Risk factors for postoperative pneumonia after cardiac surgery: a prediction model

High-dose inhaled NO for the prevention of nosocomial pneumonia after cardiac surgery under cardiopulmonary bypass: A proof-of-concept prospective randomised study

OBJECTIVE

This study aimed to assess the safety and potential efficacy of high-dose inhaled nitric oxide therapy for the prevention of postoperative pneumonia in cardiac surgery patients.

METHODS

A prospective randomised controlled pilot study included 74 patients with moderate risk of postoperative pneumonia after elective cardiac surgery under cardiopulmonary bypass. Patients were randomised into two groups. The main group (NO-group) (n = 37) received inhaled nitric oxide at a dose of 200 ppm for 30 minutes 2 times a day for 5 days or until pneumonia developed. The control group received conventional postoperative care (n = 37). The primary endpoint was the incidence of postoperative pneumonia during in-hospital stay.

RESULTS

Preventive nitric oxide inhalations were associated with a reduced incidence of postoperative nosocomial pneumonia (2 (5.4%) cases in the main group (NO-group) vs. 9 (24.3%) cases in the control group, p = 0.046; OR = 0.178, 95% CI = 0.036-0.89)). There was no decrease in either peak expiratory flow, or peak inspiratory flow in comparison with the preoperative values in the NO-group. Inhaled nitric oxide therapy is safe. It did not lead to an increase in the incidence of acute kidney injury.

CONCLUSIONS

High-dose inhaled nitric oxide therapy is safe and effective for the prevention of postoperative nosocomial pneumonia in cardiac surgery.

Epidemiology and perioperative factors contributing to postoperative pneumonia in patients undergoing isolated coronary artery bypass grafting: a retrospective Chinese study

BACKGROUND

Despite the existent studies investigating the risk factors for postoperative pneumonia (POP) following coronary artery bypass grafting (CABG), the comprehensive understanding of POP is constrained by the scarcity of epidemiological data.

OBJECTIVE

To investigate the epidemiology and contributing factors of POP in patients undergoing isolated CABG, and establish a prediction model.

DESIGN

A single center, retrospective case-control study.

SETTING

Seven cardiovascular surgery wards across three campuses of a large general hospital in Henan Province, Mid-China.

PARTICIPANTS

Patients aged ≥ 18 years who underwent isolated CABG between January 1, 2020 and November 30, 2023.

METHODS

Univariate and multivariate analyses with restricted cubic splines (RCS) were performed to identify factors that independently contributed to POP and explore the potential nonlinear relationships. The prediction model was evaluated via receiver operating characteristic curve analysis.

RESULTS

POP occurred in 11.34% of patients (518/4569). A total of 416 pathogenic strains were isolated from 381 patients, predominantly Gram-negative bacteria (86.5%). Pathogen distribution varied annually and quarterly. Multivariate analyses indicated that age, diabetes mellitus, smoking, operative duration, red blood cell transfusion, and duration of mechanical ventilation were significantly associated with higher POP risk, whereas higher hemoglobin and total cholesterol levels indicated a reduced likelihood. RCS analysis revealed a nonlinear relationship between operative duration and POP. The prediction model demonstrated a high predictive value (C-statistic: 0.774, 95% CI: 0.735-0.813).

CONCLUSIONS

This study identified eight independent factors that significantly influence the risk of POP following CABG, thereby clarifying the direction for optimizing perioperative prevention strategies for POP.

Risk factors of pneumonia after thoracic aortic surgery

OBJECTIVE

Pneumonia is a common complication and a significant cause of mortality following cardiovascular surgery. This study aimed to investigate the incidence and risk factors for pneumonia after thoracic aortic surgery.

METHODS

A retrospective review was conducted on the medical records of 380 patients who underwent thoracic aortic surgery between January 2016 and December 2019. Patients were classified into pneumonia and non-pneumonia groups based on postoperative outcomes. Pneumonia was further categorized as aspiration pneumonia, ventilation-associated pneumonia (VAP), or other types. Risk factors were identified through univariate and multivariate analyses.

RESULTS

Postoperative pneumonia during hospitalization occurred in 30 patients (7.9 %), including 18 cases of aspiration pneumonia (4.7 %) and 9 cases of VAP (2.4 %). Risk factors identified included hoarseness before surgery, aortic arch replacement, longer anesthesia time, longer intubation duration, necessity for tracheostomy, cerebrovascular disease after surgery, and postoperative recurrent laryngeal nerve paralysis. Multivariate analysis suggested that hoarseness before surgery and the necessity for tracheostomy were independent risk factors for pneumonia during hospitalization.

CONCLUSION

This study identified key risk factors for postoperative pneumonia after thoracic aortic surgery. These findings may aid in identifying high-risk patients and implementing preventive strategies to reduce postoperative pneumonia.

Overlap and correlation of reperfusion lung injury with postoperative pneumonia following pulmonary thromboendarterectomy: incidence, characteristics, and outcomes in chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) can be treated with pulmonary thromboendarterectomy (PTE) which may lead to reperfusion lung injury (RPLI) and postoperative pneumonia. We aimed to describe the incidence, diagnostic characteristics, and clinical outcomes of post-PTE pneumonia compared to RPLI. A retrospective study involving CTEPH subjects who underwent PTE at a large referral center was conducted. Data included demographics, hemodynamics, microbiologic diagnostics, and clinical outcomes. Post-PTE pneumonia was diagnosed based on documentation, signs/symptoms, or microbiologic sampling within seven days of surgery. Among 75 PTE subjects, 21 (28%) had RPLI, and 18 (24%) had post-PTE pneumonia. Of those with RPLI, 48% had pneumonia, suggesting overlap. Eight of 75 (11%) subjects underwent bronchoscopic sampling, and five (63%) samples yielded positive results indicative of infection. Subjects with post-PTE pneumonia and RPLI had longer hospital and ICU lengths of stay and mechanical ventilation duration than either group alone. Post-PTE pneumonia is prevalent and overlaps with RPLI in CTEPH subjects. The study highlights the importance of systematic evaluation and early detection of pneumonia in subjects with RPLI post-PTE. Timely diagnosis and management of pneumonia may improve outcomes. Further research is needed to understand risk factors and develop preventive strategies for post-PTE pneumonia.

A systematic review of cardiac surgery clinical prediction models that include intra-operative variables

BACKGROUND

Most cardiac surgery clinical prediction models (CPMs) are developed using pre-operative variables to predict post-operative outcomes. Some CPMs are developed with intra-operative variables, but none are widely used. The objective of this systematic review was to identify CPMs with intra-operative variables that predict short-term outcomes following adult cardiac surgery.

