Surgical site infections after lung resection: a prospective study of risk factors in 1,091 consecutive patients

Postoperative lymphopaenia as a risk factor for postoperative infections in cancer surgery: A prospective multicentre cohort study (the EVALYMPH study)

BACKGROUND

Stress due to surgical trauma decreases postoperative lymphocyte counts (LCs), potentially favouring the occurrence of postoperative infections (PIs).

OBJECTIVES

We aimed to determine whether postoperative lymphopaenia following thoracic or gastrointestinal cancer surgery is an independent risk factor for PIs and to identify modifiable factors related to anaesthesia and surgical procedures that might affect its occurrence.

STUDY DESIGN

The EVALYMPH study was a prospective, multicentre cohort study with a 30-day patient follow-up. Multivariate analyses were performed to determine the risk factors for PIs and for postoperative lymphopaenia.

SETTING

Patients were included from January 2016 to September 2017 in 25 French centres.

PATIENTS

Adult patients admitted for thoracic or gastrointestinal cancer surgery were eligible for inclusion.

MAIN OUTCOME MEASURE

PIs within 30 days after surgery were defined as urinary tract infections, pneumonia, surgical site infections and other infections (bloodstream infections or pleurisy).

RESULTS

Of 1207 patients included, 273 (22.6%) developed at least one infection within 30 days after surgery, with a median [IQR] time to onset of 8 [5 to 11] days. An increased risk of PI was significantly associated with an ASA score of IV: hazard ratio (HR) 4.27 (95% confidence interval (CI), 1.87 to 9.72), surgery > 200 min (HR 1.58 (1.15 to 2.17) and lymphopaenia on postoperative day 1 (POD1) (HR 1.56 (1.08 to 2.25). This risk was associated with changes in postoperative LC over time ( P  = 0.001) but not with preoperative LC ( P  = 0.536).POD1 lymphopenia was related to patient characteristics and duration of surgery but not to potentially modifiable other surgical or anaesthetics factors.

CONCLUSIONS

POD1 lymphopaenia was associated with PIs in patients undergoing thoracic or gastrointestinal cancer surgery. To individualise care, patient characteristics and surgery duration should be taken into account.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02799251.

Meta-lasso: new insight on infection prediction after minimally invasive surgery

Surgical site infection (SSI) after minimally invasive lung cancer surgery constitutes an important factor influencing the direct and indirect economic implications, patient prognosis, and the 5-year survival rate for early-stage lung cancer patients. In the realm of predictive healthcare, machine learning algorithms have been instrumental in anticipating various surgical outcomes, including SSI. However, accurately predicting infection after minimally invasive surgery remains a clinical challenge due to the multitude of physiological and surgical factors associated with it. Furthermore, clinical patient data, in addition to being high-dimensional, often exists the long-tail problem, posing difficulties for traditional machine learning algorithms in effectively processing such data. Based on this insight, we propose a novel approach called meta-lasso for infection prediction following minimally invasive surgery. Our approach leverages the sparse learning algorithm lasso regression to select informative features and introduces a meta-learning framework to mitigate bias towards the dominant class. We conducted a retrospective cohort study on patients who had undergone minimally invasive surgery for lung cancer at Shanghai Chest Hospital between 2018 and 2020. The evaluation encompassed key performance metrics, including sensitivity, specificity, precision (PPV), negative predictive value (NPV), and accuracy. Our approach has surpassed the performance of logistic regression, random forest, Naive Bayes classifier, gradient boosting decision tree, ANN, and lasso regression, with sensitivity at 0.798, specificity at 0.779, precision at 0.789, NPV at 0.798, and accuracy at 0.788 and has greatly improved the classification performance of the inferior class.

[Diagnosis and treatment of bronchopleural fistula after anatomical lung resections]

OBJECTIVE

To assess the factors causing air leakage after anatomical lung resections and present a rational tactical approach for timely establishing the cause and level of bronchial fistula.

MATERIAL AND METHODS

We analyzed 723 patients who underwent anatomical lung resection (pneumonectomy - 136 patients, anatomical lobectomy and segmentectomy - 513, video-assisted anatomical resection - 74 patients).

