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Dive into the research topics where Motoyasu Yamazaki is active.

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Featured researches published by Motoyasu Yamazaki.


Burns | 2001

Elevation of plasma free PAI-1 levels as an integrated endothelial response to severe burns

Katsunori Aoki; Naoki Aikawa; Kazuhiko Sekine; Motoyasu Yamazaki; Takuya Mimura; Tetsumei Urano; Akikazu Takada

To clarify the role of plasminogen activator inhibitor type 1 (PAI-1) in postburn hypercoagulation, we assayed the plasma levels of tissue-type plasminogen activator (t-PA) antigen, total PAI-1 antigen, and total t-PA-PAI-1 complex in 15 burned patients. The total body surface area of the burn injury ranged from 30 to 80%. Serial blood samples were collected from 12 to 168 h following the thermal injury. The plasma t-PA level and the free PAI-1 level increased significantly in the immediate postburn period, and the percent increase in the latter over the values in the healthy controls was much greater than that of the former. The ratio of the concentrations of t-PA-PAI-1 complex to free PAI-1 decreased throughout the 7 postburn days. The fact that the decreases in this ratio clearly showed no dissociation of the euglobulin fraction suggests that the postburn hypofibrinolysis occurred as a result of increased synthesis of PAI-1. On the other hand, changes in several parameters of the coagulation or fibrinolysis system and in plasma thrombomodulin showed that postburn hypercoagulability is associated with secondary hyperfibrinolysis with no evidence of vascular endothelial injury. The paradoxical coexistence of postburn hyper- and hypofibrinolysis is a good reflection of the character of PAI-1, which is a biphasic protein that is both a functional protein and an acute phase reactant. Thus, increased synthesis of PAI-1 may not enhance postburn hypercoagulability to create a coagulation-dominant type of disseminated intravascular coagulation severe enough to trigger multiple organ dysfunction syndrome. In conclusion, increased synthesis of PAI-1 in the initial postburn period reflects an integrated endothelial response to burn stress, and because it is a functional protein, the concentration of free PAI-1 antigen may be an important index for predicting secondary consumption coagulopathy.


Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine | 2013

Digital video recording in trauma surgery using commercially available equipment

Shokei Matsumoto; Kazuhiko Sekine; Motoyasu Yamazaki; Tomohiro Funabiki; Tomohiko Orita; Masayuki Shimizu; Mitsuhide Kitano

IntroductionAlthough videos of surgical procedures are useful as an educational tool, the recording of trauma surgeries in emergency situations is difficult. We describe an inexpensive and practical shooting method using a commercially available head-mounted video camera.MethodsWe used a ContourHD 1080p Helmet Camera (Contour Inc., Seattle, Washington, USA.). This small, self-contained video camera and recording system was originally designed for easy videography of outdoor sports by participants.ResultsWe were able to easily make high-quality video recordings of our trauma surgeries, including an emergency room thoracotomy for chest stab wounds and a crush laparoptomy for a severe liver injury.ConclusionThere are currently many options for recording surgery in the field, but the recording device and system should be chosen according to the surgical situation. We consider the use of a helmet-mounted, self-contained high-definition video camera-recorder to be an inexpensive, quick, and easy method for recording trauma surgeries.


Journal of Trauma-injury Infection and Critical Care | 2010

Predictive value of a flat inferior vena cava on initial computed tomography for hemodynamic deterioration in patients with blunt torso trauma.

Shokei Matsumoto; Kazuhiko Sekine; Motoyasu Yamazaki; Kenihiro Sasao; Tomohiro Funabiki; Masayuki Shimizu; Hiroshi Yoshii; Masanobu Kishikawa; Mitsuhide Kitano

