Logistic Risk Model for Prolonged Ventilation After Adult Cardiac Surgery

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.

The Effects of Different Doses of Sufentanil on Intraoperative Cardiovascular Response and Postoperative Recovery in Patients Undergoing Cardiac Surgery: A Retrospective Cohort Study

Objective

To investigate the correlation between the amount of sufentanil used during anesthesia and intraoperative hemodynamic fluctuation and postoperative recovery in patients undergoing cardiopulmonary bypass (CPB).

Materials and Methods

A retrospective analysis was performed on 454 patients undergoing elective heart surgery under CPB. Patients were divided into two groups according to the amount of sufentanil used during anesthesia: Group L (induced sufentanil 0.4-0.6 ug /kg, maintained sufentanil 0.01-0.02 ug/kg/min, n = 223) and Group H (induced sufentanil 4-6 ug/kg, maintained sufentanil 0.02-0.03 ug/kg/min, n = 231). Propensity score matching (PSM) was used at a 1:1 nearest-neighbor ratio to compare the two groups. Intraoperative use of vasoactive drugs, spontaneous heart rebound, secondary endotracheal intubation, postoperative mechanical ventilation time, the length of stay (LOS) in ICU, postoperative LOS in hospital, postoperative in-hospital mortality were analyzed.

Results

After matching, a total of 144 patients were included (72 patients in Group L, and 72 patients in Group H). Multivariate logistic regression analysis showed that the dosage of sufentanil during anesthesia was significantly correlated with the utilization rate of intraoperative vasoactive drugs (P < 0.001) and the success rate of spontaneous heart rebound (p = 0.001). The utilization rate of vasoactive drugs decreased significantly in Group H (OR, 0.062; 95% CI, 0.019-0.200) compared to that of Group L. The success rate of spontaneous heart rebound (OR, 0.187; 95% CI, 0.071-0.491) was higher in Group H. There were no differences on postoperative recovery outcomes between the two groups.

Conclusion

On the basis of our data, the use of high-dose sufentanil is beneficial to keep the cardiovascular response of patients in a stable state, but there is no significant effect on the quality of early postoperative recovery.

Development and Validation of Scores to Predict Prolonged Mechanical Ventilation after Cardiac Surgery

OBJECTIVES

To optimize the early prediction of prolonged postoperative mechanical ventilation after cardiac surgery (>24 hours postoperatively).

DESIGN

The authors performed a retrospective analysis.

SETTING

The Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) database was utilized.

PARTICIPANTS

All patients included in the ANZSCTS database between January 2015 and December 2018 were analyzed.

INTERVENTIONS

No interventions were performed in this observational study.

MEASUREMENTS AND MAIN RESULTS

A previously developed model was modified to allow retrospective risk calculation and model assessment (Modified Hessels score). The database was split into development and validation sets. A new risk model was developed using forward and backward stepwise elimination (ANZ-PreVent score). The authors assessed 48,382 patients, of whom 5004 (10.3%) were ventilated mechanically for >24 hours post-operatively. The Modified Hessels score demonstrated good performance in this database, with a c-index of 0.78 (95% CI 0.77-0.78) and a Brier score of 0.08. The newly developed ANZ-PreVent score demonstrated better performance (validation cohort, n = 12,229), with a c-index of 0.84 (95% CI 0.83-0.85) (p < 0.0001) and a Brier score of 0.07. Both scores performed better than the severity of illness scores commonly used to predict outcomes in intensive care.

CONCLUSIONS

The authors validated a modified version of an existing prediction score and developed the ANZ-PreVent score, with improved performance for identifying patients at risk of ventilation for >24 hours. The improved score can be used to identify high-risk patients for targeted interventions in future randomized controlled trials.

Comparison Between Fast-Track and Conventional Anesthesia for Children Undergoing Closure of Ventricular Septal Defects: A Systematic Review and Meta-Analysis

