Review of literature on Postoperative Pulmonary Complications

Review of literature on Postoperative Pulmonary Complications According to Polit and Hungler (1999) the task of reviewing research literature involves the task of reviewing research literature involves the identification, selection, critical analysis and written description of existing information on the topic. Related literature which was reviewed is discussed under the following headings. Studies related to overview of the postoperative pulmonary complications. Studies related to chest physiotherapy and incentive spirometry. Studies related to overview of postoperative pulmonary complications Soledad Chumillas (1998) posited that pulmonary function is commonly altered after surgery, particularly in patients who have had chest or upper abdominal surgery. The physiological changes observed are directly related to anaesthesia (general or regional) and to the type of incision and surgical technique employed, and are reflected by decreases in total pulmonary capacity and pulmonary volumes and by a parallel decrease in Pa02. Yoder (2009) said that thoracic and upper abdominal surgery is associated with a reduction in vital capacity by 50% and in functional residual capacity by 30%. Diaphragmatic dysfunction, postoperative pain, and splinting make these changes. After upper abdominal surgery, patients shift to a breathing pattern with which ribcage excursions and abdominal expiratory muscle activities increase. Postoperative patients maintain adequate minute volume, but the tidal volume is very low and the respiratory rate increases. These abnormal breathing patterns, along with the residual effects of anesthesia and postoperative analgesics, inhibit cough, impair mucociliary clearance, and contribute to the risk of postoperative pulmonary complications. David Warner (2005) described that many factors responsible for PPCs are related to disruption of the normal activity of the respiratory muscles, disruption that begins with the induction of anaesthesia and that may continue into the postoperative period. The effects of anaesthesia can persist into the postoperative period, though via different mechanisms, as the effects of surgical trauma come into play. These are most pronounced following thoracic and abdominal surgery, and arise from at least three mechanisms. First, functional disruption of respiratory muscles by incisions, even after surgical repair, may impair their effectiveness. Postoperative pain may cause voluntary limitation of respiratory function. Finally, stimulation of the viscera, such as provided by mechanical traction on the gallbladder or esophageal dilation, markedly decreases phrenic motor neurone output and changes the activation of other respiratory muscles, in general acting to minimize diaphragmatic descent. Other factors that may contribute to PPCs include: 1) Reflex stimulation during surgery, and release of inflammatory mediators by drug administration, increasing airway resistance and limiting expiratory gas flow from the lung; if severe this can produce hyperinflation with risk of barotrauma and gas exchange abnormalities. 2) Impairment of normal mucociliary transport by anaesthetic gasses and endotracheal intubation which may delay clearance of pathogens and promote retained secretions 3)Impairment of lung inflammatory cells function by prolonged anaesthesia and surgery, which could increase susceptibility to postoperative infections 4) Impaired upper airway reflexes postoperatively, with may increase the risk of aspiration, and 5) Incomplete reversal of neuromuscular blockade. Rochelle Wynne and Mari Botti (2004) postulated that the pathogenesis of postoperative pulmonary dysfunction is associated with anomalies in gas exchange, alterations in lung mechanics, or both. Abnormalities in gas exchange are evidenced by a widening of the alveolar-arterial oxygen gradient, increased micro vascular permeability in the lung, increased pulmonary vascular resistance, increased pulmonary shunt fraction, and intrapulmonary aggregation of leukocytes and platelets. Variations in the mechanical properties of the lung lead to reductions in vital capacity, functional residual capacity, and static and dynamic lung compliance. Woerlee (2009) listed certain performance criteria for the respiratory system of a surgical patient. They are: The lungs must have sufficient oxygen to oxygenate the blood. The pulmonary circulation must eliminate carbon dioxide from the body to prevent carbon dioxide accumulation. The client must be able to generate a productive cough, otherwise mucus accumulation will occur resulting in atelectasis and/or lung infection or pneumonia. The client must be able to significantly increase their respiratory minute volume to compensate for factors such as increased postoperative metabolic rate, elevated body temperature, possible infections, pneumonia, etc. Poor performance in significantly raising and sustaining an elevated respiratory minute volume results in exhaustion and respiratory failure. Postoperative pulmonary complications account for a substantial portion of the risks related to surgery and anaesthesia and are a source of postoperative morbidity, mortality and longer hospital stays. The current basis for our understanding of the nature of Postoperative pulmonary complications is weak; only a small number of high quality studies are available, a uniform definition has not emerged, and studies have focused on specific patients and kinds of surgeries. Current evidence