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Biomedical subjects

T Murakawa

Publications and source records attributed to T Murakawa.

At least 73 records · Page 4Linked to original sources
PubMed1991

Familial occurrence of arteriovenous malformation of the brain.

Brain arteriovenous malformations are considered to originate from a congenital maldevelopment of the brain vessels. Although there have been occasional reports suggesting a familial incidence of these lesions, data for only 10 families have been accumulated in the literature. The authors report on six such cases in three families. This high rate of occurrence of familial cases suggests an involvement of genetic factors.

Adolescent↗
PubMed1991

[Survey of cardiac arrests during and following anesthesia and surgery for the past seven years].

Cardiac arrests, excluding those associated with cardiac surgery, occurred in eleven out of 13,278 patients who had general anesthesia in our hospital for seven years from 1983 to 1989. Four of them were successfully resuscitated, while the remaining seven patients were lost. The causes of these cardiac arrests were as follows: massive bleeding in four; cardiac compression by surgeons in two; possible coronary artery spasm in one; hyperpotassemia in one; severe metabolic acidosis in one; myocardial ischemia in one; and unknown cardiogenic origin in one. There is no case in which anesthesia was the primary cause of cardiac arrest. Although we can not be absolutely free from cardiac arrest during anesthesia and surgery, we should do our best to detect and correct any factors leading to perioperative cardiac arrests.

Anesthesia, General↗
PubMed1991

[Plasma alpha-human atrial natriuretic polypeptide levels during surgery for pheochromocytoma].

We measured plasma alpha-human atrial natriuretic polypeptide (alpha-hANP) and catecholamine concentrations during anesthesia and surgery for pheochromocytoma in five patients ranging in ages from 19 to 69. Plasma catecholamine concentrations and systemic blood pressure increased extremely during surgical manipulation of the tumor, while plasma alpha-hANP levels did not change even during surgical manipulation or after removal of the tumor as compared with preanesthetic values. Our findings suggest that plasma alpha-hANP levels were unchanged during anesthesia and surgery for human pheochromocytoma.

Adrenal Gland Neoplasms↗
PubMed1991

[Clinical study on total intravenous anesthesia with droperidol, fentanyl, and ketamine--6. Effects on postoperative liver function].

We have developed a new method of total intravenous anesthesia with droperidol, fentanyl, and ketamine, and have administered it to more than 700 surgical patients. We studied whether this method of anesthesia would influence postoperative liver function or not. A total of sixty elective surgical patients were the subjects of this study. Thirty patients underwent total hysterectomy under either the total intravenous anesthesia (15 patients) or modified neurolept-anesthesia with pentazocine (15 patients). The remaining 30 patients underwent gastrectomy under either this total intravenous anesthesia (15 patients) or enflurane-N2O anesthesia (15 patients). The hepatic function was evaluated as judged by s-GOT, s-GPT, ALP, gamma-GPT and total bilirubin levels, before anesthesia and during the first to third postoperative day. The patients for gastrectomy under enflurane-N2O anesthesia had significantly increased postoperative gamma-GPT levels compared with the patients of total intravenous anesthesia. Any other variables showed no significant difference among groups. We consider that this method of total intravenous anesthesia has no adverse effects on postoperative liver function as compared with other usual anesthetic methods.

Anesthesia, Inhalation↗
PubMed1990

[Effect of continuous epidural infusion of morphine on postoperative glucose metabolism].

Plasma growth hormone (GH), insulin, prolactin and blood glucose levels were measured to evaluate postoperative pain relief either with epidural morphine or systemic analgesics in 16 patients who underwent gastrectomy. Continuous epidural morphine with a pump (CADD-PCA, Model 5200P, Pharmacia) was given to eight (epidural morphine group) patients. A bolus of epidural morphine was administered through an indwelling thoracic (Th8.9) catheter at 3 hrs prior to the expected end of surgery, which was followed with continuous epidural infusion of morphine at a rate of 0.167-0.042 mg.hr-1 with the pump during and after anesthesia and surgery with gradually decreasing dose until the third postoperative day. The remaining eight patients (systemic analgesics group) repeatedly received intravenous or intramuscular pentazocine and buprenorphine when needed. Plasma GH levels increased significantly only on the first postoperative day in both groups. Plasma insulin levels increased significantly on the first postoperative day in both groups. Blood glucose levels increased significantly at the end of surgery and during the following three postoperative days in both groups. There are no statistical differences in plasma GH, insulin and blood glucose levels between the two groups. Plasma prolactin concentrations increased significantly at the end of surgery and they were significantly higher in the systemic analgesic group than in the epidural morphine group. They, however, returned to the previous day's levels on the first postoperative day in both groups. Our study suggests that continuous epidural infusion of morphine has no suppressing effect on postoperative changes in plasma GH, insulin, prolactin and blood glucose levels as compared with systemic analgesic regimen.

