Postoperative pulmonary complications following cardiac surgery: the VENICE international cohort study

Negative extra-abdominal pressure (NEXAP)-based lung recruitment maneuver versus standard lung recruitment maneuver in the treatment of postoperative atelectasis after cardiac surgery: A single-center randomized controlled trial

OBJECTIVE

To evaluate the effect of negative extra-abdominal pressure (NEXAP)-based lung recruitment maneuver (LRM) for atelectasis after cardiac surgery, and compare it with stepwise positive end-expiratory pressure (PEEP)-based LRM.

METHODS

In this single-center randomized controlled clinical trial, patients were assigned to the NEXAP or PEEP groups. The primary outcome was the lung ultrasound score (LUSS) on global (LUSStot) and regional (LUSSp, posterior, LUSSa, anterior and LUSSl, lateral regions).

RESULTS

29 patients in the NEXAP group and 33 patients in the PEEP group were analyzed. The LUSStot was significantly decreased after LRM in both the NEXAP group (20.7 ± 3.2 vs. 15.6 ± 3.3; p < 0.001) and PEEP group (21.5 ± 4.2 vs. 17.1 ± 4.6; p < 0.001), and ΔLUSStot was significantly greater in the NEXAP group than PEEP group (-5.1 ± 2.3 vs. -3.8 ± 2.2, p = 0.020). Regional LUSS showed that NEXAP reduced LUSSl and LUSSp. PaO2/FiO2, PaO2, Vt, and Crs were significantly improved in the two groups.

CONCLUSION

NEXAP is an effective treatment for atelectasis after cardiac surgery, which significantly reduced patients' LUSS, improved pulmonary ventilation (especially in the lateral and posterior regions). NEXAP can further reduce LUSStot than the traditional PEEP-based LRM. Regional LUSS analyses reflecting the different mechanisms between the two methods of LRMs may require further investigation.

Intraoperative phrenic nerve stimulation to prevent diaphragm fiber weakness during thoracic surgery

Thoracic surgery rapidly induces weakness in human diaphragm fibers. The dysfunction is thought to arise from combined effects of the surgical procedures and inactivity. This project tested whether brief bouts of intraoperative hemidiaphragm stimulation would mitigate slow and fast fiber loss of force in the human diaphragm. We reasoned that maintenance of diaphragm activity with brief bouts of intraoperative phrenic stimulation would mitigate diaphragm fiber weakness and myofilament protein derangements caused by thoracic surgery. Nineteen adults (9 females, age 59 ± 12 years) with normal inspiratory strength or spirometry consented to participate. Unilateral phrenic twitch stimulation (twitch duration 1.5 ms, frequency 0.5 Hz, current 2x the motor threshold, max 25 mA) was applied for one minute, every 30 minutes during cardiothoracic surgery. Thirty minutes following the last stimulation bout, biopsies were obtained from the hemidiaphragms for single fiber force mechanics and quantitation of myofilament proteins (abundance and phosphorylation) and compared by a linear mixed model and paired t-test, respectively. Subjects underwent 6 ±  2 hemidiaphragm stimulations at 17 ±  6 mA, during 278 ±  68 minutes of surgery. Longer-duration surgeries were associated with a progressive decline in diaphragm fiber force (p < 0.001). In slow-twitch fibers, phrenic stimulation increased absolute force (+25%, p <  0.0001), cross-sectional area (+16%, p < 0.0001) and specific force (+7%, p < 0.0005). Stimulation did not alter contractile function of fast-twitch fibers, calcium-sensitivity in either fiber type, and abundance and phosphorylation of myofilament proteins. In adults without preoperative weakness or lung dysfunction, unilateral phrenic stimulation mitigated diaphragm slow fiber weakness caused by thoracic surgery, but had no effect on myofilament protein abundance or phosphorylation.

Off-pump versus on-pump coronary artery bypass grafting in patients with chronic obstructive pulmonary disease: a systematic review and meta-analysis

INTRODUCTION

Off-pump coronary artery bypass graft surgery (OPCAB) has been suggested as superior to on-pump coronary artery bypass graft surgery (ONCAB) in certain high-risk subgroups, but its benefit in patients with chronic obstructive pulmonary disease (COPD) remains controversial. This meta-analysis aimed to evaluate OPCAB versus ONCAB outcomes in COPD patients.

METHODS

We followed PRISMA guidelines and searched PubMed, Embase, and the Cochrane Library in August 2024 for studies comparing OPCAB and ONCAB in COPD patients. Statistical analysis was conducted using Review Manager 5.4.1 and Rstudio with a fixed or random effects model.

RESULTS

Six studies with a total of 1,687 patients were included, of which 1,062 (62.95%) underwent OPCAB. The mean patient age was 63.6 years. OPCAB did not significantly affect all-cause mortality compared to ONCAB (OR 1.14; 95% CI 0.65-1.99). There were no significant differences in reintubation (OR 0.81; 95% CI 0.53-1.23), prolonged ventilation (OR 0.54; 95% CI 0.24-1.22), post-operative atrial fibrillation (OR 0.90; 95% CI 0.70-1.15), or ARDS (OR 0.43; 95% CI 0.14-1.33). However, ventilation time was significantly shorter in the OPCAB group (MD - 5.30 h; 95% CI - 7.22 to - 3.38).

CONCLUSION

OPCAB is associated with reduced ventilation time in COPD patients though it shows no significant difference in all-cause mortality or other post-operative complications compared to ONCAB.

Exploring the assessment of post-cardiac valve surgery pulmonary complication risks through the integration of wearable continuous physiological and clinical data

BACKGROUND

Postoperative pulmonary complications (PPCs) following cardiac valvular surgery are characterized by high morbidity, mortality, and economic cost. This study leverages wearable technology and machine learning algorithms to preoperatively identify high-risk individuals, thereby enhancing clinical decision-making for the mitigation of PPCs.

