Emergency Operating Procedures Research Articles

Iodine source term assessment as result of iodine spiking and mass transfer phenomena during a SGTR transient using MELCOR 2.2 and CATHARE 2 codes

The European project denominated Reduction of Radiological Consequences of design basis and design extension Accidents (R2CA) was launched in September 2019, with a very broad participation: 11 countries, 17 participating organisations, including international organisations, utilities, regulators, technical support organisations, researchers and developers and was coordinated by IRSN. The main goal of the project was to assess the conservatisms in the radiological releases calculations in nuclear power plant (NPP) studies.The work here presented is focused on developing new calculation methodologies and updating computer code models to carry out more detailed assessments of source terms resulting from a steam generator tube rupture (SGTR) accident in the Design Extension conditions A (DEC-A) domain. For this purpose, participants in Work Package 2 (WP2) of R2CA developed and implemented simplified models in the Severe Accident (SA) and Thermal-Hydraulic (TH) codes that take into account iodine spiking and iodine transport phenomena within primary and secondary circuit. These methodologies will not only provide a better estimation of the radiological consequences, but should also serve to improve accident management procedures, innovative instrumentation development and early detection tools.The new approaches are tested in a SGTR + Steam Line Break Outside Containment scenario without significant fuel degradation in a three-loop Western 1000 MWe PWR. During the transient, operators are also assumed to implement emergency operating procedures (EOPs) in line with Westinghouse EOPs to limit the release of radioactivity and control the evolution of plant parameters.The calculations are performed by Tractebel and CIEMAT with the American SA tool MELCOR and Bel-V with the French TH code CATHARE.The results highlighted some limitations of implemented models in predicting iodine behaviour as well as small discrepancies in the TH evolution of the transient, both of which were analysed and discussed in detail.

Robust Diagnosis of Emergency Operating Procedures Under a Fire in Nuclear Power Plants

In this paper, a method of analyzing and processing information loss under a fire in nuclear power plants is proposed. By using this method, we can determine which information is valid. At the same time, this method provides a solution to management for invalid information. By screening the information used in emergency operating procedures (EOP) and analyzing its state in fire conditions, appropriate corrective measures (such as redundant information, redundant information, and forced value) are taken. It ensures that the information used by the operator is valid and reliable. It’s favorable for operators to identify the accident state of the plant and select appropriate accident strategies. Therefore, correct orientation and effective implementation of EOP in fire conditions are ensured.

The need for a course to complete urological education for consultant practice using a simulated ‘boot camp’ structure at the end of specialist training: A survey-based study

To obtain opinions from urology trainees and consultants regarding the need for, and structure of, a post-specialty training Urology Simulation Boot Camp (USBC) for consultant practice. A survey-based study was conducted, and 'Google Forms' were distributed electronically via social media. Urology specialist trainees (ST) in years 5-7 (ST5-ST7), post-certification of completion of training (CCT) fellows and ST3 boot camp faculty consultants in practice for ≤5 years and >5 years were included. One hundred and seven responses were received. 97.2% of responders thought a pre-consultant USBC was worthwhile; 55.1% selected the course duration to be 2 days. 47.7% felt that the USBC should be delivered post-exam in ST7. 91.6%, 43.9%, 73.8%, 87.9% and 74.8% considered that modules in emergency operative procedures, novel uro-technologies, delivering multidisciplinary team (MDT) meetings, non-clinical consultant roles and responsibilities, stress and burnout to be important, respectively. 62.6% and 31.8% felt that the course should be wholly or part-funded by Health Education England (HEE). A post-specialty training, pre-consultant, USBC delivered post-exam in ST7, is worthwhile and should include modules on emergency operative procedures, leading MDTs, non-clinical roles and responsibilities and managing stress and burnout in consultant careers. Ideally, it should be fully/part-funded by HEE.

