Long-term outcome and quality of life of patients requiring prolonged mechanical ventilation after cardiac surgery

Risk Factors and Predictors of Prolonged Mechanical Ventilation Following Cardiac Surgery: A Narrative Review

The subset of patients requiring prolonged mechanical ventilation is significantly high worldwide, making it an important topic of continuous and ongoing research. Over the years, various articles have shown that there may be predictors of prolonged ventilation that could be applied in healthcare to make it more patient-centered. The available literature suggests that authors have different definitions of "prolonged" ventilation. However, most critical care units embrace caution if a patient needs mechanical ventilation for more than 48 to 72 hours. The major benefits of mechanical ventilation are an overall decrease in the work of breathing and the facilitation of relatively easier pumping from an ailing heart. An elevated risk of prolonged ventilation after cardiac surgery exists in patients with higher classes of heart failure (as classified by the New York Heart Association (NYHA) or Canadian Cardiovascular Society (CCS)), a pre-existing congenital or acquired cardiac abnormality, and patients with renal failure, to name a few. The impact on quality of life has also been widely studied; as mortality rates increase with factors like age and days dependent on ventilation. Patients undergoing prolonged ventilation constitute an administrative challenge for critical care units, highlighting how multiple patients in this bracket can overwhelm the healthcare system. The use of prediction models in this context can aid healthcare delivery tremendously. Using different predictors, we can craft tailor-made treatment options and achieve the goal of more ventilator-free days per patient.

Development and validation of a clinical prediction model for early ventilator weaning in post-cardiac surgery

Background

Weaning patients from mechanical ventilation is a critical clinical challenge post cardiac surgery. The effective liberation of patients from the ventilator significantly improves their recovery and survival rates. This study aimed to develop and validate a clinical prediction model to evaluate the likelihood of successful extubation in post-cardiac surgery patients.

Method

A predictive nomogram was constructed for extubation success in individual patients, and receiver operating characteristic (ROC) and calibration curves were generated to assess its predictive capability. The superior performance of the model was confirmed using Delong's test in the ROC analysis. A decision curve analysis (DCA) was conducted to evaluate the clinical utility of the nomogram.

Results

Among 270 adults included in our study, 107 (28.84%) experienced delayed extubation. A predictive nomogram system was derived based on five identified risk factors, including the proportion of male patients, EuroSCORE II, operation time, pump time, bleeding during operation, and brain natriuretic peptide (BNP) level. Based on the predictive system, five independent predictors were used to construct a full nomogram. The area under the curve values of the nomogram were 0.880 and 0.753 for the training and validation cohorts, respectively. The DCA and clinical impact curves showed good clinical utility of this model.

Conclusion

Delayed extubation and weaning failure, common and potentially hazardous complications following cardiac surgery, vary in timing based on factors such as sex, EuroSCORE II, pump duration, bleeding, and postoperative BNP reduction. The nomogram developed and validated in this study can accurately predict when extubation should occur in these patients. This tool is vital for assessing risks on an individual basis and making well-informed clinical decisions.

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).

Difficult Respiratory Weaning after Cardiac Surgery: A Narrative Review

Respiratory weaning after cardiac surgery can be difficult or prolonged in up to 22.7% of patients. The inability to wean from a ventilator within the first 48 h after surgery is related to increased short- and long-term morbidity and mortality. Risk factors are mainly non-modifiable and include preoperative renal failure, New York Heart Association, and Canadian Cardiac Society classes as well as surgery and cardio-pulmonary bypass time. The positive effects of pressure ventilation on the cardiovascular system progressively fade during the progression of weaning, possibly leading to pulmonary oedema and failure of spontaneous breathing trials. To prevent this scenario, some parameters such as pulmonary artery occlusion pressure, echography-assessed diastolic function, brain-derived natriuretic peptide, and extravascular lung water can be monitored during weaning to early detect hemodynamic decompensation. Tracheostomy is considered for patients with difficult and prolonged weaning. In such cases, optimal patient selection, timing, and technique may be important to try to reduce morbidity and mortality in this high-risk population.

Machine learning algorithms for predicting mortality after coronary artery bypass grafting

Background

As the era of big data analytics unfolds, machine learning (ML) might be a promising tool for predicting clinical outcomes. This study aimed to evaluate the predictive ability of ML models for estimating mortality after coronary artery bypass grafting (CABG).

Materials and methods

Various baseline and follow-up features were obtained from the CABG data registry, established in 2005 at Tehran Heart Center. After selecting key variables using the random forest method, prediction models were developed using: Logistic Regression (LR), Support Vector Machine (SVM), Naïve Bayes (NB), K-Nearest Neighbors (KNN), Extreme Gradient Boosting (XGBoost), and Random Forest (RF) algorithms. Area Under the Curve (AUC) and other indices were used to assess the performance.

Results

A total of 16,850 patients with isolated CABG (mean age: 67.34 ± 9.67 years) were included. Among them, 16,620 had one-year follow-up, from which 468 died. Eleven features were chosen to train the models. Total ventilation hours and left ventricular ejection fraction were by far the most predictive factors of mortality. All the models had AUC > 0.7 (acceptable performance) for 1-year mortality. Nonetheless, LR (AUC = 0.811) and XGBoost (AUC = 0.792) outperformed NB (AUC = 0.783), RF (AUC = 0.783), SVM (AUC = 0.738), and KNN (AUC = 0.715). The trend was similar for two-to-five-year mortality, with LR demonstrating the highest predictive ability.

Conclusion

Various ML models showed acceptable performance for estimating CABG mortality, with LR illustrating the highest prediction performance. These models can help clinicians make decisions according to the risk of mortality in patients undergoing CABG.

Evaluating Quality in Adult Cardiac Surgery

National and institutional quality initiatives provide benchmarks for evaluating the effectiveness of medical care. However, the dramatic growth in the number and type of medical and organizational quality-improvement standards creates a challenge to identify and understand those that most accurately determine quality in cardiac surgery. It is important that surgeons have knowledge and insight into valid, useful indicators for comparison and improvement. We therefore reviewed the medical literature and have identified improvement initiatives focused on cardiac surgery. We discuss the benefits and drawbacks of existing methodologies, such as comprehensive regional and national databases that aid self-evaluation and feedback, volume-based standards as structural indicators, process measurements arising from evidence-based research, and risk-adjusted outcomes. In addition, we discuss the potential of newer methods, such as patient-reported outcomes and composite measurements that combine data from multiple sources.

