functional evaluation of candidates for lung resection for the treatment of lung cancer 
 can be guided by various algorithms , of which the most known are those proposed by the 
 consensus guidelines of the american college of chest physicians ( accp ) and the european 
 respiratory society / european society of thoracic surgeons . although the use of these 
 tools would potentially reduce morbidity and mortality rates , their application is 
 compromised , because tests that are not readily available for most physicians , such as 
 dlco measurement and , especially , cardiopulmonary exercise testing ( cpet ) , are 
 required . the main difference between the two algorithms lies in the referral for those tests , 
 although there have been no studies comparing the superiority of one over the other . however , it has been reported that , when no algorithm was used , evaluation errors were 
 common , with the highest frequency of these errors occurring among less experienced 
 physicians . 
  having been published before the european algorithm , the accp algorithm has been used in 
 the preoperative evaluation center of the federal university of so paulo in the last 10 
 years . the objective of this study was to share our experience by providing morbidity 
 and mortality rates by risk category , as well as to report the role played by dlco 
 measurement and cpet in this categorization process and the risk factors associated with 
 perioperative complications ( pcs ) . this was a historical cohort study of a database of preoperative evaluations of patients 
 diagnosed with or clinically suspected of having lung cancer , performed at the 
 hospital so paulo , located in the city of so paulo , brazil , 
 between january 1 , 2001 and december 31 , 2010 . the project was approved by the research 
 ethics committee of the federal university of so paulo ( protocol no . the evaluation algorithm proposed by the accp consensus guidelines was applied after 
 patients had achieved their best clinical and functional status . all patients underwent spirometry , and referral for dlco measurement 
 occurred when there was clinical and radiological suspicion of concomitant interstitial 
 disease , when there was a history of neoadjuvant chemotherapy , or when the intensity of 
 dyspnea reported was disproportionate to the measured fev1 as a percentage of 
 the predicted value . referral for cpet occurred when either predicted postoperative 
 fev1 ( fev1ppo ) or predicted postoperative dlco ( dlcoppo ) was 
 less than 40% , or when the patient was unable to perform acceptable dlco measurement 
 maneuvers . patients who were unable to perform cpet properly were classified as being at 
 high risk . ppo : 
 predicted postoperative ; cpet : cardiopulmonary exercise testing ; and vo2peak : 
 peak oxygen uptake . in the post - operative period , patients received physical therapy and pain management 
 from specialized teams until they were discharged from the hospital . the outcome measures analyzed , i.e. , morbidity and mortality rates , included events 
 occurring by postoperative day 30 . described in a previous study , the definitions of pcs were 
 as follows : respiratory or cardiovascular events causing intraoperative instability ; 
 lower respiratory tract infection ; atelectasis ; acute respiratory failure ; acute 
 myocardial infarction ; atrial arrhythmia requiring treatment ; congestive heart failure ; 
 bronchopleural fistula ; pleural empyema ; air leak lasting 7 days or longer ; hemothorax ; 
 reoperation ; and need for oxygen therapy on postoperative day 30 . in the statistical analysis , morbidity and mortality rates are expressed as simple 
 percentages . in order to determine whether the functional values were associated with 
 pcs , we had to recalculate them , adjusting them to the extent of the resection performed 
 rather than maintaining them in accordance with the planned resection . the resulting 
 values were called true fev1ppo and true dlcoppo . in order to identify which 
 variables were correlated with pcs , we used pearson 's chi - square test and the student 's 
 t - test . of the 262 who were eligible for the study , 239 ( 91.2% ) underwent all steps of the accp 
 algorithm , whereas 23 ( 8.8% ) did not . the clinical and functional characteristics of 
 those 239 patients are shown in table 1 . table 1demographic , clinical , and pulmonary function data of the 239 candidates 
 evaluated . 
  in 156 patients ( 65.3% ) , fev1 was > 80% or fev1ppo was > 
 40% , and no other tests were needed to complete the evaluation . however , 8 patients 
 ( 3.3% ) had a fev1ppo < 40% and were therefore referred for cpet . however , 6 of those 
 82 did not undergo dlco measurement because they were unable to perform acceptable 
 maneuvers . of the 76 remaining patients , 60 ( 73.2% ) had fev1ppo and dlcoppo 
 values > 40% predicted and were classified , at the end of the preoperative 
 evaluation , as being at an acceptable risk of pcs . of the 14 patients who had a dlcoppo 
 < a total of 23 patients ( 9.6% ) were 
 referred for cpet , and 13 ( 56.5% ) of them were classified as being at high risk for the 
 following reasons : having a peak oxygen uptake < 15 ml  kg min ( 6 patients ) ; performing submaximal exercise or being unable to 
 pedal ( 4 patients ) ; not having undergone cpet because of an unknown reason ( 2 patients ) ; 
 and not having undergone cpet because the machine was broken ( 1 patient ) . figure 2 illustrates the application of the 
 algorithm , which classified 13 patients ( 5.4% ) as being at high risk of pcs and 226 
 ( 94.6% ) as being at an acceptable risk . figure 2preoperative evaluation of 239 lung resection candidates as per the 
 american college of chest physicians algorithm guidelines . ppo : predicted 
 postoperative ; cpet : cardiopulmonary exercise testing ; and vo2peak : peak oxygen 
 uptake . six of them did not undergo 
 resection of lung parenchyma and were therefore disregarded in the remaining analyses . 
