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Biomedical subjects

K Ohtaka

Publications and source records attributed to K Ohtaka.

34 records · Page 2Linked to original sources

[Effect of continuous infusion of diltiazem on cardiovascular responses to laryngoscopy and intubation].

We studied the cardiovascular responses to laryngoscopy and intubation in 30 patients who received continuous infusion of either diltiazem 10 micrograms.kg-1.min-1, 40 micrograms.kg-1.min-1 or saline as control group during 20 min before induction. Heart rate, arterial pressure, rate pressure product (RPP), pressure rate quotient (PRQ) were measured starting 20 min before induction to 3 min after tracheal intubation. The increases in arterial pressure and RPP following tracheal intubation were reduced significantly in patients receiving diltiazem 40 micrograms.kg-1.min-1, but they were not reduced in patients receiving diltiazem 10 micrograms.kg-1.min-1 compared with control. We conclude that continuous infusion of diltiazem during 20 min before induction is effective for preventing the increases in arterial pressure and RPP following tracheal intubation, and the optimal infusion rate is from 10 to 40 micrograms.kg-1.min-1.

Aged↗

[Continuous intravenous pethidine infusion for analgesia after upper abdominal surgery: a randomized, prospective double-blind comparison with continuous epidural infusion of pethidine].

We conducted a randomized double-blind controlled study comparing patients receiving continuous intravenous pethidine infusion with those receiving continuous epidural infusion for postoperative analgesia after upper abdominal surgery. Twenty patients scheduled for upper abdominal surgery were randomized into 2 groups: IV Group (n = 10) received 100 mg.24 h-1 of pethidine intravenously and saline epidurally, Epi Group (n = 10) received 100 mg.24 h-1 of pethidine epidurally and saline intravenously. During 24-hour postoperatively, verbal descriptor pain scale, sedative scale, respiratory rate, pulse rate and blood pressure were evaluated at each 2 hours. During 72-hour postoperatively, visual analogue pain scale (added at 6-hour postoperatively), supplemental doses of pethidine, and side effects were evaluated at each period of 12 hours. There was no significant difference in the rating of analgesia in either group during 72-hour postoperatively. However in the first 12 hours postoperatively, VAS in Epi Group tended to be lower than that in IV Group. There was no respiratory depression in either group. We conclude that continuous intravenous infusion of 100 mg.24h-1 of pethidine was effective for postoperative analgesia after upper abdominal surgery without major side effects, and almost the same analgesic effect was obtained as compared with continuous epidural analgesia.

Abdomen↗

[The effect of continuous epidural infusion of a combination of 1% mepivacaine and buprenorphine for post-operative pain relief].

Using a portable 2 ml.hr-1 type infusor (Baxter Infusor), the effect of continuous epidural infusion for post-operative pain relief for 72 hours was studied in 32 patients after upper abdominal surgery. The patients were randomly allocated into four groups: Group 1 (n = 8) received continuous epidural infusion of 1% mepivacaine and buprenorphine 0.2 mg (48 ml.hr-1); group 2 (n = 8) 1% mepivacaine and buprenorphine 0.4 mg (48 ml.hr-1); Group 3 (n = 8) saline and buprenorphine 0.2 mg (48 ml.hr-1); Group 4 (n = 8) saline and buprenorphine 0.4 mg (48 ml.hr-1). The effect was evaluated at intervals of 12-hour until 72 hours postoperatively. Patients received supplemental buprenorphine intramuscularly as needed. In each period during the 12 to 72-hour after operation, the percentage of the patients who needed no supplemental buprenorphine was 62.5-100%, which is higher than during the 0 to 12-hour (25.0%). The percentage of the patients who showed no pain on coughing and changing in position in Group 1 and 2 was higher than in Group 3 and 4 in each period (P less than 0.05 12-24 and 36-72 hr). Continuous epidural infusion using Baxter Infusor with the combination of 1% mepivacaine and buprenorphine is effective for alleviating postoperative pain during the 12 to 72 hours after the operation, and for prevention of pulmonary complications.

Abdomen↗

[The evaluation of incremental positive end-expiratory pressure on right ventricular hemodynamics as determined by the thermodilution technique].

Effects of incremental positive end-expiratory pressure (PEEP) on right ventricular (RV) hemodynamics were studied in 10 patients undergoing coronary artery bypass grafting, abdominal aneurysmectomy and partial hepatectomy, using Swan-Ganz catheter mounted with the rapid response thermistor. PEEP was increased from 0 (baseline) to 15 cmH2O with increment of 5 cmH2O, and right ventricular ejection fraction (RVEF), RV end-diastolic volume (RVEDV), RV end-systolic volume (RVESV), and cardiac output (CO) were computed with a thermodilution technique at each PEEP. At 15 cmH2O PEEP, RVEF, RVEDVI and RVESVI were comparable with the baseline, while right arterial pressure, RV peak systolic pressure and mean pulmonary arterial pressure increased significantly compared with the baseline. Increased afterload of RN caused by PEEP did not affect RV contractility. Decreased cardiac and stroke volume indices were attributed to the decrease of preload caused by the increase of intrathoracic pressure. We conclude that PEEP at 5 to 15 cmH2O does not influence right ventricular hemodynamics, and RVEDV is a reliable index to monitor RV hemodynamics instead of right arterial pressure to determine optimal PEEP.

