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N Taenaka

Publications and source records attributed to N Taenaka.

At least 19 recordsLinked to original sources
PubMed2002

Actigraphic assessment of the preoperative hypnotic effects of brotizolam and zopiclone.

Brotizolam and zopiclone have a common ability to bind to the benzodiazepine recognition site and have been used as useful preoperative hypnotics. The aim of the present study was the quantitative evaluation of the preoperative hypnotic effects of brotizolam and zopiclone by actigraphy. Forty patients received brotizolam 0.25 mg (group B) or zopiclone 7.5 mg (group Z) in randomized manner at 21:30 on the night before surgery. Sleep and awake was identified by wrist activity measured with a motion-logger actigraph. Sleep time was assessed in total period from 22:00 to 6:00 and its 4 subdivided 2-hour periods (22:00-24:00, 24:00-2:00, 2:00-4:00, 4:00-6:00). The total sleep time in group B (448 +/- 23 min) was significantly longer than that in group Z (416 +/- 43 min). Group Z showed a significant reduction in sleep time in period 4 (4:00-6:00), compared with other periods, whereas group B did not show any difference among 4 periods. In comparison of each period between 2 groups, group B showed significant longer sleep time in period 4. An actigraphic assessment of sleep time has demonstrated the quantitative difference of the effects of brotizolam and zopiclone as preoperative hypnotics.

Adult↗
PubMed2001

Glucocorticoid suppresses neutrophil activation in ventilator-induced lung injury.

OBJECTIVE: To investigate, in a rat model, the role of the Mac-1/ICAM-1 pathway and the anti-inflammatory activity of steroid in ventilator-induced lung injury. DESIGN: Prospective, randomized controlled study. SETTING: Animal investigation using Wistar rats. INTERVENTION: Rats in three randomly assigned groups of 18, a total of 54 animals, were subject to the following: Two groups received high peak inspiratory pressure (35 cm H2O) ventilation after pretreatment with methylprednisolone (high-methylprednisolone group) or pretreatment with methylprednisolone vehicle (high-vehicle group). The third group of animals received low peak inspiratory pressure (7 cm H2O) ventilation after pretreatment with methylprednisolone vehicle (low-vehicle group). Except for animals previously killed to establish baseline values, after 40 mins of mechanical ventilation, the animals in each group were killed. Some animals provided histological samples, and the rest received total lung lavage. MEASUREMENT: We measured flow cytometry of lavage fluid, cell counts of tissue samples, and pressure-volume curves before and after mechanical ventilation. RESULTS: In the groups that received high peak inspiratory pressure ventilation, both the number of neutrophils that infiltrated the lungs and the expression of Mac-1 and ICAM-1 on neutrophils and macrophages increased significantly more than in the low-vehicle group. Static lung compliance was reduced in the high peak inspiratory pressure groups. In the high peak inspiratory pressure groups, there were significantly fewer neutrophils in samples from the high-methylprednisolone group (0.412 +/- 0.1 x 10(5)) than from the high-vehicle group (1.10 +/- 0.1 x 10(5); p < .05). The high-vehicle group showed greater expression of CD11b on neutrophils, but this was significantly decreased by methylprednisolone (mean fluorescence intensity: high-vehicle, 118.4 +/- 34.3; high-methylprednisolone, 25.8 +/- 4.2; p < .05). The lung mechanics measured by pressure-volume curve analysis were deteriorated less in the high-methylprednisolone group. CONCLUSION: Our study suggests that a neutrophil-endothelium interaction via the Mac-1/ICAM-1 pathway is involved in the activation and recruitment of neutrophils in ventilator-induced lung injury. Activation and recruitment of neutrophils were lessened by pretreatment with methylprednisolone, which might have contributed to the improvement of lung dysfunction after mechanical ventilation.

Animals↗
PubMed2001

Relationship between work of breathing provided by a ventilator and patients' inspiratory drive during pressure support ventilation; effects of inspiratory rise time.