 of the remainder , 139 and 6 were classified as being at an acceptable and high risk , 
 respectively . in 49.6% of those procedures , the amount of parenchyma resected was 
 smaller than planned ; in most cases , because malignant disease was ruled out by 
 intraoperative frozen - section analysis . in 9.3% , a greater amount of tissue was resected 
 because of the progression of cancer . the following procedures were performed : lobectomy 
 ( in 38.6% of the cases ) ; resection of less than one segment ( in 29.0% ) ; segmentectomy 
 ( in 17.9% ) ; pneumonectomy ( in 8.3% ) ; bilobectomy ( in 4.8% ) ; and bisegmentectomy ( in 
 1.4% ) . of the 145 patients operated on , 49 had pcs , the morbidity rate being 33.8% and the 
 overall mortality rate being 5.5% ( 8 deaths ) . there were 101 pcs , the most common being 
 prolonged air leak ( in 19.8% ) , lower airway respiratory infection ( in 19.8% ) , and acute 
 respiratory failure ( in 17.8% ) , followed by cardiac arrhythmia ( in 7.9% ) , need for 
 reoperation ( in 5.9% ) , home oxygen therapy ( in 5.9% ) , pleural empyema ( in 5.9% ) , 
 atelectasis ( in 5.0% ) , acute myocardial infarction ( in 5.0% ) , bronchopleural fistula ( in 
 4.0% ) , and intraoperative events ( in 3.0% ) . there were no statistically significant differences between operated and non - operated 
 patients in terms of age , prevalence of comorbidities , prevalence of copd , or 
 fev1 as a percentage of the predicted value . the most common reasons 
 preventing surgical treatment were progression of cancer , treatment discontinuation or 
 dropout , and a diagnosis of benign disease by a method other than the initially planned 
 surgery . a diagnosis of malignancy was confirmed in 105 operated patients ( 72.4% ) , adenocarcinoma 
 being the most common histological type ( in 40.0% ) . in 27.6% of the patients , the 
 histological diagnoses were benign , the majority ( 59.5% ) corresponding to nonspecific 
 benign lesions and tuberculomas . morbidity and mortality rates for patients classified preoperatively as being at an 
 acceptable risk of pcs were , respectively , 31.6% and 4.3% ( 6 deaths ) , whereas those for 
 patients at high risk were 83.3% and 33.3% ( 2 deaths ) . in the reclassification of 
 patients by extent of the procedure , 4 of the 139 patients classified as being at an 
 acceptable risk would be referred for cpet so that the evaluation could be completed . of 
 the 6 patients classified as being at high risk , 4 remained so and 2 were reclassified 
 as being at an acceptable risk . after recalculation , morbidity and mortality rates were , 
 respectively , 31.4% and 3.6% for those at an acceptable risk and 100% and 50.0% for 
 those at high risk . table 2 shows the morbidity 
 and mortality rates of patients classified as being at an acceptable risk , by tests 
 performed . table 2morbidity and mortality rates of the 137 patients reclassified as being at 
 an acceptable risk of perioperative complications after the surgical procedure , 
 by tests performed . 
  in a comparison of patients who had pcs with those who did not , statistically 
 significant differences were found in the following variables : age ; lobe resection ; true 
 fev1ppo as a percentage of the predicted value ; and copd ( table 3 ) . table 3comparison between the groups of patients with and without perioperative 
 complications in terms of age , presence of copd , presence of other 
 comorbidities , size of resection , and pulmonary function parameters . the use of the accp algorithm showed that , among patients classified as being at high 
 risk of pcs , the mortality rate was seven to thirteen times higher than was that 
 observed for those classified as being at an acceptable risk . this difference occurred 
 in the context of overall morbidity and mortality rates being consistent with those 
 reported by other health care facilities . this finding revealed that the algorithm provided a 
 good prediction of patient risk , identifying those who require more attention and 
 investment both before and after the procedure . whereas only calculation of fev1ppo was needed in the evaluation of the 
 majority of the study population , who had a favorable postoperative course , a dlcoppo 
 value < 40% determined the need for cpet five times more often than did a 
 fev1ppo value < 40% . however , considering the subgroup of patients who 
 underwent this test , the risk level did not change in 75% of the cases . this result was 
 unexpected , given that dlco has gained much prominence in postoperative evaluation in 
 recent years , with several studies demonstrating that dlco is more accurate for 
 predicting risk of pcs than is fev1 . a likely explanation for this is loss of 
 discriminatory power of dlco when dlco is included in an algorithm that classifies 
 patients into only two categories . however , it should also be considered that , if our 
 sample was bigger or if all patients had undergone dlco measurement , the results could 
 perhaps be different , allowing even the creation of other categories , such as the 
 moderate risk category . certainly , cpet is the method of choice for surgical risk stratification even outside 
 the field of thoracic surgery ; however , it is not widely available . our results showed that , when cpet is used 
 after a series of tests that identified a patient as having limited reserve , which 
 corresponded to only 9.6% of our population , the risk would be high in 56.6% of the 
 cases . however , it is necessary to consider that the observed rates of pcs and mortality 
 were very high . in our view , the algorithm used was designed in such a way that the 
 high - risk category corresponded to " very high risk " , and , therefore , the algorithm 
 should be improved by the inclusion of intermediate - risk categories . according to the european algorithm , cpet should be performed when the predicted 
 fev1 or dlco value is below 80% , i.e. , in the initial phase of the 
 evaluation . , who had this test available 
 at their facility and developed an algorithm on the basis of it . in contrast , the 
 cost - effectiveness of this approach as compared with that of simpler evaluation 
 strategies , especially in low - risk patients , is unknown . if we had applied the european 
 algorithm to our sample , 81.7% of the population should have undergone cpet . a recent 
 study conducted in spain showed that , when six hospitals used that algorithm , of the 92 
 patients ( 53.2% ) of the study sample who had been referred for cpet , only 68 underwent 
 the test . in most cases , the test was not performed because of a lack of technical 
 infrastructure . 
