Toshiaki Fujisawa

Hokkaido University, Sapporo-shi, Hokkaido, Japan

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Publications (18)14.92 Total impact

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    ABSTRACT: Abstract Klippel-Feil syndrome (KFS) is a rare disease characterized by a classic triad comprising a short neck, a low posterior hairline, and restricted motion of the neck due to fused cervical vertebrae. We report repeated anesthetic management for orthognathic surgeries for a KFS patient with micrognathia. Because KFS can be associated with a number of other anomalies, we therefore performed a careful preoperative evaluation to exclude them. The patient had an extremely small mandible, significant retrognathia, and severe limitation of cervical mobility due to cervical vertebral fusion. As difficult intubation was predicted, awake nasal endotracheal intubation with a fiberoptic bronchoscope was our first choice for gaining control of the patient's airway. Moreover, the possibility of respiratory distress due to postoperative laryngeal edema was considered because of the surgeries on the mandible. In the operating room, tracheotomy equipment was always kept ready if a perioperative surgical airway control was required. Three orthognathic surgeries and their associated anesthetics were completed without a fatal outcome, although once the patient was transferred to the intensive care unit for precautionary postoperative airway management and observation. Careful preoperative examination and preparation for difficult airway management are important for KFS patients with micrognathia.
    Anesthesia Progress 01/2014; 61(3):103-106.
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    ABSTRACT: The neuropeptide Y (NPY) system is known as one of the major neural signaling pathways. NPY, produced by peripheral tissues including osteoblasts, is known to bind to the Y1 receptor. Recently, osteoblast-specific Y1 receptor knockout mice were developed and were found to have a high bone mass phenotype, indicating a role for the NPY-Y1 receptor axis as a regulator of bone homeostasis. However, regulation of Y1 receptor expression during osteoblastic differentiation remains unexplored. In the present study, we examined the role of bone morphogenetic protein (BMP) 2 signaling in regulating Y1 receptor expression. In C2C12 cells, expression of Y1 receptor mRNA was induced by BMP2. This induction was also observed after co-transfection with Smad1 and Smad4, the intracellular signaling molecules of the BMP2 signaling pathway. In a transfection assay, Smad1/4 up-regulated transcriptional activity through interaction with the Y1 receptor gene promoter. Following transfection of MC3T3-E1 cells with siRNA for the Y1 receptor, the expression of ALP, osteocalcin, Runx2 and osterix were increased. These results show that BMP2 signaling regulates Y1 receptor gene expression, and raises the possibility that NPY acts in osteoblasts via an autocrine mechanism.
    Biochemical and Biophysical Research Communications 09/2013; · 2.28 Impact Factor
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    ABSTRACT: Recovery of dynamic balance, involving adjustment of the center of gravity, is essential for safe discharge on foot after ambulatory anesthesia. The purpose of this study was to assess the recovery of dynamic balance after general anesthesia with sevoflurane, using two computerized dynamic posturographies. Nine hospitalized patients undergoing oral surgery of less than 2 h duration under general anesthesia (air-oxygensevoflurane) were studied. A dynamic balance test, assessing the ability of postural control against unpredictable perturbation stimuli (Stability System; Biodex Medical), a walking analysis test using sheets with foot pressure sensors (Walk Way-MG1000; Anima), and two simple psychomotor function tests were performed before anesthesia (baseline), and 150 and 210 min after the emergence from anesthesia. Only the double-stance phase in the walking analysis test showed a significant difference between baseline and results at 150 min. None of the other variables showed any differences among results at baseline and at 150 and 210 min. The recovery times for dynamic balance and psychomotor function seem to be within 150 min after emergence from general anesthesia with sevoflurane in patients undergoing oral surgery of less than 2-h duration.
    Journal of Anesthesia 02/2009; 23(1):57-60. · 0.87 Impact Factor
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    ABSTRACT: Assessing the recovery of dynamic balance after intravenous sedation in the elderly is important for ensuring their safe discharge, especially when they are walking. A reliable, simple dynamic balance test would be useful in daily clinical practice. We observed the recovery of balance after intravenous sedation with midazolam, using computerized dynamic posturography (CDP), and we evaluated the correlation between the CDP result and the results of simple dynamic balance tests. Midazolam was administered in divided doses, until the Wilson sedation score reached 3, in 18 elderly male volunteers. The dynamic balance test using CDP with perturbation stimuli was performed before and after sedation. As simple dynamic balance tests, the usual-speed walking (USW) and maximum-speed walking (MSW) tests and a modified timed "up and go" (TUG) test (subjects stand up from a chair, walk 5 m forward and return to the chair with MSW, and sit down again) were performed. The recovery times (defined as the time until the significant difference between the value at each time point and the baseline value disappeared) in the dynamic balance test (CDP), USW test, MSW test, and TUG test, were 80, 40, 80, 80 min, respectively. There was a significant, strong positive correlation between the result of the dynamic balance test (CDP) and the TUG test (P < 0.01; r = 0.70). The TUG test is a useful simple dynamic balance/motor test that can be used in daily clinical practice in the elderly.