METHODS

Ovid MEDLINE and EMBASE databases were searched from inception to December 2022, for studies developing a CPM with at least one intra-operative variable. Data were extracted using a critical appraisal framework and bias assessment tool. Model performance was analysed using discrimination and calibration measures.

RESULTS

A total of 24 models were identified. Frequent predicted outcomes were acute kidney injury (9/24 studies) and peri-operative mortality (6/24 studies). Frequent pre-operative variables were age (18/24 studies) and creatinine/eGFR (18/24 studies). Common intra-operative variables were cardiopulmonary bypass time (16/24 studies) and transfusion (13/24 studies). Model discrimination was acceptable for all internally validated models (AUC 0.69-0.91). Calibration was poor (15/24 studies) or unreported (8/24 studies). Most CPMs were at a high or indeterminate risk of bias (23/24 models). The added value of intra-operative variables was assessed in six studies with statistically significantly improved discrimination demonstrated in two.

CONCLUSION

Weak reporting and methodological limitations may restrict wider applicability and adoption of existing CPMs that include intra-operative variables. There is some evidence that CPM discrimination is improved with the addition of intra-operative variables. Further work is required to understand the role of intra-operative CPMs in the management of cardiac surgery patients.

Dobutamine, Epinephrine, and Milrinone Accelerate Particle Transport Velocity in Murine Tracheal Epithelium via Ca2+ Release from Caffeine-Sensitive Internal Stores

Mucociliary clearance, the ability of the respiratory tract to protect the integrity of the airways through the mechanical removal of potentially harmful substances, is of enormous importance during intensive care treatment. The present study aimed to evaluate the influence of clinically relevant inotropic agents on mucociliary clearance. The particle transport velocity (PTV) of isolated murine tracheae was measured as a surrogate for mucociliary clearance in the presence of dobutamine, epinephrine, and milrinone. Inhibitory substances were applied to elucidate the signal transduction cascades and the value and origin of calcium ions which provoke alterations in mucociliary clearance function. Dobutamine, epinephrine, and milrinone increased the PTV in a dose-dependent manner with half maximal effective concentrations of 75.7 nM, 87.0 nM, and 13.7 µM, respectively. After the depletion of intracellular calcium stores, no increase in PTV was observed after administering any of the three inotropic agents. While dobutamine and epinephrine activated β-adrenergic receptors, epinephrine used both the phospholipase C (PLC) and protein kinase A (PKA) pathway to promote the release of intracellular Ca2+. However, dobutamine primarily acted on the PKA pathway, having only a minor influence on the PLC pathway. The induced changes in PTV following milrinone administration required both the PKA and PLC pathway, although the PKA pathway was responsible for most of the induced changes. In conclusion, the common inotropic agents dobutamine, epinephrine, and milrinone increase murine PTV in a concentration-dependent manner and ultimately release Ca2+ from intracellular calcium stores, suggesting the function of changes in mucociliary clearance in the respiratory tract.

Effect of metagenomic next-generation sequencing on clinical outcomes in adults with severe pneumonia post-cardiac surgery: a single-center retrospective study

Reports on the application of metagenomic next-generation sequencing (mNGS) in adult patients with severe pneumonia after cardiac surgery remain limited. This study aimed to evaluate the clinical outcomes of mNGS analysis of bronchoalveolar lavage fluid (BALF) in such patients.A retrospective cohort study was conducted on adult patients with severe pneumonia after cardiac surgery. Samples were collected from patients in the surgical intensive care unit (SICU) of Sichuan Provincial People's Hospital between January 2019 and March 2024. Upon diagnosis of severe pneumonia, bronchoalveolar lavage fluid was obtained via bronchoscopy within 24 h. The mNGS group was composed of patients tested using mNGS and conventional microbiological tests. BALF was detected only by the conventional microbiological test (CMT) method in the CMT group, which involved examining bacterial and fungal smears and cultures at least. We reviewed a total of 4,064 cardiac surgeries, and based on the inclusion criteria, a total of 113 adult patients with severe pneumonia after cardiac surgery were included in this study. The overall positive rate detected by mNGS was significantly higher than that of the culture method (98% vs. 58%, P<0.0001). After receipt of the microbiological results, the mNGS group exhibited a higher incidence of antibiotic adjustments in comparison to the CMT group (P = 0.0021). After adjusting the treatment plan based on microbial testing results, the mNGS group showed an improvement in ventilator-free days within 28 days (P = 0.0475), with a shorter duration of invasive ventilation compared to the CMT group (P = 0.0208). The detection of mNGS can significantly improve the Acute Physiology and Chronic Health Evaluation-II (APACHE II) score (P = 0.0161) and Sequential Organ Failure Assessment (SOFA) score (P = 0.0076) on the 7th day after admission to the SICU. In this study, the mNGS group showed signs of having a positive impact on the length of stay in ICU (median: 9 days, IQR: 7-10 days vs. median: 10 days, IQR: 8-13.75 days, P = 0.0538), length of stay in Hospital (median: 20 days, IQR: 17-28 days vs. median: 25 days, IQR: 18-29 days, P = 0.1558), mortality in 28 days (19% vs. 20%, P = 0.8794), in-hospital mortality (19% vs. 22%, P = 0.7123); however, statistical analysis did not confirm these differences to be significant. mNGS could serve as a valuable complement to conventional diagnostic approaches in adult patients with severe pneumonia after cardiac surgery, potentially improving diagnostic accuracy and leading to more precise and timely interventions, with significant potential to inform clinical decision-making and enhance patient outcomes.

Safety and efficacy of a novel quantitative phase I exercise in patients after cardiopulmonary bypass: a single-blind, prospective, non-randomized study

Background

Despite the positive effect of early post-cardiac surgery exercises, the concern of safety issues is high, indicating the need for standardized and quantitative mobility indicators to enhance early mobilization monitoring in the intensive care unit while ensuring patient safety. This study aimed to compare the safety and efficacy of quantitative phase I exercise versus usual care in patients who have undergone cardiac surgery.

Methods

In this non-randomized, single-blind trial, patients following on-pump cardiac surgery were allocated to either quantitative exercise (intervention group, n=114) or usual care (control group, n=114) based on their willingness. Continuous cycling ergometer was used for intervention, and the peak power was recorded for setting next exercise intensity. Noninvasive cardiac output monitoring during exercise was used for safety management. Patients received one time per day, seven sessions in total.

