Biomedical subjects

F Handa

Publications and source records attributed to F Handa.

At least 55 records · Page 3Linked to original sources

PubMed2001

Measurement of B(0)(d)-B_(0)(d) mixing rate from the time evolution of dilepton events at the upsilon(4S).

We report a determination of the B(0)(d)-&B_(0)(d) mixing parameter Deltam(d) based on the time evolution of dilepton yields in Upsilon(4S) decays. The measurement is based on a 5.9 fb(-1) data sample collected by the Belle detector at KEKB. The proper-time difference distributions for same-sign and opposite-sign dilepton events are simultaneously fitted to an expression containing Deltam(d) as a free parameter. Using both muons and electrons, we obtain Deltam(d) = 0.463+/-0.008 (stat)+/-0.016 (syst) ps(-1). This is the first determination of Deltam(d) from time evolution measurements at the Upsilon(4S). We also place limits on possible CPT violations.

Journal Article↗

PubMed2001

Measurement of the CP violation parameter sin2 phi(1) in B(0)(d) meson decays.

We present a measurement of the standard model CP violation parameter sin2 phi(1) (also known as sin2beta) based on a 10.5 fb(-1) data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric e(+)e(-) collider. One neutral B meson is reconstructed in the J/psiK(S), psi(2S)K(S), chi(c1)K(S), eta(c)K(S), J/psiK(L), or J/psipi(0) CP-eigenstate decay channel and the flavor of the accompanying B meson is identified from its charged particle decay products. From the asymmetry in the distribution of the time interval between the two B-meson decay points, we determine sin2 phi(1) = 0.58(+0.32)(-0.34)(stat)+0.09-0.10(syst).

Journal Article↗

PubMed2001

The efficacy of oral clonidine premedication in the prevention of postoperative vomiting in children following strabismus surgery.

We evaluated the efficacy of clonidine given orally preoperatively for preventing postoperative vomiting (POV) in children undergoing propofol-nitrous oxide anaesthesia for strabismus surgery. Sixty children, ASA physical status I, aged 2-12 years, received diazepam, 0.4 mg x kg(-1) or clonidine, 4 microg x kg(-1) (n=30 each) orally, in a randomized double-blind manner. These drugs were given 105 min before an inhalational induction of anaesthesia. A complete response, defined as no POV and no need for rescue antiemetic medication, during 0-24 h after anaesthesia was 67% with diazepam and 93% with clonidine, respectively (P=0.024). No clinically adverse event was observed in any of the groups. In summary, pretreatment with oral clonidine enhances the antiemetic efficacy of propofol for the prevention of POV after paediatric strabismus surgery.

Administration, Oral↗

PubMed2001

[Anesthetic management of parturients with Marfan syndrome].

Ten pregnancies and 7 deliveries in 5 patients of Marfan syndrome were managed at our institution. Three patients were delivered with a cesarean section under general anesthesia, and one was delivered under epidural anesthesia. Three underwent vaginal delivery with epidural anesthesia. Two patients selected induced abortion, and one had a spontaneous abortion. Six of 7 neonates and all 5 mothers survived without any sequela. One had intrauterine fetal death due to dissection of aortic aneurysm. Simultaneous cesarean section and cardiovascular operation under cardiopulmonary bypass were performed in one case. In the parturient without progress of cardiovascular complication during pregnancy, painless labor under epidural anesthesia is our first choice to minimize hemodynamic derangement. Invasive arterial blood pressure and central venous pressure were monitored in all cases of vaginal delivery for tight hemodynamic control. Epidural anesthesia is also preferred in cases of elective cesarean section for obstetric indication. Emergency cesarean sections are performed in the cases of progressive dissection and urgent obstetric indication. General anesthesia was induced with fentanyl and midazolam to minimize cardiovascular response to tracheal intubation. We emphasize that evaluation of cardiovascular status and multidisciplinary approach are the key in the anesthetic management of parturients with Marfan syndrome.