  during the review process of our manuscript , the third revision of the accp guidelines 
 for the evaluation of lung resection candidates was published . a new algorithm , 
 extrapolated from a number of studies , was proposed , but , unfortunately , it was not 
 validated in a large , multicenter , prospective study . in comparison with the 2007 
 guidelines , these new guidelines agree with the european algorithm that all resection 
 candidates should undergo dlco measurement , as well as including the use of submaximal 
 exercise tests before cpet , the development of new parameters for categorizing low risk , 
 and the creation of a moderate - risk category . therefore , when fev1ppo and 
 dlcoppo were above 60% , patients would be classified as being at low risk . if either of 
 these parameters was between 30% and 60% , patients would be referred for the shuttle 
 test or the stair - climbing test . depending on the results obtained , patients would 
 undergo cpet , the results of which would determine whether the patient would be 
 classified into the low - risk , moderate - risk , or high - risk category . in an attempt to simplify the dynamic evaluation of cardiopulmonary reserve , much 
 research has been conducted on submaximal exercise tests , such as the stair - climbing 
 test , the six - minute walk test ( 6mwt ) , and the shuttle test .   despite the satisfactory findings 
 reported , some negative points have been observed . the lack of standardization of the 
 stair - climbing test , the low level of evidence of the 6mwt , the variability of effort 
 exerted during the tests , and , first and foremost , the fact that none of these tests 
 measure more complex metabolic and cardiopulmonary parameters reserved for them the role 
 of ascertaining if the patient really was at low risk of pcs . the european consensus 
 guidelines and the accp consensus guidelines agree that patients who perform poorly on 
 these tests should undergo cpet . it is likely that further studies will discuss whether 
 or not the strategy of using submaximal exercise tests within the new algorithm will 
 prove sufficiently discriminatory and cost - effective . given these findings , we suspect that the major problem may lie in the proposed 
 algorithms rather than in the availability of the tests . in an attempt to verify this 
 suspicion , our suggestion would be to start the investigative process after determining 
 which pcs would be considered significant for this type of procedure , in order to 
 determine the morbidity rate . goals would then be set on the basis of morbidity and 
 mortality rates considered tolerable for each risk category . investigations would 
 identify which tests and which results would be needed in order to achieve each goal , 
 determining how much accuracy would be gained by including more sophisticated tests in 
 each category . an algorithm designed in such a way would perhaps give greater assurance 
 to the surgeon and the patient , as well as resulting in better use of more complex tests 
 and of multidisciplinary teams as risk increased . this reasoning results from the 
 difficulty we face in comparing the rates of pcs and death found in the present study 
 with those reported in other studies , as well as from the hypothesis formulated on the 
 basis of our findings , i.e. , cpet plays a more decisive role in differentiating between 
 the high - risk and very high - risk categories and in clinical treatment . although cpet is available at our facility , we will continue to recommend it only for 
 patients with limited reserve , because , since ours is a public health care facility , we 
 do not have sufficient resources or logistics capacity to meet the demand generated by 
 the use of the european algorithm . in addition , as seen in table 2 , the morbidity and mortality rates obtained for the 
 acceptable - risk category by using spirometry and dlco measurement were satisfactory . it means longer 
 hospital stays , a greater delay in resuming work and social activities , and higher 
 medical and hospital expenses , as well as adding to the risk of sequelae or death . as in 
 recent studies , one possible explanation could be care in 
 recognizing and treating cardiac comorbidities prior to evaluation for resection , a 
 recommendation made by both the accp algorithm and the european algorithm . studies have 
 shown that the implementation of a preoperative cardiac evaluation algorithm contributed 
 to proper use of tests and therapeutic strategies , reducing cardiac morbidity 
 rates . another contributing factor would be advances in 
 the diagnosis and treatment of dyslipidemia , systemic arterial hypertension , diabetes 
 mellitus , and coronary artery disease , reducing the systemic inflammatory state . it remains controversial whether advanced age alone is a risk factor for 
 pcs or whether the severity 
 and number of comorbidities that affect older patients are responsible for these 
 complications . the prevalence rate of comorbidities found in our 
 study was similar to or lower than those reported in other studies , as well as being similar between the groups with 
 and without pcs . the opposite was true for the presence of copd and the extent of 
 resection , which are known to be the two most important risk factors related to 
 pcs . therefore , we prioritized addressing complications that have the 