Results

Two-way repeated-measure analysis of variance demonstrated significant group and test time difference for forced expiratory volume in 1 s (FEV1) (P=0.01), maximum expiratory pressure (MEP) (P=0.02), peak expiratory flow (PEF) rate (P=0.045), and 6-minute walking distance (6MWD) (P=0.001); more improvement of 6MWD in intervention group (P<0.001). Intervention group showed significant post-test improvements except FEV1/forced vital capacity (FVC). Post-test differences between groups were observed in FEV1 (P=0.02), FVC (P=0.02), MEP (P=0.02), 6MWD (P<0.001), and △6MWD (P<0.001). Analysis of covariance with smoking as covariate showed consistent results. Postoperative stay in intensive-care unit in the intervention group [mean ± standard deviation (SD), 3.0±1.3] was shorter than that in the control group (mean ± SD, 3.5±2.2) (P=0.03).

Conclusions

Quantitative phase I exercise applied to patients following cardiopulmonary bypass is safe and recovers respiratory and physical capacity more quickly.

Incidence of postoperative pneumonia in various surgical subspecialties: a retrospective study

Postoperative pneumonia (POP) can be defined as either hospital-acquired pneumonia (HAP, pneumonia developing 48-72 h after admission) or ventilator-associated pneumonia (VAP, pneumonia developing 48-72 h after endotracheal intubation)' or within 30 days in postoperative patients. POP accounts for 2.7-3.4% of postoperative complications. Few studies have evaluated the incidence and the risk factors of POP. This study aimed to estimate the incidence of POP and identify the predictive factors of POP in King Abdul-Aziz University Hospital (KAUH), Jeddah, Saudi Arabia. This retrospective record review included all patients diagnosed with POP at KAUH between 2011 and 2021. Patients younger than 18 years of age and those diagnosed with congenital heart or lung disease were excluded from the study. Data were analyzed using the SPSS program version 26. Of the 2350 patients, 236 met the inclusion criteria. The mean age of patients was 58.12± 17.66 years; 82.6% had comorbidities. ENT (6.4%) and cardiothoracic surgeries associated with POP were the most common surgeries (4.2%). Comorbidities were found as an independent predictor of pneumonia among the studied patients (P = 0.024). The incidence of developing POP was (19.9%). Therefore, Physicians should be aware of POP. Especially when treating patients with comorbidities and patients on corticosteroids.

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.

Analyzing Pre-operative Hospital Stay and Incidence of Hospital Acquired Infection: A Retrospective Study

Background and objectives

Healthcare-associated infections (HCAIs) pose a significant challenge, impacting patient safety and treatment effectiveness. This retrospective study investigates the correlation between pre-operative hospital stays and HCAIs in ICU cardiac surgery patients.

Materials and methods

Medical records of 35 patients who died post-cardiac surgery in the ICU were analyzed, focusing on the duration of pre-operative hospitalization.

Results

Prolonged pre-operative stays strongly correlate (r = 0.993) with increased HCAIs, indicating a critical risk factor.

Conclusions

The duration of pre-operative hospital stays is pivotal in HCAI risk. Prospective multicenter studies are needed for validation, which is crucial for enhancing patient safety and treatment efficacy.

Study on risk factors and treatment strategies of hypoxemia after acute type a aortic dissection surgery

Acute type A aortic dissection is a life-threatening cardiovascular disease characterized by rapid onset and high mortality. Emergency surgery is the preferred and reliable treatment option. However, postoperative complications significantly impact patient prognosis. Hypoxemia, a common complication, poses challenges in clinical treatment, negatively affecting patient outcomes and increasing the risk of mortality. Therefore, it is crucial to study and comprehend the risk factors and treatment strategies for hypoxemia following acute type A aortic dissection to facilitate early intervention.

Effects of quality nursing on the surgical site wound infections in patients undergoing cardiothoracic surgery: A meta-analysis

The aim of this study is to systematically evaluate the effects of quality nursing on wound infections and postoperative complications in patients undergoing cardiothoracic surgery. Computerised searches of the PubMed, Web of Science, Cochrane Library, Embase, China Biomedical Literature Database, China National Knowledge Infrastructure and Wanfang databases were conducted from database inception to October 2023 for randomised controlled trials (RCTs) on the application of quality nursing to patients undergoing cardiothoracic surgery. The studies were screened and evaluated by two researchers based on the inclusion and exclusion criteria, and data were extracted from the included studies. Stata software (version 17.0) was used for all analyses performed. A total of 18 RCTs and 1742 patients were included, including 972 in the quality nursing group and 870 in the routine nursing group. The analysis revealed that compared with routine nursing, patients undergoing cardiothoracic surgery who received quality nursing care were significantly less likely to experience postoperative wound infections (OR = 0.31, 95% CI: 0.19-0.51, p < 0.001) and complications (OR = 0.24. 95% CI: 0.17-0.33, p < 0.001). The implementation of quality nursing in clinical care after cardiothoracic surgery can effectively reduce the incidence of wound infections and postoperative complications, and is worthy of promotion and clinical application.

Deep Learning-Based Computer-Aided Detection System for Preoperative Chest Radiographs to Predict Postoperative Pneumonia

RATIONALE AND OBJECTIVES

The role of preoperative chest radiography (CR) for prediction of postoperative pneumonia remains uncertain. We aimed to develop and validate a prediction model for postoperative pneumonia incorporating findings of preoperative CRs evaluated by a deep learning-based computer-aided detection (DL-CAD) system MATERIALS AND METHODS: This retrospective study included consecutive patients who underwent surgery between January 2019 and March 2020 and divided into development (surgery in 2019) and validation (surgery between January and March 2020) cohorts. Preoperative CRs obtained within 1-month before surgery were analyzed with a commercialized DL-CAD that provided probability values for the presence of 10 different abnormalities in CRs. Logistic regression models to predict postoperative pneumonia were built using clinical variables (clinical model), and both clinical variables and DL-CAD results for preoperative CRs (DL-CAD model). The discriminative performances of the models were evaluated by area under the receiver operating characteristic curves.

RESULTS

In development cohort (n = 19,349; mean age, 57 years; 11,392 men), DL-CAD results for pulmonary nodules (odds ratio [OR, for 1% increase in probability value], 1.007; p = 0.021), consolidation (OR, 1.019; p < 0.001), and cardiomegaly (OR, 1.013; p < 0.001) were independent predictors of postoperative pneumonia and were included in the DL-CAD model. In validation cohort (n = 4957; mean age, 56 years; 2848 men), the DL-CAD model exhibited a higher AUROC than the clinical model (0.843 vs. 0.815; p = 0.012).