METHODS

A prospective study was conducted at the Department of Cardiovascular Surgery of West China Hospital, Sichuan University, from August 2021 to December 2022. We examined 100 cardiac valvular surgery patients, where wearable technology was utilized to collect and analyze nocturnal physiological data at the 24-hour admission, in conjunction with clinical data extraction from the Hospital Information System's electronic records. We systematically evaluated three different input types (physiological, clinical, and both) and five classifiers (XGB, LR, RF, SVM, KNN) to identify the combination with strong predictive performance for PPCs. Feature selection was conducted using Recursive Feature Elimination with Cross-Validated (RFECV) for each model, yielding an optimal feature subset for each, followed by a grid search to tune hyperparameters. Stratified 5-fold cross-validation was used to evaluate the generalization performance. The significance of AUC differences between models was tested using the DeLong test to determine the optimal prognostic model comprehensively. Additionally, univariate logistic regression analysis was conducted on the features of the best-performing model to understand the impact of individual feature on PPCs.

RESULTS

In this study, 22 patients (22%) developed PPCs. Across classifiers, models combining both physiological and clinical features performed better than physiological or clinical features alone. Specifically, including physiological data in the classification model improved AUC, ACC, F1, and precision by an average of 8.32%, 1.80%, 3.28% and 6.06% compared to using clinical data only. The XGB classifier, utilizing both dataset, achieved the highest performance with an AUC of 0.82 (± 0.08) and identified eight significant features. The DeLong test indicated that the XGB model utilizing the both dataset significantly outperformed the XGB models trained on the physiological or clinical datasets alone. Univariate logistic regression analysis suggested that surgical methods, age, nni_50, and min_ven_in_mean are significantly associated with the occurrence of PPCs.

CONCLUSION

The integration of continuous wearable physiological and clinical data significantly improves preoperative risk assessment for PPCs, which helps to optimize surgical management and reduce PPCs morbidity and mortality.

The effect of preoperative deep breathing exercise with incentive spirometer initiated in the preoperative period on respiratory parameters and complications in patients underwent open heart surgery: a randomized controlled trial

BACKGROUND

Incentive spirometer is used in lung expansion therapy to maintain alveolar patency and improve pulmonary volumes in postoperative cardiac surgical patients. Deep breathing exercises with an incentive spirometer significantly reduce the development of postoperative pulmonary complications after open-heart cardiac surgery.

AIM

To determine the effect of deep breathing exercises with an incentive spirometer initiated in the preoperative period on respiratory parameters and complications in patients who underwent open-heart surgery.

METHODS

This randomized controlled study was conducted with a total of 66 participants. The participants were randomized into a deep breathing group (n = 32) and a control group (n = 34). The control group received hospital routine physiotherapy, and the deep breathing group started to perform deep breathing exercises with an incentive spirometer in the preoperative period. Data were collected with the Sociodemographic and Medical Data Form and Patient Follow-up Form (respiratory rate, oxygen saturation (SpO2) level, arterial blood gas parameters and posteroanterior chest X-ray were monitored with this form prepared by the investigators). The Medical Research Council Scale was used to determine the severity of dyspnea in the patients included in the study. Primary outcomes included respiratory rate, oxygen saturation, arterial blood gas parameters, posteroanterior chest X-ray, and evaluation of postoperative pulmonary complications development. Secondary outcomes included the mechanical ventilation time, length of intensive care unit stay, and length of hospital stay.

RESULTS

The incidence of postoperative pulmonary complications was 3.1% and 23.5% (p < 0.05) in the deep breathing and control groups, respectively. The mechanical ventilation time, length of hospital stay, and length of stay in the intensive care unit were significantly shorter in the deep breathing group (p < 0.05). In the deep breathing group, the mean SpO2 values evaluated before surgery, on the first day in the Cardiovascular Surgery Unit, and on the day of discharge were significantly higher than the control group (p < 0.05).

CONCLUSION

Deep breathing exercises with an incentive spirometer initiated in the preoperative period contribute to a reduction in postoperative pulmonary complication rates, shortening of mechanical ventilation time, length of stay in the intensive care unit, length of hospital stay, and improvement of pre- and postoperative oxygenation.

TRIAL REGISTRATION

The trial was registered on June 17, 2022, at https://www.

CLINICALTRIALS

gov/ , registration number NCT05428722.

Factors related to cough strength before tracheal extubation in post-cardiac surgery patients: A cross-sectional study

BACKGROUND

Tracheal extubation failure after cardiac surgery is associated with diminished cough strength, albeit the information on cough strength in post-cardiac surgery patients is limited.

AIM

To investigate the cough strength in patients after cardiac surgery before tracheal extubation and the related influencing factors.

STUDY DESIGN

A cross-sectional study was designed, with adherence to the STROBE guidelines. The participants were 528 patients undergoing open-heart cardiac surgery who were admitted to the Cardio Surgical Centre in a tertiary hospital in Nanjing, China, from August 2022 to September 2023. Cough peak flow (CPF) ≤60 L/min set as the cut-off value for evaluating diminished cough strength before tracheal extubation. Univariate analysis and multiple linear regression analysis were used to analyse the related influencing factors.

RESULTS

The mean CPF was 130.70 ± 50.58 L/min. A total of 76 (14.4%) patients exhibited a CPF of ≤60 L/min. Multiple linear regression analysis revealed that gender (B = 14.266, t = 2.456, p = .014), inspiratory capacity (IC) (B = 0.013, t = 3.755, p < .001), preoperative CPF (B = 0.086, t = 3.903, p < .001), muscle strength (B = 12.423, t = 4.242, p < .001), preoperative exercise regimen (B = 16.716, t = 4.236, p < .001) and pain levels (B = -8.115, t = -5.794, p < .001) significantly contributed to cough strength.

CONCLUSIONS

Female gender, lower upper limb muscle strength, higher pain levels, lower preoperative CPF and IC, and the absence of systematic exercise were found to be associated with diminished cough strength.

RELEVANCE TO CLINICAL PRACTICE

Cough strength provides important auxiliary data in extubation decision-making. In addition, understanding its relevant factors can help identify the high-risk group of tracheal extubation failure and can help provide a strong theoretical basis for the development of personalized interventions.

