Effectiveness of Body Armor Against Shock Waves: Preventing Blast Injury in a Confined Space.

Introduction Blast injuries in modern society often occur owing to terrorist attacks in confined spaces, particularly in urban settings, indoors, and in vehicles, leading to significant damage. Therefore, it is important to focus on blast injuries in confined spaces rather than in conventional open-field experiments. Materials and methods We used an air-driven shock wave generator (blast tube) established indoors in 2017 and conducted basic research to potentially save the lives of patients with blast injuries. Under general anesthesia, pigs were divided into with body armor (BA) and without BA groups. The pigs were fixed in the measurement chamber with their dorsal chest directly exposed to the shock wave. The driving pressure was set at 3.0 MPa to achieve a mortality rate of approximately 50%. A generated shock wave was directly applied to the pigs. Comparisons were made between the groups with respect to cardiac arrest and survival, as well as apnea, bradycardia, and hypotension, which are the triad of blast lung. Autopsies were performed to confirm the extent of the organ damage. Statistical analysis was performed using Fisher's exact test, and statistical significance was set at p<0.05. The animal experimentation was conducted according to the protocol reviewed and approved by the Animal Ethics Committee of the National Defense Medical College Hospital (approval number 19041). Results Eight pigs were assigned to the BA group and seven pigs to the non-BA group. In the non-BA group, apnea was observed in four of seven cases, three of which resulted in death. None of the eight pigs in the BA group had respiratory arrest; notably, all survived. Hypotension was observed in some pigs in each group; however, there were no cases of bradycardia in either group. Statistical analysis showed that wearing BA significantly reduced the occurrence of respiratory and cardiac arrest (p=0.026) but not survival (p=0.077). No significant differences were found in other vital signs. Conclusions Wearing BA with adequate neck and chest protection reduced mortality and it was effective to reduce cardiac and respiratory arrest against shock wave exposure. Mortality from shock wave injury appears to be associated with respiratory arrest, and the avoidance of respiratory arrest may lead to survival.

Noninvasive Ambulatory Electrocardiographic Markers from Patients with COVID-19 Pneumonia: A Report of Three Cases.

Coronavirus disease 2019 (COVID-19) has affected medical practice. More than 7,000,000 patients died worldwide after being infected with COVID-19; however, no specific laboratory markers have yet been established to predict death related to this disease. In contrast, electrocardiographic changes due to COVID-19 include QT prolongation and ST-T changes; however, there have not been studies on the ambulatory electrocardiographic markers of COVID-19. We encountered three patients diagnosed as having COVID-19 who did not have a prior history of significant structural heart diseases. All patients had abnormalities in ambulatory echocardiogram parameters detected by high-resolution 24 h electrocardiogram monitoring: positive late potentials (LPs) and T-wave alternans (TWA), abnormal heart rate variability (HRV), and heart rate turbulence (HRT). Case 1 involved a 78-year-old woman with a history of chronic kidney disease, Case 2 involved a 76-year-old man with hypertension and diabetes, and Case 3 involved a 67-year-old man with renal cancer, lung cancer, and diabetes. None of them had a prior history of significant structural heart disease. Although no significant consistent increases in clinical markers were observed, all three patients died, mainly because of respiratory failure with mild heart failure. The LP, TWA, HRV, and HRT were positive in all three cases with no significant structural cardiac disease at the initial phase of admission. The further accumulation of data regarding ambulatory electrocardiographic markers in patients with COVID-19 is needed. Depending on the accumulation of data, the LP, TWA, HRV, and HRT could be identified as potential risk factors for COVID-19 pneumonia in the early phase of admission.

Case report: Severe respiratory failure caused by licorice.