Aged↗

[Ventricular arrhythmia associated with the use of an electrosurgical unit in a patient with a Swan-Ganz catheter].

We experienced short-run type ventricular arrhythmia associated with use of electrosurgical unit (ESU) in a patient with a Swan-Ganz catheter. Leakage current was not detected from the body of the five different devices used in this study. Nevertheless, there is a possibility of leakage current to the electrode of the intra-cardiac catheter thereby exciting the myocardium, because the grounding of the five devices used simultaneously on the patient were not of EPR system. The other possibility, that is the occurrence of pulse direct current voltage by rectification of high frequency current at the contact point of electrosurgical knife's tip and vital organ is a speculation but not underlined by a definite proof. In summary, the cause of ventricular arrhythmia associated with the use of ESU could not be identified in the present case. It must always be remembered that whatever safety measures may be prescribed for electrical instruments, a complete prevention of EMI is impossible. Also it must be stressed that whenever many devices are used simultaneously on a patient, EPR system is very important for avoiding electrical hazard.

Arrhythmias, Cardiac↗

[Continuous intravenous infusion of pethidine or buprenorphine for postoperative analgesia].

Efficacy of continuous intravenous infusion for postoperative analgesia was evaluated in 20 patients who had undergone abdominal surgery for 72 hours postoperatively. The patients were randomly allocated to two groups: one group received continuous intravenous infusion of buprenorphine at 0.2 mg.24 hr-1 using a non-electronic, portable infusor 0.5 ml.hr-1 type (Baxter), while the other received infusion of pethidine at 50 mg.hr-1. During the first 12 postoperative hours, the frequency of "Fair" rating which indicated need of supplemental analgetics was significantly higher than the later 12-hour period until 72 hours in both groups. However, although during the first 12 hours continuous intravenous infusion was inadequate to alleviate postoperative pain compared with other 12-hour period, no patient received supplemental analgesics more than 2 times. During the 24 to 72 postoperative hours, 70% of cases needed no supplemental analgesics to alleviate postoperative pain. Continuous intravenous infusion of 0.2 mg.hr-1 buprenorphine or 50 mg.hr-1 pethidine was inadequate for postoperative analgesia during immediately after the operation to 36 hours postoperatively, especially during the first 12-hour period. However, this infusion was effective during 36 to 72 postoperative hours. There was no significant difference between buprenorphine group and pethidine group.

Aged↗

[A case of delirium which occurred during otorhinolaryngological treatment under local anesthesia--the importance of close communication between practitioners and local general hospitals].

We experienced a case of delirium which occurred during treatment of chronic sinusitis under local anesthesia in a ENT practitioner, which took an unique course. We were able to treat the patient immediately after occurrence of the complication because we have emergency hot-line between anesthesiologists in our hospital and the practitioners in our area. Fortunately the patient recovered without severe sequelae due to immediate therapy. We consider that in emergency cases, a close communication between practitioners and local general hospitals is important for exact diagnosis and suitable treatments as well as for life-saving procedures.

Anesthesia, Local↗

[Evaluation of the efficacy of continuous epidural block with low concentration of local anesthetics in patients with ureterolithiasis].

Forty patients with ureterolithiasis were studied to evaluate the efficacy of a continuous epidural block with local anesthetics. The patients were randomly allocated into 3 groups: first group (n = 7) received continuous epidural administration of 1% mepivacaine at a rate of 2 ml.hr-1; second group (n = 19) received intermittent bolus administration of the same anesthetic 4-5 times daily; and third group (control group, n = 14) was treated by conventional therapy including infusion of Ringer's solution and diuretics. Among 3 groups, a comparison of the rate of abortion of ureter stone, the rate of mobilization of stone, and the frequency of operation was performed. The rate of abortion in group 1 was significantly higher than those of group 2 and control. The rate of mobilization of stone in group 1 tended to be higher than group 2 and control. Also the frequency of operation in group 1 tended to be lower than group 2. Effect of continuous administration with 1% mepivacaine in patient with ureterolithiasis was comparable to that of intermittent bolus administration of 2% mepivacaine or 0.5% bupivacaine reported. We conclude that the continuous block with 1% mepivacaine is effective and safe for treating the patient with ureterolithiasis.

Adult↗

Obsessive-compulsive symptoms in childhood and adolescence.

