Made available in DSpace on 2014-12-17T14:55:40Z (GMT). No. of bitstreams: 1 FabianoMA.pdf: 3389870 bytes, checksum: 6be9485b031563d3dfbff4f86c5c0c69 (MD5) Previous issue date: 2009-10-23 / Petr?leo Brasileiro SA - PETROBRAS / Pipeline leak detection is a matter of great interest for companies who transport petroleum and its derivatives, in face of rising exigencies of environmental policies in industrialized and industrializing countries. However, existing technologies are not yet fully consolidated and many studies have been accomplished in order to achieve better levels of sensitivity and reliability for pipeline leak detection in a wide range of flowing conditions. In this sense, this study presents the results obtained from frequency spectrum analysis of pressure signals from pipelines in several flowing conditions like normal flowing, leakages, pump switching, etc. The results show that is possible to distinguish between the frequency spectra of those different flowing conditions, allowing recognition and announce of liquid pipeline leakages from pressure monitoring. Based upon these results, a pipeline leak detection algorithm employing frequency analysis of pressure signals is proposed, along with a methodology for its tuning and calibration. The proposed algorithm and its tuning methodology are evaluated with data obtained from real leakages accomplished in pipelines transferring crude oil and water, in order to evaluate its sensitivity, reliability and applicability to different flowing conditions / A detec??o de vazamentos em dutos ? assunto de grande interesse para empresas que realizam o transporte de petr?leo e seus derivados, tendo em vista o crescente rigor da legisla??o ambiental nos pa?ses industrializados e em processo de industrializa??o. No entanto, as tecnologias existentes hoje ainda n?o est?o plenamente consolidadas e estudos v?m sendo realizados com vistas a atingir maiores n?veis de sensibilidade e confiabilidade para a detec??o de vazamentos em uma ampla variedade de regimes de escoamento. Neste sentido, este estudo apresenta os resultados obtidos com a an?lise do espectro de freq??ncia de sinais de press?o de oleodutos em diversas situa??es de escoamento, tais como escoamento normal, vazamentos, partida e parada de bombas, etc. Os resultados indicam que ? poss?vel diferenciar o espectro freq?encial dessas diferentes condi??es de escoamento, o que permite reconhecer e indicar a ocorr?ncia de vazamentos em dutos transportando fluidos l?quidos a partir da monitora??o de sua press?o. Com base nestes resultados, s?o propostos um algoritmo para detec??o de vazamentos em dutos utilizando a an?lise freq?encial de sinais de press?o e uma metodologia para sintonia e calibra??o deste algoritmo. O algoritmo e a metodologia de sintonia propostos s?o avaliados com dados obtidos a partir de vazamentos reais provocados em dutos transferindo petr?leo e ?gua, a fim de avaliar sua sensibilidade, confiabilidade e aplicabilidade para diferentes condi??es de escoamento

Made available in DSpace on 2014-12-17T14:55:41Z (GMT). No. of bitstreams: 1 AlvaroMA_DISSERT.pdf: 1811875 bytes, checksum: d1a8b9710060f420383a8d715381bfb9 (MD5) Previous issue date: 2009-12-23 / Embedded systems are widely spread nowadays. An example is the Digital Signal Processor (DSP), which is a high processing power device. This work s contribution consist of exposing DSP implementation of the system logic for detecting leaks in real time. Among the various methods of leak detection available today this work uses a technique based on the pipe pressure analysis and usesWavelet Transform and Neural Networks. In this context, the DSP, in addition to do the pressure signal digital processing, also communicates to a Global Positioning System (GPS), which helps in situating the leak, and to a SCADA, sharing information. To ensure robustness and reliability in communication between DSP and SCADA the Modbus protocol is used. As it is a real time application, special attention is given to the response time of each of the tasks performed by the DSP. Tests and leak simulations were performed using the structure of Laboratory of Evaluation of Measurement in Oil (LAMP), at Federal University of Rio Grande do Norte (UFRN) / Os sistemas embarcados est?o amplamente difundidos atualmente. Um