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Featured researches published by Isao Nagata.


Hemodialysis International | 2013

Who may not benefit from continuous renal replacement therapy in acute kidney injury

Hiroo Kawarazaki; Shigehiko Uchino; Natsuko Tokuhira; Tetsu Ohnuma; Yoshitomo Namba; Shinshu Katayama; Noriyoshi Toki; Kenta Takeda; Hideto Yasuda; Makiko Uji; Isao Nagata

This study aimed to identify factors that may predict early kidney recovery (less than 48 hours) or early death (within 48 hours) after initiating continuous renal replacement therapy (CRRT) in acute kidney injury (AKI) patients. This is a multicenter retrospective observational study of 14 Japanese Intensive care units (ICUs) in 12 tertiary hospitals. Consecutive adult patients with severe AKI requiring CRRT admitted to the participating ICUs in 2010 (n = 343) were included. Patient characteristics, variables at CRRT initiation, settings, and outcomes were collected. Patients were grouped into early kidney recovery group (CRRT discontinuation within 48 hours after initiation, n = 52), early death group (death within 48 hours after CRRT initiation, n = 52), and the rest as the control group (n = 239). The mean duration of CRRT in the early kidney recovery group and early death group was 1.3 and 0.9 days, respectively. In multivariable regression analysis, in comparison with the control group, urine output (mL/h) (odds ratio [OR]: 1.02, 95% confidence interval [CI]: 1.01–1.03), duration between ICU admission to CRRT initiation (days) (OR: 0.65, 95% CI: 0.43–0.87), and the sepsis‐related organ failure assessment score (OR: 0.87, 95% CI; 0.78–0.96) were related to early kidney recovery. Serum lactate (mmol/L) (OR: 1.19, 95% CI: 1.11–1.28), albumin (g/dL) (OR: 0.52, 95% CI: 0.28–0.92), vasopressor use (OR: 3.68, 95% CI: 1.37–12.16), and neurological disease (OR: 9.64, 96% CI: 1.22–92.95) were related to early death. Identifying AKI patients who do not benefit from CRRT and differentiating such patients from the study cohort may allow previous and future studies to effectively evaluate the indication and role of CRRT.


Critical Care Medicine | 2013

Validity of low-intensity continuous renal replacement therapy*.

Shigehiko Uchino; Noriyoshi Toki; Kenta Takeda; Tetsu Ohnuma; Yoshitomo Namba; Shinshu Katayama; Hiroo Kawarazaki; Hideto Yasuda; Makiko Uji; Natsuko Tokuhira; Isao Nagata

Objective:To study the hospital mortality of patients with severe acute kidney injury treated with low-intensity continuous renal replacement therapy. Design:Multicenter retrospective observational study (Japanese Society for Physicians and Trainees in Intensive Care), combined with previously conducted multinational prospective observational study (Beginning and Ending Supportive Therapy). Setting:Fourteen Japanese ICUs in 12 tertiary hospitals (Japanese Society for Physicians and Trainees in Intensive Care) and 54 ICUs in 23 countries (Beginning and Ending Supportive Therapy). Patients:Consecutive adult patients with severe acute kidney injury requiring continuous renal replacement therapy admitted to the participating ICUs in 2010 (Japanese Society for Physicians and Trainees in Intensive Care, n = 343) and 2001 (Beginning and Ending Supportive Therapy Beginning and Ending Supportive Therapy, n = 1,006). Interventions:None. Measurements and Main Results:Patient characteristics, variables at continuous renal replacement therapy initiation, continuous renal replacement therapy settings, and outcomes (ICU and hospital mortality and renal replacement therapy requirement at hospital discharge) were collected. Continuous renal replacement therapy intensity was arbitrarily classified into seven subclasses: less than 10, 10–15, 15–20, 20–25, 25–30, 30–35, and more than 35 mL/kg/hr. Multivariable logistic regression analysis was conducted to investigate risk factors for hospital mortality. The continuous renal replacement therapy dose in the Japanese Society for Physicians and Trainees in Intensive Care database was less than half of the Beginning and Ending Supportive Therapy database (800 mL/hr vs 2,000 mL/hr, p < 0.001). Even after adjusting for the body weight and dilution factor, continuous renal replacement therapy intensity was statistically different (14.3 mL/kg/hr vs 20.4 mL/kg/hr, p < 0.001). Patients in the Japanese Society for Physicians and Trainees in Intensive Care database had a lower ICU mortality (46.1% vs 55.3%, p = 0.003) and hospital mortality (58.6% vs 64.2%, p = 0.070) compared with patients in the Beginning and Ending Supportive Therapy database. In multivariable regression analysis after combining the two databases, no continuous renal replacement therapy intensity subclasses were found to be statistically different from the reference intensity (20–25 mL/kg/hr). Several sensitivity analyses (patients with sepsis, patients from Western countries in the Beginning and Ending Supportive Therapy database) confirmed no intensity-outcome relationship. Conclusions:Continuous renal replacement therapy at a mean intensity of 14.3 mL/kg/hr did not have worse outcome compared with 20–25 mL/kg/hr of continuous renal replacement therapy, currently considered the standard intensity. However, our study is insufficient to support the use of low-intensity continuous renal replacement therapy, and more studies are needed to confirm our findings.


