Lung Resection Candidates Research Articles

Walking or breathing: comparing the 6-minute walking distance test to the pulmonary function test for lung resection candidates.

Given the limited use of the 6-minute walking distance (6MWD) test as a replacement for standard tests in thoracic surgery, insufficient research exists on the prognostic value of this test, and further studies are necessary. This study aimed to investigate the correlation between pulmonary function tests (PFT) and the 6MWD test in lung resection patients. This cross-sectional study, conducted in 2021-2022, involved lung resection candidates referred to the thoracic surgery clinic. Demographic data, including age, sex, and body mass index (BMI), were collected, and pulmonary function tests and 6MWD tests were conducted for all patients. The sample size of the study was 31, and all patients received routine treatment during hospitalization. Of the 31 subjects included in the study, 16 were male (51.6%) and 15 (48.4%) were female. The mean age of the patients was 33.45±13.78 years. The median forced expiratory volume in one second (FEV1) and the mean ratio of FEV1/forced vital capacity (FVC) were 2.16 (1.49-2.85) liters and 81.80±7.34%, respectively. No significant correlation was found between the results of 6MWD and PFT, including FVC, FEV1, and FEV1/FVC ratio (P>0.05). The 6MWD test is a more economical and easily accessible test than PFT. However, this study found no correlation between the 6MWD test and spirometry parameters. Therefore, we suggest that surgeons should not rely on the 6MWD test as a predictive value for assessing respiratory function in lung resection candidates. The study's findings have important implications for clinical practice.

New models for prediction of postoperative pulmonary complications in lung resection candidates.

In recent years, ventilatory efficiency (minute ventilation (V'E)/carbon dioxide production (V'CO2 ) slope) and partial pressure of end-tidal carbon dioxide (P ETCO2 ) have emerged as independent predictors of postoperative pulmonary complications (PPC). Single parameters may give only partial information regarding periprocedural hazards. Accordingly, our aim was to create prediction models with improved ability to stratify PPC risk in patients scheduled for elective lung resection surgery. This post hoc analysis was comprised of consecutive lung resection candidates from two prior prospective trials. All individuals completed pulmonary function tests and cardiopulmonary exercise testing (CPET). Logistic regression analyses were used for identification of risk factors for PPC that were entered into the final risk prediction models. Two risk models were developed; the first used rest P ETCO2 (for patients with no available CPET data), the second used V'E/ V'CO2 slope (for patients with available CPET data). Receiver operating characteristic analysis with the De-Long test and area under the curve (AUC) were used for comparison of models. The dataset from 423 patients was randomly split into the derivation (n=310) and validation (n=113) cohorts. Two final models were developed, both including sex, thoracotomy, "atypical" resection and forced expiratory volume in 1 s/forced vital capacity ratio as risk factors. In addition, the first model also included rest P ETCO2 , while the second model used V'E/V'CO2 slope from CPET. AUCs of risk scores were 0.795 (95% CI: 0.739-0.851) and 0.793 (95% CI: 0.737-0.849); both p<0.001. No differences in AUCs were found between the derivation and validation cohorts. We created two multicomponental models for PPC risk prediction, both having excellent predictive properties.

Development of Machine Learning Model for VO2max Estimation Using a Patch-Type Single-Lead ECG Monitoring Device in Lung Resection Candidates.

A cardiopulmonary exercise test (CPET) is essential for lung resection. However, performing a CPET can be challenging. This study aimed to develop a machine learning model to estimate maximal oxygen consumption (VO2max) using data collected through a patch-type single-lead electrocardiogram (ECG) monitoring device in candidates for lung resection. This prospective, single-center study included 42 patients who underwent a CPET at a tertiary teaching hospital from October 2021 to July 2022. During the CPET, a single-lead ECG monitoring device was applied to all patients, and the results obtained from the machine-learning algorithm using the information extracted from the ECG patch were compared with the CPET results. According to the Bland-Altman plot of measured and estimated VO2max, the VO2max values obtained from the machine learning model and the FRIEND equation showed lower differences from the reference value (bias: -0.33 mL·kg-1·min-1, bias: 0.30 mL·kg-1·min-1, respectively). In subgroup analysis, the developed model demonstrated greater consistency when applied to different maximal stage levels and sexes. In conclusion, our model provides a closer estimation of VO2max values measured using a CPET than existing equations. This model may be a promising tool for estimating VO2max and assessing cardiopulmonary reserve in lung resection candidates when a CPET is not feasible.

