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In general, an internal fire events probabilistic safety assessment (PSA) model is quantified by modifying the pre-existing internal event PSA model. Because many pieces of equipment or cables can be damaged by a fire, a single fire event can lead to multiple internal events PSA initiating events (IEs). Consequently, when the fire events PSA model is quantified, inappropriate minimal cut sets (MCSs), such as duplicate MCSs, may be generated. This paper shows that single quantification of a hypothetical single-top fire event PSA model may generate the following four types of inappropriate MCSs: duplicate MCSs, MCSs subsumed by other MCSs, nonsense MCSs, and MCSs with over-counted fire frequencies. Among the inappropriate MCSs, the nonsense MCSs should be addressed first because they can interfere with the right interpretation of the other MCSs and prevent the resolution of the issues related to the other inappropriate MCSs. In addition, we propose a resolution process for each of the issues caused by these inappropriate MCSs and suggest an overall procedure for resolving them. The results of this study will contribute to the understanding and resolution of the inappropriate MCSs that may appear in the quantification of fire events PSA models.

In this study, a numerical analysis was performed as part of an international joint research project to reproduce a real cable tray fire that occurred in the heater bay area of the turbine building of a nuclear power plant. A sensitivity analysis was performed on various input parameters to derive results consistent with the sprinkler activation time obtained from the fire event analysis. For all sensitive parameters, the normalized sprinkler activation time correlated well with the power function of the normalized sprinkler height. A correlation equation was developed to identify the sprinkler activation time at any location when determining the slope or fire growth rate under the conditions assuming a linear or t-squared heat release rate (HRR) time curve. Various cable fire growth assumptions were used to determine which assumption was better to provide the prediction coincident with the information given from the fire event analysis in terms of the sprinkler activation time and total energy generated from cables damaged by fire. In the comprehensive analysis of all the sensitive parameters, the standard deviation of the input parameters increased as the sprinkler height decreased. Within the range of the sensitivity parameter values given in this study, when considering all sprinkler heights, the standard deviation of the cable model change was the largest and that of the overhang position change was the smallest.

To determine the association between the induction rate and 6-month neurologic outcomes in out-of-hospital cardiac arrest (OHCA) survivors who underwent targeted temperature management (TTM). This retrospective observational study analyzed data prospectively collected from adult comatose OHCA survivors treated with TTM at the Chonnam National University Hospital in Gwangju, Korea, between October 2015 and December 2020. We measured the core body temperature (BT) through an esophageal probe and recorded it every 5 minutes throughout TTM. Induction time was defined as the elapsed time between the initiation of TTM and the achievement of target BT of 33°C. We calculated the induction rate as the change of BT divided by induction time. The primary outcome was a poor 6-month neurologic outcome, defined as cerebral performance category 3–5. Of the OHCA survivors, 218 patients were included, and 137 (62.8%) patients had a poor neurologic outcome. Patients with a poor neurologic outcome had lower BT at the initiation of TTM, shorter induction time, and higher induction rate than those with good neurologic outcomes. After adjusting for confounders, induction time (odds ratio [OR] 0.995; 95% confidence interval [CI], 0.992–0.999) and induction rate (OR 2.362; 95% CI, 1.178–4.734) were independently associated with poor neurologic outcome. BT at TTM initiation was not associated with a poor neurologic outcome. Induction rate was independently associated with a poor neurologic outcome in OHCA survivors who underwent TTM at 33°C.