Adult↗
PubMed1990

Extracellular magnesium and potassium concentrations interact to modulate tone and reactivity of isolated canine cerebral vascular muscle.

In vitro studies were undertaken to investigate the effects of external potassium [K+]o, 0-7.1 mM, and magnesium [Mg2+]o, 0-4.8 mM, concentration on canine middle cerebral and basilar arterial basal tone and on 5-hydroxytryptamine (5-HT)-induced contractions. The lower the [K+]o, the greater the degree of spontaneous contraction upon acute withdrawal of [Mg2+]o. An inverse linear relationship between the concentration of [K+]o and the degree of cerebrovasospasm upon acute withdrawal of [Mg2+]o was observed over the range of 1-6 mM [K+]o. As [K+]o was increased, stepwise, the slow phase of the contractions became attenuated, while the magnitude of the fast phase became progressively smaller. Acute withdrawal of [K+]o produced contraction of middle cerebral and basilar arteries which could be modulated by the concentration of [Mg2+]o. The higher the [Mg2+]o, the less the tension developed upon acute withdrawal of [K+]o. Contractility to 5-HT was depressed when [K+]o was lowered. This attenuation was reversed completely when [Mg2+]o was acutely withdrawn. Sensitivity (EC50) of canine middle cerebral and basilar arteries to 5-HT was inversely related to the [K+]o/[Mg2+]o ratio. These actions took place over pathophysiological ranges of [K+]o and [Mg2+]o. Maintenance of a constant [K+]o/[Mg2+]o ratio, irrespective of the exact [K+]o and [Mg2+]o, produced similar degrees of maximum tension and sensitivity (EC50) to 5-HT. Use of intact ring preparations and helically cut vascular strips produced similar results with varying [K+]o/[Mg2+]o. A variety of pharmacological receptor antagonists (phentolamine, propranolol, atropine, diphenhydramine, cimetidine), as well as a prostaglandin cyclo-oxygenase inhibitor, did not modify the altered contractile responses or basal tone evoked by varying the [K+]o/[Mg2+]o ratios. These experiments suggest: (1) that basal tone and contractility of canine cerebral vascular smooth muscle cells appear to be exquisitely sensitive to alterations in extracellular K+ and Mg2+ and (2) that 5-HT receptor-operated Ca2+ channels, as well as those Ca2+ channels involved in the generation of cerebral arterial basal tone, are modulated and controlled by the precise concentrations of [K+]o and [Mg2+]o.

Animals↗
PubMed1990

[Clinical study on total intravenous anesthesia with droperidol, fentanyl and ketamine--1. Introduction].

We have developed a new method of total intravenous anesthesia with droperidol, fentanyl and ketamine and have administered it to more than 400 surgical patients, ranging in ages from 4 to 80 years. Cardiac and neurosurgical patients were excluded. After establishing a routine monitoring, droperidol 0.06-0.1 ml.kg-1 was slowly given. After 5 minutes, fentanyl 1-2 micrograms.kg-1 and ketamine 1.0-1.5 mg.kg-1 were slowly administered intravenously. Trachea was intubated following intravenous succinylcholine. A total dose of 5-15 micrograms.kg-1 of fentanyl was given intravenously with a continuous infusion of ketamine 2 mg.kg-1.hr-1 during surgical procedure. Air and O2 (FIO2 0.30-0.35) were given and muscle relaxation was achieved with necessary dose of intravenous pancuronium or vecuronium and no inhaled anesthetic was given. Total intravenous anesthesia has many advantages such as no air pollution in the operating theatre, empty bowels, no organ (hepato-renal) toxicity, good peripheral perfusion and low cost, while this method has several disadvantages to overcome such as hypertension. There are many anesthetic agents for total intravenous anesthesia. However, sufentanil, alfentanil and propofol are not available. Droperidol, fentanyl and ketamine are the best combination for this purpose in Japan so far.