suggests that risk factors for Postoperative pulmonary complications are related to the patients health status and the particular anaesthetic and surgical procedures chosen. Age, pre-existing respiratory and cardiac diseases, the use of general anaesthesia and overall surgical insult are the most significant factors associated with complications. Election of anaesthetic technique, postoperative analgesia and chest physiotherapy seem to be the preventive measures that are best supported by evidence. (J.C anet, V.Mazo, 2010) J.C.Hall ., et.al (1991)evaluated the relationship between postoperative pulmonary complications and various putative risk factors in a prospective longitudinal study of 1000 patients undergoing abdominal surgery. Transient subclinical events were studied by defining postoperative pulmonary complications as positive clinical findings in combination with either positive sputum microbiology, unexplained pyrexia, or positive chest roentgenographic findings. The overall incidence of postoperative pulmonary complications was 23.2%(232/1000). These findings supplies clinicians and clinical nurse with a simple means of identifying patients who are at high risk of postoperative pulmonary complications after abdominal surgery. Postoperative pulmonary complications contribute significantly to the overall perioperative morbidity and mortality. Pulmonary complications occur significantly more often in patients undergoing elective surgery of the thorax and abdomen. These include atelectasis, infections including bronchitis and pneumonia, respiratory failure and bronchospasm. Sharma (2000). The study findings of Brooks-Brunn (1995) revealed that atelectasis and infectious complications account for the majority of reported pulmonary complications. Risk factors were thought to exaggerate pulmonary function deterioration, which occurred both during and after surgical procedures. 18 risk factors were reviewed regarding their Pathophysiology, impact on preoperative, intra operative and postoperative pulmonary function in this study. Identification of risk factor and prediction of postoperative pulmonary complications are important. Preoperative assessment and identification of patients at risk for postoperative pulmonary complications can guide our respiratory care to prevent or minimize these complications. Postoperative pulmonary complications were investigated in a total of 41 paediatric recipients who underwent orthotopic liver transplantation. Atelectasis was seen in 40 cases (98%) of the 41 recipients, and occurred in the left lower lobe in 28 cases (68%), and in the right upper lobe in 25 cases (61%). Radiographic pulmonary edema occurred on 23 occasions in 18 recipients (45%). Five recipients experienced two episodes of pulmonary edema during their ICU stay. Pleural effusions were observed in 21 cases (52%), of which 18 had right sided effusion and 3 had bilateral effusions. Pneumothorax occurred in 3 cases. Pyothorax, hemothorax, bronchial asthma and subglottic granulation occurred in one case each. The present study demonstrated that postoperative pulmonary complications are frequently observed in paediatric recipients undergoing orthotopic liver transplantation. (Toshihide et.al.,1994). Kanat et al., (2007) studied the risk factors for postoperative pulmonary complications in upper abdominal surgery. They concluded that pulmonary complications are the most frequent causes of postoperative morbidity and mortality in upper abdominal surgery. A prospective study on 60 consecutive patients was conducted who underwent elective upper abdominal surgery in general surgical unit. Each patients preoperative pulmonary status was assessed by an experienced chest physician using clinical examination, chest radiographs, spirometry, blood analysis, anaesthetical risks, surgical indications, operation time, incision type, duration of nasogastric catheter and mobilization time. Complications were observed in 35 patients (58.3%). The most complications were pneumonia followed by pneumonitis, atelectasis, bronchitis, pulmonary emboli and acute respiratory failure. They recommend a detailed pulmonary examinations and spirometry in patients who will undergo upper abdominal surgery by ch est physicians to identify the patients at high risk for postoperative pulmonary complications, to manage respiratory problems of the patients before surgery and also to help surgeons to take early measures in such patients before a most likely postoperative pulmonary complications occurrence. Serojo et al., (2007) in a prospective cohort study, studied risk factors for pulmonary complications after emergency abdominal surgery. Pertinent data were collected through interview and chart review and their association with the occurrence of postoperative pulmonary complications were analyzed. 