Mortality due to hospital-acquired infection after cardiac surgery

Association of adherence to individual components of Society of Thoracic Surgeons cardiac surgery antibiotic guidelines and postoperative infections

OBJECTIVES

The study objectives were to measure the association among the 4 components of Society of Thoracic Surgeons antibiotic guidelines and postoperative complications in a cohort of patients undergoing valve or coronary artery bypass grafting requiring cardiopulmonary bypass.

METHODS

In this retrospective observational study, adult patients undergoing coronary revascularization or valvular surgery who received a Surgical Care Improvement Project-compliant antibiotic from January 1, 2016, to April 1, 2021, at a single, tertiary care hospital were included. The primary exposures were adherence to the 4 individual components of Society of Thoracic Surgeons antibiotic best practice guidelines. The association of each component and a combined metric was tested in its association with the primary outcome of postoperative infection as determined by Society of Thoracic Surgeons data abstractors, controlling for several known confounders.

RESULTS

Of the 2829 included patients, 1084 (38.3%) received care that was nonadherent to at least 1 aspect of Society of Thoracic Surgeons antibiotic guidelines. The incidence of nonadherence to the 4 individual components was 223 (7.9%) for timing of first dose, 639 (22.6%) for antibiotic choice, 164 (5.8%) for weight-based dose adjustment, and 192 (6.8%) for intraoperative redosing. In adjusted analyses, failure to adhere to first dose timing guidelines was directly associated with Society of Thoracic Surgeons-adjudicated postoperative infection (odds ratio, 1.9; 95% confidence interval, 1.1-3.3; P = .02). Failure of weight-adjusted dosing was associated with both postoperative sepsis (odds ratio, 6.9; 95% confidence interval, 2.5-8.5; P < .01) and 30-day mortality (odds ratio, 4.3; 95% confidence interval, 1.7-11.4; P < .01). No other significant associations among the 4 Society of Thoracic Surgeons metrics individually or as a combination were observed with postoperative infection, sepsis, or 30-day mortality.

CONCLUSIONS

Nonadherence to Society of Thoracic Surgeons antibiotic best practices is common. Failure of antibiotic timing and weight-adjusted dosing is associated with odds of postoperative infection, sepsis, and mortality after cardiac surgery.

A nomogram predicting pneumonia after cardiac surgery: a retrospective modeling study

BACKGROUND

Postoperative pneumonia (POP) is the most prevalent of all nosocomial infections in patients who underwent cardiac surgery. The aim of this study was to identify independent risk factors for pneumonia after cardiac surgery, from which we constructed a nomogram for prediction.

METHODS

The clinical data of patients admitted to the Department of Cardiothoracic Surgery of Nanjing Drum Tower Hospital from October 2020 to September 2021 who underwent cardiac surgery were retrospectively analyzed, and the patients were divided into two groups according to whether they had POP: POP group (n=105) and non-POP group (n=1083). Preoperative, intraoperative, and postoperative indicators were collected and analyzed. Logistic regression was used to identify independent risk factors for POP in patients who underwent cardiac surgery. We constructed a nomogram based on these independent risk factors. Model discrimination was assessed via area under the receiver operating characteristic curve (AUC), and calibration was assessed via calibration plot.

RESULTS

A total of 105 events occurred in the 1188 cases. Age (>55 years) (OR: 1.83, P=0.0225), preoperative malnutrition (OR: 3.71, P<0.0001), diabetes mellitus(OR: 2.33, P=0.0036), CPB time (Cardiopulmonary Bypass Time) > 135 min (OR: 2.80, P<0.0001), moderate to severe ARDS (Acute Respiratory Distress Syndrome )(OR: 1.79, P=0.0148), use of ECMO or IABP or CRRT (ECMO: Extra Corporeal Membrane Oxygenation; IABP: Intra-Aortic Balloon Pump; CRRT: Continuous Renal Replacement Therapy )(OR: 2.60, P=0.0057) and MV( Mechanical Ventilation )> 20 hours (OR: 3.11, P<0.0001) were independent risk factors for POP. Based on those independent risk factors, we constructed a simple nomogram with an AUC of 0.82. Calibration plots showed good agreement between predicted probabilities and actual probabilities.

CONCLUSION

We constructed a facile nomogram for predicting pneumonia after cardiac surgery with good discrimination and calibration. The model has excellent clinical applicability and can be used to identify and adjust modifiable risk factors to reduce the incidence of POP as well as patient mortality.

