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Dive into the research topics where Nobuyuki Taenaka is active.

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Featured researches published by Nobuyuki Taenaka.


Critical Care Medicine | 1992

An initial comparison of intensive care in Japan, and the United States

Carl A. Sirio; Kimitaka Tajimi; Choichiro Tase; William A. Knaus; Douglas P. Wagner; Hiroyuki Hirasawa; Nobue Sakanishi; Hirotada Katsuya; Nobuyuki Taenaka

ObjectiveThe objective of this study was to compare the utilization of, and outcome from, critical care services in selected medical centers providing secondary and tertiary care in the United States and Japan. DesignProspective data collection on 1,292 patients from each of the participating Japanese study hospitals in 1987 to 1989 and compared with the 5,030 patients in the United States 1982 Acute Physiology and Chronic Health Evaluation (APACHE II) database used to develop the APACHE II equation. Detailed organizational characteristics of the participating ICUs and hospitals were also obtained. SettingData collection took place in the ICUs of 13 U.S. hospitals and six Japanese hospitals. PatientsData were collected on consecutive, unselected patients from medical, surgical, and mixed medical/surgical critical care units, with a spectrum of medical and surgical diagnoses. Measurements and Main ResultsU.S. and Japanese ICUs have a similar array of diagnostic and therapeutic modalities. Only 2% (range 0.6 to 3.5) of beds in Japanese hospitals were designated to intensive care. The organization of the Japanese and U.S. ICUs varied by hospital. There were significantly fewer women admitted to Japanese ICUs and a substantially lower proportion of low-risk-of-death patients. Despite a rapidly aging population, there were relatively fewer elderly patients with chronic health ailments in the Japanese ICU population (8%) compared with the U.S. cohort (18%). ConclusionsIn this sample of hospitals, similar high-technology critical care is available in the United States and Japan. Variations in utilization between the two countries represent differences in case mix and bed availability. The APACHE II equation stratified patients in the Japanese patient cohort across the full spectrum of increasing severity of illness.


Anesthesia & Analgesia | 1997

Ocular Surface Disorders in the Critically Iii

Hideaki Imanaka; Nobuyuki Taenaka; Junko Nakamura; Keiko Aoyama; Hisashi Hosotani

Abnormalities of the cornea and conjunctiva occur in association with neurological diseases, nocturnal lagophthalmos, coma, infection, and mechanical ventilation.We investigated the incidence and causes of ocular surface disorders in critically ill patients. In a retrospective study, the presence of conjunctivitis and corneal erosion was determined by reviewing the medical charts of 143 mechanically ventilated patients (intensive care unit [ICU] stay >or=to7 days). In the subsequent prospective study, 15 patients who had sedatives or muscle relaxants administered continuously for more than 48 h in the ICU were investigated. Corneal erosion was examined using a slit lamp once a day. Ocular surface disorder was found in 28 of the 143 patients (20%) whose ICU stay exceeded 7 days. The incidence increased with continuous sedation (35% vs 15%). The incidence also increased with continuous neuromuscular blockade (39% vs 11%). In the prospective study, nine patients (60%) developed corneal erosion. A patients inability to fully close his or her eyes increased the incidence (P < 0.01) of corneal erosion. Protective eyelid taping was effective in preventing and treating the corneal erosion. In conclusion, the critically ill often develop ocular surface disorders, especially when sedated and immobilized. A close relationship was observed between these conditions and the inability to close ones eyes. (Anesth Analg 1997;85:343-6)


Critical Care Medicine | 1989

Effects of norepinephrine on renal function in septic patients with normal and elevated serum lactate levels

Toshio Fukuoka; Masaji Nishimura; Hideaki Imanaka; Nobuyuki Taenaka; Ikuto Yoshiya; Jun Takezawa

Effects of iv norepinephrine (NE) on renal function were investigated retrospectively in 15 patients with hyperdynamic septic shock. All patients had either a low systolic BP less than 80 mm Hg, and/or oliguria less than 0.5 ml/kg-h. We examined their serum creatinine level (SCr), daily urine flow (UF), 24-h creatinine clearance (Ccr), and hemodynamic indices before and during NE infusion. Before NE administration, the patients were divided into those with with a serum lactate level (Lac) less than 20 mg/dl (group A, n = 9) and greater than 20 mg/dl (group B, n = 6). NE was infused continuously at rates between 0.05 and 0.24 microgram/kg.min which increased systolic BP by greater than or equal to 20 mm Hg. Cardiac index was not significantly changed in either group. In group A, NE increased both UF (p less than .05), and systemic vascular resistance index (SVRI) (p less than .01), but did not affect Ccr. In group B, NE did not increase UF nor SVRI, and decreased Ccr significantly (p less than .05). It is concluded that NE increased UF and SVRI only when Lac was in normal range; otherwise, NE reduced renal function. Thus, when administering NE to increase UF, both Lac and renal function should be monitored carefully.


Critical Care Medicine | 1983

Gabexate mesilate (FOY) therapy of disseminated intravascular coagulation due to sepsis.