Adult↗

PubMed2001

[Severe pulmonary edema in a preeclamptic patient with peripartum cardiomyopathy].

We report a preeclamptic patient who revealed severe pulmonary edema. A 37-year-old woman, at 32-week gestation, underwent emergency cesarean section under general anesthesia. She had no particular past medical history. SpO2 was 84% (room air) on the arrival at the operating room, and a chest X-ray showed pulmonary edema. She was managed in the intensive care unit postoperatively, she received an intensive treatment (positive pressure ventilation, furosemide, and inotropic support), and was extubated successfully on the third postoperative day. From clinical course and echocardiographic findings, we consider that this pulmonary edema was caused by peripartum cardiomyopathy.

Adult↗

PubMed2000

Effects of oral clonidine premedication on side effects of intravenous ketamine anesthesia: a randomized, double-blind, placebo-controlled study.

STUDY OBJECTIVE: To determine the effects of oral clonidine premedication on hemodynamic changes during the entire course of ketamine anesthesia and incidence of postoperative adverse reactions. DESIGN: Randomized, prospective, double-blind, placebo-controlled study. SETTING: Department of Anesthesiology, University of Tsukuba Hospital, Ibaraki, Japan. PATIENTS: 39 ASA physical status I and II patients undergoing superficial surgeries. INTERVENTIONS: Placebo, clonidine 2.5 micrograms/kg, and clonidine 5 micrograms/kg groups received respective doses of oral clonidine 90 minutes prior to surgery. Anesthesia was induced with ketamine 2 mg/kg intravenously (i.v.), trachea was intubated, and anesthesia was maintained with 67% nitrous oxide, oxygen, and supplemental ketamine (1 mg/kg) when systolic blood pressure and heart rate (HR) exceeded 180 mmHg and 100 bpm, respectively. MEASUREMENTS AND MAIN RESULTS: In the clonidine 2.5 micrograms/kg group, HR response to tracheal intubation was significantly less, while in the clonidine 5 micrograms/kg group both mean arterial pressure and HR responses were significantly suppressed, compared with the placebo group. Intraoperative coefficients of variations of HR were significantly less in both clonidine groups than the placebo group. Incidence of nightmare and degree of salivation were significantly less in the clonidine 5 micrograms/kg group than in the placebo group. CONCLUSION: Oral clonidine 2.5 micrograms/kg and clonidine 5 micrograms/kg attenuates cardiostimulatory effects, while clonidine 5 micrograms/kg was associated with reduced incidence and severity of nightmare and salivation attributable to i.v. ketamine.

Administration, Oral↗

PubMed2000

[Anesthetic management in pediatric interventional cardiology].

Interventional cardiology (n = 108) and cardiac angiography (n = 481) procedures in pediatrics performed between January 1996 and December 1998 were reviewed. Means (SD) of duration of anesthesia for interventional cardiology and cardiac angiography were 245 (130) and 152 (48) minutes, respectively (P < 0.001). Incidences of long operations requiring over 6 hours of anesthesia were 12 and 0%, respectively (P < 0.001). Incidences of hemodynamic derangements were 17 and 2.9%, and catheter-related complications were 7.4 and 0.83%, respectively (P < 0.001). Incidences of ICU admission were 7.4 and 0.62% those of emergency surgery were 4.6 and 0%, and those of blood transfusion were 4.6 and 0%, respectively (P < 0.001). Incidences of cardiopulmonary resuscitation, and cardioversion were also higher in interventional cardiology (P < 0.05), and all these emergency cases were rescued successfully. The risk of cardiac angiography is higher compared with general surgery, and the risk of interventional cardiology is higher than cardiac angiography in pediatrics. This study reconfirms that anesthesiologists should play an active role in care of pediatric patients undergoing high-risk procedures outside the operating room.

Anesthesia, General↗

PubMed2000

[Anesthesia in a children's hospital in Nepal].