RESULTS

In 506 (69.9%) cases, complete lung inflation after surgery was observed within 24-48 hours. Persistent air discharge for more than 3 days was observed in 141 (19.5%) patients. Prolonged air leakage for more than 7 postoperative days occurred in 50 (6.9%) patients. Air discharge for more than 10 days was considered abnormal and observed in 20 (2.8%) patients. Redo surgeries were performed in 49 patients with bronchopleural fistula at the level of segmental bronchi. Forty-two patients after primary thoracoscopy and 6 ones after primary thoracotomy underwent video-assisted resection of the lung with bronchopleural fistula after previous surgery. In 11 patients, re-thoracotomy was performed: middle lobectomy after previous right-sided upper lobectomy in 2 patients, lung resection after previous segmentectomy in 8 cases and atypical resection of bulla after previous right-sided lower lobectomy in 1 case.

CONCLUSION

Surgical approach for persistent postoperative air leakage involves various surgical interventions. The best option is minimally invasive thoracoscopic procedure. This method is valuable to visualize bronchopleural fistula, eliminate air leakage, additionally reinforce pulmonary suture and perform targeted adequate drainage of the pleural cavity.

The Spectrum of Infections in Patients with Lung Cancer

Although diagnostic and therapeutic advances in lung cancer (LC) have increased the survival of patients, infection and its complications are still among the most important causes of mortality. The disruption of tissue caused by tumor mass, management of cancer therapy and alteration in the humoral/cellular immune systems due to both cancer itself and therapy considerably increase susceptibility to infection in cancer patients. Particularly, opportunistic microorganisms should be considered, then applying rapid and sensitive diagnostic methods for them. Thus, cancer patients who are already exposed to difficult, long-term and expensive treatments can be prevented from dying from complications related to infections.

Development of a Nomogram for Predicting Surgical Site Infection in Patients with Resected Lung Neoplasm Undergoing Minimally Invasive Surgery

Background: Predictive models are necessary to target high-risk populations and provide precision interventions for patients with lung neoplasm who suffer from surgical site infections (SSI). Patients and Methods: This case control study included patients with lung neoplasm who underwent minimally invasive surgeries (MIS). Logistic regression was used to generate the prediction model of SSI, and a nomogram was created. A receiver operator characteristic (ROC) curve was used to examine the predictive value of the model. Results: A total of 151 patients with SSI were included, and 604 patients were randomly selected among the patients without SSI (ratio 4:1). Male gender (odds ratio [OR], 2.55; 95% confidence interval [CI], 1.57-4.15; p < 0.001), age >60 years (OR, 2.10; 95% CI, 1.29-3.44, p = 0.003), operation time >60 minutes (all categories, p < 0.05), treatments for diabetes mellitus (OR, 2.96; 95% CI, 1.75-4.98l; p < 0.001), and best forced expiratory volume in 1 second (FEV₁)/forced vital capacity (FVC; OR, 0.96; 95% CI, 0.94-0.99; p = 0.008) were independently associated with SSI. The model based on these variables showed an area under the curve (AUC) of 0.813 for predicting SSI. Conclusions: A nomogram predictive model was successfully established for predicting SSI in patients receiving MIS, with good predictive value.

Surgical Site Infection in Thoracic Surgery Is Not Associated With Perioperative Hypothermia

INTRODUCTION

The Surgical Care Improvement Project (SCIP) added the SCIP-Inf-10 measure to mandate that all surgical patients have perioperative temperature management to reduce surgical site infection. While the basis of this measure originated in colorectal surgery, we hypothesized that this would also apply to thoracic surgery patients.

METHODS

This was a retrospective single-center pilot study reviewing two years of thoracic surgery cases for the incidence and duration of hypothermia during the operation and surgical site infection occurring within 30 days. Hypothermia was defined as a core temperature of < 36° C.  Results: A total of 317 patients were included in the study. Sixty-two percent of patients were identified as hypothermic. The average intraoperative temperature was 35.4°C ± 0.8°C in the hypothermic group and 36.4°C ± 0.3°C in the normothermic group. There were four surgical site infections in the study with three cases from the <36°C group (p = 1). There was no difference in average post-anesthesia care unit length of stay between the groups. The average hospital length of stay was 5.5 ± 5.2 days for the hypothermic group and 8.6 ± 12.8 days for the normothermic group (p=0.0024).

CONCLUSION

Perioperative hypothermia was common in thoracic surgery and did not have a negative impact on surgical site infection.

Diagnostic value of routine chest tube tip culture in surgery for noninfectious lung disease

BACKGROUND

Evaluation of the diagnostic value of routine chest tube tip culture for detection of postoperative infection after surgery for noninfectious lung disease.

