Ventilator-associated pneumonia after cardiac surgery: A meta-analysis and systematic review

Urgent call for attention to diabetes-associated hospital infections

In this editorial, we discuss the recent article by Zhao et al published in the World Journal of Diabetes, which highlights the importance of recognizing the risk indicators associated with diabetes mellitus (DM). Given the severe implications of healthcare-associated infections (HAIs) in hospitalized individuals- such as heightened mortality rates, prolonged hospitalizations, and increased costs- we focus on elucidating the connection between DM and nosocomial infections. Diabetic patients are susceptible to pathogenic bacterial invasion and subsequent infection, with some already harboring co-infections upon admission. Notably, DM is an important risk factor for nosocomial urinary tract infections and surgical site infections, which may indirectly affect the occurrence of nosocomial bloodstream infections, especially in patients with DM with poor glycemic control. Although evidence regarding the impact of DM on healthcare-associated pneumonias remains inconclusive, attention to this potential association is warranted. Hospitalized patients with DM should prioritize meticulous blood glucose management, adherence to standard operating procedures, hand hygiene pra-ctices, environmental disinfection, and rational use of drugs during hospitalization. Further studies are imperative to explore the main risk factors of HAIs in patients with DM, enabling the development of preventative measures and mitigating the occurrence of HAIs in these patients.

Comparative analysis of psychiatric medications and their association with falls and fractures: A systematic review and network meta-analysis

An association between psychiatric medications and falls and fractures in people taking them has been demonstrated, but which class or medication leads to the greatest risk of falls or fractures should be further investigated. The aim of this study was to compare and rank the magnitude of risk of falls and fractures due to different psychiatric medications. Eight databases were searched for this meta-analysis and evaluated using a frequency-based network meta-analysis. The results included a total of 28 papers with 14 medications from 5 major classes, involving 3,467,314 patients. The results showed that atypical antipsychotics were the class of medications with the highest risk of falls, and typical antipsychotics were the class of medications with the highest risk of resulting in fractures. Quetiapine ranked first in the category of 13 medications associated with risk of falls, and class Z drugs ranked first in the category of 6 medications associated with risk of fractures. The available evidence suggests that atypical antipsychotics and typical antipsychotics may be the drugs with the highest risk of falls and fractures, respectively. Quetiapine may be the medication with the highest risk of falls, and class Z drugs may be the medication with the highest risk of fractures.

The positive effects of preoperative chlorhexidine rinse to reduce postoperative pneumonia after kidney transplantation surgery

BACKGROUND

Postoperative pneumonia is one of the most observed hospital-acquired infections and increases the postoperative mortality rate. Further, it drives the healthcare systems under a severe financial burden. Preventing postoperative pneumonia is an incredibly challenging issue for clinicians. Since immunosuppression therapy, the patients who had kidney transplants are more vulnerable to postoperative infections. There is no data in the scientific literature focusing on the effects of preoperative oral care with chlorhexidine antiseptic solutions on postoperative pneumonia in kidney transplantation surgery cases. In the present research, we studied this topic.

METHODS

A prospective, randomized clinical trial was conducted at our institution between August 2020 and August 2022. Group A: Received 0.12 % chlorhexidine oral rinse preoperatively; Group B: Not received 0.12 % chlorhexidine oral rinse preoperatively. We analyzed the differences between the two trial groups using a chi-square or t-test. The Mann-Whitney U test was used for the categorical data.

RESULTS

Nine patients (17.6 %) were diagnosed with postoperative pneumonia in Group A and fourteen (25.9 %) in Group B (p < 0.05). Hospitalization time of Group B was prolonged (p < 0.05). In multivariate analysis, significant risk factors associated with postoperative pneumonia were advanced age, diabetes mellitus, smoking, delayed graft function and not gargling with 0.12 % chlorhexidine (p < 0.05).

CONCLUSIONS

To reduce postoperative pneumonia risk in patients undergoing kidney transplantation surgery, an oral health protocol including 0.12 % chlorhexidine mouth rinse seems beneficial.

Infectious complications following major heart surgery from the day of the surgery to hospital discharge

BACKGROUND

At some point in their lives, many people will require major heart surgery (MHS). Patients are generally older adults with various risk factors for infection. However, the incidence of infection after MHS is poorly known, as reported infection data are frequently biased due to different factors like the surgical procedure, postoperative timing, and infectious syndromes or etiologic agents, among others. In addition, most patient data are retrospectively obtained.

PURPOSE AND METHODS

Data were prospectively collected regarding the incidence of all nosocomial infections produced from the time of surgery to hospital discharge in a cohort of 800 adults consecutively undergoing a MHS procedure.

RESULTS

During postoperative hospitalization, 124 of the 800 participants developed one or more infections (15.5%): during their ICU stay in 68 patients (54.8%), during their stay on the general ward post ICU in 50 (40.3%), and during their stay in both wards in 6 (4.8%). The most common infections were pneumonia (related or not to mechanical ventilation), surgical site and bloodstream. As etiological agents, 193 pathogens were isolated: mostly Gram-negative bacilli (54.4%), followed by Gram-positive bacteria (30%), viruses (4.6%) and fungi (1.5%). In our cohort, all-cause mortality was recorded in 33 participants (4.1%) and 9 infection-related deaths (1.1%) were produced. Among subjects who developed infections, overall mortality was 13.7% and in those who did not, this was only 2.3%.

CONCLUSION

Infection following MHS remains frequent and severe. Our data suggest that hospital-acquired infection studies should consider episodes of infection in all populations during their entire hospital stay and not only those related to specific clinical syndromes or acquired while the patient is in intensive care.

Risk Factors and Short-Term Outcomes of Postoperative Pulmonary Complications in Elderly Patients After Cardiopulmonary Bypass

Objective

The risk factors of postoperative pulmonary complications (PPCs) have been extensively investigated in non-cardiac surgery and non-elderly adult patients undergoing cardiac surgery. However, data on elderly patients after cardiopulmonary bypass (CPB) is limited. This study aimed to evaluate the risk factors and short-term outcomes for PPCs in elderly patients undergoing CPB procedures.

Patients and Methods

Data from 660 patients who underwent CPB over a six-year period at a tertiary care hospital were collected. The primary outcome encompassed the incidence of PPCs, including re-intubation, postoperative mechanical ventilation exceeding 48 hours, pulmonary infection, pleural effusion requiring thoracic drainage, and acute respiratory distress syndrome. Missing data were managed using multiple imputation. Univariate analysis and the multiple logistic regression method were utilized to ascertain independent risk factors for PPCs.

Results

Among the 660 patients, PPCs were observed in 375 individuals (56.82%). Multiple logistic regression identified serum albumin levels <40 g/L, type of surgery, CPB duration >150 minutes, blood transfusion, and intra-aortic balloon pump use before extubation as independent risk factors for PPCs. Patients experiencing PPCs had prolonged mechanical ventilation, extended hospitalization and ICU stays, elevated postoperative mortality, and higher tracheotomy rates compared to those without PPCs.

Conclusion

Elderly patients following CPB displayed a substantially high incidence of PPCs, significantly impacting their prognosis. Additionally, this study identified five prominent risk factors associated with PPCs in this population. These findings enable clinicians to better recognize patients who may benefit from perioperative prevention strategies based on these risk factors.

Impact of Limited Enhanced Recovery Pathway for Cardiac Surgery: A Single-Institution Experience

OBJECTIVES

Enhanced recovery pathway (ERP) refers to extensive multidisciplinary, evidence-based pathways used to facilitate recovery after surgery. The authors assessed the impact that limited ERP protocols had on outcomes in patients undergoing cardiac surgery at their institution.

DESIGN

A retrospective cohort study.

SETTING

This study was a single-institution study conducted at a university hospital.

PARTICIPANTS

Patients undergoing open adult cardiac surgery.

INTERVENTIONS

Enhanced recovery pathways limited to preoperative, intraoperative, and postoperative management of pain, atrial fibrillation prevention, and nutrition optimization were implemented.