We examined the association between variability in body temperature (BT) and water temperature (WT) during the maintenance period of targeted temperature management (TTM) and neurologic outcomes in out-of-hospital cardiac arrest (OHCA) survivors. Adult (≥18 years), comatose OHCA survivors who underwent TTM at 33°C between October 2015 and December 2019 were included. We collected data on BT and WT recorded every minute during the TTM maintenance period. Temperature variability was measured as the standard deviation of BT and WT during the 33°C maintenance period. The primary outcome was a poor neurologic outcome, defined as a cerebral performance category scale 3–5 at 6 months. Of the 154 included patients, 96 (62.3%) had poor outcomes. The BT variability in the poor outcome group was lower than that in the good outcome group (0.16°C [0.13–0.27°C] vs. 0.13°C [0.11–0.18°C]). In addition, the WT variability during the maintenance period in the poor outcome group was lower than that in the good outcome group (2.24°C [1.80–3.96°C] vs. 1.77°C [1.26–2.32°C]). In the multivariate analysis, WT variability (odds ratio 0.508; 95% confidence interval, 0.295–0.874; p= 0.014) was independently associated with poor neurologic outcome. BT variability and cooling beyond 33.0°C ± 1.0°C were not associated with poor neurologic outcomes. WT variability during the maintenance period was independently associated with neurologic outcomes in OHCA survivors who underwent TTM at 33°C. In addition, overcooling or undercooling during the maintenance period was not associated with neurologic outcomes.

We aimed to verify whether slow heart rate (HR) is associated with neurologic outcome and the factors that can contribute to the development of bradycardia in out-of-hospital cardiac arrest (OHCA) survivors who underwent targeted temperature management (TTM). We extracted the data of comatose adult OHCA survivors who underwent TTM between October 2015 and December 2018 from the prospective multicenter registry. Data on HR recorded every 6 hours within 72 hours after return of spontaneous circulation and calculated minimal, mean, and maximal HR and time to the lowest HR were obtained. HR <50 bpm was defined as bradycardia. The primary outcome was a 6-month neurologic outcome based on Pittsburgh-Glasgow Cerebral Performance Category Scale. Of the 814 included patients, 508 (62.4%) had poor neurologic outcome and 197 (24.2%) had bradycardia. Bradycardia (odds ratio [OR], 0.574; 95% confidence interval [CI], 0.362–0.192), minimal HR (OR, 1.023; 95% CI, 1.008–1.037), and mean HR (OR, 1.016; 95% CI, 1.002–1.030) were independently associated with poor neurologic outcome, but not maximal HR and time to the lowest HR. Preexisting arrhythmia (OR, 2.067; 95% CI, 1.037–4.118), renal disease (OR, 2.028; 95% CI, 1.153–3.567), cardiac etiology (OR, 1.526; 95% CI, 1.045–2.228), downtime (OR, 0.985; 95% CI, 0.974–0.996), and serum lactate levels (OR, 0.936; 95% CI, 0.900–0.974) were independently associated with bradycardia. Bradycardia and decreased mean and minimal HR were independently associated with good neurologic outcomes. Bradycardia was associated with preexisting arrhythmia, renal disease, cardiac etiology, shorter downtime, and lower serum lactate level.

The importance of performing Level 3 probabilistic safety assessments (PSA) along with a general interest in assessing multi-unit risk has been sharply increasing after the Fukushima Daiichi nuclear power plant (NPP) accident. However, relatively few studies on multi-unit Level 3 PSA have been performed to date, reflecting limited scenarios of multi-unit accidents with higher priority. The major difficulty to carry out a multi-unit Level 3 PSA lies in the exponentially increasing number of multi-unit accident combinations, as different source terms can be released from each NPP unit; indeed, building consequence models for the astronomical number of accident scenarios is simply impractical. In this study, a new approach has been developed that employs the look-up table method to cover every multi-unit accident scenario. Consequence results for each scenario can be found on the table, established with a practical amount of effort, and can be matched to the frequency of the scenario. Preliminary application to a six-unit NPP site was carried out, where it was found that the difference between full-coverage and cut-off cases could be considerably high and therefore influence the total risk. Additional studies should be performed to fine tune the details and overcome the limitations of the approach.

