia has been shown to alter not only physiologic but also pharmacologic responses. The purpose of this study was to investigate whether mild hypothermia (3-4 degrees C temperature reduction) could alter cerebral vasodilation induced by inodilators, which are characterized by having an inotropic effect in addition to a vasodilatory effect. Isoproterenol (a beta-adrenergic receptor agonist), colforsin dapropate (an adenylate cyclase stimulant), and amrinone (a phosphodiesterase inhibitor) were chosen as inodilators. METHODS: The cranial window technique, combined with microscopic video recording, was used. Forty-eight cats were randomly assigned to either a normothermic or a hypothermic group (33 degrees C). Isoproterenol, colforsin dapropate, or amrinone was topically applied in the cranial window and the diameter of pial arterioles was measured. RESULTS: Topical administration of isoproterenol, colforsin dapropate, and amrinone produced a significant dilation in a dose-dependent manner during normothermia. The vasodilation induced by these inodilators was not affected by mild hypothermia. CONCLUSION: The vasodilation induced by topical administration of isoproterenol, colforsin dapropate, and amrinone was not affected by mild hypothermia.

Administration, Topical↗
PubMed2002

Amplitudes and intrapatient variability of myogenic motor evoked potentials to transcranial electrical stimulation during ketamine/N2O- and propofol/N2O-based anesthesia.

The aim of the current study was to investigate whether there are differences in amplitudes and intrapatient variability of motor evoked potentials to five pulses of transcranial electrical stimulation between ketamine/N2O- and propofol/N2O-based anesthesia. Patients in the propofol group (n = 13) and the ketamine group (n = 13) were anesthetized with 50% N2O in oxygen, fentanyl, and 4 mg/kg/hr of propofol or 1 mg/kg/hr of ketamine, respectively. The level of neuromuscular blockade was maintained at an M-response amplitude of approximately 50% of control. Motor evoked potentials in response to multipulse transcranial electrical stimulation were recorded from the right adductor pollicis brevis muscle, and peak-to-peak amplitude and onset latency of motor evoked potentials were evaluated. To estimate intrapatient variability, the coefficient of variation (standard deviation/mean x 100%) of 24 consecutive responses was determined. Motor evoked potential amplitudes in the ketamine group were significantly larger than in the propofol group (mean, 10th-90th percentile: 380 microV, 129-953 microV; 135 microV, 38-658 microV, respectively; P <.05). There were no significant differences in motor evoked potential latency (mean +/- standard deviation: 20.9 +/- 2.2 msec and 21.4 +/- 2.2 msec, respectively) and coefficient of variation of amplitudes (median [range]: 32% [22-42%] and 26% [18-41%], respectively) and latencies (mean +/- standard deviation: 2.1 +/- 0.7% and 2.1 +/- 0.7%, respectively) between the ketamine and propofol groups. In conclusion, intrapatient variability of motor evoked potentials to multipulse transcranial stimulation is similar between ketamine/N2O- and propofol/N2O-based anesthesia, although motor evoked potential amplitudes are lower during propofol/N2O-based anesthesia than ketamine/N2O-based anesthesia.

Anesthesia↗
PubMed2002

[Sevoflurane can induce rhabdomyolysis in Duchenne's muscular dystrophy].

Rhabdomyolysis is one of the perioperative complications in patients with Duchenne's muscular dystrophy (DMD). It has been suggested that sevoflurane can be used safely for anesthesia in patients with DMD. In this report, we describe a case with DMD who received anesthesia with sevoflurane, in which rhabdomyolysis developed postoperatively. A 6-year-old boy diagnosed as DMD was scheduled for tonsillectomy under general anesthesia. Preoperative laboratory examination revealed a high level of creatine kinase (CK) (16,000-32,000 IU.l-1). An abnormality of the dystrophin gene was detected by DNA analysis. Anesthesia was induced with sevoflurane without muscle relaxant, and maintained with sevoflurane in nitrous oxide and oxygen under controlled ventilation. The course of anesthesia was uneventful and the patient recovered smoothly. Three hours postoperatively, dark red urine with a high concentration of myoglobin (1,390,000 ng.ml-1) was recognized with a high level of CK (63,500 IU.l-1). Body temperature was 37.6 degrees C, and electrocardiogram and serum potassium were within normal ranges. After the diuresis with mannitol and furosemide, the urine became clear. On the 4th postoperative day, he was discharged without any complication. This case suggested that rhabdomyolysis can develop after sevoflurane anesthesia in patients with DMD.