MEASUREMENTS AND MAIN RESULTS

A total of 1,058 patients were included in this study. There were 374 patients in each pre- and post-ERP cohort after propensity matching, with no significant baseline differences between the 2 cohorts. Compared to the matched patients in the pre-ERP group, patients in the post-ERP group had decreased total ventilation hours (6.8 v 7.8, p = 0.006), less use of postoperative opioid analgesics as determined by total morphine milligram equivalent (32.5 v 47.5, p < 0.001), and a decreased rate of postoperative atrial fibrillation (23.3% v 30.5%, p = 0.032). Post-ERP patients also experienced less subjective pain and postoperative nausea and drowsiness as compared to their matched pre-ERP cohorts.

CONCLUSIONS

Limited ERP implementation resulted in significantly improved perioperative outcomes. Patients additionally experienced less postoperative pain despite decreased opioid use. Implementation of ERP, even in a limited format, is a promising approach to improving outcomes in patients undergoing cardiac surgery.

The association of intraoperative and early postoperative events with risk of pneumonia following cardiac surgery

BACKGROUND

Pneumonia, the most common infection following cardiac surgery, is associated with major morbidity and mortality. Although prior work has identified preoperative risk factors for pneumonia, the present study evaluated the role and associated impact of intraoperative and postoperative risk factors on pneumonia after cardiac surgery.

METHODS

This observational cohort study evaluated 71,165 patients undergoing coronary and/or aortic valve surgery across 33 institutions between 2011 and 2021. Terciles of estimated pneumonia risk were compared between a validated preoperative model (Model One) and a model additionally accounting for significant intraoperative (eg, bypass duration) and postoperative (eg, extubation time) factors (Model Two). Logistic regression was used to develop and validate Model Two.

RESULTS

Postoperative pneumonia occurred in 2.62% of the patients. A total of 9 significant intraoperative and early postoperative risk factors were identified. The absolute risk of pneumonia increased across Model One terciles: low (≤1.04%), medium (1.04%-2.40%), and high (>2.40%). Model two performed well (c-statistic = 0.771). Most patients (60.1%) had no change in their preoperative versus intraoperative/postoperative risk tercile. The 19.6% of patients who increased their risk tercile with Model Two accounted for 18.6% of all pneumonia events.

CONCLUSIONS

This study identified 9 significant perioperative risk factors for pneumonia. Nearly 1 of every 5 patients moved into a higher pneumonia risk category based on their intraoperative and postoperative course. These findings may serve as the focus of future quality improvement efforts to reduce a patient's risk of postoperative pneumonia.

Multidrug-resistant bacterial infection in adult patients following cardiac surgery: clinical characteristics and risk factors

BACKGROUND

The prevalence of infections with multidrug-resistant organism (MDRO) pose great challenges for anti-infective therapy. Previous research on MDRO infections after cardiac surgery was limited. Therefore, understanding and mastering the clinical characteristics and risk predictors of MDRO infection after cardiac surgery is of great significance for standardized management of perioperative patients.

METHODS

The medical records of adult patients with MDRO infection after cardiac surgery from January 2018 to October 2021 were collected, and patients were divided into MDR infection group (n = 176) and non-MDR infection group (n = 233). Univariate and multivariate regression analysis of variables was performed to determine the risk predictors of MDRO infection.

RESULTS

The incidence of MDRO infection was 8.6%. Acinetobacter baumannii, Klebsiella pneumoniae and Pseudomonas aeruginosa were the most common, accounting for 37.3%, 23.5% and 18.0%, respectively. The main infection type were lower respiratory tract infection (LTRI = 29.0%). Univariate analysis showed that underwent coronary artery bypass graft (CABG) (P = 0.001) and secondary operation (P = 0.008), pre-infection exposure to vancomycin (P < 0.001) and linezolid (P = 0.002), combination antibiotics (P < 0.001), four antibiotics in combination (P = 0.005), glucocorticoid use (P = 0.029), preoperative hypoalbuminemia (P = 0.003) were risk factors for post-operative MDRO infection. Multivariate regression analysis showed that underwent CABG (OR = 1.228, 95%CI = 1.056∽1.427, P = 0.008), secondary operation (OR = 1.910, 95%CI = 1.131∽3.425, P = 0.015) and pre-infection exposure to linezolid (OR = 3.704, 95%CI = 1.291∽10.629, P = 0.005) were independent risk predictors for MDRO infection. The risk of MDRO infection increased with the length of stay in the ICU (P < 0.001) and the length of stay before diagnosis of infection (P = 0.003), and the difference was statistically significant. Meanwhile, the length of stay after infection (P = 0.005) and the total length of hospital stay (P < 0.001) were significantly longer in the MDRO infection group, and the all-cause mortality was numerically higher in the MDRO infection group (31.3% versus 23.2%).

CONCLUSIONS

The morbidity and mortality of MDRO infection was high in adult cardiac surgery, and many risk factors influence the occurrence of MDRO infection. In the future, clinicians should focus on high-risk patients, strengthen multidisciplinary collaboration on infection prevention and control measures, reduce the morbidity and mortality of MDRO infection, and improve the prognosis of in-hospital patients.

Results following implementation of a cardiac surgery ERAS protocol

INTRODUCTION

Adequate peri-operative care is essential to ensuring a satisfactory outcome in cardiac surgery. In this study, we look at the impact of evidence-based protocols implemented at Stanford Hospital.

METHODS

This study is a single-center, retrospective analysis. Enhanced recovery after surgery (ERAS) protocols were implemented for CABG/Valve and open Aortic operations on 11/1/2017 and 6/1/2018, respectively. Propensity-score matched analysis was used to compare 30-day mortality and morbidity of patients from the pre- and post-implementation cohorts. Secondary endpoints included the following: total hospital length of stay (LOS), ICU LOS, time until extubation, and time until urinary catheter removal.

RESULTS

After the implementation of the ERAS protocols for CABG/Valve operations, the median post-op LOS decreased from 7.0 days to 6.1 days (p<0.001), and median ICU LOS decreased from 69.9 hours to 54.0 (p = 0.098). There was no significant decrease in 30-day mortality (4% to 3.3%, p = 0.47). However, the incidence of post-op ventilator associated pneumonia (VAP) decreased from 5.0% to 2.1% (p = 0.003) and post-op urinary tract infections (UTIs) from 8.3% to 3.6% (p<0.001). Patients who underwent open aortic procedures experienced an improvement in 30-day mortality (7% to 3.5%, p = 0.012), decrease in median ICU LOS (91.7 hours to 69.6 hours, p<0.001), and a decrease in duration of mechanical ventilation (79.3 hours to 46.3 hours, p = 0.003). There was a decrease in post-op LOS, post-op VAP, and post-op UTI, although statistical significance was not attained.

CONCLUSION

At Stanford Hospital, ERAS pathways have led to decreased morbidity and LOS while simultaneously improving mortality amongst our critically ill patient population.

Development of the Modern Cardiothoracic Intensive Care Unit and Current Management

The modern cardiothoracic intensive care unit (CTICU) developed as a result of advances in critical care, cardiology, and cardiac surgery. Patients undergoing cardiac surgery today are sicker, frailer, and have more complex cardiac and noncardiac morbidities. CTICU providers need to understand postoperative implications of different surgical procedures, complications that can occur in CTICU patients, resuscitation protocols for cardiac arrest, and diagnostic and therapeutic interventions such as transesophageal echocardiography and mechanical circulatory support. Optimum CTICU care requires a multidisciplinary team with collaboration between cardiac surgeons and critical care physicians with training and experience in the care of CTICU patients.

Intraoperative use of cell saver devices decreases the rate of hyperlactatemia in patients undergoing cardiac surgery

Objective

This study was aimed to elucidate the effect of the intraoperative cell saver (CS) on hyperlactatemia of patients who underwent cardiac surgery.

Design

A sub-analysis of the CS was performed, which is a historial control trial of patients undergoing cardiac surgery.

Setting

This was a retrospective single-center and not blinded study.

Participants

We examined the occurrence of hyperlactatemia retrospectively in patients of CS group (n = 78) who were included in prospective trial and received valvular surgery, where CS was used during the procedure. Patients subjected to valvular surgery before February 2021 were adopted in control group (n = 79).