Study on EOPs for PORV-Break LOCA in Generic PWR Simulator

After the Three Mile Island Unit 2 accident, regulatory bodies were concerned about the safety measures in design and operation corresponding to the operator’s decisions and procedures for handling such off-normal transients. Several recommendations were proposed to analyze transients and accidents, improve and revise emergency operating procedures (EOPs), and conduct functional training. In this work, procedural paths were systematically studied to identify the problems in the diagnosis associated with a pilot-operated relief valve (PORV)–break loss-of-coolant accident (LOCA) as well as to suggest new indications for improving the EOPs. Operational parameters during PORV-break LOCA and pipeline-break small-break LOCA were analyzed using a generic pressurized water reactor simulator to compare and justify the symptoms between these two events. It was found that suggesting further indications mainly in the reactor cooling system and containment symptoms may improve the diagnosis of a PORV-break LOCA from the pipeline-break small-break LOCA. This paper presents a practical approach to evaluating diagnostic procedures to better understand operator recovery actions corresponding to reactor system response in dealing with a PORV-break LOCA.

Application of external flood probabilistic safety assessment methodology to Prototype Fast Breeder Reactor

ABSTRACT This paper presents the methodology adopted, accident sequence analysis and salient results from the external flood probabilistic safety analysis exercise for Prototype Fast Breeder Reactor. The major steps performed are the probabilistic hazard estimation, fragility computation, system reliability modelling and risk quantification. The hazard analysis has been performed for rainfall, storm surge and tsunami as typically associated with a coastal site, from which correlation function relating flood level to the annual exceedance frequency is estimated. The fragility analysis of different safety systems is estimated by considering submergence mode of failure using step fragility functions. The secondary effects of flood such as debris impact, load falling and flood-induced sodium fires are not considered. The human reliability analysis of manual operations necessary for plant safety is done for the control room as well as onsite actions. The challenges encountered during the analysis, salient results and uncertainties involved are presented with inferences. Abbreviations: AHX: air heat exchanger; CDF: core damage frequency; EFPSA: external flood probabilistic safety assessment; EL: elevation levels; EOP: emergency operation procedure; ET: event tree; FT: fault tree; HRA: human reliability analysis; IE: initiating events; NPP: nuclear power plant; OGDHRS: operation grade decay heat removal system; PFBR: prototype fast breeder reactor; POT: peak over threshold; PSA: probabilistic safety assessment; PTHA: probabilistic tsunami hazard assessment; RY: reactor year; RCB: reactor containment building; RP: return period; SGDHRS: safety grade decay heat removal system; SSC: structures, systems and components

Rise in Percutaneous Vascular Procedures and Extracorporeal Membrane Oxygenation Is Associated With Increase in Emergent Vascular Operations.

Background: The workload of vascular surgeons is widely affected by the procedural activity of other departments within the same medical center. The purpose of this study was to evaluate the trend in emergent vascular surgery procedures over a 5year period in a tertiary referral hospital and categorize these procedures based on the nature of the operative procedure required. Methods: A single center, retrospective review of all emergent surgical operations performed at our tertiary referral hospital between the years 2017-2021. Data collected included types of emergent vascular surgery performed, in addition to procedures performed by the departments of interventional cardiology (IC), interventional radiology (IR), neurointerventional radiology (NIR) and extracorporeal membrane oxygenation (ECMO) at our institution. Results: During the study period were performed a total of 1783 operative procedures (mean 356 ± 26/year). Of those, 485 (27%) were emergent cases. We observed a gradual increase in emergent operative procedures performed from 2017 to 2021 (22% to 34% of all cases, increase of 56%, P<.01). A striking increase was seen with vascular repairs performed for iatrogenic vascular injuries secondary to arterial access complications (47% to 65% of all iatrogenic vascular injuries, increase of 38%). The increase correlated with an increase in activity seen in the departments of IC, IR/NIR and ECMO (15%, 31% and 300%, respectively). Conclusions: An increasing number of emergent surgical procedures performed by our vascular surgery department correlates with the increasing number of endovascular procedures performed by non- vascular services. As these procedures are expected to increase, together with the number of stroke units and ECMO units being created, medical centers must be aware that these may result in a significant increase in the workload of the vascular surgery department in order to deal with complications associated with these procedures.

Reversal of apixaban and rivaroxaban with andexanet alfa prior to invasive or surgical procedures.