BACKGROUND We aimed to investigate the value of the diameter of the inferior vena cava (IVC) on initial computed tomography (CT) to predict hemodynamic deterioration in patients with blunt torso trauma. METHODS We reviewed the initial CT scans, taken after admission to emergency room (ER), of 114 patients with blunt torso trauma who were consecutively admitted during a 24-month period. We measured the maximal anteroposterior and transverse diameters of the IVC at the level of the renal vein. Flat vena cava (FVC) was defined as a maximal transverse to anteroposterior ratio of less than 4:1. According to the hemodynamic status, the patients were categorized into three groups. Patients with hemodynamic deterioration after the CT scans were defined as group D (n = 37). The other patients who remained hemodynamically stable after the CT scans were divided into two groups: patients who were hemodynamically stable on ER arrival were defined as group S (n = 60) and those who were in shock on ER arrival and responded to the fluid resuscitation were defined as group R (n = 17). RESULTS The anteroposterior diameter of the IVC in group D was significantly smaller than those in groups R and S (7.6 mm ± 4.4 mm, 15.8 mm ± 5.5 mm, and 15.3 mm ± 4.2 mm, respectively; p < 0.05). Of the 93 patients without FVC, 16 (17%) were in group D, 14 (15%) required blood transfusion, and 8 (9%) required intervention. However, of the 21 patients with FVC, all patients were in group D, 20 (95%) required blood transfusion, and 17 (80%) required intervention. The patients with FVC had higher mortality (52%) than the other patients (2%). CONCLUSION In cases of blunt torso trauma, patients with FVC on initial CT may exhibit hemodynamic deterioration, necessitating early blood transfusion and therapeutic intervention.


Burns | 2010

A comparison of Ringer's lactate and acetate solutions and resuscitative effects on splanchnic dysoxia in patients with extensive burns

Katsunori Aoki; Atsuto Yoshino; Kikuo Yoh; Kazuhiko Sekine; Motoyasu Yamazaki; Naoki Aikawa

We compared the effects of Ringers lactate (RL) and acetate (RA) solutions on parameters of splanchnic dysoxia such as PgCO(2) (PCO(2) of gastric mucosa) and pH(i) (pH of gastric mucosa) using a gastric tonometer, in addition to blood markers such as the serum arterial level of lactate, base excess, ketone body ratio, and antithrombin during the first 72h of the resuscitation period in patients with burns covering 30% or more of their body surface. A prospective study was conducted in the university tertiary referral centers. There were no significant differences in the average age, TBSA (total burn surface area), and resuscitative fluid volume during the first and second 24h between the two groups. In the RA group, PCO(2) gap values calculated employing the formula: PgCO(2)-PaCO(2) (arterial PCO(2)), and pH gap calculated by: pH(a) (arterial pH)-pH(i), improved to the normal ranges at 24 h postburn, which was significantly faster than in the RL group. On the other hand, there were no significant differences in blood parameters between the two groups over the course. These results suggest that fluid resuscitation with RA may more rapidly ameliorate splanchnic dysoxia, as evidenced by gastric tonometry, compared to that with RL.


American Journal of Emergency Medicine | 2015

Chest tube insertion direction: is it always necessary to insert a chest tube posteriorly in primary trauma care?

Shokei Matsumoto; Kazuhiko Sekine; Tomohiro Funabiki; Motoyasu Yamazaki; Tomohiko Orita; Masayuki Shimizu; Kei Hayashida; Masanobu Kishikawa; Mitsuhide Kitano

BACKGROUND The advanced trauma life support guidelines suggest that, in primary care, the chest tube should be placed posteriorly along the inside of the chest wall. A chest tube located in the posterior pleural cavity is of use in monitoring the volume of hemothoraces. However, posterior chest tubes have a tendency to act as nonfunctional drains for the evacuation of pneumothoraces, and additional chest tube may be required. Thus, it is not always necessary to insert chest tubes posteriorly. The purpose of this study was to determine whether posterior chest tubes are unnecessary in trauma care. METHODS We reviewed the volume of hemothoraces from 78 chest drains emergently placed posteriorly at a primary trauma care in 75 blunt chest trauma patients who were consecutively admitted over a 6-year period, excluding those with cardiopulmonary arrest and occult pneumothoraces. Massive acute hemothorax (MAH), in which the chest tube should be inserted posteriorly, was defined as the evacuation of more than 500 mL of blood or the need for hemostatic intervention within 24 hours of trauma admission. Demographics, interventions, and outcomes were analyzed. We also reviewed the malpositioning of 74 chest tubes based on anterior and posterior insertion directions in patients who subsequently underwent computed tomography. RESULTS The overall incidence of MAH was 23% (n = 18). In the univariate analysis, the presence of multiple rib fractures, shock, pulmonary opacities on chest x-ray, and the need for intubation were found to be independent predictors for the development of MAH. If all 4 independent predictors were absent, none of the patients developed MAH. The incidence of nonfunctional chest drains that required reinsertion or the addition of a new drainage was 27% (n = 20). The rates of both radiologic and functional malposition in chest tubes with posterior insertion were significantly higher than in patients with anterior insertion (64% and 43% vs 13% and 6%, respectively; P < .01). CONCLUSIONS Chest tubes did not need to be directed posteriorly in many trauma cases. Posterior chest tubes have a high incidence of being malpositioned. This malpositioning may be prevented by judging the necessity for posterior insertion.