CONCLUSION

Abnormalities in preoperative CRs evaluated by a DL-CAD were independent risk factors for postoperative pneumonia. Using DL-CAD results for preoperative CRs led to an improved prediction of postoperative pneumonia.

Risk Factors of Postoperative Hospital-Acquired Pneumonia in Patients Undergoing Cardiac Surgery

Background and Objectives. Hospital-acquired pneumonia is one of the complications that may occur in the postoperative period in patients undergoing heart valve surgery, which may result in prolonged hospitalization, development of respiratory failure requiring mechanical ventilation or even death. This study investigated the preoperative risk factors of postoperative pneumonia after heart valve surgery. Materials and Methods: This was a prospective study in a group of consecutive patients with hemodynamically significant valvular heart disease undergoing valve surgery. The primary endpoint at the in-hospital follow-up was hospital-acquired pneumonia after heart valve surgery. Logistic regression analysis was used to assess which variables were predictive of the primary endpoint, and odds ratios (ORdis) were calculated with a 95% confidence interval (CI). Multivariate analysis was based on the results of single-factor logistic regression, i.e., in further steps all statistically significant variables were taken into consideration. Results: The present study included 505 patients. Postoperative pneumonia occurred in 23 patients. The mean time to diagnosis of pneumonia was approximately 3 days after heart valve surgery (±2 days). In multivariate analysis, preoperative level of high-sensitivity Troponin T (hs-TnT) (OR 2.086; 95% CI 1.211-3.593; p = 0.008) and right ventricular systolic pressure (RVSP) (OR 1.043; 95% CI 1.018-1.067; p 0.004) remained independent predictors of the postoperative pneumonia. Of the patients with postoperative pneumonia, 3 patients died due to the development of multiple organ dysfunction syndrome (MODS). Conclusions: Preoperative determination of serum hs-TnT concentration and echocardiographic measurement of the RVSP parameter may be useful in predicting postoperative pneumonia in patients undergoing heart valve surgery.

Postoperative pulmonary complications in patients undergoing aortic surgery: A single-center retrospective study

Postoperative pulmonary complications (PPCs) are among the most common complications after cardiovascular surgery. This study aimed to explore the real incidence of and risk factors for PPC in patients with acute type A aortic dissection (ATAAD) who underwent total aortic arch replacement combined with the frozen elephant trunk (TAR + FET). In total, 305 ATAAD patients undergoing TAR + FET from January 2021 to August 2022 in a single-center were divided into PPCs or non-PPCs group. The incidence of PPCs was calculated, risk factors of PPCs were analyzed, and postoperative outcomes were compared between these 2 groups. The incidence of any PPC was 29.2%. And the incidence of respiratory infection, respiratory failure, pleural effusion, atelectasis, pneumothorax, acute respiratory distress syndrome, aspiration pneumonitis, pulmonary edema and bronchospasm was 23.0%, 12.5%, 10.5%, 1.0%, 0.7%, 1.0%, 0%, 0.7%, 0%, respectively. The logistic regression analysis revealed that the history of diabetes, history of renal dysfunction, preoperative SpO2 <90%, cardiopulmonary bypass duration, fresh frozen plasma volume and platelet concentrates volume were independent risk factors for PPCs. Among 2 groups, postoperative ventilation duration, postoperative length of stay in intensive care unit and hospital were (73.5 ± 79.0 vs 24.8 ± 35.2 hours; P < .001), (228.3 ± 151.2 vs 95.2 ± 72.0 hours; P < .001) and (17.9 ± 8.8 vs 11.5 ± 6.2 days; P < .001). There was no difference between 2 groups of in-hospital mortality rate. Additionally, other short-term outcomes were also significantly poorer in patients with PPCs. PPCs are common in ATAAD patients undergoing TAR + FET, and could be multifactorial. PPCs occurrence are associated with poor patient outcomes postoperatively and worth further investigation.

Association between admission hyperglycemia and postoperative pneumonia in geriatric patients with hip fractures

BACKGROUND

Admission hyperglycemia is a common phenomenon in the early stages of injury. This study aimed to determine the relationship between admission hyperglycemia and postoperative pneumonia in geriatric patients with hip fractures.

METHODS

A total of 600 geriatric patients admitted to Dandong Central Hospital with hip fractures were included. Patients were divided into four groups based on quartiles of admission blood glucose levels: Q1- Q4. Multivariable logistic regression and propensity score-matched analyses were conducted to calculate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for postoperative pneumonia. Receiver operating characteristic (ROC) curves were used to determine the cut-off value of admission hyperglycemia for predicting postoperative pneumonia.

RESULTS

The incidence of postoperative pneumonia was significantly higher among hyperglycemic patients than those with normal glucose levels (OR = 2.090, 95% CI: 1.135-3.846, p = 0.016). Admission hyperglycemia showed moderate predictive power, with an area under the ROC curve of 0.803. Furthermore, propensity score-matched analyses demonstrated that patients in the Q3 (OR = 4.250, 95% CI: 1.361-13.272, p = 0.013) and Q4 (OR = 4.667, 95% CI: 1.251-17.405, p = 0.022) quartiles had a significantly higher risk of postoperative pneumonia compared to patients in the Q1 quartile.

CONCLUSIONS

Admission hyperglycemia in elderly hip fracture patients increases the risk of postoperative pneumonia. This biomarker can aid clinical assessment and perioperative management.

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).

The Impact of Left Ventricular Diastolic Dysfunction on Respiratory Adverse Events in Cardiac Surgery Patients-An Observational Prospective Single-Center Study

BACKGROUND

Left ventricular diastolic dysfunction (LV DD) is the most dominant cause of heart failure with preserved ejection fraction (HFpEF) worldwide. This pathological condition may contribute to postcapillary pulmonary hypertension (pcPH) development. Hypoxemia, often observed in pcPH, may significantly negatively impact the course of hospitalization in patients after cardiac surgery. The aim of our study was to investigate the impact of LV DD on the frequency of postoperative respiratory adverse events (RAE) in patients undergoing Coronary Artery Bypass Grafting (CABG).

METHODS

The left ventricular (LV) diastolic function was assessed in 56 consecutive patients admitted for CABG. We investigated the relationship between LV DD and postoperative respiratory adverse events (RAE) in groups with normal LV diastolic function and LV DD stage I, II, and III.