exemplo ? o Digital Signal Processor (DSP), que ? um dispositivo com alto poder de processamento. A contribui??o deste trabalho consiste na implementa??o em DSP da l?gica de um sistema de detec??o de vazamentos em tempo real. Dentre os v?rios m?todos de detec??o de vazamentos existentes atualmente este trabalho se desenvolve utilizando uma t?cnica baseada na an?lise da press?o no duto e que utiliza Transformada Wavelet e Redes Neurais. Nesse contexto o DSP, al?m de realizar o processamento digital do sinal de press?o, tamb?m comunica-se com um Global Positioning System (GPS), que auxilia na localiza??o do vazamento e com um sistema supervis?rio, disponibilizando informa??es para este. Para garantir robustez e confiabilidade na comunica??o entre DSP e sistema supervis?rio ? utilizado o protocolo Modbus. Como trata-se de uma aplica??o de tempo real, uma aten??o especial ? dada ao tempo de resposta de cada uma das tarefas realizadas pelo DSP. Os testes e simula??es de vazamentos foram realizados utilizando a estrutura do Laborat?rio de Avalia??o de Medi??o em Petr?leo (LAMP), da Universidade Federal do Rio Grande do Norte (UFRN)

Este trabalho tem como objetivo global contribuir para o desenvolvimento do estudo da propagação de ondas em dutos de transporte de fluidos, especialmente oleodutos e gasodutos, através da análise da atenuação acústica e da velocidade de propagação da onda. Para isso, foram feitos ensaios experimentais, tanto em escoamento mono quanto bifásico, variando-se a vazão do escoamento em uma linha de testes de 1500 metros e 50 mm de diâmetro, para aquisição de sinais gerados a partir do fechamento de válvulas de simulação de vazamentos em pontos ao longo da tubulação. Para análise da atenuação acústica foi proposta uma metodologia baseada na medição do coeficiente de amortecimento temporal das ondas de pressão como subsídio para o cálculo do coeficiente de atenuação, através da utilização de um único sensor de pressão. Esta metodologia foi validada pela medição direta do coeficiente de atenuação e os resultados mostram uma excelente concordância em escoamentos monofásicos. Para os testes em escoamento bifásico não foi possível aplicar esta metodologia devido ao forte amortecimento das ondas de pressão, sendo feitas apenas medições diretas da atenuação com resultados fenomenologicamente coerentes. A velocidade de propagação acústica para escoamento monofásico foi influenciada pela presença de gás dissolvido e bolhas de cavitação, apresentando valores próximos aos da literatura para baixas vazões de escoamento. Para altas vazões, as velocidades foram compatíveis com o escoamento bifásico a bolhas finamente dispersas. Para o escoamento bifásico o regime de escoamento variou de bolhas a pistonado. As velocidades de propagação obtidas são compatíveis com aquelas obtidas por modelos teóricos. / This work aims to contribute to the development of the study of wave propagation in fluid transport pipelines, through the analysis of acoustic attenuation and propagation speed. For this reason, experimental tests were made in single and two-phase flow, varying the flow rate in a test line of 1500 meters and 50 mm in diameter, for the acquisition of signals generated from the closing of leak simulation valves at known points along the pipeline. To analyze the acoustic attenuation it was proposed a methodology based on measurement of temporal damping coefficient of pressure waves as input for calculating the attenuation coefficient, by using a single pressure sensor. This methodology was validated by direct measurement of attenuation coefficient and the results show an excellent agreement in single-phase flow. For the tests in two-phase flow it was not possible to apply this methodology due to the strong damping of pressure waves, which only made direct measurements of attenuation results phenomenologically consistent. Acoustic propagation velocity for single phase flow was influenced by the presence of dissolved gas and cavitation bubbles, having values close to the literature for low flow rates. For high flows rates, the velocities were consistent with a two-phase flow at finely dispersed bubbles. For the two-phase flow the regime varied from slug to bubbles. The propagation velocities obtained are consistent with those obtained by theoretical models.