Licorice, one of the most commonly used herbs, can cause hypokalemia, metabolic alkalosis, and apparent mineralocorticoid excess, also known as pseudoaldosteronism. Herein, we present a case of diaphragmatic dysfunction caused by licorice administration. An 80-year-old woman who had been taking dietary supplements and following a restricted diet for approximately 6 months was brought to the emergency department with impaired consciousness. Chronic respiratory acidosis was observed, and hypertension and hypokalemia became more prominent during hospitalization. History revealed that she was taking herbal medicines containing licorice. Based on the results of hormone tests, the patient was diagnosed with pseudoaldosteronism. Chest radiography and pulmonary function tests confirmed the clinical diagnosis of diaphragmatic dysfunction. The metabolic alkalosis resulting from licorice administration may have contributed to the impairment of the respiratory muscles. This case suggests that caution should be exercised when using licorice in patients with preexisting health or medical issues such as advanced age, malnutrition, and electrolyte imbalance.

Invasive candidiasis presenting bronchiectatic cavity as chest radiological findings: A case report.

Invasive candidiasis is rare but is associated with high mortality in immunocompromised or critically ill patients. Here, we present a case of a 55-year-old man with untreated diabetes who was diagnosed with coronavirus disease 2019 and subsequently developed invasive candidiasis. The patient presented with fever, tachycardia, and tachypnea. Chest computed tomography revealed multiple consolidations mainly distributed around the bronchovascular bundles with bronchiectatic cavity formation, which initially raised suspicion for invasive pulmonary aspergillosis. However, subsequent testing confirmed Candida albicans infection; hence, we changed the antifungal agents effective for invasive candidiasis. This improved the patient's respiratory status, and he was then successfully weaned from mechanical ventilation. This case report highlights the importance of considering invasive candidiasis in the differential diagnosis of patients with bronchiectatic cavities on chest computed tomography, particularly in immunocompromised or critically ill patients with risk factors for invasive candidiasis.

Delayed diagnosis of severe diabetic ketoacidosis associated with a sodium-glucose cotransporter 2 inhibitor: a case report.

Sodium-glucose cotransporter 2 (SGLT2) inhibitors are used to treat patients with type 2 diabetes mellitus but may induce diabetic ketoacidosis (DKA). Owing to their pharmacological mechanisms, they cause a different pathogenesis to that of typical DKA and require special attention in terms of blood glucose concentrations and acidosis. We describe a case of prolonged acidosis because of failure to immediately discover the use of an SGLT2 inhibitor. Compared with typical DKA, SGLT2 inhibitor-associated DKA requires earlier and longer glucose supplementation. SGLT2 inhibitors are specific aetiological factors in DKA, and their use should be suspected when the patient presents with mild hyperglycaemia or prolonged acidosis.

The survival rate of patients with burns induced by explosions was significantly higher than that of common burn cases: A nationwide observational study using the Japan Trauma Data Bank.

BACKGROUNDS: Blast injuries have a variety of mechanisms, with some cases resulting in immediate death and others resulting in burns as a fourth type of blast injury when the energy of the explosion is relatively low. We reported in 2020, as an incidental result, that burns caused by explosions had a higher survival rate than usual burns caused by other mechanisms. The present study confirmed whether or not burns caused by explosions had higher survival rates than those caused by other mechanisms using the Japan Trauma Data Bank (JTDB), a leading nationwide trauma registry in Japan. METHODS: Burn patients registered to the JTDB database from January 2004 to March 2019 were analyzed retrospectively. The 338,744 patients registered to the JTDB database published in 2021 were identified. After exclusion, 7127 patients met the criteria for inclusion in this study. Logistic regression analyses were conducted for in-hospital survival rates using patients with burns, including cases complicated by usual trauma and burned patients without usual trauma. The survival rates by External burn grade AIS98 were compared between the explosion group and other cause groups using burn cases without usual trauma. RESULTS: The cause of the explosion significantly influenced the survival according to logistic regression analyses using burn groups with and without usual trauma. For AIS 4 and 5, we found significant differences between the explosion group and other cause groups in survival rates among burn cases without usual trauma. CONCLUSION: The survival rate of patients with burns induced by explosions was higher than that of common burn cases according to analyses based on a burn grade of AIS98 among burn cases without common trauma. Multivariate analyses also showed that explosion burns had a significantly better outcome than those induced by other causes.