Outcomes following andexanet alfa reversal of factor Xa inhibitors in patients requiring urgent or emergent invasive procedures are lacking. This study aimed to describe efficacy and safety outcomes following andexanet alfa administration within 24h of an invasive procedure. This single-center, observational, retrospective study included patients who received andexanet alfa within 24h of an invasive or surgical procedure. The primary outcome was hemostatic efficacy graded as excellent, good, or poor using similar definitions to the ANNEXA-4 criteria. Secondary outcomes included hospital discharge disposition, intensive care unit (ICU) and hospital length of stay, 30-day mortality, 30-day thromboischemic event rates, and serum coagulation assay changes pre- and postreversal. Forty-four patients met inclusion criteria; of these, 27 (62.8%) received apixaban and 16 (37.2%) were treated with rivaroxaban prior to admission. The indications for reversal were categorized as intracranial (n=20 [45.5%]) or extracranial (n=24 [54.5%]) sites. Majority of patients required emergent operative procedures (18 [40.9%]), followed by invasive device placement (10 [22.7%]) or arterial embolization (9 [20.5%]). Thirty-eight (86.4%) patients were able to be adequately graded for hemostatic efficacy. Overall, 30 (78.9%) patients achieved excellent or good hemostasis within 24h after periprocedural administration of andexanet alfa (19 [82.6%] apixaban vs. 11 [78.6%] rivaroxaban; 12 [80.0%] intracranial events vs. 18 [78.3%] extracranial events). Discharge disposition was most often to a short- or long-term care facilities (27 [61.4%]). Thirty-day mortality and thromboischemic complications occurred in 15 (34.1%) and 12 (27.3%) patients, respectively. Prothrombin time and antifactor Xa assay results were significantly decreased after andexanet alfa administration (p < 0.05) while thromboelastogram assay values (reaction time, kinetic time, and activated clotting time) showed nonsignificant changes pre- versus postreversal. Andexanet alfa may be used for urgent or emergent reversal of apixaban and rivaroxaban peri-procedurally with promising hemostatic outcomes. Further prospective, comparative clinical research is warranted.

Validation of EOPs/FRGs Procedures Using LOHS Scenario

Validation of EOPs (Emergency Operating Procedures) and FRGs (Function Restoration Guidelines) can be achieved either through plant full scope simulator or on desk top exercises. The desk top exercise is conducted when for the given scenario plant full scope simulator is not suitable. In either verification cases predefined scenario should be evaluated and possible branching foreseen. The scenario presented is LOHS, with bleed and feed procedure initiated. Best estimate light water reactor transient analysis code RELAP5/mod3.3 was used in calculation. Standardized detailed plant model was used. Operator actions were modelled from beginning of the scenario to its termination.

Accident Management under Extreme Events

Most nuclear power plants have extensive sets of Emergency Operating Procedures and Severe Accident Management Guidelines. These offer protection for a large series of events, both inside and outside the licensed design basis of the plant. For Extreme Events, which are characterised by a large destruction on-site and may include loss of command and control, damage to multiple units on-site, loss of communication both on-site and to off-site centres, staff members wounded or killed, such protection may not be enough. Examples of Extreme Events are air plane crash, site flooding, large earthquake plus possible tsunamis, etc. This paper describes what additional procedures, guidelines, hardware and organisational issues are needed to protect a site against such events. It is based on lessons learned from large destructive events in the past, such as the 9/11 attacks in the USA in 2001 and the tsunami at the Fukushima-Daiichi plants in 2011.

Assessment of plant response capability in the event of loss of electrical power and loss of ultimate heat sink

This paper presents a stress test method developed for Korean nuclear power plant and assessment results of plant response capability of OPR1000 in an effort to enhance the safety against extreme natural events exceeding the design basis of the plant. Multi-barrier accident coping strategy (MACST) guidelines have been developed to accomplish specific tasks in support of Emergency Operating Procedures (EOP) when the Extended Loss of AC Power (ELAP) and/or Loss of Ultimate Heat Sink (LUHS) is in progress as a consequence of beyond design basis natural events. Provisions to secure critical safety functions are discussed with cliff edge time evaluation at each step of plant response to ELAP and LUHS. It is concluded that the plant can maintain the safe shutdown state through the natural circulation cooldown by steam generator and the electric power and can obtain additional capability and redundancy with off-site equipment to provide coping capability for an indefinite period.