286 consecutive children were included and 75 (28.2%) developed postoperative pulmonary complications. Pulmonary complications are frequent among children undergoing abdominal surgery and lead to increased length of hospital stay and death rate. Kilpadi ,et al., (1999) in a prospective study of respiratory complications, conducted a study for a period of six months with total samples of 584 patients, who underwent elective or emergency surgery. He found that 81 of them had 13.9% of respiratory complications, 68% had pneumonia and others included pleural effusion, empyema and exacerbation of asthma. Felardo et al., (2002) investigated the postoperative pulmonary complications after upper abdominal surgery. Two hundred and eighty three patients were followed from pre to postoperative period. A protocol including a questionnaire, physical examination, thoracic radiogram and spirometry was used during preoperative period. Sixty nine (24.4%) patients had pulmonary complications in 87 events registered. Pneumonia was the most frequent event 34% (30/87) followed by atelectasis 24% (21/87), broncho constriction 17% (15/87), acute respiratory failure 13% (11/87), prolonged mechanical ventilation 9% (8/87) and bronchial infection 2% (2/87). Pulmonary complications occurs more frequently than cardiac complications. The complication rates for upper abdominal and thoracic surgery are the highest. A better understanding of the risk factors associated with postoperative pulmonary complications is essential to develop strategies for reducing these complications. In any individual patient the benefit from a surgical procedure should be weighed against the risks it imposes. When possible, stabilization of respiratory status is advisable before surgery. (Muhammed Aslam, Syed Hussain, 2005). Decline in pulmonary function after major abdominal surgery is thought to be identified in daily assessment by observation of breathing and pain intensity. Measurement of pulmonary function is usually not included in the assessment of the patient in postoperative period. The aim of this study was to investigate the relationship between clinical observation of breathing and decline in pulmonary function and pain. Eighty nine patients admitted for elective major, mild and upper abdominal surgery, participated in the study. Clinical observation of breathing covered the following parameters like abdominal expansion, side expansion, high thoracic expansion, paradoxical breathing, symmetry of thorax expansion, ability to huff and signs of mucus retention. Pain intensity was assessed at rest and during breathing exercises and during coughing using a visual analogue scale. Peak expiratory flow rate were performed on the preoperative day and for seven postoperative day. A poor correlation is found between clinical observation of breathing and pulmonary function after abdominal surgery. (Johannes vandeleor et al ., 2003). Fung et al., (2010) compared postoperative respiratory complications in obese and nonobese children following surgery for sleep-disordered breathing. All obese children who had undergone adenotonsillectomy for sleep-disordered breathing from 2002 to 2007 were compared with age- and gender-matched controls. Length of hospital stay and the incidence, severity, and location of respiratory complications were compared.  Forty-nine obese children were identified (20:29, female: male). Overall, 37 obese children (75.5%) and 13 controls (26.5%) incurred complications (P = 0.000). Ten obese patients and two controls incurred major events (P = 0.012); 36 obese children had minor complications versus 12 controls (P = 0.000). Obese children had significantly more upper airway obstruction (19 vs. 4, P = 0.0003), particularly during the immediate postoperative period. The mean hospital stay was significantly longer for the obese group (18 vs. 8 hours, P = 0.000, mean difference of 10 hours). He concluded that Obesity in children significantly increases the risk of respiratory complications following surgery for sleep-disordered breathing. Sixty patients were studied to determine the incidence of postoperative pulmonary complications and the value of preoperative spirometry in producing pulmonary complications after upper abdominal surgery. On the day before the operation and for 15 days after the operation, each patients respiratory status was assessed by clinical examinations, chest x-ray, spirometry and blood gas analysis. A chest physician and surgeon monitored patients for pulmonary complications independently. In this study postoperative pulmonary complications developed in 21(35%) patients (pneumonia in 10 patient, bronchitis in 9 patients, atelectasis in 1 patient, pulmonary embolism in 1 patient) of 31 patients with abnormal preoperative spirometry, 14 patients showed normal preoperative spirometry, 7 patients showed complications. It was concluded that postoperative pulmonary complications was still a serious cause of postoperative morbidity. (Kocabas et al.,1996). Study conducted by Ephgrave et al., (1993) revealed that postoperative pneumonia was a major complication that had been linked to micro aspiration of pathogens originating in the gastrointestinal tract. 140 patients who had undergone major surgeries were selected. Postoperative pneumonia is present in 26 (18.6%) of 140 patients. Postoperative pneumonia is a morbid postoperative complications associated with presence of gastric bacteria during operation and transmission of gastric bacteria to the pulmonary tree after surgery. Studies related to chest physiotherapy and incentive spirometry Chest physiotherapy is an important therapy in the treatment of respiratory illness. It is very important to carry out this procedure in children for the purpose of loosening secretions from the lungs. Morran, et al., (1993) has done a randomized controlled trial on physiotherapy for postoperative pulmonary complications. A sample size of 102 patients undergoing cholecystectomy were assigned to control group and study group. The patients in the control group did not receive chest physiotherapy, while patients in the study group received chest physiotherapy. The study proved that without chest physiotherapy 21 patients developed atelectasis and 19 patients developed chest infections whereas with chest physiotherapy 15 patients developed atelectasis and 7 developed chest infection and 40 patients developed no complication. The author concluded that routine prophylactic chest physiotherapy significantly decreased frequency of chest infection (p