Mining heterogeneous clinical notes by multi-modal latent topic model

Latent knowledge can be extracted from the electronic notes that are recorded during patient encounters with the health system. Using these clinical notes to decipher a patient’s underlying comorbidites, symptom burdens, and treatment courses is an ongoing challenge. Latent topic model as an efficient Bayesian method can be used to model each patient’s clinical notes as “documents” and the words in the notes as “tokens”. However, standard latent topic models assume that all of the notes follow the same topic distribution, regardless of the type of note or the domain expertise of the author (such as doctors or nurses). We propose a novel application of latent topic modeling, using multi-note topic model (MNTM) to jointly infer distinct topic distributions of notes of different types. We applied our model to clinical notes from the MIMIC-III dataset to infer distinct topic distributions over the physician and nursing note types. Based on manual assessments made by clinicians, we observed a significant improvement in topic interpretability using MNTM modeling over the baseline single-note topic models that ignore the note types. Moreover, our MNTM model led to a significantly higher prediction accuracy for prolonged mechanical ventilation and mortality using only the first 48 hours of patient data. By correlating the patients’ topic mixture with hospital mortality and prolonged mechanical ventilation, we identified several diagnostic topics that are associated with poor outcomes. Because of its elegant and intuitive formation, we envision a broad application of our approach in mining multi-modality text-based healthcare information that goes beyond clinical notes. Code available at https://github.com/li-lab-mcgill/heterogeneous_ehr.

Risk factors for and outcomes of prolonged mechanical ventilation in patients received DeBakey type I aortic dissection repairment

Background

This study aimed to identify risk factors for prolonged mechanical ventilation (PMV) and its association with disease prognosis following acute DeBakey type I aortic dissection surgery.

Methods

A total of 582 patients who received emergency surgery for acute DeBakey type I aortic dissection from 2014 to 2018 were enrolled in this study. Mechanical ventilation period after surgery longer than 48 hours was defined as postoperative PMV. Multiple logistic regression analysis was used to identify risk factors for PMV. This study also compared short- and long-term outcomes in patients who developed PMV with patients who did not develop this complication. To identify and compare long-term cumulative survival rate, Kaplan-Meier survival curve was plotted.

Results

Among all enrolled patients, 259 (44.5%) received PMV treatment. Our data suggested that the length of intensive care unit and hospital stay were longer for patients who received PMV treatment. Thirty-day mortality was also higher in patients with PMV than in patients without PMV. Elevated leukocyte count and increased serum cystatin C level upon admission, lower preoperative platelet count and longer cardiopulmonary bypass (CPB) duration were identified as risk factors for PMV. Interestingly, our data suggested that there was no significant difference of survival rate between patients with or without PMV history.

Conclusions

PMV after DeBakey type I aortic dissection repair surgery was a common complication and associated with increased short-term mortality rate but did not affect long-term mortality rate. Elevated preoperative leukocyte count, increased preoperative serum cystatin C level, lower preoperative platelet count and longer CPB duration were risk factors for PMV.

Low hematocrit levels: a risk factor for long-term outcomes in patients requiring prolonged mechanical ventilation after cardiovascular surgery. A retrospective study

While low-risk patients who undergo elective surgery can tolerate low hematocrit levels, the benefits of higher hematocrit levels might outweigh the risk of transfusion in high-risk patients. Therefore, this study aimed to evaluate the effects of perioperative hematocrit levels on mortality in patients requiring prolonged mechanical ventilation (PMV) after a cardiovascular surgery. This single-center retrospective cohort study was conducted on 172 patients who underwent cardiovascular surgery with cardiopulmonary bypass or off-pump coronary artery bypass grafting and required PMV for ≥72 hours in the intensive care unit (ICU) from 2008 to 2012 at the Yokohama City University Medical Center in Yokohama, Japan. Patients were classified according to hematocrit levels on ICU admission: high (≥30%) and low (<30%) groups. Of 172 patients, 86 were included to each of the low-hematocrit and high-hematocrit groups, with median hematocrit levels (first to third quartiles) of 27.4% (25.4%–28.7%) and 33.0% (31.3%–35.5%), respectively. The difference in survival rates was significant between the two groups using the log-rank test (HR 0.55, 95% CI 0.32 to 0.95, p=0.033). Cox regression analysis revealed that ≥30% increase in hematocrit levels on ICU admission was significantly associated with decreased long-term mortality (HR 0.40, 95% CI 0.20 to 0.80, p=0.0095). Lower hematocrit levels on ICU admission was a risk factor for increased long-term mortality, and higher hematocrit levels might outweigh the risk of transfusion in patients requiring PMV after a cardiovascular surgery.

In-hospital and mid-term outcomes in patients reoperated on due to bleeding following coronary artery surgery (from the KROK Registry)

OBJECTIVES

Surgical re-exploration due to postoperative bleeding that follows coronary artery surgery is associated with significant morbidity and mortality. The aim of this study was to assess a relationship between re-exploration, major postoperative complications, in-hospital mortality and mid-term outcomes in patients following coronary surgery, on the basis of nationwide registry data.

METHODS

We identified all consecutive patients enrolled in Polish National Registry of Cardiac Surgical Procedures (KROK Registry) who underwent isolated coronary surgery between January 2012 and December 2014. Preoperative data, major postoperative complications, hospital mortality and mid-term all-cause mortality were, respectively, analysed. Comparisons were performed in all patients, low-risk patients (EuroSCORE II < 2%, males, aged 60-70 years) and propensity-matched patients. The starting point for follow-up was the date of hospital discharge.

RESULTS

Among 41 353 analysed patients, 1406 (3.4%) underwent re-exploration. Reoperated patients had more comorbidities, more frequent major postoperative complications, higher in-hospital mortality (13.2% vs 1.8%, P < 0.001) and higher mid-term mortality in survivors (P < 0.001). In the low-risk population, 3.0% of patients underwent re-exploration. Reoperated low-risk patients and propensity-matched patients also had more frequent major postoperative complications and higher in-hospital mortality, but mid-term mortality in survivors was similar. In a multivariable analysis, re-exploration was an independent predictor of death and all major postoperative complications.

CONCLUSIONS

Surgical re-exploration due to postoperative bleeding following coronary artery surgery carries a high risk of perioperative mortality and is linked to major postoperative complications. Among patients who survive to hospital discharge, mid-term mortality is associated primarily with preoperative comorbidities.

Prolonged mechanical ventilation after left ventricular assist device implantation: risk factors and clinical implications

Aims

Unsuccessful weaning from ventilator after major cardiovascular procedures has been shown to be associated with increased post‐operative morbidity and mortality. Our study aimed to identify predictors and clinical implications of prolonged mechanical ventilation (PMV) after left ventricular assist device (LVAD) implantation.

