Trends in Lung Surgery

Increased reporting but decreased mortality associated with adverse events in patients undergoing lung cancer surgery: Competing forces in an era of heightened focus on care quality?

INTRODUCTION

Advances in surgical techniques have improved clinical outcomes and decreased complications. At the same time, heightened attention to care quality has resulted in increased identification of hospital-acquired adverse events. We evaluated these divergent effects on the reported safety of lung cancer resection.

METHODS AND MATERIALS

We analyzed hospital-acquired adverse events in patients undergoing lung cancer resection using the National Hospital Discharge Survey (NHDS) database from 2001-2010. Demographics, diagnoses, and procedures data were abstracted using ICD-9 codes. We used the Agency for Healthcare Research and Quality (AHRQ) Patient Safety Indicators (PSI) to identify hospital-acquired adverse events. Weighted analyses were performed using t-tests and chi-square.

RESULTS

A total of 302,444 hospitalizations for lung cancer resection and were included in the analysis. Incidence of PSI increased over time (28% in 2001-2002 vs 34% in 2009-2010; P<0.001). Those with one or more PSI had increased in-hospital mortality (aOR = 11.1; 95% CI, 4.7-26.1; P<0.001) and prolonged hospitalization (12.5 vs 7.8 days; P<0.001). However, among those with PSI, in-hospital mortality decreased over time, from 17% in 2001-2002 to 2% in 2009-2010.

CONCLUSIONS

In a recent ten-year period, documented rates of adverse events associated with lung cancer resection increased. Despite this increase in safety events, we observed that mortality decreased. Because such metrics may be incorporated into hospital rankings and reimbursement considerations, adverse event coding consistency and content merit further evaluation.

Increasing Numbers and Reported Adverse Events in Patients with Lung Cancer Undergoing Inpatient Lung Biopsies: A Population-Based Analysis

INTRODUCTION

The use of molecular biomarkers to guide lung cancer management has led to increasing frequency and amounts of tissue required for repeat lung biopsies. While patient safety and reporting of adverse events has been increasingly emphasized in recent decades, the safety of lung biopsies in patients with lung cancer has only been studied in small cohorts. We therefore analyzed adverse events in patients with lung cancer undergoing lung biopsies in the National Hospital Discharge Survey (NHDS) database.

METHODS

Data were abstracted using ICD-9 lung cancer diagnosis (162.X) and lung biopsy procedure codes (33.20, 33.24, 33.25, 33.26, 33.27, 33.28) from 2001 to 2010. Agency for Healthcare Research and Quality (AHRQ) Patient-Safety Indicators (PSI) were used to identify hospital-acquired adverse events. Weighted analyses were performed using SAS version 9.4.

RESULTS

A total of 540,747 patients were included for analysis. The number of biopsies increased over time, from 51,221 in 2001, to 63,239 in 2010 (P < 0.001). Overall, 159,683 (30%) patients suffered ≥ 1-PSI event during their hospitalization. Incidence of PSI varied by biopsy type: bronchoscopic (26%), percutaneous (34%), surgical (39%). The proportion of patients with ≥ 1 PSI event increased from 24% in 2001 to 38% in 2010 (P < 0.001). Patients with ≥ 1 PSI had longer length of stay (mean, 11.6 vs 8.1 days; P < 0.001) and higher in-hospital mortality (adjusted odds ratio, 5.9, 95% CI 3.9-8.9; P < 0.001).

CONCLUSIONS

The frequency of lung biopsies performed and rate of documented adverse events in hospitalized lung cancer patients have increased. These findings have policy, funding, research, and practice implications.

Extravascular lung water monitoring for thoracic and lung transplant surgeries

PURPOSE OF REVIEW

Excessive accumulation of extravascular lung water (EVLW) resulting in pulmonary edema is the most feared complication following thoracic surgery and lung transplant. ICUs have long relied on chest radiography to monitor pulmonary status postoperatively but the increasing recognition of the limitations of bedside plain films has fueled development of newer technologies, which offer earlier detection, quantitative assessments, and can aide in preoperative screening of surgical candidates. In this review, we focus on the emergence of transpulmonary thermodilution (TPTD) and lung ultrasound with a focus on the clinical integration of these modalities into current intraoperative and critical care practices.

