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result(s) for
"Kanayama, Naohiro"
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Fibrinogen may aid in the early differentiation between amniotic fluid embolism and postpartum haemorrhage: a retrospective chart review
2021
This study aimed to determine whether blood loss and fibrinogen can differentiate amniotic fluid embolism (AFE) from postpartum haemorrhage (PPH). This retrospective case–control study included nine patients with clinical AFE (“AFE group”) and 78 patients with PPH managed at our tertiary care perinatal centre between January 2014 and March 2016. Patients meeting the Japanese diagnostic criteria for AFE were stratified into cardiopulmonary collapse-type AFE and disseminated intravascular coagulation (DIC)-type AFE groups. The relationship between blood loss and fibrinogen at onset was examined to compare DIC severity. Vital signs at onset were not significantly different. The AFE group had significantly less blood loss at onset (1506 mL vs 1843 mL, P = 0.0163), significantly more blood loss 2 h post-onset (3304 mL vs 1996 mL, P < 0.0001) and more severe coagulopathy and fibrinolysis. The blood loss/fibrinogen (B/F) ratio at onset was significantly higher in the DIC-type AFE group (23.15 ± 8.07 vs 6.28 ± 3.35 mL dL/mg, P < 0.0001). AFE was complicated by catastrophic DIC irrespective of blood loss at onset. Fibrinogen exhibited the strongest correlation among test findings at onset. The B/F ratio may help differentiate PPH from DIC-type AFE and diagnose clinical AFE, facilitating optimal replacement of coagulation factors during the early stages.
Journal Article
Piezoelectric Sensor-Based Continuous Monitoring of Respiratory Rate During Sleep
by
Divyanu Jain
,
Naohiro Kanayama
,
Shuhei So
in
Apnea
,
Biomedical Engineering and Bioengineering
,
Breathing
2021
Purpose
Respiration during sleep is one of the indicators of an individual’s health. However, many respiratory measurement devices need to be worn by the patient and can affect sleep. We introduce here a novel, easy-to-use, respiratory rate-monitoring sensor made of stretchable piezoelectric material that can be used conveniently at home as well as in a clinical setting.
Methods
We enrolled 6 members of a family as volunteers ranging in age from 9 months to 69 years. The sensor was used to continuously record respiratory rate data for all individuals during sleep.
Results
The sensor could detect known breathing patterns such as stable, unstable, or deep breathing as well as apnea during sleep. We observed significant differences in the respiratory rates and respiratory stability between subjects during sleep.
Conclusion
The piezoelectric sensor was effective in people in all age groups, paving a way for future use as a convenient and reliable mode of respiratory assessment for adults as well as neonates at home and in a clinical setting.
Journal Article
Pregnancy bias toward boys or girls: The Japan Environment and Children’s Study
2023
The sex of the conceived child is a significant concern for parents. To verify whether there women have pregnancy bias toward boys or girls, we investigated whether the history of continuous same-sex pregnancy was associated with the subsequent child’s sex. We prospectively analyzed data from the Japan Environment and Children’s Study, a birth cohort study. We included all cases of singleton live births (n = 98 412). Women with pregnancy due to infertility treatment were excluded (n = 6255); Similarly, women with a history of miscarriage, artificial abortion, stillbirth, and multiple pregnancies, and those with missing data on the sex of the previous child were excluded. Altogether, 62 718 women were included. For the first live birth, a male-biased sex ratio of 1.055 was observed. Further, no significant difference was found in the sex ratio of the conceived child between women with one boy and those with one girl previously. However, when there were more than two children previously, the subsequently conceived child’s male/female sex ratio was significantly higher among boy-only mothers than among girl-only mothers. The results indicated that several pregnant women are biased toward conceiving either boys or girls.
Journal Article
Comparative analysis of hyperfibrinolysis with activated coagulation between amniotic fluid embolism and severe placental abruption
by
Matsumoto, Masako
,
Itoh, Hiroaki
,
Todo, Yusuke
in
692/1807/2782
,
692/699/2732
,
Abruptio Placentae
2024
Amniotic fluid embolism (AFE) and placental abruption (PA) are typical obstetric diseases associated with disseminated intravascular coagulation (DIC). AFE is more likely to be complicated with enhanced fibrinolysis than PA. AFE may have an additional mechanism activating fibrinolytic cascade. We aimed to compare the coagulation/fibrinolysis factors among AFE, PA, and peripartum controls. We assessed AFE cases registered in the Japanese AFE Registry, and PA cases complicated with DIC (severe PA) and peripartum controls recruited at our hospital. The following factors in plasma were compared: prothrombin fragment 1 + 2 (PF1 + 2), plasmin α2-plasmin inhibitor complex (PIC), tissue factor (TF), tissue plasminogen activator (tPA), annexin A2 (AnnA2), total thrombin activatable fibrinolysis inhibitor (TAFI) including its activated form (TAFIa), and plasminogen activator inhibitor-type 1 (PAI-1). PF1 + 2 and PIC were markedly increased in both AFE (n = 27) and severe PA (n = 12) compared to controls (n = 23), without significant difference between those disease groups; however, PIC in AFE showed a tendency to elevate relative to PF1 + 2, compared with severe PA. AFE had significantly increased tPA and decreased total TAFI levels compared with severe PA and controls, which might be associated with further plasmin production in AFE and underlie its specific fibrinolytic activation pathway.