 greatest impact , have established definitions , and had been used in other studies 
 conducted at out facility , such as pulmonary infection , acute respiratory failure , and 
 bronchopleural fistula . the second limitation was the modest number of patients studied , 
 which precluded more complex statistical analysis . however , this is the first report of 
 the use of the accp algorithm in brazil . the third limitation was the possibility that 
 critically ill patients were not referred to our outpatient clinic because they had 
 previously been considered as being at very high risk . therefore , the findings of the 
 present study should not be generalized . in conclusion , the use of the accp algorithm allowed the identification of a group of 
 patients whose morbidity and mortality rates were considerably higher , requiring more 
 attention throughout the perioperative period . the majority of our population was 
 evaluated on the basis of spirometry alone and had acceptable morbidity and mortality 
 rates . however , cpet played an important role in the identification of high - risk 
 patients . in agreement with published studies , advanced age , copd , lobe resection , and 
 poorer pulmonary function determinar as taxas de morbidade e mortalidade por categoria de risco conforme as 
 diretrizes do american college of chest physicians , verificar 
 como exames funcionais participaram dessa categorizao e identificar fatores de 
 risco para complicaes perioperatrias ( cpos ) . estudo de coorte histrica a partir de avaliaes pr e ps - operatrias de casos 
 diagnosticados ou suspeitos de cncer de pulmo avaliados entre 2001 e 2010 . dos 239 pacientes avaliados , apenas 13 ( 5,4% ) foram considerados como de alto 
 risco para cpos . o clculo do vef1 previsto para o ps - operatrio 
 ( vef1ppo ) foi suficiente para a estratificao do risco em 156 
 pacientes ( 65,3% ) ; entretanto , o teste de exerccio cardiopulmonar ( tecp ) foi 
 necessrio para a identificao de alto risco . foram operados 145 pacientes , e as 
 taxas globais de morbidade e mortalidade encontradas foram semelhantes s de 
 outros estudos . entretanto , as taxas de morbidade e mortalidade para aqueles com 
 risco aceitvel foram de 31,6% e 4,3% , respectivamente , enquanto as taxas para 
 aqueles com alto risco foram de 83,3% e 33,3% . idade mais avanada , presena da 
 dpoc , resseco de um ou mais lobos e vef1ppo mais baixo estiveram 
 relacionados  ocorrncia de cpos . embora a espirometria tenha sido suficiente para a determinao de risco na 
 maioria da populao estudada , o tecp teve papel fundamental na identificao de 
 pacientes com risco alto , que apresentaram uma taxa de mortalidade sete vezes 
 maior que os de risco aceitvel . a avaliao funcional de candidatos  resseco pulmonar para tratamento do cncer de 
 pulmo pode ser orientada por diversos algoritmos , sendo os mais conhecidos os 
 propostos pelos consensos do american college of chest physicians 
 ( accp ) 
 e da european respiratory society / european society of thoracic 
 surgeons . apesar da potencial reduo nas taxas de 
 morbidade e mortalidade que a utilizao dessas ferramentas proporcionaria , sua 
 aplicao est comprometida , pois so necessrios exames pouco disponveis para a 
 maioria dos mdicos , como a medida da dlco e , especialmente , o teste de exerccio 
 cardiopulmonar ( tecp ) . 
  a principal diferena entre os dois algoritmos est na indicao desses exames , mas 
 ainda no h estudos comparando a superioridade de um em relao ao outro . entretanto , h trabalhos relatando que , quando no se utilizara nenhum algoritmo , os 
 erros na avaliao foram comuns , recaindo sobre os mdicos menos experientes a maior 
 frequncia desses erros . 
  por ter sido publicado anteriormente ao europeu , o algoritmo do accp tem sido 
 utilizado pelo setor de avaliao pr - operatria da universidade federal de so paulo 
 nos ltimos 10 anos . objetivamos compartilhar nossa experincia apresentando as taxas 
 de morbidade e mortalidade segundo a categorizao de risco , relatar como a dlco e o 
 tecp participaram dessa categorizao e quais fatores de risco estiveram associados  
 ocorrncia de complicaes perioperatrias ( cpos ) . realizou - se a anlise de um banco de dados de uma coorte histrica de avaliaes 
 pr - operatrias realizadas no hospital so paulo , localizado na cidade de so paulo 
 ( sp ) , no perodo entre 1 de janeiro de 2001 e 31 de dezembro de 2010 , em pacientes 
 que tinham cncer de pulmo j diagnosticado ou sua suspeita clnica . o projeto 
 obteve aprovao do comit de tica da universidade federal de so paulo ( no . 1487/11 ) . o algoritmo de avaliao proposto pelo consenso do accp foi aplicado aps o paciente 
 encontrar - se na sua melhor condio clnico - funcional . a figura 1 ilustra o algoritmo e a categorizao do risco 
 operatrio . todos os pacientes realizaram espirometria , e a pesquisa da dlco era 
 indicada quando havia suspeita clnica e radiolgica de doena intersticial 
 concomitante , quimioterapia neoadjuvante prvia ou intensidade de dispneia referida 
 desproporcional ao valor obtido no vef1 em percentual do previsto . quando 
 um dos dois valores funcionais previstos para o ps - operatrio ( ppo ) , isto  , 
 vef1ppo ou dlcoppo , era inferior a 40% ou quando o paciente era incapaz 
 de realizar manobras aceitveis para a mensurao da dlco , o tecp foi indicado . ppo : 
 previsto no ps - operatrio ; tecp : teste de exerccio cardiopulmonar ; e 
 vo2pico : consumo de oxignio no pico do exerccio . 
