Lower Proportion of Fatal Arrhythmia in Sudden Cardiac Arrest Among Patients With Severe Mental Illness Than Nonpsychiatric Patients.

BACKGROUND: Sudden unexpected deaths occur more frequently among patients with severe mental illness (SMI), but direct evidence on the causes is still scarce. OBJECTIVE: The objective of this study is to investigate initial rhythms and characteristics of out-of-hospital cardiac arrest among patients with SMI. METHODS: We conducted a systematic chart review of adult patients who suffered from out-of-hospital cardiac arrest and transferred to Tokyo Metropolitan Bokutoh Hospital in Japan between January 2011 and December 2017. The initial rhythms, clinical characteristics, and outcomes were compared between patients with schizophrenia or mood disorders (i.e., SMI) and nonpsychiatric control patients. Values of interest were compared using Fisher's exact test or Mann-Whitney U-test, as appropriate. Multiple regression analysis was also conducted to investigate the effect of SMI on the initial rhythms. RESULTS: A total of 2631 patients were included in this study. Of these, 157 patients had SMI. Fatal arrhythmias (i.e., ventricular fibrillation and ventricular tachycardia) were less frequently noted as the initial rhythms among patients with SMI than among controls (5.7% vs. 18.8%, adjusted odds ratio = 0.27, 95% confidence interval = 0.13-0.55, P < 0.001). Patients with SMI were significantly younger (median [range], 58 years [22-85] vs. 72 years [18-108], P < 0.001) and less frequently had comorbid physical illnesses than controls (the proportion of patients without comorbidities; 58.6% vs. 37.1%, P < 0.001). Survival and neurological function at discharge were not different between the 2 groups. CONCLUSION: Fatal arrhythmia may account for a relatively small portion in excess of sudden death among patients with SMI. Furthermore, appropriate medical checkups for the patients with SMI at earlier ages would be important to prevent sudden cardiac death.

Etiology of out-of-hospital cardiac arrest in psychiatric patients: Chart review.

AIM: Although sudden cardiac deaths are more common in psychiatric patients than the general population, data on their causes are very limited. The aim of this study was to investigate initial rhythms and causes of out-of-hospital cardiac arrest (OHCA) in patients with psychiatric disorders. METHODS: We conducted a systematic chart review of patients resuscitated after OHCA and hospitalized in the Tertiary Emergency Medical Center of Tokyo Metropolitan Bokutoh Hospital in Japan between January 2010 and December 2017. The initial rhythms and causes of OHCA were compared between psychiatric patients and non-psychiatric patients. Parameters of interest were compared using chi-squared test, Fisher's exact test, or the Mann-Whitney U-test, as appropriate. RESULTS: A total of 49 psychiatric and 600 non-psychiatric patients were eligible for this study. Fatal but shockable arrhythmias (i.e. ventricular fibrillation and ventricular tachycardia) were less frequently observed as initial rhythms in patients with psychiatric disorders than the others (22.4% vs 49.7%, P < 0.001). Cardiac origin was less common as the cause of OHCA (26.5% vs 58.5%, P < 0.01), while airway obstruction and pulmonary embolism were more frequent in psychiatric versus non-psychiatric patients (24.5% vs 6.5%, P < 0.01; and 12.2% vs 1.5%, P < 0.01, respectively). The results were similar when psychiatric patients were compared with sex- and age-matched controls selected from the non-psychiatric patient group. CONCLUSION: Although fatal arrhythmias may be less common, non-cardiac causes such as pulmonary embolism and airway obstruction need to be treated with high clinical suspicion in an event of sudden cardiac arrest in psychiatric patients.

Purpura fulminans with Lemierre's syndrome caused by Gemella bergeri and Eikenella corrodens: a case report.

