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Biomedical subjects

Yoshihiro Hirabayashi

Publications and source records attributed to Yoshihiro Hirabayashi.

At least 19 recordsLinked to original sources

Simultaneous determination of six HIV protease inhibitors (amprenavir, indinavir, lopinavir, nelfinavir, ritonavir and saquinavir), the active metabolite of nelfinavir (M8) and non-nucleoside reverse transcriptase inhibitor (efavirenz) in human plasma by high-performance liquid chromatography.

We report the development of a simple, economical and reliable chromatographic method for the simultaneous determination of six HIV protease inhibitors (PIs; amprenavir, indinavir, lopinavir, nelfinavir, ritonavir and saquinavir), the active metabolite of nelfinavir (M8) and the non-nucleoside reverse transcriptase inhibitor (NNRTI; efavirenz) in human plasma. After extraction from plasma with an ethyl acetate-acetonitrile mixture, the analytes were separated on a phenyl column with a gradient of acetonitrile and phosphate solutions, and detected at three ultraviolet wavelengths. Calibration curves were linear over the range 0.025-15 microg/mL for saquinavir and 0.05-15 microg/mL for the other analytes. The accuracies ranged from -6.9% to +7.6%, and the intra-assay and inter-assay precisions were <9.2 and <11.8%, respectively. Our method, covering most of the PIs and NNRTIs currently used, facilitates ready therapeutic drug monitoring in hospital laboratories.

Alkynes↗

Aggravation of laryngeal rheumatoid arthritis after use of a laryngeal mask airway.

We report a case of aggravation of laryngeal rheumatoid arthritis (RA) after the use of a laryngeal mask airway (LMA). The patient was a 55-year-old woman with severe RA who underwent wrist arthrodesis under general anesthesia using a size 3 LMA. A few days after the operation, she reported hoarseness. Inflammation of the arytenoid region and vocal cord immobility were observed by fiberoptic nasolaryngoscopy. Vocal function returned to normal by postoperative day 42 in response to prednisolone therapy. In this case, stridor was misdiagnosed preoperatively, and postoperative symptoms and local findings were probably caused by aggravation of laryngeal RA resulting from substantial compression of the arytenoid region by the LMA. For patients with RA referred for surgery, a careful search for cricoarytenoid arthritis is essential, particularly in those with laryngeal stridor, because it may be aggravated after general anesthesia.

Arthritis, Rheumatoid↗

[Case of anaphylactic shock induced by an antibiotic after induction of anesthesia].

We report a case of anaphylactic shock induced by an antibiotic administrated after induction. A 39-year-old man was scheduled for removal of right adrenal tumor. After insertion of an epidural catheter, anesthesia was induced with an intravenous bolus injection of fentanyl 100 microg, propofol 130 mg and vecuronium 6 mg. The trachea was intubated smoothly and anesthesia was maintained with sevoflurane. Sultamicillin tosilate was administrated intravenously. Soon, ephedrine 12 mg was given intravenously because his blood pressures decreased. However, his blood pressure did not recover, but fell down to 35/22 mmHg. He was turned to head-down position, and 100% oxygen was administrated. Following epinephrine 0.1 mg injection, his blood pressure increased to 80/40 mmHg. Epinephrine at 0.005-0.02 microg x kg(-1) x min(-1) was infused continuously to maintain his blood pressure. We found erhythemia on his face, shoulders and arms. Hydrocortisone sodium succinate and acetate Ringer's solution were administrated to treat his anaphylactic shock and the surgery was postponed. The blood samples indicated that this event was IgE-mediated anaphylactic reaction. From his past history, penicillin allergy was confirmed. The surgery was rescheduled and anesthesia was managed in the same way as previous one. Surgery was successfully performed using levofloxacin, which had been taken orally before induction of anesthesia.

Adrenal Gland Neoplasms↗

[Neuropathy in the upper extremity after anesthesia].

BACKGROUND: The purpose of this study was to demonstrate the frequency of neuropathy in the upper extremity after anesthesia. METHODS: We reviewed the postoperative courses of 5454 patients who had received surgical procedures at the Jichi Medical School Hospital from 2004 January to 2004 December. RESULTS: Neuropathy developed in 33 patients (0.7%). In 28 of 33 patients (0.6%), symptoms were minor and resolved within a few days. The remaining 5 patients (0.1%) who had complained the symptoms immediately after emergence from anesthesia had residual symptoms. CONCLUSIONS: In our hospital, the frequency of neuropathy in the upper extremities was 0.7%. The majority of the neuropathies, however, were minor. Neuropathies persisting for a long time were infrequent complications (0.1%).

Adult↗

[Effectiveness of potassium adsorption filter during intraoperative blood transfusion in patients with chronic renal failure].