Orientadores: Celso Kazuyuki Morooka, Ivan Rizzo Guilherme / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica, Instituto de Geociencias / Made available in DSpace on 2018-08-03T22:11:53Z (GMT). No. of bitstreams: 1 Silva_HenriqueVenturada_M.pdf: 6776642 bytes, checksum: 0f63d0ee9cc11e83387d78ccd3d5500c (MD5) Previous issue date: 2003 / Resumo: O meio mais eficiente e econômico para transportar derivados de petróleo são os dutos. Porém, o controle dos riscos associados a um vazamento acidental é fundamental. Esta questão tem motivado o desenvolvimento de vários métodos para detecção de vazamentos, a maioria deles baseados na observação de variáveis de processo já normalmente acompanhadas. Nesta dissertação, uma forte correlação existente entre o desvio apurado no balanço das vazões e os transientes operacionais é identificada e utilizada na definição da estratégia apresentada aqui, que consiste, em dois módulos, desenvolvidos para identificar, em tempo-real, os diversos transientes que ocorrem no processo, classificando-os em estados operacionais pré definidos e detectando falhas do processo de transferência - dentre elas, vazamento - baseado no modelo de balanço de volume, utilizando a classificação dos transientes identificados de modo a reduzir a ocorrência de alarmes espúrios na detecção de vazamentos ou de outra condição anormal do processo. Estes módulos foram construídos com a utilização de duas técnicas baseadas em lógica nebulosa: Sistemas de Inferência Nebulosa e Redes Neurais Nebulosas. Os sistemas foram testados com novos dados coletados do mesmo processo, e os resultados obtidos comparados entre si. Foi constatado que as soluções são promissoras, considerando a simplicidade na construção dos modelos, obtendo-se bom desempenho na detecção pequenos vazamentos com baixo custo computacional e grande confiabilidade / Abstract: Pipeline is an efficient and economic means of transporting petroleum products. However, risks associated with accidental release of transported product are still high. That issue has motivated the development of many methods for leak detection, mainly based on process variables. In the present dissertation, the high correlation between the inlet-outlet flowrate deviation and the operational transients is shown which is the important fact to define the fault detection strategy present here. The applied strategy consists, at first, in a development of classifier module that can identify the operational and process transients and determine the current stage of the transfer process. The output of this module is used by a Fault Detection module that can evaluate the inlet-outlet flowrate deviation in order to detect a leak or a abnormal operation condition, with a low level of spurious alarms. Two fuzzy methods were used to solve this problem: A Fuzzy Inference System using a rule-base developed from this database and a Neural Fuzzy Network using the same role-base. The systems were evaluated with a new data collected from the same process and the results are encouraging with increased leakage or abnormal situation detection, low computational costs and low level of spurious alarms / Mestrado / Explotação / Mestre em Ciências e Engenharia de Petróleo

Syfte: Syftet är att genom en strukturell jämförelse av fallstudiens undersökningsobjekt få en överblick över kostnaden för arbetsutförandet av två luttätnings- och provtryckningsmetoder. Detta för att ta fram vilken metod som är lämpligast att tillämpa med avseende på kostnad.  Metod: Metoderna som tillämpats för att besvara målet var observationer, mätningar, beräkningar, litteraturstudie samt intervjuer. Den huvudsakliga metoden som användes var observationstekniken ”observatör som deltagare”. Intervjuer tillämpades för att anbringa ny kunskap men även verifiera empirin hämtad från observationerna.  Resultat: Studien visar att det finns både mindre och markanta skillnader mellan objektens lufttätnings- och provtryckningsmetoder som genererar både för och nackdelar. De största skillnaderna var framförallt vid fönster- och dörrutförandet, materialvalet i installationsväggen och om en tidig provtryckning utförs eller inte. Fördelarna med Gripen var att de inte var beroende av utomstående aktörers utförande vid fönsteranslutningen samt att de hade ett moment mindre under kontrollen av klimatskalet. Studien visar även att Gripen hade en lägre totalkostnad för lufttäthetsarbetet än Vimans Trädgård. Dock var kostnaden per kvadratmeter desto högre för varje färdigställd kvadratmeter. Efter en noggrann strukturell jämförelse bedömdes Vimans Trädgårds tillvägagångssätt var den mest kostnadseffektiva lufttätnings- och provtryckningsmetoden utifrån kr/kvm, se Tabell 13. Konsekvenser: Studien visar att båda objektens metoder fungerar för att nå byggnadens ställda lufttäthetkrav. Då metoderna liknade varandra på många punkter kunde slutsatsen dras att lufttätningsutförandet av fönster- och dörranslutningar hade en stor inverkan på tiden samt kostnaden. Slutligen kan följande rekommendationer ges, en byggnads lufttäthet bör säkerställas i ett tidigt skede, företagens luftätningsmetoder bör fortsätta utvecklas samt en enhetlig lufttätnings- och provtryckningsmetod bör utformas och appliceras inom hela företaget. Begränsningar: Rapportens undersökningsstrategi är en kvantitativ fallstudie. Studien begränsas till fallstudiens båda undersökningsobjekt och deras lufttätnings- samt provtryckningsmetod utan avseende till materialkostnader. Undersökningen begränsas även till objektens förutsättningar som materialval men tar ingen hänsyn till geografisk placering