BACKGROUND: Gemella bergeri is one of the nine species of the genus Gemella and is relatively difficult to identify. We herein describe the first case of septic shock due to a Gemella bergeri coinfection with Eikenella corrodens. CASE PRESENTATION: A 44-year-old Asian man with a medical history of IgG4-related ophthalmic disease who was prescribed corticosteroids (prednisolone) presented to our hospital with dyspnea. On arrival, he was in shock, and a purpuric eruption was noted on both legs. Contrast enhanced computed tomography showed fluid retention at the right maxillary sinus, left lung ground glass opacity, and bilateral lung irregular opacities without cavitation. Owing to suspected septic shock, fluid resuscitation and a high dose of vasopressors were started. In addition, meropenem, clindamycin, and vancomycin were administered. Repeat computed tomography confirmed left internal jugular and vertebral vein thrombosis. Following this, the patient was diagnosed with Lemierre's syndrome. Furthermore, he went into shock again on day 6 of hospitalization. Additional soft tissue infections were suspected; therefore, bilateral below the knee amputations were performed for source control. Cultures of the exudates from skin lesions and histopathological samples did not identify any pathogens, and histopathological findings showed arterial thrombosis; therefore it was concluded that the second time shock was associated with purpura fulminans. Following this, his general status improved. He was transferred to another hospital for rehabilitation. The blood culture isolates were identified as Gemella bergeri and Eikenella corrodens. Gemella bergeri was identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry and confirmed by 16S rRNA gene sequencing later. The primary focus of the infection was thought to be in the right maxillary sinus, because the resolution of the fluid retention was confirmed by repeat computed tomography. CONCLUSIONS: Gemella bergeri can be the causative pathogen of septic shock. If this pathogen cannot be identified manually or through commercial phenotypic methods, 16S rRNA gene sequencing should be considered.

Categorization of post-cardiac arrest patients according to the pattern of amplitude-integrated electroencephalography after return of spontaneous circulation.

BACKGROUND: Continuous electroencephalography (cEEG), interpreted by an experienced neurologist, has been reported to be useful in predicting neurological outcome in adult patients post cardiac arrest. Amplitude-integrated electroencephalography (aEEG) is a type of quantitative EEG and is easily interpreted by a non-neurologist. A few studies have shown the effectiveness of aEEG in prognostication among adult patients post cardiac arrest. In this study, we hypothesized that the pattern of aEEG after return of spontaneous circulation (ROSC) could successfully categorize patients post cardiac arrest according to their expected neurological outcome. METHODS: We assessed the comatose survivors of out-of-hospital cardiac arrest who received targeted temperature management with midazolam-based sedation and were monitored with aEEG at our tertiary emergency care center from January 2013 to June 2017. We categorized the patients into categories 1 (C1) to 4 (C4). C1 included patients who regained continuous normal voltage (CNV) within 12 h post ROSC, C2 included those who recovered CNV 12-36 h post ROSC, C3 included those who did not recover CNV before 36 h post ROSC, and C4 included those who had burst suppression at any time post ROSC. We evaluated the outcomes of neurological function for each category at hospital discharge. A good outcome was defined as a cerebral performance category of 1 or 2. RESULTS: A total of 61 patients were assessed (median age, 60 years), among whom 42 (70%) had an initial shockable rhythm, and 52 (85%) had cardiac etiology. Of all 61 patients, 40 (66%) survived to hospital discharge and 27 (44%) had a good neurological outcome. Of 20 patients in C1, 19 (95%) had a good outcome, while the percentage dropped to 57% among C2 patients. No patients in C3 or C4 had a good outcome. Three patients could not be classified into any category. CONCLUSIONS: The pattern of aEEG during the early post-cardiac-arrest period can successfully categorize patients according to their neurological prognoses and could be used as a potential guide to customize post-cardiac-arrest care for each patient.

Unidirectional motion of a camphor disk on water forced by interactions between surface camphor concentration and dynamically changing boundaries.

We study the motion of a camphor disk on the water surface in a system with flexible boundaries. The boundaries can be dynamically modified by non-uniform surface tension resulting from the nonhomogeneous surface concentration of the camphor molecules dissipated by the disk. We investigate the geometry of the boundaries that forces unidirectional motion of the disk. The studied system can be regarded as a signal diode if the presence or absence of a camphor disk at a specific point is interpreted as the binary TRUE and FALSE variables. The diode can be incorporated into more complex devices, like a ring that imposes unidirectional rotation of camphor disks.

Effect of ultrasonography and fluoroscopic guidance on the incidence of complications of cannulation in extracorporeal cardiopulmonary resuscitation in out-of-hospital cardiac arrest: a retrospective observational study.