Critical Care | 2016

Resuscitative endovascular balloon occlusion of the aorta versus aortic cross clamping among patients with critical trauma: a nationwide cohort study in Japan.

Toshikazu Abe; Masatoshi Uchida; Isao Nagata; Daizoh Saitoh; Nanako Tamiya

BackgroundMeasures of aortic occlusion (AO) for resuscitation in patients with severe torso trauma remain controversial. Our aim was to characterize the current use of resuscitative endovascular balloon occlusion of the aorta (REBOA) and resuscitative open aortic cross-clamping (ACC), and to evaluate whether REBOA should be an alternative method to resuscitative open ACC.MethodsThis study was a retrospective cohort study between 2004 and 2013 from a nationwide trauma registry in Japan. Participants were selected who underwent either REBOA or ACC. Their characteristics, interventions, and outcomes were analyzed to compare REBOA and ACC directly. The primary outcome was in-hospital mortality and the secondary outcome was mortality in the emergency department. Logistic regression analysis was performed to compare the outcomes between REBOA and ACC with adjustment for severity; 1:1 propensity score matching was also performed.ResultsOf the 159,157 trauma patients, 903 were eligible based on the selection criteria. Overall, 405/607 patients (67%) who had REBOA died compared to 210/233 patients (90%) who had ACC. Patients with REBOA had higher revised trauma score (RTS) (mean ± SD, 5.2 ± 2.0 vs. 4.2 ± 2.2; P < 0.001) but higher Injury Severity Score (ISS) (median (interquartile); 34 (25) vs. 34 (20); P < 0.001), and higher probability of survival (0.43 ± 0.36 vs. 0.27 ± 0.30; P < 0.001) compared to those with ACC. REBOA had an odds ratio (OR) for in-hospital mortality of 0.309 (95% confidence interval (CI) = 0.190–0.502) adjusting for trauma and injury severity score using a logistic regression model (n = 903). Similar associations were observed adjusting for RTS (OR = 0.224; 95% CI = 0.129–0.700) or adjusting for ISS (OR, 0.188; 95% CI, 0.116 to 0.303). In the propensity score-matched cohort (n = 304), REBOA was associated with lower mortality compared to ACC (OR, 0.261; 95% CI, 0.130 to 0.523). Patients with REBOA had less severe chest complications than those with ACC (Abbreviated Injury Scale thorax, 3.8 ± 0.8 vs. 4.2 ± 0.8; P < 0.001), although physiological severity and backgrounds were similar in this population.ConclusionsPatients who underwent AO had a high mortality. REBOA might be a favorable alternative method to resuscitative ACC for severe torso trauma although some indication bias could still remain. Further studies are needed to elucidate optimal indications.


Journal of Critical Care | 2015

Sepsis may not be a risk factor for mortality in patients with acute kidney injury treated with continuous renal replacement therapy

Isao Nagata; Shigehiko Uchino; Natsuko Tokuhira; Tetsu Ohnuma; Yoshitomo Namba; Shinshu Katayama; Hiroo Kawarazaki; Noriyoshi Toki; Kenta Takeda; Hideto Yasuda; Makiko Uji

PURPOSE We aimed to study the clinical characteristics, courses, and outcomes of critically ill patients with septic acute kidney injury (AKI) treated with continuous renal replacement therapy (CRRT) in comparison with nonseptic AKI treated with CRRT. METHODS This is a multicenter retrospective observational study conducted in 14 Japanese intensive care units in 2010. All adult patients with severe AKI treated with CRRT were eligible (n = 343), and information on patient characteristics, variables at CRRT initiation, CRRT settings, and outcomes was collected. Patients were categorized into the septic AKI group and the nonseptic AKI group according to contributing factors to AKI. RESULTS Approximately half of study patients (48.7%) had sepsis/septic shock as a contributing factor to AKI, and patients with septic AKI treated with CRRT had more serious clinical conditions than patients with nonseptic AKI. However, no significant difference was observed in intensive care unit mortality (48.5% vs 43.8%; P = .44) and hospital mortality (61.1% vs 56.3%; P = .42) between patients with septic and nonseptic AKIs treated with CRRT. Furthermore, sepsis was associated with lower hospital mortality (odds ratio, 0.378; P = .012) in multivariable regression analysis. CONCLUSION Sepsis may not be a risk factor for mortality in patients with AKI whose condition has become severe enough to require CRRT.