Health safety and the environment report feyzin

The aim of this project is to describe the incident which took place in Feyzin, south of France, on Tuesday January 4th 1966. This project describes the history of the refinery, a description of the LPG manufacture processes, the cause of the accident, details of the accident, inquires and safety measures, conclusion and personal recommendations. A focus group for the project was the first approach on research to explore people's ideas and attitudes to the accident. There were several weekly group meetings excluding the weekly tutor meetings putting forward ideas discussing whether the accident could have been for seen and reasonable measures were in place. Each member of the group was assigned a particular area in which they were to collect information. The required information was gathered from various highly reliable sources such as a HSE investigation. History And Background Information. Feyzin is situated in the suburbs of Lyon in the southern part of France. The France national petroleum was located in Feyzin. The refinery at Feyzin had started operating in 1964. The main objective of this processing plant was to produce 1.7 million tonnes a year of LPG (liquefied petroleum gas). LPG is a by-product of the distillation of oil from crude oil. When the distillate is put under pressure its physical state changes into a liquid. It is in this form that LPG is transported around in cylinder tanks. Because of the relatively short life span of the site prior to the incident, the cascade of events may be relatively short and that major issues will have risen during both the design and construction of the site. We can assume now that the plant was between its 1st and 2nd year of operation. LPG is a combination of Propane (Pressure 12 Bar, 37 degrees Celsius) and Butane (Pressure 2.6 Bar, 37 degrees Celsius).The LPG is used as an alternative to petrol.[Aarding India Pvt Ltd, 2007] The LPG is important because it is widely used as a fuel for vehicles and as cooking gas since its manufacture. They are also used as Industrial fuel and heating oils which are vital for many process plants. [Herman F. Mark et al, 1982] LPG is employed for starting up solid-fuel and oil-fired boilers supplying turbo generators. It is potential stand by for gas turbine generating equipment run on interruptible gas supplies. Its use for peak-load turbines will be economical to some circumstances. [BP trading ltd, 1972] Cascade events The causes of the deadly incident which took place at Feyzin There were quite a few reasons reported which were believed to be the causes of the explosion. Cause of the leakage: Three operators opened 2-inch valves which were mounted in series at a bottom of a 1200m3 propane spherical tank. The valves did not close at a LPG tank which contained 1200kl propane, which led to the leakage of LPG gas, a major cause of the explosion. For LPG that is Propane gas, when the pressure is lowered to atmospheric one the temp drops to -40. At this temperature moisture in air is frozen, but also the moisture reacts with LPG forming a solid hydrate. So either the downstream valve did not close tightly because of hydrate formation or the valve handle was stuck by the frozen moisture. This accident was believed to be caused as the upstream valve was not opened fully and the pressure at the outlet of the first valve was near the atmospheric pressure, the pressure difference cooled. It is very wrong to operate the valve system like that. Therefore, the cause of the explosion is either the operator's human mistake or a mistake on the management not to inform the proper execution of the operation. Cause of the ignition: The leaked LPG is presumed to be travelled for a distance and spread along the ground. A car driving down a local road might have sparked the ignition which is maybe due to the driver's cigarette or the car engine's hot temperature. Note that the layout of the plant was restricted to the landscape; a highway was constructed just 50m away from the large LPG tanks which exploded during the incident. Moreover there was no dike around the tanks which exploded, when large amount of LPG leaked, the vapour flew along the ground to the highway. The main cause of the ignition is that there was no dike around the LPG tanks and the distance regulation insufficient. Secondly, the legs of the spherical tank were made of iron which weren't fire proof. Thirdly, is that the distance between the adjacent tanks was really close, The actual distance between the centre of the tanks was just 27m according to the facility information provided. This proves that the adjacent tanks were affected so easily from the explosion of the first tank. Event A BLEVE (Boiling Liquid Expanding Vapour Explosion) was the disaster that occurred at Feyzin. It is an explosion phenomenon caused by the rapid phase change (vaporization) of a liquid. At 6:30am three operators started the water draining operation of a tank. Two valves were opened in series on the bottom of the sphere. When the operation was nearly complete, the upper valve was closed and then cracked open again. No flow came out of the cracked valve, so it was opened further. The blockage, assumed