Nobuyuki Taenaka; Yasuhiro Shimada; Takahiko Hirata; Masako K. Nishijima; Jun Takezawa; Ikuto Yoshiya; Junichi Kambayashi

Gabexate mesilate (FOY), a synthetic serine proteinase inhibitor, has an anticoagulant activity in the absence of antithrombin-III. We investigated FOY therapy for the treatment of disseminated intravascular coagulation (DIC) associated with sepsis in 15 patients (group F), and compared it with heparin therapy in 8 patients (group H). Successful treatment was observed in 13 patients in group F and in 4 patients in group H. The efficacy of the therapy in both groups was not significantly different. However, in patients whose antithrombin-III values were less than 20 mg/dl at the initiation of the therapy, FOY therapy was successful in 6 of 7 patients, whereas heparin therapy was not at all successful in 4 patients (p < 0.05). We conclude that FOY can be used as effectively as heparin for the treatment of DIC, and that FOY therapy is superior to heparin therapy in DIC associated with decreased antithrombin-III.


Critical Care Medicine | 1982

Circulatory responses to afterloading with phenylephrine in hyperdynamic sepsis.

Toji Yamazaki; Yasuhiro Shimada; Nobuyuki Taenaka; Oshumi H; Jun Takezawa; Ikuto Yoshiya

We assessed cardiac function by acute pressure loading with phenylephrine in 7 patients who had hyperdynamic sepsis and in 8 patients who had heart disease. All patients with sepsis had a positive Limulus lysate test, a septic focus, and a cardiac output (CO) greater than 6.0 L/min. Phenylephrine was given iv to elevate systolic arterial pressure by 30 mm Hg. Cardiac index (CI) and stroke index (SI) increased significantly in patients with hyperdynamic sepsis, whereas systemic vascular resistance index (SVRI) showed no change. In patients with heart disease, CI and SI decreased significantly, whereas SVRI increased significantly. The marked differences in response to phenylephrine by the two groups suggest lack of cardiac dysfunction in patients with hyperdynamic sepsis.


American Journal of Infection Control | 1999

Handwashing before entering the intensive care unit: What we learned from continuous video-camera surveillance

Shinya Nishimura; Masahiro Kagehira; Fusae Kono; Masaji Nishimura; Nobuyuki Taenaka

Handwashing is one of the most important factors in controlling the spread of bacteria and in preventing the development of infections. This simple procedure does not have a high compliance rate. The Association for Professionals in Infection Control and Epidemiology, Inc, guideline recommends that hands must be washed before and after patient contact. In our intensive care unit (ICU), we have made it a rule that everyone should wash their hands before entering the ICU. The purpose of this study was to ascertain the handwashing compliance of all personnel and visitors to the ICU. A ceiling-mounted video camera connected to a time-lapse video cassette recorder recorded each persons actions when they entered the ICU during a 7-day period. Handwashing compliance was assessed for 3 different categories: ICU personnel, non-ICU personnel, and visitors to patients. There were 1030 entries to the ICU during the observation period. ICU personnel complied with handwashing in 71% of entries, non-ICU personnel in 74% of entries, and visitors to patients in 94% of entries. Handwashing compliance by visitors to patients was significantly higher than among personnel (P <.001). Handwashing compliance among personnel before entering the ICU was low. Continuous effort is needed to raise awareness of the handwashing issue, not only to ensure compliance with APIC recommendations but also in our facility, to ensure that health care personnel wash their hands on entry to the ICU.


Anesthesia & Analgesia | 1998

The influence of surgical stress on T cells : Enhancement of early phase lymphocyte activation

Motomu Shimaoka; Kikumi Hosotsubo; Masahiro Sugimoto; Gaku Sakaue; Nobuyuki Taenaka; Ikuto Yoshiya; Hiroshi Kiyono

For the control of postoperative infection, it may be important to understand the possible influences of surgical stress on the host immune system.To this end, we examined how the early phase of lymphocyte activation was affected in patients after major surgery (eight patients with esophageal carcinoma and six undergoing cardiac surgery) using a flow cytometric assay based on expression of the early activation antigen, CD69. Freshly isolated T cell in preoperative and postoperative samples did not express CD69. When peripheral blood mononuclear cells were stimulated in vitro, the expression of CD69 was greatly enhanced in both CD4 and CD8 T cells, compared with the preoperative samples. The proportion of de novo CD69-expressing cells in the CD4 subset was approximately 3 times (Postoperative Day 1) and 4 times (Postoperative Days 2, 3, 5, and 7) greater than those preoperatively, whereas the proportion of de novo CD69-expressing cells in the CD8 subset was approximately 1.5 times (Postoperative Days 2 and 5) and 2 times (Postoperative Day 3) greater than those preoperatively. The proportion of CD69+ cells was significantly greater in the CD4+ subset than in the CD8+ subset during the postoperative period. Implications: Our results show that major surgical stress enhances the early phase of lymphocyte activation. The augmentation of activation was greater in CD4 (helper) T cells than in CD8 (cytotoxic) T cells. (Anesth Analg 1998;87:1431-5)


