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Biomedical subjects

H Tsuchida

Publications and source records attributed to H Tsuchida.

At least 109 records · Page 6Linked to original sources
PubMed1993

[Intraoperative management and prognosis of patients for emergency cardiovascular surgery].

We analyzed patient characteristics, the management of anesthesia, and prognosis, etc. in 13 patients for emergency valvular heart surgery (V) and 28 patients for emergency aortic surgery (A). The patients in group A were significantly older than those in the group V. Fentanyl was used as the main anesthetic agent in all patients in the group V and in most of the patients in the group A. Five patients undergoing abdominal aortic surgery in the group A received epidural anesthesia concomitantly with general anesthesia. Postoperatively more than half of the group V patients required some kind of mechanical support, such as IABP, to maintain hemodynamic stability, as well as catecholamine infusion which all of the group V patients received. Six of the 13 patients in the group V died postoperatively. They had received prosthetic aortic valve replacement. Three of them died from LOS and the other 3 from MOF. Seven of the 28 patients in the group A died perioperatively. They all had had descending thoracic aortic aneurysm. Gastrointestinal tract bleeding and/or necrosis were seen in 4 of the 6 patients who died postoperatively. We found that the prognosis of emergency cardiovascular surgery is quite poor, and anesthesiologist should take sufficient care in the management of these patients throughout the perioperative period.

Aged↗
PubMed1993

[Cerebral blood flow velocity and electroencephalogram for the evaluation of intraoperative brain function during intrathoracic hyperthermia].

It is well known that progressive hyperthermia exerts fatal damage on the human body. However, there have been few reports on the brain function or the means to provide adequate monitoring during hyperthermia. The purpose of this study was to introduce two new devices, the Life Scan electroencephalogram (EEG) Monitor (Neurometrics) and the TC2-64 (EME) transcranial Doppler sonography (TCD), both for monitoring brain function during hyperthermia. The Life Scan uses aperiodic analysis, which maps each waveform in relation to its frequency, amplitude, and time of occurrence rather than averaging a large number of waveforms over a given period. The Life Scan shows 80% of the whole amplitude of each wave as the activity edge (AE). The flow velocity of the middle cerebral artery was measured by TCD during hyperthermia. After the induction of modified neuroleptanesthesia (fentanyl and midazolam), AE was maintained at 11 Hz. With an increase in body temperature, AE gradually showed a trend toward a slow wave, though the slowing of EEG was interrupted when the patient awoke to slight stimulation. Therefore, it is speculated that the slowing of EEG in this case was caused by fentanyl. The mean cerebral blood flow velocity increased slightly from 28 to 32 cm.sec-1 by hyperthermia. It is concluded that the adoption of EEG and TCD was useful in determining the intraoperative cerebral function during hyperthermia.

Brain↗
PubMed1992

Hemodynamic responses during induction of anesthesia with halothane-nitrous oxide in children with or without atropine premedication.

Forty three children ranged from 1 yr. to 6 yr. were randomly assigned to non-atropinized group (n = 20; A(-)) and atropinized group (0.015 mg.kg(-1) i.m., n = 23; A(+)). Control hemodynamics were measured under 0.5% halothane and 67% nitrous oxide and 33% oxygen for three minutes, and then halothane was increased to 2.5% and maintained for 15 min. In the A(-) group, stroke volume (SV) decreased to 64%, heart rate (HR) increased from 100/min to 111/min, and blood pressure (BP) decreased from 65 mmHg to 62 mmHg. Skin blood flow (SBF) concomitantly measured by a laser doppler flowmeter decreased to 48% and total peripheral resistance (TPR) increased to 128%. In the A(+) group, HR increased from 117/min to 132/min ( P < 0.05, vs. A(-) group), BP decreased from 67 mmHg to 66 mmHg. SV decreased to 71% ( P < 0.05, vs. A(-) group). Changes in SBF and TPR were 68% and 128% respectively. End-expired halothane concentration in the A(+) group increased slower than in the A(-) group but not significantly. The results indicate increased sympathetic tone would work as a compensating mechanism for decreased SV and CO. Atropine premedication attenuated cardiovascular depression by maintaining HR and possibly by delaying induction speed of anesthesia. In conclusion, halotane-nitrous oxide anesthesia decreased SV without a marked decrease in heart rate and blood pressure in children. This decrease in SV and BP was attenuated by atropine premedication.

Clinical Trial↗
PubMed1992

Competitive and non-competitive N-methyl-D-aspartate antagonists fail to prevent the induction of methamphetamine-induced sensitization.