3D-Quantitated Single Photon Emission Computed Tomography/Computed Tomography: Impact on intended Management Compared to Lung Perfusion Scan in Marginal Candidates for Pulmonary Resection

ObjectivesBased on previous studies, single-photon emission computed tomography/computed tomography (SPECT/CT) has been proven more accurate and reproducible than planar lung perfusion scintigraphy to assess lobar perfusion. However, the impact of 3D-quantitated SPECT/CT on intended management in functionally marginal candidates for pulmonary resection is unknown. The evaluation of this impact was the main aim of this study. MethodsConsecutive candidates for lung resection underwent preoperative evaluation according to ERS/ESTS Algorithm and underwent preoperative lung perfusion imaging. The lobar contribution to the total lung perfusion was estimated using established planar scintigraphic methods and 3-dimensional quantitative SPECT/CT method (CT Pulmo3D and xSPECT-Quant, Siemens). The difference in estimated lobar perfusion with resulting changes in predicted postoperative (ppo) lung function and extent of lung resection were analyzed to reveal possible changes in operability. In-hospital outcome was assessed. ResultsOne hundred twenty patients (46 females) were enrolled. The mean age (±SD) of patients was 68 ± 9 years, target lesions were in upper lobes in 57.7% and in lower lobes in 33.5%. The median FEV1 (forced expiratory volume in 1 second) was 70.5% (IQR 52-84) and median DLCO (diffusion capacity of lung for carbon monoxide) was 56.6% [47.1-67.4]. The planar posterior oblique method, compared to 3D-quantitated SPECT/CT, underestimated the perfusion of upper lobes by a median difference of 5% (right [2-9], left [2.5-8]; P = <.0001), while it overestimated the perfusion of lower lobes (left by 4% [2-7], right by 6% [2-9]; P = <.0001). In contrast to planar scintigraphy-based evaluation, 4 patients (3.3%), all with upper lobe lesions, were classified as inoperable when 3D-quantitated SPECT/CT was used for calculation of the ppo lung function. ConclusionsIn selected patients with upper lobe lesions, 3D-quantitated SPECT/CT would have changed the treatment strategy from operable to inoperable. Importantly, postoperative mortality in this particular subgroup was disproportionally high. 3D-quantitated SPECT/CT shall be further evaluated as it might improve preoperative risk stratification in functionally marginal candidates.

The risk of post-operative pulmonary complications in lung resection candidates with normal forced expiratory volume in 1 s and diffusing capacity of the lung for carbon monoxide: a prospective multicentre study.

According to the guidelines for preoperative assessment of lung resection candidates, patients with normal forced expiratory volume in 1 s (FEV1) and diffusing capacity of the lung for carbon monoxide (D LCO) are at low risk for post-operative pulmonary complications (PPC). However, PPC affect hospital length of stay and related healthcare costs. We aimed to assess risk of PPC for lung resection candidates with normal FEV1 and D LCO (>80% predicted) and identify factors associated with PPC. 398 patients were prospectively studied at two centres between 2017 and 2021. PPC were recorded from the first 30 post-operative days. Subgroups of patients with and without PPC were compared and factors with significant difference were analysed by uni- and multivariate logistic regression. 188 subjects had normal FEV1 and D LCO. Of these, 17 patients (9%) developed PPC. Patients with PPC had significantly lower pressure of end-tidal carbon dioxide (P ETCO2 ) at rest (27.7 versus 29.9; p=0.033) and higher ventilatory efficiency (V'E/V'CO2 ) slope (31.1 versus 28; p=0.016) compared to those without PPC. Multivariate models showed association between resting P ETCO2 (OR 0.872; p=0.035) and V'E/V'CO2 slope (OR 1.116; p=0.03) and PPC. In both models, thoracotomy was strongly associated with PPC (OR 6.419; p=0.005 and OR 5.884; p=0.007, respectively). Peak oxygen consumption failed to predict PPC (p=0.917). Resting P ETCO2 adds incremental information for risk prediction of PPC in patients with normal FEV1 and D LCO. We propose resting P ETCO2 be an additional parameter to FEV1 and D LCO for preoperative risk stratification.

Ventilatory efficiency is superior to peak oxygen uptake for prediction of lung resection cardiovascular complications.