Frequency and Predictors of Pneumonia After Isolated Coronary Artery Bypass Grafting (CABG): A Single-Center Study

Background: CABG is a commonly performed procedure to improve survival and quality of life in patients with coronary artery disease. Despite advances in surgical techniques and perioperative care, postoperative pneumonia remains a serious complication contributing to increased morbidity, mortality and healthcare costs. This study aims to evaluate the incidence of postoperative pneumonia (POP) and identify its risk factors in patients undergoing isolated CABG. Methods: This retrospective study analyzed 430 patients who underwent CABG between 2019 and 2024. Patient demographics, clinical characteristics, surgical details and laboratory data were collected. Statistical analysis included univariate and multivariate logistic regression to identify significant predictors of pneumonia. Results: The incidence of POP after CABG was 10% (43/430). In patients with POP, diabetes mellitus (p = 0.03) and chronic kidney disease (p = 0.048) prevalence was higher, cardiopulmonary bypass (CPB) (p = 0.01) and cross-clamp time (p = 0.003) was longer, LDH levels (p = 0.017) were higher, hemoglobin (p = 0.012) and albumin (p = 0.015) levels were lower, and lymphocyte % (p = 0.04) was lower; prevalence of COPD and length of stay (LOS) in hospital tended to be higher (both p < 0.06). Multivariate binary logistic regression identified COPD (OR 4.383, 95% CI: 1.106-17.363, p = 0.035), CPB time (OR 1.013, 95% CI: 1.001-1.025, p = 0.030) and LOS (OR 1.052, 95% CI: 1.004-1.103, p = 0.035) as independent predictors of POP. Conclusions: Postoperative pneumonia is a common complication after CABG and is strongly associated with preoperative COPD, CPB time and length of stay in hospital. These findings underline the importance of preoperative risk assessment and optimization. Early identification of high-risk patients may allow targeted strategies such as enhanced respiratory support and prophylactic antibiotics to reduce the incidence of pneumonia and improve clinical outcomes.

The Effects of Seasonal Variation on the Outcomes of Patients Undergoing Off-Pump Coronary Artery Bypass Grafting

Background

The impact of seasonal patterns on the mortality and morbidity of surgical patients with cardiovascular diseases has gained increasing attention in recent years. However, whether this seasonal variation extends to cardiovascular surgery outcomes remains unknown. This study sought to evaluate the effects of seasonal variation on the short-term outcomes of patients undergoing off-pump coronary artery bypass grafting (OPCABG).

Methods

This study identified all patients undergoing elective OPCABG at a single cardiovascular center between January 2020 and December 2020. Patients were divided into four groups according to the season of their surgery. The primary outcome was the composite incidence of mortality and morbidity during hospitalization. Secondary outcomes included chest tube drainage (CTD) within 24 h, total CTD, chest drainage duration, mechanical ventilation duration, and postoperative length of stay (LOS) in the intensive care unit (ICU) and hospital.

Results

Winter and spring surgeries were associated with higher composite incidence of mortality and morbidities (26.8% and 18.0%) compared to summer (15.7%) and autumn (11.1%) surgeries (p < 0.05). Spring surgery had the highest median CTD within 24 hours after surgery (640 mL), whereas it also exhibited the lowest total CTD (730 mL) (p < 0.05). Chest drainage duration was longer in spring and summer than in autumn and winter (p < 0.05). While no significant differences were observed in mechanical ventilation duration and hospital stay among the four seasons, the LOS in the ICU was longer in summer than in autumn (88 h vs. 51 h, p < 0.05).

Conclusions

The OPCABG outcomes might exhibit seasonal patterns in patients with coronary heart disease.

ERS statement on benign pleural effusions in adults

The incidence of non-malignant pleural effusions far outweighs that of malignant pleural effusions and is estimated to be at least 3-fold higher. These so-called benign effusions do not follow a "benign course" in many cases, with mortality rates matching and sometimes exceeding those of malignant pleural effusions. In addition to the impact on patients, healthcare systems are also significantly affected, with recent US epidemiological data demonstrating that 75% of resource allocation for pleural effusion management is spent on non-malignant pleural effusions (excluding empyema). Despite this significant burden of disease, and by existing at the junction of multiple medical specialties, reflecting a heterogenous constellation of medical conditions, non-malignant pleural effusions are rarely the focus of research or the subject of management guidelines. With this European Respiratory Society Task Force, we assembled a multispecialty collaborative across 11 countries and three continents to provide a statement based on systematic searches of the medical literature to highlight evidence in the management of the following clinical areas: a diagnostic approach to transudative effusions, heart failure, hepatic hydrothorax, end-stage renal failure, benign asbestos-related pleural effusion, post-surgical effusion and nonspecific pleuritis.

Benefits from Implementing Low- to High-Intensity Inspiratory Muscle Training in Patients Undergoing Cardiac Surgery: A Systematic Review

Cardiac surgery procedures are among the main treatments for people with cardiovascular disease, with physiotherapy playing a vital part. Respiratory complications are common and associated with prolonged Intensive Care Unit (ICU) and hospital stay, as well as increased mortality. Inspiratory muscle training has been found to be beneficial in improving respiratory muscle function in critically ill patients and patients with heart failure. The purpose of this review is to present the results of implementing inspiratory muscle training (IMT) programs in patients before and/or after cardiac surgery. The PubMed, Embase and Science Direct databases were searched from January 2012 to August 2023. In the present review, randomized controlled clinical trials (RCTs), clinical trials and quasi-experimental studies conducted in adult patients pre and/or post cardiac surgery were included. Fifteen studies were considered eligible for inclusion in the review. The results revealed that the IMT programs varied in intensity, repetitions, and duration in all included studies. Most studies implemented the IMT after the surgery. Statistical significance between groups was noted in Maximal Inspiratory Pressure and the 6-Minute Walk Distance Test. Preoperative and postoperative programs could improve inspiratory muscle strength, pulmonary function, and functional capacity as well as decrease the length of hospital stay in patients undergoing cardiac surgery. No clear evidence emerged favoring low or higher IMT intensities. The combination of IMT with other forms of exercise might be beneficial in patients undergoing cardiac surgery. However, further RCTs are required to provide confirming evidence.