RECENT FINDINGS

Recent studies demonstrate transpulmonary thermodilution and lung ultrasound provide greater sensitivity and earlier detection of lung water accumulation and are useful to guide clinical management. Assessments from these techniques have predictive value of postoperative outcome. Further, EVLW assessment shows promise as a preoperative screening tool in lung transplant patients.

SUMMARY

Monitoring EVLW in the perioperative period offers clinicians a powerful tool to guide fluid therapy and manage pulmonary edema. Both TPTD and lung ultrasound have unique attributes in the care of thoracic surgery and lung transplant patients.

Early nasal high-flow versus Venturi mask oxygen therapy after lung resection: a randomized trial

Background

Data on high-flow nasal oxygen after thoracic surgery are limited and confined to the comparison with low-flow oxygen. Different from low-flow oxygen, Venturi masks provide higher gas flow at a predetermined fraction of inspired oxygen (FiO₂). We conducted a randomized trial to determine whether preemptive high-flow nasal oxygen reduces the incidence of postoperative hypoxemia after lung resection, as compared to Venturi mask oxygen therapy.

Methods

In this single-center, randomized trial conducted in a teaching hospital in Italy, consecutive adult patients undergoing thoracotomic lung resection, who were not on long-term oxygen therapy, were randomly assigned to receive high-flow nasal or Venturi mask oxygen after extubation continuously for two postoperative days. The primary outcome was the incidence of postoperative hypoxemia (i.e., ratio of the partial pressure of arterial oxygen to FiO₂ (PaO₂/FiO₂) lower than 300 mmHg) within four postoperative days.

Results

Between September 2015 and April 2018, 96 patients were enrolled; 95 patients were analyzed (47 in high-flow group and 48 in Venturi mask group). In both groups, 38 patients (81% in the high-flow group and 79% in the Venturi mask group) developed postoperative hypoxemia, with an unadjusted odds ratio (OR) for the high-flow group of 1.11 [95% confidence interval (CI) 0.41–3] (p = 0.84). No inter-group differences were found in the degree of dyspnea nor in the proportion of patients needing oxygen therapy after treatment discontinuation (OR 1.34 [95% CI 0.60–3]), experiencing pulmonary complications (OR 1.29 [95% CI 0.51–3.25]) or requiring ventilatory support (OR 0.67 [95% CI 0.11–4.18]). Post hoc analyses revealed that PaO₂/FiO₂ during the study was not different between groups (p = 0.92), but patients receiving high-flow nasal oxygen had lower arterial pressure of carbon dioxide, with a mean inter-group difference of 2 mmHg [95% CI 0.5–3.4] (p = 0.009), and were burdened by a lower risk of postoperative hypercapnia (adjusted OR 0.18 [95% CI 0.06–0.54], p = 0.002).

Conclusions

When compared to Venturi mask after thoracotomic lung resection, preemptive high-flow nasal oxygen did not reduce the incidence of postoperative hypoxemia nor improved other analyzed outcomes. Further adequately powered investigations in this setting are warranted to establish whether high-flow nasal oxygen may yield clinical benefit on carbon dioxide clearance.

Trial registration

ClinicalTrials.gov, NCT02544477. Registered 9 September 2015.

Electronic supplementary material

The online version of this article (10.1186/s13054-019-2361-5) contains supplementary material, which is available to authorized users.

