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Biomedical subjects

M Kuro

Publications and source records attributed to M Kuro.

At least 55 records · Page 3Linked to original sources
PubMed1997

[Regional cerebral hypoperfusion reduces the effect of rectal midazolam in children with Moyamoya disease].

To investigate the effect of regional cerebral blood flow on the effect of midazolam, we evaluated 99mTc-hexamethylpropylene-amine-oxime-single photon emission computed tomography (SPECT) in 37 cases of childhood moyamoya disease. They were divided into two groups according to the findings of SPECT; one group showed hypoperfusion in the bifrontal regions (n = 20), and the other did not (n = 17). Both groups received 1 mg.kg-1 of midazolam transrectally 30 min before the anesthesia induction and level of sedation was measured with six point scales. Significantly lower level of sedation score was recognized in the group that showed hypoperfusion in bifrontal regions (P < 0.05). Our finding may suggest that regional cerebral hypoperfusion may modify the sedative effect of midazolam in children with moyamoya disease.

Administration, Rectal↗
PubMed1996

[The efficacy of transesophageal echocardiography during the pericardial drainage of the cardiac tamponade after cardiac surgery].

For two cases of cardiac tamponade following cardiac surgery, the approaches for pericardial drainage were determined by the transesophageal echocardiography under general anesthesia. In most cases of cardiac tamponade after cardiac surgery the pericardial effusion is regional and localized due to adhesions of pericardium. Therefore subxiphoid incision approach of pericardial drainage cannot often be accomplished. In these cases transesophageal echocardiography can image the presence, location and size of the pericardial effusion and is an available method to determine the approach of pericardial drainage.

Aged↗
PubMed1996

[Comparison of cerebral oxygen metabolism during normothermic versus moderate hypothermic cardiopulmonary bypass].

We compared the effects of normothermic (NCPB, N = 5) and moderate hypothermic (HCPB, (N = 5) cardiopulmonary bypass on cerebral oxygen metabolism in patients undergoing coronary artery bypass grafting. For monitoring of cerebral oxygenation, we used jugular venous oxyhemoglobin saturation (SjVO2) and near infrared spectroscopy (NIR). In NCPB group, although SjVO2 decreased temporally at the start of cardiopulmonary bypass, it became stabilized above 50% during the rest of cardiopulmonary bypass. In HCPB group, on the contrary, oxyhemoglobin measured by NIR showed maximum decrease during rewarming under cardiopulmonary bypass. Furthermore, SjVO2 decreased under 50% at the end of cardiopulmonary bypass (3/5 cases). We consider that NCPB is a useful technique for preventing cerebral hypoxia, if the decrease of SjVO2 during the early period of cardiopulmonary bypass is avoidable. Lastly, we also advocate that both SjVO2 and NIR are useful monitoring systems for continuous evaluation of cerebral oxygen metabolism during cardiopulmonary bypass.

Brain↗
PubMed1996

[Anesthetic management for AICD (automatic implantable cardioverter defibrillator) implant surgery].

We studied anesthetic management and monitoring during AICD (automatic implantable cardioverter defibrillator) implantation. For anesthetic management, complete sedation and amnesia are needed during implantation procedures with rapid awakening and extubation after the surgery. We chose inhalation anesthesia supplemented with small doses of fentanyl or thiamylal. Monitoring for AICD implantation should be less invasive, continuous and rapid in responsiveness. For brain and cardiac monitoring, a combination of near infrared spectroscopy and transesophageal echocardiography was quite useful.

Anesthesia, General↗
PubMed1996

[Cardiac surgery using cardiopulmonary bypass in a patient with sickle-cell trait].

The sickle-cell gene is most concentrated in West Central Africa, the northeast corner of Saudi Arabia and East Central India. Sickle cell trait is the heterozygous condition for Hb S gene. Thirty to fifty per cent of their hemoglobin is Hb S and the remainder is Hb A. The sickle-cell crisis is induced by hypoxia, hypercarbia, acidosis, low flow condition, and hypothermia, which leads to vasoocclusion. A 39-year-old black man from Burkina Faso located in West Africa with left ventricular rupture was admitted for operation using cardiopulmonary bypass (CPB). He had been diagnosed as sickle-cell trait. The Hb S concentration was 36.2 per cent before operation with hemoglobin electrophoresis. During CPB, the minimum blood temperature was 31 degrees C and an aortic cross-clamp was not done. Total CPB time was 1 hour 31 minutes. Use of vasodilator and hyperventilation was effective. No neurological sequelae were observed.