Association of ADHD With Congenital Conditions – Case Reviews in General Adult Clinic

AimsThe association of ADHD with mental health and medical conditions is commonly encountered in clinical practice. Interestingly there are patients with congenital conditions who present with features of ADHD and little is known about their association and neurological basis. There is no strong literature but anecdotal reports that indicate children with congenital heart disease are more likely to suffer from mental health conditions including ADHD. The clinic however is unable to analyze such hypothesis and instead decided to evaluate cases related to Neurofibromatosis (NF1), Arnold Chiari Malformation, Transposition of great arteries, Di George syndrome to understand the longitudinal history, symptom persistence and functional impact of ADHD.MethodsA.Index patient aged 45 years referred for possible association of ADHD and Neurofibromatosis with issues related to long-standing trouble with sleep and movement disorder.B.Index patient aged 41 years received a surgical repair for a Chiari malformation hoping it would improve the cognitive functioning but still suffers lot of symptoms that are consistent with clinical picture of ADHD.C.Index patient aged 19 years referred for ADHD assessment reported history of transposition of great arteries and VSD that warranted emergency operative procedure before age 3. The behavioural symptoms that were suspected as related to physical illness and frequent attendance to hospital however did not resolve and were noted to be in line with possible ADHD.D.Index patient aged 40 years admitted to general psychiatry following episode of psychosis and during examination presented history of Di George syndrome with brief input from Cardiology. It was apparent that patient struggled with poor understanding, lack of consistency, disorganization, distractibility, learning difficulties and the features suggested a pattern of Attention deficit disorder.ResultsFocused on 1.The qualitative analysis of developmental history, childhood rating scale, symptom comorbidity and functional impairment of such cases.2.It studied the family history of physical and mental illness including predisposition to ADHD or neurodevelopmental conditions.3.It also evaluated the treatment response to stimulant/non-stimulant therapy.ConclusionClinically there was no typical co-relation of increased mental illness or genetic predisposition for ADHD in the family history and qualitatively the presentation did not differ from other ADHD patients and the treatment response was not variable, however it still draws attention towards the need for regular screening of all nervous and cardiac origin congenital conditions for an early intervention.

C13 COMPARISON OF MINIMALLY INVASIVE VERSUS CONVENTIONAL THORACIC AORTIC OPERATIONS: EARLY AND MID–TERM RESULTS IN A SERIES OF 624 PATIENTS

Abstract Objective Despite minimally invasive techniques have gained wider clinical application in cardiac surgery, current evidence on mini thoracic aortic surgery is still limited. The aim of this study was to compare early and mid–term outcomes of patients undergoing proximal thoracic aortic interventions through mini–sternotomy (MS) versus full sternotomy (FS). Methods Data from 624 consecutive patients undergoing proximal aortic operations through MS (n = 214, 34.3%) and FS (n = 410, 65.7%) at 2 aortic centers, were analysed. Patients with prior cardiac operations and active endocarditis, and those who underwent emergency operation and combined procedures were excluded. Treatment selection bias was addressed by the use of propensity score matching (MS vs FS). After matching, 2 well–balanced groups of 202 patients each were created. Surgical procedures involved aortic valve replacement/repair and ascending aorta replacement in 190 patients (47%), aortic root replacement in 110 patients (27.2%) and isolated ascending aorta replacement in 104 patients (25.7%). Results The median cardiopulmonary bypass and cross clamp times were 88 and 68 minutes, respectively, with no difference between groups. Overall 30–day mortality was 0.7%, being 1% (n = 2) in patients underwent MS and 0.5% (n = 1) in those underwent FS (p = 0.6). No difference was found in the rates of stroke (MS n = 5, 2.5%; FS n = 5, 2.5%), dialysis (MS n = 1, 0.5%; FS n = 4,2%), bleeding (MS n = 7, 3.5%; FS n = 7, 3.5%), and blood transfusions (MS n = 67, 33.3%; FS n = 57, 28.4%) (Table 1). Patients receiving MS were associated with a lower incidence of respiratory insufficiency compared with those receiving FS (0% vs. 2.5%, p = 0.03). The median intensive care unit length of stay was 24 and 25 hours in MS and FS group, respectively (p = 0.3), and in–hospital stay was 7 days both in MS and FS group (p = 0.9). Three–year survival rate was 96.6% in patients receiving MS and 95.7% in those receiving FS (p = 0.9). Conclusions Our findings showed that mini proximal aortic operations can be performed successfully without compromising the proven efficacy and safety of conventional access. In selected patients, MS was associated with very low mortality and morbidity rates. Additionally, MS demonstrated superior clinical outcomes as regards respiratory adverse events, when compared with FS.