Interventions

Arterial blood was sampled (1) before cardiopulmonary bypass, (2) during bypass (3) immediately after bypass, (4) on ICU admission and (5) every 4 h up to 24 h postoperatively.

Measurements and main results

A lower incidence of hyperlactatemia (32.1% vs. 57.0%; P = 0.001) was observed in patients from the CS group. Furthermore, the blood lactate concentration was higher in control group than in CS group during CPB, post CPB, on ICU admission and lasted until 20 h after the operation. Multivariable analysis revealed that intraoperative use of CS was expected to be a protective factor against hyperlactatemia in this study (OR = 0.31, 95% CI 0.15-0.63, P = 0.001).

Conclusion

Intraoperative use of a CS device was associated with a lower incidence of hyperlactatemia. Whether such device use is valuable to limiting hyperlactatemia in cardiac patients after surgery requires further evaluation in larger prospective studies.

Evaluation of the Effects of an Extubation Protocol With Neostigmine on Duration of Mechanical Ventilation After Cardiac Surgery

OBJECTIVES

Residual neuromuscular blockade is associated with increased postoperative pulmonary complications. This study aimed to evaluate the effect of an extubation protocol incorporating neuromuscular blockade reversal (NMBR) by train-of-four monitoring on "fast-track" cardiac surgery outcomes.

DESIGN

A retrospective cohort study.

SETTING

At a university hospital.

PARTICIPANTS

Out of 1,843 cardiac surgery patients, from February 2, 2015, to March 31, 2017, 957 (52%) underwent cardiac surgery on or after February 29, 2016.

INTERVENTIONS

An extubation protocol, comprised of weaning from mechanical ventilation and NMBR guidelines, was implemented on February 29, 2016.

MEASUREMENTS AND MAIN RESULTS

The associations of baseline characteristics with the postoperative duration of mechanical ventilation (primary outcome) and respiratory and/or adverse complications (secondary outcomes) were evaluated using regression and interrupted- time series models. The implementation of an extubation protocol was associated with an 18% decrease in the duration of mechanical ventilation (incident rate ratio [IRR] 0.82, 95% CI 0.72-0.94; p < 0.01), statistically insignificant 26% increase in patients extubated ≤6 hours (odds ratio [OR] 1.26, 95% CI 0.97-1.65; p = 0.09), and 13% shorter intensive care unit length of stay (LOS) (IRR 0.87, 95% CI 0.79-0.97; p < 0.01). Patients undergoing isolated coronary artery bypass graft or isolated valve procedures, on or after February 29, 2016, had decreased extubation times (IRR 0.82, p < 0.01 and IRR 0.80, p = 0.02). The protocol did not have a statistically significant association with hospital LOS (IRR 0.98, p = 0.57) or readmission (OR 1.22, p = 0.33), and differences in the occurrence of pulmonary complications and adverse outcomes between the pre- and postprotocol groups were clinically insignificant.

CONCLUSIONS

The application of an extubation protocol incorporating NMBR based on neuromuscular monitoring was associated with a decrease in postoperative duration of mechanical ventilation and facilitated more patients meeting the early extubation benchmark without an increased risk of respiratory complications or adverse outcomes.

Machine learning-based prediction of 1-year mortality in hypertensive patients undergoing coronary revascularization surgery

BACKGROUND

Machine learning (ML) has shown promising results in all fields of medicine, including preventive cardiology. Hypertensive patients are at higher risk of mortality after coronary artery bypass graft (CABG) surgery; thus, we aimed to design and evaluate five ML models to predict 1-year mortality among hypertensive patients who underwent CABG.

HYOTHESIS

ML algorithms can significantly improve mortality prediction after CABG.

METHODS

Tehran Heart Center's CABG data registry was used to extract several baseline and peri-procedural characteristics and mortality data. The best features were chosen using random forest (RF) feature selection algorithm. Five ML models were developed to predict 1-year mortality: logistic regression (LR), RF, artificial neural network (ANN), extreme gradient boosting (XGB), and naïve Bayes (NB). The area under the curve (AUC), sensitivity, and specificity were used to evaluate the models.

RESULTS

Among the 8,493 hypertensive patients who underwent CABG (mean age of 68.27 ± 9.27 years), 303 died in the first year. Eleven features were selected as the best predictors, among which total ventilation hours and ejection fraction were the leading ones. LR showed the best prediction ability with an AUC of 0.82, while the least AUC was for the NB model (0.79). Among the subgroups, the highest AUC for LR model was for two age range groups (50-59 and 80-89 years), overweight, diabetic, and smoker subgroups of hypertensive patients.

CONCLUSIONS

All ML models had excellent performance in predicting 1-year mortality among CABG hypertension patients, while LR was the best regarding AUC. These models can help clinicians assess the risk of mortality in specific subgroups at higher risk (such as hypertensive ones).

Construction and Validation of a Predictive Model for the Risk of Ventilator-Associated Pneumonia in Elderly ICU Patients

Background

Ventilator-associated pneumonia (VAP) is among the most important hospital-acquired infections in an intensive-care unit setting. However, clinical practice lacks effective theoretical tools for preventing VAP in the elderly.

Aim

To describe the independent factors associated with VAP in elderly intensive-care unit (ICU) patients on mechanical ventilation (MV) and to construct a risk prediction model.

Methods

A total of 1851 elderly patients with MV in ICUs from January 2015 to September 2019 were selected from 12 tertiary hospitals. Study subjects were divided into a model group (n = 1219) and a validation group (n = 632). Two groups of patients were divided into a VAP group and a non-VAP group and compared. Univariate and logistic regression analyses were used to explore influencing factors for VAP in elderly ICU patients with MV, establish a risk prediction model, and draw a nomogram. We used the area under the receiver operating characteristic curve (AUROC) and the Hosmer-Lemeshow goodness-of-fit test to evaluate the predictive effect of the model. Findings regarding the length of ICU stay, surgery, C-reactive protein (CRP), and the number of reintubations were independent risk factors for VAP in elderly ICU patients with MV. Predictive-model verification results showed that the area under the curve (AUC) of VAP risk after MV in the modeling and verification groups was 0.859 and 0.813 (P < 0.001), respectively, while P values for the Hosmer-Lemeshow test in these two groups were 0.365 and 0.485, respectively.

Conclusion

The model could effectively predict the occurrence of VAP in elderly patients with MV in ICUs. This study is a retrospective study, so it has not been registered as a clinical study.

Pseudomonas aeruginosa: Infections, Animal Modeling, and Therapeutics

Pseudomonas aeruginosa is an important Gram-negative opportunistic pathogen which causes many severe acute and chronic infections with high morbidity, and mortality rates as high as 40%. What makes P. aeruginosa a particularly challenging pathogen is its high intrinsic and acquired resistance to many of the available antibiotics. In this review, we review the important acute and chronic infections caused by this pathogen. We next discuss various animal models which have been developed to evaluate P. aeruginosa pathogenesis and assess therapeutics against this pathogen. Next, we review current treatments (antibiotics and vaccines) and provide an overview of their efficacies and their limitations. Finally, we highlight exciting literature on novel antibiotic-free strategies to control P. aeruginosa infections.

Sex Disparities in Failure to Rescue After Cardiac Surgery in California and New York

BACKGROUND

Women have a higher risk of mortality than men after cardiac surgery independent of other risk factors. The reason for this may not be limited to patient-specific variables. Failure to rescue (FTR) patients from death after a postoperative complication is a nationally endorsed quality care metric. We aimed to identify whether sex disparities exist in the quality of care after cardiac surgery using FTR rates.

METHODS

A retrospective analysis of 30 973 men (70.4%) and 13 033 women (29.6%) aged over 18 years undergoing coronary artery bypass graft or valve surgery in New York (2016-2019) and California (2016-2018) who experienced at least one serious postoperative complication. The primary outcome was the FTR. Multivariable logistic regression was used to identify predictors of death after complication. Propensity matching was used to adjust for baseline differences between sexes and yielded 12 657 pairs.