BACKGROUND: It remains unclear which cannulation method is best in cases of extracorporeal cardiopulmonary resuscitation (ECPR) for out-of-hospital cardiac arrest. We assessed the effect of ultrasound- and fluoroscopy-guided percutaneous cannulation on complication incidence, compared with that using only ultrasound guidance. METHODS: This single-center retrospective observational study was conducted between February 2011 and December 2015. In the comparison group, cannulation was performed percutaneously using only ultrasound guidance. In the exposure group, cannulation was performed percutaneously using fluoroscopy and ultrasound guidance. The primary outcome assessed was whether complications were associated with cannulation. The secondary outcome assessed was the duration from hospital arrival to extracorporeal circulation start. In addition to univariate analysis, multivariate logistic-regression analysis for cannulation complications was performed to adjust for several presumed confounders. RESULTS: Of the patients who underwent ECPR, 73 were eligible; the comparison group included 50 cases and the exposure group included 23 cases. Univariate analysis showed that the complication incidence of the exposure group was significantly lower than that of the comparison group (8.7 vs. 36.0%, p = 0.022). Duration from hospital arrival to extracorporeal circulation start was almost the same in both groups (median, 17.0 min vs. 17.0 min, p = 0.92). After multivariate logistic regression analysis, cannulation using fluoroscopy and ultrasound was independently associated with a lower complication incidence (adjusted odds ratio, 0.14; p = 0.024). CONCLUSIONS: Ultrasound- and fluoroscopy-guided cannulation may reduce the complication incidence of cannulation without delaying extracorporeal circulation start.

Spontaneous Coronary Artery Dissection With Concomitant Coronary Vasospasm.

We herein describe a case of acute myocardial infarction due to spontaneous coronary artery dissection complicated by vasospastic angina. Given the need for different clinical management strategies of these cardiac manifestations, clinicians should consider the possibility of concomitant vasospasm in cases of spontaneous coronary artery dissection.

Increased collateral flow by rescue femorofemoral bypass dissolved residual thrombus in implanted iliofemoral artery stents: a case report.

BACKGROUND: Failed aortofemoral and femoropopliteal bypass grafts in the lower extremity artery usually result in acute limb ischemia. Endovascular treatment and surgical revascularization have been reported for limb salvage. CASE PRESENTATION: A 72-year-old Japanese man was admitted with acute limb ischemia due to failed aortofemoral and femoropopliteal bypass grafts. Endovascular treatment with balloon angioplasty, thrombectomy, and stent implantation in the long chronic total occlusion from the right common iliac artery to the superficial femoral artery did not result in efficient flow due to thrombus transfer from a failed aortofemoral bypass graft. However, a rescue femorofemoral bypass (the left femoral to the right deep femoral artery) improved his symptoms, and implanted in-stent flow was gradually recovered. Lower extremity angiography performed 5 months later confirmed the patency of the iliofemoral in-stent flow. However, the femorofemoral bypass graft was unfortunately occluded due to the progression of left external iliac artery stenosis. The patency of the iliofemoral in-stent flow was confirmed at 1 year by ultrasonography. CONCLUSIONS: Improvement of the deep femoral artery flow plays an important role in the treatment of acute limb ischemia due to failed aortofemoral and femoropopliteal bypass grafts. Thus, increased collateral circulation to the periphery through the deep femoral artery dissolved the remaining in-stent thrombus in the iliofemoral artery.

Effect of a product on spontaneous droplet motion driven by a chemical reaction of surfactant.

We focus on the self-propelled motion of an oil droplet within an aqueous phase or an aqueous droplet within an oil phase, which originates from an interfacial chemical reaction of surfactant. The droplet motion has been explained by mathematical models, which require the assumption that the chemical reaction increases the interfacial tension. However, several experimental reports have demonstrated self-propelled motion with the chemical reaction decreasing the interfacial tension. Our motivation is to construct an improved mathematical model, which explains these experimental observations. In this process, we consider the concentrations of the reactant and product on the interface and of the reactant in the bulk. Our numerical calculations indicate that the droplet potentially moves in the cases of both an increase and a decrease in the interfacial tension. In addition, the reaction rate and size dependencies of the droplet speed observed in experiments were well reproduced using our model. These results indicate the potential of our model as a universal one for droplet motion.