Post-operative infections after cardiothoracic surgery and vascular procedures: a bibliometric and visual analysis of the 100 most-cited articles in the past 2 decades

Aim

To recognize and analyze the 100 most-cited articles on post-operative infections following cardiothoracic surgery and vascular procedures in the past 20 years.

Methods

Articles published on post-operative infections following cardiothoracic surgery and vascular procedures from inception 1986 till 2020 were reviewed and selected by two authors, based on their number of citations using the Scopus database. Their characteristics were recorded, i.e., title, authors, publication date, total no. of citations, citations per year (CPY), country of research, institutional affiliation, journal, research subject, and article type.

Results

The top 100 most influential articles were published between 1968 and 2017, with the peak in 2002. The mean number of total citations was 236.79 (range: 108-1,157). Areas with a medical focus were predominant in the studied research articles on the researched topic. The top-most journals in which these articles were published include Annals of Thoracic Surgery (14), followed by Circulation (8), and the New England Journal of Medicine (8). The number of publications affiliated with an institution were highest in the United States, with the Cleveland Clinic Foundation (6) having the most.

Conclusion

These findings highlight that there is a great potential to conduct research and publish the prevalence, causes, risk factors, pathogenesis and molecular biology of post-cardiac and -vascular surgery infections to prevent their adverse effects. The results can be taken into consideration for policy making to improve post-cardiac-surgery outcomes.

Risk factors for surgical site infection following cardiac surgery in a region endemic for multidrug resistant organisms

OBJECTIVES

To identify risk factors for surgical site infections following cardiosurgery in an area endemic for multidrug resistant organisms.

DESIGN

Single-center, historical cohort study including patients who underwent cardiosurgery during a 6-year period (2014-2020).

SETTING

Joint Commission International accredited, multiorgan transplant center in Palermo, Italy.

MAIN OUTCOME MEASURES

Surgical site infection was the main outcome.

RESULTS

On a total of 3609 cardiosurgery patients, 184 developed surgical site infection (5.1 %). Intestinal colonization with multidrug resistant organisms was more frequent in patients with surgical site infections (69.6 % vs. 33.3 %; p < 0.001). About half of surgical site infections were caused by Gram-negative bacteria (n = 97; 52.7 %). Fifty surgical site infections were caused by multidrug resistant organisms (27.1 %), with extended-spectrum Beta-lactamase-producing Enterobacterales (n = 16; 8.7 %) and carbapenem-resistant Enterobacterales (n = 26; 14.1 %) being the predominant resistance problem. However, in only 24 of surgical site infections caused by multidrug resistant organisms (48 %), mostly carbapenem-resistant Enterobacterales (n = 22), a pathogen match between the rectal surveillance culture and surgical site infections clinical culture was demonstrated. Nevertheless, multivariate logistic regression analysis identified a rectal swab culture positive for multidrug resistant organisms as an independent risk factor for SSI (odds ratio 3.95, 95 % confidence interval 2.79-5.60). Other independent risk factors were female sex, chronic dialysis, diabetes mellitus, previous cardiosurgery, previous myocardial infarction, being overweight/obese, and longer intubation time.

CONCLUSION

In an area endemic for carbapenem-resistant Enterobacterales, intestinal colonization with multidrug resistant organisms was recognized as independent risk factor for surgical site infections.

IMPLICATIONS FOR CLINICAL PRACTICE

No causal relationship between colonization with resistant pathogens and subsequent infection could be demonstrated. However, from a broader epidemiological perspective, having a positive multidrug resistant organisms colonization status appeared a risk factor for surgical site infections. Therefore, strict infection control measures to prevent cross-transmission remain pivotal (e.g., nasal decolonization, hand hygiene, and skin antisepsis).

Perioperative Management of Heart Transplantation: A Clinical Review

In this clinical review, the authors summarize the perioperative management of heart transplant patients with a focus on hemodynamics, immunosuppressive strategies, hemostasis and hemorrage, and the prevention and treatment of infectious complications.

Diagnosis of Early Bacterial Pneumonia and Sepsis After Cardiovascular Surgery: A Diagnostic Prediction Model Based on LASSO Logistic Regression

Background

Early postoperative bacterial pneumonia and sepsis (ePOPS), which occurs within the first 48 hours after cardiovascular surgery, is a serious life-threatening complication. Diagnosis of ePOPS is extremely challenging, and the existing diagnostic tools are insufficient. The purpose of this study was to construct a novel diagnostic prediction model for ePOPS.