  no ps - operatrio , os pacientes receberam assistncia fisioteraputica e manejo da 
 dor por equipes especializadas at a alta hospitalar . as medidas de desfecho analisadas , isto  , as taxas de morbidade e mortalidade , 
 consideraram os eventos ocorridos at o 30 dia de ps - operatrio . as definies de 
 cpos foram descritas em um estudo prvio 
  e eram as seguintes : intercorrncias respiratrias ou cardiovasculares 
 que provocaram instabilidade no perodo intraoperatrio ; infeco do trato 
 respiratrio inferior ; atelectasia ; insuficincia respiratria aguda ; infarto agudo 
 do miocrdio ; arritmia atrial com necessidade de tratamento ; insuficincia cardaca 
 congestiva ; fstula broncopleural ; empiema pleural ; perda area por 7 ou mais dias ; 
 hemotrax ; reoperao ; e necessidade de oxigenoterapia no 30 dia de 
 ps - operatrio . na anlise estatstica , as taxas de mortalidade e morbidade foram apresentadas como 
 proporo simples . para avaliar se os valores funcionais estavam associados  cpos , 
 foi necessrio recalcul - los , ajustando - os  extenso da resseco realizada ao invs 
 de mant - los em conformidade  resseco planejada , sendo denominados 
 vef1ppo real e dlcoppo real . para identificar quais variveis estiveram 
 relacionadas  ocorrncia de cpos , foi utilizado o teste do qui - quadrado de pearson e 
 o teste t de student . dos 262 pacientes elegveis para o estudo , 239 ( 91,2% ) foram avaliados segundo o 
 algoritmo do accp , enquanto as etapas recomendadas pelo consenso no foram cumpridas 
 em 23 ( 8,8% ) . as caractersticas clnico - funcionais desses 239 pacientes encontram - se 
 na tabela 1 . tabela 1dados demogrficos , clnicos e de funo pulmonar dos 239 candidatos 
 avaliados . os valores previstos para vef1 foram > 80% ou vef1ppo > 
 40% em 156 pacientes ( 65,3% ) , no sendo necessrios outros exames para se concluir a 
 avaliao . entretanto , 8 pacientes ( 3,3% ) apresentaram vef1ppo < 40% e 
 portanto tiveram indicao de realizar o tecp . dos 239 pacientes , 82 ( 34,3% ) tiveram indicao de realizar a dlco ; porm , 6 desses 
 no o fizeram porque foram incapazes de realizar manobras aceitveis . dos 76 
 pacientes restantes , 60 ( 73,2% ) apresentaram valores de vef1ppo e de 
 dlcoppo > 40% do previsto , concluindo sua avaliao pr - operatria como com risco 
 aceitvel . dos 14 pacientes com dlcoppo < 40% , 13 apresentavam vef1ppo 
 > 40% . no total , 23 pacientes ( 9,6% ) tiveram indicao de realizar o tecp , sendo 
 que 13 ( 56,5% ) foram categorizados como pacientes com alto risco pelos seguintes 
 motivos : apresentar consumo de oxignio no pico do exerccio < 15 ml  
 kg  min , em 6 ; realizar esforo submximo ou no 
 conseguir pedalar , em 4 ; no realizar o tecp por motivos desconhecidos , em 2 ; e no 
 realizar o tecp porque o aparelho estava quebrado , em 1 . a figura 2 ilustra a aplicao do algoritmo , que categorizou 13 
 pacientes ( 5,4% ) como com alto risco e 226 ( 94,6% ) como com risco aceitvel . figura 2avaliao pr - operatria de 239 candidatos  resseco pulmonar segundo 
 as orientaes do algoritmo do american college of chest physicians . ppo : 
 previsto no ps - operatrio ; tecp : teste de exerccio cardiopulmonar ; e 
 vo2pico : consumo de oxignio no pico do exerccio . em 6 deles , no houve resseco de parnquima 
 pulmonar e , portanto , foram desconsiderados para as demais anlises . do restante , 139 
 e 6 pertenciam aos grupos com risco aceitvel e alto risco , respectivamente . em 49,6% 
 desses procedimentos , foi ressecado menos parnquima do que o programado ; na maioria 
 das vezes , pela excluso de doena maligna na anlise de congelao no 
 intraoperatrio . foram realizadas lobectomias em 38,6% dos casos ; resseces menores que um 
 segmento , em 29,0% ; segmentectomias , em 17,9% ; pneumonectomias , em 8,3% ; 
 bilobectomias , em 4,8% ; e bissegmentectomias , em 1,4% . dos 145 pacientes operados , 49 apresentaram cpos , sendo a taxa de morbidade de 33,8% 
 e a de mortalidade geral de 5,5% ( 8 bitos ) . ocorreram 101 cpos , sendo as mais 
 frequentes a perda area prolongada , em 19,8% ; a infeco respiratria das vias 
 areas inferiores , em 19,8% ; e a insuficincia respiratria aguda , em 17,8% ; seguidas 
 por arritmia cardaca , em 7,9% ; necessidade de reoperao , em 5,9% ; oxigenoterapia 
 domiciliar , em 5,9% ; empiema pleural , em 5,9% ; atelectasia em 5,0% ; infarto agudo do 
 miocrdio , em 5,0% ; fstula broncopleural , em 4,0% ; e intercorrncias 
 intraoperatrias , em 3,0% . no houve diferenas estatisticamente relevantes nas comparaes feitas entre os 