Critical Care | 2014

The lower limit of intensity to control uremia during continuous renal replacement therapy

Hideto Yasuda; Shigehiko Uchino; Makiko Uji; Tetsu Ohnuma; Yoshitomo Namba; Shinshu Katayama; Hiroo Kawarazaki; Noriyoshi Toki; Kenta Takeda; Natsuko Tokuhira; Isao Nagata

IntroductionThe recommended lower limit of intensity during continuous renal replacement therapy (CRRT) is 20 or 25 mL/kg/h. However, limited information is available to support this threshold. We aimed to evaluate the impact of different intensities of CRRT on the clearance of creatinine and urea in critically ill patients with severe acute kidney injury (AKI).MethodsThis is a multicenter retrospective study conducted in 14 Japanese ICUs in 12 centers. All patients older than 18 years and treated with CRRT due to AKI were eligible. We evaluated the effect of CRRT intensity by two different definitions: daily intensity (the mean intensity over each 24-h period) and average intensity (the mean of daily intensity during the period while CRRT was performed). To study the effect of different CRRT intensity on clearance of urea and creatinine, all patients/daily observations were arbitrarily allocated to one of 4 groups based on the average intensity and daily intensity: <10, 10-15, 15-20, and >20 mL/kg/h.ResultsTotal 316 patients were included and divided into the four groups according to average CRRT intensity. The groups comprised 64 (20.3%), 138 (43.7%), 68 (21.5%), and 46 patients (14.6%), respectively. Decreases in creatinine and urea increased as the average intensity increased over the first 7 days of CRRT. The relative changes of serum creatinine and urea levels remained close to 1 over the 7 days in the “<10” group. Total 1,101 daily observations were included and divided into the four groups according to daily CRRT intensity. The groups comprised 254 (23.1%), 470 (42.7%), 239 (21.7%), and 138 observations (12.5%), respectively. Creatinine and urea increased (negative daily change) only in the “<10“ group and decreased with the increasing daily intensity in the other groups.ConclusionsThe lower limit of delivered intensity to control uremia during CRRT was approximately between 10 and 15 mL/kg/h in our cohort. A prescribed intensity of approximately 15 mL/kg/h might be adequate to control uremia for patients with severe AKI in the ICU. However, considering the limitations due to the retrospective nature of this study, prospective studies are required to confirm our findings.


BMJ Open | 2016

Factors related to prolonged on-scene time during ambulance transportation for critical emergency patients in a big city in Japan: a population-based observational study

Isao Nagata; Toshikazu Abe; Yoshinori Nakata; Nanako Tamiya

Objectives We aimed to investigate the factors related to prolonged on-scene times, which were defined as being over 30 min, during ambulance transportation for critical emergency patients in the context of a large Japanese city. Design A population-based observational study. Setting Kawasaki City, Japans eighth largest city. Participants The participants in this study were all critical patients (age ≥15 years) who were transported by ambulance between April 2010 and March 2013 (N=11 585). Outcome measures On-scene time during ambulance transportation for critical emergency patients. Results The median on-scene time for all patients was 17 min (IQR 13–23). There was a strong correlation between on-scene time and the number of phone calls to hospitals from emergency medical service (EMS) personnel (p<0.001). In multivariable logistic regression, the number of phone calls to hospitals from EMS personnel, intoxication, minor disease and geographical area were associated with on-scene times over 30 min. Age, gender, day of the week and time of the day were not associated with on-scene times over 30 min. Conclusions To make on-scene time shorter, it is vital to redesign our emergency system and important to develop a system that accommodates critical patients with intoxication and minor disease, and furthermore to reduce the number of phone calls to hospitals from EMS personnel.


American Journal of Nephrology | 2015

External Validation for Acute Kidney Injury Severity Scores: A Multicenter Retrospective Study in 14 Japanese ICUs.