Methods and results

We analysed the data of patients receiving a continuous‐flow LVAD in our centre from December 2010 to September 2017. PMV was defined by a duration of invasive ventilation of >7 days after LVAD implantation. Multivariable logistic regression analysis was performed for predictors of PMV. Survival was estimated by the Kaplan–Meier method. During the study period, 156 patients received a continuous‐flow LVAD in our centre. Seventeen patients were excluded due to early death (<7 days), and 139 patients were enrolled in the study (mean age: 58 years; male: 84%). The median duration of mechanical ventilation post‐operatively was 94 h (range: 5 to 4192 h). PMV was observed in 43% of patients. Patients on PMV were characterized by a more severe disease state at baseline, compared with the group of early extubation, as reflected by their Interagency Registry for Mechanically Assisted Circulatory Support level (Level 1–3: 72 vs. 49%, P = 0.008). Patients on PMV exhibited higher pulmonary wedge pressures (25 vs. 21 mmHg, P = 0.04), lower estimated glomerular filtration rate (53 vs. 60 mL/min/1.73 m², P = 0.02), lower haemoglobin (10.6 vs. 11.6 g/dL, P = 0.02), and lower platelet counts (189 vs. 240/nL, P = 0.02). Previous sternotomy was more frequent in the PMV group (32 vs. 13%, P = 0.006). Higher rates of preoperative circulatory support (30 vs. 11.4%, P = 0.006), dialysis (31.7 vs. 10.1%, P = 0.001), and invasive ventilation (35 vs. 7.6%, P < 0.001) were reported for the PMV group. Logistic regression analysis revealed that estimated glomerular filtration rate [odds ratio (OR) 0.977, confidence interval (CI) 0.955–0.999, P = 0.038], platelet count (OR 0.994, CI 0.989–0.998, P = 0.008), and previous sternotomy (OR 5.079, CI 1.672–15.427, P = 0.004) were independent predictors of PMV. PMV was accompanied by longer intensive care unit (24 vs. 4 days, P < 0.001) and hospital stay (47 vs. 32 days, P = 0.003). Survival analysis revealed a profound increase in mortality at 180‐day post‐implantation in the PMV group (62 vs. 10%, log‐rank: P < 0.001).

Conclusions

Prolonged mechanical ventilation affects nearly half of patients after LVAD implantation. Previous sternotomy, renal function, and platelet counts are associated with increased risk for PMV. PMV is accompanied by decreased survival at 180‐day post‐implantation and longer hospitalizations.

Ministernotomy or sternotomy in isolated aortic valve replacement? Early results

Introduction

Aortic valve replacement (AVR) is the gold standard in treating symptomatic aortic valve defects. To improve the healing process and limit the trauma, the minimally invasive approach was introduced.

Aim

To compare the peri- and post-operative results of aortic valve replacement performed via conventional full sternotomy (con-AVR) and of AVR performed via partial upper sternotomy (mini-AVR).

Material and methods

The total study population was divided into 2 demographically homogeneous groups: mini-AVR (n = 74) and con-AVR (n = 76). There were no statistically significant differences in preoperative echocardiography.

Results

Aortic cross-clamp time and cardiopulmonary bypass time were significantly longer in the mini-AVR group. Shorter mechanical ventilation time, hospital stay and lower postoperative drainage were observed in the mini-AVR group (p < 0.05). Biological prostheses were more frequently implanted in the mini-AVR group (p < 0.05). Patients from the mini-AVR group reported less postoperative pain. No significant differences were found in the diameter of the implanted aortic prosthesis, the amount of inotropic agents and painkillers, postoperative left ventricular ejection fraction (LVEF), medium and maximum transvalvular gradient or the number of transfused blood units. There were no differences in the frequency of postoperative complications such as mortality, stroke, atrial fibrillation, renal failure, wound infection, sternal instability, or the need for rethoracotomy.

Conclusions

Ministernotomy for AVR is a safe method and does not increase morbidity and mortality. It significantly reduces post-operative blood loss and shortens hospital stay. Ministernotomy can be successfully used as an alternative method to sternotomy.

Measuring the quality of perioperative care in cardiac surgery

Quality of care is of increasing importance in health and surgical care. In order to maintain and improve quality, we must be able to measure it and identify variation. In this narrative review, we aim to identify measures used in the assessment of quality of care in cardiac surgery and to evaluate their utility. The electronic databases Pubmed/MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), Cochrane Database of Systematic Reviews, and CINAHL were searched for original published studies using the terms 'cardiac surgery' and 'quality or outcome or process or structure' as either keywords in the title or text or MeSH terms. Secondary searches and identification of references from original articles were carried out. We found a total of 54 original articles evaluating measurements of quality. While structure, process, and outcome indicators remain the mainstay of quality measurement, new and innovative methods of risk assessment have improved reliability and discrimination. Continuous assessment provides a promising method of both maintaining and improving quality of care. Future studies should focus on long-term and patient-centred outcomes, such as quality-of-life measures.

Impact of Intubation Time on Survival following Coronary Artery Bypass Grafting: Insights from the Surgical Treatment for Ischemic Heart Failure (STICH) Trial

OBJECTIVE

The authors aimed to assess determinants of intubation time and evaluate its impact on 30-day and 1-year postoperative survival in Surgical Treatment for Ischemic Heart Failure (STICH) trial patients.

DESIGN, SETTING, PARTICIPANTS, AND INTERVENTIONS

A multivariable Cox proportional hazards model was used among the 1,446 surgical patients from the STICH trial who survived 36 hours after operation, in order to identify perioperative factors associated with 30-day and 1-year postoperative mortality. A multivariable logistic regression model was used to determine risk factors associated with intubation time.

MEASUREMENTS AND MAIN RESULTS

At 36 hours post-operation, 1,298 (out of 1,446) were extubated and 148 (10.2%) still intubated. Median postoperative intubation time was 11.4 hours. Among patients surviving 36 hours, a multivariable model was developed to predict 30-day (c-index = 0.88) and 1-year (c-index = 0.78) mortality. Intubation time was the strongest independent predictor of 30-day (hazard ratio [HR] 5.50) and 1-year mortality (HR 3.69). Predictors of intubation time >36 hours included mitral valve procedure, New York Heart Association class, left ventricular systolic volume index, creatinine, previous coronary artery bypass grafting (CABG), and age. Results were similar in patients surviving 24 hours post-operation, where intubation time was also the strongest predictor of 30-day (HR 4.18, c-index 0.87) and 1-year (HR 2.81, c-index 0.78) mortality.

CONCLUSIONS

Intubation time is the strongest predictor of 30-day and 1-year mortality among patients with ischemic heart failure undergoing CABG. Combining intubation time with other mortality risk factors may allow the identification of patients at the highest risk for whom the development of specific strategies may improve outcomes.

Intensive Care Unit Stay of More than 14 Days after Cardiac Surgery is Associated with Non-cardiac Organ Failure

Some studies have shown an association between a prolonged intensive care unit (ICU) stay and risk factors such as mediastinal re-exploration, advanced age, low ejection fraction, lung disease and organ failure. The aim of this retrospective study was first to evaluate peri-operative risk factors ( n = 2683) and secondly to evaluate long-term survival ( n = 2563) in cardiac surgery patients with an ICU stay > 14 days. Long-term survival was assessed in an observational 3-year follow-up study. An ICU stay of > 14 days was associated independently with respiratory failure and dialysis-dependent acute renal failure, and with a significantly lower survival rate. Since an ICU stay is associated with a higher hospital and long-term mortality, measures should be taken throughout the entire hospital stay to identify and reduce the risk of organ failure.

Postoperative Noninvasive Ventilation Following Cardiothoracic Surgery

Postoperative pulmonary complications following cardiac and thoracic surgery are common and associated with significant morbidity and mortality. Noninvasive ventilation has emerged as a successful and well-validated strategy to treat various acute medical conditions. More recently, noninvasive ventilation has been studied in selective surgical patient populations with the goal of preventing postoperative complications and treating acute respiratory failure. In this clinical review, we will briefly examine the incidence of pulmonary complications following cardiothoracic surgery and the physiology and mechanics of acute respiratory failure and noninvasive ventilation. We then present a systematic review of the indications, patient selection, and current literature investigating the specific use of noninvasive ventilation in this population.