Journal Article
Current status of pregnancy-related maternal mortality in Japan: a report from the Maternal Death Exploratory Committee in Japan
by
Ishiwata, Isamu
,
Murakoshi, Takeshi
,
Osato, Kazuhiro
in
Accidental deaths
,
Adult
,
Blood transfusions
2016
ObjectiveTo clarify the problems related to maternal deaths in Japan, including the diseases themselves, causes, treatments and the hospital or regional systems.DesignDescriptive study.SettingMaternal death registration system established by the Japan Association of Obstetricians and Gynecologists (JAOG).ParticipantsWomen who died during pregnancy or within a year after delivery, from 2010 to 2014, throughout Japan (N=213).Main outcome measuresThe preventability and problems in each maternal death.ResultsMaternal deaths were frequently caused by obstetric haemorrhage (23%), brain disease (16%), amniotic fluid embolism (12%), cardiovascular disease (8%) and pulmonary disease (8%). The Committee considered that it was impossible to prevent death in 51% of the cases, whereas they considered prevention in 26%, 15% and 7% of the cases to be slightly, moderately and highly possible, respectively. It was difficult to prevent maternal deaths due to amniotic fluid embolism and brain disease. In contrast, half of the deaths due to obstetric haemorrhage were considered preventable, because the peak duration between the initial symptoms and initial cardiopulmonary arrest was 1–3 h.ConclusionsA range of measures, including individual education and the construction of good relationships among regional hospitals, should be established in the near future, to improve primary care for patients with maternal haemorrhage and to save the lives of mothers in Japan.
Journal Article
A Case of Consumptive Coagulopathy Before Cardiopulmonary Failure in Amniotic Fluid Embolism and Review of Literature: A Perspective of the Latent Onset and Progression of Coagulopathy
by
Itoh, Hiroaki
,
Itoh, Toshiya
,
Kubota, Naohiro
in
Amniotic fluid
,
Blood pressure
,
Cardiac arrhythmia
2024
Amniotic fluid embolism (AFE) induces cardiopulmonary insufficiency with consumptive coagulopathy. Previous studies reported that refractory coagulopathy has already advanced at the onset of maternal cardiovascular and/or respiratory symptoms. However, when the consumption of coagulation factors starts during the clinical course, AFE remains to be elucidated. We report an intrapartum AFE case of consumptive coagulopathy before dyspnea with hypotension developing during urgent cesarean delivery that was revealed by non-reassuring fetal heart rate tracing. The patient, a 42-year-old multiparous parturient, underwent induced labor after a premature rupture of membranes in week 39 of pregnancy. Coagulation screening was initially within the normal range. Fetal heart rate monitoring demonstrated bradycardia coincided with uterine tachysystole after three hours, which required urgent cesarean section with preoperative blood screening. The hemoglobin level was maintained at 129 g/L; however, the fibrinogen value reduced to 1.79 g/L with D-dimer elevation over 60 µg/mL. Ninety minutes later, she developed dyspnea with hypotension at suturing hysterotomy. At the end of surgery, her fibrinogen further decreased to below 0.3 g/L with prolonged prothrombin time. After vigorous intensive care, she was discharged without sequelae. Consumptive coagulopathy may initiate and progress before apparent cardiopulmonary symptoms in some AFE cases. Non-reassuring fetal heart rate tracing concomitant with abrupt uterine tachysystole and/or hypertonus may be an earlier time point for the detection and intervention of AFE-related coagulopathy.
Journal Article
Prevention of fetal brain injury in category II tracings
by
Nakai, Akihito
,
Magawa, Shoichi
,
Kanayama, Naohiro
in
Acidosis
,
Acidosis - prevention & control
,
base excess
2023
Introduction With category II fetal heart rate tracings, the preferred timing of interventions to prevent fetal hypoxic brain damage while limiting operative interventions remains unclear. We aimed to estimate fetal extracellular base deficit (BDecf) during labor with category II tracings to quantify the timing of potential interventions to prevent severe fetal metabolic acidemia. Material and methods A longitudinal study was conducted using the database of the Recurrence Prevention Committee, Japan Obstetric Compensation System for Cerebral Palsy, including infants with severe cerebral palsy born at ≥34 weeks' gestation between 2009 and 2014. Cases included those presumed to have an intrapartum onset of hypoxic–ischemic insult based on the fetal heart rate pattern evolution from reassuring to an abnormal pattern during delivery, in association with category II tracings marked by recurrent decelerations and an umbilical arterial BDecf ≥ 12 mEq/L. BDecf changes during labor were estimated based on stages of labor and the frequency/severity of fetal heart rate decelerations using the algorithm of Ross and Gala. The times from the onset of recurrent decelerations to BDecf 8 and 12 mEq/L (Decels‐to‐BD8, Decels‐to‐BD12) and to delivery were determined. Cases were divided into two groups (rapid and slow progression) based upon the rate of progression of acidosis from onset of decelerations to BDecf 12 mEq/L, determined by a finite‐mixture model. Results The median Decels‐to‐BD8 (28 vs. 144 min, p < 0.01) and Decels‐to‐BD12 (46 vs. 177 min, p < 0.01) times were significantly shorter in the rapid vs slow progression. In rapid progression cases, physicians' decisions to deliver the fetus occurred at ~BDecf 8 mEq/L, whereas the “decisions” did not occur until BDecf reached 12 mEq/L in slow progression cases. Conclusions Fetal BDecf reached 12 mEq/L within 1 h of recurrent fetal heart rate decelerations in the rapid progression group and within 3 h in the slow progression group. These findings suggest that cases with category II tracings marked by recurrent decelerations (i.e., slow progression) may benefit from operative intervention if persisting for longer than 2 h. In contrast, cases with sudden bradycardia (i.e., rapid progression) represent a challenge to prevent severe acidosis and hypoxic brain injury due to the limited time opportunity for emergent delivery. Fetal base deficit analysis suggests labor intervention for slowly evolving category II tracings with recurrent decelerations over 2 h may prevent hypoxic brain damage. In contrast, cases with sudden bradycardia represent a challenge to prevent severe acidosis and brain injury.