to be ice or hydrate, cleared and propane gushed out. The operator was unable to close the upper valve and by the time he attempted to close the lower valve this was also frozen open. The LPG leak started here because that valve was not closed completely. After a few minutes the operators were covered in propane vapour. The leaking LPG spread in the direction of the highway, with partially vaporizing. The alarm rang in the control room at this time. At around 7:05am; the alarm rang and it is not clear if it rang throughout the Feyzin districts or just the Feyzin refinery. The first fire truck of the factory turned out immediately. After this the traffic on the highway next to the refinery was stopped. The fire brigade of Lyon arrived at 7:20. Just after 7:30am, a car came and stopped on the local road where the traffic had not been stopped. The explosion apparently occurred after the car had stopped. The fire increased in power, spread along the leaking LPG, and the tank was overcome with flames immediately. By 8:40am the first tank at the refinery exploded by the BLEVE. The second and third spherical tanks exploded five minutes later. Two more spherical tanks and many oil tanks burned continuously. The next day in the morning the fire was extinguished. As a result of this it was reported that 18-81 persons died and about 80-130 persons got injured included members of the fire fighting team. The physical damage included five LPG tanks, many atmospheric tanks containing crude oil and jet fuel, and so on. The Feyzin Refinery suffered extensive damage. The LPG tank farm where the sphere was located consisted of four 1200 m3 propane and four 2000 m3 butane spheres. The fire brigade arrived on site, but were not experienced in dealing in refinery fires, and it appears they did not attempt to cool the burning sphere. They concentrated their hoses on cooling the remaining spheres. About 90 minutes after the initial leakage, the sphere ruptured, killing the men nearby. A wave of liquid propane flowed over the compound wall and fragments of the ruptured sphere cut through the legs of the next sphere which toppled over. The relief valve on this tank began to emit liquid. What is believed to have happened on the day of the accident is: the upstream valve was not opened fully and the pressure at the outlet of the first valve was near atmospheric pressure, hence the upstream valve was cooled by the pressure difference. It is absolutely prohibited to operate valves in such manner. Therefore, the cause of the accident is either the operator's human error or a mistake on management side in not explaining the proper operation protocols. Another contributing factor to the accident is that the operator did not close the downstream valve. There is insufficient information available to why this valve was not closed. It is assumed that either ice is generated in the downstream valve like in the upstream valve or a rapid large LPG leak occurred, the operator may have panicked when they could not close the upstream valve and therefore may have not remembered to close the downstream valve. Basically they had to decrease the downstream valve opening when the LPG began to appear in the drain water. Then the valve had to be closed at the end of the drain work. Either they forgot to carry out this procedure or they could not close the second valve because it had also become stuck by freezing. 1) Valve A is closed 2) Valve A cracks open 3) Valve A becomes blocked due to freezing 4) No flow through valve A 5) Valve A is opened 6) Ice block in valve A becomes dislodged 7) Valve A freezes in open position 8) Unable to close valve A 9) Valve B freezes in open position 10) Unable to close valve B 11) Pressure sphere fluid leaks through open valves 12) Fluid level in pressure vessel drops decreasing internal pressure 13) Liquid propane begins to boil due to pressure drop 14) Pressure in vessel increases due to liberated gaseous propane 15) Fluid flow through valves A and B increases due to increase in pressure 16) Vessel pressure continues to increase 17) Pressure vessel ruptures 18) Gaseous propane escapes vessel Recommendations and summary * Geographical location and details * History of Feyzin, including cascade events * Incident timeline and possible description of why it happened * Geographical effects of the incident * Results of the inquiry and official recommendations * Personal recommendations not covered by the enquiry Geographical location and details In order to get a better understanding of the scale of the Feyzin incident, it is important to note the location of the site in regards to the local area in which the site was and still is positioned. This will give an indication to understanding the safety procedures that were in place at the time of the incident and how emergency procedures were carried out at the time. It has proven very difficult to obtain a clear picture of the geographical location either prior to or following the incident of the site and so it will be assumed that the current location of the site, circa 2009, is the same location at the time of the incident. Close examination of this map may also indicate the most likely positioning of the epicentre of the primary detonation. Fig 1. Map of Feyzin Birds eye view 2009 Sandwiched between the A7 Expressway to the east of the site and the ‘Le grand large' river to the west, on close examination, it appears that some form of storage containers are located just west of the top E15 label in the image. This may lead