RESULTS

Left ventricular diastolic dysfunction stage I was observed in 11 patients (19.6%) and LV DD stage II or III in 19 patients (33.9%). Arterial blood partial pressure of oxygen (PaO2) to the fraction of inspired oxygen (FiO2) index during postoperative mechanical ventilation was significantly lower in LV DD stage II or III than in the group with normal LV diastolic function. Patients with DD stage II or III had a higher occurrence of postoperative pneumonia than the group with normal LV diastolic function.

CONCLUSIONS

Left ventricular diastolic dysfunction is widespread in cardiac surgery patients and is an independent risk factor for lower minimal PaO2/FiO2 index during mechanical ventilation and higher occurrence of pneumonia.

The effects of plasma to red blood cells transfusion ratio on in-hospital mortality in patients with acute type A aortic dissection

Background

Blood transfusion is a frequent and necessary practice in acute type A aortic dissection (AAAD) patients, but the effect of plasma/red blood cells (RBCs) ratio on mortality remains unclear. The aim of this study is to investigate the association between plasma/RBCs transfusion ratio and in-hospital mortality in patients with AAAD.

Methods

Patients were admitted to Xiangya Hospital of Central South University from January 1, 2016 to December 31, 2021. Clinical parameters were recorded. Multivariate Cox regression model was used to analyze the association between transfusion and in-hospital mortality. We used the smooth curve fitting and segmented regression model to assess the threshold effect between plasma/RBCs transfusion ratio and in-hospital mortality in patients with AAAD.

Results

The volumes of RBCs [14.00 (10.12-20.50) unit] and plasma [19.25 (14.72-28.15) unit] transfused in non-survivors were significantly higher than in survivors [RBCs: 8.00 (5.50-12.00) unit]; plasma: [10.35 (6.50-15.22) unit]. Multivariate Cox regression analysis showed plasma transfusion was an independent risk factor of in-hospital mortality. Adjusted HR was 1.03 (95% CI: 0.96-1.11) for RBCs transfusion and 1.08 (95% CI: 1.03-1.13) for plasma transfusion. In the spline smoothing plot, mortality risk increased with plasma/RBCs transfusion ratio leveling up to the turning point 1. Optimal plasma/RBCs transfusion ratio with least mortality risk was 1. When the plasma/RBCs ratio was <1 (adjusted HR per 0.1 ratio: 0.28, 95% CI per 0.1 ratio: 0.17-0.45), mortality risk decreased with the increase of ratio. When the plasma/RBCs ratio was 1-1.5 (adjusted HR per 0.1 ratio: 2.73, 95% CI per 0.1 ratio:1.13-6.62), mortality risk increased rapidly with the increase of ratio. When the plasma/RBCs ratio was >1.5 (adjusted HR per 0.1 ratio: 1.09, 95% CI per 0.1 ratio:0.97-1.23), mortality risk tended to reach saturation, and increased non-significantly with the increase of ratio.

Conclusion

A 1:1 plasma/RBCs ratio was associated with the lowest mortality in the patients with AAAD. And non-linear relationship existed between plasma/RBCs ratio and mortality.

Comparison of Tools for Postoperative Pulmonary Complications After Cardiac Surgery

OBJECTIVES

To review the efficacy of 2 score tools for identifying pulmonary complications after cardiac surgery.

DESIGN

A retrospective observational study.

SETTING

At the West China Hospital of Sichuan University General Hospital.

PARTICIPANTS

Patients who underwent elective cardiac surgery (N = 508).

INTERVENTIONS

Not applicable.

MEASUREMENTS AND MAIN RESULTS

A total of 508 patients who underwent elective cardiac surgery between March 2021 and December 2021 were included in this observational study. Three independent physiotherapists used 2 different sets of score tools, as described by Kroenke et al. (Kroenke Score) and Reeve et al. (Melbourne Group Scale), to evaluate clinically defined pulmonary complications according to the European Perioperative Clinical Outcome definitions (including atelectasis, pneumonia, and respiratory failure) daily after surgery at midday. The incidence of postoperative pulmonary complications (PPCs) was 51.6% (262/508) with the Kroenke Score and 21.9% (111/508) with the Melbourne Group Scale. The clinically observed incidence of atelectasis was 51.4%, pneumonia was 20.9%, and respiratory failure at 6.5%. The receiver operator characteristics curve showed that the overall validity of the Kroenke Score was better than that of the Melbourne Group Scale in atelectasis (area under the curve [AUC], 91.5% v 71.3%). The Melbourne Group Scale performed better in pneumonia (AUC, 99.4% v 80.0%) and respiratory failure (AUC, 88.5% v 75.9%) than the Kroenke Score.

CONCLUSION

The incidence of PPCs after cardiac surgery was highly prevalent. Both the Kroenke Score and the Melbourne Group Scale are effective in identifying patients with PPCs. Kroenke Score can identify patients with mild pulmonary adverse events, whereas the Melbourne Group Scale is more dominant in identifying moderate-to-severe pulmonary complications.

Retrospective Evaluation of Fascial Plane Blocks in Cardiac Surgery With Median Sternotomy in a Tertiary Hospital

BACKGROUND AND AIM

Cardiac surgery typically causes moderate to severe postoperative pain and discomfort. Inadequate pain management in the early postoperative period leads to pulmonary complications. The length of intensive care unit (ICU) stay and the hospital is typically prolonged. As a component of multimodal analgesia regimens, fascial plane blocks have become more popular. In our clinic, serratus anterior plane blocks (SAPB), pectoral nerve blocks (PECS I-II), and pectointercostal nerve fascial plane blocks (PIFB) are performed by ultrasonography. We wished to evaluate the postoperative visual pain scale, initial additional analgesic agent requirement time, extubation time, morbidity and mortality in patients who underwent open heart surgery with fascial plane blocks.

MATERIALS AND METHODS

Forty-eight patients over 18 years who underwent open heart surgery with sternotomy between 01 September 2021 and 15 June 2022 were evaluated retrospectively. Only patients with chest wall blocks placed at the end of surgery were included in the study. In Group 1, the PECS II block was placed on the chest tube side and bilateral PIFBs were placed at the end of surgery in the operating room. In Group 2, SAPB was placed on the chest tube side and bilateral PIFBs were placed at the end of surgery. Data regarding patient demographics, anesthesia method applied, amount of opioid used intraoperatively, cardiopulmonary bypass time, anesthesia and surgery time, postoperative extubation time, mechanical ventilation time, Visual Analogue Scale (VAS) of patients at rest and movement at 6th, 12th, 18th, 24th, 48th hours post-extubation, time to and type of first postoperative analgesic, postoperative complications, length of cardiac intensive care unit (CICU) stay and hospital length of stay were recorded from hospital records.