Inclusion of 'ICU-Day' in a Logistic Scoring System Improves Mortality Prediction in Cardiac Surgery

Background

Prolonged intensive care unit (ICU) stay is a predictor of mortality. The length of ICU stay has never been considered as a variable in an additive scoring system. How could this variable be integrated into a scoring system? Does this integration improve mortality prediction?

Material/Methods

The ‘modified CArdiac SUrgery Score’ (CASUS) was generated by implementing the length of stay as a new variable to the ‘additive CASUS’. The ‘logistic CASUS’ already considers this variable. We defined outcome as ICU mortality and statistically compared the three CASUS models. Discrimination, comparison of receiver operating characteristic curves (DeLong’s method), and calibration (observed/expected ratio) were analyzed on days 1–13.

Results

Between 2007 and 2010, we included 5207 cardiac surgery patients in this prospective study. The mean age was 67.2±10.9 years. The mean length of ICU stay was 4.6±7.0 days and ICU mortality was 5.9%. All scores had good discrimination, with a mean area under the curve of 0.883 for the additive and modified, and 0.895 for the ‘logistic CASUS’. DeLong analysis showed superiority in favor of the logistic model as from day 5. The calibration of the logistic model was good. We identified overestimation (days 1–5) and accurate (days 6–9) calibration for the additive and ‘modified CASUS’. The ‘modified CASUS’ remained accurate but the ‘additive CASUS’ tended to underestimate the risk of mortality (days 10–13).

Conclusions

The integration of length of ICU stay as a variable improves mortality prediction significantly. An ‘ICU-day’ variable should be included into a logistic but not an additive model.

Analysis of Complaints from Patients During Mechanical Ventilation After Cardiac Surgery: A Retrospective Study

OBJECTIVES

This study analyzed major complaints from patients during mechanical ventilation after cardiac surgery and identified the most common complaints to reduce adverse psychologic responses.

DESIGN

Retrospective.

SETTING

A single tertiary university hospital.

PARTICIPANTS

Patients with heart disease who were on mechanical ventilation after cardiac surgery (N = 800).

INTERVENTIONS

The major complaints of the patients during mechanical ventilation after cardiac surgery were analyzed.

MEASUREMENTS AND MAIN RESULTS

Patients' comfort was evaluated using a visual analog scale, and the factors affecting comfort were analyzed. The average visual analog scale score in all patients was 5.8±2.0, and most patients presented moderate discomfort. The factors affecting comfort included dry mouth, thirst, tracheal intubation, aspiration of sputum, communication barriers, limited mobility, fear/anxiety, patient-ventilator dyssynchrony, and poor environmental conditions. Of these factors, 8 were independent predictors of the visual analog scale score. Patients considered mechanical ventilation to be the worst part of their hospitalization.

CONCLUSIONS

The study identified 8 independent factors causing discomfort in patients during mechanical ventilation after cardiac surgery. Clinicians should take appropriate measures and implement nursing interventions to reduce suffering, physical and psychologic trauma, and adverse psychologic responses and to promote recovery.

Predictors of prolonged mechanical ventilation after open heart surgery

Introduction: Due to the importance of prolonged mechanical ventilation (PMV) as a postoperative complication, predicting "high-risk" patients by identifying predisposing risk factors is of important issue. The present study was aimed to identify perioperative variables associated with PMV in patients undergoing open heart surgery.

Methods: A total of 743 consecutive patients, American Society of Anesthesiologists (ASA) physical status class III, who were scheduled to undergo open heart surgery using cardiopulmonary bypass were included in this observational study. Perioperative variables were compared between the patients with and without PMV, as defined by an extubation time of >48 h.

Results: PMV occurred in 45 (6.1%) patients. On univariate analysis, pre-operative variables; including gender, history of chronic obstructive pulmonary disease (COPD); chronic kidney disease and endocarditis, intra-operative variables; including type of surgery, operation time, pump time, transfusion in operating room and postoperative variables; including bleeding and inotrope-dependency were significantly different between patients with and without PMV (all P<0.001, except for COPD and transfusion in operating room; P=0.004 and P=0.017, respectively).

Conclusion: Our findings reinforce that risk stratification for predicting delayed extubation should be an important aspect of preoperative clinical evaluation in all anesthesiology settings.

Recent advances in mechanical ventilation in patients without acute respiratory distress syndrome

While being an essential part of general anesthesia for surgery and at times even a life-saving intervention in critically ill patients, mechanical ventilation has a strong potential to cause harm. Certain ventilation strategies could prevent, at least to some extent, the injury caused by this intervention. One essential element of so-called ‘lung-protective’ ventilation is the use of lower tidal volumes. It is uncertain whether higher levels of positive end-expiratory pressures have lung-protective properties as well. There are indications that too high oxygen fractions of inspired air, or too high blood oxygen targets, are harmful. Circumstantial evidence further suggests that spontaneous modes of ventilation are to be preferred over controlled ventilation to prevent harm to respiratory muscle. Finally, the use of restrictive sedation strategies in critically ill patients indirectly prevents ventilation-induced injury, as daily spontaneous awakening and breathing trials and bolus instead of continuous sedation are associated with shorter duration of ventilation and shorten the exposure to the injurious effects of ventilation.

Soluble isoform of the receptor for advanced glycation end products as a biomarker for postoperative respiratory failure after cardiac surgery

Purpose

Postoperative respiratory failure is a major problem which can prolong the stay in the intensive care unit in patients undergoing cardiac surgery. We measured the serum levels of the soluble isoform of the receptor for advanced glycation end products (sRAGE), and we studied its association with postoperative respiratory failure.

Methods

Eighty-seven patients undergoing elective cardiac surgery were enrolled in this multicenter observational study in three university hospitals. Serum biomarker levels were measured perioperatively, and clinical data were collected for 7 days postoperatively. The duration of mechanical ventilation was studied for 28 days.

Results

Serum levels of sRAGE elevated immediately after surgery (median, 1751 pg/mL; interquartile range (IQR) 1080–3034 pg/mL) compared with the level after anesthetic induction (median, 884 pg/mL; IQR, 568–1462 pg/mL). Postoperative sRAGE levels in patients undergoing off-pump coronary artery bypass grafting (median, 1193 pg/mL; IQR 737–1869 pg/mL) were significantly lower than in patients undergoing aortic surgery (median, 1883 pg/mL; IQR, 1406–4456 pg/mL; p = 0.0024) and valve surgery (median, 2302 pg/mL; IQR, 1447–3585 pg/mL; p = 0.0005), and postoperative sRAGE correlated moderately with duration of cardiopulmonary bypass (r_s = 0.44, p<0.0001). Receiver operating characteristic curve analysis demonstrated that postoperative sRAGE had a predictive performance with area under the curve of 0.81 (95% confidence interval 0.71–0.88) for postoperative respiratory failure, defined as prolonged mechanical ventilation >3 days. The optimum cutoff value for prediction of respiratory failure was 3656 pg/mL, with sensitivity and specificity of 62% and 91%, respectively.