METHODS

Included subjects were patients who underwent lung surgery between January 1st 2013 and January 1st 2018 in University Medical Centre Utrecht and of whom a chest tube tip was cultured. Postoperative outcomes included pneumonia, surgical site infection, and empyema within 30 days after surgery. Univariable analysis for diagnostic accuracy of chest tube tip culture results predicting these postoperative outcomes was performed, as well as multivariable analysis using penalized firth logistic regression.

RESULTS

Patients developed one or more postoperative infections in 42 out of 210 (20%) lung surgeries. Pneumonia, surgical site infection, and empyema were found in 36 (17%), 8 (4%), and 2 (1%) cases respectively. Chest tube tip culture had a sensitivity of 31%, a specificity of 83%, a positive predictive value of 32%, and a negative predictive value of 83% for postoperative infections. In the subgroup of patients who did not have evidence of postoperative infection at the time of chest tube removal, the drain tip culture's positive and negative predictive value changed to 18% and 92% respectively. Adding additional variables to chest tube tip culture in a prediction model resulting in only limited improvement in diagnostic performance.

CONCLUSIONS

We found insufficient diagnostic performance to support the practice of routine chest tube tip culture after surgery for noninfectious lung disease. Therefore, routine chest tube tip culture is not advisable and should be omitted to unburden the healthcare process and prevent low value care together with extra costs.

Surgical Site Infections Are Associated With Higher Blood Loss and Open Access in General Thoracic Practice

Background: Surgical site infections (SSIs) are the most costly and second most frequent healthcare-associated infections in the Western world. They are responsible for higher postoperative mortality and morbidity rates and longer hospital stays. The aim of this study is to analyze which factors are associated with SSI in a modern general thoracic practice.

Methods: Data were collected from our department's quality database. Consecutive patients operated between January 2014 and December 2018 were included in this retrospective study.

Results: A total of 2430 procedures were included. SSIs were reported in 37 cases (1.5%). The majority of operations were video-assisted (64.6%). We observed a shift toward video-assisted thoracic surgery in the subgroup of anatomical resections during the study period (2014: 26.7%, 2018: 69.3%). The multivariate regression analysis showed that blood loss >100 ml (p = 0.029, HR 2.70) and open surgery (p = 0.032, HR 2.37) are independent risk factors for SSI. The latter was higher in open surgery than in video-assisted thoracic procedures (p < 0.001). In the subgroup of anatomical resection, we found the same correlation (p = 0.043). SSIs are also associated with significantly longer mean hospital stays (17.7 vs. 7.8 days, p < 0.001).

Conclusion: As SSIs represent higher postoperative morbidity and costs, efforts should be made to maintain their rate as low as possible. In terms of prevention of SSIs, video-assisted thoracic surgery should be favored over open surgery whenever possible.

A retrospective analysis of factors affecting surgical site infection in orthopaedic patients

Objective

To investigate the factors affecting surgical site infections (SSI) in patients undergoing orthopaedic surgery.

Methods

The electronic medical records of patients undergoing orthopaedic surgery between September 2010 and July 2018 were retrospectively retrieved and reviewed. Logistic regression analyses were used to analyse the correlation between surgery-related variables and SSI. The odds ratio (OR) and 95% confidence interval (CI) were estimated for the risk factors.

Results

Clinical data from 25 954 patients were reviewed and 804 (3.1%) were found to have become infected at the surgical site. Older age (≥60 years) was a risk factor (OR 2.218) and younger age (<18 years) was a protective factor (OR 0.258). Diabetes mellitus (OR 6.560) and hypertension (OR 3.991) were independent risk factors. Compared with type II incisions, type I incisions had a lower risk for SSI (OR 0.031), while type III incisions had a greater risk of SSI (OR 2.599). Compared with upper limbs and hands, the feet had a lower risk of infection, while surgery performed at the spine and joints did not increase the risk as compared with foot surgery.

Conclusion

Older age, hypertension, diabetes mellitus and type III incisions were risk factors for SSI following orthopaedic surgery.

Efficacy of preoperative white blood cell count and lymphocyte/monocyte ratio in predicting post-lobectomy pneumonia

Background

This study aims to examine preoperative white blood cell count and lymphocyte/monocyte ratio and to investigate foreknown risk factors for pneumonia following lobectomy.