Ventricular septal defect (VSD) is common in pediatric patients. This study aimed to evaluate the safety and effectiveness of using fast-track anesthesia and comparing it to traditional anesthesia, among children undergoing a transthoracic device closure for VSD. A systematic review following the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was conducted. Relevant literature was identified through specific search terms in the Scopus, Medical Literature Analysis and Retrieval System Online (MEDLINE), Excerpta Medica database (Embase), Web of Science, The Cochrane Central Register of Controlled Trials (CENTRAL), and Google Scholar databases. The inclusion criteria focused on observational studies that compared fast-track anesthesia with conventional anesthesia in pediatric VSD closure cases. Data extraction, quality assessment, and meta-analysis were performed using standard differences in means. Initially, 6,535 papers were identified, and subsequent screening of titles and abstracts led to the inclusion of four retrospective studies from a total of 51 studies. The analysis encompassed 477 patients, with 235 in the fast-track anesthesia group and 242 in the conventional anesthesia group. No statistically significant disparities were observed between the two groups concerning the operative duration and hemodynamic variations post-intubation or post-procedure (P >0.05). Nevertheless, the fast-track anesthesia group demonstrated significantly reduced healthcare expenses as well as shorter periods of mechanical ventilation, ICU stay, and overall hospitalization compared to conventional anesthesia (P <0.05). The use of fast-track anesthesia in combination with transthoracic device closure for VSD demonstrates a safe and effective approach for pediatric patients. This approach results in reduced healthcare costs (10,000 Renminbi (RMB)) and shorter durations of mechanical ventilation, ICU admission, and hospitalization compared to conventional anesthesia. Further clinical trials are necessary to confirm these results and assess long-term outcomes.

Impact of Pulmonary Complications on Outcomes and Resource Use After Elective Cardiac Surgery

OBJECTIVE

To characterize the impact of pulmonary complications (PCs) on mortality, costs, and readmissions after elective cardiac operations in a national cohort and to test for hospital-level variation in PC.

BACKGROUND

PC after cardiac surgery are targets for quality improvement efforts. Contemporary studies evaluating the impact of PC on outcomes are lacking, as is data regarding hospital-level variation in the incidence of PC.

METHODS

Adults undergoing elective coronary artery bypass grafting and/or valve operations were identified in the 2016-2019 Nationwide Readmissions Database. PC was defined as a composite of reintubation, prolonged (>24 hours) ventilation, tracheostomy, or pneumonia. Generalized linear models were fit to evaluate associations between PC and outcomes. Institutional variation in PC was studied using observed-to-expected ratios.

RESULTS

Of 588,480 patients meeting study criteria, 6.7% developed PC. After risk adjustment, PC was associated with increased odds of mortality (14.6, 95% CI, 12.6-14.8), as well as a 7.9-day (95% CI, 7.6-8.2) increase in length of stay and $41,300 (95% CI, 39,600-42,900) in attributable costs. PC was associated with 1.3-fold greater hazard of readmission and greater incident mortality at readmission (6.7% vs 1.9%, P <0.001). Significant hospital-level variation in PC was present, with observed-to-expected ratios ranging from 0.1 to 7.7.

CONCLUSIONS

Pulmonary complications remain common after cardiac surgery and are associated with substantially increased mortality and expenditures. Significant hospital-level variation in PC exists in the United States, suggesting the need for systematic quality improvement efforts to reduce PC and their impact on outcomes.

Factors associated with long-term mechanical ventilation in patients undergoing cardiovascular surgery

BACKGROUND

One of the main therapy for coronary artery disease is surgery. Prolonged mechanical ventilation in patients with cardiac surgery is associated with high mortality. This study aimed to determine the factors related to long-term mechanical ventilation (LTMV) in patients undergoing cardiovascular surgery.

METHODS

The present study was a descriptive-analytical study in which the records of 1361 patients who underwent cardiovascular surgery and were on a mechanical ventilator during 2019-2020 at the Imam Ali Heart Center in Kermanshah city were examined. The data collection tool was a three-part researcher-made questionnaire including demographic characteristics, health records, and clinical variables. Data analysis was done using descriptive and inferential statistical tests and SPSS Version 25 software.

RESULTS

In this study, of the 1361 patients, 953 (70%) were male. The results indicated that 78.6% of patients had short-term mechanical ventilation, and 21.4% had long-term mechanical ventilation. There was a statistically significant relationship between the history of smoking, drug use, and baking bread with the type of mechanical ventilation (P < 0.05). Also, based on the regression test, some parameters, such as the history of respiratory conditions, could predict the prolongation of mechanical ventilation. Creatinine levels before surgery, chest secretions after surgery, central venous pressure after surgery, and the status of cardiac enzymes before surgery also affect this issue.

CONCLUSION

This study investigated some factors related to prolonged mechanical ventilation in patients undergoing heart surgery. For optimizing the care and therapeutic measures, It is suggested, healthcare workers have a detailed assessment on patients with factors such as the history of baking bread, history of obstructive pulmonary disease, history of kidney disease, use of an intra-aortic pump, number of respirations and systolic blood pressure 24 h after surgery, creatinine level 24 h after surgery, chest secretions after surgery, and the amount of pre-operative ejection fraction and cardiac enzymes (CK-MB).