A Successful Treatment Strategy for Paradoxical Cerebral Embolism Accompanied by Entrapped Thrombus in Patent Foramen Ovale.

A 73-year-old man was transferred to our hospital with dyspnea and left hemiplegia. The diagnosis of pulmonary embolism, entrapped thrombus in patent foramen ovale (PFO), and internal carotid artery occlusion was made by imaging studies. We decided to perform endovascular treatment without the administration of tissue plasminogen activator (tPA) for cerebral embolism because of concern about further embolism caused by fragmented thrombi. After endovascular treatment, he successfully underwent surgical embolectomy for entrapped thrombus in PFO. Endovascular treatment without tPA administration and subsequent surgical embolectomy seems to be a viable treatment strategy for patients with occlusion of the large cerebral artery accompanied by entrapped thrombus in PFO.

Landiolol, a new ultra-short-acting beta1-blocker, reduces anaesthetic requirement during sevoflurane/N(2)O/fentanyl anaesthesia in surgical patients.

BACKGROUND AND OBJECTIVE: It is known that esmolol, a short-acting beta1-blocker, reduces anaesthetic requirement. In this study, we evaluated whether a low dose of landiolol, a new ultra-short-acting beta1-blocker, can reduce the sevoflurane requirement. METHODS: Twenty-five patients undergoing hip surgery were randomly divided into two groups. Group A (n = 13) received landiolol (bolus injection of 0.031 mg.kg(-1) and continuous infusion at a rate of 0.01 mg.kg(-1).min(-1)). Group B (n = 12) received physiological saline. Landiolol and physiological saline were started before the induction of anaesthesia and continued until the end of anaesthesia. Anaesthesia was maintained with sevoflurane, 60% N(2)O and fentanyl. Sevoflurane concentration was controlled to keep the bispectral index at approximately 50. The end-tidal sevoflurane concentration and haemodynamics were measured during anaesthesia. RESULTS: The average end-tidal sevoflurane concentration in group A was significantly lower than that in group B (1.2 +/- 0.30 vs. 1.8 +/- 0.3%, P < 0.01). Maximum values of systolic arterial pressure showed no difference between the groups, whereas the maximum value of heart rate in group A was significantly less than that in group B (61 +/- 10 vs. 76 +/- 14 beats min(-1), P < 0.05). CONCLUSION: The results suggest that a low dose of landiolol significantly reduces the intraoperative sevoflurane requirement during sevoflurane/N(2)O/fentanyl anaesthesia in patients undergoing hip surgery.

Postoperative analgesia with minidose intrathecal morphine for bipolar hip prosthesis in extremely elderly patients.

PURPOSE: It is known that an optimal dose of intrathecal morphine for analgesia after total hip arthroplasty in older patients is 0.1 mg. On the other hand, minidose intrathecal morphine (0.05 mg) is useful for analgesia after the transurethral resection of the prostate in elderly patients. We evaluated the postoperative analgesic effect of minidose intrathecal morphine after bipolar hip prosthesis in seniors (age 85 years or more) undergoing spinal anesthesia. METHODS: Twenty seniors undergoing bipolar hip prosthesis under spinal anesthesia were randomly allocated to one of two groups. Group A (n = 10) received intrathecal injection of 0.5% isobaric bupivacaine, 2.8 ml, and group B (n = 10) received intrathecal injection of 0.5% isobaric bupivacaine, 2.8 ml, plus morphine, 0.05 mg. Pain, nausea, and itching were evaluated using a numerical rating scale, ranging from 0 to 10, at 0, 4, 8, 12, and 24 h after the operation. RESULTS: The values on the numerical rating scale for pain in group B were significantly lower than those in group A at 4, 8, and 12 h after the operation. There were no significant differences between the groups in the values on the numerical rating scale for nausea or itching throughout the time course of the study. No patient in either group showed hypoxemia or respiratory depression throughout the time course. CONCLUSION: The results show that minidose intrathecal morphine provides a good analgesic effect without side effects, and it would be an effective and safe procedure for bipolar hip prosthesis in seniors.

