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Biomedical subjects

S Dohi

Publications and source records attributed to S Dohi.

At least 181 records · Page 10Linked to original sources
PubMed1989

[Anesthetic management of a patient with severe subarachnoid hemorrhage and diffuse lung edema].

One of the most common problems in emergency anesthesia for cerebral aneurysm surgery is clinically significant ECG abnormalities. We had a 58 year old patient with severe subarachnoid hemorrhage and diffuse lung edema leading to fatal outcome probably due to catecholamine myocardial injury. During the operative intervention with enflurane and oxygen anesthesia, ST elevation on ECG suddenly appeared and heart failure developed in this patient. Intraoperative ECG suggested the development of acute myocardial infarction of the anterior and inferior wall, but echocardiography revealed a discrepant result; the wall motion abnormality was confirmed in the apex only. The serum CPK in this patient increased a little over the normal limit perioperatively. Overall results suggested that a cause of this patient's death was myocardial injury due to the excessive release of catecholamine. Therefore, we urge the need of through cardiac examinations as well as the administration of preventive drugs for catecholamine myocardial injury in the perioperative management of patients with severe subarachnoid hemorrhage.

Anesthesia, Inhalation↗
PubMed1988

[Estimation of absorbed dose of beta radiation into the critical tissues by a single injection of tritiated water].

The biological effects of tritium in humans need to be clarified, because the chances of humans becoming exposed to tritium beta radiation may increase with the development of the nuclear fusion reactor. To evaluate the biological effects of tritium, it is necessary to estimate exactly the absorbed dose from the tritium beta rays in the tissue. In many reports, the absorbed dose of HTO in the tissues is estimated from the tritium content in body fluid and dose calculations are customarily based upon the water content of soft tissues, which is taken to be 0.7 to 0.8. However, these methods may not show the exact absorbed dose in the organs. In the present study, the radioactivity of the critical tissues was measured directly using a sample oxidizer and the absorbed dose was calculated from the radioactivity of tritium in the tissues. Details on the method for calculation of the absorbed dose in tissues of the mouse is shown in this report. The results suggest that the absorbed dose should be obtained from the radioactivity in the tissues.

Absorption↗
PubMed1988

Heart rate response to atropine in humans anaesthetized with five different techniques.

Atropine, 0.01 mg.kg-1, was given intravenously before the start of surgery to 169 patients who were anaesthetized with one of five different techniques; halothane, enflurane, cervical epidural, lumbar epidural or narcotic anaesthesia in addition to nitrous oxide and oxygen. Atropine produced a significant increase in heart rate (HR) within 1 min in all patients studied; the HR increases in patients anaesthetized with halothane (37 +/- 11 beats.min-1, n = 37) or narcotic (34 +/- 12 beats.min-1, n = 30) were significantly greater than in those anaesthetized with enflurane (25 +/- 10 beats.min-1, n = 35; P less than 0.01) or epidural anaesthesia. Because of the presence of an acute cardiac sympathectomy, the patients who received cervical epidural anaesthesia were expected to have different responses to the atropine. However, there was no significant difference in the HR increases between the patient groups with cervical (19 +/- 12 beats.min-1, n = 32) and lumbar (22 +/- 8 beats.min-1, n = 35) epidural anaesthesia. Atropine also produced a small but significant increase in arterial pressure in all five groups of patients. These results suggest that the cardiac responses to atropine may differ depending on the individual anaesthetic agent used, and are likely dependent upon the agent's effect on autonomic nervous system activity.

Adolescent↗
PubMed1988

[Experimental study on the effectiveness of BRM in radiation therapy--OK-432 and cyclophosphamide].

We have previously demonstrated that specific antitumor cell-mediated immunity in host mice was induced or enhanced by local irradiation to tumor. In this study, the immunological status of host mice with transplanted tumor were modified by using OK-432 as immunostimulator and cyclophosphamide as suppressor of suppressor T-cells before and/or after local irradiation to tumor. The results indicate that the combined use of immunomodifier and radiation is more effective in the tumor radiotherapy. Three factors as follows: the interval of drug and radiation, the times of treatments and dose of immunostimulator and immunosuppressor, are very important in these combined therapy.

Animals↗
PubMed1987

Carbon dioxide elimination during circulatory arrest.

To learn modes of CO2 elimination during cardiac arrest, we continuously measured end-tidal CO2 concentration (ETCO2) in acutely arrested dogs with constant ventilation. A decrease in peak ETCO2 during cardiac arrest in each dog showed a washout biexponential function when graphed on semilog paper. The average half-times of each compartment were 19.2 +/- 3.1 (SD) sec for the fast compartment and 108.1 +/- 23.8 sec for the slow compartment; the fast compartment of the CO2 elimination curve suggested that CO2 was eliminated from the functional residual capacity, while the slow compartment indicated CO2 elimination from the pulmonary capillary blood and tissue stores. Neither pretreatment with sodium bicarbonate (1 mEq/kg iv) nor a 5-min cardiorespiratory arrest altered the mode of CO2 elimination. The ETCO2 also reflected the potential effects of external cardiac compressions on pulmonary blood flow, as previously reported. Besides mixed venous blood CO2 flowing back to the lungs by cardiac compressions, it should be noted that both alveoli and pulmonary capillary blood CO2 are also reflected in the ETCO2 during the first minute of CPR.

Animals↗
PubMed1987

Spinal cord blood flow during spinal anesthesia in dogs: the effects of tetracaine, epinephrine, acute blood loss, and hypercapnia.

To examine the effects of subarachnoid tetracaine and epinephrine on spinal cord blood flow (SCBF), lumbar SCBF and cerebral blood flow (CBF) were measured simultaneously by the hydrogen clearance technique in dogs (n = 45) anesthetized with halothane. The lumbar subarachnoid administration of tetracaine, 5 mg dissolved in 1 ml of a 7.5% dextrose solution had no significant effect on either SCBF or CBF for 4 hr even though arterial blood pressure and heart rate decreased significantly. After subarachnoid epinephrine alone (100, 300, and 500 micrograms), SCBF varied widely but did not change significantly with any of the injections, nor did CBF. Responses of SCBF to hypercapnia and to acute blood loss during spinal anesthesia with tetracaine were also examined. Increased PaCO2 (from 35 to 57 mm Hg) increased both SCBF and CBF similarly before and after subarachnoid tetracaine; SCBF increased from 26.8 +/- 9.0 ml X 100 g-1 X min-1 (mean +/- SD) before to 34.2 +/- 13.6 ml X 100 g-1 X min-1 during hypercapnia during spinal anesthesia, which was almost identical to the increase (from 31.5 +/- 8.1 ml X 100 g-1 X min-1 to 39.9 +/- 6.0 ml X 100 g-1 X min-1) before spinal anesthesia. Whereas acute blood loss (approximately 20% of estimated blood volume) during spinal anesthesia with tetracaine caused a 23% reduction of SCBF (P less than 0.05), in the absence of tetracaine SCBF remained unchanged during hemorrhagic hypovolemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, Spinal↗