us to assume that the storage containers were in the same location prior to the 1966 incident. On a broader scale it may also be seen that this location is approximately 10 km south of the major city of Lyon. Research suggests that at the time of the incident, the site lacked any serious on site systems in case of a major crisis, relying more on the local public services to resolve anything arising such as the incident in question. Again on close inspection of the map, it can be seen that the site is placed within a fairly urbanised area. Again we must assume a similar layout at the time of the incident though populations will be quite different from the 1966 incident and the 2009 map. This will assist in understanding the cause of the incident overall and the scale of the overall effect in this area. Apart from just repeating the timeline for the actual incident, it is important to try and understand why the incident took place, outside of the events leading up to and after what happened. The sequence of events surrounding the cracking and freezing of the ‘upper' valve, and the subsequent rupture of the pressure vessel need to be understood, in order to get a better understanding of how such a crises may be avoided in the future. These events may only have taken place over a very short time frame but they are essential to understanding the crises. One of the critical questions that should be asked is why following the closure of valve A and the subsequent cracking and freezing up of the valve, was the valve then opened. Thus allowing the ice block to become dislodged and the rest of the above sequence to take place. The reasons for this particular action, in opening valve A may be described in four ways. The first possibility may be a simple case of curiosity. The valve was closed and froze, and so to check that the valve was still properly operational was then opened. The second possibility is that the correct procedure for such an event was not properly followed. That the correct procedure would have stated that in such an event, the valve should have been kept closed and the problem be properly reported to maintenance. Therefore the valve operator was responsible for the incident that took place. The third possibility is that no official procedure or training had been formulated for such an event. Therefore panic may have ensued resulting in the opening of the valve as a panic decision which can therefore be described as human error. The fourth possibility is that the official procedure was followed properly and that the procedure was critically floored. So the issue of a misunderstanding of such an event or even ignorance of such was present at the time of this crisis. The third possibility seems likely case based on the immediate actions of the individual as he made the decision not to use a phone close to the pressure tank and instead ran approximately 800 meters to the next nearest phone in the fear of causing a detonation of the released vapour cloud. The fourth possibility may also have some bearing in the crisis as prior to this event, the term BLEVE had still not been discovered or at least recorded prior to this. The rest of the sequence should be covered in the full breakdown of the crisis. An important issue to be considered is the overall control displayed by both the emergency and municipal authorities during the crisis. Even though the A7 expressway was closed following the leak, the authorities failed to close the local roads to all traffic, which resulted in a car being within 160 meters of the leaking pressure tank and causing the point of ignition. The failings in the emergency service appear to be more in association with a lack of sufficient training in the order of dealing with industrial crises as it was primarily there to deal with public situations. This resulted in a fatal misunderstanding of how to control such a situation as a leaking pressure tank and resulting fire, due to a lack of prior knowledge which is strengthened in the term BLEVE only being created some 4 to 5 years later Results of the enquiry and official recommendations The official investigation was not fully resolved until 1971 by the Grenoble court case. This may have been due to political reasons or due to the enquiry investigating why the crisis had occurred in the first place. On the principal that such events have happened since the Feyzin disaster, it cannot be assumed that the enquiry was successful in bringing about sufficient change in the safety of pressurised fluid containment. Personal recommendations not covered by the enquiry The first recommendations are for the design and construction of all current and future proposed plants dealing with pressurised fluid containment. The second recommendations are in association with work practices involved on chemical plants in general. Third valve (reserve): A third valve should be installed for the purpose of maintenance and crisis control. To be kept open at all times so as not to induce unnecessary wear and tear on the valve. When maintenance is required to be carried out on the two principal valves, the reserve can be shut to allow for maintenance to be carried out safely. In the event of a crisis similar to that of Feyzin, this valve can be shut as an emergency back up system in minimising fluid leakage from the pressure vessel. ‘Cold' pipe lagging: In order to prevent freezing of any pipes or valves dealing with potentially ‘cold' fluids, lagging should be fitted to all appropriate pipe work and fittings