Anesthesia, Inhalation↗
PubMed2002

[Effects of amrinone in patients undergoing off-pump coronary artery bypass grafting].

We evaluated the effect of amrinone in 41 patients undergoing off-pump coronary artery bypass grafting(CABG) retrospectively. Amrinone was intravenously administered at the rate of 5 mcg.kg-1.min-1 after coronary artery anastomosis (A 1 group: 11 cases) or after induction of anesthesia(A 2 group: 13 cases). The hemodynamic variables and use of concomitant drugs were compared among A 1, A 2 and the non-amrinone group (control group: 17 cases). Hemodynamics was measured before, during, after coronary artery anastomosis, and after the chest closure. Catecholamine and vasodilator were used to maintain mean arterial pressure (> 60 mmHg) and cardiac index(> 3.0 l.min-1.m-2). Mean pulmonary artery pressure, right atrial pressure and pulmonary artery wedge pressure were significantly higher during anastomosis than before anastomosis in control and A 1 group, but no significant changes in these parameters were observed in A 2 group. In addition, these variables increased significantly after chest closure in control group, but were unchanged in A 1 and A 2 groups. Patients with concomitant use of catecholamine and vasodilator in A 2 group were fewer than those in control and A 1 group. In conclusion, in the patients undergoing off-pump CABG, infusion of amrinone was recommended from the end of the induction of anesthesia.

Aged↗
PubMed2002

[The relationship between end-tidal isoflurane concentration and electroencephalographic bispectral index during isoflurane/epidural anesthesia].

We studied the effects of increases in isoflurane concentration on the bispectral index (BIS) in 16 patients undergoing lower abdominal surgery during isoflurane/epidural anesthesia. In 8 patients, the lungs were ventilated with an air/oxygen mixture (inspired oxygen fraction 0.33) [N(-) group], and in another 8 patients, the lungs were ventilated with 66% nitrous oxide in oxygen [N(+) group]. During surgery, patients received 1.0 MAC (1.15%) end-tidal isoflurane and the BIS was recorded after 10 min of unchanged end-tidal concentration. After this, we increased the end-tidal concentration of isoflurane by 0.2 MAC to 1.8 MAC. At each concentration step, the BIS was recorded again after 10 min of unchanged end-tidal concentration. At isoflurane concentration < 1.4 MAC, the BIS did not change with increasing isoflurane concentration in both groups (BIS values = about 40). In N (-) group, the BIS decreased in all patients at isoflurane concentration > 1.6 MAC. The mean BIS values were 22 (SD 18) at 1.6 MAC and 2(4) at 1.8 MAC, respectively. In N (+) group, the BIS decreased in four patients at isoflurane concentration > 1.6 MAC, and the BIS did not decrease at 1.8 MAC in another four patients. The mean BIS values were 27 (17) at 1.6 MAC and 21(21) at 1.8 MAC. The present data suggest that BIS may not correlate with anesthetic effect of isoflurane at isoflurane concentration > 1.0 MAC.

Adult↗
PubMed2002

[Paradoxical embolism during MIDCAB surgery].

A 36-year-old woman underwent MIDCAB surgery. During the exposure of LAD, the right ventricular wall was injured. The bleeding was controlled by compression. After that, she developed hypotension followed by cardiac arrest. At the same time, TEE showed bubbles in all of the right ventricle. The open chest massage and epinephrine 1 mg restored the heart beat. It was thought that bubbles were brought to the right ventricle via the injured wall by the blower. A few minutes after the cardiac arrest, bubbles were detected in the left atrium by TEE. This phenomenon was suspected as transpulmonary paradoxical embolism because no cardiac shunt could be detected by TEE.

Adult↗
PubMed2002

[Incidence and duration of hoarseness following endotracheal intubation].