Adolescent↗
PubMed1990

[Plasma cortisol levels during abdominal surgery under sevoflurane anesthesia: comparison between gastrointestinal and gynecological surgery].

Plasma cortisol levels during abdominal surgery under sevoflurane anesthesia were evaluated in 22 patients who ranged in ages from 37 to 65. They underwent either gastrointestinal or gynecological abdominal surgery. Anesthesia was induced and maintained with sevoflurane (1-5%) in nitrous oxide (4 l.min-1) and oxygen (2 l.min-1). Succinylcholine was administered intravenously to facilitate tracheal intubation and pancuronium was given intravenously during surgery. Lactated Ringer's solution at a speed of 10-15 ml.kg-1.hr-1 was also administered intravenously throughout the surgical procedures. Plasma cortisol levels were unchanged with the induction of sevoflurane anesthesia alone, but they increased significantly 2-3 times of the preanesthetic levels during and after surgery in both groups. However, the concentrations of plasma cortisol after recovery from anesthesia were significantly higher in the gastrointestinal group than in the gynecological group. The findings suggest that plasma cortisol levels after surgery reflect the difference in magnitude of stress response between gastrointestinal and gynecological surgery.

Abdomen↗
PubMed1990

[Plasma catecholamine levels following continuous epidural infusion of morphine for postoperative analgesia in surgical patients].

Plasma catecholamine levels were measured to evaluate postoperative pain relief either with epidural morphine or systemic analgesics in sixteen patients who underwent gastrectomy. Eight patients (epidural morphine group) obtained postoperative analgesia with continuous epidural morphine with a pump (CADD-PCA, Model 5200P, Pharmacia). A bolus of morphine was administered through an indwelling thoracic (Th8 X 9) epidural catheter 3 hrs prior to the proposed end of the surgery, which was followed with continuous epidural infusion of morphine at a rate of 0.167-0.042mg.hr-1 by the pump during and after anesthesia and surgery with gradual decrease in dose until the third postoperative day. The remaining eight patients (systemic analgesics group) received repeatedly intravenous or intramuscular pentazocine and buprenorphine when needed. Plasma epinephrine levels increased significantly at the end of surgery in both groups, and were higher in the systemic analgesics group than those in the epidural morphine group. In the epidural morphine group, the catecholamine levels decreased to the previous day's levels on the first postoperative day and afterward, but remained high during three postoperative days in the systemic analgesics group. Plasma norepinephrine levels increased significantly at the end of surgery and afterward in both groups. However, they were significantly higher in the systemic analgesics group than in the epidural morphine group. Plasma dopamine levels were unchanged in the epidural morphine group during the surgical procedures, but they increased significantly on the first postoperative day and thereafter in the systemic analgesics group. Our study suggests that continuous epidural infusion of morphine is adequate for postoperative pain relief and exerts a suppressing effect on plasma catecholamine levels as compared with systemic analgesics regimen.

Adult↗
PubMed1990

[Sevoflurane anesthesia for a patient with arthrogryposis multiplex congenita].

We reported an anesthetic experience of a 6-year-old male patient with arthrogryposis multiplex congenita who underwent tonsillectomy and adenoidectomy. The induction and maintenance of anesthesia were smoothly performed with inhalation of 1-5% sevoflurane in nitrous oxide and oxygen. Emergence from anesthesia was also smooth. Halothane and succinylcholine chloride were not used to avoid possible hyperthermia. Anesthetic management of patients with arthrogryposis multiplex congenita was discussed citing literature references.

Adenoidectomy↗
PubMed1989

[Effects of surgical intervention on plasma levels of antidiuretic hormone and alpha-human atrial natriuretic polypeptide under sevoflurane anesthesia].

