Publications by authors named "Munetaka Hayashi"

9 Publications

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A novel mouse model of heatstroke accounting for ambient temperature and relative humidity.

J Intensive Care 2021 Apr 16;9(1):35. Epub 2021 Apr 16.

Department of Emergency, Critical Care and Disaster Medicine, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, 142-8555, Japan.

Background: Heatstroke is associated with exposure to high ambient temperature (AT) and relative humidity (RH), and an increased risk of organ damage or death. Previously proposed animal models of heatstroke disregard the impact of RH. Therefore, we aimed to establish and validate an animal model of heatstroke considering RH. To validate our model, we also examined the effect of hydration and investigated gene expression of cotransporter proteins in the intestinal membranes after heat exposure.

Methods: Mildly dehydrated adult male C57/BL6J mice were subjected to three AT conditions (37 °C, 41 °C, or 43 °C) at RH > 99% and monitored with WetBulb globe temperature (WBGT) for 1 h. The survival rate, body weight, core body temperature, blood parameters, and histologically confirmed tissue damage were evaluated to establish a mouse heatstroke model. Then, the mice received no treatment, water, or oral rehydration solution (ORS) before and after heat exposure; subsequent organ damage was compared using our model. Thereafter, we investigated cotransporter protein gene expressions in the intestinal membranes of mice that received no treatment, water, or ORS.

Results: The survival rates of mice exposed to ATs of 37 °C, 41 °C, and 43 °C were 100%, 83.3%, and 0%, respectively. From this result, we excluded AT43. Mice in the AT 41 °C group appeared to be more dehydrated than those in the AT 37 °C group. WBGT in the AT 41 °C group was > 44 °C; core body temperature in this group reached 41.3 ± 0.08 °C during heat exposure and decreased to 34.0 ± 0.18 °C, returning to baseline after 8 h which showed a biphasic thermal dysregulation response. The AT 41 °C group presented with greater hepatic, renal, and musculoskeletal damage than did the other groups. The impact of ORS on recovery was greater than that of water or no treatment. The administration of ORS with heat exposure increased cotransporter gene expression in the intestines and reduced heatstroke-related damage.

Conclusions: We developed a novel mouse heatstroke model that considered AT and RH. We found that ORS administration improved inadequate circulation and reduced tissue injury by increasing cotransporter gene expression in the intestines.
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http://dx.doi.org/10.1186/s40560-021-00546-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8052643PMC
April 2021

Hypovolemic shock induced by a large chest wall hematoma caused by a single rib fracture in an elderly patient.

Trauma Case Rep 2021 Apr 17;32:100459. Epub 2021 Mar 17.

Department of Emergency and Disaster Medicine, Showa University.

Displaced rib fractures can injure intercostal vessels leading to chest wall hematomas. As the bleeding occurs within the vessel, compression of the vessel wall helps in preventing further bleeding. Therefore, chest wall hematomas rarely result in shock. A thin 78-year-old man transferred to the emergency department with complaints of left dorsal pain due to an injury. He had a history of hypertension and aorta dissection. He arrived at the ED in a state of shock and presented with a large left dorsal wall mass. Subsequent imaging using computed tomography angiography revealed a large hyperdense hematoma at the left dorsal-flank wall along with rib fracture (11th intercostal artery). Moreover, a large fusiform aneurysm was detected from the abdominal aorta to the iliac arteries. Extravasation of the contrast agent was detected at the branch of the 11th intercostal artery, and hence, embolization was performed. The dermis, which comprises collagen and elastin fibers, plays an important role in vessel compression to prevent bleeding. The aortic media also comprises collagen and elastin fibers. Cell turnover, loss of collagen, and excessive elastolysis are associated with the formation of abdominal aortic aneurysms. The systemic degeneration of connecting tissue (collagen and elastin fiber) appears to be progress in patients with an aortic aneurysms and history of aortic dissection compared with other healthy older individuals. Physicians should be cognizant of the potential unexpected large hematoma complications if a risk of systemic connecting tissue degradation exists, as seen in patients with aortic aneurysm or aortic dissection.
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http://dx.doi.org/10.1016/j.tcr.2021.100459DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8010857PMC
April 2021

Analysis of the Relationships between Multiple Endocrine Hormones and Return of Spontaneous Circulation (ROSC) in Cardiac Arrest Patients: Possible Association of the Serum Free T4 Level with ROSC.