Concept of an intelligent operator support system for initial emergency responses in nuclear power plants

Nuclear power plant operators in the main control room are exposed to stressful conditions in emergency situations as immediate and appropriate mitigations are required. While emergency operating procedures (EOPs) provide operators with the appropriate tasks and diagnostic guidelines, EOPs have static properties that make it difficult to reflect the dynamic changes of the plant. Due to this static nature, operator workloads increase because unrelated information must be screened out and numerous displays must be checked to obtain the plant status. Generally, excessive workloads should be reduced because they can lead to human errors that may adversely affect nuclear power plant safety. This paper presents a framework for an operator support system that can substitute the initial responses of the EOPs, or in other words the immediate actions and diagnostic procedures, in the early stages of an emergency. The system assists operators in emergency operations as follows: performing the monitoring tasks in parallel, identifying current risk and latent risk causality, diagnosing the accident, and displaying all information intuitively with a master logic diagram. The risk causalities are analyzed with a functional modeling methodology called multilevel flow modeling. This system is expected to reduce workloads and the time for performing initial emergency response procedures.

Numerical assessment for entry condition of severe accident management guidelines in a Swedish nuclear power plant

The entry conditions of severe accident management guidelines (SAMGs) in pressurized water reactors (PWRs) rely on the indication of core exit temperature (CET). Yet, the setpoints for the CET may be different from plant to plant. Most Westinghouse PWR designs adopt the setpoint of CET at 650℃ as the entry condition of the SAMGs, since this setpoint is an effective indicator of core damage in a wide spectrum of accident sequences. Motivated by the interest in the verification & validation of SAMS after the Fukushima accidents, the present study is conducted numerically to verify the effectiveness of the CET setpoint for the transition from emergency operation procedures (EOPs) to SAMGs in a Swedish nuclear power plant. For this purpose, six representative severe accident sequences covering the main contributors to the core damage frequency (CDF) are analyzed using the MELCOR code. Moreover, different CET readings and alternative entry conditions are also investigated. The simulation results show that the average CET = 650 °C is the effective setpoint as the entry condition of SAMGs, i.e., given this setpoint the transition from EOPs to SAMGs will take place slightly before the occurrence of core degradation, which secures the intended mitigation of SAMGs while keeping EOPs active as long as possible. On the other hand, it is too conservative if the maximum CET = 650 °C is used as the setpoint of entry condition of SAMGs, i.e., it will result in an excessive realization of SAMGs over EOPs. The coolant temperature in the primary circuits, the water level in the RPV and the hydrogen concentration in the containment can also be applied as reference indications of core damage states in the accident management.

A comparative study on comprehension of informed consent before emergency and elective surgical operative procedures

introduction: A health-care beneficiary should comprehend different aspects of medical and surgical interventions before giving consent to perform those. There is no defined way to find out adequate patient comprehension as part of the decision-making procedure to give consent. This study was conducted to find out the disparity of comprehensiveness between emergency and elective surgical operative procedures both in terms of knowledge dissemination and knowledge comprehension. Materials and Methods: A cross-sectional comparative study was conducted at the General Surgery Department of Medical College, Kolkata, during September and October 2021. An interviewer-administered questionnaire was used on patients undergoing emergency and elective surgical procedures. The comprehension level of informed consent (IC) form was scored as 1, 2, and 3 and compared between two groups using an unpaired t-test and Mann–Whitney U-test. Result: Data collection was done from 39 patients for emergency operative procedures and 52 for elective surgical procedures. A composite comprehension score was calculated after adjusting for questions not asked while taking IC. The mean comprehension score for emergency procedures was 18.86 and for planned surgery, it was 20.14. Unpaired t-test showed significantly high mean comprehension for planned procedures than the emergency procedures (P = 0.007). Comprehension is significantly poorer in emergency conditions even after controlling for age and literacy denoting difficulty in decision-making in emergency scenarios. Conclusion: It is suggested that the procedure of consent taking should be more structured and interactive so that even in stressful conditions participant understand better about the procedures and take their own decision instead of relying blindly on doctors.