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

OBJECTIVES

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

DESIGN

A retrospective cohort study.

SETTING

At a university hospital.

PARTICIPANTS

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

INTERVENTIONS

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

MEASUREMENTS AND MAIN RESULTS

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

CONCLUSIONS

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

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Risk factors associated with postoperative respiratory failure in tuberculous empyema patients

Our objective was to identify independent risk factors for predicting which patients in the Chinese population would likely develop respiratory failure.A descriptive analysis was conducted of demographic and clinical data of patients with tuberculous empyema (TE) admitted to the Beijing Chest Hospital, Capital Medical University between January 2001 and January 2020. Risk factors associated with postsurgical respiratory failure in TE patients were identified based on results of analyses based on univariable and multivariable logistic regression models.A total of 139 TE patients who underwent surgical treatment in the Beijing Chest Hospital, Capital Medical University from January 2001 to January 2020 were enrolled in this study. Cases included 109 male and 30 female patients, with an overall mean age (range 17-73) of 39.3 years. Of 139 TE patients, 26 (18.7%) experienced respiratory failure after surgery. Among significant risk factors for postsurgical respiratory failure, intraoperative blood loss volume greater than 1000 mL had the highest odds ratio value of 6.452. In addition, a pathologic preoperative pulmonary function test result showing a high partial pressure of carbon dioxide level was an independent risk factor for respiratory failure. Moreover, the presence of tuberculosis lesions in the contralateral lung was another significant risk factor for respiratory failure, as determined using multivariate analysis.Respiratory failure is a predominant complication experienced by TE patients undergoing surgery. High intraoperative blood loss, high preoperative high partial pressure of carbon dioxide level, and tuberculosis lesion(s) in the contralateral lung of TE patients were associated with increased risk of postoperative respiratory failure.

Extubation in the Operating Room After Transapical Transcatheter Aortic Valve Implantation Safely Improves Time-Related Outcomes and Lowers Costs: A Propensity Score-Matched Analysis

OBJECTIVE

The experience of safe extubation in the operating room (OR) after transcatheter aortic valve implantation (TAVI) procedure remains not well established. The authors conducted this study to assess the effect of OR extubation in comparison with extubation in the intensive care unit (ICU) on the outcomes and cost in patients undergoing transapical-TAVI.

DESIGN

A propensity score-matched analysis.

SETTING

A single major urban teaching and university hospital.

PARTICIPANTS

A total of 266 patients undergoing transapical TAVI under general anesthesia between June 2015 and March 2020.

INTERVENTIONS

Propensity matching on pre- and intraoperative variables was used to identify 99 patients undergoing extubation in the OR versus 72 undergoing extubation in the ICU for outcome analysis.

MEASUREMENTS AND MAIN RESULTS

After matching, extubation in the OR showed significant reductions of length of stay (LOS) in ICU (38.8 ± 17.4 v 58.0 ± 70.0 h, difference -19.2, 95% confidence interval [CI] -35.7 to -2.7, p = 0.009) and postoperative LOS in hospital (7.1 ± 3.9 v 10.1 ± 4.6 d, difference -3.0, 95% CI -4.3 to -1.7, p < 0.0001) compared with ICU extubation, but did not significantly affect the composite incidence of any postoperative complications (46.5% [46 of 99] v 52.8% [38 of 72], difference -6.3%, 95% CI -21.5 to 8.9, p = 0.415). Also, extubation in the OR led to significant reduction of total hospital cost compared with extubation in the ICU (¥303.5 ± 17.3 v ¥329.9 ± 52.3 thousand, difference -26.2, 95% CI -38.8 to -13.7, p < 0.0001).

CONCLUSIONS

The current study provided evidence that extubation in the OR could be performed safely without increases in morbidity, mortality, or reintubation rate and could provide cost-effective outcome benefits in patients undergoing transapical-TAVI.

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.

Automated Fastener vs Hand-tied Knots in Heart Valve Surgery: A Systematic Review and Meta-analysis

BACKGROUND

Although several studies revealed that the Cor-knot automated fastener (LSI Solutions, Victor, NY) reduces aortic cross-clamp and cardiopulmonary bypass times, the influence of the device on postoperative morbidity and mortality still needs to be evaluated. The aim of this study was to verify the hypothesis that the use of the Cor-knot device for heart valve surgery reduces aortic cross-clamp and cardiopulmonary bypass times, and this time saving translates into reduced morbidity and mortality.