Methods

Least Absolute Shrinkage and Selection Operator (LASSO) with logistic regression was used to construct a model to diagnose ePOPS based on patients' comorbidities, medical history, and laboratory findings. The area under the receiver operating characteristic curve (AUC) was used to evaluate the model discrimination.

Results

A total of 1203 patients were recruited and randomly split into a training and validation set in a 7:3 ratio. By early morning on the 3rd postoperative day (POD3), 103 patients had experienced 133 episodes of bacterial pneumonia or sepsis (15 patients had both). LASSO logistic regression model showed that duration of mechanical ventilation (P=0.015), NYHA class ≥ III (P=0.001), diabetes (P<0.001), exudation on chest radiograph (P=0.011) and IL-6 on POD3 (P<0.001) were independent risk factors. Based on these factors, we created a nomogram named DICS-I with an AUC of 0.787 in the training set and 0.739 in the validation set.

Conclusion

The DICS-I model may be used to predict the risk of ePOPS after cardiovascular surgery, and is also especially suitable for predicting the risk of IRAO. The DICS-I model could help clinicians to adjust antibiotics on the POD3.

Global incidence of surgical site infections following caesarean section: a systematic review and meta-analysis

BACKGROUND

Surgical site infection (SSI) is a health-threatening complication following caesarean section (CS); however, to the authors' knowledge, there is no worldwide estimate of the burden of post-CS SSIs. Therefore, this systematic review and meta-analysis aimed to estimate the global and regional incidence of post-CS SSIs and associated factors.

METHODS

International scientific databases were searched systematically for observational studies published from January 2000 to March 2023, without language or geographical restrictions. The pooled global incidence rate was estimated using a random-effects meta-analysis (REM), and then stratified by World-Health-Organization-defined regions as well as by sociodemographic and study characteristics. Causative pathogens and associated risk factors of SSIs were also analysed using REM. Heterogeneity was assessed with I2.

RESULTS

In total, 180 eligible studies (207 datasets) involving 2,188,242 participants from 58 countries were included in this review. The pooled global incidence of post-CS SSIs was 5.63% [95% confidence interval (CI) 5.18-6.11%]. The highest and lowest incidence rates for post-CS SSIs were estimated for the African (11.91%, 95% CI 9.67-14.34%) and North American (3.87%, 95% CI 3.02-4.83%) regions, respectively. The incidence was significantly higher in countries with lower income and human development index levels. The pooled incidence estimates have increased steadily over time, with the highest incidence rate during the coronavirus disease 2019 pandemic (2019-2023). Staphylococcus aureus and Escherichia coli were the most prevalent pathogens. Several risk factors were identified.

CONCLUSION

An increasing and substantial burden from post-CS SSIs was identified, especially in low-income countries. Further research, greater awareness and the development of effective prevention and management strategies are warranted to reduce post-CS SSIs.

Association between Hospital-Acquired Pneumonia and In-Hospital Mortality in Solid Organ Transplant Admissions: An Observational Analysis in Spain, 2004-2021

(1) Background: To analyze the association between hospital-acquired pneumonia (HAP) and in-hospital mortality (IHM) during hospital admission for solid organ transplant in Spain during 2004-2021. (2) Methods: We used national hospital discharge data to select all hospital admissions for kidney, liver, heart, and lung transplants. We stratified the data according to HAP status. To examine time trends, we grouped data into three consecutive 6-year periods (2004-2009; 2010-2015; and 2016-2021). We assessed in-hospital mortality (IHM) in logistic regression analyses and obtained odds ratios (ORs) with their 95% confidence intervals (CIs). (3) Results: We identified a total of 71,827 transplants (45,262, kidney; 18,127, liver; 4734, heart; and 4598, lung). Two thirds of the patients were men. Overall, the rate of HAP during admission was 2.6% and decreased from 3.0% during 2004-2009 to 2.4% during 2016-2021. The highest rate of HAP corresponded to lung transplant (9.4%), whereas we found the lowest rate for kidney transplant (1.1%). Rates of HAP for liver and heart transplants were 3.8% and 6.3%, respectively. IHM was significantly lower during 2016-2021 compared to 2004-2009 for all types of transplants (ORs (CIs) = 0.65 (0.53-0.79) for kidney; 0.73 (0.63-0.84) for liver; 0.72 (0.59-0.87) for heart; and 0.39 (0.31-0.47) for lung). HAP was associated with IHM for all types of transplants (ORs (CIs) = 4.47 (2.85-9.08) for kidney; 2.96 (2.34-3.75) for liver; 1.86 (1.34-2.57) for heart; and 2.97 (2.24-3.94) for lung). (4) Conclusions: Rates of HAP during admission for solid organ transplant differ depending on the type of transplant. Although IHM during admission for solid organ transplant has decreased over time in our country, HAP persists and is associated with a higher IHM after accounting for potential confounding variables.