Conclusions

Serum sRAGE levels elevated immediately after cardiac surgery, and the range of elevation was associated with the morbidity of postoperative respiratory failure. Early postoperative sRAGE levels appear to be linked to cardiopulmonary bypass, and may have predictive performance for postoperative respiratory failure; however, large-scale validation studies are needed.

Impact of major non-cardiac complications on outcome following cardiac surgery procedures: logistic regression analysis in a very recent patient cohort

OBJECTIVES

In this study, we sought to analyse the incidence of major non-cardiac complications and their impact on survival following cardiac surgery procedures in a contemporary patient cohort. We further determined independent predictors of perioperative mortality and created a logistic regression model for prediction of outcome after the occurrence of these complications.

METHODS

Prospectively collected data of 5318 consecutive adult patients (mean age 68.9±11.0 years; 29.3% [n=1559] female) undergoing cardiac surgery from January 2009 to May 2012 were retrospectively analysed. Outcome measures were six major non-cardiac complications including respiratory failure, dialysis-dependent renal failure, deep sternal wound infection (DSWI), cerebrovascular accident (CVA), gastrointestinal complications (GIC) and sepsis and their impact on perioperative mortality and hospital length of stay using multivariate regression models. The discriminatory power was evaluated by calculating the area under the receiver operating characteristic curves (C statistic).

RESULTS

A total of 1321 complications were observed in 846 (15.9%) patients: respiratory failure (n=432; 8.1%), dialysis-dependent renal failure (n=295; 5.5%), GIC (n=154; 2.9%), CVA (n=151; 2.8%), DSWI (n=146; 2.7%) and sepsis (n=143; 2.7%). Perioperative mortality was 17.0% in patients with at least one major non-cardiac complication and correlated with the number of complications (single, 9.7%; n=53/549; double, 24.0%; n=44/183; ≥3, 41.2%; n=47/114, P<0.001). Six preoperative and four postoperative independent predictors of operative mortality were identified (age (odds ratio [OR] 1.8; 95% confidence interval [CI] 1.3-2.4), peripheral vascular disease (OR 2.6; 95% CI 1.6-4.2), pulmonary hypertension (OR 2.7; 95% CI 1.5-4.9), atrial fibrillation (OR 1.5; 95% CI 1.0-2.3), emergency (OR 5.0; 95% CI 3.4-7.2), other procedures than CABG (OR 1.5; 95% CI 1.0-2.1), postoperative dialysis (OR 4.0; 95% CI 2.6-6.1), sepsis (OR 3.4; 95% CI 2.0-5.6), respiratory failure (OR 3.2; 95% CI 2.2-4.9), GIC (OR 3.2; 95% CI 1.9-5.3)) and included in the logistic model, which accurately predicted outcome (C statistic, 0.892; 95% CI 0.868-0.916). Length of hospital stay was significantly increased according to the number of complications (single: median 15 (IQR 10-24) days, double: 16 (IQR 8-28) days, ≥3: 20 (IQR 13-39) days, P<0.001).

CONCLUSIONS

With a worsening in the risk profile of patients undergoing cardiac surgery, an increasing number of patients develop major complications leading to increased length of stay and mortality, which is correlated to the number and severity of these complications. Our predictive model based on preoperative and postoperative variables allowed us to determine with accuracy the perioperative mortality in critically ill patients after cardiac surgery.

Prolonged ventilation post cardiac surgery--tips and pitfalls of the prediction game

Background

Few available models aim to identify patients at risk of prolonged ventilation after cardiac surgery. We compared prediction models developed in ICU in two adjacent periods of time, when significant changes were observed both in population characteristics and the perioperative management.

Methods

We performed a retrospective review of two cohorts of patients in our department in two subsequent time periods (July 2007 - December 2008, n = 2165; January 2009 - July 2010, n = 2192). The study was approved by the Institutional Ethics Committee and the individual patient consent was not required. Patients were divided with regard to ventilation time of more or less than 48 hours. Preoperative and procedure-related variables for prolonged ventilation were identified and multivariate logistic regression analysis was performed separately for each cohort.

Results

Most recent patients were older, with more co-morbidities, more frequently undergoing off-pump surgery. At the beginning of 2009 we also changed the technique of postoperative ventilation. Percentage of patients with prolonged ventilation decreased from 5.7% to 2.4% (p < 0.0001).Preoperative and procedure-related variables for prolonged ventilation were identified. Prediction models for prolonged ventilation were different for each cohort. Most recent significant predictors were: aortic aneurysm surgery (OR 12.9), emergency surgery (OR 5.3), combined procedures (OR 5.1), valve procedures (OR 3.2), preoperative renal dysfunction (OR 2.9) and preoperative stroke or TIA (OR 2.8).

Conclusions

Prediction models for postoperative ventilation should be regularly updated, particularly when major changes are noted in patients' demographics and surgical or anaesthetic technique.

Bacterial resistance and mortality in an intensive care unit

The goal was to identify risk factors for healthcare-associated infections by resistant microorganisms and patient mortality in an Intensive Care Unit. A prospective and descriptive epidemiological research was conducted from 2005 till 2008, involving 2300 patients. Descriptive statistics, bivariate and multivariate logistic regression analysis were used. In bivariate analysis, infection caused by resistant microorganism was significantly associated to patients with community-acquired infection (p=0.03; OR=1.79) and colonization by resistant microorganism (p<0.01; OR=14.22). In multivariate analysis, clinical severity (p=0.03; OR=0.25) and colonization by resistant microorganism (p<0.01; OR=21.73) were significant. Mortality was associated to the following risk factors: type of patient, average severity index, besides mechanical ventilation. The relation between resistant microorganisms and death shows the need to monitor adherence to infection control measures so as to improve care quality and mainly survival of critical patients.

Long-term survival after surgical critical illness: the impact of prolonged preceding organ support therapy

OBJECTIVE

To identify the prognostic importance of preceding invasive ventilation, renal replacement therapy, and catecholamine therapy for long-term survivors after surgical critical illness.

SUMMARY BACKGROUND DATA

Nothing is known about the effect of preceding intensive care unit (ICU)-related therapies on long-term outcome.

METHODS

We performed a retrospective analysis of prospectively collected data of an ICU patient cohort linked to a local database. Adult patients (n = 1462) admitted to a 12-bed ICU between 1993 and 2005, who had an ICU length of stay of more than 4 days, were followed up until the end of the second year after ICU admission. Hazard function was explored by Weibull modeling and likelihood ratio tests. Cox-type structured hazard regression models were used to analyze linear, nonlinear, or time-varying associations of therapeutic variables with 2-year survival time of a patient subgroup, which had survived the period of high hazard.

RESULTS

Hazard rate declined exponentially up to day 195 after ICU admission, and became constant thereafter. A total of 808 patients reached this stable stage of their disease forming the study population. Of these patients, 648 (80.2%) were still alive at the end of the second year after ICU admission. Underlying diseases were major determinants for long-term outcome. Long-term mortality was significantly associated with the acute extent of physiological derangement during ICU stay (maximum Apache II score), but was independent from the duration of preceding invasive organ support.