Methods

Between January 2005 and May 2018, a total of 152 patients (135 males, 17 females; mean age: 61.9±7.5 years; range, 45 to 73 years) who underwent right lower lobectomy for non-small cell lung cancer were retrospectively analyzed. Data including age, sex, preoperative white blood cell count and lymphocyte/monocyte ratio, smoking, preexisting chronic diseases, body mass index, stage of lung cancer, the use of neoadjuvant chemotherapy, type of surgery, operation duration, blood transfusion, and postoperative intensive care unit admission were recorded.

Results

Twenty-five (16.4%) patients developed postoperative pneumonia. Older patients presenting with elevated levels of preoperative white blood cell count and lymphocyte/monocyte ratio, excessive tobacco consumption, prolonged operation duration, history of a chronic disease, a body mass index over 30 kg/m2, advanced lung cancer, neoadjuvant chemotherapy, and intensive care unit admission after surgery were at high risk for postoperative pneumonia. There was no significant difference in sex, type of surgery (thoracotomy versus thoracoscopy), and the use of blood products. In predicting the development of postoperative pneumonia, lymphocyte/monocyte ratio had 85.% sensitivity and 87.5% specificity, while white blood cell count had 72.5% sensitivity and 77.5% specificity.

Conclusion

Preoperative white blood cell count and lymphocyte/ monocyte ratio provide supporting evidence in predicting pneumonia following lobectomy contributing to the existing risk identification criteria.

A Retrospective Cohort Study of Risk Factors for Surgical Site Infection Following Lung Transplant

BACKGROUND

Surgical site infections (SSIs) are among the leading health care-associated infections as well as a major problem in the postoperative period of lung transplant recipients. Little is known about the risk factors in this specific population. The objective of this study was to identify the incidence, risk factors, and outcomes of SSI following lung transplant.

METHODS

Digital medical records of adult recipients subjected to lung transplant from July 2011 and June 2016 in a large Brazilian referral teaching public center were analyzed in this retrospective cohort follow-up.

RESULTS

Among the 121 recipients analyzed, 19 (15.7%) had SSI; of these, 11 (57.8%) had superficial incisional infections, 1 (5.2%) had a deep incisional infection, and 7 (36.8%) had organ/space infection. Recipient-related risk factors for SSI were high body mass index (P = .041), prolonged surgery time (P = .043), and prolonged duration of chest drain placement (P = .009). At the multiple logistic regression was found that each hour elapsed in the surgical time increased the odds of SSI by around 2 times (odds ratio 2.34; 95% CI, 1.46-4.53; P = .002). Donor-related risk factors included smoking status (P = .05) and positive bronchoalveolar lavage (P < .001). Having an SSI was associated with an increased length of stay in intensive care units (P = .003), reoperation (P = .014), and a higher 1-year mortality rate (P = .02).

CONCLUSIONS

The identified incidence rate was higher to that observed in the previous studies. The risk factors duration of chest tube placement and donor smoking status are different from those reported in the scientific literature.

Soft-Tissue Reconstruction after Composite Vertebrectomy and Chest Wall Resection for Spinal Tumors

BACKGROUND

Oncologic resections involving both the spine and chest wall commonly require immediate soft-tissue reconstruction. The authors hypothesized that reconstructions of composite resections involving both the thoracic spine and chest wall would have a higher complication rate than reconstructions for resections limited to the thoracic spine alone.

METHODS

The authors performed a retrospective analysis of all consecutive patients who underwent a thoracic vertebrectomy and soft-tissue reconstruction from 2002 to 2017. Patients were divided into two groups: those whose defect was limited to the thoracic spine and those who required a composite resection involving the chest wall.

RESULTS

One hundred patients were included. Composite resection patients had larger defects, as indicated by a greater incidence of multilevel vertebrectomies (70.2 percent versus 17 percent; p = 0.001). Thoracic spine patients were older (58.2 ± 10.4 years versus 48.6 ± 13.9 years; p < 0.001) and had a greater incidence of metastatic disease (88.7 percent versus 38.3 percent; p = 0.001). Univariate and multivariate logistic regression analyses demonstrated that composite resections were not significantly associated with a higher rate of surgical, medical, or overall complications. Multivariate logistic regression analysis of composite resection subgroup demonstrated that flap separation of the spinal cord from the intrapleural space was protective against complications (OR, 0.22; 95 percent CI, 0.05 to 0.81; p = 0.03).

CONCLUSIONS

Despite the large defect size in composite resection patients, there was no increase in complications compared to thoracic spine patients. In composite resection patients, separating the exposed spinal cord from the intrapleural space with well-vascularized soft tissue was protective against complications.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, II.