Two patients with chronic renal failure on hemodialysis, received rapid transfusion of packed red blood cells (PRBCs) because of massive intraoperative bleeding. To eliminate the excessive potassium in PRBCs, a potassium adsorption filter (Kawasumi KPF-4, Kawasumi Laboratories, INC., Tokyo, Japan) was applied during surgery. The potassium adsorption filter successfully reduced the potassium concentration from 14.4-22.0 mEq x l(-1) to 1.9-3.7 mEq x l(-1). A potassium adsorption filter is a simple and useful alternative for removal of excessive potassium in PRBCs.

Adsorption↗

Addition of 0.1% bupivacaine to buprenorphine and droperidol in patient-controlled epidural analgesia improved postoperative pain scores on coughing after gynecological surgery.

STUDY OBJECTIVE: To compare the analgesic efficacy of additional 0.1% bupivacaine to patient-controlled epidural analgesia (PCEA) using buprenorphine and droperidol after gynecological surgery. DESIGN: Randomized, double-blinded study. SETTING: Operating theater and general ward at Jichi Medical School Hospital. PATIENTS: Thirty patients with American Society of Anesthesiologists physical status I and II scheduled for gynecological surgery. INTERVENTIONS: Patients received combined general and epidural anesthesia for surgery and epidural analgesia for postoperative analgesia. Patients were assigned to receive PCEA with or without 0.1% bupivacaine. Group 1 (n = 15) received buprenorphine 20 microg and droperidol 0.1 mg diluted with saline, and group 2 (n = 15) received bupivacaine 2 mg, buprenorphine 20 microg, and droperidol 0.1 mg diluted with saline (0.1% bupivacaine solution) in a bolus dose of the PCEA, respectively. No background epidural infusion was used. MEASUREMENTS: Visual analog pain scale (VAPS) scores at rest and on coughing, and cumulative frequency of self-administrated analgesic solution in PCEA were recorded at 24 and 48 hours postoperatively. MAIN RESULTS: There were no significant differences noted between the groups in VAPS scores at rest or in cumulative volumes of PCEA solution in 24 or 48 hours postoperatively. Median VAPS scores on coughing in group 2 were significantly lower than those values in group 1 at 24 hours (36 vs 65 mm, P < .001) and 48 hours (32 vs 54 mm, P = .036) postoperatively. CONCLUSIONS: Addition of 0.1% bupivacaine to PCEA using buprenorphine and droperidol provides better analgesia on coughing after gynecological surgery.

Adult↗

[The effect of colored syringes and a colored sheet on the incidence of syringe swaps during anesthetic management].

BACKGROUND: Syringe swap is an important problem in anesthetic care, causing harm to patients. We examined the effect of colored syringe and a colored sheet on the incidence of syringe swaps during anesthetic management. METHODS: We determined the color code. The blue-syringe contains local anesthetics; yellow-syringe, sympathomimetic drugs; and white-syringe with a red label fixed opposite the scale, muscle relaxants. The colored sheet displays the photographs of the syringe with drug name, dose and volume. The colored syringe and colored sheet were supplied for use from February 2004. We compared the incidence of syringe swaps during the period from February 2004 to January 2005 with that from February 2003 to January 2004. RESULTS: Although five syringe swaps were recorded from February 2003 to January 2004, in 5901 procedures, we encountered no syringe swaps from February 2004 to January 2005, in 6078 procedures. The colored syringe and colored sheet significantly decreased the incidence of syringe swaps during anesthetic management (P <0.05). CONCLUSIONS: The use of the sheet together with colored syringes can prevent syringe swaps during anesthesia.

Anesthesiology↗

[Combined spinal epidural anesthesia for emergency cesarean section].

BACKGROUND: We performed a retrospective analysis to evaluate the usefulness of combined spinal epidural anesthesia (CSEA) in emergency cesarean section compared with conventional spinal anesthesia. METHODS: A retrospective chart analysis of patients who had undergone emergency cesarean section over a 7 year period was performed. We extracted at random 150 patients planned by spinal anesthesia, and 150 patients planned by separate-needle CSEA. Patient's data were gathered and analyzed according to the anesthetic technique used. RESULTS: There were no significant differences between the two groups in age, weight, and BMI. Although the time to incision and the time to delivery were significantly faster in spinal anesthesia group than in CSEA group, there was no significant difference in Apgar score between the groups. Moreover, failure of anesthesia and post-dural puncture headache were higher in spinal group than in CSEA group. CONCLUSIONS: CSEA is useful as anesthesia for an emergency cesarean section.

Adult↗

[Ropivacaine-induced grand mal convulsion after obturator nerve block].