    Journal of Anesthesia 05/2007; 21(2):153-8. · 0.87 Impact Factor
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    ABSTRACT: Dynamic balance involving movement of the centre of gravity is important for the evaluation of street fitness after sedation. The purpose of this study was to compare the recovery of dynamic balance after intravenous sedation with propofol or midazolam, and to investigate the usefulness of simple dynamic balance tests in evaluating the recovery. Fourteen young male volunteers underwent intravenous sedation with propofol and midazolam for 1 h each at an interval of more than 1 week. Computerized dynamic posturography using a multi-axial tilting platform, the 10-m maximum-speed walking test and the timed 'up & go' test (subjects stand up from a chair, walk 5 m and back with maximum speed and sit down again) were performed before and after sedation. The increase in each variable of the tests described above represents a reduction of function. The score of the computerized dynamic posturography was significantly lower in propofol sedation than that in midazolam sedation until 40 min after the end of sedation (P = 0.006). The scores of maximum-speed walking test and timed 'up & go' test were significantly lower in propofol sedation than those in midazolam sedation till 60 min after the end of sedation, respectively (P = 0.035 and 0.042). The timed 'up & go' and maximum-speed walking tests were well and significantly correlated with computerized dynamic posturography in midazolam sedation (timed 'up & go' test vs. computerized dynamic posturography: r = 0.66, P < 0.01; and maximum-speed walking test vs. computerized dynamic posturography: r = 0.53, P < 0.01). The timed 'up & go' and maximum-speed walking tests are useful simple dynamic balance tests well correlated with precise computerized dynamic posturography for the evaluation of the recovery of dynamic balance from midazolam sedation in younger adults.
    European Journal of Anaesthesiology 05/2007; 24(5):425-30. · 2.79 Impact Factor
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    ABSTRACT: We have previously reported that a dynamic balance test with perturbation stimuli and computerised dynamic posturography sensitively reflected the inhibitory effect on balance of intravenous midazolam sedation given intravenously as a single dose, and recovery time was within 80 min. The purpose of this study was to investigate the recovery of dynamic balance after additional doses of midazolam. Eighteen young adult male volunteers were sedated with midazolam given intravenously. The initial dose was given until the Wilson sedation score reached 3, and an additional dose was given until the same score was obtained 40 min later. They were tested with perturbation stimuli 40, 80, 100, and 120 min after the additional doses had been given. Their recovery time was recorded. The mean (S.D.) initial dose of midazolam was 0.07 (0.005) mg kg(-1), and additional doses were 41 (7)% of the initial dose. The serial changes in bispectral index after initial and additional doses were similar. The recovery time for the dynamic balance test (within 80 min) was the same as that recorded in the previous single-dose study. The recovery time of the psychomotor function test was within 75 min. Additional doses of midazolam aiming for a Wilson sedation score of 3 at a dose about 40% of the initial dose and given 40 min after the initial dose are valid in terms of the maintenance of sedation and recovery of dynamic balance. Complete recovery time, including psychomotor function, was within 80 min of the additional dose of the drug.
    British Journal of Oral and Maxillofacial Surgery 05/2007; 45(3):208-11. · 2.72 Impact Factor
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    ABSTRACT: Complete dentures were constructed after tooth extraction for a 71-year-old uncommunicative patient with Alzheimer's disease. Although she had never previously used them, her husband requested the fitting of complete maxillary and mandibular dentures. Thirteen teeth were extracted under local anesthesia and intravenous sedation (IVS), followed by impression-making under IVS. Denture fabrication and adjustment were carried out under mild physical restraint. A tissue conditioner was applied to the fitting surface of the denture base followed by regular denture adjustments. The time required for the patient to eat a meal decreased from 90 minutes without dentures to 30 minutes with dentures due to an improvement in swallowing. Important factors in the successful fitting and use of dentures in this patient were the use of IVS to control behavior during treatment, the treatment plan focused on painless denture use, and oral care by the patient's husband.