Adult↗
PubMed1996

[Aortic dissection after weaning from extracorporeal circulation].

Acute aortic dissection is a rare complication of cardiac surgery. But once it happens, its outcome is often miserable. We experienced this complication after discontinuing cardiopulmonary bypass (CPB). A 56-year old man with mitral regurgitation was referred for mitral valve replacement under CPB. After weaning from extracorporeal circulation (ECC), the right radial artery pressure decreased suddenly and its waveform became flat. After 5 minutes, dissection of the ascending aorta was diagnosed by transesophageal echocardiography (TEE). We started to prevent ischemic brain damage immediately, but a severe brain damage occurred. Its early diagnosis is necessary and the prevention of critical brain damage due to low perfusion of the blood is important for anesthetic management.

Aortic Dissection↗
PubMed1996

[Brain monitoring with near infrared spectroscopy during carotid endarterectomy].

We evaluated clinical efficacy of near infrared spectroscopy (NIR) as a monitoring system for cerebral oxygenation during anesthesia for carotid artery endarterectomy. NIR proved to be affected significantly by clamping of the external carotid artery. The present study suggests that this monitoring system may be useful for evaluation of cerebral blood flow following declamping of the internal carotid artery, although it has some limitations during clamping of the artery.

Aged↗
PubMed1995

Optimal placement of CVP catheter in paediatric cardiac patients.

For correct monitoring of central venous pressure (CVP) the tip of the CVP catheter should be placed in the superior vena cava (SVC). Since there is no useful guide for the optimal depth of insertion of CVP catheter in children undergoing cardiovascular surgery, we examined the relationship between the depth of the CVP catheter and easily measured body-size variables, such as age, weight and height, and then created a guide for the optimal placement of the paediatric population. The CVP catheterization was performed through the right internal jugular vein by the high approach. The position of the catheter tip was determined by the wave form of the CVP tracing and the depth of insertion was assessed by the external marking on the catheter at the cannulation site. The position of the catheter tip, determined by postoperative AP chest x-ray, was identified by the level of thoracic vertebra (T) corresponding to the position of the catheter tip. We analyzed the relationship between the depth of the catheter and patient's age, weight and height by linear regression analysis. The position of tip was normally distributed from T1 to T7 and the tips were centralized at levels of T3, T4 and T5 which anatomically correspond to SVC. The r values between the catheter depth and the three factors at each level were comparable, although the correlation between the depth of catheter and height was best. A simple guide for placement of the catheter tip at T3, T4 and T5 levels as a function of patient's height was created.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Surgical Procedures↗
PubMed1995

[Usefulness of monitoring with near infrared spectroscopy during retrograde cerebral perfusion].

Recently retrograde cerebral perfusion (RCP), a newly developed technique for cerebral protection during surgical replacement for thoracic aortic aneurysm, has been used in many institutes. However, there is no established monitoring methods for cerebral oxygenation during this procedure. In the present study, we examined if near infrared spectroscopy (NIR) is useful for monitoring cerebral oxygenation during RCP. We studied 7 patients undergoing operations for aneurysms of the ascending aorta and transverse arch in the supine position (Group A) and another seven patients undergoing operations for aneurysms of the transverse arch and descending aorta in the lateral decubitus position (Group D) in this study and monitored cerebral oxygenation with NIR. NIR showed a slow but continuous decrease in oxygenated hemoglobin and an increase in deoxygenated hemoglobin during RCP, while these changes disappeared following the termination of RCP. The degree of these changes in Group D was significantly greater than that in Group A. In comparison, we observed rapid reduction of oxygenated hemoglobin during the period of circulatory arrest and low perfusion pressure with NIR, suggesting the usefulness of RCP for cerebral oxygenation. NIR may be a useful method of monitoring cerebral oxygenation during RCP.

Aged↗
PubMed1995

[Anesthetic management using percutaneous cardiopulmonary support for cesarean section in a patient with severe pulmonary hypertension].

A 27-year-old female with severe pulmonary hypertension was scheduled to undergo an elective cesarean section at the 32-week gestational age. Since the preoperative assessment revealed that the patient could not tolerate the hemodynamic changes during the operation under general anesthesia without any cardiopulmonary support, the percutaneous cardiopulmonary support (PCPS) with a centrifugal pump was applied for the anesthetic management of the patient during the operation. After the induction of anesthesia, percutaneous cannulation was performed via the femoral artery and vein, and the PCPS was started with an assisted flow ranged 1.5-2.0 l.min-1. Then, the operation was performed, during which the cardiopulmonary function of the patient was well maintained with the aid of the PCPS. The operation was finished uneventfully, and the patient could successfully emerge from the PCPS immediately after the operation. The PCPS is thought to be very useful for the anesthetic management of the patients with poor cardiopulmonary tolerance.