Anesthesiology | 1995

Thoracic Epidural Anesthesia Attenuates Halothane-induced Myocardial Sensitization to Dysrhythmogenic Effect of Epinephrine in Dogs

Takahiko Kamibayashi; Yukio Hayashi; Atsushi Yamatodani; Nobuyuki Taenaka; Ikuto Yoshiya

Background The autonomic nervous system plays a critical role in the central modulation of cardiac dysrhythmias. Because sympathetic blockade by thoracic epidural anesthesia has been documented to protect patients from various stress responses, the authors speculate that epidural anesthesia can attenuate the dysrhythmogenic interaction between halothane and epinephrine. Methods In adult mongrel dogs anesthetized with halothane, the dysrhythmogenic dose (DD) of epinephrine, defined as the smallest dose producing four or more premature ventricular contractions within a 15-s period, was determined in the presence of thoracic epidural mepivacaine or saline. To address the effect of circulating mepivacaine after epidural administration, the authors examined the DD of epinephrine in the presence of intravenous mepivacaine. They also investigated the effect of thoracic epidural anesthesia in bilaterally vagotomized dogs. Results Epidural mepivacaine significantly increased the DD of epinephrine compared with epidural saline. However, intravenous mepivacaine did not affect the DD of epinephrine, even when the plasma concentration of mepivacaine during the dysrhythmias was twice that in the epidural mepivacaine group. The beneficial effect of epidural mepivacaine was not seen in bilaterally vagotomized dogs. Conclusions Thoracic epidural anesthesia attenuated the myocardial sensitization by halothane, and vagal activity had an essential role in this action.


Brain Research | 1997

Inhalation anesthetics suppress the expression of c-Fos protein evoked by noxious somatic stimulation in the deeper layer of the spinal cord in the rat

Satoshi Hagihira; Nobuyuki Taenaka; Ikuto Yoshiya

The effects of inhalation anesthetics, nitrous oxide (N2O) and halothane, on the expression of c-Fos protein evoked by formalin injection were studied in the spinal cord in the rat. The expression of c-Fos protein was detected by immunocytochemistry following the injection of formalin (5%, 100 microliters) into the plantar surface of the left hindpaw. After 15 min of halothane (F) anesthesia, the anesthetics was switched to 40% or 70% of N2O, 0.5% or 1.5% of F or room air (for control) immediately following the formalin injection. Two hours later the rats were sacrificed and perfused. Sections of the L4 level of spinal cord were immunostained with anti c-Fos antibody. We counted the number of Fos-like immunoreactive (FLI) cells in every specific lamina as follows: superficial layer (laminae I and II), nucleus proprius (laminae III and IV), neck of the dorsal horn (laminae V and VI) and ventral gray (laminae VII-X). Then we compared the results of each category of sample. Both N2O and halothane suppressed the expression of c-Fos in the neck of the dorsal horn and ventral gray in a dose-dependent manner, but no effects were seen at the superficial layer or nucleus proprius. Suppression of c-Fos expression was greater under N2O than halothane anesthesia. This finding suggests that N2O had a stronger analgesic effect than halothane. The current study indicates that inhalation anesthetics do not act equally on every kind of spinal neurons. Both N2O and halothane have effects on spinal neurons in the deeper layers but not on the neurons existed in laminae I-II, some of which directly receive noxious inputs. Pretreatment with 2 mg/kg of naloxone, which completely reversed the effects of morphine, did not alter the effect of 70%N2O, suggesting that the analgesic effect of N2O is not mediated by an intrinsic opioid mechanism at the spinal cord level.


Journal of Pineal Research | 1998

Circadian secretion patterns of melatonin after major surgery

Shinya Nishimura; Yuji Fujino; Motomu Shimaoka; Satoshi Hagihira; Nobuyuki Taenaka; Ikuto Yoshiya

Abstract: Biorhythms, such as regular variation in core body temperature and the pattern of the secretion of melatonin, are thought to be mediated by the same biological clock. Core body temperature is affected by the inflammatory response to major surgery. Apart from the well‐known inhibitory effect of bright light on its secretion, melatonin is an exceedingly good marker of one of the central generating systems of circadian rhythms. We sequentially measured the plasma melatonin concentration pattern in patients who had undergone esophagectomy with thoracotomy to elucidate the circadian rhythm after major surgery. From seven patients who had received esophagectomy with thoracotomy for esophageal cancer, plasma concentrations of melatonin were measured using an RIA method. Blood samples were collected via each patients arterial line at 00.00, 02.00, 04.00, 06.00, 08.00, 12.00, 16.00, 20.00, and 24.00 hr on the first postoperative day for six of the patients, and, for one patient, every 2 hr until the third postoperative day and every 4 hr thereafter until the sixth postoperative day. Four patients out of seven had melatonin concentrations of over 30 pg/ml (mean 34 pg/ml) at 24.00 hr on the first postoperative day. Five patients showed circadian secretion patterns of melatonin during the first postoperative day. One patient whose melatonin concentrations were measured consecutively for 6 days showed a regular circadian secretion pattern through the 6 days of the study. Even the stress caused by extremely invasive surgery did not significantly disturb the melatonin secretion pattern.

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