Tetsu Ohnuma; Shigehiko Uchino; Noriyoshi Toki; Kenta Takeda; Yoshitomo Namba; Shinshu Katayama; Hiroo Kawarazaki; Hideto Yasuda; Makiko Uji; Natsuko Tokuhira; Isao Nagata

Background/Aims: Acute kidney injury (AKI) is associated with high mortality. Multiple AKI severity scores have been derived to predict patient outcome. We externally validated new AKI severity scores using the Japanese Society for Physicians and Trainees in Intensive Care (JSEPTIC) database. Methods: New AKI severity scores published in the 21st century (Mehta, Stuivenberg Hospital Acute Renal Failure (SHARF) II, Program to Improve Care in Acute Renal Disease (PICARD), Vellore and Demirjian), Liano, Simplified Acute Physiology Score (SAPS) II and lactate were compared using the JSEPTIC database that collected retrospectively 343 patients with AKI who required continuous renal replacement therapy (CRRT) in 14 intensive care units. Accuracy of the severity scores was assessed by the area under the receiver-operator characteristic curve (AUROC, discrimination) and Hosmer-Lemeshow test (H-L test, calibration). Results: The median age was 69 years and 65.8% were male. The median SAPS II score was 53 and the hospital mortality was 58.6%. The AUROC curves revealed low discrimination ability of the new AKI severity scores (Mehta 0.65, SHARF II 0.64, PICARD 0.64, Vellore 0.64, Demirjian 0.69), similar to Liano 0.67, SAPS II 0.67 and lactate 0.64. The H-L test also demonstrated that all assessed scores except for Liano had significantly low calibration ability. Conclusions: Using a multicenter database of AKI patients requiring CRRT, this study externally validated new AKI severity scores. While the Demirjians score and Lianos score showed a better performance, further research will be required to confirm these findings.


BMJ Open | 2018

Ten-year inhospital mortality trends for patients with trauma in Japan: a multicentre observational study

Isao Nagata; Toshikazu Abe; Masatoshi Uchida; Daizoh Saitoh; Nanako Tamiya

Objectives Trauma is one of the main causes of death in Japan, and treatments and prognoses of these injuries are constantly changing. We therefore aimed to investigate a 10-year trend (2004–2013) in inhospital mortality among patients with trauma in Japan. Design Multicentre observational study. Setting Japanese nationwide trauma registry (the Japan Trauma Data Bank) data. Participants All patients with trauma whose Injury Severity Score (ISS) were 3 and above, who were aged 15 years or older, and whose mechanisms of injury (MOI) were blunt and penetrating between 2004 and 2013 (n=90 833). Outcome measures A 10-year trend in inhospital mortality. Results Inhospital mortality for all patients with trauma significantly decreased over the study decade in our Cochran-Armitage test (P<0.001). Similarly, inhospital mortality for patients with ISS 16 or more and patients who scored 50% or better on the Trauma and Injury Severity Score (TRISS) probability of survival scale significantly decreased (P<0.001). In addition, the OR for inhospital mortality of these three patient groups decreased yearly after adjusting for age, gender, MOI, ISS, Glasgow Coma Scale, systolic blood pressure and respiratory rate on hospital arrival in multivariable logistic regression analyses. Furthermore, inhospital mortality for patient with blunt trauma significantly decreased in injury mechanism-stratified Mantel-extension testing (P<0.001). Finally, multivariable logistic regression analyses showed that the OR for inhospital mortality of patients with ISS 16 and over decreased each year after adding and adjusting for means of transportation and usage of whole-body CT. Conclusion Inhospital mortality for patients with trauma in Japan significantly decreased during the study decade after adjusting for patient characteristics, injury severity and the response environment after injury.


Critical Care Medicine | 2015

166: OUT-OF-HOSPITAL CARDIAC ARREST (OHCA) IN CENTENARIANS IN JAPAN

Toshikazu Abe; Nanako Tamiya; Isao Nagata; Uchida Masatoshi; Yui Yamaoka

Crit Care Med 2015 • Volume 43 • Number 12 (Suppl.) cost between regular unit and ICU of


Anaesthesia and Intensive Care | 2016

Factors predicting successful discontinuation of continuous renal replacement therapy.

Shinshu Katayama; Shigehiko Uchino; Makiko Uji; Tetsu Ohnuma; Yoshitomo Namba; Hiroo Kawarazaki; Noriyoshi Toki; Kenta Takeda; Hideto Yasuda; Natsuko Tokuhira; Isao Nagata

3200, and assuming a 1-day ICU stay after unwarranted transfer, the decrease in ICU transfers equates to a monthly saving of

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Hiroo Kawarazaki

St. Marianna University School of Medicine

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Kenta Takeda

Hyogo College of Medicine

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Natsuko Tokuhira

Kyoto Prefectural University of Medicine

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Shigehiko Uchino

Jikei University School of Medicine

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Tetsu Ohnuma

Jichi Medical University

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