    Special Care in Dentistry 01/2007; 27(5):187-90.
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    ABSTRACT: Background and objective: Computerized dynamic posturography using an intentional postural sway task can be used to assess body-leaning ability and postural control ability to prevent falls. Falls are the leading cause of morbidity and mortality for the elderly. The purpose of the present study was to evaluate the recovery of intentional dynamic balance function after intravenous sedation with midazolam in elderly subjects in comparison with that in young subjects. Methods: Midazolam was administered in small, divided doses over 4 to 5 minutes until the Wilson sedation score reached 3 in 20 young and 18 elderly male volunteers. A dynamic limits of stability test, in which subjects leaned their body intentionally as indicated by a cursor moving on a computer screen, was performed before (baseline) and 50, 70, 90, 110, and 130 minutes after administration of midazolam. Results: The changes from baseline values of path sway and movement time 50 minutes after the administration of midazolam in elderly subjects (106.8101.0 %, 4.63.0 seconds; meanSD) were significantly greater than those (32.987.2%, 1.92.8 seconds) in young subjects (p=0.024, p=0.008), respectively. Conclusions: The elderly show slower recovery of the intentional dynamic balance function than do young adults after intravenous sedation with midazolam.
    European Journal of Anaesthesiology 06/2006; · 2.79 Impact Factor
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    ABSTRACT: To assess street fitness after sedation, computerized dynamic posturography (CDP) involving movement of the center of gravity may be more accurate than the conventional computerized static posturography (CSP). The purpose of this study was to evaluate the recovery of dynamic balance function after intravenous sedation by CDP in comparison with CSP, and to find a simple dynamic balance test that is well correlated with CDP. The subjects were 20 male volunteers aged 20-27 years. After intravenous injection of midazolam (0.07 mg . kg(-1)), four balance tests were performed. The recovery time and the percentage of subjects showing recovery (difference from the baseline value < or =10%) were compared. As CDP, a test in which unexpected perturbation stimuli are given using an unstable platform was performed. As CSP, standing sway tests were performed. Maximum speed walking (MSW) and usual speed walking (USW) tests were performed as simple balance tests. The recovery time in CDP (80 min) was longer than that in CSP (40-60 min). The percentage of subjects showing recovery in CDP (20%) was significantly lower than that in CSP (55%-70%) 60 min after the administration of midazolam. There was a significant positive correlation between the CDP test and the MSW test (r = 0.67). CDP with perturbation stimuli detects the balance inhibitory effects of midazolam with greater sensitivity than CSP. The MSW test is well correlated with CDP with perturbation stimuli.
    Journal of Anesthesia 02/2005; 19(1):26-30. · 0.87 Impact Factor
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    ABSTRACT: This retrospective study analyzed the management of 25 patients with hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM), or dilated phase of hypertrophic cardiomyopathy (dHCM) treated in the outpatient clinic of the Department of Dental Anesthesiology at Hokkaido University. A total of 87 dental treatment sessions were completed. Intravenous sedation was used significantly more often for patients with HCM than those who had DCM. This seemed to be because dental anesthesiologists expected sedative drugs to suppress hyperdynamic circulatory changes caused by mental stress. Intraoperative complications occurred during 19 treatments. The incidence of circulatory complications increased when participants with DCM also reported dental fear. For participants with HCM who reported dental fear, circulatory complications occurred only when sedation was not used. It is not clear whether complications were related to cardiac function or dental treatment. Therefore, it is important to continually monitor patients with these conditions and to be prepared to handle complications that may arise during dental treatment.
    Special Care in Dentistry 10/2003; 23(6):216 - 222.
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    ABSTRACT: Objective: The purpose of this study was to investigate the optimal dosage of intravenous midazolam for sedation in elderly patients and compare the amount of depression of respiratory function and skeletal muscle activity after obtaining similar sedation levels in younger patients.Patients and Methods: Fifteen elderly patients older than 65 years (group E) and 15 patients younger than 55 years (group Y) underwent oral surgery or dental treatment with or without local anaesthesia after intravenous administration of midazolam.Results: The optimal dose for the elderly patients was 62% that for the younger patients. The duration of depression of arterial oxygen saturation and vital capacity was more prolonged among patients in group E than in those in group Y. The number of patients whose grip strength value recovered 15 and 30 minutes after administration of midazolam was significantly smaller for group E than for group Y.Conclusion: These results suggest that elderly people should be carefully treated with attention to the decrease in skeletal muscle activity, including respiratory and upper airway muscles, when receiving intravenous sedation with midazolam.