Incidental nonneoplastic parenchymal findings in patients undergoing lung resection for mass lesions

The prevalence of incidental nonneoplastic lung disease in patients undergoing resection for mass lesions is unknown. We determined the prevalence and characteristics of parenchymal findings in patients with lung nodules, aiming to increase awareness of findings that could potentially impact patient management. A total of 397 patients with benign or malignant mass lesions with available presurgical chest computed tomography scans resected between January 2001 and July 2015 were included. Retrospective histologic assessment of parenchymal abnormalities in at least 1 section of grossly normal lung was performed for each case by 2 pulmonary pathologists and correlated with original pathology reports, clinical history, and radiologic findings. A total of 233 women and 164 men underwent resections for carcinomas (78%) or benign nodules (22%). One hundred one (25%) patients showed parenchymal abnormalities, including 14 patients with multiple findings. The most common abnormal findings were fibrotic interstitial changes (10%), including usual interstitial pneumonia (1%), followed by granulomatous processes (8%). Other findings included aspiration (4%), intravascular thrombi (2%), Langerhans cell histiocytosis (1.5%), constrictive bronchiolitis (1%), atypical lymphoid infiltrates (1%), and amyloidosis (0.5%). Abnormalities were more likely to have been documented in the original pathology report by pulmonary pathologists (68%) than by general pathologists (15%) (P < .0001). Cases with histologic parenchymal abnormalities were more likely to show radiologic interstitial lung abnormalities than those without (16% versus 5%; P = .001). Evaluation of background lung parenchyma may yield valuable and unanticipated information in patients undergoing surgical resections for lung masses that may correlate with radiographic interstitial lung abnormalities and influence clinical management.

Enhanced recovery pathways in thoracic surgery: the Shanghai experience

The attempts to implement the enhanced recovery (ER) program based on multiple specialties to minimize errors and complications in addition to speeding up the patient's treatment and recovery as much as possible. In China mainland, there is no unified hospital system and there are large differences between hospitals' results and protocols. The patient length of stay rate at the Shanghai Pulmonary Hospital (very high-volume referral hospital) is 7 days and may be considered a very good result compared to international rates. Perhaps thanks to these results may be due to our belief in the importance of minimally invasive approaches, and their positive effects on the patients and conduct as routinely as possible, in addition to starting to build our ER protocols. The patient should be involved in this program since his first visit to the clinic until the day he left the hospital after undergoing the operation.

Current Trends of Lung Cancer Surgery and Demographic and Social Factors Related to Changes in the Trends of Lung Cancer Surgery: An Analysis of the National Database from 2010 to 2014

PURPOSE

We investigated current trends in lung cancer surgery and identified demographic and social factors related to changes in these trends.

MATERIALS AND METHODS

We estimated the incidence of lung cancer surgery using a procedure code-based approach provided by the Health Insurance Review and Assessment Service (http://opendata.hira.or.kr). The population data were obtained every year from 2010 to 2014 from the Korean Statistical Information Service (http://kosis.kr/). The annual percent change (APC) and statistical significance were calculated using the Joinpoint software.

RESULTS

From January 2010 to December 2014, 25,687 patients underwent 25,921 lung cancer surgeries, which increased by 45.1% from 2010 to 2014. The crude incidence rate of lung cancer surgery in each year increased significantly (APC, 9.5; p < 0.05). The male-to-female ratio decreased from 2.1 to 1.6 (APC, -6.3; p < 0.05). The incidence increased in the age group of ≥ 70 years for both sexes (male: APC, 3.7; p < 0.05; female: APC, 5.96; p < 0.05). Furthermore, the proportion of female patients aged ≥ 65 years increased (APC, 7.2; p < 0.05), while that of male patients aged < 65 years decreased (APC, -3.9; p < 0.05). The proportions of segmentectomies (APC, 17.8; p < 0.05) and lobectomies (APC, 7.5; p < 0.05) increased, while the proportion of pneumonectomies decreased (APC, -6.3; p < 0.05). Finally, the proportion of patients undergoing surgery in Seoul increased (APC, 1.1; p < 0.05), while the proportion in other areas decreased (APC, -1.5; p < 0.05).