Inspiratory drive and work of breathing provided by a ventilator (WOBv) during pressure support ventilation (PSV) were examined in 15 patients. At PSV 10 and 15 cm H2O during CPAP 5 cm H2O, patients with low P0.1 (<4.2 cm H2O, n=9) showed WOBv 0.57 and 0.92 J/l, those with high P0.1 (>4.2 cm H2O, n=6) showed 0.31 and 0.62 J/l respectively. WOBv was smaller and pressure-time product of oesophageal pressure (PTP) was significantly larger in high P0.1 patients. Peak inspiratory flow for low P0.1 patients increased as PSV level increased but high P0.1 patients showed no significant change. In a lung model, effects of inspiratory rise time (IRT) and PSV were studied at high and low inspiratory drives by using ventilators with (Servo 300) and without (Mallinckrodt 7200a) adjustable IRT. With 7200a, PSV 10 cm H2O during low drive was compared with PSV 10 and 15 cm H20 during high drive. In Servo 300, PSV 10 cm H2O (IRT 0.6 and 0.0 sec) during low drive was compared with PSV 10 cm H20 (IRT 0.6 and 0.0 sec) and PSV 15 cm H2O (IRT 0.6 sec) during high drive. Raising PSV and shortening IRT both increased peak inspiratory flow. Initial inspiratory flow increased in inverse proportion to IRT, but higher PSV had a little effect. WOBv with high drive was less than with low drive. Higher PSV preserved WOBv by increasing tidal volume. Shortening IRT recruited WOBv by increasing initial inspiratory flow without changing airway pressure and tidal volume. Compared with higher PSV, shorter IRT reduced PTP more. In conclusion, WOBv decreased as inspiratory drive increased due to inability to increase inspiratory flow. Increasing initial inspiratory flow was more effective than raising PSV to preserve inspiratory assistance of PSV at high inspiratory drive.

Adult↗
PubMed2000

Infrared transmission of electronic information via LAN in the operating room.

Recent advances in technology have brought many kinds of monitoring devices into the operating room (OR). The information gathered by monitors can be channeled to the operating ward information system via a local area network (LAN). Connecting patients to monitors and monitors to the LAN, however, requires a large number of cables. This wiring is generally inconvenient and particularly troublesome if the layout of the OR is rearranged. From this point of view, wireless transmission seems ideally suited to clinical settings. Currently, two modes of wireless connectivity are available: radio-frequency (RF) waves or infrared (IR) waves. Some reports suggest that RF transmission is likely to cause electromagnetic interference (EMI) in medical devices such as cardiac pacemakers or infusion pumps. The risk of malfunctioning life-sustaining devices and the catastrophic consequences this would have on seriously ill patients rules out the use of RF. Here, we report an IR system using IR modems for LAN connectivity in the OR. In this study, we focused on the possible detrimental effects of EMI during wireless connectivity. In our trial, we found no evidence of EMI of IR modems with any of the medical devices we tested. Furthermore, IR modems showed similar performance to a wired system even in an electrically noisy environment. We conclude that IR wireless connectivity can be safely and effectively used in ORs.

Hospital Information Systems↗
PubMed2000

Does blood type B protect against haemolytic uraemic syndrome? An analysis of the 1996 Sakai outbreak of Escherichia coli O157:H7 (VTEC O157) infection. The Osaka HUS Critical Care Study Group.

OBJECTIVES: Expression of the P1 blood type antigen is suggested to have a protective effect against post-enteropathic haemolytic uraemic syndrome (HUS). The B blood type may also protect against HUS, since terminal trisaccharide sequences similar to those of the B blood type determinants are reported to have an affinity to Vero cytotoxin that is 23% as strong as that of the P1 determinants. Thus, we studied whether ABO blood types were related to the occurrence or severity of HUS. METHODS: We obtained clinical and laboratory data of 49 HUS patients treated in 14 critical care facilities during the 1996 Escherichia coli O157:H7 outbreak in Sakai, Japan. We retrospectively studied whether ABO blood types were related to the occurrence or severity of HUS. RESULTS: The numbers of patients with blood types A, B, O or AB were 29, 8, 12, and 0, respectively. For each blood type, the number of patients with severe renal complications was 16, 6, 9, and 0, respectively. The distribution of blood types among the HUS patients deviated from a population-based distribution of blood types (P<0.05, Chi-squared test); i.e., the frequency of the A blood phenotype was significantly higher among our HUS patients. However, there was no significant difference in the frequency of patients with the A antigen (A and AB blood groups) among our HUS patients, whereas the frequency of B antigen expression was significantly lower (P<0.05, Chi-squared test). The risk of severe renal complications did not appear to be related to ABO blood types. CONCLUSIONS: Our data suggest that expression of the B antigen has a protective effect against the onset of HUS, but that it does not affect the severity of the disease.