eller väderstrecksorientering. Detta medför att studien är giltig under specifika förhållanden. Vid en eventuell upprepning kan studien påvisa andra resultat och generera skilda slutsatser än det som vidtagits i denna utredning. / Purpose: The purpose is to provide an overview of the cost of the work performance of two air tightening and pressure testing methods through a structural comparison of the case study's investigative objects. This is to find out which method is most appropriate to apply in terms of cost. Method: The chosen methods, used to answer the goal, were observations, measurements, calculations, literature studies and interviews. The main method used was the observation technique "observer as a participant". Interviews were applied to conceive new knowledge, but also to verify the information from the observations. Findings: The study shows that there are both minor and significant differences between the objects air tightening and pressure testing methods that generate both pros and cons. The main differences were mainly the execution of the windows and doors, the choice of materials in the installation wall and if an early pressure test is performed or not. The benefits of Gripen were that they were not dependent on external operator’s performance at the window connection and that they had a moment less under the control of the climate scale. The study also shows that Gripen had a lower total cost of air tightness than Vimans Trädgård. However, the cost per square meter was the higher for each completed square meter. After a careful structural comparison, Vimans Trädgård ́s approach was evaluated as the most cost-effective air tightening and pressure testing method, see Table 13.  Implications: The study shows that the air tightening methods of both objects work to reach the building's airtightness requirements. As the methods were similar at many points, it could be concluded that the air tightening of window- and door connections had a major impact on time as well as the cost. Finally, the following recommendations that can be given is, building airtightness should be ensured at an early stage, companies' air tightening and pressure testing methods should continue to evolve and a uniform air tightening and pressure testing method should be designed and applied throughout the companies. Limitations: The report's investigation strategy is a quantitative case study. The study is limited to two study objects of the case study and their air tightening and pressure testing method without regard to material costs. The investigation is also limited to the object's conditions as material choice, but does not consider geographical location or weather-orientation. This means that the study is valid under specific conditions. In the event of a repeat, the study can demonstrate other results and generate different conclusions than those undertaken in this investigation.

Orientadores: Sandra Lucia da Cruz, João A. F. R. Pereira / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-07-31T22:23:21Z (GMT). No. of bitstreams: 1 Souza_ArlanLucasde_D.pdf: 3739716 bytes, checksum: 40314e4f8359d3c06b6df822abda9f09 (MD5) Previous issue date: 2002 / Resumo: Uma nova técnica de detecção de vazamentos em tubulação é apresenta­da. A técnica é baseada na análise espectral de sinais de pressão medidos em trechos da tubulação que favorecem a formação de ondas estacionárias. Sendo baseada no espectro do sinal, e não na sua representação temporal, a análise possibilita a identificação do vazamento mesmo quando este ocorre durante a realização de operações que naturalmente encobririam o transiente de pressão gerado pelo vazamento. Testes experimentais foram realizados numa tubulação de 1250 m de comprimento em várias condições de fluxo e configurações de vazamento durante a partida e a parada de uma bomba centrífuga. Transientes de pressão foram obtidos por quatro transdutores conectados a um computador padrão PC comandado por um software de aquisição de dados e controle desenvolvido. Os testes mostraram que a análise espectral dos transientes de pressão, juntamente com o conhecimento dos pontos de reflexão na tubulação, consiste em um método simples e eficiente de se detectar vazamentos / Abstract: The development and test of a technique for leak detection in pipelines is presented. The technique is based on the spectral analysis of pressure signals measured in pipeline sections where the formation of stationary waves is favoured, allowing leakage detection during the start stop of pumps. Experimental tests were performed in a 1250 m long pipeline for various operational conditions of the pipeline (liquid flow rate and leakage configuration). Pressure transients were obtained by four transducers connected to a PC compute. The obtained results show that the spectral analysis of pressure transients, together with the knowledge of reflection points provide a simple and efficient way of identifying leaks during the start stop of pumps in pipelines / Doutorado / Sistemas de Processos Quimicos e Informatica / Doutor em Engenharia Química

This work deals with the automatic testing of an ultrasonic gas leak detector, which has to be tested during normal changes in the development phase. The reader will be acquainted with the basic principles of gas detection, design of the test product, software architecture its implementation. The following is a presentation of the application and instructions for writing tests. In this work, the Beaglebone Black development board with the Debian operating system is used as the core of the entire test product.