Successful support by veno-arterial extracorporeal membrane oxygenation for severe septic shock caused by Aeromonas hydrophila.

BACKGROUND: Septic shock is a subset of sepsis accompanied by profound circulatory and cellular metabolism abnormalities. Although veno-arterial extracorporeal membrane oxygenation (VA-ECMO) can provide temporary cardiac support to improve organ perfusion, hemodynamic support by VA-ECMO for adult patients with septic shock is still controversial. CASE PRESENTATION: A 67-year-old man was transferred to our hospital with generalized weakness. He suffered septic shock refractory to vasopressors and inotropes, and his cardiac function deteriorated rapidly. Because of concern for sudden cardiac arrest, he was placed on VA-ECMO 9 h after his arrival. Blood culture was positive for Aeromonas hydrophila. He was weaned off VA-ECMO on day 7 and was discharged without any sequelae on day 30. CONCLUSION: Veno-arterial extracorporeal membrane oxygenation is a viable treatment option for adult patients with refractory septic shock accompanied by cardiac dysfunction. Further research is warranted to identify the candidates for support by VA-ECMO in a timely fashion.

Treatment of a patient with acute aortic dissection using extracorporeal cardiopulmonary resuscitation after an out-of-hospital cardiac arrest: a case report.

Case: Circulatory support using veno-arterial extracorporeal membrane oxygenation for aortic disease is conventionally contraindicated. In this case, a 66-year-old man experienced cardiopulmonary arrest caused by acute aortic dissection. When exercising in the gym, he experienced chest discomfort, so the staff immediately called an ambulance. While in the ambulance, he experienced cardiopulmonary arrest. His initial electrocardiogram showed ventricular fibrillation. At the emergency department, we immediately performed extracorporeal cardiopulmonary resuscitation. We suspected acute coronary syndrome, so coronary angiography was carried out. Enlargement of ascending aorta was noted. Whole-body enhanced computed tomography was subsequently performed, leading to a final diagnosis of acute aortic dissection. Outcome: Emergency ascending aorta prosthesis implantation was performed. The patient received intensive care and was discharged on day 49 of hospitalization. His cerebral performance category score was 4 at discharge. Conclusion: This case suggests that veno-arterial extracorporeal membrane oxygenation may be used for patients with aortic dissection presenting with cardiac arrest.

Broad distribution spectrum from Gaussian to power law appears in stochastic variations in RNA-seq data.

Gene expression levels exhibit stochastic variations among genetically identical organisms under the same environmental conditions. In many recent transcriptome analyses based on RNA sequencing (RNA-seq), variations in gene expression levels among replicates were assumed to follow a negative binomial distribution, although the physiological basis of this assumption remains unclear. In this study, RNA-seq data were obtained from Arabidopsis thaliana under eight conditions (21-27 replicates), and the characteristics of gene-dependent empirical probability density function (ePDF) profiles of gene expression levels were analyzed. For A. thaliana and Saccharomyces cerevisiae, various types of ePDF of gene expression levels were obtained that were classified as Gaussian, power law-like containing a long tail, or intermediate. These ePDF profiles were well fitted with a Gauss-power mixing distribution function derived from a simple model of a stochastic transcriptional network containing a feedback loop. The fitting function suggested that gene expression levels with long-tailed ePDFs would be strongly influenced by feedback regulation. Furthermore, the features of gene expression levels are correlated with their functions, with the levels of essential genes tending to follow a Gaussian-like ePDF while those of genes encoding nucleic acid-binding proteins and transcription factors exhibit long-tailed ePDF.

Conventional cardiopulmonary resuscitation-induced refractory cardiac arrest due to latent left ventricular outflow tract obstruction due to a sigmoid septum: a case report.

