ATAkira Takasu

Akira Takasu

*This is an algorithmically generated author record based on publicly available information.

Current Organizations / Institutes

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Previous Organizations / Institutes

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Akira Takasu has a total of 236 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    Epidemiology of Bicycle Crashes in Japanese Core Regional City: Characteristics of Single- and Multiple-Rider Bicycle Crashes

    by Koshi Ota, Hiroshi Tsuda, Kanna Ota, Akira Takasu

    Background/Objectives: Comprehensive epidemiological studies of bicycle crashes involving all ages in Japan are limited, particularly regarding multiple-rider incidents. This study investigated the epidemiology of single- and multiple-rider bicycle crashes in a Japanese core regional city. Methods: Ambulance transport data from Takatsuki City (1 January 2014 to 31 July 2024) were retrospectively analyzed, including demographics, crash characteristics, and severity of injury for bicycle crash patients. The primary outcome was examination of the epidemiology of bicycle crashes with moderate and severe severity or severe and fatal severity, encompassing both single- and multiple-rider incidents. Statistical tests and logistic regression analysis were used. Results: For 6683 transported patients, 6377 (95.4%) involved single-rider crashes and 306 (4.6%) involved multiple riders. Single-rider crash patients were older and more often male. Moderate or greater injuries occurred in 625 single-rider and 11 multiple-rider crash patients. No severe or fatal injuries occurred in multiple-rider crashes. General roadways and intersections were common crash locations. Male sex and older age predicted greater injury severity in single-rider crashes. Fifty single-rider bicycle crashes resulted in severe or greater severity injuries, and four fatal crashes were recorded. Conclusions: This study uniquely details multiple-rider bicycle crashes in Japan, revealing a lower severity of injuries compared to single-rider crashes.

  • Open Access

    Serum sodium trajectories impact clinical outcomes in extracorporeal resuscitation of cardiac arrest: A multicenter retrospective cohort study

    by Yu Amemiya, Ryo Hisamune, Kazuma Yamakawa, Ryosuke Zushi, Hitoshi Kobata, Akihiko Inoue, Toru Hifumi, Tetsuya Sakamoto, Yasuhiro Kuroda, Akira Takasu, et al.

  • Top Cited Papers
    Open Access

    Two-year trajectory of functional recovery and quality of life in post-intensive care syndrome: a multicenter prospective observational study on mechanically ventilated patients with coronavirus disease-19

    by Junji Hatakeyama, Kensuke Nakamura, Shigeaki Inoue, Keibun Liu, Kazuma Yamakawa, Takeshi Nishida, Shinichiro Ohshimo, Satoru Hashimoto, Naoki Kanda, Shotaro Aso, et al.

    Background: Post-intensive care syndrome (PICS) affects the quality of life (QOL) of survivors of critical illness. Although PICS persists for a long time, the longitudinal changes in each component and their interrelationships over time both remain unclear. This multicenter prospective study investigated the 2-year trajectory of PICS and its components as well as factors contributing to deterioration or recovery in mechanically ventilated patients with coronavirus disease 2019 (COVID-19), and also attempted to identify possible countermeasures. Methods: Patients who survived COVID-19 requiring mechanical ventilation completed questionnaires on the Barthel index, Short-Memory Questionnaire, Hospital Anxiety and Depression Scale, and EuroQol 5 dimensions 5-level every six months over a two-year period. Scores were weighted to account for dropouts, and the trajectory of each functional impairment was evaluated with alluvial diagrams. The prevalence of PICS and factors impairing or restoring function were examined using generalized estimating equations considering trajectories. Results: Among 334 patients, PICS prevalence rates in the four completed questionnaires were 72.1, 78.5, 77.6, and 82.0%, with cognitive impairment being the most common and lower QOL being noted when multiple impairments coexisted. Physical function and QOL indicated that many patients exhibited consistent trends of either recovery or deterioration. In contrast, cognitive function and mental health revealed considerable variability, with many patients showing fluctuating ratings in the later surveys. Delirium was associated with worse physical and mental health and poor QOL, while prolonged ventilation was associated with poor QOL. Living with family was associated with the recovery of all functions and QOL, while extracorporeal membrane oxygenation (ECMO) was associated with the recovery of cognitive function and mental health. Conclusions: Critically ill patients had PICS for a long period and followed different trajectories for each impairment component. Based on trajectories, known PICS risk factors such as prolonged ventilation and delirium were associated with impaired recovery, while ECMO and the presence of family were associated with recovery from PICS. In critically ill COVID-19 patients, delirium management and family interventions may play an important role in promoting recovery from PICS. Trial registration number: UMIN000041276, August 01, 2020.