Development and validation of prediction model for prolonged mechanical ventilation after total thoracoscopic valve replacement: a retrospective cohort study

Total thoracoscopic valve replacement (TTVR) is a minimally invasive alternative to traditional open-heart surgery. However, some patients undergoing TTVR experience prolonged mechanical ventilation (PMV). Predicting PMV risk is crucial for optimizing perioperative management and improving outcomes. We conducted a retrospective cohort study of 2,319 adult patients who underwent TTVR at a tertiary care center between January 2017 and May 2024. PMV was defined as mechanical ventilation exceeding 72 h post-surgery. A Fine-Gray competing risks regression model was developed and validated to identify predictors of PMV. Significant predictors of PMV included cardiopulmonary bypass time, ejection fraction, New York Heart Association grading, serum albumin, atelectasis, pulmonary infection, pulmonary edema, age, need for postoperative dialysis, hemoglobin levels, and PaO2/FiO2. The model demonstrated good discriminative ability, with areas under the receiver operating characteristic curves of 0.747 in the training set and 0.833 in the validation set. Calibration curves showed strong agreement between predicted and observed PMV probabilities. Decision curve analysis indicated clinical utility across a range of threshold probabilities. Our predictive model for PMV following TTVR demonstrates strong performance and clinical utility. It helps identify high-risk patients and tailor perioperative management to reduce PMV risk and improve outcomes. Further validation in diverse settings is recommended.

Identifying Early Risk Factors for Postoperative Pulmonary Complications in Cardiac Surgery Patients

Background and Objectives: Postoperative pulmonary complications (PPCs) are common in patients who undergo cardiac surgery and are widely acknowledged as significant contributors to increased morbidity, mortality rates, prolonged hospital stays, and healthcare costs. Clinical manifestations of PPCs can vary from mild to severe symptoms, with different radiological findings and varying incidence. Detecting early signs and identifying influencing factors of PPCs is essential to prevent patients from further complications. Our study aimed to determine the frequency, types, and risk factors significant for each PPC on the first postoperative day. The main goal of this study was to identify the incidence of pleural effusion (right-sided, left-sided, or bilateral), atelectasis, pulmonary edema, and pneumothorax as well as detect specific factors related to its development. Materials and Methods: This study was a retrospective single-center trial. It involved 314 adult patients scheduled for elective open-heart surgery under CPB. Results: Of the 314 patients reviewed, 42% developed PPCs within 12 h post-surgery. Up to 60.6% experienced one PPC, while 35.6% developed two PPCs. Pleural effusion was the most frequently observed complication in 89 patients. Left-sided effusion was the most common, presenting in 45 cases. Regression analysis showed a significant association between left-sided pleural effusion development and moderate hypoalbuminemia. Valve surgery was associated with reduced risk for left-sided effusion. Independent parameters for bilateral effusion include increased urine output and longer ICU stays. Higher BMI was inversely related to the risk of pulmonary edema. Conclusions: At least one PPC developed in almost half of the patients. Left-sided pleural effusion was the most common PPC, with hypoalbuminemia as a risk factor for effusion development. Atelectasis was the second most common. Bilateral effusion was the third most common PPC, significantly related to increased urine output. BMI was an independent risk factor for pulmonary edema development.

First initiation of mobilization out of bed after cardiac surgery - an observational cross-sectional study in Sweden

BACKGROUND

Cardiac surgery is associated with a period of postoperative bed rest. Although early mobilization is a vital component of postoperative care, for preventing complications and enhancing physical recovery, there is limited data on routine practices and optimal strategies for early mobilization after cardiac surgery. The aim of the study was to define the timing for the first initiation of out of bed mobilization after cardiac surgery and to describe the type of mobilization performed.

METHODS

In this observational study, the first mobilization out of bed was studied in a subset of adult cardiac surgery patients (n = 290) from five of the eight university hospitals performing cardiothoracic surgery in Sweden. Over a five-week period, patients were evaluated for mobilization routines within the initial 24 h after cardiac surgery. Data on the timing of the first mobilization after the end of surgery, as well as the duration and type of mobilization, were documented. Additionally, information on patient characteristics, anesthesia, and surgery was collected.

RESULTS

A total of 277 patients (96%) were mobilized out of bed within the first 24 h, and 39% of these patients were mobilized within 6 h after surgery. The time to first mobilization after the end of surgery was 8.7 ± 5.5 h; median of 7.1 [4.5-13.1] hours, with no significant differences between coronary artery bypass grafting, valve surgery, aortic surgery or other procedures (p = 0.156). First mobilization session lasted 20 ± 41 min with median of 10 [1-11]. Various kinds of first-time mobilization, including sitting on the edge of the bed, standing, and sitting in a chair, were revealed. A moderate association was found between longer intubation time and later first mobilization (ρ = 0.487, p < 0.001). Additionally, there was a moderate correlation between the first timing of mobilization duration of the first mobilization session (ρ = 0.315, p < 0.001).

CONCLUSIONS

This study demonstrates a median time to first mobilization out of bed of 7 h after cardiac surgery. A moderate correlation was observed between earlier timing of mobilization and shorter duration of the mobilization session. Future research should explore reasons for delayed mobilization and investigate whether earlier mobilization correlates with clinical benefits.

TRIAL REGISTRATION

FoU in VGR (Id 275,357) and Clinical Trials (NCT04729634).

Opioid-free anaesthesia with dexmedetomidine and lidocaine versus remifentanil-based anaesthesia in cardiac surgery: study protocol of a French randomised, multicentre and single-blinded OFACS trial

INTRODUCTION

Intraoperative opioids have been used for decades to reduce negative responses to nociception. However, opioids may have several, and sometimes serious, adverse effects. Cardiac surgery exposes patients to a high risk of postoperative complications, some of which are common to those caused by opioids: acute respiratory failure, postoperative cognitive dysfunction, postoperative ileus (POI) or death. An opioid-free anaesthesia (OFA) strategy, based on the use of dexmedetomidine and lidocaine, may limit these adverse effects, but no randomised trials on this issue have been published in cardiac surgery.We hypothesised that OFA versus opioid-based anaesthesia (OBA) may reduce the incidence of major opioid-related complications after cardiac surgery.

METHODS AND ANALYSIS

Multicentre, randomised, parallel and single-blinded clinical trial in four cardiac surgical centres in France, including 268 patients scheduled for coronary artery bypass grafting under cardiac bypass, with or without aortic valve replacement. Patients will be randomised to either a control OBA protocol using remifentanil or an OFA protocol using dexmedetomidine/lidocaine. The primary composite endpoint is the occurrence of at least one of the following: (1) postoperative cognitive disorder evaluated by the Confusion Assessment Method for the Intensive Care Unit test, (2) POI, (3) acute respiratory distress or (4) death within the first 48 postoperative hours. Secondary endpoints are postoperative pain, morphine consumption, nausea-vomiting, shock, acute kidney injury, atrioventricular block, pneumonia and length of hospital stay.