METHODS

Retrospective cohort studies and randomized controlled trials reporting on the use of the automated fastener vs hand-tied knots were reviewed. The following end points were compared: aortic cross-clamp and cardiopulmonary bypass times, postoperative valvular regurgitation, postoperative ejection fraction, prolonged ventilator support, renal failure, and mortality.

RESULTS

Eight studies reporting data on 942 patients were included in the final analysis. The Cor-knot device was associated with shorter cardiopulmonary bypass (mean difference [MD], -11.74; 95% confidence interval [CI], -14.54 to -8.93; P < .00001) and aortic cross-clamp times (MD, -14.36; 95% CI, -19.63 to -9.09; P < .00001) in minimally invasive heart valve procedures. Overall, lower rates of postoperative valvular regurgitation (risk ratio [RR], 0.40; 95% CI, 0.26 to 0.62; P < .0001) and prolonged ventilator support (RR, 0.29; 95% CI, 0.13 to 0.65; P = .003) were observed. No difference was observed in postoperative atrial fibrillation, ejection fraction, renal failure, and mortality.

CONCLUSIONS

The use of the Cor-knot device in heart valve surgery reduced aortic cross-clamp and cardiopulmonary bypass times. Furthermore, as compared with hand-tie methods, the automated fastener may lead to decreased rates of prolonged ventilator support and valvular regurgitation while being noninferior in terms of other postoperative outcomes and mortality.

Perioperative care in cardiac surgery

As mortality is now low for many cardiac surgical procedures, there has been an increasing focus on patient centered outcomes such as recovery and quality of life. The Enhanced Recovery After Surgery (ERAS) cardiac society recently published the first set of guidelines for cardiac surgery which will be useful as a starting point to help translate this philosophy for the benefit of those undergoing cardiac surgery. At the same time there are many advances in other areas such as mechanical circulation, diagnostics and quality metrics. We intend here to present a balanced and evidenced based review of selected aspects of current practice, encompassing both UK and international perioperative care with a focus on recent advances. For the convenience of the reader we will adopt the conventional perioperative preoperative, intraoperative and postoperative phases of care. The focus of cardiac surgical practice needs to evolve from mortality to recovery. Those specialists who work in cardiac anaesthesia and critical care are well placed to contribute to these changes. Accompanying this work is the development of technologies to improve recognition of and intervention to prevent early organ dysfunction. Measuring, benchmarking and publishing quality outcomes from cardiac surgical centres is likely to improve services and benefit our patients.

Adverse Outcomes Associated With Delaying or Withholding β-Blockers After Cardiac Surgery: A Retrospective Single-Center Cohort Study

BACKGROUND

Ideal timing of postoperative β-blockers is unclear. We hypothesized that patients who do not receive β-blockers immediately after cardiac surgery would have increased in-hospital mortality (primary outcome) and postoperative hemodynamic, pulmonary, neurologic, or respiratory complications (secondary outcomes).

METHODS

We performed a retrospective cohort study evaluating patients who underwent cardiac surgery at our institution from January 1, 2013 to September 30, 2017. We compared outcomes between patients who received β-blockers by postoperative day (POD) 5 with outcomes in patients who did not receive β-blockers at any time or received them after POD 5. Inverse probability of treatment weighting was used to minimize confounding. Univariate logistic regression analyses were performed on the weighted sets using absent or delayed β-blockers as the independent variable and each outcome as dependent variables in separate analyses. A secondary analysis was performed in patients prescribed preoperative β-blockers. E-values were calculated for significant outcomes.

RESULTS

All results were confounder adjusted. Among patients presenting for cardiac surgery, not receiving β-blockers by POD 5 or at any time was not associated with the primary outcome in-hospital mortality, estimated odds ratio (OR; 99.5% confidence interval [CI]) of 1.6 (0.49-5.1), P = .28. Not receiving β-blockers by POD 5 or at any time was associated with postoperative atrial fibrillation, estimated OR (99.5% CI) of 1.5 (1.1-2.1), P < .001, and pulmonary complications, estimated OR (99.5% CI) of 3.0 (1.8-5.2), P < .001. E-values were 2.4 for postoperative atrial fibrillation and 5.6 for pulmonary complications. Among patients presenting for cardiac surgery taking preoperative β-blockers, not receiving β-blockers by POD 5 or at any time was not associated with the primary outcome mortality, with estimated OR (99.5% CI) of 1.3 (0.43-4.1), P = .63. In this subset, not receiving β-blockers by POD 5 or at any time was associated with increased adjusted ORs of postoperative atrial fibrillation (OR = 1.6; 99.5% CI, 1.1-2.4; P < .001) and postoperative pulmonary complications (OR = 2.8; 99.5% CI, 1.6-5.2; P < .001). Here, e-values were 2.7 for postoperative atrial fibrillation and 5.1 for pulmonary complications. For the sensitivity analyses for secondary outcomes, exposure and outcome periods overlap. Outcomes may have occurred before or after postoperative β-blocker administration.