Intensive Care Medicine | 1999

A case of traumatic shock complicated by methamphetamine intoxication

T. Horiguchi; S. Hori; Y. Shinozawa; S. Fujishima; Hiroyuki Kimura; M. Yokoyama; Junichi Sasaki; Seiji Takatsuki; Masaru Suzuki; Motoyasu Yamazaki; Naoki Aikawa

Abstract A case of a 38-year-old male with traumatic shock complicated by methamphetamine intoxication is presented. The patient was involved in an assault which resulted in cardiac tamponade and right ventricular outflow laceration. Pericardiocentesis was immediately performed. However, profound metabolic acidosis greatly in excess of that expected from the short duration of the shock was revealed by arterial blood gas analysis. Another cause of the metabolic acidosis was suspected. The patient subsequently admitted to intravenous use of methamphetamine. Following hemodynamic and metabolic stabilization by continuous pericardial drainage and intravenous administration of sodium bicarbonate, the patient underwent cardiac surgery. His postoperative course was uneventful. There is a substantial association between methamphetamine users and traumatic accidents. In such cases, early identification of drug use is important. Marked metabolic acidosis, which conflicts with the diagnosed cause of shock, may be a clinical clue to methamphetamine intoxication.


Shock | 2017

Clinical Evaluation of "Shock Bowel" Using Intestinal Fatty Acid Binding Protein.

Shokei Matsumoto; Kazuhiko Sekine; Hiroyuki Funaoka; Tomohiro Funabiki; Taku Akashi; Kei Hayashida; Masayuki Shimizu; Tomohiko Orita; Motoyasu Yamazaki; Mitsuhide Kitano

ABSTRACT “Shock bowel” is one of the computed tomographic (CT) signs of hypotension, yet its clinical implications remain poorly understood. We evaluated how shock bowel affects clinical outcomes and the extent of intestinal epithelial damage in trauma patients by measuring the level of intestinal fatty acid binding protein (I-FABP). We reviewed the initial CT scans, taken in the emergency room, of 92 patients with severe blunt torso trauma who were consecutively admitted during a 24-month period. The data collected included CT signs of hypotension, I-FABP, feeding intolerance, and other clinical outcomes. Demographic and clinical outcomes were compared in patients with and without hemodynamic shock and shock bowel. Shock bowel was found in 16 patients (17.4%); of them 7 patients (43.8%) did not have hemodynamic shock. Certain CT signs of hypotension, namely free peritoneal fluid, contrast extravasation, small-caliber aorta, and shock bowel, were significantly more common in patients with hemodynamic shock than in patients without (P < 0.05). Injury severity score and the rate of consciousness disturbance were significantly higher in patients with shock bowel than in patients without (P < 0.05). The rate of feeding intolerance and median plasma I-FABP levels were significantly higher in patients with shock bowel than in patients without (75.0% vs. 22.4%, P < 0.001 and 17.0 ng/mL vs. 3.7 ng/mL, P < 0.001, respectively). There was no difference in mortality. In conclusion, shock bowel is not always due to hemodynamic shock. It does, however, indicate severe intestinal mucosal damages and may predict feeding intolerance.