CONCLUSION

An increase in the use of lung cancer surgery in elderly patients and female patients, and a decrease in the proportion of patients requiring extensive pulmonary resection were identified. Furthermore, centralization of lung cancer surgery was noted.

Surgical resection and long-term survival outcome for non-small cell lung cancer: a comparison of Victorian population-based studies spanning a decade

AIM

A survey of management of lung cancer diagnosed in Victoria in 2003 was commissioned by the Victorian Cooperative Oncology Group to identify gaps in the management of this disease. Results from a similar survey in 1993 were available to identify differences in the disease, management and outcomes. This paper details results of the surgically managed subset within the larger study.

METHODS

All patients diagnosed with lung cancer in the first 6 months of 2003 were identified from the Victorian Cancer Registry. Registry research staff completed a detailed questionnaire using primary source documents from hospitals and consulting rooms. The survey data were then de-identified with respect to patient and treating clinician prior to statistical analysis by the investigators.

RESULTS

From eligible cases identified, non-small cell lung cancer was confirmed in 655 cases with a minimum of 6 years of follow-up. Thoracotomy was performed in 145 cases (22%), but only 130 received the intended resection. Compared with 1993, significant differences were increased use of preoperative positron emission tomography (PET) scanning (79% vs 0%), relatively fewer resections (20% vs 25%), lower pneumonectomy rate (14% vs 25%) and higher sub-lobar resection rate (22% vs 11%). The 30-day mortality remained below 2%. Positive resection margin (21%) and abandoned resection rates (10%) were much higher than expected. Overall 5-year survival was 42%, unchanged from 1993.

CONCLUSION

Irrespective of widespread introduction of PET scanning, thoracotomy without resection was common. While operative mortality and overall survival were well within benchmark standards, futile thoracotomy and positive resection margin rates were unacceptably high.

Morbidity, mortality and survival after 110 consecutive bilobectomies over 12 years

OBJECTIVES

To analyse statistical aspects of mortality, morbidity and survival after bilobectomy (BT), an operation rarely studied in the literature.

METHODS

One hundred and ten cases were studied, comprising 58 upper-middle bilobectomies and 52 lower-middle bilobectomies performed between 1999 and 2010. Indications were of 9 benign diseases, 12 carcinoid tumours, 5 metastases and 84 non-small cell lung cancers (2 stage 0; 34 stage I; 22 stage II; 25 stage III and 1 stage IV).

RESULTS

Mortality was nil. Twenty-six percent of patients experienced significant morbidity, influenced in multivariate analysis by the presence of three or more comorbidities (P = 0.03) and by a forced expiratory volume in 1 s of <60% (P = 0.01). Lower-middle BT was associated with more postoperative complications than upper-middle BT (P = 0.012). The 5-year survival rate of patients with non-small cell lung carcinoma was 82% in stage I, 59% in stage II and 20% in stage IIIA. Survival was significantly influenced by stage (P = 0.0018) and tobacco weaning (P = 0.0012).

CONCLUSIONS

BT can be achieved with low mortality, and survival results that are comparable with those unregistered after standard lobectomy. However, almost one quarter of patients experienced significant postoperative complications. Surgical techniques aiming to reduce residual pleural space should be especially considered after lower-middle BT, due to the highest morbidity being associated with this procedure.

Lobectomy for patients with limited lung function

Increasingly, lung cancer is being diagnosed at an early stage. This trend is likely to increase with computerized tomographic screening as a result of the findings of the National Lung Screening Trial. Even in 2011, anatomical lobectomy is the gold standard for curative resection for early lung cancer. However, a significant proportion of patients with early lung cancer have limited lung function that places them at higher risk of complications from lobectomy. This article reviews the existing data for lobectomy in patients with limited lung function.