CONCLUSIONS

Among patients who undergo cardiac surgery, not receiving postoperative β-blockers within the first 5 days after cardiac surgery or at any time is not associated with in-hospital mortality and is associated with, but may not necessarily cause, postoperative atrial fibrillation and pulmonary complications.

Predictors and outcomes of postoperative respiratory failure after cardiac surgery

BACKGROUND

Postoperative respiratory failure after cardiac surgery (CS-PRF) is a devastating complication and its incidence and predictors vary depending on how it is defined and the patient population.

AIMS

This study was conducted to determine the incidence, predictors and outcomes of CS-PRF defined as prolonged mechanical ventilation >48 hours and reintubation.

METHODS

This is a retrospective chart review of 1257 patients who underwent cardiac surgery between June 2011 and December 2018. The research questions were addressed through bivariate inferential, descriptive and binary logistic regression.

RESULTS

The overall incidence of CS-PRF was 15.9% and significant regression predictors included diabetes mellitus (OR = 1.77, P = .001), preoperative renal replacement therapy (OR = 2.07, P = .033), need for intraoperative transfusion (OR = 2.35, P = .000), combined coronary bypass/valvular surgery (OR = 2.61, P = .001) and intra-aortic balloon pump (OR = 3.60, P = .000). CS-PRF patients had increased postoperative blood transfusions (69.5% vs 27.9%, P = .000), reoperation for bleeding (9.0 vs 0.4%, P = .000), pleural effusion (13.5% vs 4.1%, P = .000), pneumonia (33.5% vs 1.6%, P = .000), acute kidney injury (70.9% vs 39.9%, P = .000), atrial fibrillation (42.5% vs 26.3%, P = .000), coma/encephalopathy (21.5% vs 3.3%, P = .000) and cerebrovascular accident (6.0% vs 1.3%, P = .000). They also had longer intensive care (262.1 vs 97.4 hours, P = .000) and hospital lengths of stay (17 vs 8 days, P = .000), and increased in-hospital mortality (17.5% vs 0.4%, P = .000). Survivors of CS-PRF were less likely to be discharged home (38.0% vs 84.4%, P = .000).

CONCLUSIONS

Knowledge of predictors for CS-PRF may help identify patients who are at risk for this complication and who may benefit from preventive measures to promote early extubation and to avert reintubation.

Effect of remifentanil-based fast-track anesthesia on postoperative analgesia and sedation in adult patients undergoing transthoracic device closure of ventricular septal defect

Objective

To investigate the effect of remifentanil-based fast-track anesthesia on analgesia and sedation after transthoracic device closure of ventricular septal defects (VSDs) in adult patients.

Methods

A retrospective analysis was performed on 59 patients aged 21–53 years who underwent transthoracic device closure of VSDs from January 2019 to September 2019. According to the different anesthesia strategies, the patients were divided into the R group (using remifentanil-based anesthesia, n = 33) and the S group (using sufentanil-based anesthesia, n = 26). Patient-related clinical data, postoperative analgesia, and sedation scores were collected and analyzed.

Results

There was no significant difference in age, gender, body weight, and operation time between the group R and the group S (P > 0.05). There was also no significant difference in intraoperative hemodynamic changes, BIS scores, postoperative analgesia, and sedation scores between the two groups (P > 0.05). The duration of mechanical ventilation, the length of ICU stay, and hospital stay in the group R were significantly lower than those in the group S (P < 0.05).

Conclusion

Remifentanil-based fast-track anesthesia is effective for adult patients undergoing transthoracic device closure of VSDs, which may shorten the mechanical ventilation duration, the ICU and hospital stay of patients.