RESULTS

Female patients that experienced complications were older (mean age 67.8 versus 66.7, P<0.001), more frail (median frailty score 0.1 versus 0.07, P<0.001), and had more comorbidities (median Charlson score 2.5 versus 2.3, P<0.001) than male patients. The overall FTR rate was 5.7% (2524), men were less likely to die after a complication than women (4.8% versus 8%, P<0.001). Independent predictors of FTR included female sex (relative risk [RR]: 1.46 [CI, 1.30-1.62]), area-level poverty rate >20% (RR, 1.21 [CI, 1.01-1.59]), higher frailty (RR, 2.83 [CI, 1.35-5.93]), undergoing concomitant coronary artery bypass graft and valve surgeries (RR, 1.69 [CI, 1.49-1.9]), and higher number of postoperative complications (RR, 16.28 [CI, 14-18.89]). In the propensity-matched cohorts, the FTR rate remained significantly lower among men than women (6.0% versus 8.0%, P<0.001).

CONCLUSIONS

Women are less likely to be rescued from death following postoperative complications, independent of socioeconomic and clinical characteristics. Further research is warranted to investigate the clinical practices contributing to this disparity in quality of care following cardiac surgery.

Effect of Ventilation Strategy During Cardiopulmonary Bypass on Arterial Oxygenation and Postoperative Pulmonary Complications After Pediatric Cardiac Surgery: A Randomized Controlled Study

OBJECTIVES

To compare the effects of 3 ventilation strategies during cardiopulmonary bypass (CPB) on arterial oxygenation and postoperative pulmonary complications (PPCs).

DESIGN

A prospective, randomized, controlled study.

SETTING

A single-center tertiary teaching hospital.

PARTICIPANTS

One hundred twenty pediatric patients undergoing elective repair of congenital acyanotic heart diseases with CPB.

INTERVENTIONS

Patients were assigned randomly into 3 groups according to ventilation strategy during CPB as follows: (1) no mechanical ventilation (NOV), (2) continuous positive airway pressure (CPAP) of 5 cmH₂O, (3) low tidal volume (LTV), pressure controlled ventilation (PCV), respiratory rate (RR) 20-to-30/min, and peak inspiratory pressure adjusted to keep tidal volume (Vt) 2 mL/kg.

MEASUREMENTS AND MAIN RESULTS

The PaO₂/fraction of inspired oxygen (F_IO₂) ratio and PaO₂ were higher in the 5 minutes postbypass period in the LTV group but were nonsignificant. The PaO₂/F_IO₂ ratio and PaO₂ were significant after chest closure and 1 hour after arrival to the intensive care unit with a higher PaO₂/F_IO₂ ratio and PaO₂ in the LTV group. Regarding the oxygenation index, the LTV group was superior to the NOV group at the 3 time points, with lower values in the LTV group. There were no significant differences in the predictive indices among the 3 groups, including the extubation time, and postoperative intensive care unit stays days. The incidence of PPCs did not significantly differ among the 3 groups.

CONCLUSIONS

Maintaining ventilation during CPB was associated with better oxygenation and did not reduce the incidence of PPCs in pediatric patients undergoing cardiac surgery.

The Spillover Effects of Quality Improvement Beyond Target Populations in Mechanical Ventilation

To assess the impact of a mechanical ventilation quality improvement program on patients who were excluded from the intervention.

DESIGN

Before-during-and-after implementation interrupted time series analysis to assess the effect of the intervention between coronary artery bypass grafting (CABG) surgery patients (included) and left-sided valve surgery patients (excluded).

SETTING

Academic medical center.

PATIENTS

Patients undergoing CABG and left-sided valve procedures were analyzed.

INTERVENTIONS

A postoperative mechanical ventilation quality improvement program was developed for patients undergoing CABG.

MEASUREMENTS AND MAIN RESULTS

Patients undergoing CABG had a median mechanical ventilation time of 11 hours during P0 ("before" phase) and 6.22 hours during P2 ("after" phase; p < 0.001). A spillover effect was observed because mechanical ventilation times also decreased from 10 hours during P0 to 6 hours during P2 among valve patients who were excluded from the protocol (p < 0.001). The interrupted time series analysis demonstrated a significant level of change for ventilation time from P0 to P2 for both CABG (p < 0.0001) and valve patients (p < 0.0001). There was no significant difference in the slope of change between the CABG and valve patient populations across time cohorts (P0 vs P1 [p = 0.8809]; P1 vs P2 [p = 0.3834]; P0 vs P2 [p = 0.7672]), which suggests that the rate of change in mechanical ventilation times was similar between included and excluded patients.

CONCLUSIONS

Decreased mechanical ventilation times for patients who were not included in a protocol suggests a spillover effect of quality improvement and demonstrates that quality improvement can have benefits beyond a target population.

Risk factors for ventilator-associated pneumonia due to multi-drug resistant organisms after cardiac surgery in adults

Background

Ventilator-associated pneumonia (VAP) is one of the most common intensive care unit (ICU)-acquired infections, which can cause multiple adverse events. Due to bacterial mutation and overuse of antimicrobial drugs, multidrug-resistant organisms (MDRO) has become one of the major causes of postoperative VAP infections in cardiac patients. Therefore, this study aims to explore the risk factors for VAP with MDRO following cardiac surgery in adults.

Methods

The clinical data of adult VAP patients following cardiac surgery in the hospital from Jan 2017 to May 2021 were analyzed retrospectively, and the patients were divided into the MDRO VAP group and the non-MDRO VAP group. Univariable and multivariable logistic regression analyses were performed on risk factors in patients with MDRO VAP. The species and drug sensitivity of pathogens isolated from the VAP patients were also analyzed.

Results

A total of 61 VAP cases were involved in this study, with 34 cases in the MDRO VAP group (55.7%) and 27 cases in the non-MDRO VAP group (44.3%). Multivariable logistic regression analysis showed that independent risk factors for MDRO VAP included preoperative creatinine clearance rate (CCR) ≥ 86.6ml, intraoperative cardiopulmonary bypass (CPB) time ≥ 151 min, postoperative acute kidney injury (AKI) and nasal feeding. Gram-negative bacilli were the main pathogens in VAP patients (n = 54, 90.0%), with the highest rate of Acinetobacter baumannii (n = 24, 40.0%). Additionally, patients with MDRO VAP had a significantly longer postoperative intensive care unit (ICU) duration and higher hospitalization costs than non-MDRO VAP patients, but there was no notable difference in the 28-day mortality rate between the two groups.

Conclusion

Based on implementing measures to prevent VAP, clinicians should pay more attention to patients with kidney disease, longer intraoperative CPB time, and postoperative nasal feeding to avoid MDRO infections.

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.

A 3-hour fast-track extubation protocol for early extubation after cardiac surgery

Objectives

Early extubation after cardiac surgery improves outcomes and reduces cost. We investigated the effect of a multidisciplinary 3-hour fast-track protocol on extubation, intensive care unit length of stay time, and reintubation rate after a wide range of cardiac surgical procedures.

Methods

We performed an observational study of 472 adult patients undergoing cardiac surgery at a large academic institution. A multidisciplinary 3-hour fast-track protocol was applied to a wide range of cardiac procedures. Data were collected 4 months before and 6 months after protocol implementation. Cox regression model assessed factors associated with extubation time and intensive care unit length of stay.

Results

A total of 217 patients preprotocol implementation and 255 patients postprotocol implementation were included. Baseline characteristics were similar except for the median procedure time and dexmedetomidine use. The median extubation time was reduced by 44% (4:43 hours vs 3:08 hours; P < .001) in the postprotocol group. Extubation within 3 hours was achieved in 49.4% of patients in the postprotocol group compared with 25.8% patients in the preprotocol group; P < .001. There was no statistically significant difference in the intensive care unit length of stay after controlling for other factors. Early extubation was associated with only 1 patient requiring reintubation in the postprotocol group.

Conclusions

The multidisciplinary 3-hour fast-track extubation protocol is a safe and effective tool to further reduce the duration of mechanical ventilation after a wide range of cardiac surgical procedures. The protocol implementation did not decrease the intensive care unit length of stay.

Evaluation of the significance of interleukin-6 in the diagnosis of postoperative pneumonia: a prospective study

Background

Postoperative pneumonia (PP) is one of the most common complications after cardiac surgery. This study was designed to access the diagnostic value of interleukin-6 (IL-6) for pneumonia within the first 5 days after cardiac surgery in adults.

