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Naoki Aikawa

Publications and source records attributed to Naoki Aikawa.

At least 37 records · Page 2Linked to original sources
PubMed2004

Long-term survival of Japanese patients transported to an emergency department because of syncope.

STUDY OBJECTIVE: Cardiovascular disease mortality is affected by ethnic differences and is lower in Japan than in Western countries. Although patients with cardiac syncope have significantly higher mortality than patients with noncardiac syncope in Western countries, no such phenomenon has been described in Japan. The aim of this study is to clarify the long-term mortality of patients with syncope who are brought to an emergency department (ED) in Japan. METHODS: This retrospective observational study was conducted on patients treated in the ED of Keio University Hospital in Tokyo. Nine hundred twelve consecutive patients who presented with syncope were identified. The patients were classified into 2 groups according to the cause of syncope: cardiac syncope and noncardiac syncope. Follow-up information about mortality was obtained from mailed questionnaires and medical records. Mortality data were analyzed using the actuarial life-table method and a Cox proportional hazards model. RESULTS: Follow-up information was obtained for 715 patients. The median follow-up period was 38 months, during which 63 patients died. At 5 years, the 23.1% (95% confidence interval [CI] 12.7% to 33.4%) mortality of the patients with cardiac syncope was significantly higher than the 8.2% (95% CI 5.5% to 10.9%) mortality of the patients with noncardiac syncope (P<.0001). The incidence of cardiac death among the patients with cardiac syncope was 17.2% (95% CI 7.8% to 26.5%) compared with 0.9% (95% CI 0% to 1.8%) in the noncardiac syncope group (P<.0001). Cardiac syncope was an independent predictor of overall mortality and cardiac mortality (relative risk 2.81 [95% CI 1.53 to 5.16], 18.74 [95% CI 5.90 to 59.52]). CONCLUSION: Cardiac syncope is associated with higher mortality than noncardiac syncope in this Japanese patient population.

Adolescent↗
PubMed2004

Relationship between neutrophil elastase and acute lung injury in humans.

We conducted clinical trials in patients with acute lung injury (ALI) associated with systemic inflammatory response syndrome using a selective neutrophil elastase inhibitor, sivelestat sodium hydrate (Sivelestat), to investigate the involvement of neutrophil elastase in ALI. In the phase III double-blind study (Study 1) in 230 patients, the efficacy of Sivelestat was evaluated with the pulmonary function improvement (PFI) rating as the primary endpoint, and the weaning rate from mechanical ventilator, the discharge rate from intensive care unit (ICU), and the survival rate as secondary endpoints. Afterwards, an unblinded study (Study 2) in 20 patients was conducted using procedures for weaning from mechanical ventilation to reevaluate its efficacy with ventilator-free days (VFD) value, the primary endpoint, and to compare with that of Study 1 subgroup, which met the selection criteria used in Study 2. Sivelestat increased PFI rating, reduced duration of mechanical ventilation, and shortened stay in ICU in Study 1, although there was no significant efficacy on the survival rate. VFD value in Study 2 was comparable to that in the optimal-dose group of Study 1 subgroup, and increase in VFD value correlated with PFI rating and increase in ICU free days. It was concluded that neutrophil elastase may be involved in the pathogenesis of ALI in humans.

Adolescent↗
PubMed2004

Neutrophil depletion attenuates interleukin-8 production in mild-overstretch ventilated normal rabbit lung.

OBJECTIVE: Acute lung injury induced by lung overstretch is associated with neutrophil influx, but the pathogenic role of neutrophils in overstretch-induced lung injury remains unclear. DESIGN: To assess the contribution of neutrophils, we compared the effects of noninjurious large tidal volume (Vt) ventilation on lungs in normal and neutrophil-depleted animals. SETTING: Research animal laboratory. SUBJECTS: Twenty-six male Japanese white rabbits. INTERVENTIONS: Animals were mechanically ventilated for 4 hrs with one of the three following protocols: large Vt (20 mL/kg), small Vt (8 mL/kg), and large Vt (20 mL/kg) with neutrophil depletion achieved by a single dose of vinblastine injection (0.75 mg/kg) intravenously 4 days before the experiment. MEASUREMENTS AND MAIN RESULTS: Large Vt ventilation produced alveolar neutrophil influx compared with low Vt (p =.002) without evidence of edema or increased epithelial permeability. The neutrophil influx was accompanied by increases in interleukin-8 in bronchoalveolar lavage fluid (p =.04). Immunohistochemistry of large Vt lungs showed increased interleukin-8 staining in bronchial epithelial cells, alveolar epithelium, alveolar macrophages, and smooth muscles of pulmonary vessels. Neutrophil depletion attenuated the interleukin-8 increase in the lung. Large Vt did not increase plasma interleukin-8 or tumor necrosis factor-alpha in plasma and bronchoalveolar lavage fluid. No expression of p-selectin or intercellular adhesion molecule-1 was observed. CONCLUSIONS: Cyclic overstretching of normal rabbit lungs with noninjurious large Vt produced neutrophil influx and interleukin-8 increase in bronchoalveolar lavage fluid. Production of pulmonary interleukin-8 by lung overstretch might require the interaction between resident lung cells and migrated neutrophils. This study suggests that large Vt ventilation potentiates the predisposed, subclinical lung injury, such as nosocomial pneumonia or aspiration of gastric contents.