Int J Endocrinol 2020 30;2020:4168420. Epub 2020 Nov 30.

Division of Diabetes, Metabolism and Endocrinology, Showa University Fujigaoka Hospital, 1-30 Fujigaoka, Aoba-ku, Yokohama, Kanagawa 227-8501, Japan.

Background: Endocrine hormones are closely associated with homeostasis, so it is important to clarify hormone secretion dynamics in shock. Few reports, however, have examined the dynamics of endogenous hormone secretion relative to prognosis in cardiac arrest patients. Therefore, to clarify the roles of endocrine hormones in out-of-hospital cardiac arrest (OHCA) patients, the concentrations of anterior pituitary, thyroid, and adrenocortical hormones were measured, and their associations with return of spontaneous circulation (ROSC) were examined.

Methods: The subjects were OHCA patients transported to our Emergency Department. In addition to conventional clinical laboratory tests, the following were measured: serum TSH, serum free T3, serum free T4 (F-T4), plasma ACTH, serum cortisol, serum GH, serum IGF-1, plasma aldosterone concentration (PAC), and plasma renin activity. The primary endpoint was the presence or absence of ROSC, and the secondary endpoint was 24-hour survival.

Results: A total of 29 patients, 17 in the ROSC group and 12 in the non-ROSC group, were studied. There were associations between ROSC and low serum potassium, high F-T4, low cortisol, and low PAC on bivariate analyses. There were associations between ROSC and serum potassium, F-T4, and GH using the step-wise method. On multiple logistic regression analysis, a relationship between ROSC and high serum F-T4 level was identified by both methods. There were also associations between 24-hour survival and both low serum potassium and elevated blood glucose levels.

Conclusions: The present findings suggest a possible relationship between the serum F-T4 level and ROSC in OHCA patients. A higher serum F-T4 level might cause an increase in the -adrenergic response in cardiomyocytes and increased responsiveness to catecholamines and was possibly associated with ROSC.
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http://dx.doi.org/10.1155/2020/4168420DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7721486PMC
November 2020

Diagnosis of neurofibromatosis type 1 after rupture of aneurysm and consequent fatal hemothorax.

Am J Emerg Med 2020 07 7;38(7):1543.e3-1543.e5. Epub 2020 Apr 7.

Department of Emergency and Disaster Medicine, Showa University, Fujigaoka Hospital, 1-30 Fujigaoka Aoba-ku, Yokohama 227-8501, Japan; Department of Emergency and Disaster Medicine, Showa University, 1-5-8 Hatanodai Shinagawa-ku, Tokyo 142-8666, Japan.

Patients with neurofibromatosis type 1 (NF1) can develop both benign and malignant tumors throughout their lives. A 49-year-old man was transferred to the emergency department with complaints of sudden right dorsal pain and respiratory discomfort. He was in shock on arrival. On finding significantly decreased permeability of the left lung field in chest X-ray, drainage was immediately performed. Subsequent computed tomography (CT; Lammert et al., 2005) angiography revealed the extravasation of contrast media from the deep carotid artery, a branch of subclavian artery. It suggested rupture of an aneurysm located at a rare site; the ruptured aneurysm penetrated the pleura, causing shock. The patient was resuscitated. Transcatheter arterial embolization (TAE; Evans et al., 2010) was successfully performed. Immediate drainage, resuscitation, and TAE 2 improved his condition. Most NF1 patients have café-au-lait macules; café-au-lait macules tend to fade with age. Importantly, café-au-lait macules, neurofibromas, and Lisch nodules were noticed at admission. NF1 patients are likely to have a malignant neoplasm when they are young. The patient had been diagnosed with thyroid cancer when he was young. As his deceased mother was an NF1 patient, we diagnosed him with NF1. Detailed patient history and early-stage examination led to the early diagnosis. NF1 should be considered as an early differential diagnosis to improve the outcome of patients in such cases.
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http://dx.doi.org/10.1016/j.ajem.2020.04.004DOI Listing
July 2020

Continuous Hemodiafiltration for Pheochromocytoma Crisis with a Positive Outcome.

