Identifying patients at higher risk of pneumonia after lung resection

Risk factors and prognostic significance of early postoperative complications for patients who underwent pneumonectomy for lung cancer

BACKGROUND

Although pneumonectomy has relatively high mortality and morbidity rates, it remains valid in the surgical treatment of lung cancer. This study aims to evaluate the prognostic significance of postoperative complications after pneumonectomy and demonstrate the risk factors related to early postoperative complications.

METHODS

Patients who underwent pneumonectomy for non-small cell lung cancer between January 2008 and May 2021 were included in the study. Factors related to the development of early postoperative complications and overall survival were evaluated by univariate and multivariate analyses.

RESULTS

A total of 136 patients were included in the study. Early postoperative complications were seen in 33 (24.3%) patients and late postoperative complications in 7 (5.1%) patients. The amount of cigarette smoking, and the operation side were the independent variables that affect the development of early postoperative complications. In multivariate analysis, smoking amount and pericardial invasion were associated with the development of postoperative hemorrhage, and advanced age was associated with the development of postoperative pneumonia.

CONCLUSIONS

Early postoperative complications have a negative effect on the prognosis after pneumonectomy therefore careful patient selection and preoperative risk assessment are essential to minimize the occurrence of complications and improve patient outcomes.

TRIAL REGISTRATION

This observational study was approved by the (Ethical Committee of Dr. Suat Seren Chest Diseases and Chest Surgery Education and Research Center) Institutional Review Board of our center (E-49109414-604.02.02-218625439).

Diagnostic value of systematic bronchial aspirate on postoperative pneumonia after pulmonary resection surgery for lung cancer: a monocentre retrospective study

OBJECTIVES

Intraoperative bacterial airway colonization seems to be associated with an increased risk of postoperative pneumonia (POP). It can be easily assessed by performing a bronchial aspirate (BA). The objective of this study is to assess the diagnostic performance of the BA to predict POP.

METHODS

We conducted a single-centre retrospective observational study over a period of 10 years, from 1 January 2011 to 30 December 2020. The population study included patients admitted for a scheduled pulmonary resection surgery for lung cancer. Patients were classified into 2 populations depending on whether or not they developed a POP. Uni- and multivariable analyses were performed to identify risk factors for developing POP. The diagnostic performance of BA was represented by its sensitivity, specificity and positive and negative predictive values.

RESULTS

A total of 1006 patients were included in the study. Uni- and multivariable analyses found that a positive BA was independently associated with a greater risk of developing POP with an odds ratio of 6.57 [4.165-10.865]; P < 0.001. Its specificity was 95%, sensitivity was 31%, positive predictive value was 66% and negative predictive value was 81%.

CONCLUSIONS

A positive intraoperative BA is an independent risk factor for POP after lung cancer surgery. Further trials are required to validate the systematic implementation of BA as an early diagnostic tool for POP.

Nomogram prediction model of postoperative pneumonia in patients with lung cancer: A retrospective cohort study

Background

The prediction model of postoperative pneumonia (POP) after lung cancer surgery is still scarce.

Methods

Retrospective analysis of patients with lung cancer who underwent surgery at The Fourth Hospital of Hebei Medical University from September 2019 to March 2020 was performed. All patients were randomly divided into two groups, training cohort and validation cohort at the ratio of 7:3. The nomogram was formulated based on the results of multivariable logistic regression analysis and clinically important factors associated with POP. Concordance index (C-index), receiver operating characteristic (ROC) curve, calibration curve, Hosmer-Lemeshow goodness-of-fit test and decision curve analysis (DCA) were used to evaluate the predictive performance of the nomogram.

Results

A total of 1252 patients with lung cancer was enrolled, including 877 cases in the training cohort and 375 cases in the validation cohort. POP was found in 201 of 877 patients (22.9%) and 89 of 375 patients (23.7%) in the training and validation cohorts, respectively. The model consisted of six variables, including smoking, diabetes mellitus, history of preoperative chemotherapy, thoracotomy, ASA grade and surgery time. The C-index from AUC was 0.717 (95%CI:0.677-0.758) in the training cohort and 0.726 (95%CI:0.661-0.790) in the validation cohort. The calibration curves showed the model had good agreement. The result of DCA showed that the model had good clinical benefits.