 pacientes operados e no operados em relao a idade , prevalncia de comorbidades , 
 prevalncia de dpoc e vef1 em porcentagem do previsto . as causas mais 
 frequentes que impossibilitaram o tratamento operatrio foram progresso do cncer ; 
 abandono ou desistncia do tratamento ; e diagnstico de doena benigna por outro 
 mtodo que no a operao inicialmente programada . o diagnstico de malignidade foi confirmado em 105 pacientes operados ( 72,4% ) , sendo 
 o adenocarcinoma o tipo histolgico mais frequente ( 40,0% ) . em 27,6% dos pacientes , o 
 diagnstico histolgico foi benigno , a maioria ( 59,5% ) correspondendo a leses 
 benignas no especificadas e tuberculomas . as taxas de morbidade e mortalidade dos pacientes categorizados no pr - operatrio 
 como com risco aceitvel foram de , respectivamente , 31,6% e 4,3% ( 6 bitos ) , 
 enquanto , naqueles com alto risco , essas foram de 83,3% e 33,3% ( 2 bitos ) . na 
 recategorizao dos pacientes conforme a extenso do procedimento realizado , dos 139 
 pacientes que pertenciam ao grupo com risco aceitvel , 4 teriam indicao de realizar 
 o tecp para concluir a avaliao . dos 6 pacientes considerados como com alto risco , 4 
 assim permaneceram , e 2 foram recategorizados como com risco aceitvel . recalculando 
 as taxas de morbidade e mortalidade , respectivamente , essas foram de 31,4% e 3,6% 
 para aqueles com risco aceitvel , e de 100% e 50,0% para aqueles com alto risco . a 
 tabela 2 mostra as taxas de morbidade e 
 mortalidade obtidas no grupo de pacientes categorizados como com risco aceitvel de 
 acordo com os exames realizados . tabela 2taxas de morbidade e mortalidade dos 137 pacientes pertencentes ao 
 grupo com risco aceitvel , recategorizados aps o procedimento operatrio , 
 conforme os exames realizados . comparando os pacientes que apresentaram cpos com aqueles sem cpos , foi observado que 
 somente as variveis idade , realizao de resseces em um ou mais lobos , 
 vef1ppo real em porcentagem do previsto e dpoc como comorbidade 
 apresentaram diferenas estatisticamente significativas ( tabela 3 ) . tabela 3comparao entre os grupos de pacientes que apresentaram ou no 
 complicaes perioperatrias em relao a idade , presena de dpoc , presena 
 de outras comorbidades , porte da resseco e os parmetros da funo 
 pulmonar . a utilizao do algoritmo do accp mostrou que os pacientes categorizados como com 
 risco alto apresentaram uma taxa de mortalidade de sete a treze vezes superior  
 encontrada naqueles considerados como com risco aceitvel . essa diferena ocorreu 
 estando as taxas globais de mortalidade e morbidade condizentes s relatadas por 
 outros servios . esse dado permitiu constatar que o algoritmo 
 ofereceu uma boa predio de risco para esses pacientes , identificando aqueles que 
 merecem mais ateno e investimento tanto antes quanto aps o procedimento . enquanto a maioria da populao estudada precisou apenas do clculo de 
 vef1ppo para ser avaliada e apresentou evoluo ps - operatria 
 favorvel , o valor de dlcoppo < 40% determinou a necessidade de se realizar o tecp 
 cinco vezes mais frequentemente do que o valor de vef1ppo < 40% . porm , 
 considerando o subgrupo de pacientes submetido a esse exame , no houve uma 
 modificao do risco em 75% dos casos . esse resultado no era esperado , uma vez que a 
 dlco ganhou muito destaque na avaliao pr - operatria nos ltimos anos , quando 
 vrios estudos demonstraram que a dlco  mais acurada para predizer o risco de cpos 
 do que o vef1 . uma provvel explicao para isso seria a perda 
 do poder discriminatrio da dlco quando inserida em um algoritmo que categoriza os 
 pacientes em apenas duas classes . mas tambm h de se considerar que , se nossa 
 amostra fosse maior ou se a dlco tivesse sido realizada em todos os pacientes , talvez 
 os resultados pudessem ser diferentes , permitindo at a criao de outras categorias , 
 como a de risco moderado . o tecp  , sem dvida , o exame de eleio na estratificao do risco operatrio mesmo 
 fora da cirurgia torcica ; porm ,  muito pouco disponvel . nossos resultados mostraram que , quando 
 o tecp  utilizado aps uma sequncia de exames que identificaram um paciente com 
 reserva limitada , o que correspondeu a apenas 9,6% da nossa populao , o risco seria 
 alto em 56,5% das vezes . porm ,  necessrio atentar que as taxas de cpos e de morte 
 encontradas foram muito altas . no nosso entendimento , da maneira como o algoritmo 