Influence and risk factors of postoperative infection after surgery for ischemic cardiomyopathy

Background

Studies on postoperative infection (POI) after surgery for ischemic cardiomyopathy are still lacking. This study aimed to investigate the risk factors of POI and its influence on clinical outcomes in patients undergoing ischemic cardiomyopathy surgery.

Methods

The Surgical Treatment for Ischemic Heart Failure (STICH) trial randomized patients with ischemic cardiomyopathy [coronary artery disease (CAD) with left ventricular ejection fraction ≤35%] to surgical and medical therapy. In this study, a post hoc analysis of the STICH trial was performed to assess the risk factors and clinical outcomes of POI in those undergoing coronary artery bypass graft (CABG). Patients were divided according to whether POI developed during hospitalization or within 30 days from operation.

Results

Of the 2,136 patients randomized, 1,460 patients undergoing CABG per-protocol was included, with a POI rate of 10.2% (149/1,460). By multivariable analysis, POI was significantly related to patients' age, body mass index, depression, chronic renal insufficiency, Duke CAD Index, and mitral valve procedure. Compared to patients without POI, patients with POI had significantly longer durations of intubation, CCU/ICU and hospital stay, and higher rates of re-operation, in-hospital death and failed discharge within 30 days postoperatively. In addition, these patients had significantly higher risks of all-cause death, cardiovascular death, heart failure death, and all-cause hospitalization during long-term follow-up. However, the influence of POI on all-cause death was mainly found during the first year after operation, and the influence was not significant for patients surviving for more than 1 year.

Conclusions

POI was prevalent after surgery for ischemic cardiomyopathy and was closely related to short-term and long-term clinical outcomes, and the effect of POI mainly occurred within the first postoperative year. This study first reported and clarified the relationship between POI and long-term prognosis and the predictors for POI after surgery for ischemic cardiomyopathy worldwide, which may have certain guiding significance for clinical practice.

Clinical Trial Registration

https://www.clinicaltrials.gov, identifier (NCT00023595).

Impact of Post-Operative Infection after CABG on Long-Term Survival

Coronary artery bypass grafting (CABG) is one of the most common cardiac surgical procedures. It is commonly known that post-operative infection has a negative impact on the patient's short-term treatment outcomes and long-term prognosis. The aim of the present study was to assess the impact of perioperative infection on 5-year and 10-year survival in patients undergoing elective on-pump CABG surgery. The present prospective observational study was carried out between 1 July 2010 and 31 August 2012 among patients undergoing cardiac surgery at our centre. Infections were identified according to the ECDC definitions. We initially assessed the incidence of infection and its relationship with the parameters analysed. We then analysed the effect of particular parameters, including infection, on 5-year and 10-year survival after surgery. We also analysed the impact of particular types of infection on the risk of death within the period analysed. The significant risk factors for reduced survival were age (HR 1.05, CI 1.02-1.07), peripheral artery disease (HR 1.99, CI 1.28-3.10), reduced LVEF after surgery (HR 0.96, CI 0.94-0.99), post-operative myocardial infarction (HR 1.45, CI 1.05-2.02) and infection (HR 3.10, CI 2.20-4.28). We found a strong relationship between post-operative infections and 5-year and 10-year mortality in patients undergoing CABG. Pneumonia and BSI were the only types of infection that were found to have a significant impact on increased long-term mortality after CABG surgery.

Infections in Glucose-6-Phosphate Dehydrogenase G6PD-Deficient Patients; Predictors for Infection-Related Mortalities and Treatment Outcomes