Adult↗
PubMed1995

[Relationship between retained microbubbles and neuropsychologic alterations after cardiac operation].

We studied the relationship between quantity of microbubble retained in the left heart and neuropsychologic alterations after surgery in 21 patients undergoing cardiac surgery including cardiopulmonary bypass. The neuropsychologic change was evaluated by three kinds of psychological test, which mainly analyzed memory and cognition. The microbubble was continuously monitored by the long axis view of the descending aorta of transesophageal echocardiography and then quantitatively analyzed and graded by the on-line computer. More microbubbles were detected in the valve surgery requiring the intracardiac procedure than in coronary artery bypass grafting and neuropsychologic deterioration, although the relationship did not reach statistical significance. Since most of the microbubbles were detected during the unclamping of aorta and the weaning from cardiopulmonary bypass, a technical improvement of the surgical procedures could reduce them. We think that transesophageal echocardiography is useful for monitoring microbubbles during operation.

Adult↗
PubMed1994

Internal jugular bulb blood velocity as a continuous indicator of cerebral blood flow during open heart surgery.

BACKGROUND: Most techniques for measuring cerebral blood flow (CBF) can not be performed rapidly enough to detect sudden changes in CBF. However, measurement of internal jugular bulb (IJB) blood velocity may offer real-time information on changes in CBF. In the current study, we measured IJB blood velocity and CBF in anesthetized humans. METHODS: In protocol 1, IJB blood velocity was continuously measured using an intravascular Doppler catheter during cardiac surgery under hypothermic cardiopulmonary bypass (CPB). CBF values obtained with a Kety-Schmidt method using inhalation of 30% argon in oxygen gas were compared with concurrent IJB blood velocity values in ten patients. A 3-French intravascular Doppler catheter was placed in the right IJB, and CBF measurements were made before CPB, in a stable hypothermic period during CPB, at rewarming during CPB, and after CPB. In protocol 2, dimensions of right IJB were observed before and during CPB using an intravascular rotating A scan ultrasonic catheter (5-French) in three patients. RESULTS: IJB blood velocity responded quickly to changes in arterial pressure or body temperature during CPB. The percent change in IJB blood velocity relative to pre-CPB value showed a good linear correlation with the percent change in CBF (%CBF = 0.87 x %IJB velocity + 17, r = 0.87). The mean difference between percent changes in CBF and IJB blood velocity was -5.6% and the standard deviation was 16%. Despite a large reduction in arterial pressure or IJB pressure, there were no significant changes in the IJB dimension. CONCLUSIONS: The results suggest that IJB blood velocity may represent a clinically useful monitor of changes in CBF in anesthetized humans.

Aged↗
PubMed1994

[Anesthetic management and neurological outcomes of patient for open heart surgery with infective endocarditis and neurological complications].

No reports have focused on neurological outcomes after open heart surgery of patients with infective endocarditis (IE) and neurological complications. We evaluated parameters related to anesthetic management and neurological outcomes. The subjects analyzed were 24 patients who had undergone valvular surgeries under hypothermic cardiopulmonary bypass from April 1978 to December 1990. The patients were divided into two groups according to the interval between onset of neurological complication and the time of operation: 1) acute group (within one month before the surgery: n = 11, 9.4 +/- 9 days; means +/- SD) and 2) chronic group (more than one month before the surgery: n = 13, 120 +/- 80 days). After heart surgery, 5 patients in the acute group showed newly developed neurological abnormality including death from hemorrhagic transformation, hemiplegia or aphasia. No patients in the chronic group had newly developed neurological abnormality related to the surgery. In the neurologically deteriorated patients of the acute group, interval from the onset of neurological complication to surgery was 3.5 +/- 4.5 days, whereas that of the remainders of the acute group was significantly longer (14.4 +/- 9.0 days). Intraoperative events and anesthetic management of these patients were also analyzed. However, there were no significant differences in the parameters such as cerebral perfusion pressure, arterial PaCO2, doses of anesthetics and use of vasopressors. Our results suggest that the most important factor which may influence neurological outcome was the interval between the onset of neurological abnormality and the time of operation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Role of imidazoline-preferring receptors in the genesis of epinephrine-induced arrhythmias in halothane-anesthetized dogs.