 utilizado foi concebido , essa categoria espelhou um " risco muito alto " , e , portanto , 
 deveria haver um aprimoramento do algoritmo com a insero de categorias de risco 
 intermedirias s existentes . segundo o algoritmo europeu , o tecp deve ser realizado quando o previsto de 
 vef1 ou de dlco estiver abaixo de 80% , isto  , na fase inicial da 
 avaliao . , que dispunham desse exame no seu servio e 
 elaboraram um algoritmo a partir dele . por outro lado , no se conhece a relao 
 custo - efetividade dessa proposio comparada a outras estratgias mais simples de 
 avaliao , principalmente em pacientes com baixo risco . se tivssemos aplicado o 
 algoritmo europeu na nossa amostra , o tecp deveria ter sido feito em 81,7% da 
 populao . uma recente publicao espanhola mostrou que quando seis hospitais 
 utilizaram aquele algoritmo , dos 92 pacientes ( 53,2% ) da amostra total do estudo que 
 tinham indicao para a realizao do tecp , somente 68 o fizeram . na maioria das 
 vezes , a no realizao desse exame se deu pela falta de estrutura 
 tcnica . no processo de reviso de nosso manuscrito , foi publicada a terceira reviso das 
 orientaes da accp para candidatos  resseco pulmonar . foi proposto um novo 
 algoritmo , extrapolado de um elenco de publicaes , mas , infelizmente , sem que um 
 grande estudo prospectivo e multicntrico o tivesse validado . comparativamente  
 publicao de 2007 , as novidades trazidas foram a concordncia com o algoritmo 
 europeu em relao  realizao da medida da dlco em todos os candidatos a resseco , 
 a utilizao de testes submximos antes do tecp , novos parmetros para categorizar o 
 risco baixo e a criao de uma categoria de risco moderado . assim , quando o 
 vef1ppo e a dlcoppo estivessem acima de 60% , os pacientes seriam 
 classificados como com baixo risco . se qualquer um desses valores estivesse entre 30% 
 e 60% , os testes de shuttle ou de escada estariam indicados . a 
 depender dos resultados obtidos , o tecp seria realizado e seus resultados definiriam 
 se o paciente pertenceria s categorias de risco baixo , moderado ou alto . na tentativa de simplificar a avaliao dinmica da reserva cardiopulmonar , muito se 
 pesquisou a respeito dos testes de exerccios submximos , como os testes de escada , 
 de caminhada de seis minutos ( tc6 ) e de shuttle . a falta de padronizao do 
 teste de escada , o baixo nvel de evidncia do tc6 , a variabilidade do esforo 
 empregado durante os testes e , principalmente , a falta de avaliao de parmetros 
 metablicos e cardiopulmonares mais complexos em quaisquer desses testes reservaram a 
 eles o papel de confirmar se o paciente realmente apresentava um risco baixo de cpos . os consensos europeu e da accp concordam que pacientes com desempenho insatisfatrio 
 nesses testes deveriam realizar o tecp . provavelmente , novos estudos discutiro se a 
 estratgia de utilizao de testes submximos inseridos no novo algoritmo se mostrar 
 suficientemente discriminatria e custo - efetiva . frente a esses achados , questionamos se o maior problema no estaria nos algoritmos 
 propostos ao invs da disponibilidade dos exames . na tentativa de responder essa 
 dvida , nossa sugesto seria de iniciar o processo investigativo aps a determinao 
 de quais cpos seriam consideradas significativas para esse tipo de procedimento para 
 compor a taxa de morbidade . a partir da , seriam estipuladas metas balizadas por 
 taxas de morbidade e de mortalidade consideradas tolerveis para cada categoria de 
 risco . pesquisas avaliariam quais exames e quais resultados seriam necessrios para 
 se atingir cada meta , determinando quanto de acurcia ganharamos com a adio de 
 exames mais sofisticados em cada uma das categorias . talvez , concebido assim , o 
 algoritmo traria maior segurana ao cirurgio e ao paciente e faria com que a 
 necessidade de exames mais complexos e a participao de um time multiprofissional 
 fossem mais bem aproveitadas conforme o risco aumentasse . esse raciocnio  fruto da 
 dificuldade que enfrentamos ao comparar nossas taxas de cpos e morte com as das 
 demais publicaes e da hiptese levantada pelos nossos resultados , ou seja , que o 
 tecp tem um papel mais decisivo na diferenciao das categorias de risco alto e muito 
 alto , assim como em relao ao tratamento clnico . sendo assim , apesar de o tecp estar disponvel na nossa instituio , continuaremos a 
 indic - lo apenas para pacientes com reserva limitada , pois , como servio pblico , no 
 h recursos e logstica suficientes para corresponder a demanda trazida pelo uso do 