Animals↗
PubMed2004

[Bacteria isolated from surgical infections and its susceptibilities to antimicrobial agents--special references to bacteria isolated between April 2002 and March 2003].

Tendency of isolated bacteria from infections in general surgery during the period from April 2002 to March 2003 were investigated in a multicenter study in Japan, and the following results were obtained. In this series, 334 strains were isolated from 131 (75.3%) of 174 patients with surgical infections. One hundred and seventy-one strains were isolated from primary infections, and 163 strains were isolated from post-operative infections. From primary infections, anaerobic Gram-positive bacteria were predominant, while aerobic Gram-positive bacteria were predominant from postoperative infections. Among aerobic Gram-positive bacteria, although the isolation rate of Staphylococcus aureus was the highest, followed by that of Enterococcus faecalis from primary infections, the isolation rate of E. faecalis was the highest from postoperative infections. Among anaerobic Gram-positive bacteria, the isolation rate of Peptostreptococcus spp. was the highest from both types of infections. Among aerobic Gram-negative bacteria, Escherichia coli was the most predominantly isolated from primary infections, followed by Klebsiella pneumoniae and Pseudomonas aeruginosa in this order, and from postoperative infections, E. coli was the most predominantly isolated, followed by P. aeruginosa, Enterobacter cloacae, and Citobacter freundii. Among anaerobic Gram-negative bacteria, the isolation rate of Bacteroides fragilis group was the highest from both types of infections. The isolation rate of aerobic Gram-negative bacteria from primary infections and that of aerobic Gram-positive bacteria from postoperative infections were high in the last several years. We noticed no vancomycin-resistant Gram-positive cocci nor P. aeruginosa producing metallo-beta-lactamase. But we noticed cefazolin-resistant E. coli probably producing extended spectrum beta-lactamase.

Anti-Bacterial Agents↗
PubMed2004

[Understanding the pathogenetic mechanisms of SIRS and sepsis and development of innovative therapies of sepsis].

The concept of systemic inflammatory response syndrome (SIRS) was introduced in 1992 to define and objectively diagnose sepsis. Over the last decade, the definition of sepsis has been used for inclusion criteria of multicenter trials to develop innovative therapies of sepsis. With the recent understanding of the pathogenetic mechanisms of sepsis, many drugs have been tested, but only two drugs (activated protein C and neutrophil-elastase inhibitor) have been approved for clinical use in sepsis or SIRS. Further understanding of basic pathophysiology of SIRS and sepsis holds promise to develop a new therapeutic strategy to improve survival of patients with SIRS and sepsis.

Humans↗
PubMed2004

[Evaluation of severity for systemic inflammatory response syndrome and sepsis].

Systemic inflammatory response syndrome (SIRS) is defined by four simple clinical and laboratory indices and now widely accepted for diagnosing sepsis. However, since the SIRS criteria include patients with a wide range of severity, other parameters are necessary to evaluate the severity and outcome of the patients. In this review, we discussed several methods to estimate the severity of SIRS, such as number of positive SIRS indices among four, duration of SIRS, plasma IL-6 and procalcitonin, etc.

Humans↗
PubMed2003

Role of vagal control in vasovagal syncope.

The vasovagal reaction is thought to be caused by sympathetic withdrawal and vagal augmentation. While measurements of muscle sympathetic nerve activity support sympathetic withdrawal in tilt induced syncope, the results of previous attempts to quantify vagal control using spectral analyses of heart rate variability (HRV) remain controversial. The sampling period used in the HRV studies is related to the discordant results. In the present study, HRV was computed every second using wavelet transformation to clarify the role of vagal control in tilt induced syncope during the 80-degree head-up tilt test (positive: 10 patients with vasovagal syncope; negative: 10 patients with vasovagal syncope, and 10 control subjects). Autonomic modulations were assessed using the absolute power of the low frequency (LF) (0.04-0.15 Hz) and high frequency (HF) (0.15-2.00 Hz) oscillatory components of R-R variability. Although the LF did not change during the tilt procedure, a decrease in the systolic arterial pressure (SAP) and increases in the R-R interval and HF were observed for the last 30 seconds before the tilt induced syncope in the tilt-positive group. Analyzing the hemodynamic measurements and spectral indices for the last 5 minutes preceding the tilt induced syncope, the study found that the SAP, R-R interval, and HF changed simultaneously during the 30-second period immediately before the tilt induced syncope. Further, the HF was positively correlated with the R-R interval and negatively correlated with the SAP. In conclusion, continuous spectral analysis of the R-R interval demonstrated increased vagal influence on the heart in tilt induced syncope.

Adult↗
PubMed2003

[Sepsis].

Explore the source record for details and available documents.

Anti-Bacterial Agents↗
PubMed2003

[Compulsory postgraduate clinical training and surgical education].