Early Extubation in Enhanced Recovery from Cardiac Surgery

Prolonged intubation and mechanical ventilation following cardiac surgery have been associated with increased hospital and intensive care unit length of stays; higher health care costs; and morbidity resulting from atelectasis, intrapulmonary shunting, and pneumonia. Early extubation was developed as a strategy in the 1990s to reduce the high-dose opiate regimes and long ventilator times. Early extubation is a key component of the enhanced recovery pathway following cardiac surgery and enables early mobilization and early return to a normal diet. The plan to extubate should start as soon as the patient is scheduled for cardiac surgery and continue throughout the perioperative period.

Validation of Cardiac Surgery Score (CASUS) in Postoperative Cardiac Patients

Introduction. Cardiac Surgery Score (CASUS) was introduced in 2005 as the first postoperative scoring system specific for patients who had cardiac surgery. Prior to this, European System for Cardiac Operative Risk Evaluation (EuroSCORE) has been used preoperatively, while Intensive Care National Audit and Research Centre Score (ICNARC) and Acute Physiology and Chronic Health Evaluation II (APACHE II) scores, which are widely used in general intensive care unit population, have been used to score cardiac patients postoperatively. The development of CASUS by Hekmat and colleagues for use in postoperative cardiac patients aims to change this. We wanted to validate CASUS against the well-established preoperative Logistic EuroSCORE, and postoperative APACHE II and ICNARC scores. Method. Institutional approval for this study was granted by the Audit and Clinical Governance Committee. We analyzed prospectively collected data of patients who had cardiac surgery in Castle Hill Hospital between January 2016 and September 2018. All patients who underwent surgery in the unit would have had Logistic EuroSCORE, APACHE, and ICNARC scores calculated as standard. CASUS was then calculated for these patients based on their day 1 postoperative variables. The scoring systems were compared and data presented as area under the receiver operating characteristic curve. Result. Our study shows that CASUS is the best predictor of mortality followed by ICNARC, Logistic EuroSCORE, and APACHE II. ICNARC score remains the most accurate predictor of renal and pulmonary complication followed by CASUS. Conclusion. CASUS is a useful scoring system in post-cardiac surgery patients. The accuracy of CASUS and ICNARC scores in predicting mortality, pulmonary, and renal complications are comparable.

Benefits of ultra-fast-track anesthesia for children with congenital heart disease undergoing cardiac surgery

BACKGROUND

To compare the outcomes of ultra-fast-track anesthesia (UFTA) and conventional anesthesia in cardiac surgery for children with congenital heart disease (CHD) and low birth weight.

METHODS

One hundred and ninety-four CHD children, aged 6 months to 2 years, weighting 5 to 10 kg, were selected for this study. The 94 boys and 100 girls with the American Society of Anesthesiologists (ASA) physical status III and IV were randomly divided into two groups each consisting of 97 patients, and were subjected to ultra-fast-track and conventional anesthesia for cardiac surgery. For children in UFTA group, sevoflurane was stopped when cardiopulmonary bypass (CPB) started and cis-atracurium was stopped at the beginning of rewarming, and remifentanil (0.3 μg/kg/mim) was then infused. Propofol and remifentanil were discontinued at skin closure. 10 min after surgery, extubation was performed in operating room. For children in conventional anesthesia group, anesthesia was given routinely and they were directly sent to ICU with a tracheal tube. Extubation time, ICU stay and hospital stay after operation were recorded. Sedation-agitation scores (SAS) were assessed and adverse reactions as well as other anesthesia -related events were recorded.

RESULTS

The extubation time, ICU stay and hospital stay were significantly shorter in UFTA group (P < 0.05) and SAS at extubation was lower in UFTA group than in conventional anesthesia group, but similar in other time points. For both groups, no airway obstruction and other serious complications occurred, and incidence of other anesthesia -related events were low.

CONCLUSIONS

UFTA shortens extubation time, ICU stay and hospital stay for children with CHD and does not increase SAS and incidence of adverse reactions.

Prediction of Postoperative Outcomes and Long-Term Survival in Cardiac Surgical Patients Using the Intensive Care National Audit & Research Centre Score

OBJECTIVES

Scoring systems used in cardiac surgery, such as the European System for Cardiac Operative Risk Evaluation and the Society of Thoracic Surgeons scoring systems, do not adjust for events that take place intraoperatively. The authors hypothesized that intensive care unit scoring systems such as the Intensive Care National Audit & Research Centre (ICNARC) could predict accurately not only in-hospital mortality, but also other significant complications, as well as long-term survival after cardiac surgery.