Effects of surgical intervention on plasma levels of antidiuretic hormone (ADH) and alpha-human atrial natriuretic polypeptide (alpha-hANP) under sevoflurane-nitrous oxide-oxygen anesthesia were evaluated in 24 patients, ranged in ages from 15 to 65, who underwent non-abdominal surgery (orthopedic surgery) or abdominal surgery (gastrointestinal or gynecological surgery). Anesthesia was induced and maintained with sevoflurane, nitrous oxide and oxygen. Succinylcholine was administered to facilitate tracheal intubation and pancuronium was given during abdominal surgery when needed. Lactated Ringer's solution was administered intravenously throughout the procedures. Neither plasma ADH nor alpha-hANP levels changed significantly during sevoflurane anesthesia alone for 20 min. Plasma ADH levels were unchanged during surgery in patients who underwent non-abdominal surgery, but they tended to increase although insignificantly after the recovery from anesthesia. On the contrary, plasma ADH levels increased significantly during surgery and in the recovery room in patients who underwent abdominal surgery. Plasma alpha-hANP levels were unchanged during surgery and in the recovery room in patients who underwent non-abdominal or abdominal surgery. The authors' findings suggest that ADH secretion was significantly stimulated with abdominal intervention but not with orthopedic one, furthermore neither anesthesia nor surgical stress induced any influence on plasma alpha-hANP levels.

Adolescent↗
PubMed1989

[Effects of sevoflurane anesthesia and surgery on plasma catecholamine levels].

Effects of sevoflurane-nitrous oxide-oxygen anesthesia and surgery on plasma levels of epinephrine, norepinephrine and dopamine were evaluated in twenty four patients who ranged in ages from 15 to 65 years. They underwent non-abdominal surgery (orthopedic surgery) or abdominal surgery (gastrointestinal or gynecological surgery). Anesthesia was induced and maintained with sevoflurane in 50% nitrous oxide and 50% oxygen. Succinylcholine was administered intravenously to facilitate tracheal intubation and pancuronium was given intravenously during surgery. Lactated Ringer's solution at a speed of 5-15 ml.kg-1.h-1 was also administered intravenously throughout the procedures. Neither plasma epinephrine, norepinephrine nor dopamine levels changed significantly during the anesthetic induction with sevoflurane anesthesia. Plasma catecholamines were unchanged during and after surgery in patients who underwent non-abdominal surgery, while plasma epinephrine and norepinephrine levels increased significantly during and after abdominal surgery. Plasma dopamine levels, however, were unchanged during and after surgery in these patients. The findings suggest that epinephrine and norepinephrine secretion was significantly stimulated with abdominal intervention but not with orthopedic one under sevoflurane anesthesia.

Adolescent↗
PubMed1989

[Effect of continuous epidural infusion of morphine for postoperative analgesia on pituitary-adrenocortical function].

Plasma levels of cortisol, ACTH and beta-endorphin like immunoreactivity (beta-ELI) were measured to evaluate postoperative pain relief with epidural morphine and systemic analgesics in conjunction with endocrine functions in 16 patients who underwent gastrectomy. Eight of these patients (epidural morphine group) obtained postoperative analgesia with continuous epidural infusion of morphine with a pump as in our previous report. A bolus of epidural morphine was administered through an indwelling thoracic (Th8,9) catheter at 3 hrs prior to the proposed end of the surgery, which was followed with continuous epidural infusion of morphine at a rate of 0.167-0.042 mg.hr-1 with a pump (CADD-PCA, Model 5200P, Pharmacia) during and after anesthesia and surgery with gradual decrease in dose until the third postoperative day. The remaining eight patients (systemic analgesics group) repeatedly received systemic pentazocine and buprenorphine when needed. Plasma cortisol levels increased significantly at the end of surgery and after in both groups. However plasma concentrations of cortisol in the epidural morphine group were significantly lower than those in the systemic analgesics group on the first and second postoperative days. Plasma levels of ACTH and beta-ELI increased significantly at the end of surgery but returned to levels of the previous day in both groups postoperatively. Our study suggests that continuous epidural infusion of morphine is adequate for postoperative pain relief and has suppressing effect on plasma cortisol levels as compared with systemic analgesics regimen.

Adult↗
PubMed1989

[Plasma morphine levels during its continuous epidural infusion].