We investigated 61 patients (38 boys and 23 girls) under 18 years of age with obsessive-compulsive symptoms seen in the Department of Psychiatry, Nagoya University Hospital, from 1982 until 1986. In this period, a total of 1293 patients under 18 years of age visited the clinic. The percentage of patients with obsessive-compulsive symptoms was 5%. The earliest onset of symptoms was at age 3 years, and the average age of onset was 11.6 years. We found no particular tendency in terms of the number of siblings and the birth order of the patients. Obsessive traits were the fundamental personality traits of patients. Moreover, according to the other characteristics of personality, the patients were subdivided into schizothymic, viscous temperament, and cyclothymic. Parents of the patients were more apt than usual to have obsessive-compulsive personalities. Psychiatric disturbances and occupations were also investigated. Incidents related to school situations commonly triggered obsessive-compulsive symptoms. The most frequently noted obsessive thought was dirt phobia, and the most common compulsive behavior was washing. School refusal and violence at home were especially common as associated symptoms of obsessive-compulsive symptoms. We also describe the treatment regimen and the outcomes of the patients.

Adolescent↗

Nd:YAG laser therapy for infertility with a contact-type probe.

Laparoscopic Nd:YAG laser surgery for tubal adhesiolysis, hydrosalpinx and other disorders is an effective treatment for female infertility that causes relatively little tissue damage. In initial studies using contact-type probes, the 0.4-mm-diameter probe and 10 mm/sec incision speed were found to cause less tissue degeneration than did other combinations (P less than .05). Fifteen infertile women were treated at laparoscopy with a Nd:YAG laser; one of six with hydrosalpinx achieved pregnancy after salpingostomy using a contact-type probe, two of three with tubal adhesions achieved pregnancy after adhesiolysis with the Nd:YAG laser, and three of six with polycystic ovaries achieved pregnancy after wedge resection using a contact-type probe. Five of fifteen infertile women conceived after Nd:YAG laser surgery with a contact-type probe under laparoscopy. We confirmed that contact irradiation with a ceramic incising probe is capable of creating an adequate incision at low power levels and that laparoscopic Nd:YAG laser surgery for infertile women is an effective treatment.

Adult↗

O,O,S-trimethyl phosphorothioate increases Ca2+ independent nitric oxide synthase activity in the lung but decreases Ca2+/calmodulin dependent type in the cerebellum in Fischer 344 rats.

In the present study, we investigated the possible role of nitric oxide synthase in lung injury using female Fischer 344 rats as a model animal and O,O,S-trimethyl phosphorothioate as an example of lung toxicants. One form of nitric oxide synthase, Ca2+/calmodulin dependent type, decreased monotonously in a dose-dependent manner in the cerebellum. In contrast, O,O,S-trimethyl phosphorothioate increased activities of Ca2+ independent nitric oxide synthase in the lung in a dose-associated manner from 5 mg/kg to 15 mg/kg, but decreased at 30 mg/kg. Lung toxicity of O,O,S-trimethyl phosphorothioate, however, as judged both by functional impairments (PaCO2 and [HCO3-]) and histopathological changes, increased sharply at 30 mg/kg. We thus tested the hypothesis that a potent nitric oxide synthase inhibitor, NG-nitro-L-arginine-methyl ester, may modify lung injury induced by O,O,S-trimethyl phosphorothioate. Treatment with NG-nitro-L-arginine-methyl ester at 20 mg/kg/day aggravated lung injury induced by O,O,S-trimethyl phosphorothioate: Pulmonary oedema and bleeding occurred, leading to an increase in mortalities at 15 mg/kg of O,O,S-trimethyl phosphorothioate, at which level it did not induce such changes as when dosed alone. These findings indicate that nitric oxide synthase in the lung might play a protective role in lung injury.

Amino Acid Oxidoreductases↗

Enhanced levels of lipid peroxidation and xanthine oxidase activity in the lung of male Sprague-Dawley rats following treatment with O,O,S-trimethyl phosphorothioate.

The purpose of this study was to investigate the roles of lipid peroxidation and a prototypical radical generating enzyme, xanthine oxidase, in lung injury caused by O,O,S-trimethyl phosphorothioate (OOS-TMP). Animals (five per group) were dosed with OOS-TMP at 40 mg/kg and sacrificed on the 1st, 3rd or 7th day after treatment. OOS-TMP increased lipid peroxidation (Mean +/- S.E.) to 139 +/- 9.6% of the control values in the lung and to 623 +/- 203% in the liver on the 1st day. When rats were dosed with OOS-TMP at 20, 40 and 60 mg/kg, lipid peroxidation in the lung and the liver were increased in a dose-dependent manner. In the lung, the total activity of xanthine oxidase was coincidentally increased. In contrast, the activities of superoxide dismutase and catalase were not affected. Effects of OOS-TMP on lipid peroxidation and the total activity of xanthine oxidase were completely abolished by coadministration with O,O,O-trimethyl phosphorothionate of a non-toxic dose (1 mg/kg), which antagonizes the lung injury after treatment with OOS-TMP. The present results indicate that free radical formation may be involved in lung injury after OOS-TMP treatment through activation of radical producing enzymes such as xanthine oxidase.

Animals↗