Conclusion

This proposed nomogram could predict the risk of POP in patients with lung cancer surgery in advance, which can help clinician make reasonable preventive and treatment measures.

Evaluation of gastroesophageal reflux disease and hiatal hernia as risk factors for lobectomy complications

Objective

Up to 40% of lobectomies are complicated by adverse events. Gastroesophageal reflux disease (GERD) and hiatal hernia have been associated with morbidity across a range of clinical scenarios, yet their relation to recovery from pulmonary resection is understudied. We evaluated GERD and hiatal hernia as predictors of complications after lobectomy for lung cancer.

Methods

Lobectomy patients at Yale-New Haven Hospital between January 2014 and April 2021 were evaluated for predictors of 30-day postoperative complications, pneumonia, atrial arrhythmia, readmission, and mortality. Multivariable regression models included sociodemographic characteristics, body mass index, surgical approach, cardiopulmonary comorbidities, hiatal hernia, GERD, and preoperative acid-suppressive therapy as predictors.

Results

Overall, 824 patients underwent lobectomy, including 50.5% with a hiatal hernia and 38.7% with GERD. The median age was 68 [interquartile range, 61-74] years, and the majority were female (58.4%). At least 1 postoperative complication developed in 39.6% of patients, including atrial arrhythmia (11.7%) and pneumonia (4.1%). Male sex (odds ratio [OR], 1.51; 95% confidence interval [CI], 1.11-2.06, P = .01), age ≥70 years (OR, 1.55; 95% CI, 1.13-2.11, P = .01), hiatal hernia (OR, 1.40; 95% CI, 1.03-1.90, P = .03), and intraoperative packed red blood cells (OR, 4.80; 95% CI, 1.51-15.20, P = .01) were significant risk factors for developing at least 1 postoperative complication. Hiatal hernia was also a significant predictor of atrial arrhythmia (OR, 1.64; 95% CI, 1.02-2.62, P = .04) but was not associated with other adverse events.

Conclusions

Our findings indicate that hiatal hernia may be a novel risk factor for complications, especially atrial arrhythmia, following lobectomy that should be considered in the preoperative evaluation of lung cancer patients.

An External-Validated Algorithm to Predict Postoperative Pneumonia Among Elderly Patients With Lung Cancer After Video-Assisted Thoracoscopic Surgery

The aim of the study was to develop an algorithm to predict postoperative pneumonia among elderly patients with lung cancer after video-assisted thoracoscopic surgery. We analyzed 3,009 patients from the Thoracic Perioperative Database for Geriatrics in our hospital and finally enrolled 1,585 elderly patients (age≧65 years) with lung cancer treated with video-assisted thoracoscopic surgery. The included patients were randomly divided into a training group (n = 793) and a validation group (n = 792). Patients in the training group were used to develop the algorithm after screening up to 30 potential risk factors, and patients in the validation group were used to internally validate the algorithm. External validation of the algorithm was achieved in the external validation dataset after enrolling 165 elderly patients with lung cancer treated with video-assisted thoracoscopic surgery from two hospitals in China. Of all included patients, 9.15% (145/1,585) of patients suffered from postoperative pneumonia in the Thoracic Perioperative Database for Geriatrics, and 10.30% (17/165) of patients had postoperative pneumonia in the external validation dataset. The algorithm consisted of seven variables, including sex, smoking, history of chronic obstructive pulmonary disease (COPD), surgery duration, leukocyte count, intraoperative injection of colloid, and intraoperative injection of hormone. The C-index from the receiver operating characteristic curve (AUROC) was 0.70 in the training group, 0.67 in the internal validation group, and 0.71 in the external validation dataset, and the corresponding calibration slopes were 0.88 (95% confident interval [CI]: 0.37–1.39), 0.90 (95% CI: 0.46–1.34), and 1.03 (95% CI: 0.24–1.83), respectively. The actual probabilities of postoperative pneumonia were 5.14% (53/1031) in the low-risk group, 15.07% (71/471) in the medium-risk group, and 25.30% (21/83) in the high-risk group (p < 0.001). The algorithm can be a useful prognostic tool to predict the risk of developing postoperative pneumonia among elderly patients with lung cancer after video-assisted thoracoscopic surgery.