DESIGN

Prospective cohort study using perioperative data from the ICNARC Audit and Dendrite database.

SETTING

Single tertiary referral cardiac surgery center.

PARTICIPANTS

A total of 4,446 consecutive cardiac surgical patients who had surgery between January 2011 and April 2018.

INTERVENTIONS

Comparison of scoring systems to predict postoperative outcomes.

MEASUREMENTS AND RESULTS

Receiver operating curves (ROCs) were used to evaluate how well the ICNARC scores predicted in-hospital mortality and postoperative complications (renal failure, pulmonary complications, gastrointestinal complications, and multiorgan failure). Cox regression analysis was used to determine factors affecting long-term survival. The C-indices for the ROC graphs for the ICNARC score were 0.840 for in-hospital mortality, 0.858 for renal failure, 0.665 for pulmonary complications, 0.764 for gastrointestinal complications, 0.702 for neurological complications in general and 0.654 for confusion, and 0.885 for multiorgan failure. From Cox regression analysis, the significant (p < 0.05) predictors of midterm mortality (5 years) were a higher ICNARC score, a higher age at surgery, chronic obstructive pulmonary disease, preoperative renal failure, preoperative neurological comorbidity, arteriopathy, and non-coronary artery bypass graft surgery.

CONCLUSION

The ICNARC scoring system is simple and can be used as an early warning screening tool to predict which patients are at higher risk for postoperative organ failure.

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.

Balancing intubation time with postoperative risk in cardiac surgery patients - a retrospective cohort analysis

Introduction

Intubation time in patients undergoing cardiac surgery may be associated with increased mortality and morbidity. Premature extubation can have serious adverse physiological consequences. The aim of this study was to determine the influence of intubation time on morbidity and mortality in patients undergoing cardiac surgery.

Methods

We performed a retrospective analysis of data on 1,904 patients undergoing isolated coronary artery bypass grafting (CABG) and stratified them by duration of intubation time after surgery - 0-6, 6-9, 9-12, 12-24 and over 24 hours. Postoperative complications risk analysis was performed using multivariate logistic regression analysis for patients extubated ≤12 and >12 hours.

Results

Intubation percentages in each time cohort were as follows: 0-6 hours - 7.8%, 6-9 hours - 17.3%, 9-12 hours - 26.8%, 12-24 hours - 44.4% and >24 hours - 3.7%. Patients extubated ≤12 hours after CABG were younger, mostly males, more often smokers, with lower preoperative risk. They had lower 30-day mortality (2.02% vs 4.59%, P=0.002), shorter hospital stay (7.68±4.49 vs 9.65±12.63 days, P<0.001) and shorter intensive care unit stay (2.39 vs 3.30 days, P<0.001). Multivariate analysis showed that intubation exceeding 12 hours after CABG increases the risk of postoperative delirium (OR 1.548, 95% CI 1.161-2.064, P=0.003) and risk of postoperative hemofiltration (OR 1.302, 95% CI 1.023-1.657, P=0.032).

Conclusion

Results indicate that risk of postoperative complications does not increase until intubation time exceeds 12 hours. Shorter intubation time is seen in younger, men and smokers. Intubation time >12 hours is a risk factor for postoperative delirium and hemofiltration after cardiac surgery.

Perioperative Sedation in Mechanically Ventilated Cardiac Surgery Patients With Dexmedetomidine-Based Versus Propofol-Based Regimens

BACKGROUND

Sedative agents used during cardiac surgery can influence the patient's time to extubation, intensive care unit (ICU) and hospital length of stay, and incidence of delirium.

OBJECTIVE

This study evaluates the effects of the intraoperative and postoperative use of dexmedetomidine versus propofol infusions.

METHODS

This 19-month retrospective observational study at an academic medical center included 278 patients 18 years of age or older who underwent coronary artery bypass grafting (CABG), valve replacement surgery, or combined CABG plus valve surgery, who received either a dexmedetomidine or propofol infusion in addition to general anesthesia intraoperatively. The primary outcome was time to extubation. The secondary outcomes were ICU and hospital length of stay and incidence of delirium.