RESULTS

 The data of a total of 46 patients (Group 1: PECS II block + PIFB, n=20; Group 2: SAPB+ PIFB, n=26) were analyzed retrospectively. There was no difference in demographic variables between the groups. Intraoperative opioid usage, operation time, Cardiopulmonary bypass time, postoperative mechanical ventilation time, extubation time, ICU discharge time, and length of hospital stay were not statistically different between the groups. The first rescue analgesic requirement time was longer in group 2 than in group 1 but not statistically significant (18.76±15.36 h vs 12.62±10.61 h, p=0.162). The post-extubation VAS scores at rest and movement at the 6th hour were significantly lower in group 2 than in group 1 (1.73±1.28 vs 3.15±2.10, respectively, p=0.02).

CONCLUSION

In our study, the VAS scores at the 6th hour were lower in SAPB + PIFB group than in PECS II + PIFB group. As these blocks can be easy to apply, we thought these combinations could be an alternative for pain relief in cardiac surgery. Prospective randomized studies are needed with a large number of patients.

Nomogram and Risk Calculator for Postoperative Tracheostomy after Heart Valve Surgery

Postoperative tracheostomy (POT) is an important indicator of critical illness, associated with poorer prognoses and increased medical burdens. However, studies on POTs after heart valve surgery (HVS) have not been reported. The objectives of this study were first to identify the risk factors and develop a risk prediction model for POTs after HVS, and second to clarify the relationship between POTs and clinical outcomes. Consecutive adults undergoing HVS from January 2016 to December 2019 in a single cardiovascular center were enrolled, and a POT was performed in 1.8% of the included patients (68/3853). Compared to patients without POTs, the patients with POTs had higher rates of readmission to the ICU and in-hospital mortality, as well as longer ICU and hospital stays. Five factors were identified to be significantly associated with POTs after HVS by our multivariate analysis, including age, diabetes mellitus, pulmonary edema, intraoperative transfusion of red blood cells, and surgical types. A nomogram and a risk calculator were constructed based on the five factors, showing excellent discrimination, calibration, and clinical utility. Three risk intervals were defined as low-, medium-, and high-risk groups according to the nomogram and clinical practice. The findings of this study may be helpful for early risk assessment and perioperative management.

Fulminant psudeumonas pneumonia following coronary artery bypass grafting - Case report

INTRODUCTION AND IMPORTANCE

Pneumonia has always been a source of complication after surgeries. Pseudomonas aeruginosa has emerged as one of the most problematic Gram-negative pathogens among nosocomial infections. Pneumonia caused by pseudomonas is usually slowly progressive allowing clinicians to detect and manage it on time.

CLINICAL PRESENTATION

A 55-year-old man was hospitalized for elective CABG, complicated by fulminant pneumonia. Vancomycin and meropenem were adminestered as soon as the symptoms appeared. However, the patient died from septic shock syndrome caused by pseudomonas pneumonia on the third postoperative day, just hours after the first symptom appeared. The chest X-ray showed an extreme opacity within less than 12 h.

CLINICAL DISCUSSION

This case is reported because of its rare clinical presentation of Fulminant pseudomonas pneumonia following cardiac surgery.

CONCLUSION

Consider pseudomonas aeruginosa as a certain cause of pneumonia after cardiac surgery, and an organized, modified guideline is needed to determine the best option and timeline for treating this complication.

Echocardiographic Probability of Pulmonary Hypertension in Cardiac Surgery Patients—Occurrence and Association with Respiratory Adverse Events—An Observational Prospective Single-Center Study

Background: Pulmonary hypertension (PH) is an independent risk factor of increased morbidity and mortality in cardiac surgery patients (CS). The most common cause underlying PH is left ventricular (LV) diastolic dysfunction. This study aimed to evaluate the echocardiographic probability of PH in patients undergoing CS and its correlation with postoperative respiratory adverse events (RAE). Methods: The echocardiographic probability of PH and its correlation with LV diastolic dysfunction was assessed in 56 consecutive adult patients who were qualified for coronary artery bypass grafting (CABG). Later, the postoperative RAE (such as pneumonia, pulmonary congestion, or hypoxemia), the length of intensive care unit (ICU) treatment and mortality in groups with moderate or high (PH-m/h) and low (PH-l) probability of pulmonary hypertension were examined. Results: PH-m/h was observed in 29 patients, of whom 65.5 % had LV diastolic dysfunction stage II or III. A significantly higher occurrence of RAE was observed in the PH-m/h group as compared to the PH-l group. There were no differences between the PH-m/h and PH-l patient groups regarding the in-hospital length of stay or mortality. Conclusions: High or intermediate probability of PH is common in cardiac surgical patients with left ventricular diastolic dysfunction and correlates with respiratory adverse events.

Nosocomial Extracardiac Infections After Cardiac Surgery

Purpose of Review

Nosocomial extracardiac infections after cardiac surgery are a major public health issue affecting 3–8.2% of patients within 30–60 days following the intervention.

Recent Findings

Here, we have considered the most important postoperative infective complications that, in order of frequency, are pneumonia, surgical site infection, urinary tract infection, and bloodstream infection. The overall picture that emerges shows that they cause a greater perioperative morbidity and mortality with a longer hospitalization time and excess costs. Preventive interventions and corrective measures, diminishing the burden of nosocomial extracardiac infections, may reduce the global costs. A multidisciplinary team may assure a more appropriate management of nosocomial extracardiac infections leading to a reduction of hospitalization time and mortality rate.

Summary

The main and most current data on epidemiology, prevention, microbiology, diagnosis, and management for each one of the most important postoperative infective complications are reported. The establishment of an antimicrobial stewardship in each hospital seems to be, at the moment, the more valid strategy to counteract the challenging problems.

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.

Association Between Early Speech-Language Pathology Consultation and Pneumonia After Cardiac Surgery

PURPOSE

Patients undergoing cardiac surgery are reported to be at higher risk for oropharyngeal dysphagia and aspiration, which may predispose them to respiratory complications such as pneumonia. Speech-language pathology consultation facilitates early identification of swallowing difficulties providing appropriate and timely interventions during the postoperative period. This study explores the association between pneumonia and timing of speech-language pathology order entry and evaluation following cardiac surgery.