In order to elucidate the possible roles of the glutamate system in the mechanisms underlying behavioral sensitization, which is used as an animal model for human psychosis, we investigated the effects of 3-((+/-)-2-carboxypiperazin-4-yl)propyl-1-phosphonic acid (CPP) and MK-801 ((+)-dizocilpine), a competitive and noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist, respectively, on methamphetamine-induced behavioral sensitization in rats. Administration of 0.5 mg/kg MK-801 enhanced 2 mg/kg methamphetamine-induced hyperactivity, whereas it reduced 6 mg/kg methamphetamine-induced stereotyped behavior markedly. CPP (10 mg/kg) reduced 2 mg/kg methamphetamine-induced stereotypy slightly. Repeated treatment with 2 and 6 mg/kg methamphetamine alone induced progressive augmentation of stereotypy, whereas combining either MK-801 or CPP with methamphetamine treatment abolished or attenuated this augmentation. However, when rats were challenged with methamphetamine after a 7-day period of abstinence, the intensity of stereotypy among the rats pretreated with repeated doses of methamphetamine alone or in combination with MK-801 or CPP did not differ significantly. These results indicate that competitive and non-competitive NMDA receptor antagonists modulate acute methamphetamine-induced abnormal behavior and sensitization expression, but they failed to prevent the induction of the neural mechanisms underlying behavioral sensitization.

Animals↗
PubMed1992

Modified polytetrafluoroethylene: indium 111-labeled platelet deposition on carbon-lined and high-porosity polytetrafluoroethylene grafts.

Platelet accumulation on carbon-lined (CL) and high-porosity (HP) polytetrafluoroethylene (PTFE) grafts was investigated in vivo. In experiment 1, 20 CL grafts and 20 control PTFE grafts, each 5 cm in length and 4 mm in diameter, were interposed into both carotid and femoral arteries of 10 dogs. In experiment 2, 12 HP grafts (90 microns mean internodal distance) and 12 control PTFE grafts were implanted in six dogs. Indium 111-labeled platelets were injected intravenously and the grafts were retrieved 48 hours later. Radioactivity of the grafts and a control segment of the carotid artery was counted. A graft platelet accumulation index (GPAI) was calculated as the ratio of emission from the graft compared to that from the control segment. The GPAI of the CL graft was significantly less than the GPAI of the control graft in both the carotid (control 29.7 +/- 5.46, CL 22.3 +/- 6.55; n = 9 [p < 0.05]) and the femoral arteries (control 30.7 +/- 9.65, CL 22.0 +/- 6.59; n = 9 [p < 0.05]). There was no significant difference in GPAI between the control and HP grafts in the carotid arteries (control 30.6 +/- 11.8, HP 31.5 +/- 9.71; n = 6) and in the femoral arteries (control 31.5 +/- 7.88, HP 34.0 +/- 4.97; n = 6). Carbon lining decreases platelet accumulation on PTFE grafts in the early postoperative period, and HP grafts do not exhibit increased platelet uptake.

Animals↗
PubMed1992

Changes in ventilatory pattern and arterial oxygen saturation during spinal anaesthesia in man.

Using a respiratory inductive plethysmograph and a pulse oximeter, we investigated the changes in the respiratory pattern and peripheral oxygen saturation (SpO2) of the finger before and during spinal anaesthesia in 20 surgical patients. The rib cage contribution to the tidal volume (%RC) increased significantly from before (20.4 +/- 4.3%) to during spinal anaesthesia (30.4 +/- 4.8%). However, in those patients who fell asleep 60 min after subarachnoid injection of a local anaesthetic, %RC returned to the preanaesthetic value (23.0 +/- 5.9%). Finger SpO2 increased significantly during spinal anaesthesia, but the femoral arterial oxygen saturation did not change. The authors conclude that spinal anaesthesia increases %RC in conscious patients. However, the increment of %RC does not cause a major change in arterial oxygen saturation.

Adult↗
PubMed1992

[Hemodilutional and blood salvaging autotransfusions in a case of aplastic anemia].