ETHICS AND DISSEMINATION

This trial has been approved by an independent ethics committee (Comité de Protection des Personnes Ouest III-Angers on 23 February 2021). Results will be submitted in international journals for peer reviewing.

TRIAL REGISTRATION NUMBER

NCT04940689, EudraCT 2020-002126-90.

Association of point-of-care lung ultrasound findings with 30-day pulmonary complications after cardiac surgery: A prospective cohort study

Background

Several studies have shown that bedside lung ultrasound findings in postanaesthesia care units (PACUs) and intensive care units (ICUs) correlate with postoperative pulmonary complications(PPCs) after noncardiac major surgery. However, it remains unclear whether lung ultrasound findings can be used as early predictors of PPCs in patients undergoing cardiac surgery. The main aim of our study was to evaluate the relationship between early postoperative point-of-care lung ultrasound findings and PPCs after cardiac surgery.

Methods

Two board-certified physicians performed a point-of-care pulmonary ultrasound on cardiac surgery patients approximately 2 h after the patient was admitted to the ICU. Pulmonary complications occurring within 30 days postoperatively were recorded. Logistic regression modeling was used to analyze the relationship between lung ultrasound findings and PPCs.

Results

PPCs occurred in 61 (30.9 %) of the 197 patients. Lung ultrasound scores(LUS), number of lung consolidation(NLC), and depth of pleural effusion(DPE) were more significant in patients who developed PPCs (P < 0.001). According to the multivariate analysis, NLC≥3(aOR 2.71,95%CI 1.14-6.44; p = 0.024)and DPE >0.95(aOR 3.79,95%CI 1.60-8.99; p = 0.002) were found to be independently associated with PPCs during this study.

Conclusions

Our study demonstrated that DPE >0.95 and NLC ≥3 were associated with PPCs after cardiac surgery based on bedside lung ultrasound findings in the ICU. When these signs manifest perioperatively, the surgeon should be alerted and the necessary steps should be taken, especially if they present simultaneously.

Con: Mechanical Ventilation During Cardiopulmonary Bypass

The ventilatory strategy to adopt during cardiopulmonary bypass is still being debated. The rationale for using continuous positive airway pressure or mechanical ventilation would be to counteract alveolar collapse and improve ischemia phenomena and passive alveolar diffusion of oxygen. Although there are several studies supporting the hypothesis of a positive effect on oxygenation and systemic inflammatory response, the real clinical impact of ventilation during cardiopulmonary bypass is controversial. Furthermore, the biases present in the literature make the studies' results nonunique in their interpretation.

Identifying High-Risk Patients for Severe Pulmonary Complications after Cardiosurgical Procedures as a Target Group for Further Assessment of Lung-Protective Strategies

OBJECTIVES

It remains unclear whether intraoperative lung-protective strategies can reduce the rate of respiratory complications after cardiac surgery, partly because low-risk patients have been studied in the past. The authors established a screening model to easily identify a high-risk group for severe pulmonary complications (ie, pneumonia or acute respiratory distress syndrome) that may be the ideal target population for the assessment of the potential benefits of such measures.

DESIGN

Retrospective observational trial.

SETTING

Departments of cardiac surgery and cardiac anesthesia of a university hospital.

PARTICIPANTS

Consecutive patients undergoing cardiac surgery on cardiopulmonary bypass and subsequent treatment at a dedicated cardiosurgical intensive care unit between January 2019 and March 2021.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of the 2,572 patients undergoing surgery, 84 (3.3%) developed pneumonia/acute respiratory distress syndrome that significantly affected the outcome (ie, longer ventilatory support [66% vs 11%], higher reintubation rate [39% vs 3%]), prolonged length of intensive care unit [33 ± 36 vs 4 ± 10 days] and hospital stay [10 ± 15 vs 6 ± 7 days], and higher in-hospital [43% vs 9%] as well as 30-day [7% vs 3%] mortality). The screening model for severe pulmonary complications included left ventricular ejection fraction <52%, EuroSCORE II (European System for Cardiac Operative Risk Evaluation II) >5.9, cardiopulmonary bypass time >123 minutes, left ventricular assist device or aortic repair surgery, and bronchodilatory therapy. A cutoff for the predicted risk of 2.5% showed optimal sensitivity and specificity, with an area under the receiver operating characteristic curve of 0.82.

CONCLUSIONS

The authors suggest that future research on intraoperative lung-protective measures focuses on this high-risk population, primarily aiming to mitigate severe forms of postoperative pulmonary dysfunction associated with poor outcomes and increased resource consumption.

Effect of Mechanical Ventilation Mode Type on Postoperative Pulmonary Complications After Cardiac Surgery: A Randomized Controlled Trial

OBJECTIVES

It is unknown whether there is a difference in pulmonary outcome in different intraoperative ventilation modes for cardiac surgery with cardiopulmonary bypass (CPB). The aim of this trial was to determine whether patients undergoing cardiac surgery with CPB could benefit from intraoperative optimal ventilation mode.

DESIGN

This was a single-center, prospective, randomized controlled trial.

SETTING

The study was conducted at a single-center tertiary-care hospital.

PARTICIPANTS

A total of 1,364 adults undergoing cardiac surgery with CPB participated in this trial.

INTERVENTIONS

Patients were assigned randomly (1:1:1) to receive 1 of 3 ventilation modes: volume-controlled ventilation (VCV), pressure-controlled ventilation (PCV), and pressure-controlled ventilation-volume guaranteed (PCV-VG). All arms of the study received the lung-protective ventilation strategy.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was a composite of postoperative pulmonary complications (PPCs) within the first 7 postoperative days. Pulmonary complications occurred in 168 of 455 patients (36.9%) in the PCV-VG group, 171 (37.6%) in the PCV group, and 182 (40.1%) in the VCV group, respectively. There was no statistical difference in the risk of overall pulmonary complications among groups (p = 0.585). There were no significant differences in the severity grade of PPCs within 7 days, postoperative ventilation duration, intensive care unit stay, postoperative hospital stay, or 30-day postoperative mortality.

CONCLUSIONS

Among patients scheduled for cardiac surgery with CPB, intraoperative ventilation mode type did not affect the risk of postoperative pulmonary complications.