Method

This prospective observational study enrolled 694 patients who admitted to our center from 10 October 2020 to 30 June 2021. Blood samples were collected after admission and on five consecutive days after surgery to measure IL-6, procalcitonin (PCT), C-reactive protein (CRP) and white blood cells (WBC) respectively. Combined with clinical data, we assessed the diagnostic performance of different biomarkers using univariate and multifactorial analyses as well as receiver operating characteristic curves (ROC) and the area under the curve (AUC).

Result

Finally, 68 patients were diagnosed with PP (PP Group). In addition, 626 cases were assigned to the control group (Non-PP Group). From postoperative day 1 (POD1) to day 5, IL-6 and PCT levels showed higher diagnostic value (P < 0.001, P < 0.05, respectively); meanwhile, there was no difference in white blood cell counts between the two groups; CRP showed some value from POD2 onwards (P < 0.001). Among these biomarkers, IL-6 on POD1 [AUC: 0.78, 95% confidence interval (CI): 0.71–0.83], IL-6 on POD2 (AUC: 0.77, 95% CI: 0.71–0.82) and CRP levels on POD3 (AUC: 0.77, 95% CI: 0.70–0.84) had the highest diagnostic value. Multivariate analysis found that smoking status [odds ratio(OR): 7.79, 95% CI: 3.05, 19.88, p < 0.001], drinking status (OR: 22.68, 95% CI: 9.29, 55.37, p < 0.001) and hypertension (OR: 2.85, 95% CI: 1.28, 6.35, p = 0.011), IL-6 on POD2 (OR: 1.01, 95% CI: 1.00, 1.01, p = 0.018), mechanical ventilation time (OR: 1.03, 95% CI: 1.00, 1.05, p = 0.040) and intensive care unit stay time (OR: 1.01, 95% CI: 1.00, 1.02, p < 0.001) were independent risk factors for postoperative pneumonia.

Conclusion

Smoking, drinking, hypertension, prolonged duration of mechanical ventilation and intensive care unit stay, and IL-6 on POD2 were independent risk factors for pneumonia after cardiovascular surgery. IL-6 level on POD2 may serve as a promising indicator, better than WBC, PCT and CRP.

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.

Usefulness of lung ultrasound for early detection of hospital-acquired pneumonia in cardiac critically ill patients on venoarterial extracorporeal membrane oxygenation

Background

Hospital-acquired pneumonia (HAP) is the most common and severe complication in patients treated with venoarterial extracorporeal membrane oxygenation (VA ECMO) and its diagnosis remains challenging. Nothing is known about the usefulness of lung ultrasound (LUS) in early detection of HAP in patients treated with VA ECMO. Also, LUS and chest radiography were performed when HAP was suspected in cardiac critically ill adult VA ECMO presenting with acute respiratory failure. The sonographic features of HAP in VA ECMO patients were determined and we assessed the performance of the lung ultrasound simplified clinical pulmonary score (LUS-sCPIS), the sCPIS and bioclinical parameters or chest radiography alone for early diagnosis of HAP.

Results

We included 70 patients, of which 44 (63%) were independently diagnosed with HAP. LUS examination revealed that color Doppler intrapulmonary flow (P = 0.0000043) and dynamic air bronchogram (P = 0.00024) were the most frequent HAP-related signs. The LUS-sCPIS (area under the curve = 0.77) yielded significantly better results than the sCPIS (area under the curve = 0.65; P = 0.004), while leukocyte count, temperature and chest radiography were not discriminating for HAP diagnosis.

Discussion

Diagnosis of HAP is a daily challenge for the clinician managing patients on venoarterial ECMO. Lung ultrasound can be a valuable tool as the initial imaging modality for the diagnosis of pneumonia. Color Doppler intrapulmonary flow and dynamic air bronchogram appear to be particularly insightful for the diagnosis of HAP.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-022-01013-9.

Development and validation of a nomogram model for pneumonia after redo cardiac surgery

AIMS

Postoperative pneumonia (POP) after redo cardiac surgery is prevalent, associated with poor outcome. The aim of this study was to identify independent risk factors for POP after redo cardiac surgery and to develop and validate a prediction model.

METHODS

Adults undergoing redo cardiac surgery from 2016 to 2019 were identified in a single-institution database. Using a 2: 1 ratio, the patients were randomly divided into training and validation sets. Univariate and multivariate analyses were applied to identify independent predictors for POP in the training set. A nomogram model was constructed for clinical utility and was validated in the validation set.

RESULTS

POP developed in 72 of the 376 patients (19.1%). Four independent risk factors were identified, including age, chronic obstructive pulmonary disease, serum creatinine level and intraoperative blood transfusion volume. A nomogram based on the four predictors was constructed, with good discrimination in both the training (c-index: 0.86) and validation sets (c-index: 0.78). The model was well calibrated, with a Hosmer-Lemeshow χ 2 -value of 7.31 ( P   =  0.50) in the training set and 7.41 ( P   =  0.49) in the validation set. The calibration was also good by visual inspection. The decision and clinical impact curves of the nomogram indicated good clinical utility. Three risk intervals were identified based on the nomogram for better risk stratification.

CONCLUSION

We developed and validated a nomogram model for POP after redo cardiac surgery. The model may have good clinical utility in risk evaluation and individualized treatment to reduce adverse events. Graphical abstract Incidence, risk factor, and outcomes of postoperative pneumonia after redo cardiac surgery: http://links.lww.com/JCM/A445 .

Combining Minimally Invasive Surgery With Ultra-Fast-Track Anesthesia in HeartMate 3 Patients: A Pilot Study

BACKGROUND

Minimally invasive surgery for left ventricular assist device implantation may have advantages over conventional sternotomy (CS). Additionally, ultra-fast-track anesthesia has been linked to better outcomes after cardiac surgery. This study summarizes our early experience of combining minimally invasive surgery with ultra-fast-track anesthesia (MIFTA) in patients receiving HeartMate 3 devices and compares the outcomes between MIFTA and CS.

METHODS

From October 2015 to January 2019, 18 of 49 patients with Interagency Registry for Mechanically Assisted Circulatory Support profiles >1 underwent MIFTA for HeartMate 3 implantation. For bias reduction, propensity scores were calculated and used as a covariate in a regression model to analyze outcomes. Weighted parametric survival analysis was performed.

RESULTS

In the MIFTA group, intensive care unit stays were shorter (mean difference, 8 days [95% CI, 4-13]; P<0.001), and the incidences of pneumonia and right heart failure were lower than those in the CS group (odds ratio, 1.36 [95% CI, 1.01-1.75]; P=0.016, respectively). At 6 and 12 hours postoperatively, MIFTA patients had a better hemodynamic performance with lower pulmonary wedge pressure (mean difference, 2.23 mm Hg [95% CI, 0.41-4.06]; P=0.028) and a higher right ventricular stroke work index (mean difference, -1.49 g·m/m² per beat [95% CI, -2.95 to -0.02]; P=0.031). CS patients had a worse right heart failure-free survival rate (hazard ratio, 2.35 [95% CI, 0.96-5.72]; P<0.01).

CONCLUSIONS

Compared with CS, MIFTA is a beneficial approach for non-Interagency Registry for Mechanically Assisted Circulatory Support 1 HeartMate 3 patients with lower adverse event incidences, better hemodynamic performance, and preserved right heart function. Future large multicentric investigations are required to verify MIFTA's effects on outcomes.

Development and validation of a risk prediction model for postoperative pneumonia in adult patients undergoing Stanford type A acute aortic dissection surgery: a case control study

Background

Pneumonia is a common complication after Stanford type A acute aortic dissection surgery (AADS) and contributes significantly to morbidity, mortality, and length of stay. The purpose of this study was to identify independent risk factors associated with pneumonia after AADS and to develop and validate a risk prediction model.