AbstractPurpose:The optimal timing for measurement of neutrophil gelatinase-associated lipocalin (NGAL) level to predict acute kidney injury (AKI) and prognosis in cardiac arrest (CA) survivors has not been elucidated. We aimed to compare the diagnostic and prognostic performance of NGAL levels after return of spontaneous circulation (ROSC) and at 48 h after CA.Methods:We included 231 adult cardiac arrest survivors who underwent targeted temperature management between May 2013 and December 2016. The primary outcome was stage 2 and 3 AKI (high stage AKI), and the secondary outcomes were in-hospital mortality and neurologic outcome. Sixty-one (26.4%) developed high stage AKI, 50 (21.6%) died, and 152 (65.8%) had a poor neurologic outcome.Results:NGAL level at 48 h (0.876; 95% confidence interval [CI], 0.826–0.916) had a higher area under receiver operating characteristic curve than NGAL level after ROSC (0.694; 95% CI, 0.631–0.753). Both NGAL levels were independently associated with high stage AKI. NGAL level at 48 h (1.001; 95% CI, 1.000–1.002) remained a significant predictor for in-hospital mortality, while neither of the NGAL levels were independently associated with neurologic outcome.Conclusions:NGAL at 48 h after CA seems to be a robust predictor for high stage AKI and in-hospital mortality.

Early diagnosis of acute kidney injury (AKI) after cardiac arrest (CA) is challenging. We aimed to identify the diagnostic and prognostic performance of neutrophil gelatinase-associated lipocalin (NGAL) for AKI and its clinical outcomes. A retrospective observational study, involving adult comatose CA survivors treated with therapeutic hypothermia between May 2013 and December 2016, was conducted. AKI was classified according to the guidelines of Kidney Disease Improving Global Outcomes. NGAL levels were measured after return of spontaneous circulation (ROSC). The primary outcome was development of AKI within 7 days after CA, and the secondary outcome was inhospital mortality. The study included 279 patients, of which 111 (39.8%) developed AKI and 61 (21.9%) died. Thirty-seven (33.3%) of patients in the AKI group had stage 3 AKI, and 45 (40.5%) patients received renal replacement therapy. The area under the curve of NGAL levels for diagnosing AKI was 0.725 (95% confidence interval [CI] 0.668–0.776), and NGAL levels were independently associated with the development of AKI (odds ratio [OR] 1.004; 95% CI 1.002–1.006). Nonsurvivors had significantly higher NGAL levels (221.0 ng/mL [154.0–355.5] vs. 148.5 ng/mL [97.0–232.9]; p< 0.001). The development of AKI was independently associated with mortality (OR 4.926; 95% CI 2.353–10.311); however, NGAL level was not associated with mortality (OR 1.000; 95% CI 0.999–1.001). Plasma NGAL level measured after ROSC can be an early predictor for the development of AKI after CA. The presence of AKI was associated with increased inhospital mortality.

Ginseng saponin has long been used as a traditional Asian medicine and is known to be effective in treating various kinds of pain. Ginsenoside Rf is one of the biologically active saponins found in ginseng. We evaluated ginsenoside Rf’s antinociceptive and anti-inflammatory effects, and its mechanism of action on adrenergic and serotonergic receptors, in an incisional pain model.

We examined the association between neuromuscular blockade (NMB) requirements and outcomes and lactate clearance in cardiac arrest survivors treated with targeted temperature management (TTM).

Published ahead of print March 17, 2017.

Published ahead of print October 29, 2015

We compared the quantitative clinical performances of the streamlined liner of the pharynx airway (SLIPA) and the ProSeal laryngeal mask airway (LMA ProSeal) regarding intensity of gastric distension in patients undergoing laparoscopic cholecystectomy.

Objectives This randomized, double-blind, placebo-controlled trial evaluated intraperitoneal (IP) lidocaine administration and intravenous (IV) lidocaine infusion for postoperative pain control after laparoscopic cholecystectomy (LC).Methods Patients who underwent LC were randomized to either group IV (intravenous lidocaine infusion), group IP (intraperitoneal lidocaine administration), or group C (control, IP and IV saline). Outcome measures were total postoperative pain severity (TPPS), total fentanyl consumption (TFC), frequency of administering patient-controlled analgesia (FPB), and a pain control satisfaction score (PCSS).Results Significantly reduced TPPS, TFC and FPB scores were observed in groups IP (n= 22) and IV (n= 26) compared with controls (n= 24). PCSS was higher in groups IP and IV than in controls. At 2 h postoperation, TPPS was significantly lower in group IP than group IV; at 0–2 h postoperation, FPB was lower in group IP than group IV.Conclusions The IP administration of lidocaine and IV lidocaine infusion significantly reduced postoperative pain and opioid consumption in LC patients, compared with control infusions. For convenience, IV lidocaine could be used for pain reduction following LC; IP administration places additional burden on the surgeon.