<p>UVOD: Drenaža grudnog ko&scaron;a nakon resekcija pluća je osnovni grudno hirur&scaron;ki postupak, koji omogućuje pro&scaron;irenje (reekspanziju) pluća iz kolabiranog stanja, evakuaciju vazduha, krvi i izliva iz pleuralnog prostora i potpomognuta je primenom aspiracije na drenove (sukciona ili aspiraciona drenaža). Iako je drenaža&nbsp; svakodnevna grudno hirur&scaron;ka procedura, postupak sa drenovima je zasnovan prvenstveno na iskustvu, a manje na osnovu naučnih studija. Pri mirnom disanju inspiratorni pritisak u pleuralnom prostoru je prosečno - 8 cm H2O, a ekspiratorni - 4 cm H2O. Pri forsiranom disanju pritisci mogu dostići - 50 cm H2O i +70 cm H2O. Na osnovu tih fiziolo&scaron;kih podataka, većina hirurga primenjuje aspiraciju od - 10 do - 40 cm H2O. Koncepta pleuralnog deficita - disproporcije volumena preostalog plućnog tkiva i zapremine grudnog ko&scaron;a doveo je do razvoja tehničkih postupaka za postizanje nove fiziolo&scaron;ke ravnoteže u pleuralnom prostoru i razmatranja rutinske primene podvodne (pasivne) drenaže nakon resekcija pluća. Pritisak na zdravstvenu službu za smanjenje tro&scaron;kova i skraćenje postoperativne hospitalizacije uz mogućnost rane mobilizacije pacijenta čine podvodnu drenažu zanimljivom alternativom tradicionalno prihvaćenoj aktivnoj aspiraciji na drenove.&nbsp; CILJ: Da se utvrdi da li aplikacija aktivne aspiracije na drenove nakon lobektomije pluća u poređenju da podvodnom drenažom ima povoljno terapijsko dejstvo na postizanje i održavanje reekspanzije pluća; Da se kvantitativno uporede različiti modovi aktivne aspiracije preko drenova; Da se uporedi dužina hospitalizacije i pojava hirur&scaron;kih i nehirur&scaron;kih komplikacija između grupa ispitanika kod kojih se primenjuje podvodna (pasivna) drenaža i aspiracija preko drenova. METODOLOGIJA: Prospektivna studija bez randomizacije obuhvatila je 301 ispitanika kojima je načinjena lobektomija pluća zbog karcinoma pluća na Klinici za grudnu hirurgiju Instituta za plućne bolesti Vojvodine u Sremskoj Kamenici u periodu od 01.01.2008. - 28.02.2010. godine. Beleženi su i analizirani podaci o preoperativnom stanju: plućnoj funkciji, prethodno primljenoj neoadjuvantnoj hemioterapiji i pridruženim bolestima. Analizirani su hirur&scaron;ki operativni podaci o postojanju buloznog emfizema, adhezija u pleuralnom prostoru, anatomskoj vrsti lobektomije, dodatnim hirur&scaron;kim procedurama i postojanju gubitka vazduha na kraju operacije. Analizirani su postoperativni podaci o secernaciji na drenove tokom prva 24 h i ukupno, trajanju gubitka vazduha na drenove u danima, ukupnom trajanju drenaže, ukupnom trajanju hospitalizacije, pojavi produženog gubitka vazduha na dren definisanog kao gubitak duže od 7 dana, potrebi za redrenažom grudnog ko&scaron;a (broj drenova upotrebljenih za redrenažu), kompletnost reekspanzije pluća pre vađenja drenova, pojavi drugih hirur&scaron;kih komplikacija, pojavi op&scaron;tih medicinskih komplikacija i pojavi kasnih komplikacija &ndash; vi&scaron;e od 30 dana nakon operacije ili nakon otpusta. Prvu grupu ispitanika sačinjavaju pacijenti kojima je načinjena lobektomija pluća, nakon čega je aplikovana aspiracija od -20 cm vodenog stuba do klemovanja i vađenja drenova. Drugu grupu ispitanika sačinjavaju pacijenti kojima je aplikovana aspiracija od -20 cm vodenog stuba na dan operacije i zatim -10 cm vodenog stuba do klemovanja i vađenja drenova. Treću grupu ispitanika sačinjavaju pacijenti kojima je načinjena lobektomija pluća, nakon čega je aplikovana aspiracija od -20 cm vodenog stuba na dan operacije i zatim podvodna drenaža do klemovanja i vađenja drenova. Četvrtu grupu ispitanika sačinjavaju pacijenti kojima je načinjena lobektomija pluća, nakon čega je aplikovana aspiracija od -20 cm vodenog stuba na dan operacije i zatim dnevna procena i modifikacija na sledeći način: aspiracija od -20 cm vodenog stuba do postizanja reekspanzije pluća, zatim postepeno smanjenje aspiracije po nahođenju operatera do klemovanja i vađenja drenova. REZULTATI: Između grupa ispitanika ne postoji statistički značajna razlika po starosti (p=0,77),&nbsp; parametrima plućne funkcije: vrednost FEV1 (p=0,6316), vrednost ITGV (p=0,6202), vrednost TLC (p=0,6922) i za vrednost RV ne postoji razlika (p=0,6552). Razlika ne postoji između grupa ni u učestalosti pridruženih bolesti (p=0,4522). Grupe su međusobno homogene po preoperativnim