The author experienced ten cases of anesthesia in a children's hospital in Nepal. Eight cases were pediatric surgeries and two cases were gynecological procedures. Halothane or intravenous ketamine anesthesia was performed in pediatric cases. Regional block or intravenous ketamine anesthesia was performed in gynecological cases. Oxygen supply stopped during anesthesia in one case, and patient was resuscitated by ambu-bag with room air. Electricity was interrupted in one case, and operation was continued with only one battery light. There is no mechanical ventilator nor nitrous oxygen in the hospital. Air conditioning was not in the operating room although the hospital was situated in the subtropical area and room temperature reached up to 40 degrees. Electrocardiogram and suction machines were present, but they were out of order. The anesthetic technique required in the developing countries is not so simple. Especially for young doctors trained among so many sophisticated monitors, anesthesia in the developing countries is not only an experience of volunteer, but provides effective training of pediatric anesthesia for strengthening their sense and skills.

Adult↗

PubMed1997

Oral clonidine premedication decreases energy expenditure in human volunteers.

PURPOSE: Clonidine not only stops postoperative shivering and decreases oxygen consumption, but also decreases energy expenditure with or without a reduction in shivering during recovery from anaesthesia. It is important to see if clonidine decreases energy expenditure at rest since this may contribute to a postoperative decrease in energy expenditure. The authors tested the hypothesis that oral clonidine decreases energy expenditure at rest. METHODS: Twenty healthy male volunteers were randomly assigned to one of two groups. Ten volunteers received oral clonidine approximately 5 micrograms.kg-1 (clonidine group), while the remaining 10 volunteers received placebo (control group). Blood pressure, heart rate, body temperature at the tympanic membrane, sedation score graded from 1 (alert) to 5 (sleeping and difficult to be aroused by tactile stimulation) were measured before and at 30-min intervals for three hours after administration of clonidine or placebo. Measurements of energy expenditure and respiratory quotient were made with a head canopy system at one-minute intervals and averaged over 15 min before, and at 30, 60, 90, 120, and 180 min after administration of clonidine or placebo. RESULTS: Sedation score increased from 1 to 3 (median) after clonidine administration. Energy expenditure decreased from 1452 +/- 225 kcal.24hr-1 (mean +/- SD) at baseline to 1258 +/- 175 kcal.24hr-1 at 180 min after clonidine administration (P < 0.05). CONCLUSION: This study suggests that oral clonidine at a dose of 5 micrograms.kg-1 decreases energy expenditure at rest.

Administration, Oral↗

PubMed1997

[Anesthetic management of parturients with intracranial arteriovenous malformation].

We have retrospectively analyzed twelve pregnancies in nine patients with intracranial arteriovenous malformation (AVM) managed at our hospital from 1984 to 1995. Following radical excision of AVM before or during pregnancy in 6 cases, transvaginal deliveries were performed without untoward sequelae. In three of five patients who received non-curative treatments, labor analgesia was provided using epidural local anesthetics. One patient who presented with ruptured AVM followed by medical therapy, elective cesarean section was performed under spinal anesthesia with a favorable outcome. Anesthesia courses in two patients for the resection of ruptured AVM during pregnancy were uneventful under enflurane and nitrous oxide anesthesia, or balanced anesthesia using fentanyl and nitrous oxide in oxygen. Simultaneous cesarean section craniotomy was not performed at our hospital.

Analgesia, Obstetrical↗

PubMed1997

[Pre- and post-operative management of cesarean section in a parturient with severe preeclampsia accompanied by hyperdynamic state].

A 37-year-old parturient with severe preeclampsia accompanied by pulmonary edema underwent emergency cesarean section. Pulmonary artery (PA) catheter inserted while the patient was awake revealed hyperdynamic state with increased cardiac index and preload, and decreased systemic vascular resistance. Epidural anesthesia and analgesia were provided with a satisfactory outcome. Monitoring of PA pressure and cardiac index was continued postoperatively in ICU for fluid management. We conclude that preoperative PA catheterization provides useful hemodynamic information in severe preeclamptic patients associated with persistent oliguria, pulmonary edema and hyperdynamic state.

Adult↗

PubMed1988