A 28-year-old female, weighing 46 kg, 155 cm in height, with aplastic anemia underwent implantation of iliac bone to the head of the femur. A combined technique of hemodilution and intraoperative blood salvaging was applied to supplement the blood loss during the operation. Intraoperative monitoring included continuous arterial pressure, heart rate, electrocardiograph, SVO2, bleeding time, prothrombin time (PT), activated thromboplastin time (APTT), and thromboelastography. A total of 900 ml of blood was drawn and the same volume of 5% albumin solution was infused over half an hour before the beginning of the surgery. During the operation, 2100 ml of blood was lost, and 1260 ml of autologous blood, 400 ml of homogeneous red blood cells and 5 units of fresh platelet were infused. The values of PT, APTT, bleeding time were within normal ranges after the surgery. Only 3 units of fresh platelet was infused in 2 weeks after the surgery. It was suggested that hemodilution and salvaging autotransfusion is safely performed and beneficial to minimize homogeneous blood transfusion even in a case of aplastic anemia.

Adult↗
PubMed1991

Difference in the effect of pancuronium and vecuronium on baroreflex control of heart rate in humans.

The effects of pancuronium and vecuronium, each in doses of 0.05 and 0.08 mg.kg(-1), on the baroreflex control of the heart rate were studied in 40 adult patients of either sex (21 men and 19 women) during stable nitrous oxide-oxygen-fentanyl anesthesia. The blood pressure was elevated by intravenous infusion of phenylephrine (4 micro g.kg(-1).min(-1)) for the pressor test, and lowered by a bolus injection of nitroglycerin (0.3-0.5 mg) for the depressor test. Baroreflex sensitivity was judged from the slope of the regression of the systolic blood pressure on the succeeding R-R intervals on the ECG. There was no significant difference between the baseline blood pressure at which both tests were carried out. Nitrous oxide-oxygen-fentanyl anesthesia alone suppressed the baroreflex sensitivity to a level which was at the lower limit of the physiological and non-anesthetized state. The 0.08 mg.kg(-1) dose of pancuronium significantly suppressed the reflex sensitivity in both the pressor and depressor tests. However, the 0.05 mg.kg(-1) dose of pancuronium and both doses of vecuronium did not cause any significant change in the test results.

Journal Article↗
PubMed1991

CO2 laser-assisted microvascular anastomosis: biomechanical studies and clinical applications.

Experiments have been performed using CO2 laser-assisted microvascular anastomoses, and they demonstrated the following features, in comparison with conventional anastomoses: ease in technique; less time consumption; less tissue inflammation; early wound healing; equivalency of patency rate and inner pressure tolerance; but only about 50 percent of the tensile strength of manual-suture anastomosis. Six clinical applications in 16 vessels are reported, using this procedure. The preliminary results of these cases would appear to be the first successful replantations and free tissue transfers using CO2 laser-assisted microvascular anastomoses in man. The procedure offers increased safety and speed in microvascular anastomoses.

Adolescent↗
PubMed1991

Study of lupus nephritis in males.

Clinical and pathological findings were studied in 23 male patients with lupus nephritis who were followed up for a period of 41 +/- 36 months after renal biopsy. Age at renal biopsy was 31 +/- 14 years and 19 patients (83 per cent) were between 15 and 50 years old. C3 and C4 levels were below normal in 23 (100 per cent) and 16 (70 per cent) respectively, CH50 was less than 25 u/ml in 67 per cent, and antinuclear and anti-DNA antibodies were found in 87 per cent and 82 per cent respectively. Serum albumin level increased from 2.9 +/- 0.8 g/dl to 3.7 +/- 0.8 g/dl during the follow up period (p less than 0.01), while urinary protein decreased from 2.0 +/- 2.3 g/day to 1.4 +/- 2.5 g/day. There was a significant improvement in the degree of haematuria (p less than 0.01), but serum creatinine levels showed no change (mean 1.5 mg/ml). Active proliferative lupus nephritis of moderate or severe degree was observed in 65 per cent of patients at the initial biopsy. A trend to regression in this activity was seen in most serial biopsies, but the chronicity index showed a slight increase. These data demonstrate that systemic lupus erythematosus in males, in comparison to our previous report of the disease in female patients, is accompanied by more active nephritis, but that it follows a benign course with therapy.

Adolescent↗
PubMed1991

Effects of thoracic epidural anesthesia on myocardial pH and metabolism during ischemia.