  • Open Access

    Association Between IV Contrast Media Exposure and Acute Kidney Injury in Patients Requiring Emergency Admission: A Nationwide Observational Study in Japan

    by Ryo Hisamune, Kazuma Yamakawa, Yutaka Umemura, Noritaka Ushio, Katsunori Mochizuki, Ryota Inokuchi, Kent Doi, Akira Takasu

    OBJECTIVE: This study aimed to elucidate the association between IV contrast media CT and acute kidney injury (AKI) and in-hospital mortality among patients requiring emergency admission. DESIGN: In this retrospective observational study, we examined AKI within 48 hours after CT, renal replacement therapy (RRT) dependence at discharge, and in-hospital mortality in patients undergoing contrast-enhanced CT or nonenhanced CT. We performed 1:1 propensity score matching to adjust for confounders in the association between IV contrast media use and outcomes. Subgroup analyses were performed according to age, sex, diagnosis at admission, ICU admission, and preexisting chronic kidney disease (CKD). SETTING AND PATIENTS: This study used the Medical Data Vision database between 2008 and 2019. This database is Japan’s largest commercially available hospital-based claims database, covering about 45% of acute-care hospitals in Japan, and it also records laboratory results. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The study included 144,149 patients with (49,057) and without (95,092) contrast media exposure, from which 43,367 propensity score-matched pairs were generated. Between the propensity score-matched groups of overall patients, exposure to contrast media showed no significant risk of AKI (4.6% vs. 5.1%; odds ratio [OR], 0.899; 95% CI, 0.845–0.958) or significant risk of RRT dependence (0.6% vs. 0.4%; OR, 1.297; 95% CI, 1.070–1.574) and significant benefit for in-hospital mortality (5.4% vs. 6.5%; OR, 0.821; 95% CI, 0.775–0.869). In subgroup analyses regarding preexisting CKD, exposure to contrast media was a significant risk for AKI in patients with CKD but not in those without CKD. CONCLUSIONS: In this large-scale observational study, IV contrast media was not associated with an increased risk of AKI but concurrently showed beneficial effects on in-hospital mortality among patients requiring emergency admission.


  • Open Access

    Efficacy of unfractionated heparin in patients with moderate sepsis-induced coagulopathy: An observational study

    by Noritaka Ushio, Kazuma Yamakawa, Katsunori Mochizuki, Ryo Hisamune, Yutaka Umemura, Akira Takasu


  • Open Access

    Morel–Lavallée Lesion Treated with Single-Use Portable Negative Pressure Wound Therapy: A Case Report and Literature Review

    by Koshi Ota, Kazuaki Shimazu, Kanna Ota, Akira Takasu

    Background: A Morel–Lavallée lesion (MLL) is a traumatic, internal closed degloving injury that results from shearing of subcutaneous tissue away from underlying fascia, usually associated with high-velocity trauma. Case presentation: A 52-year-old man was transported to hospital for further follow-up of a superficial femoral artery injury. Examination on admission showed bruising seen around the left thigh. Contrast-enhanced computed tomography of the left thigh revealed hematoma with extravasation from a branch of the left superficial femoral artery, but no apparent aneurysms or femoral fractures. The patient was treated with compression bandages and discharged on hospital day 6. He left hospital able to walk unaided. He subsequently complained of left thigh pain with swelling and visited the hospital several times. He was treated at another outpatient clinic and was diagnosed with MLL. Single-use disposable portable negative pressure wound therapy (NPWT) was applied for about 2 months, achieving a stable wound site. Conclusion: We encountered a case of MLL successfully treated with single-use portable NPWT. This report presents the case of a patient with isolated MLL without fracture in the left thigh, in which the diagnosis was missed on initial admission. Finally, the patient received minor interventions including drainage along with tissue debridement and portable NPWT. We reviewed the relevant literature and summarize the pathogenesis, clinical manifestations, and treatment strategies for MLL. Emergency physicians require an increased understanding of MLL to avoid misdiagnosis and missed diagnosis.

  • Open Access

    Self-inflicted very-low-velocity penetrating head injury: A CARE-compliant case report

    by Koshi Ota, Hitoshi Kobata, Shunsuke Tomonishi, Kanna Ota, Akira Takasu

    Rationale: Low-velocity penetrating head injury (PHI) is rare, comprising 0.2% to 0.4% of head traumas, but can be devastating and is associated with significant morbidity and mortality. No previous case of very-low-velocity PHI due to self-inflicted stabbing with a gimlet has been reported. Patient concerns: A 62-year-old man was admitted to the hospital with bleeding head and abdominal wounds after stabbing his abdomen with a gimlet, and then hammering the same gimlet into his forehead and removing the gimlet himself. Diagnoses: Upon examination at admission, stab wounds were present on the forehead and the right upper quadrant. Computed tomography (CT) of the head revealed a bone defect in the left frontal bone and showed the intracranial path of the gimlet surrounded by mild hemorrhage and pneumocephalus. Magnetic resonance imaging (MRI) confirmed a small amount of hemorrhage with pneumocephalus but no vascular injury. Interventions: Conservative treatment without surgery. Outcomes: Follow-up MRI on hospital day 58 showed no abscess or traumatic intracranial aneurysm. The patient achieved full recovery of motor and mental functions with conservative treatment and was discharged on hospital day 69. Lessons: Very-low-velocity PHI might be successfully treated with conservative treatment.