Intern Med 2019 Nov 10;58(21):3113-3119. Epub 2019 Jul 10.

Division of Diabetes, Metabolism and Endocrinology, Showa University Fujigaoka Hospital, Japan.

A 38-year-old woman who consulted a local doctor with chief complaints of sudden palpitations, headaches, and chest pain is herein presented. After admission, pheochromocytoma crisis was suspected. Since the patient had a history of acute heart failure and had once survived an episode of cardiac arrest, a rapid decrease in the catecholamine levels was needed. After resuscitation, pharmacological therapy with agents such as phentolamine and landiolol was administered, and continuous hemodiafiltration (CHDF) was performed to reduce the catecholamine levels. Elective surgery was then performed, and a positive outcome was achieved. This case suggests that the preoperative use of CHDF to control pheochromocytoma crisis may therefore be effective.
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http://dx.doi.org/10.2169/internalmedicine.2991-19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6875466PMC
November 2019

Investigation and treatment of pulmonary embolism as a potential etiology may be important to improve post-resuscitation prognosis in non-shockable out-of-hospital cardiopulmonary arrest: report on an analysis of the SOS-KANTO 2012 study.

Acute Med Surg 2016 07 11;3(3):250-259. Epub 2016 Mar 11.

St. Luke's International Hospital.

Background: The prognosis of non-shockable out-of-hospital cardiac arrest is worse than that of shockable out-of-hospital cardiac arrest. We investigated the associations between the etiology and prognosis of non-shockable out-of-hospital cardiac arrest patients who experienced the return of spontaneous circulation after arriving at hospital.

Methods And Results: All subjects were extracted from the SOS-KANTO 2012 study population. The subjects were 3,031 adults: (i) who had suffered out-of-hospital cardiac arrest, (ii) for whom there were no pre-hospital data on ventricular fibrillation/pulseless ventricular tachycardia until arrival at hospital, (iii) who experienced the return of spontaneous circulation after arriving at hospital. We compared the patients' prognosis after 1 and 3 months between various etiological and presumed cardiac factors. The proportion of the favorable brain function patients that developed pulmonary embolism or incidental hypothermia was significantly higher than that of the patients with presumed cardiac factors (1 month,  < 0.0001 and  < 0.0001, respectively; 3 months,  = 0.0018 and  < 0.0001, respectively). In multiple logistic regression analysis, pulmonary embolism and incidental hypothermia were found to be significant independent prognostic factors for 1- and 3-month survival and the favorable brain function rate.

Conclusions: In patients who suffer non-shockable out-of-hospital cardiac arrest, but who experience the return of spontaneous circulation after arriving at hospital, the investigation and treatment of pulmonary embolism as a potential etiology may be important for improving post-resuscitation prognosis.
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http://dx.doi.org/10.1002/ams2.183DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5667239PMC
July 2016

Systemic emphysema accompanying marked undernutrition.

Acute Med Surg 2016 04 22;3(2):143-146. Epub 2015 Jul 22.

Department of Critical Care and Emergency Medicine Showa University Fujigaoka Hospital Yokohama Kanagawa Japan.

Case: A 38-year-old mentally retarded woman was transported to the emergency room for marked undernutrition. Two months prior, she had developed tooth decay and her food intake decreased severely. Over 2 months, her weight decreased from 47 to 31 kg (-16 kg). Computed tomography (CT) revealed extensive subcutaneous, mediastinal, and retroperitoneal emphysema. She was hospitalized and treatment with central venous hyperalimentation and antibiotics was initiated. CT performed 3 weeks after hospitalization showed that the systemic emphysema had completely disappeared.