American Journal of Surgery | 2016

Diagnostic value of intestinal fatty acid-binding protein for pneumatosis intestinalis

Shokei Matsumoto; Kazuhiko Sekine; Hiroyuki Funaoka; Tomohiro Funabiki; Motoyasu Yamazaki; Tomohiko Orita; Kei Hayashida; Mitsuhide Kitano

BACKGROUND Pneumatosis intestinalis (PI) is known as a sign of a life-threatening bowel ischemia. We aimed to evaluate the utility of intestinal fatty acid-binding protein (I-FABP) in the diagnosis of pathologic PI. METHODS All consecutive patients who presented to our emergency department with PI were prospectively enrolled. The diagnostic performance of I-FABP for pathologic PI was compared with that of other traditional biomarkers and various parameters. RESULTS Seventy patients with PI were enrolled. Pathologic PI was diagnosed in 27 patients (39%). The levels of most biomarkers were significantly higher in patients with pathologic PI than those with nonpathologic PI (P < .05). Receiver operator characteristic analysis revealed that the area under the curve (AUC) was highest for I-FABP (area under the curve = .82) in the diagnosis of pathologic PI. CONCLUSIONS High I-FABP value, in combination with other parameters, might be clinically useful for pathologic PI.


World Journal of Emergency Surgery | 2016

Diagnostic accuracy of oblique chest radiograph for occult pneumothorax: comparison with ultrasonography

Shokei Matsumoto; Kazuhiko Sekine; Tomohiro Funabiki; Tomohiko Orita; Masayuki Shimizu; Kei Hayashida; Taku Kazamaki; Tatsuya Suzuki; Masanobu Kishikawa; Motoyasu Yamazaki; Mitsuhide Kitano

BackgraoundAn occult pneumothorax is a pneumothorax that is not seen on a supine chest X-ray but is detected by computed tomography scanning. However, critical patients are difficult to transport to the computed tomography suite. We previously reported a method to detect occult pneumothorax using oblique chest radiography (OXR). Several authors have also reported that ultrasonography is an effective technique for detecting occult pneumothorax. The aim of this study was to evaluate the usefulness of OXR in the diagnosis of the occult pneumothorax and to compare OXR with ultrasonography.MethodsAll consecutive blunt chest trauma patients with clinically suspected pneumothorax on arrival at the emergency department were prospectively included at our tertiary-care center. The patients underwent OXR and ultrasonography, and underwent computed tomography scans as the gold standard. Occult pneumothorax size on computed tomography was classified as minuscule, anterior, or anterolateral.ResultsOne hundred and fifty-nine patients were enrolled. Of the 70 occult pneumothoraces found in the 318 thoraces, 19 were minuscule, 32 were anterior, and 19 were anterolateral. The sensitivity and specificity of OXR for detecting occult pneumothorax was 61.4 % and 99.2 %, respectively. The sensitivity and specificity of lung ultrasonography was 62.9 % and 98.8 %, respectively. Among 27 occult pneumothoraces that could not be detected by OXR, 16 were minuscule and 21 could be conservatively managed without thoracostomy.ConclusionOXR appears to be as good method as lung ultrasonography in the detection of large occult pneumothorax. In trauma patients who are difficult to transfer to computed tomography scan, OXR may be effective at detecting occult pneumothorax with a risk of progression.


Journal of Trauma-injury Infection and Critical Care | 2012

A quick and easy closure technique for abdominal stab wound after diagnostic laparoscopy.

Shokei Matsumoto; Kazuhiko Sekine; Motoyasu Yamazaki; Tomohiro Funabiki; Masayuki Shimizu; Mitsuhide Kitano

Mandatory laparotomy for patients with abdominal stab wounds (ASWs) not only allows for the early detection of some expected injuries but also results in a higher unnecessary laparotomy rate, longer hospital stays, and increased hospital costs.1,2 Delayed laparotomy, however, increases mortality and morbidity. Therefore, the decision regarding when to operate on a patient with an ASW remains a challenge. Recent reports have demonstrated that diagnostic laparoscopy (DL) is useful for ASWs.3–5 In Japan, more than half of ASW patients are associated with suicide attempts because of psychiatric illnesses or mental disorders.6 Under these circumstances, physical examinations are sometimes unreliable so that DL should be frequently used in these patients. Even if DL prevents unnecessary laparotomy, it remains possible that these ASWs may subsequently develop ventral hernias.7,8 In addition, some cases of ASWs require an extended local wound that is as long as a laparotomy for direct fascial closure. Here, we report the laparoscopic repair of the abdominal wall using an Endoclose suturing device (Covidien, Mansfield, MA) when laparotomy is not needed according to DL.

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Hideki Ishikawa

Kyoto Prefectural University of Medicine

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