Development of virtual reality content for learning Japan Prehospital Trauma Evaluation and Care initial assessment procedures.

Aim: The Japan Prehospital Trauma Evaluation and Care (JPTEC) is a standardized educational program for prehospital trauma care in Japan. The initial assessment in the JPTEC course comprises a training segment that includes a 30-min session. Given the limited face-to-face training due to the coronavirus disease 2019, virtual reality (VR) content has become an alternative. However, creating VR content typically requires the assistance of expert technicians. We aimed to create VR content for the initial assessment segment of the JPTEC and verify its educational effectiveness. Methods: We created VR content for learning the initial assessment of the JPTEC using our easy-to-use VR content creation system. The participants played the VR content for 15 min. The number of times they "cleared" (i.e., made a correct decision and completed the initial assessment) was recorded every 5 min. Then, a JPTEC-certified instructor tested their practical skills through face-to-face simulation. Results: The authors had no specialized skills and created the VR content in 2 days. Fourteen students used the material. They cleared the scenario 3 (3-4) times in the first 5 min in 15 min, 5 (4-5) times in the second 5 min, and 5 (5-5) times in the third 5 min (P < 0.05). All participants passed the practical evaluation. Conclusion: A shorter VR training developed using our easy-to-use VR content creation system can replace the 30-min JPTEC session on the initial assessment. This system allows for the free and easy creation of VR content.

Control of Burn Wound Infection by Methylene Blue-Mediated Photodynamic Treatment With Light-Emitting Diode Array Illumination in Rats.

BACKGROUND AND OBJECTIVES: Control of burn wound infection is difficult due to the increase in drug-resistant bacteria and deteriorated immune responses. In this study, we examined the usefulness of methylene blue (MB)-mediated antimicrobial photodynamic therapy (aPDT) with illumination by a light-emitting diode (LED) array for controlling invasive infections from the wound to inside the body for rats with an extended deep burn infected with Pseudomonas aeruginosa. STUDY DESIGN/MATERIALS AND METHODS: An MB solution with the addition of ethanol, ethylene-diamine-tetra-acetic acid disodium salt, and dimethyl sulfoxide was used as a photosensitizer (PS). An extended deep burn was made on the dorsal skin in rats and the wounds were infected with P. aeruginosa. The rats were divided into three groups: control (no treatment; n = 14), PS mixture application alone (PS alone group; n = 10), and aPDT group (n = 14). For aPDT, after the PS mixture was applied onto the surface of infected wounds, the wounds were illuminated with a 665-nm LED array at an intensity of 45 mW/cm2 three times per treatment, with an illumination duration of 20 minutes and an interval of 10 minutes. The treatment was repeated each day for 7 consecutive days (day 0-day 6). Bacterial numbers on the wound surface and the weights and survival rates of the animals were evaluated daily. At the endpoints, bacterial numbers in the liver and blood were counted. Since the PS mixture showed high dark toxicity against P. aeruginosa in vitro, the influence of the PS mixture application onto healthy skin was also examined in vivo. RESULTS: Even in the aPDT group, rapid bacterial regrowth was observed on the wound surface after each day's treatment, but the geometric mean values of the bacterial numbers before and after each aPDT were considerably lower than those in the control group. Application of the PS mixture alone showed a clear bactericidal effect only at day 0, which is attributable to the formation of biofilms after day 1. Rats in the aPDT group showed a smaller weight loss, a higher ratio of no bacterial migration at the endpoints, and significantly higher survival rates than those in the other two groups. Effects of repeated application of the PS mixture onto healthy skin were not evident. CONCLUSIONS: Application of MB-mediated aPDT with illumination by a high-intensity LED array daily for seven consecutive days was effective for suppressing invasive infection from the wound to inside the body in rats with an extensive deep burn infected with P. aeruginosa, resulting in significant improvement of their survival. Lasers Surg. Med. © 2021 Wiley Periodicals LLC.