BACKGROUND: Drugs with a central alpha 2-adrenergic action can increase the threshold for halothane-epinephrine-induced arrhythmias. Recently, imidazoline-preferring receptors were shown to play a significant role in the hypotensive effect of alpha 2-adrenergic agonists containing an imidazole ring in their structure. To address the question of whether the antiarrhythmic property of the alpha 2-adrenergic agonists was caused by activation of alpha 2-adrenoceptors or imidazoline-preferring receptors in the central nervous system, the effect of an imidazoline (atipamezole) and a nonimidazoline (L-659,066 and yohimbine) alpha 2-adrenergic antagonist were examined as etiologic factors in the genesis of halothane-epinephrine-induced arrhythmias in dogs. METHODS: Adult mongrel dogs were anesthetized with halothane (1.3%) and monitored continuously for systemic arterial pressure and for premature ventricular contractions. The arrhythmogenic dose (AD) of epinephrine, defined as the smallest dose producing four or more premature ventricular contractions within a 15-s period, was determined in the presence of atipamezole (an imidazoline compound that acrosses the blood-brain barrier), L-659,066 (a nonimidazoline compound that does not penetrate the blood-brain barrier), and yohimbine (a nonimidazoline compound that passes the blood-brain barrier). These drugs were administered either intravenously or into the cisterna magna to assess the site of action for changes in responsiveness. RESULTS: Intravenous atipamezole decreased the AD of epinephrine in the dose-dependent fashion. However, neither L-659,066 nor yohimbine, administered peripherally, decreased the AD of epinephrine. Central administration of atipamezole also decreased the AD of epinephrine, while L-659,066, even if administered centrally, did not affect the AD of epinephrine in the presence of halothane. CONCLUSIONS: Because the imidazoline ring-containing alpha 2-adrenergic antagonist (atipamezole) potentiated the halothane-epinephrine-induced arrhythmias and the nonimidazole alpha 2-adrenergic antagonist (L-659,066 and yohimbine) did not, it is possible that the imidazoline-preferring, rather than the alpha 2-adrenergic, receptor is responsible for the antiarrhythmic property of alpha 2-adrenergic agonists.

Adrenergic alpha-Antagonists↗
PubMed1993

Effects of sevoflurane on cerebral circulation and metabolism in patients with ischemic cerebrovascular disease.

BACKGROUND: Sevoflurane is a newly developed volatile anesthetic that has a low blood-gas partition coefficient. The effects of sevoflurane on the cerebral circulation or metabolism in humans have not been studied. The authors examined the cerebral blood flow (CBF) and cerebral metabolic rate for oxygen (CMRO2) during sevoflurane anesthesia. The carbon dioxide response and autoregulation of cerebral circulation were also examined. METHODS: Ten patients with ischemic cerebrovascular disease undergoing extra-intracranial artery anastomosis were studied. Cerebral blood flow and CMRO2 were determined by the Kety-Schmidt method using argon. These procedures were performed during the inhalation of 33% N2O, 33% argon, and oxygen with 1.5% sevoflurane (0.88 minimum alveolar concentration). To examine the relationship of CBF to a change in PaCO2, CBF was measured repeatedly at steady state PaCO2, of 40, 35, and 45 mmHg. Furthermore, CBF was measured before and after an increase in mean arterial pressure (MAP) caused by intravenous infusion of methoxamine to determine the relationship between CBF and MAP. RESULTS: Cerebral blood flow and CMRO2 were 28 +/- 4 ml x 100 g-1 x min-1 and 1.34 +/- 0.23 ml x 100 g-1 x min-1, respectively. Cerebral blood flow was found to vary directly with PaCO2 alteration. The slope of the regression line between PaCO2 and CBF was 1.29 ml x 100 g-1 x min-1 x mmHg-1. On the other hand, CBF was constant throughout the elevation of MAP with vasopressor. CONCLUSIONS: Both carbon dioxide response and cerebral autoregulation were well maintained under 0.88 MAC sevoflurane anesthesia in patients with ischemic cerebrovascular disease.

Adult↗
PubMed1993

Intra-operative monitoring of cerebral haemodynamics in a patient with Takayasu's arteritis.

Transcranial Doppler and continuous measurements of jugular venous oxygen saturation were used to monitor intra-operative cerebral haemodynamics in a patient with Takayasu's arteritis who underwent carotid revascularisation. These techniques were found to be of clinical value for detection of cerebral hypoperfusion and assessment of the effects of therapeutic intervention.

Adult↗