Use of Machine Learning to Develop and Evaluate Models Using Preoperative and Intraoperative Data to Identify Risks of Postoperative Complications

IMPORTANCE

Postoperative complications can significantly impact perioperative care management and planning.

OBJECTIVES

To assess machine learning (ML) models for predicting postoperative complications using independent and combined preoperative and intraoperative data and their clinically meaningful model-agnostic interpretations.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study assessed 111 888 operations performed on adults at a single academic medical center from June 1, 2012, to August 31, 2016, with a mean duration of follow-up based on the length of postoperative hospital stay less than 7 days. Data analysis was performed from February 1 to September 31, 2020.

MAIN OUTCOMES AND MEASURES

Outcomes included 5 postoperative complications: acute kidney injury (AKI), delirium, deep vein thrombosis (DVT), pulmonary embolism (PE), and pneumonia. Patient and clinical characteristics available preoperatively, intraoperatively, and a combination of both were used as inputs for 5 candidate ML models: logistic regression, support vector machine, random forest, gradient boosting tree (GBT), and deep neural network (DNN). Model performance was compared using the area under the receiver operating characteristic curve (AUROC). Model interpretations were generated using Shapley Additive Explanations by transforming model features into clinical variables and representing them as patient-specific visualizations.

RESULTS

A total of 111 888 patients (mean [SD] age, 54.4 [16.8] years; 56 915 [50.9%] female; 82 533 [73.8%] White) were included in this study. The best-performing model for each complication combined the preoperative and intraoperative data with the following AUROCs: pneumonia (GBT), 0.905 (95% CI, 0.903-0.907); AKI (GBT), 0.848 (95% CI, 0.846-0.851); DVT (GBT), 0.881 (95% CI, 0.878-0.884); PE (DNN), 0.831 (95% CI, 0.824-0.839); and delirium (GBT), 0.762 (95% CI, 0.759-0.765). Performance of models that used only preoperative data or only intraoperative data was marginally lower than that of models that used combined data. When adding variables with missing data as input, AUROCs increased from 0.588 to 0.905 for pneumonia, 0.579 to 0.848 for AKI, 0.574 to 0.881 for DVT, 0.5 to 0.831 for PE, and 0.6 to 0.762 for delirium. The Shapley Additive Explanations analysis generated model-agnostic interpretation that illustrated significant clinical contributors associated with risks of postoperative complications.

CONCLUSIONS AND RELEVANCE

The ML models for predicting postoperative complications with model-agnostic interpretation offer opportunities for integrating risk predictions for clinical decision support. Such real-time clinical decision support can mitigate patient risks and help in anticipatory management for perioperative contingency planning.

Long-Term Outcomes of a Preoperative Lung Resection Smoking Cessation Program

BACKGROUND

Smoking cessation programs for patients with cancer suggest 6-mo quit rates between 22% and 40%, and 1-y rates of 33%. We sought to investigate the long-term outcomes of an intensive, preoperative smoking cessation program in patients undergoing lung resection.

MATERIAL AND METHODS

A retrospective analysis of an IRB-approved, prospective database was performed. Elective lung resections between January 1, 2015 and June 30, 2017 were identified. Demographics, smoking status, pack years, occurrence of smoking cessation counseling, complications, and quit date were obtained. Smoking cessation included face-to-face motivational interviewing, choice of nicotine replacement therapy, discussion that surgery may be canceled or delayed without cessation, and follow-up as needed.

RESULTS

A total of 340 patients underwent lung resection. Of these, 82 patients were classified as current smokers. All were advised to quit and encouraged to meet with a certified tobacco treatment specialist. Sixty-three patients met with a tobacco treatment specialist and 19 did not. Overall, 60 patients (73%) were able to quit before surgery. At 2 y postoperatively, 15 (18%) were lost to follow-up and 9 (11%) had died. Excluding deaths and censoring those lost to follow-up, cessation rates at 6, 12, and 24 mo postoperatively were 55.3%, 55.6%, and 51.7%, respectively.

CONCLUSIONS

Implementation of an intensive smoking cessation program in the preoperative period demonstrated high initial, mid-term, and long-term success rates. The preoperative period, particularly one centered around lung cancer, is an effective time for smoking cessation intervention and can lead to a high rate of cessation up to 2 y after surgery.