CONCLUSION

In surgical patients with a prolonged ICU length of stay, an exorbitant mortality exists for about half a year after ICU admission. Later on, life expectancy of surviving patients is largely determined by the underlying disease and, to a minor degree, by the acute extent of homeostatic disturbance during ICU stay. The duration of preceding invasive therapies does not limit long-term survival.

Risk factors for late extubation after coronary artery bypass grafting

OBJECTIVE

To evaluate the independent risk factors for late extubation after coronary artery bypass grafting (CABG).

METHODS

Preoperative, intraoperative, and postoperative characteristics of patients undergoing isolated CABG between June 2005 and June 2008 at the Tongji Hospital were retrospectively analyzed. Elapsed time between CABG and extubation of more than 8hours was defined as late extubation.

RESULTS

The incidence of late extubation after CABG was 69.23% (288/416). Through univariate and logistic regression analysis, the independent risk factors for late extubation after CABG were older age (odds ratio [OR]=4.804), duration of cardiopulmonary bypass (OR=2.426), perioperative use of intra-aortic balloon pump (OR=1.451), preoperative arterial oxygen partial pressure (OR=.204), and postoperative hemoglobin level (OR=.793).

CONCLUSION

Older age, prolonged cardiopulmonary bypass time, perioperative intra-aortic balloon pump requirement, low preoperative arterial oxygen partial pressure, and low postoperative hemoglobin level were identified as the 5 independent risk factors for late extubation after CABG.

Terminal withdrawal of mechanical ventilation at a long-term acute care hospital: comparison with a medical ICU

BACKGROUND

Failure to wean from prolonged mechanical ventilation (MV) is common in long-term acute care hospitals (LTACHs), but the process of terminal withdrawal of MV in LTACHs is not well described. We compared terminal withdrawal of MV at an LTACH with that in a medical ICU (MICU).

METHODS

A retrospective medical chart review was done of all patients undergoing terminal withdrawal of MV in an LTACH (n = 30) and in a MICU (n = 74) over a 2-year period.

RESULTS

The decision to withdraw MV was more likely initiated by patient or family in the LTACH and by medical staff in the MICU (p < 0.0001). Social workers, pastoral care, and hospital administration were more likely to participate in the withdrawal process at the LTACH compared with the MICU (p < 0.05). Time from initiation of MV to orders for do not resuscitate, comfort measures only, or withdrawal of MV was significantly greater in the LTACH (weeks) compared with the MICU (days) (p < 0.05). The dose of benzodiazepines given during the final 24 h of life was greater in the MICU as compared with the LTACH (p < 0.05). Narcotic and benzodiazepine use in the hour before or after withdrawal of MV did not differ between the two groups. COPD and pneumonia were the most common causes of death among patients undergoing withdrawal of MV at the LTACH, as opposed to septic shock in the MICU (p < 0.05).

CONCLUSIONS

Terminal withdrawal of MV in the LTACH differs from that in the MICU with regard to decision making, benzodiazepine use, and cause of death.

Effects of remifentanil and fentanyl on the cell-mediated immune response in patients undergoing elective coronary artery bypass graft surgery

This prospective randomized pilot study compared the influence of fentanyl-based versus remifentanil-based anaesthesia on cytokine responses and expression of the suppressor of cytokine signalling (SOCS)-3 gene following coronary artery bypass graft surgery. Forty patients were assigned to receive anaesthesia with either intravenous remifentanil (0.3 - 0.6 microg/kg per min; n = 20) or intravenous fentanyl (5 - 10 microg/kg per h; n = 20). Levels of interleukin (IL)-6, IL-10, tumour necrosis factor-alpha and interferon-gamma (IFN-gamma) and the expression of SOCS-3 were measured pre- and post-operatively. The data from 33 of the patients were analysed. The IFN-gamma/IL-10 ratio after concanavalin A stimulation in whole blood cells on post-operative day 1 and SOCS-3 gene expression on post-operative day 2 were significantly lower in the remifentanil group than in the fentanyl group. The time in the intensive care unit was also significantly lower in the remifentanil group. These findings suggest that remifentanil can attenuate the exaggerated inflammatory response that occurs after cardiac surgery with cardiopulmonary bypass. Further clinical trials are required to define the influence of choice of intra-operative opioid on post-operative outcome.

The association between early outcome, health-related quality of life, and survival following elective open-heart surgery

We investigated the impact of perioperative complications on patients' health-related quality of life (HRQL) and intermediate-term survival after cardiac surgery. Improved results for cardiac surgery are well demonstrated in low rates of operative mortality and morbidity. However, the association between perioperative morbid events, HRQL at 1 year, and survival is unclear. We performed a prospective study among 836 elective cardiac surgery patients to assess the impact of perioperative outcomes on survival and HRQL at 1 year. Health-related quality of life was generated using the 20-item short-form questionnaire. Kaplan-Meier and life-table estimates were used to examine the relationship of HRQL at 1-year and intermediate-term survival. All HRQL domains were statistically improved at 1 year, with the highest gains in general health perception (+19.4%) and the least gains in social (+5.1%) and mental (+5.1%) domains. Patients experiencing 1 or more perioperative complication or increased length of stay reported similar HRQL scores as patients with no complications. Patients with negative changes in social (94.5% vs 99.2%, P < .001) and general health perception (99.4% vs 95.5%, P < .001) domains showed a reduced survival compared with patients with positive HRQL gains at 2 to 5 years after surgery. Perioperative complications had minimal or no effect on HRQL at 1 year after cardiac surgery.

Risk factors for prolonged mechanical ventilation following surgery for acute type a aortic dissection

BACKGROUND

The aim of this study was to identify predictors of prolonged mechanical ventilation (PMV) following surgery for acute type A aortic dissection (AAAD) and to assess the influence of this complication on clinical outcomes.

METHODS AND RESULTS

A total of 243 patients underwent emergency surgery for AAAD in the period of 1997-2006. Ten patients died within 48 h after surgery. The remaining 233 patients were divided into 2 groups according to the duration of mechanical ventilation; less than 48 h (group A: n=149) or 48 h or longer (group B; n=84). Multivariate analysis was used to identify predictors of PMV. Short and late outcomes were compared between groups. Multivariate analysis showed that shock (systolic BP <90 mmHg; p=0.007), postoperative renal dysfunction (creatinine >2.0 mg/dl; p=0.016), coronary artery bypass grafting (CABG) (p=0.017), and limb ischemia (p=0.044) were independent predictors of PMV. There was no significant difference in in-hospital mortality (group A, 2.7% vs group B, 3.6%) or 5-year survival (group A, 85.9% vs group B, 76.8%).

CONCLUSIONS

Shock, limb ischemia, CABG, and postoperative renal dysfunction increase the risk for PMV. Knowing the predictors of PMV should help optimize postoperative management of these patients.