 algoritmo europeu . alm disso , como observado na tabela 2 , as taxas de morbidade e de mortalidade obtidas para a categoria 
 com risco aceitvel utilizando - se espirometria e dlco foram satisfatrias . para o paciente , significa maior tempo de 
 internamento hospitalar , maior atraso na retomada de suas atividades laborais e 
 sociais e maiores despesas mdico - hospitalares , alm de adicionar maior risco de 
 sequelas ou de morte . assim como em recentes publicaes , a taxa de complicaes 
 cardacas observadas foi menor do que as pulmonares . uma possvel explicao poderia ser o cuidado 
 em reconhecer e tratar comorbidades cardacas antes de se iniciar a avaliao para a 
 resseco , recomendao dada tanto pelo algoritmo do accp quanto pelo europeu . estudos mostraram que a implementao de um algoritmo de avaliao cardaca 
 pr - operatria contribuiu para o uso apropriado de exames e estratgias teraputicas , 
 reduzindo as taxas de morbidade cardaca . outro fator contribuinte seria o avano no 
 diagnstico e tratamento da dislipidemia , hipertenso arterial sistmica , diabetes 
 mellitus e insuficincia coronariana , reduzindo o estado inflamatrio sistmico . ainda  controverso se a idade mais elevada  isoladamente um fator de risco para a 
 ocorrncia de cpos ou se a gravidade e a quantidade de comorbidades 
 que acometem doentes mais velhos so as responsveis por elas . nossa prevalncia de comorbidades foi 
 semelhante ou menor quando comparada a de outras publicaese 
 similar entre os grupos com e sem cpos . o inverso ocorreu com a presena de dpoc e a 
 extenso da resseco , que so , reconhecidamente , os dois mais importantes fatores de 
 risco relacionados a cpos . a primeira delas foi seu carter 
 retrospectivo ; por isso , priorizamos coletar as complicaes de maior impacto , com 
 definies previamente estabelecidas e j anteriormente utilizadas em outras 
 pesquisas em nosso servio , como infeco pulmonar , insuficincia respiratria aguda 
 e fstula broncopleural . a segunda limitao foi o modesto nmero de pacientes 
 estudados , o que comprometeu anlises estatsticas mais complexas . a terceira 
 limitao foi a possibilidade de pacientes graves no terem sido encaminhados para o 
 nosso ambulatrio por terem sido previamente considerados de muito alto risco . concluindo , a utilizao do algoritmo da accp proporcionou a identificao de um 
 grupo de pacientes cujas taxas de morbidade e mortalidade foram consideravelmente 
 mais elevadas , consumindo mais ateno em todo perodo perioperatrio . a maioria da 
 nossa populao foi avaliada apenas por espirometria , apresentando taxas de morbidade 
 e mortalidade aceitveis , mas o tecp teve um importante papel no reconhecimento do 
 paciente com alto risco . concordante com estudos publicados , idade mais avanada , 
 presena da dpoc , resseco de um ou mais lobos e funo pulmonar mais comprometida 
 estiveram relacionados  ocorrncia de cpos .
objective : to determine morbidity and mortality rates by risk category in accordance with 
 the american college of chest physicians guidelines , to determine what role 
 pulmonary function tests play in this categorization process , and to identify risk 
 factors for perioperative complications ( pcs).methods : this was a historical cohort study based on preoperative and postoperative data 
 collected for cases of lung cancer diagnosed or suspected between 2001 and 2010 . 
 results : of the 239 patients evaluated , only 13 ( 5.4% ) were classified as being at high 
 risk of pcs . predicted postoperative fev1 ( fev1ppo ) was 
 sufficient to define the risk level in 156 patients ( 65.3% ) ; however , 
 cardiopulmonary exercise testing ( cpet ) was necessary for identifying those at 
 high risk . 
 lung resection was performed in 145 patients . 
 overall morbidity and 
 mortality rates were similar to those reported in other studies . however , 
 morbidity and mortality rates for patients at an acceptable risk of pcs were 31.6% 
 and 4.3% , respectively , whereas those for patients at high risk were 83.3% and 
 33.3% . 
 advanced age , copd , lobe resection , and lower fev1ppo were 
 correlated with pcs.conclusions:although spirometry was sufficient for risk assessment in the majority of the 
 population studied , cpet played a key role in the identification of high - risk 
 patients , among whom the mortality rate was seven times higher than was that 
 observed for those at an acceptable risk of pcs . 
 the risk factors related to pcs 
 coincided with those reported in previous studies .