Journal Article
Maternal diaphragmatic hernia in mid-pregnancy
by
Kawai, Kenta
,
Isomura-Furuta, Naomi
,
Itoh, Hiroaki
in
Case reports
,
Health risk assessment
,
Hernia
2018
Journal Article
Gross appearance of the fetal membrane on the placental surface is associated with histological chorioamnionitis and neonatal respiratory disorders
by
Matsumoto, Masako
,
Uchida, Toshiyuki
,
Itoh, Hiroaki
in
Adolescent
,
Adult
,
Bacterial infections
2020
An opaque fetal membrane based on gross appearance is traditionally indicative of histological chorioamnionitis; however, to the best of our knowledge, there is currently no supportive evidence, and its diagnostic efficiency has not yet been scientifically demonstrated. The present study aimed to provide scientific insights into the traditional concept of an opaque fetal membrane based on gross appearance being an indicator of histological chorioamnionitis. We examined the placental pathology after screening of the placental gross appearance and perinatal complications and did not examine uncomplicated deliveries. We investigated the relationship between the presence of an opaque fetal membrane and histological chorioamnionitis (Cohort 1, 571 placentas) or the outcomes of neonates delivered at term (Cohort 2, 409 placentas) at Hamamatsu University School of Medicine between 2010 and 2017. The judgment of a positive opaque fetal membrane based on gross appearance correlated with histological chorioamnionitis (Cohort 1). Its sensitivity and specificity were 66.7 and 89.9%, respectively, while positive and negative predictive values were 86.8 and 73.0%, respectively. The judgment of a positive opaque fetal membrane based on gross appearance significantly correlated with chorioamnionitis-related complications in term newborns after adjustments for confounding factors (OR;1.82 [1.07–3.11], P<0.05) (Cohort 2). A correlation was observed even after adjustments for confounding factors. The present study is the first to demonstrate that the judgment of a positive opaque fetal membrane based on gross appearance correlated with histological chorioamnionitis as well as chorioamnionitis-related complications in newborns delivered at term. The present results provide support for the traditionally-described importance of gross inspections for an opaque fetal membrane soon after birth.
Journal Article
Endogenously Generated Plasmin at the Vascular Wall Injury Site Amplifies Lysine Binding Site-Dependent Plasminogen Accumulation in Microthrombi
2015
The fibrinolytic system plays a pivotal role in the regulation of hemostasis; however, it remains unclear how and when the system is triggered to induce thrombolysis. Using intra-vital confocal fluorescence microscopy, we investigated the process of plasminogen binding to laser-induced platelet-rich microthrombi generated in the mesenteric vein of transgenic mice expressing green fluorescent protein (GFP). The accumulation of GFP-expressing platelets as well as exogenously infused Alexa Fluor 568-labeled Glu-plasminogen (Glu-plg) on the injured vessel wall was assessed by measuring the increase in the corresponding fluorescence intensities. Glu-plg accumulated in a time-dependent manner in the center of the microthrombus, where phosphatidylserine is exposed on platelet surfaces and fibrin formation takes place. The rates of binding of Glu-plg in the presence of ε-aminocaproic acid and carboxypeptidase B, as well as the rates of binding of mini-plasminogen lacking kringle domains 1-4 and lysine binding sites, were significantly lower than that of Glu-plg alone, suggesting that the binding was dependent on lysine binding sites. Furthermore, aprotinin significantly suppressed the accumulation of Glu-plg, suggesting that endogenously generated plasmin activity is a prerequisite for the accumulation. In spite of the endogenous generation of plasmin and accumulation of Glu-plg in the center of microthrombi, the microthrombi did not change in size during the 2-hour observation period. When human tissue plasminogen activator was administered intravenously, Glu-plg further accumulated and the microthrombi were lysed. Glu-plg appeared to accumulate in the center of microthrombi in the early phase of microthrombus formation, and plasmin activity and lysine binding sites were required for this accumulation.
Journal Article