Residual Neuromuscular Block Remains a Safety Concern for Perioperative Healthcare Professionals: A Comprehensive Review

Residual neuromuscular block (RNMB) remains a significant safety concern for patients throughout the perioperative period and is still widely under-recognized by perioperative healthcare professionals. Current literature suggests an association between RNMB and an increased risk of postoperative pulmonary complications, a prolonged length of stay in the post anesthesia care unit (PACU), and decreased patient satisfaction. The 2023 American Society of Anesthesiologists Practice Guidelines for Monitoring and Antagonism of Neuromuscular Blockade provide guidance for the use of quantitative neuromuscular monitoring coupled with neuromuscular reversal to recognize and reduce the incidence of RNMB. Using sugammadex for the reversal of neuromuscular block as well as quantitative neuromuscular monitoring to quantify the degree of neuromuscular block may significantly reduce the risk of RNMB among patients undergoing general anesthesia. Studies are forthcoming to investigate how using neuromuscular blocking agent reversal with quantitative monitoring of the neuromuscular block may further improve perioperative patient safety.

Personalized Noninvasive Respiratory Support in the Perioperative Setting: State of the Art and Future Perspectives

Background: Noninvasive respiratory support (NRS), including high-flow nasal oxygen therapy (HFNOT), noninvasive ventilation (NIV) and continuous positive airway pressure (CPAP), are routinely used in the perioperative period. Objectives: This narrative review provides an overview on the perioperative use of NRS. Preoperative, intraoperative, and postoperative respiratory support is discussed, along with potential future areas of research. Results: During induction of anesthesia, in selected patients at high risk of difficult intubation, NIV is associated with improved gas exchange and reduced risk of postoperative respiratory complications. HFNOT demonstrated an improvement in oxygenation. Evidence on the intraoperative use of NRS is limited. Compared with conventional oxygenation, HFNOT is associated with a reduced risk of hypoxemia during procedural sedation, and recent data indicate a possible role for HFNOT for intraoperative apneic oxygenation in specific surgical contexts. After extubation, "preemptive" NIV and HFNOT in unselected cohorts do not affect clinical outcome. Postoperative "curative" NIV in high-risk patients and among those exhibiting signs of respiratory failure can reduce reintubation rate, especially after abdominal surgery. Data on postoperative "curative" HFNOT are limited. Conclusions: There is increasing evidence on the perioperative use of NRS. Use of NRS should be tailored based on the patient's specific characteristics and type of surgery, aimed at a personalized cost-effective approach.

Functional capacity in smoking patients after coronary artery bypass grafting surgery: a quasi-experimental study

Coronary artery bypass grafting surgery (CABG) is an important approach to treating coronary heart disease. However, patients undergoing open heart surgery are at risk of postoperative complications. Cigarette smoking is one of the preoperative risk factors that may increase postoperative complications. Studies show that early mobilization intervention may reduce these complications and improve functional capacity, but the impact of smoking on early outcomes after CABG has been controversial for the past two decades. This quasi-experimental study explored the effects of early mobilization on functional capacity among patients with different smoking histories undergoing CABG. The study involved 51 participants who underwent CABG surgery, divided into three groups: current smokers, former smokers, and non-smokers (n=17 each). A day before surgery, all groups underwent a six-minute walking test (6MWT). Every participant received the same intervention after surgery, including deep breathing exercises, an upper limb range of motion assessment, an incentive spirometer, and walking with and without assistance. Five days postoperatively, all outcomes - including the 6MWT, length of stay (LOS) in the ICU, and postoperative pulmonary complications - were assessed, and the 6MWT was repeated. There was a reduced functional capacity after CABG in ex-smokers (215.8±102 m) and current smokers (272.7±97m) compared to non-smokers (298.5±97.1m) in terms of 6MWT (p<0.05). Current smokers were more likely to have atelectasis after CABG than ex-smokers (76.5% vs. 52.9%), with non-smokers being the least likely to have atelectasis among the three groups (29.4%, p<0.05). Additionally, current smokers required longer ventilator support post-CABG (11.9±7.3 hours) compared to ex-smokers (8.3±4.3 hours) and non-smokers (7±2.5 hours, p<0.01). Smoking status significantly impacts functional capacity reduction after CABG, with current smokers being more susceptible to prolonged ventilator use and atelectasis.

Association of preoperative frailty with pulmonary complications after cardiac surgery in elderly individuals: a prospective cohort study

BACKGROUND

The relationship between preoperative frailty and pulmonary complications after cardiac surgery in elderly patients is unclear. This study was designed to evaluate the relationship between frailty and postoperative pulmonary complications (PPCs) in elderly patients undergoing cardiac surgery and to provide a basis for their prevention and treatment.

AIMS

This study aimed to investigate the predictive value of preoperative frailty on pulmonary complications after cardiac surgery in elderly patients.

METHODS

Frailty was assessed using the CAF. The diagnosis of PPCs was based on the criteria defined by Hulzebos et al., and patients were classified into a PPCs group and a non-PPCs group. Factors with clinical significance and P < 0.05 in univariate regression analysis were included in multivariate logistic regression analysis to determine the relationship between preoperative frailty and PPCs. The area under the receiver operating characteristic (ROC) curve (AUC) was used to compare the predictive effects of the CAF, EuroSCORE II, and ASA + age on the occurrence of PPCs.

RESULTS

A total of 205 patients were enrolled in this study, 31.7% of whom developed PPCs. Univariate logistic regression analysis showed that frailty, ASA grade, EuroSCORE II, hemoglobin concentration, FVC, time of operation, and postoperative AKI were associated with the development of PPCs. However, after adjustments for all possible confounding factors, multivariate logistic regression results showed that frailty, prolonged operation time, and postoperative AKI were risk factors for PPCs, and the risk of postoperative PPCs in frail patients was approximately 4.37 times that in nonfrail patients (OR = 4.37, 95%CI: 1.6-11.94, P < 0.05). The predictive efficacy of the traditional perioperative risk assessment tools EuroSCORE II and ASA + age was lower than that of CAF.

CONCLUSIONS

Frailty before surgery, prolonged operation time, and postoperative AKI were independent risk factors for pulmonary complications after heart surgery in elderly individuals, and CAF was more effective than the traditional risk predictors EuroSCORE II and ASA + age.