METHOD

A retrospective study was performed on adults who underwent cardiac surgery in a tertiary care center, from July 2016 through December 2019. Patients with preexisting tracheostomy upon admission for cardiac surgery were excluded. The medical records of patients who had speech-language pathology consultation orders for swallowing concerns were analyzed in order to compare the timing of speech-language pathology order entry, completion of speech-language pathology evaluation, and incidence of pneumonia during hospitalization following cardiac surgery.

RESULTS

During the study period, 3,168 patients underwent cardiac surgery, of which 2,864 patients met the inclusion criteria. Speech-language pathology was ordered for 473 cases (16.5%), and clinical swallow evaluation (CSE) was completed by speech-language pathology in 419 patients (88.6%), of which 309 patients were suspected to have dysphagia (73.7%). Among the 2,391 patients without speech-language pathology consultation, pneumonia was reported in 34 patients (1.42%). Pneumonia was reported in 53 patients in the speech-language pathology cohort, of which 43 patients (13.9%) were suspected to have dysphagia. Patients with pneumonia had significantly longer median time (20.0 hr, range: 4.9-26.7) from speech-language pathology orders to completion of CSE, compared to those without pneumonia (13.2 hr, range: 3.2-22.4, p = .025). There was no significant difference in the median time from extubation to speech-language pathology consultation order time in patients with pneumonia versus those without pneumonia. Patients with pneumonia were observed to have prolonged, although not statistically significant, median time from extubation to CSE (70.4 hr, range: 21.2-215) compared to those without pneumonia (42.2 hr, range: 19.5-105.8, p = .066).

CONCLUSIONS

Patients without pneumonia in the postoperative period were observed to have shorter median time from extubation to speech-language pathology evaluation. Future studies are needed to further understand the impact of early speech-language pathology consultation and incidence of pneumonia in this population.

Perioperative Exhaled Nitric Oxide as an Indicator for Postoperative Pneumonia in Surgical Lung Cancer Patients: A Prospective Cohort Study Based on 183 Cases

Introduction

This study is conducted to investigate the correlation between perioperative fractional exhaled nitric oxide and postoperative pneumonia (POP) and the feasibility of perioperative FeNO for predicting POP in surgical lung cancer patients.

Methods

Patients who were diagnosed with non-small-cell lung cancer (NSCLC) were prospectively analyzed, and the relationship between perioperative FeNO and POP was evaluated based on patients' basic characteristics and clinical data in the hospital.

Results

There were 218 patients enrolled in this study. Finally, 183 patients were involved in the study, with 19 of them in the POP group and 164 in the non-POP group. The POP group had significantly higher postoperative FeNO (median: 30.0 vs. 19.0 ppb, P < 0.001) as well as change in FeNO (median: 10.0 vs. 0.0 ppb, P < 0.001) before and after the surgery. For predicting POP based on the receiver operating characteristic (ROC) curve, a cutoff value of 25 ppb for postoperative FeNO (Youden's index: 0.515, sensitivity: 78.9%, and specificity: 72.6%) and 4 ppb for change in FeNO (Youden's index: 0.610, sensitivity: 84.2%, specificity: 76.8%) were selected. Furthermore, according to the bivariate regression analysis, FEV1/FVC (OR = 0.948, 95% CI: 0.899–0.999, P=0.048), POD1 FeNO (OR = 1.048, 95% CI: 1.019–1.077, P=0.001), and change in FeNO (OR = 1.087, 95% CI: 1.044–1.132, P < 0.001) were significantly associated with occurrence of POP.

Conclusions

This prospective study revealed that a high postoperative FeNO (>25 ppb), as well as an increased change in FeNO (>4 ppb), may have the potential in detecting the occurrence of POP in surgical lung cancer patients.

Pneumonia After Cardiovascular Surgery: Incidence, Risk Factors and Interventions

Postoperative pneumonia (POP) is prevalent in patients undergoing cardiovascular surgery, associated with poor clinical outcomes, prolonged hospital stay and increased medical costs. This article aims to clarify the incidence, risk factors, and interventions for POP after cardiovascular surgery. A comprehensive literature search was performed to identify previous reports involving POP after cardiovascular surgery. Current situation, predictors and preventive measures on the development of POP were collected and summarized. Many studies showed that POP was prevalent in various cardiovascular surgical types, and predictors varied in different studies, including advanced age, smoking, chronic lung disease, chronic kidney disease, cardiac surgery history, cardiac function, anemia, body mass index, diabetes mellitus, surgical types, cardiopulmonary bypass time, blood transfusion, duration of mechanical ventilation, repeated endotracheal intubation, and some other risk factors. At the same time, several targeted interventions have been widely reported to be effective to reduce the risk of POP and improve prognosis, including preoperative respiratory physiotherapy, oral care and subglottic secretion drainage. Through the review of the current status, risk factors and intervention measures, this article may play an important role in clinical prevention and treatment of POP after cardiovascular surgery.

Preoperative Nomogram and Risk Calculator for Postoperative Hypoxemia and Related Clinical Outcomes Following Stanford Type A Acute Aortic Dissection Surgery

Background

Hypoxemia is a common complication after Stanford type A acute aortic dissection surgery (AADS), however, few studies about hypoxemia after AADS exist. The aims of this study were to identify independent risk factors for hypoxemia after AADS and to clarify its association with clinical outcomes.

Methods

Patients undergoing AADS from 2016 to 2019 in our hospital were identified and used as a training set. Preoperative variables were first screened by univariate analysis and then entered into a multivariate logistic regression analysis to identify independent risk factors. A nomogram and an online risk calculator were constructed based on the logistic model to facilitate clinical practice and was externally validated in an independent dataset.

Results

Severe hypoxemia developed in 119 of the 492 included patients (24.2%) and poorer clinical outcomes were observed in these patients. Five independent risk factors for severe hypoxemia after AADS were identified by multivariate analysis, including older age, smoking history, renal insufficiency, higher body mass index, and white blood cell count. The model showed good calibration, discrimination, and clinical utility in the training set, and was well validated in the validation set. Risk stratification was performed and three risk groups were defined as low, medium, and high risk groups. Hypertension was identified as an independent risk factor for moderate hypoxemia besides the five predictors mentioned above, and renal insufficiency was not significant for mild hypoxemia by multivariate analysis. In addition, although frozen elephant trunk was associated with increased risk of postoperative hypoxemia in the univariate analysis, frozen elephant trunk was also not identified as an independent risk factor for postoperative hypoxemia in the multivariate analysis.