Methods

Adults undergoing AADS between 2016 and 2019 were identified in a single-institution database. Patients were randomly divided into training and validation sets at a ratio of 2:1. Preoperative and intraoperative variables were included for analysis. A multivariate logistic regression model was constructed using significant variables from univariate analysis in the training set. A nomogram was constructed for clinical utility and the model was validated in an independent dataset.

Results

Postoperative pneumonia developed in 170 of 492 patients (34.6%). In the training set, multivariate analysis identified seven independent predictors for pneumonia after AADS including age, smoking history, chronic obstructive pulmonary disease, renal insufficiency, leucocytosis, low platelet count, and intraoperative transfusion of red blood cells. The model demonstrated good calibration (Hosmer–Lemeshow χ² = 3.31, P = 0.91) and discrimination (C-index = 0.77) in the training set. The model was also well calibrated (Hosmer–Lemeshow χ² = 5.73, P = 0.68) and showed reliable discriminatory ability (C-index = 0.78) in the validation set. By visual inspection, the calibrations were good in both the training and validation sets.

Conclusion

We developed and validated a risk prediction model for pneumonia after AADS. The model may have clinical utility in individualized risk evaluation and perioperative management.

Pseudomonas aeruginosa Pneumonia: Evolution of Antimicrobial Resistance and Implications for Therapy

Pseudomonas aeruginosa (PA), a non-lactose-fermenting gram-negative bacillus, is a common cause of nosocomial infections in critically ill or debilitated patients, particularly ventilator-associated pneumonia (VAP), and infections of urinary tract, intra-abdominal, wounds, skin/soft tissue, and bloodstream. PA rarely affects healthy individuals, but may cause serious infections in patients with chronic structural lung disease, comorbidities, advanced age, impaired immune defenses, or with medical devices (e.g., urinary or intravascular catheters, foreign bodies). Treatment of pseudomonal infections is difficult, as PA is intrinsically resistant to multiple antimicrobials, and may acquire new resistance determinants even while on antimicrobial therapy. Mortality associated with pseudomonal VAP or bacteremias is high (> 35%) and optimal therapy is controversial. Over the past three decades, antimicrobial resistance (AMR) among PA has escalated globally, via dissemination of several international multidrug resistant "epidemic" clones. We discuss the importance of PA as a cause of pneumonia including health care-associated pneumonia, hospital-acquired pneumonia, VAP, the emergence of AMR to this pathogen, and approaches to therapy (both empirical and definitive).

Diaphragm Ultrasound in Cardiac Surgery: State of the Art

In cardiac surgery, patients are at risk of phrenic nerve injury, which leads to diaphragm dysfunction and acute respiratory failure. Diaphragm dysfunction (DD) is relatively frequent in cardiac surgery and particularly affects patients after coronary artery bypass graft. The onset of DD affects patients’ prognosis in term of weaning from mechanical ventilation and hospital length of stay. The authors present a narrative review about diaphragm physiology, techniques used to assess diaphragm function, and the clinical application of diaphragm ultrasound in patients undergoing cardiac surgery.

Effect of breast milk oral care in infants who underwent surgical correction of ventricular septal defect

OBJECTIVE

This study explored the clinical effect of employing breast milk oral care for infants who underwent surgical correction of ventricular septal defect.

METHODS

A prospective randomised controlled study was conducted in a provincial hospital between January, 2020 and July, 2020 in China. Patients were randomly divided into an intervention group (breast milk oral care, n = 28) and a control group (physiological saline oral care, n = 28). The intervention group was given oral nursing using breast milk for infants in the early post-operative period, and the control group was given oral nursing using physiological saline. Related clinical data were recorded and analysed.

RESULTS

There were no significant differences in age, gender, weight, operation time, cardiopulmonary bypass time, or aortic cross-clamping time between the two groups. Compared with the physiological saline oral care group, the mechanical ventilation duration, the length of ICU stay in the breast milk oral care group were significantly shorter. The time of start feeding and total enteral nutrition were significantly earlier in the intervention group than those in the control group. The incidence of post-operative pneumonia in the breast milk oral care group was 3.6%, which was significantly lower than that of the physiological saline oral care group.

CONCLUSION

The use of breast milk for oral care in infants who underwent surgical correction of VSD can reduce the incidence of post-operative pneumonia and promote the recovery of gastrointestinal function.

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.

Ultrasound-Guided Pleural Effusion Drainage: Effect on Oxygenation, Respiratory Mechanics, and Liberation from Mechanical Ventilation in Surgical Intensive Care Unit Patients

The question as to whether an aggressive management of post-operative pleural effusion may improve clinical outcomes after major surgery remains unanswered. The aim of this study was to investigate the effect of ultrasound-guided pleural effusion drainage on oxygenation, respiratory mechanics, and liberation from mechanical ventilation in surgical intensive care unit patients. Oxygenation and respiratory mechanics were measured before and after drainage. Over an 18-month period, a total of 62 patients were analyzed. The mean drainage volume during the first 24 h was 864 ± 493 mL, and there were no procedural complications. Both the mean PaO₂/FiO₂ ratio and lung compliance improved after drainage. Additionally, 41.9% (n = 26) of patients were ventilator-free within 72 h after drainage. Multivariable logistic regression analysis revealed that non-cardiovascular or thoracic surgery (odds ratio [OR] = 4.968, p = 0.046), a longer time interval from operation to the onset of pleural effusion (OR = 1.165, p = 0.005), and a higher peak airway pressure (OR = 1.303, p = 0.009) were independent adverse predictors for being free from mechanical ventilation within 72 h after drainage. Specifically, patients with a time from surgery to the onset of pleural effusion ≤6 days-but not those with an interval >6 days-showed a significant post-procedural improvement in terms of PaO₂/FiO₂ ratio, PaCO₂, peak airway pressure, and dynamic lung compliance. In summary, ultrasound-guided pleural effusion drainage resulted in significant clinical benefits in mechanically ventilated ICU patients after major surgery-especially in those with early-onset effusion who received thoracic surgery.

Plasma and Lung Tissue Pharmacokinetics of Ceftaroline Fosamil in Patients Undergoing Cardiac Surgery with Cardiopulmonary Bypass: an In Vivo Microdialysis Study

Ceftaroline fosamil, a fifth-generation cephalosporin antibiotic with activity against methicillin-resistant Staphylococcus aureus (MRSA), is currently approved for the treatment of pneumonia and complicated skin and soft tissue infections. However, pharmacokinetics data on free lung tissue concentrations in critical patient populations are lacking. The aim of this study was to evaluate the pharmacokinetics of the high-dose regimen of ceftaroline in plasma and lung tissue in cardiac surgery patients during intermittent and continuous administration. Nine patients undergoing elective cardiac surgery on cardiopulmonary bypass were included in this study and randomly assigned to intermittent or continuous administration. Eighteen hundred milligrams of ceftaroline fosamil was administered intravenously as either 600 mg over 2 h every 8 h (q8h) (intermittent group) or 600 mg over 2 h (loading dose) plus 1,200 mg over 22 h (continuous group). Interstitial lung tissue concentrations were measured by in vivo microdialysis. Relevant pharmacokinetics parameters were calculated for each group. Plasma exposure levels during intermittent and continuous administration were comparable to those of previously published studies and did not differ significantly between the two groups. In vivo microdialysis demonstrated reliable and adequate penetration of ceftaroline into lung tissue during intermittent and continuous administration. The steady-state area under the concentration-time curve from 0 to 8 h (AUCss 0-8) and the ratio of AUCSS 0-8 in lung tissue and AUC in plasma (AUClung/plasma) were descriptively higher in the continuous group. Continuous administration of ceftaroline fosamil achieved a significantly higher proportion of time for which the free drug concentration remained above 4 times the minimal inhibitory concentration (MIC) during the dosing interval (% fT>4xMIC) than intermittent administration for pathogens with a MIC of 1 mg/liter. Ceftaroline showed adequate penetration into interstitial lung tissue of critically ill patients undergoing major cardiothoracic surgery, supporting its use for pneumonia caused by susceptible pathogens.