parametrima. Snižen FEV1 u ukupnoj populaciji pacijenata nije uticao na pojavu produženog gubitka vazduha (P=0,571), kao ni povi&scaron;enje ITGV (P=0,22), RV (p=0,912), niti vrednost TLC (0,521). Upoređene su međusobno osnovne vrste lobektomija: desna gornja, leva gornja, desna donja, leva donja, srednja lobektomija, kao i donja i gornja bilobektomija desno. Kako je učestalost svake pojedinačne lobektomije u 4 grupe ispitanika mali da bi se uporedile iste lobektomije između grupa, poređenje je moguće samo između anatomski različitih lobektomija kumulativno u svim grupama. Razlika u pojavi produženog gubitka vazduha između različitih lobektomija postoji, ali nije dostigla statističku značajnost (p=0,061). Međutim, kada se analizira svaka lobektomija pojedinačno, uočava se da desna donja bilobektomija ima značajno veću učestalost produženog gubitka vazduha u odnosu na sve ostale lobektomije zajedno (P=0,009). Razlika u dužini drenaže kod&nbsp; različitih lobektomija je dostigla statistički značaj (p=0,0356), kao i u ukupnoj dužini hospitalizacije (p=0,0007). Dodatak resekcije perikarda, grudnog zida ili dijafragme, klinasta resekcija susednog režnja ili sleeve resekcija bronha kao dodatne procedure nisu uticali na pojavu produženog gubitka vazduha (p=0,58). Podaci o učestalosti adhezija u ispitivanoj populaciji pacijenata i njihovom uticaju na pojavu produženog gubitka vazduha daju granične vrednosti. I ovde je broj pacijenata u svakoj pojedinačnoj kategoriji adhezija (postojanje adhezija na skali od 0-3) mali da bi testiranje povezanosti sa produženim gubitkom vazduha moglo dostići statističku značajnost - razlika postoji, ali nije značajna (p=0,065). Radi povećanja statističke snage je izvedeno testiranje za podelu ima ili nema adhezija. Razlika postoji, ali ni ovim testiranjem nije dostignuta statistički značajna razlika (p=0,057). Postojanje buloznog emfizema takođe dovodi do povećanja učestalosti produženog gubitka vazduha, ali ni ovde razlika nije značajna (p=0,063).&nbsp; Primena hemoterapije pre operacije nije dovela do statistički značajne razlike u pojavi produženog gubitka vazduha (p=0,0623) i ukupnoj stopi komplikacija (p=0,088), kao ni dužine hospitalizacije (p=0,2), iako razlika postoji i paradoksalno rezultat je bolji kod pacijenata koji su primili hemioterapiju, &scaron;to može ukazivati na uticaj selekcije pacijenata za operaciju. Između 4 grupe ispitanika nije uočena razlika u potrebi za redrenažom grudnog ko&scaron;a (p=0,101), potrebi za povećanjem nivoa aktivne aspiracije (p=0,326), ukupnoj pojavi komplikacija (p=0,087) i pojavi produženog gubitka vazduha (P=0,323). Razlika postoji i visoko je značajna u dužini trajanja drenaže (p=0,001) i dužini hospitalizacije (P=0,000). Broj drenova (1 ili 2 drena postavljena intraoperativno) nije uticao na pojavu produženog gubitka vazduha (p=0,279), ali je značajno kraća hospitalizacija kod pacijenata sa jednim drenom (p=0,0001). Logistička regresiona analiza je pokazala da je samo donja bilobektomija značajno uticala na pojavu produženog gubitka vazduha na dren, dok nije nađen uticaj aktivne aspiracije na drenove, prisustva adhezija, buloznog emfizema, sniženih vrednosti FEV1, primene redukcije pleuralnog prostora (space reducing), broja drenova i dodatne operacije (resekcije). ZAKLJUČAK: Sprovedenim istraživanjem utvrđeno je da primena aktivne aspiracije na drenove ne pokazuje razliku u odnosu na podvodnu drenažu u postizanju i održavanju reekspanzije pluća nakon lobektomije. Aktivna aspiracija ne utiče na pojavu produženog gubitka vazduha na drenove definisanog kao gubitak vazduha duže od 7 dana, ali utiče na produženje ukupnog trajanja drenaže i hospitalizacije. Nivo aktivne aspiracije ili primena dnevnih modifikacija nivoa aspiracije ne utiče na rezultate lečenja.&nbsp; U ovom istraživanju preoperativna plućna funkcija, kao ni preoperativna hemoterapija ne utiču na pojavu produženog gubitka vazduha na drenove. Desna donja bilobektomija u odnosu na sve druge lobektomije dovodi do če&scaron;će pojave produženog gubitka vazduha, produžene drenaže i hospitalizacije. Dodatne resekcije okolnih tkiva u sklopu lobektomije ili primena redukcije pleuralnog prostora ne utiču na pojavu produženog gubitka vazduha. Intraoperativni nalaz adhezija u pleuri i buloznog emfizema pluća povećavaju rizik produženog gubitka vazduha, ali je taj uticaj na granici statističke značajnosti. Primena jednog drena nakon lobektomije umesto dva ne utiče na pojavu produženog gubitka vazduha, ali utiče na skraćenje drenaže i hospitalizacije. U multivarijatnoj analizi samo je donja bilobektomija značajno uticala na pojavu produženog gubitka vazduha na dren, dok nije nađen uticaj aktivne aspiracije na drenove, prisustva adhezija, buloznog emfizema, sniženih vrednosti FEV1, primene redukcije pleuralnog, broja drenova i dodatne resekcije okolnih tkiva.