We describe a patient to whom ropivacaine 150 mg had been administered during obturator nerve blockade and developed grand mal convulsions because of inadvertent i.v. injection. Venous blood samples were taken 15, 32 and 52 min after the convulsion. The measured total plasma concentrations of ropivacaine were 4.5, 3.5 and 2.9 microg x ml(-1) respectively. The peak plasma concentration at the time of the inadvertent i.v. injection was estimated to be 6.6 microg x ml(-1). The patient recovered uneventfully.

Adult↗

[Outsourcing of anesthesia support system].

BACKGROUND: Recently, the deficiency in anesthesiologist's man power became a social problem in Japan. Therefore, we tried outsourcing of anesthesia support system. METHODS: The questionnaire was sent to anesthesiologists after an anesthesia support system had started. RESULTS: All anesthesiologists answered reduction in the burden of work. CONCLUSIONS: Anesthesia support system outsourcing is effective in reducing the workload of anesthesiologists.

Anesthesiology↗

[Postintubation granuloma of the larynx].

A 50-year-old woman underwent tonsillectomy under general anesthesia. She developed progressive hoarseness two month after the tonsillectomy, and a large granuloma of the larynx was found. Surgical removal of the granuloma was performed by laryngo-microsurgery. We should keep in mind that postintubation granuloma of the larynx might develop after tracheal intubation, and careful airway manipulation is needed to avoid this potential complication.

Anesthesia, General↗

[Evaluation of 100 anesthetic incidents].

BACKGROUND: The anesthetic incident-reporting scheme in the department of anesthesia, Jichi Medical School Hospital, has been running for 3 years and 100 incidents have now been reported. METHODS: An 'anesthetic incident' was defined as any incident related to anesthesia which either caused harm, or if uncorrected might have caused harm, to a patient. RESULTS: There were 26 problems involving drugs, 18 airway and respiratory problems, 15 dental damages, 11 cardiovascular problems, 8 problems related epidural anesthesia, and 22 others. CONCLUSIONS: The scheme has successfully highlighted weaknesses of the department.

Anesthesia↗

[Comparison of pharmacokinetics of saquinavir soft-gel capsule (SQV-SGC) combined with ritonavir (RTV), SQV hard-gel capsule with RTV, and SQV-SGC alone].

Saquinavir (SQV) is a human immunodeficiency virus (HIV) specific protease inhibitor. When combined with ritonavir (RTV), plasma concentration of SQV is increased. In this study, we examined pharmacokinetics of SQV soft-gel capsule (SQV-SGC) 400 mg twice daily (BID) combined with RTV in HIV-1-infected patients (n = 4) and compared with those of SQV hard-gel capsule (SQV-HGC) 400 mg BID combined with RTV (n = 12). Pharmacokinetics of SQV-SGC 1,200 mg single dose in healthy subjects (n = 10) were also studied. Peak SQV concentration in plasma (Cmax) and area under the plasma concentration-time curve from 0 to 8 hour (AUC0-8 h) of SQV-SGC 400 mg BID combined with RTV group were higher than those of SQV-HGC 400 mg BID combined with RTV group; increase of 14.7% and 25.5%, respectively. Cmax and AUC0-8 h of SQV-SGC were higher than SQV-SGC 1,200 mg single dose group; increase of 3.9 fold and 8.5 fold, respectively. These results indicated that SQV-SGC combined with RTV therapy is the most potent antiviral effect among SQV-SGC with RTV, SQV-HGC with RTV, and SQV-SGC alone.

Anti-HIV Agents↗

[Heparin resistance during cardiopulmonary bypass].

A 74-year-old man was scheduled for coronary artery bypass graft surgery with cardiopulmonary bypass. After intravenous heparin (200 U.kg-1), the activated clotting time (ACT) increased from 124 to 436 sec. However, it decreased to 128 sec immediately after cardiopulmonary bypass. The bypass was discontinued because the addition of heparin (200 U.kg-1) proved heparin resistance. The coronary artery bypass procedure was completed uneventfully without cardiopulmonary bypass. Several recent articles have reported that heparin resistance was corrected with antithrombin III concentrates, fresh frozen plasma, or argatroban. In this case, these drugs could not be used because the mechanism of heparin resistance remains uncertain. Thus, the off-pump technique is useful for unknown heparin resistance.

Aged↗

[Retroperitoneal emphysema during total hip replacement].

A 55-year-old woman with rheumatic arthritis was scheduled for total hip replacement. The procedure was performed under combined spinal and epidural anesthesia. Intraoperatively, the part of acetabular roof was cracked by reaming the region but she did not complain of any symptom. However, during pulse irrigation she complained of abdominal pain. After the operation, abdominal distension was noticed and retroperitoneal emphysema was disclosed. She was managed in a ward without problems postoperatively.

Anesthesia, Epidural↗