Outcome: She progressed favorably and was transferred to a specialized psychiatric hospital for further treatment.

Conclusion: Regardless of the cause, this rare complication must be taken into account when treating patients suffering from long-term starvation or undernutrition. Whole-body management including nutritional management and careful follow-up observations are appropriate for treating this condition.
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http://dx.doi.org/10.1002/ams2.146DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5667396PMC
April 2016

Liver abscessation and multiple septic pulmonary emboli associated with Lemierre's syndrome: a case report.

BMC Res Notes 2015 Mar 3;8:65. Epub 2015 Mar 3.

Division of Gastroenterology, Department of Internal Medicine, Showa University Fujigaoka Hospital, Yokohama, Kanagawa, Japan.

Background: In Lemierre's syndrome, patients first exhibit pharyngitis and peritonsillar abscessation, followed by the development of anaerobic bacterial (usually Fusobacterium necrophorum) septicemia and metastatic infections throughout the body. However, these infections rarely affect the liver. We describe a case of Lemierre's syndrome, in which the first disease manifestation was liver abscess, for drawing attention of emergency physicians to this rare but fatal disease.

Case Presentation: A 28-year-old Asian ethnicity Filipino male, who was previously healthy, entered the emergency department presenting with fever and pharyngeal pain that had persisted for 5 days. Contrast-enhanced abdominal computed tomography revealed a 3-cm area of low density in segment 6 of the liver, consistent with an abscess. Chest computed tomography also revealed that multiple nodes in both lungs were enlarged, and septic emboli were suspected. The patient was hospitalized and antibiotic treatment was initiated. On hospital day 6, blood culture results confirmed Fusobacterium necrophorum septicemia. The patient was diagnosed with Lemierre's syndrome, as pharyngitis developed into bacteremia associated with hepatic and pulmonary lesions. The patient's condition improved with antibiotics and he was discharged following three weeks of treatment in the hospital.

Conclusion: With the widespread use of antibiotics, Lemierre's syndrome is rarely encountered anymore, but it can be fatal if not properly diagnosed. It is a crucial differential diagnosis in young patients exhibiting septicemia or multiple metastatic infection of unknown origin.
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http://dx.doi.org/10.1186/s13104-015-1028-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4351970PMC
March 2015

Status of systemic oxidative stress during therapeutic hypothermia in patients with post-cardiac arrest syndrome.

Oxid Med Cell Longev 2013 26;2013:562429. Epub 2013 Aug 26.

Department of Emergency and Critical Care Medicine, Showa University Fujigaoka Hospital, Aoba-ku, Yokohama, Kanagawa 227-8501, Japan.

Therapeutic hypothermia (TH) is thought to be due to the downregulation of free radical production, although the details of this process remain unclear. Here, we investigate changes in oxidative stress and endogenous biological antioxidant potential during TH in patients with post-cardiac arrest syndrome (PCAS). Nineteen PCAS patients were enrolled in the study. Brain temperature was decreased to the target temperature of 33°C, and it was maintained for 24 h. Patients were rewarmed slowly (0.1°C/h, <1°C/day). The generation of reactive oxygen metabolites (ROMs) was evaluated in plasma samples by d-ROM test. Plasma antioxidant capacity was measured by the biological antioxidant potential (BAP) test. Levels of d-ROMs and BAP levels during the hypothermic stage (33°C) were suppressed significantly compared with pre-TH induction levels (P < 0.05), while both d-ROM and BAP levels increased with rewarming (33-36°C) and were correlated with brain temperature. Clinical monitoring of oxidative stress and antioxidant potential is useful for evaluating the redox state of patients undergoing TH after PCAS. Additional therapy to support the antioxidant potential in the rewarming stage following TH may reduce some of the observed side effects associated with the use of TH.
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http://dx.doi.org/10.1155/2013/562429DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3770059PMC
February 2014