</p> / <p>INTRODUCTION: The drainage of the thorax after pulmonary resection is a basic thoracic surgery procedure which enables reexpansion after lung collapse and the evacuation of air, blood and effusion from the pleural cavity. It is supported by the use of drainage aspiration (suction or aspiration drainage). Although drainage is an everyday procedure in thoracic surgery, the use of drains is based mainly on specialist experience and less on scientific research. During calm breathing the inspiratory pressure in the pleural cavity is &ndash; 8cm H2O on average, while the expiratory pressure is &ndash; 4cm H2O. During forced breathing the pressures can reach up to &ndash; 50 cm H2O and + 70 cm H2O. Based on this physiological data, most surgeons apply the aspiration from &ndash; 10 to &ndash; 40 cm H2O. The concept of pleural deficit (the disproportion of the volume of the remaining pulmonary tissue and the volume of the thorax) has attributed to development of new technical procedures in order to achieve a new physiological balance in the pleural cavity. It has also brought upon the consideration of routine underwater seal drainage after pulmonary resection. Underwater seal drainage represents an interesting alternative to the traditional active drainage aspiration, especially considering the need to reduce medical expenses and shorten the postoperative hospitalization period. AIM: To determine whether active drainage aspiration after pulmonary lobectomy has a favorable therapeutic effect on achieving and maintaining pulmonary reexpansion in comparison with underwater seal drainage; to quantitatively compare the different modes of active drainage aspiration; to compare hospitalization duration and surgical and non-surgical complication with groups of patients on whom either underwater seal drainage or aspiration drainage was applied. METHODOLOGY: The prospective study without randomization has covered 301 patients on whom pulmonary lobectomy was performed due to lung carcinoma at the Thoracic Surgery Clinic of the Institute of Pulmonary Diseases of Vojvodina from 1st January 2008 to 28th February 2010. The data collected in the pre-operative state included: pulmonary function, previous neoadjuvant chemotherapy and comorbidities. In the research, surgical operative data and postoperative data were analyzed. Surgical operative data included information about the bullous emphysema, adhesion in the pleural cavity, anatomic type of lobectomy, additional surgical procedures and air leak after surgery. Postoperative data involved information about amount of fluid on drainage during the first 24 hours and in total, air leak duration in days, total drainage period, overall hospitalization period, prolonged air leak defined as leak longer than 7 days, the need for redrainage of thorax (number of tubes used for redrainage), completeness of pulmonary reexpansion before the end of drainage, other surgical complications, comorbidities and late complications (after more than 30 days following the surgery or release). The first group consists of patients on whom pulmonary lobectomy was performed, after which an aspiration of &ndash; 20 cm H2O was applied before clamping and tube extraction. The second group consists of patients on whom pulmonary lobectomy was performed, after which an aspiration of &ndash; 20 cm H2O was applied on surgery day and again &ndash; 10 cm H2O before clamping and tube extraction. The third group consists of patients on whom pulmonary lobectomy was performed, after which an aspiration of &ndash; 20 cm H2O was applied on surgery day and underwater seal drainage was applied before clamping and tube extraction. The fourth group consists of patients on whom pulmonary lobectomy was performed, after which an aspiration of &ndash; 20 cm H2O was applied on surgery day, and then daily monitored and modified in such a way that an aspiration of &ndash; 