Ventilatory efficiency (VE/VCO2 slope) has been shown superior to peak oxygen consumption (VO2) for prediction of post-operative pulmonary complications in patients undergoing thoracotomy. VE/VCO2 slope is determined by ventilatory drive and ventilation/perfusion mismatch whereas VO2 is related to cardiac output and arteriovenous oxygen difference. We hypothesized pre-operative VO2 predicts post-operative cardiovascular complications in patients undergoing lung resection. Lung resection candidates from a published study were evaluated by post-hoc analysis. All of the patients underwent preoperative cardiopulmonary exercise testing. Post-operative cardiovascular complications were assessed during the first 30 post-operative days or hospital stay. One-way analysis of variance or the Kruskal-Wallis test, and multivariate logistic regression were used for statistical analysis and data summarized as median (IQR). Of 353 subjects, 30 (9%) developed pulmonary complications only (excluded from further analysis), while 78 subjects (22%) developed cardiovascular complications and were divided into two groups for analysis: cardiovascular only (n = 49) and cardiovascular with pulmonary complications (n = 29). Compared to patients without complications (n = 245), peak VO2 was significantly lower in the cardiovascular with pulmonary complications group [19.9 ml/kg/min (16.5-25) vs. 16.3 ml/kg/min (15-20.3); P<0.01] but not in the cardiovascular only complications group [19.9 ml/kg/min (16.5-25) vs 19.0 ml/kg/min (16-23.1); P = 0.18]. In contrast, VE/VCO2 slope was significantly higher in both cardiovascular only [29 (25-33) vs. 31 (27-37); P = 0.05] and cardiovascular with pulmonary complication groups [29 (25-33) vs. 37 (34-42); P<0.01)]. Logistic regression analysis showed VE/VCO2 slope [OR = 1.06; 95%CI (1.01-1.11); P = 0.01; AUC = 0.74], but not peak VO2 to be independently associated with post-operative cardiovascular complications. VE/VCO2 slope is superior to peak VO2 for prediction of post-operative cardiovascular complications in lung resection candidates.

The effect of thoracic epidural nerve block with dezocine and ropivacaine on arterial oxygen saturation and IDO gene expression during pulmonary ventilation in lung resection surgery.

During lung resection surgery, the blood supply to the lungs increases the intrapulmonary shunt and reduces arterial oxygenation in patients. Ventilation anesthesia of a lung may affect oxygenation. The present study aimed to compare intravenous anesthesia with and without thoracic epidural block (dezocine and ropivacaine) on oxygen saturation during lung ventilation in patients undergoing lung resection surgery. For this purpose, this study was performed as a double-blind, randomized clinical trial. Sixty patients who were candidates for lung resection were divided into two intervention groups (thoracic epidural block with dezocine and ropivacaine and intravenous anesthesia) and a control group (placebo thoracic epidural block and intravenous anesthesia). Hemodynamic variables, Aldert score, and possible complications were compared between the two groups before surgery and after recovery. Also, the expression level of the IDO gene was evaluated using the real-time PCR technique. SPSS, t-test, Mann-Whitney U, Chi-square, and Fisher performed data analysis and comparison. The results showed that the changes in hemodynamic variables and PaO2, SaO2, and ETCO2 were not statistically significant between the two groups. Aldrete's score at entry and exit of recovery was similar between the two groups. During the recovery period, the percentage of pain or chills in the group under complete intravenous anesthesia was significantly higher. There was no significant difference between the two groups regarding the frequency of nausea and hypotension. Also, the results of IDO gene expression showed that general anesthesia with the thoracic epidural block (dezocine and ropivacaine), which is involved in inducing immunological tolerance and suppressing immune responses, has no significant effect. The stress of performing surgery before surgery can play a role in suppressing the patient's immunity, and anesthesia of the thoracic epidural block (dezocine and ropivacaine) has no significant effect on IDO expression. In general, thoracic epidural block with complete intravenous anesthesia has no significant effect on oxygen saturation in ventilated lungs compared with intravenous anesthesia alone. Nevertheless, this combination significantly reduces postoperative pain and chills.