Disturbances in the count or maturity of blood cells weaken their microbial defensive capacity and render them more susceptible to infections. Glucose-6-phosphate deficient patients are affected by a genetic disease that affects cell integrity with increased liability to infections and death. We aimed to investigate the risk factors for infection mortality in this patient population. We retrospectively examined the records of G6PD adult patients with confirmed infections and collected data related to demographics, infections (pathogens, types, and treatment regimens) in addition to mortality and length of stay outcomes. Data were statistically analyzed using R Programming language to identify contributing factors to mortality and treatment regimens association with outcomes. Records of 202 unique patients over 5 years were included, corresponding to 379 microbiologically and clinically confirmed infections. Patients > 60 years [p = 0.001, OR: 5.6], number of comorbidities 4 (2–5) [p < 0.001, OR: 1.8], patients needed blood transfusion [p = 0.003, OR: 4.3]. Respiratory tract infections [p = 0.037, OR: 2.28], HAIs [p = 0.002, OR: 3.9], polymicrobial infections [p = 0.001, OR: 10.9], and concurrent infection Gram-negative [p < 0.001, OR: 7.1] were significant contributors to 28-day mortality. The history of exposure to many antimicrobial classes contributed significantly to deaths, including β-lactam/β-lactamase [p = 0.002, OR: 2.5], macrolides [p = 0.001, OR: 3.34], and β-lactams [p = 0.012, OR: 2.0]. G6PD patients are a unique population that is more vulnerable to infections. Prompt and appropriate antimicrobial therapy is warranted to combat infections. A strict application of stewardship principles (disinfection, shortening the length of stay, and controlling comorbid conditions) may be beneficial for this population. Finally, awareness of the special needs of this patient group may improve treatment outcomes.

Impact of a Surgical Wound Infection Prevention Bundle in Pediatric Cardiothoracic Surgery

BACKGROUND

The aim of this project was to decrease the incidence of surgical wound infection (SWI) to <1.5% in our pediatric cardiothoracic surgery patients using a prevention bundle and quality improvement process.

METHODS

An SWI prevention bundle addressing preoperative, intraoperative, and postoperative risks was implemented. The primary outcome was SWI based on Society of Thoracic Surgeons criteria (superficial, deep, or mediastinitis). Novel aspects of the bundle included standardization of surgical closure and wound coverage for 14 days with a negative pressure dressing or a silicone dressing. Data were collected from January 2017 to November 2021; bundle intervention began in December 2019. SWIs were tracked using a g-chart. Preintervention and postintervention cohorts were compared by standard descriptive statistics. There were no changes in SWI tracking methods during the study.

RESULTS

During the study, 1159 individuals underwent 1768 surgical interventions. Preintervention (n = 931) and postintervention (n = 837) groups were clinically similar, with fewer neonatal surgeries in the postintervention group. SWI decreased in all patients (preintervention period: 1 SWI per 22 surgeries; postintervention period: 1 SWI per 62.6 surgeries) and in neonates (preintervention period: 1 SWI per 12 surgeries; postintervention period: 1 SWI per 26.7 surgeries). Special cause variation was achieved in the entire cohort by March 2021 and in neonates by April 2021. Decreases in SWI occurred in superficial and deep wounds but not in mediastinitis. Annual rate of total SWIs decreased from 2.83% in 2019 to 1.15% in 2021. Intensive care unit and hospital length of stay did not change.

CONCLUSIONS

We demonstrated a reduction in SWI rates after implementing an SWI prevention bundle including standardized surgical closure and prolonged wound protection.

Rates and Determinants of Hospital-Acquired Infection among ICU Patients Undergoing Cardiac Surgery in Developing Countries: Results from EMERGENCY'NGO's Hospital in Sudan

Introduction. Knowledge of local and regional antimicrobial resistance (AMR) is crucial in clinical decision-making, especially with critically ill patients. The aim of this study was to investigate the rate and pattern of infections in valvular heart disease patients admitted to the intensive care unit (ICU) at the Salam Centre for Cardiac Surgery in Khartoum, Sudan (run by EMERGENCY NGO). Methods. This is a retrospective, observational study from a single, large international referral centre (part of a Regional Programme), which enrolled patients admitted to the ICU between 1 January and 31 December 2019. Data collected for each patient included demographic data, operating theatre/ICU data and microbiological cultures. Results. Over the study period, 611 patients were enrolled (elective surgery n = 491, urgent surgery n = 34 and urgent medical care n = 86). The infection rate was 14.2% and turned out to be higher in medical than in surgical patients (25.6% vs. 12.4%; p = 0.002; OR = 2.43) and higher in those undergoing urgent surgery than those undergoing elective (29.4% vs. 11.2%; p = 0.004; OR = 3.3). Infection was related to (a) SOFA score (p < 0.001), (b) ICU length of stay (p < 0.001) and (c) days from ICU admission to OT (p = 0.003). A significant relationship between the type of admission (elective, urgent surgery or medical) and the presence of infections was found (p < 0.001). The mortality rate was higher among infected patients (infected vs. infection-free: 10.3% vs. 2.1%; p < 0.001; OR = 5.38; 95% CI: 2.16−13.4; p < 0.001). Conclusions. Hospital-acquired infections remain a relevant preventable cause of mortality in our particular population.