20 cm H2O was applied until pulmonary reexpansion and then gradually lowered according to individual surgery experience before clamping and tube extraction. RESULTS: There is no significant statistical difference between groups of patients in: age (p=0.77), FEV1 (p=0.6316), ITGV (p=0.6202), TLC (p=0.6922) and RV (p=0.6552) and comorbidities (p=0.4522). The groups are homogenous in pre-operative parameters. Lowered FEV1 among all patients did not affect prolonged air leak (p=0.571), nor the increase in values of ITGV (p=0.22), RV (p=0.912) and TLC (p=0.5211). The lobectomies that were compared were: upper right, upper left, lower right, lower left, middle, as well as upper and lower right bilobectomy. The comparison was implemented only on anatomically different lobectomies cumulatively among groups, due to the low occurrence of each type of lobectomy in groups. The difference in prolonged air leak does exist, but is not statistically significant (p=0.061). Prolonged air leak has a significantly higher occurrence in lower right bilobectomies (p=0.009). Drainage duration and hospitalization period variations in different kinds of lobectomy are statistically significant (p=0.0356 and p=0.0007, respectively). Additional pericardial, thoracic or diaphragm resection, wedge resection of the neighboring lobe, or sleeve bronchial resection did not affect prolonged air leak (p=0.58). The research has established that the occurrence of adhesion (on a scale 0-3) in patients and bulous emphysema attribute to prolonged air leak (p=0.065 and p=0.063, respectively).&nbsp; Comparison between patients with and without adhesions revealed similar result. Difference exists, but it is not statistically significant (p=0,057).&nbsp; Pre-operative chemotherapy had no statistical significance on prolonged air leak (p=0.0623), total rate of complications (p=0.088), nor hospitalization period (p=0.2). Paradoxically, the treatment was in favor of those patients who had taken pre-operative chemotherapy, which could be due to the selection of patients for surgery.&nbsp; Among the four groups, there was no difference in need for thoracic redrainage (p=0.101), need for increase in level of active aspiration (p=0.326), overall complication occurrence (p=0.087) and prolonged air leak occurrence (p=0.323). There is a statistically significant difference in drainage duration (p=0.001) and hospitalization period (p=0.000). The number of tubes (1 or 2 tubes set intraoperatively) did not affect prolonged air leak occurrence (p=0.279). The hospitalization period in patients with one tube set intraoperatively is significantly shorter (p=0.0001). Logistic regression analysis has shown that only lower bilobectomy had a significant impact on prolonged air leak, unlike active drainage aspiration, the presence of adhesions, bullous emphysema or lowered FEV1 values, pleural cavity space reducing, number of tubes and resection. CONCLUSION: The research has shown: Active drainage aspiration has no difference in effect in achieving and maintaining pulmonary reexpansion after lobectomy when compared to underwater seal drainage; Active drainage aspiration does not affect prolonged air leak, defined as air leak longer than 7 days; Active drainage aspiration has an impact on the overall drainage duration and hospitalization period; The level of active drainage aspiration and daily modification of the mentioned do not affect treatment results; Preoperative pulmonary function does not affect prolonged air leak occurrence; Preoperative chemotherapy does not affect prolonged air leak occurrence; Prolonged air leak and drainage and hospitalization period occur most often in lower right bilobectomies; Nor additional resections nor pleural cavity reduction affect prolonged air leak occurrence; The presence of pleural adhesions and bullous emphysema rarely attribute to the increase of prolonged air leak occurrence; The number of tubes implemented intraoperatively does not affect prolonged air leak occurrence, but it shortens drainage and hospitalization periods; By multivariate analysis, that only lower bilobectomy has a significant impact on prolonged air leak, unlike active drainage aspiration, the presence of adhesions, bulous emphysema or lowered FEV1 values, pleural cavity space reducing, number of tubes and resection.</p>

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