3D-quantitated lung perfusion SPECT/CT: Impact on intended management compared to lung perfusion scan in marginal candidates for lung resection surgery

Abstract Objective Based on previous studies, single-photon emission computed tomography/computed tomography (SPECT/CT) has been proven to be more accurate and reproducible than planar lung perfusion scintigraphy. We conducted a study to evaluate the impact of 3D-quantitated lung perfusion SPECT/CT on intended management in candidates for lung resection surgery. Methods Retrospective study including candidates for lung resection surgery with lung perfusion imaging. Patients underwent preoperative evaluation according to ERS/ESTS algorithm. The lobar contribution to the total lung perfusion was estimated using planar antero-posterior, posterior oblique and three-dimensional anatomical SPECT/CT method (CT Pulmo 3D and xSPECT- Quant, Siemens). The difference in lobar perfusion with resulting changes in the extent of lung resection were analyzed to reveal possible changes in operability. Results 120 patients (46 females) with known lung cancer or pulmonary lesion considered for resection with available lung perfusion scintigraphy and SPECT/CT were enrolled. The mean age (±SD) of patients was 68 ±9 years, the target lesions were located in upper lobe in 57.7% and in lower lobe in 33.5%. The median [IQR] FEV1 was 70.5% [52–84] and median DLCO 56.6% [47.1–67.4]. The planar posterior oblique method, compared to 3D-quantitated SPECT/CT, underestimated the perfusion of upper lobes by a median difference of 5% (right [2–9; IQR]; left [2.5–8], p= &amp;lt; 0.0001), while it overestimated the both lower lobes (left by 4% [2–7]; right by 6% [2–9], p= &amp;lt; 0.0001). In contrast to the planar scintigraphy based evaluation, 4(3.3%) patients with upper lobe lesions were classified as inoperable when 3D-quantitated SPECT/CT was used for calculation of predicted postoperative lung function. Conclusion In selected patients with upper lobe lesions, 3D-quantitated SPECT/CT would have changed the treatment strategy from operable to inoperable. Importantly, post-operative mortality in this particular subgroup was disproportionally high. 3D-quantitated SPECT/CT shall be further evaluated as it might improve preoperative risk stratification in marginal lung resection candidates.

Prediction of Postoperative Complications: Ventilatory Efficiency and Rest End-tidal Carbon Dioxide

BackgroundCardiopulmonary exercise testing parameters including ventilatory efficiency (VE/VCO2 slope) are used for risk assessment of lung resection candidates. However, many patients are unable or unwilling to undergo exercise. VE/VCO2 slope is closely related to the partial pressure of end-tidal carbon dioxide (PETCO2). We hypothesized PETCO2 at rest predicts postoperative pulmonary complications. MethodsConsecutive lung resection candidates were included in this prospective multicenter study. Postoperative respiratory complications were assessed from the first 30 postoperative days or from the hospital stay. Student t test or Mann-Whitney U test was used for comparison. Multivariate stepwise logistic regression analysis was used to analyze association with the development of postoperative pulmonary complications. The De Long test was used to compare area under the curve (AUC). Data are summarized as median (interquartile range). ResultsThree hundred fifty-three patients were analyzed, of which 59 (17%) developed postoperative pulmonary complications. PETCO2 at rest was significantly lower (27 [24-30] vs 29 [26-32] mm Hg; P < .01) and VE/VCO2 slope during exercise significantly higher (35 [30-40] vs 29 [25-33]; P < .01) in patients who developed postoperative pulmonary complications. Both rest PETCO2 with odds ratio 0.90 (95% confidence interval [CI] 0.83-0.97); P = .01 and VE/VCO2 slope with odds ratio 1.10 (95% CI 1.05-1.16); P < .01 were independently associated with postoperative pulmonary complications by multivariate stepwise logistic regression analysis. There was no significant difference between AUC of both models (rest PETCO2: AUC = 0.79 (95% CI 0.74-0.85); VE/VCO2 slope: AUC = 0.81 (95% CI 0.75-0.86); P = .48). ConclusionsPETCO2 at rest has similar prognostic utility as VE/VCO2 slope, suggesting rest PETCO2 may be used for postoperative pulmonary complications prediction in lung resection candidates.

Morbidity and mortality of lung resection candidates defined by the American College of Chest Physicians as 'moderate risk': an analysis from the European Society of Thoracic Surgeons database.