BACKGROUND: Patients with left ventricular outflow tract obstruction who do not exhibit a dynamic pressure gradient at rest, experience pressure gradient increases of ≥ 30 mmHg only during specific situations; this is called latent left ventricular outflow tract obstruction. It is provoked by increased cardiac contraction and preload and afterload depletion. There are a few reports of patients with it developing cardiac arrest. We present a case of latent left ventricular outflow tract obstruction in which the patient with a sigmoid septum experienced refractory pulseless electrical activity due to conventional advanced cardiac life support. CASE PRESENTATION: A 73-year-old Asian woman on escitalopram and lorazepam was transported to our hospital for chest and back pain with altered consciousness. On arrival, she was in shock and developed pulseless electrical activity. After initiation of conventional cardiopulmonary resuscitation according to adult advanced cardiovascular life support guidelines, she could not regain spontaneous circulation. She was ultimately resuscitated via venoarterial extracorporeal membrane oxygenation initiation. The only abnormal laboratory result at admission was anemia. Her hemodynamic status stabilized after red blood cell transfusion, and venoarterial extracorporeal membrane oxygenation was subsequently terminated. Transthoracic echocardiography showed a sigmoid septum; dobutamine-infused Doppler echocardiography revealed a significant outflow gradient, and continuous monitoring showed Brockenbrough-Braunwald sign, which confirmed a diagnosis of latent left ventricular outflow tract obstruction due to a sigmoid septum. As a result, carvedilol and verapamil were initiated. A follow-up dobutamine-infused Doppler echocardiography showed a reduction of outflow gradient, and she was discharged without any sequelae. Latent left ventricular outflow tract obstruction worsened due to increasing cardiac contraction and the depletion of preload and afterload. Depleted preload occurred due to dehydration and anemia, whereas depleted afterload occurred due to the prescribed drugs, which subsequently caused pulseless electrical activity. Moreover, ß-stimulation from the adrenaline probably enhanced the hypercontractile state and caused refractory pulseless electrical activity in our case. CONCLUSIONS: Patients with latent left ventricular outflow tract obstruction can progress to cardiogenic shock and pulseless electrical activity due to increased cardiac contraction and depletion of preload and afterload. We should consider the patient's underlying conditions that induced pulseless electrical activity.

Microalbuminuria is a prognostic predictor in aneurysmal subarachnoid hemorrhage.

OBJECTIVE: To determine the prevalence and the prognostic significance of microalbuminuria in patients after aneurysmal subarachnoid hemorrhage (SAH). DESIGN: Prospective and observational clinical study. SETTING: Multidisciplinary intensive care unit. PATIENTS: Fifty-one consecutive patients who underwent aneurysm clipping or endovascular surgery after SAH; 8 patients who underwent surgical clipping for unruptured intracerebral aneurysm served as control. INTERVENTION: None. MEASUREMENTS AND RESULTS: General clinical and neurological data were recorded on admission. Urine was collected preoperatively and daily for up to 7 days postoperatively for measuring the urinary microalbumin/creatinine ratio. The Glasgow Coma Scale (GCS) score was also determined on admission and daily for up to 7 days after operation. Neurological outcome was assessed using the Glasgow Outcome Scale (GOS) at 3 months after stroke. The prevalence rates of microalbuminuria were 74.5% in SAH and 37.5% in the control. Among the 51 patients, 25 had unfavorable neurological outcome (GOS 1-3). The areas under the receiver operator characteristic curves showed that the highest urinary microalbumin/creatinine ratio and the lowest GCS score during the first 8 days were the significant predictors of unfavorable neurological outcome. The threshold value, sensitivity, specificity, and likelihood ratio for the highest urinary microalbumin/creatinine ratio were 200 mg/g, 60% [95% confidence interval (CI) 41-79], 96% (95% CI 88-100), and 15.6 (95% CI 9.1-26.7), respectively. CONCLUSIONS: This study confirms a high prevalence of microalbuminuria in the SAH patients, and it suggests that the highest urinary microalbumin/creatinine ratio > 200 mg/g during the first 8 days is a significant predictor of unfavorable neurological outcome.

[Case of fulminant type 1 diabetes mellitus complicated with acute renal failure treated with continuous hemodiafiltration].