Selective Neurogenic Blockade and Perioperative Immune Reactivity in Patients Undergoing Lung Resection

OBJECTIVE: This double-blind, prospective, randomized, controlled trial examined the effects of thoracic epidural block and intravenous clonidine and opioid treatment on the postoperative Th1/Th2 cytokine ratio after lung surgery. The primary endpoint was the interferon γ (IFN-γ; Th1 cytokine)/interleukin 4 (IL-4; Th2 cytokine) ratio. Secondary endpoints were reductions in pain and incidence of pneumonia. METHODS: Sixty patients were randomized into three groups to receive remifentanil intravenously (remifentanil group, n = 20), remifentanil and clonidine intravenously (clonidine group, n = 20), or ropivacaine epidurally (ropivacaine group, n = 20). Pain was assessed using a numerical rating scale (NRS). Cytokines were measured using a cytometric bead array. RESULTS: Patients in the ropivacaine group (thoracic epidural block) had a significantly lower IFN-γ/IL-4 ratio at the end of surgery than those in the remifentanil group and clonidine group. There were no significant between-group differences in the IFN-γ/IL-4 ratio at other time-points. There were no differences in NRS scores at any time-point. No patient developed pneumonia. CONCLUSION: Intraoperative thoracic epidural block decreased the IFN-γ/IL-4 ratio immediately after lung surgery, indicating less inflammatory stimulation during surgery.

The effect of regionalization on outcome in pulmonary lobectomy: a Canadian national study

Objective

To examine the effect of regionalization of thoracic surgery services in Canada by evaluating change over time in hospital volumes of pulmonary lobectomy and its impact on length of stay and in-hospital mortality.

Methods

Data on pulmonary lobectomy between 1999 and 2007 were abstracted from the Canadian Institute for Health Information Discharge Abstract Database. In-hospital mortality was analyzed by logistic regression, and log-transformed length of stay was analyzed by linear regression. Cross-sectional analysis of hospital volume, in-hospital mortality, and length of stay was performed, controlling for clustering. Within-hospital changes in annual volume on outcome was analyzed using multivariable logistic regression, controlling for Charlson comorbidity index and other confounders.

Results

Of 19,732 patients, 10, 281 (52%) were male, with an average age of 63.3 years. There was a 45% (95% confidence interval, 21–61; P = .001) relative risk reduction in in-hospital mortality with a 19% reduction in length of stay (95% confidence interval, 12–25; P < .0001). On comparison of volume between hospitals, an increase of 20 cases was associated with a 15% relative risk reduction (95% confidence interval, 9–19; P < .0001) in in-hospital mortality and a 5% relative decrease (95% confidence interval, 3–7; P < .001) in length of stay. Within hospitals there was a nonsignificant relationship between volume and in-hospital mortality.

Conclusions

In-hospital mortality and length of stay for lobectomies have decreased in Canada. In multivariate analysis, volume was associated with improved in-hospital mortality, but there was no reduction in mortality when volume was increased within a given hospital. However, the proportion of patients treated in high-volume centers has increased over time, inferring the importance of high-volume centers in improved outcomes. This supports regionalization policies for pulmonary lobectomy.

Health care utilization among surgically treated Medicare beneficiaries with lung cancer

BACKGROUND

Markers of increased health care utilization are surrogates for adverse events, and one such metric--prolonged length of stay greater than 14 days (PLOS)--was recently endorsed as a provider-level performance measure.

METHODS

This is a cohort study (1992 through 2002) aimed to describe increased health care utilization among 21,067 operated lung cancer patients using the Surveillance, Epidemiology, and End-Results-Medicare database. Increased utilization was defined by PLOS, discharge to an institutional care facility (ICF), or readmission within 30 days.