The American College of Chest Physicians functional guidelines classify patients with predicted postoperative forced expiratory volume in 1 s or predicted postoperative carbon monoxide lung diffusion capacity <60% and with maximal oxygen consumption (VO2max) between 10 and 20 ml/kg/min in a heterogeneous category broadly defined as 'moderate risk' with variable morbidity and mortality. Data to support this statement are lacking. Using the European Society of Thoracic Surgeons database, our goal was to test this definition by evaluating the morbidity and mortality of those patients falling into this class. All patients who had anatomical lung resection for lung cancer (2007-2019) and were deemed of moderate risk were identified in the European Society of Thoracic Surgeons database. Cardiopulmonary morbidity and 30-day mortality of these patients were assessed by the type of operation. A total 2016 patients were identified. The incidence of cardiopulmonary complications in this group was 21% after lobectomy (294/1435), 29% after bilobectomy (33/112), 22% after pneumonectomy (72/333) and 16% after segmentectomy (22/136) (analysis of variance P = 0.07). The 30-day mortality was 3.4% after lobectomy (49/1435), 8.9% after bilobectomy (10/112), 7.8% after pneumonectomy (26/333) and 3.7% after segmentectomy (5/136) (analysis of variance P = 0.0005). The 30-day mortality rate was 1.6-fold higher in patients with a VO2max between 10 and 15 ml/kg/min compared to those with a higher VO2max [49/861 (5.7%) vs 41/1155 (3.5%); P = 0.022]. For operations that were less extensive than a pneumonectomy and were performed by minimally invasive surgery, there was no difference in mortality between patients with a VO2max between 10 and 15 ml/kg/min and those with a higher VO2max [7/181 (3.8%) vs 11/272 (4.0%); P = 0.92]. On the other hand, after open surgery, the mortality of patients with a lower VO2max (10-15 ml/kg/min) was higher than that of those with a higher VO2max [26/501 (5.1%) vs 20/721 (2.8%); P = 0.034]. Linear regression adjusting for the extent and access of the operation confirmed that within the moderate-risk group a VO2max <15 ml/kg/min was associated with higher mortality (P = 0.028; odds ratio 1.61; 95% confidence interval 1.1-2.5). Morbidity and mortality rates found in this study are not negligible and reinforce the recommendation to ensure careful patient discussion and informed decision-making prior to lung cancer resection surgery.

A Machine Learning Approach for Postoperative Outcome Prediction: Surgical Data Science Application in a Thoracic Surgery Setting.

The use of innovative methodologies, such as Surgical Data Science (SDS), based on artificial intelligence (AI) could prove to be useful for extracting knowledge from clinical data overcoming limitations inherent in medical registries analysis. The aim of the study is to verify if the application of an AI analysis to our database could develop a model able to predict cardiopulmonary complications in patients submitted to lung resection. We retrospectively analyzed data of patients submitted to lobectomy, bilobectomy, segmentectomy and pneumonectomy (January 2006-December 2018). Fifty preoperative characteristics were used for predicting the occurrence of cardiopulmonary complications. The prediction model was developed by training and testing a machine learning (ML) algorithm (XGBOOST) able to deal with registries characterized by missing data. We calculated the receiver operating characteristic curve, true positive rate (TPR), positive predictive value (PPV) and accuracy of the model. We analyzed 1360 patients (lobectomy: 80.7%, segmentectomy: 11.9%, bilobectomy 3.7%, pneumonectomy: 3.7%) and23.3% of them experienced cardiopulmonary complications. XGBOOST algorithm generated a model able to predict complications with an area under the curve of 0.75, a TPR of 0.76, a PPV of 0.68. The model's accuracy was 0.70. The algorithm included all the variables in the model regardlessof their completeness. Using SDS principles in thoracic surgery for the first time, we developed an ML model able to predict cardiopulmonary complications after lung resection based on 50 patient characteristics. The prediction was also possible even in the case of those patients for whom we had incomplete data. This model could improve the process of counseling and the perioperative management of lung resection candidates.

Preoperative evaluation for lung resection in patients with bronchiectasis: should we rely on standard lung function evaluation?