ABO Blood-Group System↗
PubMed2000

Optimal level of pressure support ventilation for recovery from diaphragmatic fatigue in rabbits.

OBJECTIVE: To determine whether there is an optimal level of pressure support ventilation (PSV) for recovery from acute diaphragmatic fatigue. DESIGN: Prospective laboratory trial. SETTING: Experimental laboratory. SUBJECTS: Twenty healthy adult New Zealand White rabbits. INTERVENTIONS: Diaphragmatic fatigue was induced with 50 Hz of phrenic nerve stimulation for 30 mins. Recovery was compared between inspiratory load + PSV of 0 cm H2O (L0), inspiratory load + PSV of 60 cm H2O (L60), inspiratory load + PSV of 80 cm H2O (L80), and PSV of 0 cm H2O without inspiratory load (SB) for 90 mins immediately after the end of the fatigue-inducing procedure. To add inspiratory load during the recovery phase, three pressure threshold valves, each having an opening pressure of -20 cm H2O, were used. MEASUREMENTS AND MAIN RESULTS: After the fatigue-inducing procedure, diaphragmatic electromyogram and transdiaphragmatic pressure remained at baseline in both SB and L60, decreased in L80, and increased in L0. Recovery was assessed by abdominal cavity pressure (Pabd) generated by high-frequency (100 Hz) and low-frequency (20 Hz) stimulation. Pabd at 100 Hz recovered to baseline in L60 and SB but not in L0 and L80 (69.1%, 81.3%, 100.3%, and 100.7% of the baseline at 90 mins for L0, L80, L60, and SB, respectively). Pabd at 20 Hz did not differ among ventilatory settings. CONCLUSION: There is an optimal range of PSV assist level to improve recovery from diaphragmatic fatigue. Recovery was hampered not only by inadequate PSV but also by excessive PSV.

Airway Resistance↗
PubMed2000

[Successful weaning from mechanical ventilation in an infant with congenital tracheal stenosis and bronchial malacia using endobronchial stent, nasal CPAP and continuous sedation].

A 1.9 kg male infant who showed respiratory distress at his birth, was diagnosed by bronchoscopy as having congenital segmental stenosis of trachea with complete ring. Tracheoplasty was performed and the infant was admitted to ICU. After admission to ICU, we suspected the residual tracheal stenosis and the left main bronchial malacia by bronchoscopy. Although we tried to wean him from mechanical ventilation, but failed and re-intubated him four times because of marked respiratory acidosis after extubation. Bronchoscopy was performed repeatedly, and the residual tracheal stenosis and the left main bronchial malacia were apparent. After patch tracheoplasty of the costal cartilage to the residual tracheal stenosis and implantation of angioplastic expandable metallic stent to the left main bronchus, he was successfully extubated under continuous sedation. In addition, nasal CPAP was effective to reduce retraction and wheezing after extubation. He was discharged from ICU on the 183rd ICU day.

Bronchi↗
PubMed1999

Dynamic measurement of intrinsic PEEP does not represent the lowest intrinsic PEEP.

OBJECTIVE: Dynamic intrinsic PEEP (PEEPi-dyn) is the airway pressure required to overcome expiratory flow and is considered to represent the lowest regional PEEPi. However, there are few data to validate this assumption. We investigated if PEEPi-dyn represents the lowest PEEPi. SETTING: The animal laboratory at the Osaka University Medical School. MEASUREMENTS AND RESULTS: We compared static PEEPi (PEEPi-stat) and PEEPi-dyn in healthy animals. Five adult white rabbits (2.77+/-0.05 kg) were anesthetized, tracheostomized, and intubated with several different sizes of endotracheal tubes (ETT) (2.0, 2.5, 3.0, 3.5, or 4.0 mm i.d.). The animals were paralyzed and ventilated (Siemens Servo 900C). Baseline ventilator settings were at a rate of 50/min, inspiratory:expiratory (I:E) ratio of 2:1 or 4:1, and minute ventilation was manipulated to create 3 or 5 cm H2O PEEPi-stat. PEEPi-stat was measured using the expiratory hold button of the ventilator. PEEPi-dyn showed large variations. In all ventilator settings, PEEPi-dyn was higher than PEEPi-stat (p<0.001). The larger the ETT, the higher the PEEPi-dyn at an I:E ratio of 2:1 (p<0.05). The higher the minute ventilation, the greater the difference between PEEPi-stat and PEEPi-dyn. The tidal volume and the difference showed a significant correlation (r2 = 0.514, p<0.001). CONCLUSIONS: The value of PEEPi-dyn was dependent on ventilatory settings, and PEEPi-dyn does not necessarily represent the lowest regional PEEPi within the lungs.