We evaluated plasma levels of morphine during its continuous epidural infusion for postoperative analgesia in nine adult patients. A bolus injection of 3 mg of morphine was administered epidurally 3 hours prior to the proposed end of the surgery, and thereafter continuous epidural infusion of morphine was continued at a rate of 0.167-0.042 mg.hr-1 with a pump (CADD-PCA, 5200P, Pharmacia) during and after the surgery until the 3rd postoperative day. The dose of morphine was gradually decreased to 0.021-0.042 mg.hr-1 without reducing the quality of postoperative analgesia. Plasma morphine levels were measured by gas chromatography-mass spectrometry method. Plasma concentrations of morphine were 4.6 +/- 0.7 (Mean +/- SE) ng.ml-1 at the end of surgery and they decreased thereafter to 0.7 +/- 0.1 ng.ml-1, 0.3 +/- 0.1 ng.ml-1 and 0.1 +/- 0.1 ng.ml-1 on the 1st, 2nd and 3rd postoperative days, respectively. Plasma levels of morphine decreased gradually correlating with reduction of infused morphine. Adequate postoperative pain relief was obtained throughout the procedure without any severe complications such as respiratory depression. The analgesic effect of epidural morphine did not parallel with that of plasma concentration. Plasma concentrations of morphine administered by continuous epidural infusion with a pump were estimated to be lower than the minimum analgesic plasma concentration (10-40 ng.ml-1), and the toxic levels of morphine during continuous epidural infusion were not detected by our method.

Aged↗
PubMed1988

Importance of magnesium and potassium concentration on basal tone and 5-HT-induced contractions in canine isolated coronary artery.

1. In vitro studies were undertaken to investigate the effects of external potassium ([K+]o) and magnesium ([Mg2+]o) concentration on canine coronary arterial basal tone and on 5-hydroxytryptamine (5-HT)-induced contractions. 2. Acute withdrawal of, or reduction in, [K+]o produced relaxation of basal tone in isolated coronary arteries, whereas acute withdrawal (but not reduction) of [Mg2+]o produced contraction of these blood vessels. 3. The magnitude of coronary contraction obtained on withdrawal of [Mg2+]o was dependent upon the [K+]o; the higher the [K+]o, the greater the contraction. 4. The precise ratio of [K+]o/[Mg2+]o appeared to be important in dictating the degree of contraction (maximum response) and sensitivity (EC50) of canine coronary vascular smooth muscle cells to 5-HT. The EC50 to 5-HT was enhanced by increases in the [K+]o/[Mg2+]o ratio, whereas the ability of 5-HT to induce a maximal contraction was attenuated by decreases in the [K+]o; the latter being modulated by [Mg2+]o. Small changes in [Mg2+]o could effect large changes in the EC50 as [K+]o was lowered. 5. These actions took place over patho-physiological ranges of [K+]o and [Mg2+]o. 6. Maintenance of a constant [K+]o/[Mg2+]o ratio, irrespective of the exact [K+]o and [Mg2+]o, produced similar degrees of maximum tension. 7. Use of intact vascular ring preparations and helically-cut vascular strips produced similar results with varying [K+]o/[Mg2+]o. 8. A variety of pharmacological receptor antagonists (phentolamine, propranolol, atropine, diphenhydramine, cimetidine), as well as a prostaglandin cyclo-oxygenase inhibitor, did not modify the altered contractile responses or basal tone evoked by varying [K+]o/[Mg2+]o ratios. 9. These results suggest: (1) that basal tone and contractility of canine coronary vascular smooth muscle cells appear to be exquisitely sensitive to alterations in extracellular K+ and Mg2+; and (2) 5-HT receptor-operated Ca2+ channels, as well as those Ca2+ channels involved in generation of coronary arterial basal tone are modulated and controlled by the precise concentrations of [K+]o and [Mg2+]o.

Animals↗
PubMed1987

Continuous vs. bolus epidural morphine.

The clinical evaluation of continuous administration of epidural morphine was undertaken using an infusion pump (Act-A-Pump 1000). Eleven patients who had undergone abdominal surgical procedures were treated with this therapeutic modality for postoperative pain control, and two cancer patients for chronic pain relief. The results were satisfactory and the advantages over repeated epidural injections are discussed.

Adult↗