Coronary artery bypass grafting is associated with excellent long-term survival and quality of life: a prospective cohort study

BACKGROUND

We investigated the long-term outcome of coronary artery bypass grafting both in terms of survival and quality of life.

METHODS

Ten-year postsurgery survival was collated on patients undergoing coronary artery bypass grafting from 1994 to 1996, and quality of life was assessed using EQ-5D and a quality-of-life thermometer. We analyzed data from 1,180 patients. Mean age was 61 years, and 79% had triple-vessel disease.

RESULTS

Thirty-day mortality was 3.3% (1.8% elective). Mean time to censorship for survivors was 9.9 years (range, 8.1 to 12.3 years). Ten-year survival was 66% across all patients, 70% for elective patients. Ten-year cardiac survival was 82%. Percutaneous intervention was required in 25 patients in the subsequent 10 years (2%), and only 4 required redo coronary artery bypass grafting (0.3%); 59% of patients reported no angina, and 88% of patients had grade II angina or better. Of 621 patients who were assessed for quality of life at 10 years, 530 (85%) had a quality of life within a 95% confidence interval of the score found in the general population with similar age. Poor quality of life was reported in 91 patients (14.7%). Significant predictors of poor long-term quality of life were current smoking, Canadian Cardiovascular Society grade III or IV, redo operation, female sex, diabetes, peripheral vascular disease, more than 2 days in intensive care, and chronic obstructive pulmonary disease. Twenty-five percent of patients with poor EQ-5D outcome had grade IV angina. Interestingly, age did not correlate with poor outcome, and administration of blood, arterial revascularization, left mainstem disease, or cross-clamp fibrillation had no impact on survival or outcome.

CONCLUSIONS

Coronary artery bypass grafting is associated with excellent 10-year survival and quality of life.

Acute and long-term survival in chronically critically ill surgical patients: a retrospective observational study

INTRODUCTION

Various cohort studies have shown that acute (short-term) mortality rates in unselected critically ill patients may have improved during the past 15 years. Whether these benefits also affect acute and long-term prognosis in chronically critically ill patients is unclear, as are determinants relevant to prognosis.

METHODS

We conducted a retrospective analysis of data collected from March 1993 to February 2005. A cohort of 390 consecutive surgical patients requiring intensive care therapy for more than 28 days was analyzed.

RESULTS

The intensive care unit (ICU) survival rate was 53.6%. Survival rates at one, three and five years were 61.8%, 44.7% and 37.0% among ICU survivors. After adjustment for relevant covariates, acute and long-term survival rates did not differ significantly between 1993 to 1999 and 1999 to 2005 intervals. Acute prognosis was determined by disease severity during ICU stay and by primary diagnosis. However, only the latter was independently associated with long-term prognosis. Advanced age was an independent prognostic determinant of poor short-term and long-term survival.

CONCLUSION

Acute and long-term prognosis in chronically critically ill surgical patients has remained unchanged throughout the past 12 years. After successful surgical intervention and intensive care, long-term outcome is reasonably good and is mainly determined by age and underlying disease.

Ventilatory dependency after cardiovascular surgery

OBJECTIVES

Ventilatory dependency is a widely recognized complication of cardiovascular surgery, often leading to tracheostomy. Some risk factors for its occurrence have been documented. Less well characterized are short- and long-term outcomes. Therefore, objectives were to identify risk factors for ventilatory dependency, assess its short- and long-term outcomes, and determine impact of tracheostomy.

METHODS

From January 1998 to September 2001, 12,777 patients underwent cardiovascular surgery and survived at least 72 hours. Of these patients, 704 (5.5%) developed ventilatory dependency (cumulative intubation >72 hours); 185 (26%) underwent tracheostomy. Preoperative, intraoperative, and intensive care unit admission data were used sequentially to understand predictors of ventilatory dependency. Outcomes were analyzed by time-related methods, and impact of tracheostomy was assessed using competing-risks analysis.

RESULTS

Hemodynamic status on intensive care unit admission (low cardiac output, vasopressor use, pulmonary hypertension; P < .0001) and early postoperative events (stroke, bacteremia; P < .0001) were more important than preoperative and intraoperative variables in predicting ventilatory dependency. Survival at 30 days, 1 year, and 5 years thereafter was 76%, 49%, and 33% and was strongly associated with favorable hemodynamic status. By 28 days, 24% of patients received tracheostomy; survival at 30 days and 2 years thereafter was 74% and 26%, considerably below anticipated survivals of 84% and 58%.

CONCLUSIONS

Improved operative and postoperative strategies to preserve myocardial function and restore hemodynamics should decrease the prevalence of ventilatory dependency. Unfortunately, preoperative models of ventilatory dependency are too insensitive for clinical use. Tracheostomy and its outcome are also poorly predicted, highlighting the complex interaction of events altering patients' conditions before and after tracheostomy.

Quality of life after heart valve surgery with prolonged intensive care

BACKGROUND

A small proportion of patients undergoing heart valve operations require prolonged intensive care after surgery. Little is known about the quality of life that such patients attain after hospital discharge.

METHODS

All consecutive patients who underwent primary heart valve surgery from 1998 to 2003 and required 8 days or more of treatment in an intensive care unit (ICU) were included (n = 225). At follow-up on August 31, 2004, 154 of these patients were alive. A cohort (n = 154) matched for sex, age, type of procedure, and week of operation, with an uncomplicated postoperative course (ICU stay of 2 days or less), served as the control group. All patients received the Medical Outcomes Study Short-Form 36, the Nottingham Health Profile, and the Hospital Depression and Anxiety scale to evaluate their quality of life.

RESULTS

Survival at 5 years in the total ICU group was 68% (154 of 225). According to SF-36, the ICU study cohort reported poorer physical health but equal mental health compared with controls. On the Nottingham Health Profile, the ICU group reported more problems in all domains except emotional reactions and sleep. There was no difference in anxiety or depression between the groups. The ICU patients were in more advanced New York Heart Association functional classes preoperatively and postoperatively. No patient in the ICU study cohort regretted undergoing the operation, and 80% experienced improvement after surgery.

CONCLUSIONS

This study showed reduced quality of life in terms of physical health and equal mental health in patients who required prolonged intensive care after heart valve surgery compared with controls without complications.

Three-year survival after four major post–cardiac operative complications*

OBJECTIVE

After cardiac surgery, major morbidities known to be primary contributors to perioperative mortality are cardiac failure, respiratory failure, renal failure, and the need for mediastinal exploration. The first aim of this study was to ascertain long-term survival in cardiac surgery patients with and without the occurrence of major morbidities to investigate if long-term survival was comparable. The second aim of this study was to evaluate the prevalences and risk factors related to the four major morbidities in this patient population.

DESIGN

Retrospective observational outcome study.

SETTING

Cardiothoracic intensive care unit at a university hospital.

PATIENTS

We included 2,683 of 3,253 consecutive cardiac surgery patients cared for in a uniform fashion.