The scant data about non-cystic fibrosis bronchiectasis, including tuberculosis sequelae and impairment of lung function, can bias the preoperative physiological assessment. Our goal was to evaluate the changes in lung function and exercise capacity following pulmonary resection in these patients; we also looked for outcome predictors. We performed a non-randomized prospective study evaluating lung function changes in patients with non-cystic fibrosis bronchiectasis treated with pulmonary resection. Patients performed lung function tests and cardiopulmonary exercise tests preoperatively and 3 and 9 months after the operation. Demographic data, comorbidities, surgical data and complications were collected. Forty-four patients were evaluated for lung function. After resection, the patients had slightly lower values for spirometry: forced expiratory volume in 1 s preoperatively: 2.21 l ± 0.8; at 3 months: 1.9 l ± 0.8 and at 9 months: 2.0 l ± 0.8, but the relationship between the forced expiratory volume in 1 s and the forced vital capacity remained. The gas diffusion measured by diffusing capacity for carbon monoxide did not change: preoperative value: 23.2 ml/min/mmHg ± 7.4; at 3 months: 21.5 ml/min/mmHg ± 5.6; and at 9 months: 21.7 ml/min/mmHg ± 8.2. The performance of general exercise did not change; peak oxygen consumption preoperatively was 20.9 ml/kg/min ± 7.4; at 3 months: 19.3 ml/kg/min ± 6.4; and at 9 months: 20.2 ml/kg/min ± 8.0. Forty-six patients were included for analysis of complications. We had 13 complications with 2 deaths. To test the capacity of the predicted postoperative (PPO) values to forecast complications, we performed several multivariate and univariate analyses; none of them was a significant predictor of complications. When we analysed other variables, only bronchoalveolar lavage with positive culture was significant for postoperative complications (P = 0.0023). Patients who had a pneumonectomy had a longer stay in the intensive care unit (P = 0.0348). The calculated PPO forced expiratory volume in 1 s had an excellent correlation with the measurements at 3 and 9 months; but the calculated PPO capacity for carbon monoxide and the PPO peak oxygen consumption slightly underestimated the 3- and 9-month values. However, none of them was a predictor for complications. Better tools to predict postoperative complications for patients with bronchiectasis who are candidates for lung resection are needed. Clinicaltrials.gov: NCT01268475.

Preoperative Evaluation for Lung Resection Surgery

The purpose of this article is to review the literature surrounding preoperative assessment and management of patients undergoing lung resection surgery. The traditional preoperative cardiovascular risk assessment can be further refined in patients undergoing lung resection surgery with the Thoracic Revised Cardiac Risk Index and cardiac biomarkers such as B-type natriuretic peptide. Cardiorespiratory exercise testing parameters such as the maximal achieved oxygen consumption (VO2 peak) and the minute ventilation to carbon dioxide output (VE/VCO2) slope are strong preoperative prognosticators in patients with borderline lung function. Preoperative pulmonary rehabilitation holds promising benefits in improving surgical candidacy and postoperative outcomes. The preoperative assessment of lung resection candidates must evaluate perioperative cardiorespiratory risk. The patient’s comorbidities should be optimized as time permits. A clear perioperative plan should be established and may include cardiology consultation, prevention strategies for arrhythmias, preoperative pulmonary rehabilitation, smoking cessation, intensive perioperative monitoring, and enhanced recovery protocols.

The 6-min walk test in the functional evaluation of patients with lung cancer qualified for lobectomy.

The American College of Chest Physicians guidelines recommend low-technology exercise tests in the functional evaluation of patients with lung cancer considered for resectional surgery. However, the 6-min walk test (6MWT) is not included, because the data on its clinical value are inconsistent. Our goal was to evaluate the 6MWT in assessing the risk of cardiopulmonary complications in candidates for lung resection. We performed a retrospective assessment of clinical data and pulmonary function test results in 947 patients, mean age 65.3 (standard deviation 9.5) years, who underwent a single lobectomy for lung cancer. In 555 patients with predicted postoperative values ≤60%, the 6MWT was performed. The 6-min walking distance (6MWD) and the distance-saturation product (DSP), which is the product of the 6MWD in metres, and the lowest oxygen saturation registered during the test were assessed. A total of 363 patients with predicted postoperative values <60% and a 6MWT distance (6MWD) ≥400 m or DSP ≥ 350 m% had a lower rate of cardiopulmonary complications than patients with shorter 6MWD or lower DSP values [odds ratio (OR) 0.53, 95% confidence interval (CI) 0.35-0.81] and 0.47 (95% CI 0.30-0.73), respectively. This result was also true for patients with predicted postoperative values <40%, ORs 0.33 (95% CI 0.14-0.79) and 0.25 (95% CI 0.10-0.61), respectively. The 6MWT is useful in the assessment of operative risk in patients undergoing a single lobectomy for lung cancer. It helps to stratify the operative risk, which is lower in patients with 6MWD ≥400 m or DSP ≥350 m% than in patients with a shorter 6MWD or lower DSP values.

Parsimonious Eurolung risk models to predict cardiopulmonary morbidity and mortality following anatomic lung resections: an updated analysis from the European Society of Thoracic Surgeons database.