Efficacy of Body Armor in Protection Against Blast Injuries Using a Swine Model in a Confined Space with a Blast Tube.

The purpose of this study was to clarify whether or not body armor would protect the body of a swine model using a blast tube built at National Defense Medical College, which is the first such blast tube in Japan. Seventeen pigs were divided into two groups: the body armor group and the non-body armor group. Under intravenous anesthesia, the pigs were tightly fixed in the left lateral position on a table and exposed from the back neck to the upper lumbar back to the blast wave and wind with or without body armor, with the driving pressure of the blast tube set to 3.0 MPa. When the surviving and dead pigs were compared, blood gas analyses revealed significant differences in PaO2, PaCO2, and pH in the super-early phase. All pigs injured by the blast wave and wind had lung hemorrhage. All 6 animals in the body armor group and 6 of the 11 animals in the control group survived for 3 hours after injury. Respiratory arrest immediately after exposure to the blast wave was considered to influence the mortality in our pig model. Body armor may have a beneficial effect in protecting against respiratory arrest immediately after an explosion.

The benefits of extrinsic ligament release for potentially hemodynamically unstable pancreaticoduodenal arcade aneurysm with median arcuate ligament syndrome: a case report.

BACKGROUND: A pancreaticoduodenal artery aneurysm (PDAA) occurring in close association with median arcuate ligament syndrome (MALS) is rare. A surgical procedure, such as median arcuate ligament (MAL) release, should be considered in such cases, but the operative criteria remain unknown. In this study, we reported an extremely rare case of PDAA with periarteritis nodosa (PAN) and MALS. CASE PRESENTATION: A 60-year-old man was transferred to our department with sudden onset of abdominal pain. We initially diagnosed his condition as a PDAA rupture with MALS based on enhanced computed tomography (CT). We promptly performed transcatheter arterial embolization (TAE) of PDAA, and the angiogram showed stagnant contrast agent in the celiac trunk, indicating total celiac artery occlusion. Follow-up enhanced CT three weeks after the first TAE clearly demonstrated newly formed, multiple aneurysms in the pancreaticoduodenal arcade and the hepatic artery. These findings indicated a systemic disorder, such as PAN or segmental arterial mediolysis, as the underlying cause. Therefore, we started corticosteroid therapy and performed diagnostic angiography to clarify the celiac artery's patency. Contrary to the initial angiography, the second angiography showed sustained blood flow in the celiac artery. Nevertheless, we performed both extrinsic MAL release and consecutive TAE because of the risk of multiple aneurysms rupturing due to an uncontrolled systemic disorder and consequent hepatic ischemia. The patient had no episode of recurrence until one year of follow-up. CONCLUSIONS: It is important to evaluate risk for hemodynamically unstable events to decide the best treatment strategy for MALS.

Fulminant pseudomembranous enterocolitis caused by Klebsiella oxytoca: an autopsy case report.

CASE: We describe a rare case of antibiotic-associated fulminant pseudomembranous enterocolitis caused by Klebsiella oxytoca. A 79-year-old man with a history of antibiotic therapy was admitted to our emergency department, complaining of consciousness disturbance. Initially, we suspected septic shock and diabetic ketoacidosis caused by intestinal infection. Although we administered sufficient extracellular fluid, his blood pressure was not elevated and his abdomen gradually swelled. OUTCOME: The patient died of shock and abdominal compartment syndrome. Autopsy revealed widespread jejunal necrosis in conjunction with colitis, suggesting fulminant pseudomembranous enterocolitis caused by K. oxytoca infection. CONCLUSION: As the clinical features of pseudomembranous enterocolitis caused by K. oxytoca resemble the features of colitis caused by Clostridium difficile, conservative therapy is applied first. However, fulminant pseudomembranous enterocolitis is a lethal disease, necessitating early operation for resection of the necrotic lesion. This report highlights the need for better surgical criteria at an early stage.