The Outcome of Emergency Surgery among Patients with Large Bowel Volvulus (LBV)

Introduction: volvulus is a twisting or axial rotation of a portion of bowel about its mesentery. Large Bowel Volvulus (LBV) accounts for (5%) of all organic large bowel obstructions and are most common between 50 and 60 years of ages .The reported incidence of the various forms of LBV, (59%) for sigmoid volvulus (SV), (39%) for caecal volvulus (CV) and (2%) for transverse colon volvulus. The diagnosis of acute LBV can be challenging because its clinical presentation has low specificity compared with other non-traumatic abdominal pain. Emergency surgery is the appropriate treatment for those who present with diffuse peritonitis, intestinal perforation or ischemic necrosis. Aim of the study: To review the comparison and benefits of emergency operative procedures in the treatment of patients with acute large bowel volvulus in the emergency setting. Place and Duration: Department of General Surgery at Azadi-teaching hospital in Kirkuk city from December 2008 to December 2013. Patients and Methods: Total 48 patients; 31 male (64.6%) and 17 female (35.4%) (95.8%) patients were over 55 years of age. were included in the study of which 41 (85.4%) diagnosed preoperatively with acute sigmoid volvulus on emergency laparotomy. The remaining 7 patients (14.6%) with caecal volvulus. The choice of surgical procedure depended on the; large bowel viability, time of presentation following onset of obstructive features, extent of proximal colonic dilatation, co morbid diseases and surgeon’s preference. For acute sigmoid volvulus; 11 patient (27.2%) patients underwent sigmoid resection with primary anastomosis (RPA), 18 patient (43.9%) underwent Hartmann’s procedure and 12 patients (29.3%) operated by sigmoid resection with Paul-Mikulicz. For caecal volvulus; Right hemicolectomy performed for three patients (42.9%), caecopexy in two (28.6%) and caecostomy in other two patients (28.6%). Results: Abdominal distension and constipation occurs in all patients (100%), while (95.8%) presented with abdominal pain and peritonitis in (79.2%) (41.5%) has a previous history of bowel decompression either by endoscopic instruments or deflation by rectal tube with a recurrence rate of (76.0%). Chronic medical illnesses are found in most of the patients. LBV is presented in two forms sigmoid (85.4%) of cases, the rest (14.6%) with caecal volvulus. (33.4%) of cases presented with gangrenous colon while bowel perforation (fecal peritonitis) in (4.2%). The operative procedures ;- one stage Resection with Primary Anastomosis in (26.8%) of patients , two stage operative procedures resection of the volvulus sigmoid with (Hartmann and Paul-Mikulicz done in (73.2%), in caecal volvulus right hemicolectomy (with ileo-transverse Anastomosis done for (42.9%), caecopexy (28.6%) and Caecostomy for 2 patients(28.6%) patients. Postoperative complications; Wound infection in (31.3%) of cases. Anastomotic leak (12.5%). Total mortality occurs in 10 cases (20.8%). Conclusion: In acute LBV emergency surgery is indicated, Hartmann’s procedure is the procedure of choice. The presence of cardiac, renal, or respiratory diseases has a significant impact on the complications, morbidity and mortality of patients undergoing surgery for large bowel volvulus.

Effects of Automation for Emergency Operating Procedures on Human Performance in a Nuclear Power Plant.

The digitization of the control systems in the main control room of a nuclear power plant has changed the operators’ role in coping with accidents and has thus brought about new human factor problems. This article focuses on the procedures that are used for guiding the emergency operating procedures in a nuclear power plant, and experimentally investigates the effects of the digitization of procedures on operators’ mental workload and situation awareness. In these experiments, the procedures at three different levels of automation, namely, paper-based procedures (PBPs), electronic procedures (EPs), and computer-based procedures (CBPs), are used as the independent variables. According to the experimental results, using these procedures at a high level of automation enables the operator to exhibit favorable operational performance with a decreased mental workload; however, the operator’s situation awareness (SA) is decreased. The research results presented here can provide a reference level for optimally setting the level of automation of the emergency operating procedures in a nuclear power plant and provide support for the optimization of a corresponding HRA (Human Reliability Analysis) model.