Animals↗
PubMed1999

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

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 person's 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.

Guideline Adherence↗
PubMed1999

Earlier prediction of anastomotic insufficiency after thoracic esophagectomy by intramucosal pH.

OBJECTIVES: To assess the value of using intramucosal pH (pHi) measurements to evaluate the viability of the gastric tube after thoracic esophagectomy, and to determine whether these measurements may be used for early prediction of anastomotic insufficiency. DESIGN: Prospective, observational study. SETTING: University hospital in Japan. PATIENTS: Thirty-nine patients who had undergone thoracic esophagectomy as a treatment for esophageal cancer. INTERVENTIONS: The blood flow within the gastric tube was measured using a laser Doppler flowmeter during surgery. Periodic measurement of the pHi within the gastric tube (gastric pHi) began during surgery and continued until the second postoperative day. In 30 patients, the pHi within the rectum (rectal pHi) was measured simultaneously with the gastric pHi. The patients were divided into two groups: those patients who experienced anastomotic insufficiency constituted the leakage(+) group (n = 13); those patients who did not experience these complications were designated the leakage(-) group (n = 26). MEASUREMENTS AND MAIN RESULTS: The gastric pHi values correlated significantly with simultaneous measurements of the blood flow at the anastomotic site (p < .01). The postoperative gastric pHi values increased gradually in the leakage(-) group but stopped increasing after surgery in the leakage(+) group. The rectal pHi values increased gradually after surgery in both groups. Furthermore, there was a significant difference between the two groups when their gastric pHi values were subtracted from their rectal pHi values from the morning of the first postoperative day until the morning of the second postoperative day (p < .05). CONCLUSIONS: The gastric pHi values well reflected the viability of the gastric tube, especially when combined with the rectal pHi values. By measuring pHi, we can more accurately predict the risk of anastomotic insufficiency earlier after surgery and therefore give those patients who need it additional care to improve the viability of the gastric tube.

Adult↗
PubMed1999

Phlebosclerosis of the colon with positive anti-centromere antibody.

A 56-year-old woman with symptoms of chronic bowel disease presented a peculiar calcification of the mesenteric vein of the ascending to transverse colon on barium enema study. The resected colon was hard and black. Histo-pathologic examinations demonstrated fibrous change of the colon with a calcified and hyaline-deposited mesenteric vein. No cell infiltration was observed. These findings were compatible with phlebosclerosis and also with systemic sclerosis. Positive anti-centromere antibody and Raynaud's phenomenon, hallmarks of a variant systemic sclerosis, the CREST syndrome were observed. We therefore speculated that the pathogenesis of the phlebosclerosis of the colon is related to the CREST syndrome.

Autoantibodies↗
PubMed1999

[Evaluation of mortality of patients admitted to ICU for the last 12 years].

We evaluated mortality of 2689 patients admitted to the Intensive Care Unit, Osaka University Hospital from January, 1987 to December, 1998. The patients were divided into 3 groups. Group A consisted of 1408 patients who underwent cardiovascular surgery, group B, 1082 patients who underwent other surgical procedures and group C, 199 patients who were transferred from the department of medicine. We studied mortality rate, causes of death, correlation between length of ICU stay and mortality rate, and mortality rate among age groups for 12 years. The main causes of death were cardiac failure and sepsis in group A, and respiratory failure and sepsis in group B and C. Mortality rate in each group showed no significant change for the last 12 years. Those who stayed more than 2 weeks in ICU showed a significantly higher mortality rate (p < 0.0001). Thus, length of ICU stay and mortality rate showed a positive correlation (p < 0.0001). The youngest group (age 0-1) showed a significantly higher mortality rate than other age groups (p < 0.0001). As sepsis was the most important cause of death in all the groups, the prevention and treatment of infection are the most important issue in our ICU to reduce mortality rate.