To develop a simplified version of the Eurolung risk model to predict cardiopulmonary morbidity and 30-day mortality after lung resection from the ESTS database. A total of 82383 lung resections (63681 lobectomies, 3617 bilobectomies, 7667 pneumonectomies and 7418 segmentectomies) recorded in the ESTS database (January 2007-December 2018) were analysed. Multiple imputations with chained equations were performed on the predictors included in the original Eurolung models. Stepwise selection was then applied for determining the best logistic model. To develop the parsimonious models, different models were tested eliminating variables one by one starting from the less significant. The models' prediction power was evaluated estimating area under curve (AUC) with the 10-fold cross-validation technique. Cardiopulmonary morbidity model (Eurolung1): the best parsimonious Eurolung1 model contains 5 variables. The logit of the parsimonious Eurolung1 model was as follows: -2.852 + 0.021 × age + 0.472 × male -0.015 × ppoFEV1 + 0.662×thoracotomy + 0.324 × extended resection. Pooled AUC is 0.710 [95% confidence interval (CI) 0.677-0.743]. Mortality model (Eurolung2): the best parsimonious model contains 6 variables. The logit of the parsimonious Eurolung2 model was as follows: -6.350 + 0.047 × age + 0.889 × male -0.055 × BMI -0.010 × ppoFEV1 + 0.892 × thoracotomy + 0.983 × pneumonectomy. Pooled AUC is 0.737 (95% CI 0.702-0.770). An aggregate parsimonious Eurolung2 was also generated by repeating the logistic regression after categorization of the numeric variables. Patients were grouped into 7 risk classes showing incremental risk of mortality (P < 0.0001). We were able to develop simplified and updated versions of the Eurolung risk models retaining the predictive ability of the full original models. They represent a more user-friendly tool designed to inform the multidisciplinary discussion and shared decision-making process of lung resection candidates.

Ventilatory Efficiency Identifies Patients Prone to Hypoxemia During One-Lung Ventilation

One-lung ventilation (OLV) may be complicated by hypoxemia. Ventilatory efficiency, defined as the ratio of minute ventilation to carbon dioxide output (VE/VCO2), is increased with ventilation/perfusion mismatch and pulmonary artery hypertension, both of which may be associated with hypoxemia. Hence, the authors hypothesized increased VE/VCO2 will predict hypoxemia during OLV. Prospective observational study. Single-center, university, tertiary care hospital. The study comprised 50 consecutive lung resection candidates. All patients underwent cardiopulmonary exercise testing before surgery. Patients who required inspired oxygen fraction (FiO2) ≥0.7 to maintain arterial oxygen (O2) saturation >90% after 30 minutes of OLV were considered to be hypoxemic. The Student t or Mann-Whitney U test were used for comparison of patients who became hypoxemic and those who did not. Multiple regression analysis adjusted for age, sex, and body mass index was used to evaluate which parameters were associated with the VE/VCO2 slope. Data are summarized as mean ± standard deviation. Twenty-four patients (48%) developed hypoxemia. There was no significant difference in age, sex, and body mass index between hypoxemic and nonhypoxemic patients. However, patients with hypoxemia had a significantly higher VE/VCO2 slope (30 ± 5 v 27 ± 4; p = 0.04) with exercise and lower partial pressure of oxygen/FiO2 (129 ± 92 v 168 ± 88; p = 0.01), higher mean positive end-expiratory pressure (6.6 ± 1.5 v 5.6 ± 0.9 cmH2O; p = 0.02), and lower mean pulse oximetry O2 saturation/FiO2 index (127 ± 20 v 174 ± 17; p < 0.01) during OLV. Multiple regression showed VE/VCO2 to be independently associated with the mean pulse oximetry O2 saturation/FiO2 index (b = -0.28; F = 3.1; p = 0.05). An increased VE/VCO2 slope may predict hypoxemia development in patients who undergo OLV.

