Shinichi Ishimatsu

Report on 640 victims of the Tokyo subway sarin attack

Abstract [Okumura T, Takasu N, Ishimatsu S, Miyanoki S, Mitsuhashi A, Kumada K, Tanaka K, Hinohara S: Report on 640 victims of the Tokyo subway sarin attack. Ann Emerg Med August 1996;28:129-135.] See related editorial, Chemical Agent Terrorism.

Asymptomatic sequelae to acute sarin poisoning in the central and autonomic nervous system 6 months after the Tokyo subway attack

Abstract Six to eight months after the Tokyo subway attack in March 1995, the neurophysiological effects of acute sarin poisoning were investigated in 18 passengers exposed to sarin (sarin cases) in the subways to ascertain the focal or functional brain deficits induced by sarin. The event-related and visual evoked potentials (P300 and VEP), brainstem auditory evoked potential, and electrocardiographic R-R interval variability (CVRR), together with the score on the posttraumatic stress disorder (PTSD) checklist, were measured in the sarin cases and the same number of control subjects matched for sex and age. None of the sarin cases had any obvious clinical abnormalities at the time of testing. The P300 and VEP (P100) latencies in the sarin cases were significantly prolonged compared with the matched controls. In the sarin cases, the CVRR was significantly related to serum cholinesterase (ChE) levels determined immediately after exposure; the PTSD score was not significantly associated with any neurophysiological data despite the high PTSD score in the sarin cases. These findings suggest that asymptomatic sequelae to sarin exposure, rather than PTSD, persist in the higher and visual nervous systems beyond the turnover period of ChE; sarin may have neurotoxic actions in addition to the inhibitory action on brain ChE.

Chronic neurobehavioral effects of Tokyo subway sarin poisoning in relation to posttraumatic stress disorder.

Chronic neurobehavioral effects of acute sarin poisoning were evaluated in 9 male and 9 female patients who were exposed to sarin poisoning in the Tokyo subway incident in Japan. The investigators used nine neurobehavioral tests, as well as a posttraumatic stress disorder checklist, 6-8 mo after the poisoning occurred. Serum cholinesterase activity in patients on the day of poisoning (i.e., March 20, 1995) ranged from 13 to 131 IU/l (mean=72.1 IU/l). The results of analysis covariance, in which age, education level, alcohol consumption, and smoking status (covariates) were controlled in 18 sarin cases and in 18 controls, showed that the score on the digit symbol (psychomotor performance) test was significantly lower in the sarin cases than in controls. Nonetheless, the scores for the General Health Questionnaires, fatigue of Profile of Mood States, and posttraumatic stress disorder checklist were significantly higher in the sarin cases than controls. The investigators added posttraumatic stress disorder to the covariates, and only the score on the digit symbol test was significantly lower in sarin cases. In addition, the results of stepwise multiple regression analysis in 18 sarin cases revealed that scores for the General Health Questionnaires, fatigue of Profile of Mood States (i.e., fatigue, tension-anxiety, depression, and anger-hostility)-together with the paired-associate learning test-were associated significantly with posttraumatic stress disorder. The association did not remain significant for the digit symbol test score. Perhaps a chronic effect on psychomotor performance was caused directly by acute sarin poisoning; on the other hand, the effects on psychiatric symptoms (General Health Questionnaire) and fatigue (Profile of Mood States) appeared to result from posttraumatic stress disorder induced by exposure to sarin.

The relationship of short-term air pollution and weather to ED visits for asthma in Japan

INTRODUCTION The incidence of asthma exacerbation has been increasing in many countries. Environmental factors may play an important role in this trend. We aimed to investigate the relationship of weather conditions and air pollution to significant exacerbation of asthma. METHODS The daily number of emergency department (ED) visits by ambulance for asthma was collected through records of the Tokyo Fire Department from January 1 to December 31, 2005. We also collected daily air pollution levels and meteorological data for Tokyo during the same period. Meteorological data included minimum temperature, maximum barometric pressure, maximum relative humidity, and precipitation. Measured air pollutants included sulfur dioxide, nitrogen monoxide, nitrogen oxides, suspended particulate matter, and carbon monoxide. We performed a time series analysis using multivariable-adjusted autoregressive integrated moving average model. The analysis was conducted separately among adults and among children (<15 years old). RESULTS Of a total of 643,849 patients who were transported to the ED by ambulance, there were 6447 patients with exacerbation of asthma. Among adults, lower minimum temperature was significantly associated with increased transport. Among children, there were no significant associations between exacerbation of asthmas requiring emergency transport and air pollutants or meteorological factors. The highest number of transports was found on October 11, the day after the National Sports Day in Japan. CONCLUSIONS Cold temperature is related to an increased risk of significant exacerbation of asthma in adults. Air pollution does not seem to play a major role in significant exacerbation of asthma requiring ambulance transports to ED.