The effect of thoracic epidural anesthesia (TEA) on the ischemic myocardium was examined in open-chest dogs anesthetized intravenously. Ischemia induced by brief coronary artery occlusion caused an elevation of the ST segment in epicardial ECG and a reduction in myocardial pH and contractile force. TEA with 0.15 ml/kg of 0.4% bupivacaine solution attenuated an ischemia-induced decrease in myocardial pH and an increase of the ST segment in epicardial ECG. This attenuation was maintained even after the restoration of blood pressure and heart rate, which had been decreased significantly after TEA, to pre-TEA levels, suggesting that a beneficial effect of TEA should not be confined to its hemodynamic changes such as decreased blood pressure and heart rate. In contrast, the subendocardial contents of ATP, creatine phosphate (CP) and lactate were not affected by TEA, either in the presence or the absence of 5 min LAD occlusion. These results suggest that neither hemodynamic nor metabolic changes are responsible for the reduced myocardial ischemic acidosis induced by TEA after brief coronary artery occlusion. The acidosis-saving property of TEA is favorable for the ischemic heart.

Adenosine Triphosphate↗
PubMed1991

In vivo study of an elastomer end-coated polytetrafluoroethylene vascular prosthesis.

Polyurethane end-coated polytetrafluoroethylene (PTFE) grafts (elastomer PTFE grafts) were implanted in 12 female adult mongrel dogs to assess patency, intimalization, tissue incorporation, and technical suitability of the material as a vascular graft. Each dog had bilateral aortoiliac grafts placed, one a standard PTFE and the other an elastomer PTFE graft. The length of the grafts was 7-8 cm and the diameter was 6 mm. The grafts were harvested at intervals to 120 days postoperatively. The elastomer PTFE grafts showed superior longitudinal elasticity, retention of shape, and no graft tearing with suture tension; however, no significant difference in bleeding was noted at the anastomoses between the standard and elastomer PTFE grafts. Satisfactory patency was obtained with both standard (8/10) and elastomer PTFE grafts (9/10) at 90-120 days. No significant difference in the thickness of intima and the length of pannus ingrowth was noted between the standard and elastomer PTFE grafts. No outer tissue incorporation was seen at the elastomer-treated graft segments as opposed to the well-incorporated untreated segments. In conclusion, elastomer end-coating of a PTFE vascular prosthesis provided excellent handling characteristics without detracting from patency; however, the lack of outer tissue incorporation may be a potential disadvantage in its clinical use.

Anastomosis, Surgical↗
PubMed1991

[The effects of nicardipine and verapamil on the recovery time of vecuronium-induced neuromuscular blockade].

The present study investigated the effects of intravenous therapeutic dose of either nicardipine or verapamil on the recovery from transient neuromuscular blockade produced by vecuronium in 21 adult patients scheduled for elective surgery. Neuromuscular function was evaluated by single twitch height (T1), an amplitude of activity of the ulnar nerve being evoked by an electrical stimulation (0.2 msec, 0.1 Hz) under N2O/O2 and halothane anesthesia. The patients given vecuronium were randomly assigned to one of 3 groups: a control group who received no Ca entry blocker, nicardipine group and verapamil group. Nicardipine (30 mcg.kg-1) or verapamil (50 mcg.kg-1) was injected when T1 reached to 10% of the control twitch height. The recovery time of vecuronium (the time between 25% and 75% recovery) was not different significantly among the control (9.4 +/- 3.7 min), nicardipine (8.5 +/- 3.1 min) and verapamil (9.8 +/- 4.3 min) groups. We conclude that a therapeutic dose of either nicardipine or verapamil could be safely given intravenously to the patients under vecuronium-induced neuromuscular blockade.

Adult↗
PubMed1990

Tubulointerstitial changes in systemic vasculitic disorders: a quantitative study of 18 biopsy cases.

Tubulointerstitial alterations were studied in 18 biopsy cases of systemic vasculitis. To evaluate the changes more objectively, two indexes, the number of interstitial inflammatory cells and tubulitis percentage, were used. The group means of both of these indexes were statistically higher than those of the autopsy control group, while 14 of the cases (77.8%) showed a significant difference (P less than 0.01) between individual means and the control group means. On the other hand, tubulointerstitial changes in systemic vasculitis seemed to be less prominent than drug-induced tubulointerstitial nephritis (TIN) according to these indexes. However, comparing these indexes with those of drug-induced TIN, six cases (33.3%) of systemic angiitis could be regarded as having developed pathologic changes similar to TIN. Statistical difference was not shown in the indexes between those patients with histologic evidence of necrotizing angiitis and those without it. Clinically, urinary N-acetyl-beta-D-glucosaminidase (NAG) was abnormally high in all three examined cases, reflecting the damage of renal tubular epithelial cells. Not only the vascular and glomerular lesions, but also tubulointerstitial changes, should be evaluated in the renal biopsy specimen of systemic vasculitis.

Adult↗