    Asian Journal of Oral and Maxillofacial Surgery 12/2002; 14(4):209–214.
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    ABSTRACT: To investigate the differences in recovery of postural stability, after obtaining similar intravenous sedation levels with midazolam, in elderly and younger patients undergoing dental surgery. We studied 15 elderly patients (>65 years) and 15 younger patients (<55 years) after intravenous sedation. Midazolam was carefully titrated over 4-5 min until slow response to verbal commands, ptosis of the eyelid, or slight slurring of speech was obtained. Parameters were postural balance tests and an addition test, as a psychomotor function test. The dose of midazolam in the elderly group (0.045 +/- 0.012 mg.kg(-1)) was 62% of that in the younger group (0.074 +/- 0.026 mg.kg(-1)). In evaluation of the percentile rank of a balance test with a visual feedback system, which contained a dynamic balance element, recovery at 60 min in the elderly group was significantly slower than that in the younger group. However, the recovery times for the balance test and the addition test, at which the significantly changed values were restored to the baseline values, were 120 min and 90 min, respectively, in both groups. In the recovery from sedation, elderly patients had more difficulty in acquiring postural adjustment during movement than in maintaining a standing posture. If the dose is carefully administered, however, even elderly patients might be able to return home 2 h after midazolam administration, as could the younger patients.
    Journal of Anesthesia 01/2002; 16(3):198-202. · 0.87 Impact Factor
  • Journal of Anesthesia 02/2001; 15(2):100-3. · 0.87 Impact Factor
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    ABSTRACT: Changes in the hormones responsible for volume homeostasis were observed before, during, and after minor dental surgery in 25 elderly hypertensive patients. These patients were divided into two groups. Group L patients were operated on using local anesthesia alone. Group LS patients were operated on using local anesthesia and intravenous sedation together. We found that plasma renin activity and aldosterone and vasopressin levels did not change intraoperatively in either group. We also found that intraoperative plasma human atrial natriuretic peptide (HANP) levels and systolic blood pressure were significantly elevated in group L and significantly decreased in group LS. Before local anesthesia was administered, HANP levels in both groups were already higher than the normal range in healthy adults. Therefore, these results suggest that increased HANP levels represent a compensatory response to offset further elevation of blood pressure. However, these increases did not seem to be sufficient to actually cause a decrease in blood pressure.
    Anesthesia Progress 02/1998; 45(3):103-9.
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    ABSTRACT: Geriatric patients who undergo intravenous sedation require careful intraoperative management, because respiratory and circulatory depression usually accompanies the administration of recommended adult sedative doses. This study examined results when a single benzodiazepine, diazepam or flunitrazepam, was carefully titrated to a clinical endpoint of conscious sedation. A total of 335 cases was divided into seven age groups. Mean sedative doses gradually decreased with age. The 60- to 69-yr group required about 75% of the adult recommended dose, the 70- to 79-yr group required 40% to 60%, and the 80- to 89-yr group required 30% to 45%. Pulse oximetry values also declined with age; respiratory depression was observed mainly in elderly patients. Declines in blood pressure after benzodiazepine administration were not correlated with age. The rise in blood pressure normally observed intraoperatively was suppressed both in young as well as old patients. We conclude that intravenous conscious sedation in elderly patients reduces stress-induced cardiovascular stimulation and that respiratory depression may occur at even low sedative doses.
    Anesthesia Progress 02/1992; 39(3):73-8.
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    Anesthesia Progress 01/1989; 36(4-5):230-4.
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    ABSTRACT: This retrospective study analyzed the management of 25 patients with hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM), or dilated phase of hypertrophic cardiomyopathy (dHCM) treated in the outpatient clinic of the Department of Dental Anesthesiology at Hokkaido University. A total of 87 dental treatment sessions were completed. Intravenous sedation was used significantly more often for patients with HCM than those who had DCM. This seemed to be because dental anesthesiologists expected sedative drugs to suppress hyperdynamic circulatory changes caused by mental stress. Intraoperative complications occurred during 19 treatments. The incidence of circulatory complications increased when participants with DCM also reported dental fear. For participants with HCM who reported dental fear, circulatory complications occurred only when sedation was not used. It is not clear whether complications were related to cardiac function or dental treatment. Therefore, it is important to continually monitor patients with these conditions and to be prepared to handle complications that may arise during dental treatment.
    Special Care in Dentistry 23(6):216-22.
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    Anesthesia Progress 36(4-5):169-71.