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

Comparative Evaluation on Impacts of Fibronectin, Heparin-Chitosan, and Albumin Coating of Bacterial Nanocellulose Small-Diameter Vascular Grafts on Endothelialization In Vitro

In this study, we contrast the impacts of surface coating bacterial nanocellulose small-diameter vascular grafts (BNC-SDVGs) with human albumin, fibronectin, or heparin–chitosan upon endothelialization with human saphenous vein endothelial cells (VEC) or endothelial progenitor cells (EPC) in vitro. In one scenario, coated grafts were cut into 2D circular patches for static colonization of a defined inner surface area; in another scenario, they were mounted on a customized bioreactor and subsequently perfused for cell seeding. We evaluated the colonization by emerging metabolic activity and the preservation of endothelial functionality by water soluble tetrazolium salts (WST-1), acetylated low-density lipoprotein (AcLDL) uptake assays, and immune fluorescence staining. Uncoated BNC scaffolds served as controls. The fibronectin coating significantly promoted adhesion and growth of VECs and EPCs, while albumin only promoted adhesion of VECs, but here, the cells were functionally impaired as indicated by missing AcLDL uptake. The heparin–chitosan coating led to significantly improved adhesion of EPCs, but not VECs. In summary, both fibronectin and heparin–chitosan coatings could beneficially impact the endothelialization of BNC-SDVGs and might therefore represent promising approaches to help improve the longevity and reduce the thrombogenicity of BNC-SDVGs in the future.

High Flow Oxygen Therapy at Two Initial Flow Settings versus Conventional Oxygen Therapy in Cardiac Surgery Patients with Postextubation Hypoxemia: A Single-Center, Unblinded, Randomized, Controlled Trial

In cardiac surgery patients with pre-extubation PaO₂/inspired oxygen fraction (FiO₂) < 200 mmHg, the possible benefits and optimal level of high-flow nasal cannula (HFNC) support are still unclear; therefore, we compared HFNC support with an initial gas flow of 60 or 40 L/min and conventional oxygen therapy. Ninety nine patients were randomly allocated (respective ratio: 1:1:1) to I = intervention group 1 (HFNC initial flow = 60 L/min, FiO₂ = 0.6), intervention group 2 (HFNC initial flow = 40 L/min, FiO₂ = 0.6), or control group (Venturi mask, FiO₂ = 0.6). The primary outcome was occurrence of treatment failure. The baseline characteristics were similar. The hazard for treatment failure was lower in intervention group 1 vs. control (hazard ratio (HR): 0.11, 95% CI: 0.03–0.34) and intervention group 2 vs. control (HR: 0.30, 95% CI: 0.12–0.77). During follow-up, the probability of peripheral oxygen saturation (SpO₂) > 92% and respiratory rate within 12–20 breaths/min was 2.4–3.9 times higher in intervention group 1 vs. the other 2 groups. There was no difference in PaO₂/FiO₂, patient comfort, intensive care unit or hospital stay, or clinical course complications or adverse events. In hypoxemic cardiac surgery patients, postextubation HFNC with an initial gas flow of 60 or 40 L/min resulted in less frequent treatment failure vs. conventional therapy. The results in terms of SpO₂/respiratory rate targets favored an initial HFNC flow of 60 L/min.

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

Background

Postoperative pneumonia is the main infectious complication following cardiac surgery and is associated with significant increases in morbidity, mortality and health care costs. The aim of this study was to identify potential risk factors related to the occurrence of postoperative pneumonia in adult patients undergoing cardiac surgery and to develop a predictive system.

Methods

Adult patients who underwent open heart surgery in our institution between 2016 and 2019 were enrolled in this study. Preoperative and intraoperative variables were collected and analyzed. A multivariate prediction model for evaluating the risk of postoperative pneumonia was established using logistic regression analysis via forward stepwise selection, and points were assigned to significant risk factors based on their regression coefficient values.

Results

Postoperative pneumonia occurred in 530 of the 5,323 patients (9.96%). Prolonged stays in the postoperative intensive care unit (ICU) and hospital, as well as higher mortality (25.66% versus 0.65%), were observed in patients with postoperative pneumonia. Multivariate analysis identified 13 independent risk factors including patient demographics, comorbidities, cardiac function, cardiopulmonary bypass (CPB) duration, and blood transfusion. The prediction model showed good discrimination (C-statistic: 0.80) and was well calibrated (Hosmer-Lemeshow χ²=7.907, P value =0.443). A 32-point risk score was generated, and then three risk intervals were defined.

Conclusions

We derived and validated a prediction model for postoperative pneumonia after cardiac surgery incorporating 13 easily discernible risk factors. The scoring system may be helpful for individualized risk estimations and clinical decision-making.

Diaphragm Dysfunction After Cardiac Surgery: Reappraisal

OBJECTIVES

The aim of this study was to re-investigate the incidence, risk factors, and outcomes of postoperative diaphragmatic dysfunction (DD) with actual cardiac surgery procedures.

DESIGN

Single-center, retrospective, observational study based on a prospectively collected database.

SETTING

Tertiary care cardiac surgery center.

PARTICIPANTS

Patients who underwent cardiac surgery between January 2016 and September 2019.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The DD group included patients with clinically perceptible diaphragmatic paralysis, which was confirmed by chest ultrasound (amplitude of the diaphragm movement in time-motion mode at rest, after a sniff test). The primary endpoint was the incidence of DD. Among 3,577 patients included, the authors found 272 cases of DD (7.6%). Individuals with DD had more arterial hypertension (64.3% v 52.6%; p < 0.0001), higher body mass index (BMI) (28 [25-30] kg/m²v 26 [24-29] kg/m²; p < 0.0002), and higher incidence of coronary bypass grafting (CABG) (58.8% v 46.6%; p = 0.0001). DD was associated with more postoperative pneumonia (23.9% v 8.7%; p < 0.0001), reintubation (8.8% v 2.9%; p < 0.0001), tracheotomy (3.3% v 0.3%; p < 0.0001), noninvasive ventilation (45.6% v 5.4%; p < 0.0001), duration of mechanical ventilation (five [four-11] hours v four [three-six] hours; p < 0.0001), and intensive care unit and hospital stays (14 [11-17] days v 13 [11-16] days; p < 0.0001). In multivariate analysis, DD was associated with CABG (odds ratio [OR] 1.9 [1.5-2.6]; p = 0.0001), arterial hypertension (OR 1.4 [1.1-1.9]; p = 0.008), and BMI (OR per point 1.04 [1.01-1.07] kg/m²; p = 0.003).

CONCLUSIONS

The incidence of symptomatic DD after cardiac surgery was 7.6%, leading to respiratory complications and increased ICU stay. CABG was the principal factor associated with DD.

Machine learning prediction models for prognosis of critically ill patients after open-heart surgery

We aimed to build up multiple machine learning models to predict 30-days mortality, and 3 complications including septic shock, thrombocytopenia, and liver dysfunction after open-heart surgery. Patients who underwent coronary artery bypass surgery, aortic valve replacement, or other heart-related surgeries between 2001 and 2012 were extracted from MIMIC-III databases. Extreme gradient boosting, random forest, artificial neural network, and logistic regression were employed to build models by utilizing fivefold cross-validation and grid search. Receiver operating characteristic curve, area under curve (AUC), decision curve analysis, test accuracy, F1 score, precision, and recall were applied to access the performance. Among 6844 patients enrolled in this study, 215 patients (3.1%) died within 30 days after surgery, part of patients appeared liver dysfunction (248; 3.6%), septic shock (32; 0.5%), and thrombocytopenia (202; 2.9%). XGBoost, selected to be our final model, achieved the best performance with highest AUC and F1 score. AUC and F1 score of XGBoost for 4 outcomes: 0.88 and 0.58 for 30-days mortality, 0.98 and 0.70 for septic shock, 0.88 and 0.55 for thrombocytopenia, 0.89 and 0.40 for liver dysfunction. We developed a promising model, presented as software, to realize monitoring for patients in ICU and to improve prognosis.

Pulmonary Complications of Cardiac Surgery

Cardiothoracic surgery posits an arrangement of large, significant hemodynamic, and physiologic alterations upon the human body, which predisposes a patient to develop pathology. The care of these patients in the postoperative realm requires an astute physician with deep understanding of the cardiopulmonary system, who is able to address subtle developing problems promptly, before the patient suffers further sequelae. In this review, we describe the presentation and management of an assortment of important complications which occur in the pulmonary system. In addition, we aim to shed better light upon how the physiology of a patient responds to the condition of cardiothoracic surgery.