Smoking is associated with pneumonia development in lung cancer patients

Background

Various host factors can promote pneumonia susceptibility of lung cancer patients. However, data about risk factors for pneumonia in lung cancer patients receiving active treatments such as chemotherapy, radiotherapy, and surgical intervention are limited. Thus, the purpose of this study was to identify risk factors for pneumonia development in lung cancer patients.

Methods

The present study used a lung cancer cohort of the Catholic Medical Center at the Catholic University of Korea from January 2015 to December 2018. Pneumonia was defined by the presence of a new or progressive infiltration on chest imaging together with any of the following: new onset purulent sputum, change in character of chronic sputum, and fever. We ruled out noninfectious infiltration such as drug or radiation toxicity and hydrostatic pulmonary edema. We especially excluded those if computed tomography revealed sharp demarcation consolidation or ground glass opacity limited radiation field.

Results

A total of 413 patients were enrolled in this study. Pneumonia occurred in 118 (28.6%) patients. The pneumonia group had significantly worse overall survival (OS) than the non-pneumonia group (456.7 ± 35.0 days vs. 813.4 ± 36.1 days, log rank p < 0.001). In patients with pneumonia, OS was shorter in ex-smokers and current smokers than in never smokers (592.0 ± 101.0 days vs. 737.0 ± 102.8 days vs. 1357.0 days, log rank p < 0.001). Age (hazard ratio [HR]: 1.046; 95% confidence interval [CI]: 1.019–1.074; p = 0.001), clinical stage IV (HR: 1.759; 95% CI: 1.004–3.083; p = 0.048), neutropenia (HR: 2.620; 95% CI: 1.562–4.396; p < 0.001], and smoking (HR: 2.040; 95% CI: 1.100–3.784; p = 0.024) were independent risk factors of pneumonia development in lung cancer patients in multivariate analysis. In subgroup analysis for patients treated with chemotherapy, age (HR: 1.043; 95% CI: 1.012–1.074; p = 0.006), neutropenia (HR: 3.199; 95% CI: 1.826–5.605; p < 0.001), and smoking (HR: 2.125; 95% CI: 1.071–4.216; p = 0.031) were independent risk factors of pneumonia development.

Conclusions

Smoking and neutropenia were risk factors affecting pneumonia development in the total group and subgroup of patients with lung cancer.

Unhealthy alcohol use is associated with postoperative complications in veterans undergoing lung resection

Background

Lung resections carry a significant risk of complications necessitating the characterization of peri-operative risk factors. Unhealthy alcohol use represents one potentially modifiable factor. In this retrospective cohort study, the largest to date of lung resections in the Veterans Health Administration (VHA), we examined the association between unhealthy alcohol use and postoperative complications and mortality.

Methods

Veterans Affairs Surgical Quality Improvement Program data recorded at 86 medical centers between 2007 and 2011 were used to identify 4,715 patients that underwent lung resection. Logistic regression models, adjusted for demographics and comorbidities, were fit to assess the association between unhealthy alcohol use (report of >2 drinks per day in the 2 weeks preceding surgery) and 30-day outcomes.

Results

Among 4,715 patients that underwent pulmonary resection, 630 (13.4%) reported unhealthy alcohol use (>2 drinks/day). Overall, postoperative complications occurred in 896 (19.0%) patients, including pneumonia in 524 (11.1%). The rate of mortality was 2.6%. In adjusted analyses, complications were significantly more common among patients with unhealthy alcohol use [odds ratio (OR), 1.42; 95% confidence interval (CI), 1.15-1.74] including, specifically, pneumonia (OR, 1.69; 95% CI, 1.32-2.15). No statistically significant association was identified between unhealthy alcohol use and mortality (OR, 1.27; 95% CI, 0.75-2.02). In secondary analyses that stratified by smoking status at the time of surgery, drinking more than 2 drinks per day was associated with post-operative complications in patients reporting current smoking (OR, 1.51; 95% CI, 1.18-1.91) and was not identified in those reporting no current smoking at the time of surgery (OR, 1.23; 95% CI, 0.79-1.85).

Conclusions

In this large VHA study, 13% of patients undergoing lung resection reported drinking more than 2 drinks per day in the preoperative period, which was associated with increased risk of post-operative complications. Unhealthy alcohol use may be an important target for perioperative risk-mitigation interventions, particularly in patients who report current smoking.