The Relationship between Functional Outcome and Prehospital Time Interval in Patients with Cerebral Infarction.

BACKGROUND: When symptoms of cerebral infarction are recognized in a patient, he or she should be transported to a hospital and should be started on the appropriate treatments. The effectiveness of delayed treatment of cerebral infarction with respect to the initial diagnosis or perception of the disease is still unclear. METHODS: We retrospectively investigated whether the functional outcomes would improve if patients with cerebral infarction were transported to the hospital with minimum delay. One-hundred twenty-two patients who were transported to Mishuku Hospital from January 2012 to August 2015 were included. We conducted multiple regression analyses. The criterion variable included the BI at discharge, and the explanatory variables were age, sex, days of hospital stay, the Barthel Index (BI) on admission, time from symptom onset to hospital arrival, time from emergency medical service perception to hospital arrival, recombinant tissue plasminogen activator (rt-PA) treatment, and the occluded artery type. RESULTS: In all 122 cases, the BI at the time of discharge was not related to onset time (P = .453) but was significantly related to perception time (P = .026). BI scores at discharge were high for young patients (P = .002) and for patients with short hospital stays (P <.001). In the rt-PA group (52 cases), BI scores at discharge were also high when the perception time was short (P = .036). CONCLUSIONS: A short interval between perception and hospital arrival improves the functional outcomes for patients with cerebral infarction. Thus, patients with cerebral infarctions must be treated with minimal delay after diagnosis of the condition.

The effect of adaptive servo-ventilation on dyspnoea, haemodynamic parameters and plasma catecholamine concentrations in acute cardiogenic pulmonary oedema.

BACKGROUND: Adaptive servo-ventilation has a potential sympathoinhibitory effect in acute cardiogenic pulmonary oedema (ACPO). AIMS: To evaluate the acute effects of adaptive servo-ventilation in patients with ACPO. METHODS: Fifty-eight consecutive patients with ACPO were divided into those who underwent adaptive servo-ventilation and those who received oxygen therapy alone as part of their immediate care. Visual analogue scale, vital signs, blood gas data and plasma catecholamine concentrations at baseline and 1 h during emergency care, and subsequent clinical events (death within 30 days, intubation within seven days or between seven and 30 days, and length of hospital stay) were assessed. Pre-matched and post-propensity score (PS)-matched datasets were analysed. RESULTS: During the first hour of adaptive servo-ventilation, plasma catecholamine concentrations fell significantly (baseline versus 1 h: epinephrine p = 0.003, norepinephrine p < 0.001, dopamine p < 0.001), with falls in blood pressure, heart rate, respiratory rate and pCO2, and rise in HCO3 and pH. In the PS-matched model, visual analogue scale (p = 0.036), systolic blood pressure (from 153.8 ± 30.7 to 133.1 ± 16.3 mmHg; p = 0.025) and plasma dopamine concentration (p = 0.034) fell significantly in the adaptive servo-ventilation group compared with the oxygen therapy alone group. The clinical outcomes between the groups were comparable. CONCLUSION: In patients with ACPO, emergency care using adaptive servo-ventilation attenuated plasma catecholamine concentrations and led to the improvement of dyspnoea, vital signs and acid-base balance, without adversely influencing clinical outcomes. Using adaptive servo-ventilation, rather than standard oxygen alone, may relieve dyspnoea and improve haemodynamic status, possibly by modulating sympathetic nerve activity.

Successful Plasma Exchange for Acute Pancreatitis Complicated With Hypertriglyceridemia: A Case Report.

A 33-year-old male with acute pancreatitis induced by hypertriglyceridemia had problems during treatment with plasma exchange. The hypercoagulable state was prevented by introducing innovative methods for cleaning and warming of the circuit and dialyzer. This enabled successful therapy, and the patient fully recovered from life-threatening acute pancreatitis.