The effect of driving pressure-guided versus conventional mechanical ventilation strategy on pulmonary complications following on-pump cardiac surgery: A randomized clinical trial

STUDY OBJECTIVE

Postoperative pulmonary complications occur frequently and are associated with worse postoperative outcomes in cardiac surgical patients. The advantage of driving pressure-guided ventilation strategy in decreasing pulmonary complications remains to be definitively established. We aimed to investigate the effect of intraoperative driving pressure-guided ventilation strategy compared with conventional lung-protective ventilation on pulmonary complications following on-pump cardiac surgery.

DESIGN

Prospective, two-arm, randomized controlled trial.

SETTING

The West China university hospital in Sichuan, China.

PATIENTS

Adult patients who were scheduled for elective on-pump cardiac surgery were enrolled in the study.

INTERVENTIONS

Patients undergoing on-pump cardiac surgery were randomized to receive driving pressure-guided ventilation strategy based on positive end-expiratory pressure (PEEP) titration or conventional lung-protective ventilation strategy with fixed 5 cmH2O of PEEP.

MEASUREMENTS

The primary outcome of pulmonary complications (including acute respiratory distress syndrome, atelectasis, pneumonia, pleural effusion, and pneumothorax) within the first 7 postoperative days were prospectively identified. Secondary outcomes included pulmonary complication severity, ICU length of stay, and in-hospital and 30-day mortality.

MAIN RESULTS

Between August 2020 and July 2021, we enrolled 694 eligible patients who were included in the final analysis. Postoperative pulmonary complications occurred in 140 (40.3%) patients in the driving pressure group and 142 (40.9%) in the conventional group (relative risk, 0.99; 95% confidence interval, 0.82-1.18; P = 0.877). Intention-to-treat analysis showed no significant difference between study groups regarding the incidence of primary outcome. The driving pressure group had less atelectasis than the conventional group (11.5% vs 17.0%; relative risk, 0.68; 95% confidence interval, 0.47-0.98; P = 0.039). Secondary outcomes did not differ between groups.

CONCLUSION

Among patients who underwent on-pump cardiac surgery, the use of driving pressure-guided ventilation strategy did not reduce the risk of postoperative pulmonary complications when compared with conventional lung-protective ventilation strategy.

Postoperative care after left ventricular assist device implantation: considerations for the cardiac surgical intensivist

Heart failure is a leading cause of morbidity and mortality, the incidence of which is predicted to continue to increase as the population ages. Left ventricular assist devices (LVADs) in particular have emerged as important therapies for the support of patients with advanced heart failure needing short- or long-term mechanical circulatory support. With over 5000 implantations per year, LVADs are the most commonly used durable devices worldwide. In this article, we provide an overview of the intensive care management of patients with LVADs during the early post-implantation period.

Effect of Active Physiotherapy With Positive Airway Pressure on Pulmonary Atelectasis After Cardiac Surgery: A Randomized Controlled Study

OBJECTIVES

The authors investigated the effect of active work with positive airway pressure (PAP) in addition to chest physiotherapy (CP) on pulmonary atelectasis (PA) in patients undergoing cardiac surgery with cardiopulmonary bypass.

DESIGN

A randomized controlled study.

SETTING

At a single-center tertiary hospital.

PARTICIPANTS

Eighty adult patients undergoing cardiac surgery (coronary artery bypass grafting, valve surgery, or both), and presenting with PA after tracheal extubation on postoperative days 1 or 2, were randomized from November 2014 to September 2016.

INTERVENTION

Three days of CP, twice daily, associated with active work with PAP effect (intervention group) versus CP alone (control group). Pulmonary atelectasis was assessed by using the radiologic atelectasis score (RAS) measured from daily chest x-rays. All radiographs were reviewed blindly.

MEASUREMENTS AND MAIN RESULTS

Among included patients, 79 (99%) completed the trial. The primary outcome was mean RAS on day 2 after inclusion. It was significantly lower in the intervention group (mean difference and 95% CI: -1.1 [-1.6 to -0.6], p < 0.001). The secondary outcomes were the sniff nasal inspiratory pressure measured before and after CP and clinical variables. Sniff nasal inspiratory pressure was significantly higher in the intervention group on day 2 (7.7 [3.0-12.5] cmH₂O, p = 0.002). The respiratory rate was lower in the intervention group (-3.2 [95% CI -4.8 to -1.6] breaths/min, p < 0.001) on day 2. No differences were found between the 2 groups for percutaneous oxygen saturation/oxygen requirement ratio, heart rate, pain, and dyspnea scores.

CONCLUSIONS

Active work with the PAP effect, combined with CP, significantly decreased the RAS of patients undergoing cardiac surgery after 2 days of CP, with no differences observed in clinically relevant parameters.

Balanced Nonopioid General Anesthesia With Lidocaine Is Associated With Lower Postoperative Complications Compared With Balanced Opioid General Anesthesia With Sufentanil for Cardiac Surgery With Cardiopulmonary Bypass: A Propensity Matched Cohort Study

BACKGROUND

There are no data on the effect of balanced nonopioid general anesthesia with lidocaine in cardiac surgery with cardiopulmonary bypass. The main study objective was to evaluate the association between nonopioid general balanced anesthesia and the postoperative complications in relation to opioid side effects.

METHODS

Patients undergoing cardiac surgery with cardiopulmonary bypass between 2019 and 2021 were identified. After exclusion of patients for heart transplantation, left ventricular assistance device, and off-pump surgery, we classified patients according to an opioid general balanced anesthesia or a nonopioid balanced anesthesia with lidocaine. The primary outcome was a collapsed composite of postoperative complications that comprise respiratory failure and confusion, whereas secondary outcomes were acute renal injury, pneumoniae, death, intensive care unit (ICU), and hospital length of stay.

RESULTS

We identified 859 patients exposed to opioid-balanced general anesthesia with lidocaine and 913 patients exposed to nonopioid-balanced general anesthesia. Propensity score matching yielded 772 individuals in each group with balanced baseline covariates. Two hundred thirty-six patients (30.5%) of the nonopioid-balanced general anesthesia versus 186 patients (24.1%) presented postoperative composite complications. The balanced lidocaine nonopioid general anesthesia group was associated with a lower proportion with the postoperative complication composite outcome OR, 0.72 (95% CI, 0.58-0.92; P = .027). The number of patients with acute renal injury, death, and hospital length of stay did not differ between the 2 groups.