METHODS AND MAIN RESULTS

Perioperative mortality was significantly increased by the occurrence of major morbidity. In-hospital mortality was 0.7% in the absence of major morbidity compared with 72% when all major morbidities occurred. Three-year mortality for the entire study population was 15%, whereas the 3-yr long-term survival was significantly less for patients with morbidities compared with those without. Various independent perioperative risk factors were found for perioperative major morbidity and mortality.

CONCLUSIONS

Successful acute treatment and measures to identify and reduce the risk of major morbidities are necessary to improve outcome. In addition, long-term follow-up and management of morbidities are necessary to possibly improve long-term survival.

Early continuous venovenous hemodialysis in dialysis-dependent patients after cardiac surgery: safety and efficacy

OBJECTIVES

The present study assessed the safety and efficacy of continuous venovenous hemodialysis (CVVHD) early after cardiac surgery.

DESIGN

Retrospective database and medical record review.

SETTING

University teaching hospital.

PARTICIPANTS

Forty-five dialysis-dependent patients who underwent cardiac surgery with cardiopulmonary bypass.

INTERVENTIONS

CVVHD was begun postoperatively after confirmation of hemostasis, irrespective of circulatory status. In the last 5 patients, the ratio of extravascular lung water (EVLW) to intrathoracic blood volume (ITBV) was measured using a single-indicator thermodilution catheter and compared with patients of normal renal function undergoing cardiac surgery.

MEASUREMENTS AND MAIN RESULTS

CVVHD was started at 4 hours after ICU admission. The maximum decrease in blood pressure within 60 minutes after initiation of CVVHD was 11 +/- 9 mmHg in the unstable hemodynamics group (defined as patients who required continuous intravenous adrenaline or intra-aortic balloon pump on admission to the ICU [n = 15]) and 7 +/- 8 mmHg in the stable hemodynamics group (n = 30, not significant). Circulatory status and oxygenation improved significantly 12 hours after CVVHD initiation in the unstable hemodynamics group. Blood volume from the chest tube did not increase after CVVHD. Early mortality (2.2%) was lower than that reported previously. The EVLW/ITBV ratio after ICU admission in dialysis-dependent patients was significantly higher than in patients with normal renal function.

CONCLUSIONS

Early CVVHD after cardiac surgery in dialysis-dependent patients was safe and effective. There was no associated increased postoperative bleeding or hemodynamic instability. Fluid removal improved respiratory status, particularly in patients requiring circulatory assistance, and overall early morality rates were lower that those previously published.

Prolonged Intensive Care Unit Stay in Cardiac Surgery: Risk Factors and Long-Term-Survival

BACKGROUND

Risk factors have been found for prolonged intensive care unit (ICU) stay in cardiac surgery patients in only a few studies; conflicting results have been described. The focus of this study was twofold: first, to evaluate preoperative, intraoperative, and postoperative risk factors for ICU stay greater than 3 days in a cardiac surgery patient population; second, to evaluate long-term survival in cardiac surgery patients with prolonged ICU stay.

METHODS

Records from 2,683 cardiac surgery patients were retrospectively evaluated. Univariate and multivariate analyses for risk factors were performed for an ICU stay greater than 3 days. Thereafter, 2,563 patients were enrolled in a follow-up study for an observational time of 3 years after surgery.

RESULTS

Mortality was dependent on renal, respiratory, and heart failure, as well as age, elevated APACHE II scores, and reexploration. Long-term survival analyses demonstrated a significantly lower survival in patients with longer ICU stay. However, the 6-month to 3-year long-term survival was comparable with survival in patients without prolonged ICU stay.

CONCLUSIONS

Because of the increasing acuity of patients needing cardiac surgery, it is important to identify those at risk for a prolonged ICU course. It is therefore of paramount interest to implement measures throughout their entire hospital stay that would maximize organ function to improve survival and resource utilization.

Duration of Dialysis Is a Significant Predictor of Prolonged Postoperative Mechanical Ventilation in Dialysis-Dependent Patients Undergoing Cardiac Surgery

Prolonged mechanical ventilation is reported to correlate with increased risk of mortality after cardiac surgery. We designed the present study to determine the preoperative and intraoperative risk factors that could predict postoperative prolonged mechanical ventilation in dialysis-dependent patients undergoing cardiac surgery with cardiopulmonary bypass. Forty-four dialysis-dependent patients were divided into two groups; patients of group E were tracheally extubated within 24 h after admission to the intensive care unit postoperatively (n = 19) and patients of group L (n = 25) required more than 24 h of mechanical ventilation. All patients received hemofiltration during cardiopulmonary bypass and continuous veno-venous hemodialysis postoperatively. A multiple logistic regression analysis showed that duration of dialysis (>10 yr) and duration of surgery (>8 h) were independent risk factors of prolonged mechanical ventilation (>24 h). On admission to the intensive care unit, Pao2/Fio2 of group L was significantly lower than that of group E (294 +/- 135 versus 415 +/- 99 mm Hg) and the circulatory status of group L was worse than that of group E. The median (interquartile range) duration of intensive care unit stay in group E was 3 (3.00) days, which was significantly shorter than that of group L (5 [2.75] days). It is possible that longer surgery increases the likelihood of cardiac dysfunction and poor oxygenation in patients with a long history of dialysis.

Risk factors for and economic implications of prolonged ventilation after cardiac surgery

OBJECTIVE

The study's objective was to identify predictors of prolonged ventilation and assess clinical and cost implications in patients undergoing cardiac surgery.

METHODS

Patients undergoing cardiac surgery were classified as (1) ventilated less than 96 hours or (2) ventilated 96 hours or more. Multivariate modeling was used to identify predictors of prolonged ventilation and to ascertain the impact of prolonged ventilation on in-hospital mortality and bed occupancy costs and 5-year survival.

RESULTS

A total of 7553 patients were studied; 197 (2.6%) had prolonged ventilation. Median ventilation times were 8 and 192 hours, and in-hospital mortality was 1.0% and 22.2% in the control and prolonged ventilation groups, respectively (P < .001). In-hospital mortality remained higher in the prolonged ventilation group after adjustment and when comparing propensity-matched patients (odds ratio 8.06; 95% confidence interval [CI] 4.27-15.2; P < .001 for propensity-matched groups). Independent predictors of prolonged ventilation were as follows: older age, New York Heart Association class, ejection fraction less than 50%, creatinine greater than 200 micromol/L, multiple valve replacements, aortic procedures, operative priority, reoperation for bleeding, inotropes, and preoperative intra-aortic balloon pump. Five-year survival was lower in the prolonged ventilation group (56.1% [95% CI 46.6%-64.6%] vs 88.8% [95% CI 87.9%-89.6%]) also after adjustment for imbalances and when comparing propensity-matched patients (hazard ratio 2.39; 95% CI 1.75-3.27; P < .001 for propensity-matched groups). Mean bed occupancy costs were 14,286 dollars (95% CI 12,731 dollars-15,690 dollars) and 2761 dollars (95% CI 2705 dollars-2814 dollars) in the prolonged ventilation and control groups, respectively (P < .001).

CONCLUSION

Prolonged ventilation is associated with high in-hospital mortality and costs, and poor 5-year survival. Identified predictors of prolonged ventilation might help to optimize the clinical management of these patients.