in order to minimise any potential freezing of these systems. Systems not dealing with ‘cold' fluids must be scrutinised independent of this point. Rubber sealed pressure box: High pressure boxes should be installed around all vital valves dealing with pressurised fluids. They should be big enough to allow for ease of working but not to big as to incur any additional hazard to plant running. They should be designed with an environmental rubberised seal so that if a valve begins to leak, the box can but locked shut with an emergency key. Thus minimising any excessive leakage until the situation can be bought under control. See: A third valve (reserve) Deluge system – Control box and master switch: If geographically located near to a natural water source as in the case of the Feyzin site, a deluge system should be installed. It must have pipe work leading to all critical locations around the entirety of the plant. This system must be regularly checked so as to remain in good working order. Each piece of equipment covered by this system must be fitted with a local switch, so in the event of either a leak or a fire, the operator can activate the system in order to prevent escalation of the situation. A central control post should be equipped with a control panel covering all local deluge systems via an override system and also be installed with a master switch that can activate all systems at once. This will allow for the main operator to activate systems in a sequence or all at once should a major sit6uation occur. Communication is vital for this system to work properly, so an emergency phone network should be installed in order to insure proper working of the system. This will only be part of the solution and fire brigades properly trained with dealing with such an event will ensure that the crisis is resolved effectively. Completion of site before going online: It is important that a site should be safe to operate before going online. In the case of Feyzin, the site was still under construction when the accident occurred. Even though construction work may not have been the cause of the incident, neither can the incompletion of the site be assumed to have helped in the scale of the incident itself. So before a plant can go online, all safety systems must be installed. This is not to be confused with site maintenance which is an ongoing process throughout the plants lifetime. Inclusion of full earthworks around site: Only effective if any vapour or fluid is heavier than atmospheric air. May also be affected by environmental conditions, however if all other systems are overwhelmed, then this system is designed to delay the spread of any possible leak. Earth works should be built around all containment vessels and if possible the entire site. So in case of an emergency, any leaking vapour may be contained within the confines of either the leaking vessel or the plant. Fig. 2 illustration of valves which were major cause of accident Preventions To prevent valves from freezing redundant sampling valves and drain valves are installed in series. In the tank involved in this accident, the double valve was already installed. In the LPG tank, the doubling of the valve is a minimum requirement as in the case of a single valve, there is a strong possibility that the valves main body will be cooled, damaging the closing function of the valve by freezing of the moisture in the air. The distance between the two valves must be sufficient to prevent the low temperature of the second valve affecting it. The size of the second valve must be approximately 10mm or less. It is recommended that a distance of 1m or more to be allowed between valve 1 and 2. Counter measures in other facilities around the world * Dike installation: – LPG spreads along the ground as it is heavier than the air. A dike is effective for prevention the spread of LPG. * As a precaution against the BLEVE phenomenon, the tank wall must be cooled by placing water showering facilities above the tank. * The Tank legs must be fire proofed. If the legs are made from iron they can be damaged by fire. * The distance between tanks is kept to prevent the spread of fires. The minimum distance is generally the diameter of the larger tank, however if possible greater distance between tanks is recommended. * Gas detectors are installed within the facility. Conclusions The Feyzin accident was a cause by human error and unsafe conditions. The accident could have been prevented if correct procedures were followed and if the plant was designed with appropriate fail safe systems such as a dike and LPG detectors. This accident lead to a greater understanding of the BLEVE phenomenon and has given future LPG companies the knowledge of its existence which has led to further research into this occurrence. Explosion of LPG tanks cause devastating damage. The companies that store and handle large volumes of LPG must consult with the local government to ensure they can communicate with the local government, inform local inhabitants and relay instructions for how to restrict traffic in case of an LPG leak. It has now become clear that the location for which the plant is located must be thoroughly studied, to ensure there is enough distance between the plant and built up areas. Without doubt future companies designing LPG refinery plants can benefit from the findings of this accident report. Glossary BLEVE – Boiling Liquid Expanding Vapour Explosion LPG – Liquefied Petroleum Gas

Kant s Philosophy Of The State And Analysis Of Historical...