The incidence and duration of hoarseness following tracheal intubation with general anesthesia were studied retrospectively from November 1998 to October 2000 in postanesthetic clinic of Nara Medical University. Total number of patients was 3977 and 37.1% of them complained of hoarseness. Most of there patients recovered within three days after surgery but in 4.2% the hoarshness persisted over ten days and in 0.7% persisted over one month after surgery. Most of these persistent hoarseness were considered to have originated from surgical procedures (such cervical, pulmonary, cardioaortic operation, etc.) and those following only tracheal intubation recovered within two months after surgery. The hoarseness decreased the satisfactory level for anesthesia in 1.0% of total patients and 12.8% of patients with persistent hoarseness. We consider that preoperative explanation and postoperative communication by anesthesiologists are important.

Adult↗
PubMed2002

[Survey Report on International Cooperation 2001--report of the Japanese Society of Anesthesiologists Committee on International Affairs].

A survey was conducted in November 2001 with a questionnaire entitled "Survey Report on International Cooperation" compiled by the International Affairs of the Japanese Society of Anesthesiologists (JSA). The survey focused on member awareness of the importance of international cooperation by sending the questionnaire to its entire membership. Replies were received from approximately 15.6% of the membership or, to be exact, 1,353 JSA members. The survey produced several remarkable findings, which are as follows: 57.8% of the respondents are interested in international cooperation, 86.8% regard international cooperation as necessary, and 38.4% are willing to participate in international cooperation. Those who have actually engaged in international cooperation in the past account for only 7.5%, indicating that there are a good number of members who have not had a chance to provide assistance in international cooperation, their willingness notwithstanding. Regarding their employers' levels of understanding of this issue, 30.6% responded that their managements either recommend active participation or approve of the respondents' intention. Another 24.9% replied that their managements agreed to their participation on condition that they do so privately. Thus, a total of 55.5% of the respondents have permission to participate in international cooperation. Regarding the level of understanding from family members, 41.2% replied that their families agree to their desire irrespective of whether or not their services overseas are relevant to their profession. This figure became 72.4% when their services abroad would be relevant to their profession. On the other hand, 16.0% of the respondents (216 members) stated that they have no interest in international cooperation. For the reasons, 38.8% replied that the issue cannot be viewed as a matter worthy of immediate attention, 10.2% replied that it is not their problem, and 24.1% replied that this will involve dangers. When questioned about their overall impressions from actual participation in international cooperation in the past, among the 102 members responding, 88.2% said they are satisfied with what they have done, 4.9% were undecided as to whether or not they are satisfied, while none of them responded negatively about their services. Of those who are satisfied with their services, as many as 54.4% found their services "worthy of the time spent because of all the excitement involved and because each activity involved work other than their own profession," and 40.0% found them "worthy of their time and labor." Particularly noteworthy is the fact that 6.7% now consider activities in international cooperation "their divinely appointed work in life," and 65.7% hope to participate in international cooperation again. From these findings, it can be deduced that there are few obstacles to the members' international cooperation and that JSA's potential as a promoter of international cooperation may be highly estimated.

Adult↗
PubMedDate not supplied

Systemic meloxicam reduces tactile allodynia development after L5 single spinal nerve injury in rats.

BACKGROUND: Although recent evidence suggests that cyclooxygenase-2 (COX-2) may contribute to the development and management of neuropathic pain, the efficacy of COX-2 inhibitor against neuropathic pain is still unclear. In this study, we investigated the effects of the systemic administration of the selective COX-2 inhibitor meloxicam at an early stage after nerve injury on the development of tactile allodynia in L5 single spinal-nerve injury in rats. METHODS: Twenty-four young male Sprague-Dawley rats received L5 single spinal-nerve injury. Nerve-injured rats (6 per group) received repeated intraperitoneal administrations of meloxicam (1, 2, or 4 mg/kg) or vehicle 0, 12, 24, and 36 hours after nerve injury. Tactile allodynia was quantified for 4 weeks by use of von Frey filaments. RESULTS: In animals given 2 mg/kg and 4 mg/kg, hind-paw withdrawal thresholds 4 weeks after nerve injury were significantly higher compared with those of the vehicle-treated animals. The area under the time-effect curve from preinjury to 4 weeks after nerve injury values were significantly higher in animals treated with 4 mg/kg of meloxicam compared with animals treated with vehicle. CONCLUSION: Systemic administration of 2 mg/kg and 4 mg/kg of meloxicam at an early stage after nerve injury attenuated the development of tactile allodynia. These results suggest that COX-2 may be at least in part involved in the development of tactile allodynia in an L5 single spinal-nerve injury model.

Analgesics, Non-Narcotic↗