Conclusion

Hypoxemia was frequent following AADS, related to poorer clinical outcomes. Predictors were identified and a nomogram as well as an online risk calculator predicting severe hypoxemia after AADS was developed and validated, which may be helpful for risk estimation and perioperative management.

Nomogram for Postoperative Headache in Adult Patients Undergoing Elective Cardiac Surgery

Background Postoperative headache (POH) is frequent after cardiac surgery; however, few studies on risk factors for POH exist. The aims of the current study were to explore risk factors related to POH after elective cardiac surgery and to establish a predictive system. Methods and Results Adult patients undergoing elective open-heart surgery under cardiopulmonary bypass from 2016 to 2020 in 4 cardiac centers were retrospectively included. Two thirds of the patients were randomly allocated to a training set and one third to a validation set. Predictors for POH were selected by univariate and multivariate analysis. POH developed in 3154 of the 13 440 included patients (23.5%) and the overall mortality rate was 2.3%. Eight independent risk factors for POH after elective cardiac surgery were identified, including female sex, younger age, smoking history, chronic headache history, hypertension, lower left ventricular ejection fraction, longer cardiopulmonary bypass time, and more intraoperative transfusion of red blood cells. A nomogram based on the multivariate model was constructed, with reasonable calibration and discrimination, and was well validated. Decision curve analysis revealed good clinical utility. Finally, 3 risk intervals were divided to better facilitate clinical application. Conclusions A nomogram model for POH after elective cardiac surgery was developed and validated using 8 predictors, which may have potential application value in clinical risk assessment, decision-making, and individualized treatment associated with POH.

Incidence, Risk Factors and Outcomes of Postoperative Headache After Stanford Type a Acute Aortic Dissection Surgery

Background: Postoperative headache (POH) is common in clinical practice, however, no studies about POH after Stanford type A acute aortic dissection surgery (AADS) exist. This study aims to describe the incidence, risk factors and outcomes of POH after AADS, and to construct two prediction models.

Methods: Adults who underwent AADS from 2016 to 2020 in four tertiary hospitals were enrolled. Training and validation sets were randomly assigned according to a 7:3 ratio. Risk factors were identified by univariate and multivariate logistic regression analysis. Nomograms were constructed and validated on the basis of independent predictors.

Results: POH developed in 380 of the 1,476 included patients (25.7%). Poorer outcomes were observed in patients with POH. Eight independent predictors for POH after AADS were identified when both preoperative and intraoperative variables were analyzed, including younger age, female sex, smoking history, chronic headache history, cerebrovascular disease, use of deep hypothermic circulatory arrest, more blood transfusion, and longer cardiopulmonary bypass time. White blood cell and platelet count were also identified as significant predictors when intraoperative variables were excluded from the multivariate analysis. A full nomogram and a preoperative nomogram were constructed based on these independent predictors, both demonstrating good discrimination, calibration, clinical usefulness, and were well validated. Risk stratification was performed and three risk intervals were defined based on the full nomogram and clinical practice.

Conclusions: POH was common after AADS, portending poorer outcomes. Two nomograms predicting POH were developed and validated, which may have clinical utility in risk evaluation, early prevention, and doctor-patient communication.

Development and Validation of Nomogram Models for Postoperative Pneumonia in Adult Patients Undergoing Elective Cardiac Surgery

Background: Postoperative pneumonia (POP) is a frequent complication following cardiac surgery, related to increased morbidity, mortality and healthcare costs. The objectives of this study were to investigate the risk factors associated with POP in adults undergoing elective cardiac surgery and to develop and validate nomogram models.

Methods: We conducted a multicenter retrospective study in four cardiac centers in China. Adults operated with elective open-heart surgery from 2016 to 2020 were included. Patients were randomly allocated to training and validation sets by 7:3 ratio. Demographics, comorbidities, laboratory data, surgical factors, and postoperative outcomes were collected and analyzed. Risk factors for POP were identified by univariate and multivariate analysis. Nomograms were constructed based on the multivariate logistic regression models and were evaluated with calibration, discrimination and decision curve analysis.

Results: A total of 13,380 patients meeting the criteria were included and POP developed in 882 patients (6.6%). The mortality was 2.0%, but it increased significantly in patients with POP (25.1 vs. 0.4%, P < 0.001). Using preoperative and intraoperative variables, we constructed a full nomogram model based on ten independent risk factors and a preoperative nomogram model based on eight preoperative factors. Both nomograms demonstrated good calibration, discrimination, and were well validated. The decision curves indicated significant clinical usefulness. Finally, four risk intervals were defined for better clinical application.

Conclusions: We developed and validated two nomogram models for POP following elective cardiac surgery using preoperative and intraoperative factors, which may be helpful for individualized risk evaluation and prevention decisions.

Clinical risk score for postoperative pneumonia following heart valve surgery

Background:

Postoperative pneumonia (POP) is one of the most common infections following heart valve surgery (HVS) and is associated with a significant increase in morbidity, mortality, and health care costs. This study aimed to identify the major risk factors associated with the occurrence of POP following HVS and to derive and validate a clinical risk score.

Methods:

Adults undergoing open HVS between January 2016 and December 2019 at a single institution were enrolled in this study. Patients were randomly assigned to the derivation and validation sets at 1:1 ratio. A prediction model was developed with multivariable logistic regression analysis in the derivation set. Points were assigned to independent risk factors based on their regression coefficients.

Results:

POP occurred in 316 of the 3853 patients (8.2%). Multivariable analysis identified ten significant predictors for POP in the derivation set, including older age, smoking history, chronic obstructive pulmonary disease, diabetes mellitus, renal insufficiency, poor cardiac function, heart surgery history, longer cardiopulmonary bypass, blood transfusion, and concomitant coronary and/or aortic surgery. A 22-point risk score based on the multivariable model was then generated, demonstrating good discrimination (C-statistic: 0.81), and calibration (Hosmer-Lemeshow χ² = 8.234, P = 0.312). The prediction rule also showed adequate discriminative power (C-statistic: 0.83) and calibration (Hosmer-Lemeshow χ² = 5.606, P = 0.691) in the validation set. Three risk intervals were defined as low-, medium-, and high-risk groups.

Conclusion:

We derived and validated a 22-point risk score for POP following HVS, which may be useful in preventive interventions and risk management.

Trial Registration:

Chictr.org, ChiCTR1900028127; http://www.chictr.org.cn/showproj.aspx?proj=46932