Development of Fuel Product Barrier Monitoring System Based on State Functions in State-Oriented Emergency Operating Procedure

For pressurized water reactor nuclear power plants, in order to prevent the release of radioactive substances into environment, fission product barriers (FPBs) are constructed based on the concept of defense-in-depth, including fuel clad, reactor coolant system (RCS), and containment; the status of these FPBs is then acting as an important dimension to decision-making of emergency action levels (EALs). For CPR1000 nuclear power plants, state functions defined in state-oriented emergency operating procedure (SOP) are used to characterize postaccident physical conditions; their degradation substantially represents the challenges on fundamental safety functions and then on the integrity of FPBs in like manner, so degradation of these state functions is referred to as determining initial conditions of each FPB, by which the link between SOP and EALs is established. Then, an intelligent FPB monitoring system (FPBMS) aiming to automatically monitor states of FPBs is developed, verified, and validated. The pioneering work, by building bridges between state functions and initial conditions of FPBs and then computerizing them innovatively, proves that dynamical monitoring of states of FPBs during accident evolvement and real-time indication of loss or potential loss of FPBs can be achieved, which is most helpful in decision-making of EALs.

Guidelines for maxillofacial surgeon concerning emergency operative procedures in COVID-19 outbreak

The COVID-19 pandemic is now a global problem that has significantly impacted the safe practice of Maxillofacial Surgery. It is important to compile information and experiences that have been gained worldwide and define a set of guidelines for best practice for staff performing these procedures and for patients undergoing maxillofacial surgery procedures. As such, these recommendations should be treated as 'expert opinion' and are based mostly on personal communication, guidelines put forth by various national and international societies, and peer-reviewed data when possible. Surgical procedures involving the nasal-oral-endotracheal mucosal region are high risk due to aerosolization of the virus, which is known to be in high concentration in these areas when compared to swabs from the lower respiratory tract1. Further, it appears that if viral particles become aerosolized, they stay in the air for at least 3 h, if not longer. Based on experience in Wuhan, China, and Northern Italy, N95 masks were not enough to control this spread of the disease and it was not until powered air-purifying respirators were introduced that transmission of the virus was controlled among medical personnel. The current paper focuses on setting basic guidelines for dental operating surgeons in taking up an emergency operative procedure. © 2021 Wolters Kluwer Medknow Publications. All rights reserved.

Microscopic inflammation in ileocecal specimen does not correspond to a higher anastomotic leakage rate after ileocecal resection in Crohn’s disease

BackgroundPatients with Crohn’s disease suffer from a higher rate of anastomotic leakages after ileocecal resection than patients without Crohn’s disease. Our hypothesis was that microscopic inflammation at the resection margins of ileocecal resections in Crohn’s disease increases the rate of anastomotic leakages.Patients and methodsIn a retrospective cohort study, 130 patients with Crohn’s disease that underwent ileocecal resection between 2015 and 2019, were analyzed. Anastomotic leakage was the primary outcome parameter. Inflammation at the resection margin was characterized as “inflammation at proximal resection margin”, “inflammation at distal resection margin” or “inflammation at both ends”.Results46 patients (35.4%) showed microscopic inflammation at the resection margins. 17 patients (13.1%) developed anastomotic leakage. No difference in the rate of anastomotic leakages was found for proximally affected resection margins (no anastomotic leakage vs. anastomotic leakage: 20.3 vs. 35.3%, p = 0.17), distally affected resection margins (2.7 vs. 5.9%, p = 0.47) or inflammation at both ends (9.7 vs. 11.8%, p = 0.80). No effect on the anastomotic leakage rate was found for preoperative hemoglobin concentration (no anastomotic leakage vs. anastomotic leakage: 12.3 vs. 13.5 g/dl, p = 0.26), perioperative immunosuppressive medication (62.8 vs. 52.9%, p = 0.30), BMI (21.8 vs. 22.4 m2/kg, p = 0.82), emergency operation (21.2 vs. 11.8%, p = 0.29), laparoscopic vs. open procedure (p = 0.58), diverting ileostomy (31.9 vs. 57.1%, p = 0.35) or the level of surgical training (staff surgeon: 80.5 vs. 76.5%, p = 0.45).ConclusionMicroscopic inflammation at the resection margins after ileocecal resection in Crohn’s disease is common. Histologically inflamed resection margins do not appear to affect the rate of anastomotic leakages. Our data suggest that there is no need for extensive resections or frozen section to achieve microscopically inflammation-free resection margins.