In April 2004, a new training system for physicians and surgeons will take effect in Japan. All medical graduates, after passing the National Medical Practitioners Examination, are to complete a two-year compulsory clinical training program, which includes rotations to the clinical services of internal medicine, surgery, emergency medicine, pediatrics, obstetrics and gynecology, psychiatry, and regional primary practice. Hospitals offering training programs must be approved by the Ministry of Health, Welfare and Labor. The trainees will be provided with reasonable stipends. In accordance with the introduction of new system, the current surgical training system is to be renovated and the terms for surgical trainees to be eligible for surgical specialty boards must be reviewed.

Education, Medical, Graduate↗
PubMed2003

[Bacteria isolated from surgical infections and its susceptibilities to antimicrobial agents--special references to bacteria isolated between April 2001 and March 2002].

Isolated bacteria from infections in general surgery during the period from April 2001 to March 2002 were investigated in a multicenter study in Japan, and the following results were obtained. In this series, four hundred and twenty strains were isolated from 175 (79.2%) of 221 patients with surgical infections. One hundred and eighty-six strains were isolated from primary infections, and 234 strains were isolated from postoperative infections. From primary infections, anaerobic Gram-positive bacteria were predominant, while from postoperative infections, aerobic Gram-positive bacteria were predominant. Among aerobic Gram-positive bacteria, although the isolation rate of Staphylococcus aureus was the highest, followed by that of Enterococcus faecalis from primary infections, the isolation rate of E. faecalis was the highest from postoperative infections. Among anaerobic Gram-positive bacteria, the isolation rate of Peptostreptococcus spp. was the highest from both types of infections. Among aerobic Gram-negative bacteria, Escherichia coli was the most predominantly isolated from primary infections, followed by Klebsiella pneumoniae and Pseudomonas aeruginosa in this order, and from postoperative infections, P. aeruginosa was the most predominantly isolated, followed by Enterobacter spp., E. coli and Klebsiella spp. Among anaerobic Gram-negative bacteria, the isolation rate of Bacteroides fragilis group was the highest from both types of infections. The isolation rate of aerobic Gram-negative bacteria from primary infections and that of aerobic Gram-positive bacteria from postoperative infections were high in the last several years. We noticed no vancomycin-resistant Gram-positive cocci.

Anti-Bacterial Agents↗
PubMed2002

Prior burn insult induces lethal acute lung injury in endotoxemic mice: effects of cytokine inhibition.

Many patients who experience surgical stress, including burn injury, become susceptible to severe sepsis and septic organ dysfunction, which remains the primary contributor to morbidity and mortality in burn patients. In the present study, we developed a murine model of burn-primed sublethal endotoxemia by producing a 15% BSA full-thickness burn on the dorsum of BALB/c mice under ether anesthesia and administering 10 mg/kg of LPS intravenously on day 11 to model endotoxemia. The prior burn injury in this model induced two-peaked production of cytokines, TNF-alpha, and macrophage inflammatory protein-2 at 2 and 12 h after LPS administration, and it was associated with increased mortality. We also assessed the effect of pharmacological modulation with cytokine synthesis inhibitors prednisolone and JTE-607 and found that pretreatment with them attenuated later cytokine production and decreased mortality after LPS administration. We speculate that the prior burn injury primed the mice for the secondary insult via cytokine production. These results also suggested that an anticytokine strategy might serve as a novel prophylactic therapy for septic organ dysfunction in burn-primed patients.

Acute Disease↗
PubMed2002

Use of antifungal agents in febrile patients nonresponsive to antibacterial treatment: the current status in surgical and critical care patients in Japan.

Disseminated candidiasis is difficult to diagnose and treat, and often becomes life-threatening in critically ill patients. However, guidelines or consensus views regarding the management of disseminated candidiasis do not exist in Japan. To develop feasible guidelines in Japan, we studied the current status of antifungal treatment in critically ill patients in Japan. From April 1999 to January 2000, critically ill patients from either surgical wards or critical care/intensive care units of 26 teaching hospitals were studied, using a prospective enrollment protocol. Patient enrollment criteria included persistent fever(> or =38 degrees C) for 3 days or more despite antibacterial agent administration. Data were entered at each institution and managed centrally using Clinware software. Of the 200 patients in the study, 68 (34%) received antifungal agents. Factors associated with antifungal treatment in the 68 patients included: central venous or pulmonary artery catheter, re-surgery, carbapenem or cephem administration, prolonged antibacterial agent administration, and high body temperature. Proven or probable disseminated candidiasis was presumed or diagnosed by culture in 34 patients, and by clinical signs and/or serological tests in 34 patients. Fungi isolated from blood included Candida albicans (57%), C. tropicalis (14%), C. parapsilosis (7%), C. glabrata (7%), and others (14%). Treatment patterns were as follows: 65 patients (96%) were treated with fluconazole (60 as monotherapy and 5 with amphotericin B); 2 patients, with miconazole; and 1 patient, with amphotericin B. Excluding 6 unevaluable cases, antifungal treatment was efficacious in 75% (21/28) of the patients with positive fungal culture and in 68% (23/34) of patients diagnosed by other means.

Anti-Bacterial Agents↗