Establishment and Validation of a Nomogram to Predict Hospital-Acquired Infection in Elderly Patients After Cardiac Surgery

Background

Hospital-acquired infection (HAI) after cardiac surgery is a common clinical concern associated with adverse prognosis and mortality. The objective of this study is to determine the prevalence of HAI and its associated risk factors in elderly patients following cardiac surgery and to build a nomogram as a predictive model.

Methods

We developed and internally validated a predictive model from a retrospective cohort of 6405 patients aged ≥70 years, who were admitted to our hospital and underwent cardiac surgery. The primary outcome was HAI. Multivariable logistic regression analysis was used to identify independent factors significantly associated with HAI. The performance of the established nomogram was assessed by calibration, discrimination, and clinical utility. Internal validation was achieved by bootstrap sampling with 1000 repetitions to reduce the overfit bias.

Results

Independent factors derived from the multivariable analysis to predict HAI were smoking, myocardial infarction, cardiopulmonary bypass use, intraoperative erythrocytes transfusion, extended preoperative hospitalization days and prolonged duration of mechanical ventilation postoperatively. The derivation model showed good discrimination, with a C-index of 0.706 [95% confidence interval 0.671–0.740], and good calibration [Hosmer–Lemeshow test P = 0.139]. Internal validation also maintained optimal discrimination and calibration. The decision curve analysis revealed that the nomogram was clinically useful.

Conclusions

We developed a predictive nomogram for postoperative HAIs based on routinely available data. This predictive tool may enable clinicians to achieve better perioperative management for elderly patients undergoing cardiac surgery but still requires further external validation.

The Epidemiology and Pathogenesis and Treatment of Pseudomonas aeruginosa Infections: An Update

Pseudomonas aeruginosa is a Gram-negative bacterial pathogen that is a common cause of nosocomial infections, particularly pneumonia, infection in immunocompromised hosts, and in those with structural lung disease such as cystic fibrosis. Epidemiological studies have identified increasing trends of antimicrobial resistance, including multi-drug resistant (MDR) isolates in recent years. P. aeruginosa has several virulence mechanisms that increase its ability to cause severe infections, such as secreted toxins, quorum sensing and biofilm formation. Management of P. aeruginosa infections focuses on prevention when possible, obtaining cultures, and prompt initiation of antimicrobial therapy, occasionally with combination therapy depending on the clinical scenario to ensure activity against P. aeruginosa. Newer anti-pseudomonal antibiotics are available and are increasingly being used in the management of MDR P. aeruginosa.

Diagnosis of infection after cardiovascular surgery (DICS): a study protocol for developing and validating a prediction model in prospective observational study

INTRODUCTION

Postoperative infection (PI) is one of the main severe complications after cardiovascular surgery. Therefore, antibiotics are routinely used during the first 48 hours after cardiovascular surgery. However, there is no effective method for early diagnosis of infection after cardiovascular surgery, particularly, to determine whether postoperative patients need to prolong the use of antibiotics after the first 48 hours. In this study, we aim to develop and validate a diagnostic model to help identify whether a patient has been infected after surgery and guide the appropriate use of antibiotics.

METHODS AND ANALYSIS

In this prospective study, we will develop and validate a diagnostic model to determine whether the patient has a bacterial infection within 48 hours after cardiovascular surgery. Baseline data will be collected through the electronic medical record system. A total of 2700 participants will be recruited (n=2000 for development, n=700 for validation). The primary outcome of the study is the newly PI during the first 48 hours after cardiovascular surgery. Logistic regression penalised with elastic net regularisation will be used for model development and bootstrap and k-fold cross-validation aggregation will be performed for internal validation. The derived model will be also externally validated in patients who are continuously included in another time period (N=700). We will evaluate the calibration and differentiation performance of the model by Hosmer-Lemeshow good of fit test and the area under the curve, respectively. We will report sensitivity, specificity, positive predictive value and negative predictive value in the validation data-set, with a target of 80% sensitivity.

ETHICS AND DISSEMINATION

Ethical approval was obtained from Medical Ethics Committee of Affiliated Nanjing Drum Tower Hospital, Nanjing University Medical College (2020-249-01).

TRIAL REGISTRATION NUMBER

Chinese Clinical Trial Register (www.chictr.org.cn, ChiCTR2000038762); Pre-results.