Compromised largely in Kant s ideas, Hegel s systemic philosophy of the State and analysis of historical summit of the body politic provides the foundation of Marxism and alike. Hegel declares the concept of state as superior to the individual. In his book Philosophy of History, he establishes Reason as the rational manifestation of world history which subsists in both natural and spiritual realms; But the Spirit, and the course of its development, is the substance of history (20). Reason as the core of Spirit is the self-contained existence of itself as that which is free and autonomous. Thus the Idea is that world history is Spirit attempting to find its own nature. Hence, the union and harmony of the Idea and human private†¦show more content†¦Hegel presents the State as the epitome of individual freedom in a set of institutions, just like Christ is represented as the epitome of God in Christian history. The more a State is free, insofar it is rational and the highest fo rm of Spirit, the closer it is to the State itself. Marx critiques Hegel’s conception of the State in his book Capital as â€Å"standing on its head† (302). He refutes the claim that the state sustains civil society; rather, Marx stresses, it is the most natural interdependent bond of the family and civil society which are the necessary essence of the state. His assertion that â€Å"...the ideal is nothing else than the material world reflected by the human mind, and translated into forms of thought† (301) reestablishes Hegel’s idealist approach. The state is incapable of maintaining itself without social consciousness produced by production, which Marx takes to be the legal, political, and intellectual structure of society. Hence it is the economic life of free mankind in civil society which manifests the state. Democracy is the only true harmony of the particular and the general. Marx explains that â€Å"In democracy, the constitution, the law, the state itself, insofar as it is a political constitution, is only the self-determination of the people, and a particular content of the people† (21). Marx explains that until now the political constitution has been the religious

I Watched It Die By Teresa Sandoval - 889 Words

She watched it die. At the top of her apartment complex, above families and lovers, perched a figure on the ledge of the rooftop. It stood above layers of humanity in that complex, liveliness indicated by the lights shining through the different curtains and blinds covering most of the windows of the complex. The figure stepped closer to the edge, its head turned to Teresa Sandoval. The silhouette reminded her of a woman: the harsh wind pulled back its hair and a sheet cascaded down the building. The smell of red wine and smoke stung her eyes. Teresa stood underneath the one working streetlight on the entire street: all the other lights flickered. As the figure moved closer to the edge, the lights flickered even more. The buzzing grew louder. Teresa’s cheeks were red from the alcohol she had downed only fifteen minutes earlier and the cold wind slapping against her cheeks. She leaned against the pole, her burning eyes still fixed on the shadow as it halted right up to the ledge. She glanced quickly at the pavement in front of her then right up to the figure. The moon shone brightly behind the figure, long black hair illuminated. As it walked closer, the lights behind the windows at the feet of the figure were killed. She felt like she was at a shootout with an unknown enemy. She pretended the sweat slicking her neck was from the hot desert air, that her eyes were stinging from the sand flying to her face. Teresa scratched her wrist, a habit of hers when nerves consume