A 50-year-old male patient developed diabetic ketoacidosis with shock, acute renal failure treated with continuous hemodiafiltration (CHDF) and high serum CPK levels. Because of acute onset of ketoacidosis accompanied with an elevation of serum amylase, and negative findings of antibodies associated with autoimmune type 1 diabetes mellitus, he was diagnosed as a fulminant type 1 diabetes mellitus, which is a newly established subtype of type 1 diabetes mellitus. We managed to keep blood glucose concentrations within 150-200 mg x dl(-1) with continuous insulin intravenous infusion, and controlled circulation with dopamine. Since the blood glucose on admission was extremely high (1,870 mg x dl(-1)), the severe dehydration due to extreme hyperglycemia might have caused acute renal failure (ARF) and rhabdomyolysis. He was treated with CHDF for them. In a case of fulminant type 1 diabetes mellitus complicated with ARF early intensive support including CHDF for ARF must be considered in addition to intensive insulin therapy.

Splash detail due to a single grain incident on a granular bed.

Using the discrete element method, we study the splash processes induced by the impact of a grain on a randomly packed bed. Good correspondence is obtained between our numerical results and the findings of previous experiments for the movement of ejected grains. Furthermore, the distributions of the ejection angle and ejection speed for individual grains vary depending on the relative timing at which the grains are ejected after the initial impact. Obvious differences are observed between the distributions of grains ejected during the earlier and later splash periods: the form of the vertical ejection-speed distribution varies from a power-law form to a lognormal form with time; this difference may determine grain trajectory after ejection.

Neurological outcomes and duration from cardiac arrest to the initiation of extracorporeal membrane oxygenation in patients with out-of-hospital cardiac arrest: a retrospective study.

BACKGROUND: We investigated the relationship between neurological outcomes and duration from cardiac arrest (CA) to the initiation of extracorporeal membrane oxygenation (ECMO) (CA-to-ECMO) in patients with out-of-hospital cardiac arrest (OHCA) treated with extracorporeal cardiopulmonary resuscitation (ECPR) and determined the ideal time at which ECPR should be performed. METHODS: During the time period in which this study was conducted, 3451 patients experienced OHCA. This study finally included 79 patients aged 18 years or older whose OHCA had been witnessed and who underwent ECPR in the emergency room between January 2011 and December 2015. Our primary endpoint was survival to hospital discharge with good neurological outcomes (a cerebral performance category of 1 or 2). RESULTS: Of the 79 patients included, 11 had good neurological outcomes. The median duration from CA-to-ECMO was significantly shorter in the good neurological outcome group (33 min, interquartile range [IQR], 27-50 vs. 46 min, IQR, 42-56: p = 0.03). After controlling for potential confounders, we found that the adjusted odds ratio of CA-to-ECMO time for a good neurological outcome was 0.92 (95% confidence interval: 0.87-0.98, p = 0.007). The area under the receiver operating characteristic curve of CA-to-ECMO for predicting a good neurological outcome was 0.71, and the optimal CA-to-ECMO cutoff time was 40 min. The dynamic probability of survival with good neurological outcomes based on CA-to-ECMO time showed that the survival rate with good neurological outcome decreased abruptly from over 30% to approximately 15% when the CA-to-ECMO time exceeded 40 min. DISCUSSION: In this study, CA-to-ECMO time was significantly shorter among patients with good neurological outcomes, and significantly associated with good neurological outcomes at hospital discharge. In addition, the probability of survival with good neurological outcome decreased when the CA-to-ECMO time exceeded 40 minutes. The indication for ECPR for patients with OHCA should include several factors. However, the duration of CPR before the initiation of ECMO is a key factor and an independent factor for good neurological outcomes in patients with OHCA treated with ECPR. Therefore, the upper limit of CA-to-ECMO time should be inevitably included in the indication for ECPR for patients with OHCA. In the present study, there was a large difference in the rate of survival to hospital discharge with good neurological outcome between the patients with a CA-to-ECMO time within 40 minutes and those whose time was over 40 minutes. Based on the present study, the time limit of the duration of CPR before the initiation of ECMO might be around 40 minutes. We should consider ECPR in patients with OHCA if they are relatively young, have a witness and no terminal disease, and the initiation of ECMO is presumed to be within this time period. CONCLUSIONS: The duration from CA-to-ECMO was significantly associated with good neurological outcomes. The indication for patients with OHCA should include a criterion for the ideal time to initiate ECPR.