Impact of nosocomial infections on patient mortality following cardiac surgery

STUDY OBJECTIVE

To determine the rate of nosocomial infection among patients undergoing cardiac surgery and to identify risk factors and the impact of these infections on patient mortality.

DESIGN

Prospective observational study.

SETTING

Intensive Care Unit (ICU).

PATIENTS

1097 adult patients who underwent cardiac surgery at Hospital Clínico Universitario de Valladolid between January 2011 and January 2016.

INTERVENTIONS

None.

MEASUREMENTS

Preoperative, intraoperative and postoperative medical, surgical and anaesthetic variables.

MAIN RESULTS

A total of 111 patients (10.1%) acquired a nosocomial infection in the postoperative period. Pneumonia was the most frequent (4.2%) nosocomial infection. Three independent risk factors for the development of a nosocomial infection were identified: cardiopulmonary bypass time, kidney failure and emergency surgery. The stay in the ICU was significantly higher in patients who developed a nosocomial infection (16.6 ± 38.8 vs. 4.4 ± 17.8, P < 0.001). The mortality rate of patients who acquired a nosocomial infection was significantly greater (18%) than that of patients who did not acquire a nosocomial infection (5%) (P < 0.001). The 90-day survival was greater in the group of patients without nosocomial infection (log rank 27.55, P < 0.001). The dynamic modelling of 90-day mortality revealed that in the first week, cardiopulmonary bypass time (HR = 1.00, 95% CI 1.00-1.02, P < 0.001) and emergency surgery (HR = 0.12, 95% CI 0.04-0.37, P < 0.001) were the most important risk factors for mortality, while after the first week, nosocomial infection (HR = 6.23, 95% CI 2.49-15.63, P < 0.001) was the main risk factor, followed by cardiopulmonary bypass time (HR = 1.01, 95% CI 1.00-1.01, P = 0.001) and EuroSCORE (HR = 1.03, 95% CI 1.00-1.06, P = 0.008).

CONCLUSIONS

Nosocomial infections after cardiac surgery constitute the main independent risk factor for mortality after the first week of surgery. These data suggest that its prevention following cardiac surgery must be prioritised to improve patient outcomes.

Effect of Perioperative Subglottic Secretion Drainage on Ventilator-Associated Pneumonia After Cardiac Surgery: A Retrospective, Before-and-After Study

OBJECTIVES

Although postoperative subglottic secretion drainage prevents ventilator-associated pneumonia (VAP) after cardiac surgery, its role during the perioperative period is unclear. For the present study, the effect of subglottic secretion drainage during and after cardiac surgery on postoperative VAP was investigated.

DESIGN

Retrospective, single-center, before-and-after study.

SETTING

Perioperative care of cardiac surgical patients in a tertiary university hospital.

PARTICIPANTS

Adult patients who underwent cardiac surgery from January 2013-December 2018.

INTERVENTIONS

Conventional and subglottic suctioning endotracheal tubes were used in the control and intervention groups before and after a change in institutional policy, respectively. In the intervention group, subglottic secretion drainage was performed continuously during surgery and intermittently after surgery.

MEASUREMENTS AND MAIN RESULTS

The risk of postoperative VAP, identified by the National Healthcare Safety Network surveillance definition algorithm, was compared by weighted logistic regression. Logistic regression analyses, with propensity score matching and inverse probability weighting, also were performed. A total of 2,576 patients were analyzed (control [n = 2108]; intervention [n = 468]). Postoperative VAP occurred less frequently in the intervention group (1/468 [0.2%]) compared with the control group (30/2,108 [1.4%]). In the multivariate weighted logistic regression analysis, the risk of VAP after cardiac surgery was significantly lower in the intervention group than in the control group (odds ratio 0.29; 95% confidence interval 0.14-0.58). Similar results were obtained in multivariate analyses after propensity score matching (odds ratio 0.04; 95% confidence interval 0.01-0.14) and inverse probability weighting (odds ratio 0.16; 95% confidence interval 0.05-0.42).

CONCLUSIONS

Routine perioperative subglottic secretion drainage using subglottic suctioning endotracheal tubes in patients undergoing cardiac surgery was associated with a reduction in the risk of VAP after surgery.

Comparison of Pseudomonas aeruginosa strains reveals that Exolysin A toxin plays an additive role in virulence

BACKGROUND

Pseudomonas aeruginosa possesses an array of virulence genes ensuring successful infection development. A two-partner secretion system Exolysin BA (ExlBA) is expressed in the PA7-like genetic outliers consisting of ExlA, a pore-forming toxin and ExlB transporter protein. Presence of exlBA in multidrug-resistant (MDR) strains has not been investigated, particularly in the strains isolated from wounded soldiers.

METHODS

We screened whole genome sequences of 2439 MDR- P. aeruginosa strains for the presence of exlBA. We compiled all exlBA positive strains and compared them with a diversity set for demographics, antimicrobial profiles and phenotypic characteristics: surface motility, biofilm formation, pyocyanin production and hemolysis. We compared the virulence of strains with comparable phenotypic characteristics in Galleria mellonella.

RESULTS

We identified 33 exlBA-positive strains (1.5%). These strains have increased antibiotic resistance, they are more motile, produce more robust biofilms and have comparable pyocianin production with the diversity set despite the phenotypic differences within the group. In in vivo infection models, these strains were less virulent than Type III Secretion System (T3SS) positive counterparts.

CONCLUSIONS

exlBA-positive strains are wide spread among the PA7-like outliers. While not as virulent as strains possessing T3SS, these strains exhibit phenotypic features associated with virulence and are still lethal in vivo.

Preoperative Treatment of Malnutrition and Sarcopenia in Cardiac Surgery: New Frontiers

Cardiac surgery is performed more often in a population with an increasing number of comorbidities. Although these surgeries can be lifesaving, they disturb homeostasis and may induce a temporary overall loss of physiologic function. The required postoperative intensive care unit and hospital stay often lead to a mid- to long-term decline of nutritional and physical status, mental health, and health-related quality of life. Prehabilitation before elective surgery might be an opportunity to optimize the state of the patient. This article discusses current evidence and potential effects of preoperative optimization of nutrition and physical status before cardiac surgery.

Seasonality of postoperative pneumonia after coronary artery bypass grafting: A national inpatient sample study

BACKGROUND

The development of postoperative pneumonia following cardiac surgery is associated with significant morbidity and mortality. However, seasonal variation as a risk factor for the development of postoperative pneumonia remains to be investigated. We sought to investigate whether patients undergoing coronary artery bypass grafting (CABG) during "flu season" (Fall and Winter months) at increased risk of postoperative pneumonia.

MATERIALS AND METHODS

A retrospective cohort study of patients undergoing CABG in the National Inpatient Sample between 2005 and 2015 was completed. Concomitant diagnosis of pneumonia was defined as the primary outcome. Secondary outcomes were defined to include pneumonia secondary to several known pathogens. Outcomes with significant differences between Fall/Winter and Spring/Summer groups were further analyzed with additive time series decomposition. Odds ratios were generated and adjusted for age, sex, elective status, and 29 other Agency for Healthcare Research and Quality comorbidity measures.

RESULTS

A total of 238 757 and 277 941 patients undergoing CABG during Fall/Winter and Spring/Summer, respectively, were identified. A significantly increased risk of postoperative pneumonia (adjusted odds ratio [aOR] = 1.15) and infection with influenza (aOR = 4.08), Haemophilus influenzae (aOR = 1.40), and Streptococcus pneumoniae (aOR = 1.47) was observed among patients receiving CABG in Q1 (January-March) compared to Q3 (July-September).

CONCLUSIONS

There is a strong seasonality in the incidence of postoperative pneumonia after CABG which may persist across other cardiothoracic surgeries. In addition to optimizing infection control and perioperative care, cardiac surgeons should consider preoperative vaccination against seasonal influenza, H. influenzae, and S. pneumoniae to improve outcomes among high-risk patients.