Chronic neurobehavioral and central and autonomic nervous system effects of Tokyo subway sarin poisoning.

To evaluate delayed (prolonged) neurobehavioral and neurophysiological effects of acute sarin poisoning, nine male and nine female patients of the Tokyo subway sarin poisoning in Japan were examined by neurobehavioral tests, posttraumatic stress disorder (PTSD) checklist, brain evoked potentials, computerized static posturography, and electrocardiographic R-R interval variability, 6-8 months after the poisoning. Their serum cholinesterase activities on the day of the poisoning (March 20, 1995) were 13-131 (mean 72.1) IU/L. The results suggested delayed effects on psychomotor performance, the higher and visual nervous system and the vestibulo-cerebellar system with psychiatric symptoms resulting from PTSD.

A preliminary study on delayed vestibulo-cerebellar effects of Tokyo Subway Sarin Poisoning in relation to gender difference: frequency analysis of postural sway.

To evaluate delayed (long-term) effects of acute sarin poisoning on postural balance, nine male and nine female victims of the Tokyo Subway Sarin Poisoning in Japan (sarin cases) were examined by computerized posturography 6-8 months after the poisoning. Their plasma cholinesterase activities (ChE) on the day of the poisoning (March 20, 1995) were 13-95 (mean 68.2) IU/l for females and 19-131 (mean 75.9) IU/l for males, which were not significantly different between the two sexes. In females, the postural sway of low frequency (0-1 Hz) in the anterior-posterior direction and area of sway with eyes open was significantly larger in the cases than in the controls. Romberg quotients for the low-frequency sway in the anterior-posterior direction for females and low-frequency sway and length of sway in the medio-lateral direction for males were significantly related to log ChE. It is suggested that a delayed effect on the vestibulo-cerebellar system was induced by acute sarin poisoning; females might be more sensitive than males.

Prediction protocol for neurological outcome for survivors of out-of-hospital cardiac arrest treated with targeted temperature management ☆

AIM To identify patients who can obtain the full benefit from targeted temperature management (TTM) after out-of-hospital cardiac arrest. METHODS We performed a retrospective observational study of comatose patients treated with TTM after an out-of-hospital cardiac arrest from January 2006 to February 2011. Neurological outcome was evaluated with the Glasgow-Pittsburgh Cerebral Performance category (CPC) at discharge and predictors were determined. RESULTS Of 66 patients studied, 40 (60.6%) survived to neurologically intact discharge (CPC 1 or 2). According to multivariate analysis, predictors of good neurological outcome included arrest-to-first cardiopulmonary resuscitation attempt interval ≤5 min, ventricular fibrillation or ventricular tachycardia in the first monitored rhythm, absence of re-arrest before leaving the emergency department, arrest-to-return of spontaneous circulation interval ≤30 min and recovery of pupillary light reflex, which were identifiable in the emergency department. Based on this analysis, we developed a seven-point score (5-R score). If the score was ≥5, it predicted good neurological outcome with a sensitivity of 82.5% (95% confidence interval [CI], 67.2-92.7%) and specificity of 92.3% (95% CI, 74.9-99.1%). The negative predictive value of a score ≥4 was 100% (95% CI, 81.5-100%). Our prediction model was validated internally by a bootstrapping technique. CONCLUSIONS The prediction protocol using the 5-R score was associated with good neurological outcome of patients treated with TTM. Therefore, it could be helpful in clinical decision making on whether to initiate cooling.