Adolescent↗
PubMed1998

Profiles of circulating inflammatory- and anti-inflammatory cytokines in patients with hemolytic uremic syndrome due to E. coli O157 infection.

The systemic inflammatory response to Escherichia coli O157 infection was studied from the profiles of circulating inflammatory and anti-inflammatory cytokines. Twelve patients transferred sequentially to our hospital for the intensive care with acute illness due to Escherichia coli O157 infection and the possible form of haemolytic uraemic syndrome were included in this study. Increased circulating concentrations of tumour necrosis factor, interleukin 6, interleukin 8, granulocyte colony-stimulating factor, and interleukin 10 were found in patients with various stages of this infection and haemolytic uraemic syndrome. Especially, the degree of the increase of circulating interleukin 10 in those who had a typical signs of haemolytic uraemic syndrome was higher than those of other inflammatory cytokines. Two groups of E. coli infection could be classified into one with a typical haemolytic uraemic syndrome and the other with atypically bacteremic state over haemolytic uraemic syndrome according to these cytokine levels.

Adult↗
PubMed1998

Functional residual capacity measurement during tracheal gas insufflation.

OBJECTIVE: Tracheal gas insufflation (TGI) is considered an adjunctive method to enhance carbon dioxide elimination during permissive hypercapnia in patients with acute respiratory distress syndrome. Due to increasing tidal volume and/or expiratory resistance, TGI may cause intrinsic PEEP (PEEPi), and may lessen the advantages of permissive hypercapnia. There is no reliable method to measure PEEPi during TGI. Using an argon washout method to evaluate dynamic hyperinflation, we developed a method to measure FRC with TGI flow. METHODS: We measured FRC during TGI by washing out both the ventilator and TGI circuit with 100% oxygen (O2) previously equilibrated with 10% argon and 90% O2. To test the accuracy of our system, we measured the volume in a model lung composed of two flasks. The FRC of the model lung was changed by varying its volume of water, to active 500, 1000, and 1500 mL. The change of FRC (deltaFRC) of the model lung was measured at a flow of 0, 4, 8, and 12 L/min. Then the FRC of a bellows-type model lung was measured at the same TGI flow. PEEPi of the model lung was also recorded as the pressure inside the bellows at end-expiration. RESULTS: Our FRC measurements were accurate within 10% except for that of 500 mL without TGI (12.7%+/-1.1%). As inspiratory time (TI) and/or TGI flow increased, the FRC of the bellows-type model lung increased. PEEPi and deltaFRC showed a positive correlation (r = 0.843, p < 0.001). The higher the TGI flow, the greater was the deltaFRC with both continuous and expiratory-phase TGI. FRC during continuous TGI was higher than during expiratory-phase TGI especially during long TI and high TGI flow. CONCLUSIONS: The system developed in this study can be used as a method to detect air-trapping during TGI.

Functional Residual Capacity↗
PubMed1998

Up-regulation of Fas ligand (FasL) mRNA expression in peripheral blood mononuclear cells (PBMC) after major surgery.

FasL, which is expressed mainly on activated lymphocytes, can induce apoptosis (programmed cell death) of cells which express Fas. Fas/FasL interaction is primarily beneficial in maintaining immunological and physiological homeostasis by eliminating unnecessary cells. Dysregulation of the interaction, however, leads to tissue damage. We investigated how Fas/FasL levels changed after major surgery. The major aim of this study was to elucidate the involvement of the Fas/FasL system in postoperative inflammation. The investigation involved 10 patients admitted to the intensive care unit after surgery. Although the percentage of Fas+ cells and the amount of Fas expression tended to increase, there was no significant difference between pre- and post-operative samples. In contrast, the levels of FasL mRNA were dramatically up-regulated after operation. Post-operative C-reactive protein (CRP) levels increased and correlated well with FasL levels (r=0.91, P<0.01). Lymphocyte counts decreased after operation and were inversely proportional to FasL levels (r=0.58, P < 0.05). These results suggest that the enhanced FasL expression is likely to be related to systemic inflammatory responses induced during the perioperative period. FasL up-regulation may be involved in the aggravation of tissue damage, including lymphocytopenia, in the early post-operative period.

Aged↗