RESULTS

Twelve percent of patients had a PLOS, 13% were discharged to an ICF, and 15% were readmitted. In multivariate analyses, factors associated with a higher odds ratio of PLOS, discharge to ICF, or readmission included age older than 80 years, increasing comorbidity index, not being married, and pneumonectomy (all p < 0.05). Relative to patients living in the West, those in the Midwest or South had a higher odds ratio of PLOS and readmission but a lower odds ratio of discharge to an ICF (all p < 0.05). Adjusted rates of PLOS decreased significantly with time, whereas adjusted ICF and readmission rates increased (all p < 0.01). Patients who required increased utilization had higher adjusted 2.5-year mortality rates compared with those who did not (PLOS, 42% versus 20%; ICF, 32% versus 20%; readmission, 33% versus 19%; all p < 0.001).

CONCLUSIONS

Baseline health status and nonclinical factors were associated with increased utilization, nonuniform trends in utilization were observed with time, and increased utilization was associated with worse long-term outcomes. These findings have implications for quality-improvement initiatives that measure increased health care utilization as a surrogate for provider performance.

Trends in demographics, comorbidity profiles, in-hospital complications and mortality associated with primary knee arthroplasty

We analyzed the National Hospital Discharge Survey to elucidate temporal changes in the demographics, comorbidities, hospital stay, in-hospital complications, and mortality of patients undergoing primary total knee arthroplasties (TKAs) in the United States. Three 5-year periods were created (1990-1994, 1995-1999, and 2000-2004), and temporal changes were analyzed. The number of TKAs performed increased by 125% for the 3 periods. The increasing proportion of younger patients was accompanied by a concomitant decrease of Medicare-insured patients. Length of stay decreased from 8.44 to 4.18 days. An increase in the proportion of discharges to long-term and short-term care facilities and in procedures performed in small hospitals was noted. Although the prevalence of procedure-related complications decreased over time, comorbidities increased. Despite a decrease in mortality from the first to the second study period (0.50% vs 0.21%), a slight increase was noticed more recently (0.28%). We identified significant changes in most variables studied.

Acute lung injury and outcomes after thoracic surgery

PURPOSE OF REVIEW

The present review evaluates the evidence available in the literature tracking perioperative mortality and morbidity as well as the pathogenesis and management of acute lung injury (ALI) in patients undergoing thoracotomy.

RECENT FINDINGS

Over the last decade, despite increasing age and comorbid conditions, the operative mortality has remained unchanged for patients undergoing lung resection, whereas procedure-related complications have declined. Better clinical outcomes are achieved in high-volume hospitals and when procedures are performed by a thoracic surgeon. Postthoracotomy ALI has become the leading cause of operative death, its incidence has remained stable (2-5%) and earlier diagnosis can be made by assessing the extravascular lung water volume with the single-indicator dilution technique. The pathogenesis of ALI implicates a multiple-hit sequence of various triggering factors (e.g. oxidative stress and surgical-induced inflammation) in addition to injurious ventilatory settings and genetic predisposition.

SUMMARY

Knowledge of the perioperative risk factors of major complications and understanding of the mechanisms of postthoracotomy ALI enable anesthesiologists to implement 'protective' lung strategies including the use of low tidal volume (VT) with recruitment maneuvers, a goal-directed fluid approach and prophylactic treatment with inhaled beta2-adrenergic agonists.

Postoperative care after pulmonary resection: postanesthesia care unit versus intensive care unit

PURPOSE OF REVIEW

In an effort to maximize resource utilization and contain costs, immediate postoperative care after noncardiac thoracic surgery is often done in either the postanesthesia care unit or dedicated step down units, leaving the ICU for complex surgical cases, overtly high-risk patients, or the treatment of severe postoperative complications. This review analyzes the current modalities affecting length of stay and costs, mainly by allocating patients after elective lung resection to different postoperative areas according to their needs.

RECENT FINDINGS

Several surgical models have been published in recent years with the goal of optimizing perioperative patient care and subsequently decreasing hospital costs and length of stay. The main focus has been on elective lung resection for lung cancer. Preoperative evaluation, changes in surgical and anesthetic techniques as well as careful planning on where to recover these patients seem to make a clinical and financial impact.

SUMMARY

The development of models to help predict elective ICU admission should facilitate optimal care, cutting costs and shortening length of stay after lung resection.