CONCLUSIONS

A balanced nonopioid general anesthesia protocol with lidocaine was associated with lower odds of postoperative complication composite outcome based on respiratory failure and confusion.

A Retrospective Pilot Comparison Trial Investigating Clinical Outcomes in Cardiac Surgical Patients Who Received Sugammadex Reversal During 2018 to 2021

OBJECTIVES

To compare the number of eligible urgent and elective cardiac surgical patients who could be extubated successfully within 6 hours of surgery and who received sugammadex versus those who did not.

DESIGN

This retrospective pilot study compared outcomes in cardiac surgical patients undergoing cardiopulmonary bypass between 2018 to 2021 who received sugammadex versus those who did not.

SETTING

At a tertiary-care hospital in the Northshore of Chicago.

PARTICIPANTS

A total of 358 elective or urgent cardiac surgical patients who underwent cardiopulmonary bypass (by 1 cardiac surgeon) and were extubated within 24 hours of the end of surgery at Evanston Hospital in Evanston, IL, were included.

INTERVENTIONS

Data were examined in the following 2 groups of patients: those who were administered sugammadex and those who were not.

MEASUREMENTS AND MAIN RESULTS

After performing propensity matching for age, sex, body mass index, kidney or liver disease, the number of preoperative conditions (defined as the sum of the presence of the following medical conditions: diabetes, immunosuppressive disease, on home oxygen, on inhaled bronchodilator, or sleep apnea), number of patients who underwent elective or urgent surgery in each group, surgery time, cardiopulmonary bypass duration, number of intraoperative blood products, use of intraoperative midazolam and propofol, a statistically significant increase in the percentage of patients in the sugammadex group were extubated within 6 hours of the end of surgery versus those who did not receive sugammadex (96.67% v 81.33%, p = 0.0428). In addition, there was a statistically significant reduction in time to extubation (hours) (4.72 ± 2.92) v (3.57± 1.96 p = 0.0098) in the sugammadex group. All other outcomes did not meet statistical significance.

CONCLUSION

This retrospective study suggested that using sugammadex reversal in cardiac surgical patients undergoing cardiopulmonary bypass may result in more patients meeting the Society of Thoracic Surgery benchmark extubation criteria within 6 hours of the end of surgery.

Perioperative Optimization of the Cardiac Surgical Patient

Perioperative optimization of cardiac surgical patients is imperative to reduce complications, utilize health care resources efficiently, and improve patient recovery and quality of life. Standardized application of evidence-based best practices can lead to better outcomes. Although many practices should be applied universally to all patients, there are also opportunities along the surgical journey to identify patients who will benefit from additional interventions that will further ameliorate their recovery. Enhanced recovery programs aim to bundle several process elements in a standardized fashion to optimize outcomes after cardiac surgery. A foundational concept of enhanced recovery is attaining a better postsurgical end point for patients, in less time, through achievement and maintenance in their greatest possible physiologic, functional, and psychological state. Perioperative optimization is a broad topic, spanning multiple phases of care and involving a variety of medical specialties and nonphysician health care providers. In this review we highlight a variety of perioperative care topics, in which a comprehensive approach to patient care can lead to improved results for patients, providers, and the health care system. A particular focus on patient-centred care is included. Although existing evidence supports all of the elements reviewed, most require further improvements in implementation, as well as additional research, before their full potential and usefulness can be determined.

[The use of oscillatory respiratory therapy with positive expiratory pressure (PEP-therapy) to restore the functional state of the lungs in patients after cardiac surgery]

Postoperative pulmonary complications in cardiac surgery patients occur in 10-35% of cases, depending on differences in their definition, patient characteristics and type of surgical intervention, most of them are associated with ineffective coughing and evacuation of bronchial secretions.

OBJECTIVE

To determine the effectiveness of stimulating the evacuation of bronchial secretions with the help of oscillating PEP therapy carried out during the first three days.

MATERIAL AND METHODS

A randomized prospective study of 60 adult patients after elective cardiac surgery was performed (Clinical Trials.gov. protocol number NCT05159401). Oscillatory PEP-therapy was performed in 30 patients using Acapella DHGreen device (SmithMedicalASD, USA) 10-12 hours after tracheal extubation 3 times a day for 3 days after surgery. The control group (30 patients). The inclusion criteria: age over 18 years, spontaneous breathing after tracheal extubation, clear consciousness and productive contact with the patient, the ability to maintain adequate gas exchange on the low-flow oxygen inhalation, adequate analgesia (<2 points of VAS). Exclusion criteria: the need for re-intubation and mechanical ventilation, non-invasive mask ventilation, high-flow oxygen therapy, acute cerebrovascular accident, ongoing bleeding, cardiac insufficiency (inotropic index >10), shocks syndrome of various etiologies, the use of any extracorporeal support, any neuromuscular disorders, pneumothorax, hydro-or hemothorax. Before each session and 20 minutes after its end, when breathing air, blood oxygen saturation was recorded using a pulse oximeter (SpO2), the maximum inspiratory capacity (MIC) was measured using a Coach-2 incentive spirometer from SmithsMedical and spirometry with a portable ultrasonic spirometer Spiro Scout (Schiller, Switzerland). For the purposes of this work, the total index of the spirometry maximum inspiratory capacity (SMIC) was used - the sum of the respiratory volume and the reserve volume of inspiration in ml.

RESULTS

Difficulties in evacuation of sputum were noted in 90% of patients. Three-day sessions of oscillating PEP- therapy are accompanied by a significant improvement in the passage of sputum, as evidenced by a 3-fold increase in the number of patients with productive cough. The increase in MIC in the main group was 46.9% and 21.3%, respectively (p=0.042), and the number of patients with values greater than MICo. 1500 ml increased from 23.3% to 7.6% (p<0.001). The effectiveness of oscillatory PEP-therapy is confirmed by a 7-fold decrease in the frequency of radiological changes in the lungs at the end of sessions (p<0.001), while in the control group the frequency of their occurrence practically did not change and remained at a high level. The total number of patients with respiratory insufficiency (SpO2≤92%) decreased by 8.6 times after completion of all PEP- therapy sessions (p=0.001), however, without statistically significant difference with the control group.

CONCLUSIONS

Oscillatory PEP- therapy in cardiac surgery patients has a positive effect on sputum passage, ventilation parameters and oxygenating lung function. The procedure was well tolerated and there were no complications associated with it.