Relationship between the hemoglobin level at hospital arrival and post-cardiac arrest neurologic outcome

BACKGROUND The hemoglobin (Hb) level is an essential determinant of oxygen delivery. The restoration of blood perfusion to vital organs and the capacity for oxygen delivery may be associated with ischemia and reperfusion injuries during cardiac arrest and after cardiac arrest. However, whether the Hb level is associated with neurologic outcome in post-cardiac arrest patients remains unclear. METHODS Emergency medical service information and clinical demographics were compiled for witnessed out-of-hospital cardiac arrest patients with coma after the restoration of spontaneous circulation. The study end point was defined as a favorable neurologic outcome at 28 days. We evaluated the relationship between the Hb level at the time of hospital arrival and the neurologic outcome using univariate analyses and a multivariate logistic regression analysis. RESULTS There were 137 witnessed cardiac arrest patients: 49 (35.7%) survived and 34 (24.8%) achieved a favorable neurologic outcome. Univariate analyses showed that the favorable outcome group was characterized as having a higher Hb level, a younger age, a higher percentage of male patients, and ventricular fibrillation as the initial cardiac rhythm. In a multivariate analysis adjusting for potential confounding factors, the Hb level at the time of hospital arrival (odds ratio, 1.26; 95% confidence interval, 1.00-1.58) was an independent predictor of a favorable neurologic outcome. CONCLUSION A higher Hb level at the time of hospital arrival was associated with a favorable short-term neurologic outcome among post-cardiac arrest patients with a presumed cardiac etiology.

Predictors for good cerebral performance among adult survivors of out-of-hospital cardiac arrest ☆

BACKGROUND Complete neurological recovery is of great importance to survivors of cardiac arrest. Few studies have explored predictors of good cerebral performance outcomes among these. METHODS We analyzed data from the SOS-KANTO study, a prospective, multi-center, observational study on patients who had out-of-hospital cardiac arrest. We included patients with Glasgow-Pittsburgh cerebral performance categories (GP-CPC) 1 (good cerebral performance) and 2 (moderate cerebral disability) at 30 days after cardiac arrest. RESULTS Among 122 eligible patients, 85 (70%) with GP-CPC 1 and 37 (30%) with GP-CPC 2 outcomes were analyzed. More patients with GP-CPC 1 outcome (27%) received conventional cardiopulmonary resuscitation (CPR) than those with GP-CPC 2 outcome (5%). Proportions for receiving cardiac-only resuscitation were not different between the two groups. Based on a multiple logistic-regression model constructed using age and significant variables from bivariate analyses, significant factors for GP-CPC 1 outcome included: conventional bystander CPR compared to no bystander resuscitation with an odds ratio of 5.7 (95% CI, 1.1-30.4); positive pupillary reflex at the time of ED arrival with an odds ratio of 13.7 (95% CI, 3.5-53.7); spontaneous respiration at ED arrival with an odds ratio of 5.98 (95% CI, 1.6-23.0); and cardiac cause of initial arrest with an odds ratio of 5.9 (95% CI, 1.4-25.0). CONCLUSIONS Survivors of out-of-hospital cardiac arrest with recovery to good cerebral performance were more likely to have cardiac cause of arrest and show positive pupillary reflex and spontaneous respiration at ED arrival.

Usefulness of initial blood cultures in patients admitted with pneumonia from an emergency department in Japan

Guidelines recommend obtaining blood cultures for all patients admitted with pneumonia. However, recent American studies have reported the low impact of these cultures on antibiotic therapy. Our aim was to investigate the incidence of bacteremia and change of therapy in admitted pneumonia patients from whom blood cultures were obtained in the emergency department (ED). A retrospective, observational, cohort study was conducted on consecutive patients (age ≥12 years) with pneumonia hospitalized through the ED between January 1 and December 31, 2006, in an urban teaching hospital in Japan. Data were collected on antibiotic sensitivities, empirical antibiotics, and changes of antibiotic management. Blood cultures were classified as positive, negative, or contaminant, based on previously established criteria. Out of 164 consecutive cases, blood cultures were positive in 6 patients (3.7%; 95% confidence interval [CI], 0.8%–6.6%), contaminated in 6 (3.7%), and negative in 152 (92.7%). Of the 6 bacteremic patients, 2 cases were likely to have been caused by concomitant diseases. Blood culture results altered therapy for 4 patients (2.4% of 164; 95% CI, 0.7%–6.1%), of whom 2 patients (1.2%; 95% CI, 0.1%–4.3%) had their coverage narrowed, 1 patient (0.6%; 95% CI, 0.0%–3.4%) had coverage broadened, and 1 patient had altered therapy before the drug sensitivities were reported. Considering cost and workload, the overall total annual cost was €758 631 (€107 = 1