Physician Gender Differences in Processing Surgical Risk Features in Videos of Standardized Patients

Physician gender differences exist for estimating surgical risk and recommending lung resection. This study assessed gender differences in perceived importance of health characteristics portrayed by standardized patients posing as lung resection candidates. Physicians read a clinical vignette categorized as low, average, or high surgical risk and then viewed a video of a standardized patient exhibiting vigorous, normal, or frail behavior. The relative importance of gait speed, strength, fatigue, age, and weight loss in the videos was scored on a five-point Likert-like scale. Ratings of the importance of each were compared by gender and risk category. Of 73 participating physicians, 62 were male and 11 were female, 40 were thoracic surgeons, and 33 were cardiothoracic surgical trainees. All video features were scored as very important or somewhat important a majority of the time. Gait speed and strength ratings were strongly correlated (r= 0.76), followed by strength and fatigue (r= 0.52) and gait speed and fatigue (r= 0.51). Female gender was associated with significantly greater odds of rating age as very important (p= 0.040). For weight loss, the differences between genders varied significantly (females consistently rated weight loss as important, whereas ratings for men varied by risk category; p= 0.002 for the interaction). Physicians variably rate certain health characteristics of standardized patients as important in making surgical risk estimations. Women and men rate the importance of age and weight loss differently. These findings may help educate physicians to develop more consistent estimates of surgical risk.

Surgical management of non-cystic fibrosis bronchiectasis.

Non-cystic fibrosis bronchiectasis (bronchiectasis) is an abnormal dilatation of the bronchi and bronchioles, resulting from a prolonged recurrent infectious process due to various causes and predisposing factors. This disease has several etiologies and affects a heterogeneous population of patients. The most important viewpoint for the surgical management of bronchiectasis is to select appropriate candidates for surgery and conduct suitable anatomic lung resections at the right time under appropriate conditions. The ideal candidates for lung resection are symptomatic patients with focal disease due to truly localized bronchial pathology regardless of optimal and absolute medical management.

Does Race Influence Risk Assessment and Recommendations for Lung Resection? A Randomized Trial

Racial disparities in use of surgical therapy for lung cancer exist in the United States. Videos of standardized patients (SPs) can help identify factors that influence physicians' surgical risk estimation. We hypothesized that physician race and SP race in videos influence surgeon decision making. Four race-neutral clinical vignettes representing lung resection candidates were paired with risk-level concordant short silent videos of SPs. Vignette/video combinations were classified as low or high risk. Trainees and practicing thoracic surgeons read a race-neutral vignette, provided an initial estimate of the percentage risk of major surgical complications, viewed a video randomized to a black or white SP, provided a final estimate of risk, and scored the likelihood that they would recommend operative therapy. Changes in risk estimates were assessed. Participants included 113 surgeons (38 practicing surgeons, 75 trainees); of these, 76 were white non-Hispanic (67%), and 37 were other self-identified racial categories. Percentage changes between initial and final risk estimates were not significantly related to patient race (p= 0.11) or surgeon race (white versus other; p= 0.52). Videos of black SPs were associated with a similar likelihood of recommending an operation compared with that of videos of white SPs (p= 0.90). Physician race (white versus other) was not related to the likelihood of recommending surgical intervention (p= 0.79). Neither patient nor physician race was significantly associated with risk estimation or surgical recommendations. These findings do not provide an explanation for documented racial disparities in lung cancer therapy. Further investigation is needed to identify the mechanism underlying these disparities.

The Influence of Physician and Patient Gender on Risk Assessment for Lung Cancer Resection

Women do not receive appropriate surgical therapy for lung cancer as often as men. Patient gender may influence treatment recommendations; less is known about the effect of physician gender on recommendations. Gender-neutral vignettes representing low-risk, average-risk, and high-risk candidates for lung resection were paired with concordant videos of standardized patients (SPs). Cardiothoracic trainees and practicing thoracic surgeons read a vignette, provided an initial estimate of the percentage risk of major adverse events after lung resection, viewed a video (randomized to male or female SP), provided a final estimate of risk, and ranked the importance of the video in the final risk estimate. Overall, 107 surgeons participated, of whom 90 were men. Initial estimated risks mirrored actual vignette risks: 10.4% ± 9.9 for low risk, 17.6% ± 13.2 for average risk, and 21.0% ± 14.7 for high risk (p < 0.001). After SP videos were viewed and final risk estimates were rendered, there was a significant difference between male and female physicians in the absolute change in estimated risk (p= 0.002), with male physicians having larger changes than female physicians. There was also an effect of SP gender that varied by vignette type (p < 0.001). Increasing video importance scores were directly associated with increasing change in risk scores for average-risk and high-risk vignette/video combinations (p < 0.001 for each). Differences in estimating complication risk for lung resection candidates are related to physician and patient gender. This may influence recommendations for surgical treatment. Understanding such differences may help reduce inequities in treatment recommendations.