  • Open Access

    Vitamin B1 Deficiency Identified from Incidental Detection of Hyperlactatemia: A Case Report

    by Yuki Omura, Koshi Ota, Akira Takasu, Tomio Suzuki

    Introduction: Vitamin B1 deficiency poses a significant risk of impaired consciousness, with manifestations ranging from anorexia and fatigue to severe neurological and cardiovascular disturbances. Wernicke’s encephalopathy, a neurological disorder stemming from vitamin B1 deficiency, presents as the triad of ophthalmoplegia, altered mental state, and cerebellar ataxia. However, these symptoms are not consistently present, complicating the diagnosis. In addition, subclinical vitamin B1 deficiency can progress unnoticed until severe complications arise. Studies indicate a high rate of undiagnosed cases, emphasizing the need for early detection and intervention. Case presentation: We present the case of a 65-year-old man in whom hyperlactatemia was incidentally detected, leading to the diagnosis of vitamin B1 deficiency. The patient, presenting with vertigo and vomiting, had been eating boxed lunches bought from convenience stores following the death of his wife 3 years earlier. Vertigo gradually improved with rest, but the persistence of hyperlactatemia prompted further investigation, revealing low vitamin B1 levels and high pyruvate levels. Treatment with dietary adjustments and supplements significantly improved his symptoms. Discussion: In this case, hyperlactatemia was found in a vertigo patient, revealing asymptomatic vitamin B1 deficiency. Elevated lactate is often linked with conditions like sepsis but can also stem from overlooked factors such as low vitamin B1 levels due to poor diet habits like consuming fried foods. Conclusion: This case highlights the importance of considering vitamin B1 deficiency in patients with unexplained hyperlactatemia, even in high-income countries. Early detection can prevent progression to the severe complications associated with Wernicke’s encephalopathy. Proactive measurement of lactate levels in at-risk populations may facilitate early diagnosis and intervention, ultimately improving patient outcomes.


  • Open Access

    Influence of the COVID-19 Outbreak in Vulnerable Patients (Pediatric Patients, Pregnant Women, and Elderly Patients) on an Emergency Medical Service System: A Pre- and Post-COVID-19 Pandemic Comparative Study Using the Population-Based ORION Registry

    by Koshi Ota, Masahiko Nitta, Tomonobu Komeya, Tetsuya Matsuoka, Akira Takasu

    Background and Objective: Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread all over the world. To assess the influence of the COVID-19 pandemic on emergency medical services (EMS) for vulnerable patients transported by ambulance. Materials and Methods: This study was a retrospective, descriptive study with a study period from 1 January 2019 to 31 December 2021 using the Osaka Emergency Information Research Intelligent Operation Network (ORION) system. We included all pediatric patients, pregnant women, and elderly patients ≥ 65 years of age transported by ambulance in Osaka Prefecture. The main outcome of this study was difficult-to-transport cases. We calculated the rate of difficult-to-transport cases under several conditions. Results: For the two year-long periods of 1 January 2019 to 31 December 2019 and 1 January 2021 to 31 December 2021, a total of 887,647 patients were transported to hospital by ambulance in Osaka Prefecture. The total number of vulnerable patients was 579,815 (304,882 in 2019 and 274,933 in 2021). Multivariate logistic regression analysis showed that difficult-to-transport cases were significantly more frequent in 2021 than in 2019. Difficult-to-transport cases were significantly less frequent in the vulnerable population than in the non-vulnerable population (adjusted odds ratio 0.81, 95% confidence interval 0.80–0.83; p < 0.001). Conclusion: During the pandemic (2021), difficult-to-transport cases were more frequent compared to before the pandemic (2019); however, vulnerable patients were not the cause of difficulties in obtaining hospital acceptance for transport.


  • Open Access

    Anisocoria without extraocular muscle impairment due to moderate traumatic brain injury with midbrain contusion: a case report

    by Koshi Ota, Hitoshi Kobata, Yoshisuke Hamada, Saki Mizutani, Terunari Okuyama, Kanna Ota, Yuriko Takeda, Akira Takasu

    Background: New-onset anisocoria is an important clinical clue to life-threatening intracranial injury. Anisocoria alone without impairment of extraocular muscles is a rare presentation of moderate traumatic brain injury (TBI). Case presentation: A 79-year-old woman was transported to hospital soon after falling off a bicycle. Glasgow Coma Scale score on arrival was 11 (E3V3M5). On examination at admission, she was found to be drowsy. Bruising was seen around the right eye and pupil diameters differed (right, 4.5 mm; left, 3.0 mm; both reactive to light). Computed tomography of the head revealed hemorrhagic contusion in the left temporal lobe and left pretectal area of the midbrain, right clavicular fracture, and pulmonary contusion with fractures of the 3rd and 4th ribs. Magnetic resonance imaging confirmed hemorrhagic contusion of the midbrain. The patient achieved full recovery of motor and mental functions with conservative treatment and was discharged on hospital day 17. Conclusion: We encountered a case of anisocoria without major extraocular muscle impairment due to moderate TBI with midbrain contusion.