Impact of intraoperative lung-protective interventions in patients undergoing lung cancer surgery

Introduction

In lung cancer surgery, large tidal volume and elevated inspiratory pressure are known risk factors of acute lung (ALI). Mechanical ventilation with low tidal volume has been shown to attenuate lung injuries in critically ill patients. In the current study, we assessed the impact of a protective lung ventilation (PLV) protocol in patients undergoing lung cancer resection.

Methods

We performed a secondary analysis of an observational cohort. Demographic, surgical, clinical and outcome data were prospectively collected over a 10-year period. The PLV protocol consisted of small tidal volume, limiting maximal pressure ventilation and adding end-expiratory positive pressure along with recruitment maneuvers. Multivariate analysis with logistic regression was performed and data were compared before and after implementation of the PLV protocol: from 1998 to 2003 (historical group, n = 533) and from 2003 to 2008 (protocol group, n = 558).

Results

Baseline patient characteristics were similar in the two cohorts, except for a higher cardiovascular risk profile in the intervention group. During one-lung ventilation, protocol-managed patients had lower tidal volume (5.3 ± 1.1 vs. 7.1 ± 1.2 ml/kg in historical controls, P = 0.013) and higher dynamic compliance (45 ± 8 vs. 32 ± 7 ml/cmH₂O, P = 0.011). After implementing PLV, there was a decreased incidence of acute lung injury (from 3.7% to 0.9%, P < 0.01) and atelectasis (from 8.8 to 5.0, P = 0.018), fewer admissions to the intensive care unit (from 9.4% vs. 2.5%, P < 0.001) and shorter hospital stay (from 14.5 ± 3.3 vs. 11.8 ± 4.1, P < 0.01). When adjusted for baseline characteristics, implementation of the open-lung protocol was associated with a reduced risk of acute lung injury (adjusted odds ratio of 0.34 with 95% confidence interval of 0.23 to 0.75; P = 0.002).

Conclusions

Implementing an intraoperative PLV protocol in patients undergoing lung cancer resection was associated with improved postoperative respiratory outcomes as evidence by significantly reduced incidences of acute lung injury and atelectasis along with reduced utilization of intensive care unit resources.

Future trends in preoperative evaluation

Preoperative evaluation before lung resection has been frequently addressed in modern medical literature. Actual or predicted pulmonary volumes are considered relevant to predict the risk of surgery. Nevertheless, ppoFEV1 underestimates the real functional loss in the immediate postoperative period when most of the complications occur. Not all patients, however, have comparable functional changes after lobectomy. Minimal impairment or even improvements have been demonstrated in COPD cases after lobectomy. Efforts should be directed to an accurate prediction of the immediate postoperative pulmonary volumes for a better evaluation of high-risk patients caused by respiratory impairment. Future developments are needed on the role of measuring preoperative DLCO and how to evaluate a patient's general cardiorespiratory status. Evidence underlines the relevance of routine evaluation of preoperative DLCO at rest or, better, during exercise for a thorough assessment of patient's capability to adapt to a stressful situation (Fig. 3). Only by improving knowledge about the general condition of the patient, can one assess the physiologic response to surgery. Widespread use of sophisticated or simple exercise tests and measurements or daily activity using motion detectors can identify high-risk patients with otherwise acceptable pulmonary volumes. Another suggested investigation issue is to develop different relevant outcome parameters, not only from the surgeon's point of view but also from the patient's perspective, such as postoperative QOL-related variables or delayed outcomes. Finally, multidisciplinary investigation teams, including experts in mathematical modeling, are essential to improve the quality and validity of the developed models. Although knowledge about perioperative physiologic changes has increased, clinicians are still far from finding a way to put all this knowledge down and make it applicable for an individual patient. Multicentric cooperation and evaluation of large prospectively recorded databases are essential to develop evidence-based clinical guidelines on preoperative evaluation.