Objective To compare the efficacy of ramosetron, midazolam, and the combination of ramosetron and midazolam in the prevention of postoperative nausea and vomiting (PONV) in female patients undergoing thyroidectomy.Methods Patients were randomized to receive 0.3 mg ramosetron (Group R), 75 µg/kg midazolam (Group M) or 0.3 mg ramosetron combined with 75 µg/kg midazolam (Group RM) before the induction of anaesthesia. PONV, use of rescue antiemetics, pain severity and fentanyl consumption were assessed for 24 h after thyroidectomy.Results A total of 100 patients were enrolled; 94 patients completed the study. The severity of nausea was statistically significantly reduced at 0–2 h in Group RM compared with Groups R and M, and at 2–6 h in Group RM compared with Group M. The incidence of retching and vomiting was significantly lower at 0–2 h, 2–6 h, 6–12 h in Group RM than in Group M, and lower in Group R than Group M at 6–12 h. The requirement for rescue antiemetics was significantly lower at 0–2 h in group RM than in group M.Conclusion The combination therapy of ramosetron and midazolam provided superior antiemetic efficacy compared with midazolam single therapy, but did not show any significant additional benefits compared with ramosetron single therapy.

Introduction:We previously reported that pralidoxime potentiated the pressor effect of epinephrine and improved restoration of spontaneous circulation (ROSC) rate and short-term survival in pigs undergoing cardiopulmonary resuscitation (CPR). We sought to explore the optimal dose of pralidoxime to be used during CPR and to evaluate the involvement of ?-adrenoceptors in its pressor action.Methods:In the first substudy, 44 pigs randomly received one of three doses of pralidoxime (40, 80, or 120 mg/kg) or saline placebo during CPR. All animals were given epinephrine every 3 minutes. In the second substudy, 49 rats were divided into 7 groups. In the first 4 groups, the effects of 40 mg/kg pralidoxime on arterial pressure were determined after pretreatment with saline, guanethidine, phenoxybenzamine, or phentolamine. In the other 3 groups, the effects of 200 mg/kg pralidoxime were determined after pretreatment with saline, propranolol, or phentolamine.Results:In the first substudy, 40 mg/kg pralidoxime resulted in the highest coronary perfusion pressure (CPP) among the groups, while 120 mg/kg pralidoxime resulted in the lowest CPP (group effect P<0.001). Sustained ROSC was attained in 4 (36.4%), 11 (100%), 9 (81.8%), and 3 (27.3%) animals in the saline, 40 mg/kg, 80 mg/kg, and 120 mg/kg groups, respectively (P<0.001). In the second substudy, 40 mg/kg pralidoxime elicited a pressor response. Phenoxybenzamine completely inhibited the pressor response, but guanethidine and phentolamine did not. The pressor response of pralidoxime was even greater after pretreatment with guanethidine or phentolamine. Two-hundred mg/kg pralidoxime produced an initial vasodepressor response followed by a delayed pressor response. Phentolamine eliminated the initial vasodepressor response and reversed it into a pressor response.Conclusions:Forty mg/kg of pralidoxime administered with epinephrine led to a significantly higher ROSC rate by improving CPP in a pig model of cardiac arrest, whereas 120 mg/kg did not improve CPP or the ROSC rate. Our findings suggest that the pressor effect of pralidoxime is unrelated to ?-adrenoceptors and that its pressor effect is buffered by its vasodepressor action mediated by the inhibition of the sympathetic nervous system.

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