RESULTS

Use of dexmedetomidine (n = 69) as an intraoperative and postoperative sedative as opposed to propofol (n = 209) was significantly associated with increased likelihood of extubation (ie, shorter time to extubation; hazard ratio = 1.63, 95% CI = 1.21-2.19, P = 0.001). There was no significant association between use of dexmedetomidine and ICU discharge ( P = 0.99), hospital discharge ( P = 0.52), and incidence of delirium ( P = 0.27) after adjusting for other covariates. Conclusion and Relevance: Dexmedetomidine increased the likelihood of extubation when compared with propofol, with no increase in ICU or hospital length of stay or incidence of delirium. Our study is unique in that there was no crossover between patients who received dexmedetomidine and propofol infusions intraoperatively and postoperatively Dexmedetomidine-based regimens could serve as a suitable alternative to propofol-based regimens for fast-track extubation.

Epidemiological characteristics of and risk factors for patients with postoperative acute kidney injury: a multicenter prospective study in 30 Chinese intensive care units

BACKGROUND

Although there were studies to investigate the risk factors for acute kidney injury (AKI) after surgery, most of them focused on one specific type of surgeries. The risk factors for postoperative AKI in patients undergoing all surgeries in intensive care units (ICU) have not been reported.

METHODS

Data from 1731 patients undergoing surgery in 30 ICUs of 28 tertiary hospitals in Beijing from March to August 2012 were prospectively collected. AKI was defined and staged by the KDIGO criteria. Multivariate logistic regression analysis was performed to assess independent risk factors for postoperative AKI.

RESULTS

Postoperative AKI occurred in 44.8% of patients (stage 1 54.8%; stage 2 21.9%, stage 3 23.3%). Cardiovascular surgery was identified as an independent factor for postoperative AKI as well as emergency surgery [odds ratio (OR) 1.403], nephrotoxic drugs (OR 1.303), APACHE II score (OR 1.055), SOFA score (OR 1.115), duration for positive fluid balance (OR 1.165), use of diuretics (OR 2.293), sepsis (OR 1.501), and CKD (OR 4.517). AKI stage 3 versus stages 1-2 was associated with higher mortality in ICU, hospital, and 28-day follow-up after cardiovascular, abdominal, limb, and chest surgeries, while this was not observed after neurosurgery or other surgeries.

CONCLUSION

Risk factors for AKI in ICU patients after different types of surgery were identified. This might be the first step to reduce the high incidence of AKI after surgery. The presence of AKI in ICU patients was associated with higher mortality after most types of surgery, but not after neurosurgery.

TRIAL REGISTRATION

ChiCTR-ONC-11001875.

The level of urinary IL-18 in acute kidney injury after cardiopulmonary bypass

This study investigated the diagnostic value of urinary interleukin-18 (uIL-18) in acute kidney injury (AKI) after cardiopulmonary bypass (CPB) in clinical practice. A total of 103 patients who underwent CPB were divided into the AKI group and non-AKI group according to the diagnostic criteria of AKI, and we collected the urine samples before and at 2, 4, 6, 8 and 12 h after CPB and the blood samples before and at 12, 24, 48 and 72 h after CPB for detection of the levels of uIL-18 and urinary neutrophil gelatinase-associated lipocalin (uNGAL) in urine samples and the levels of serum creatinine (Scr) in blood samples, respectively. With the results of detection, we measured the sensitivity and specificity of uIL-18 and uNGAL levels at 2 h after CPB in early diagnosis of AKI using the receiver operating characteristic (ROC) curve and area under curve (AUC). There were a total of 22 patients (21.4%) with AKI. From 12 h after CPB, the level of Scr in the AKI group was significantly elevated, and this increasing trend lasted for 60 h; comparisons with the levels before CPB and in non-AKI group showed that the differences had statistical significance (P<0.05). In AKI group, uIL-18 attained the peak level at 2 h after CPB, and the high level lasted for 10 h; comparisons with the levels before CPB and in non-AKI group showed that the differences had statistical significance (P<0.05); 2 h after CPB, the AUC was 90.48, and when the critical value was set as 1.6 µg/l, the sensitivity and specificity was 90.91 and 91.36%, respectively. Although there was a significant elevation in uNGAL level at 2 h after CPB in the AKI group, the level was dramatically decreased as soon as the peak level was attained at 4 h, and the high level only lasted for 8 h; difference between the level at 2 h after CPB and the level before CPB as well as that in the non-AKI group had statistical significance (P<0.05); at 2 h after CPB, the AUC was 83.25, and when the critical value was set as 100 µg/l, the sensitivity and specificity was, respectively 90.91 and 93.83%. The results indicated that after CPB, the level of uIL-18 shows a more promising diagnostic value in clinical practice than Scr and uNGAL in early diagnosis of AKI.

Impact of Obesity on Intensive Care Unit Resource Utilization After Cardiac Operations

BACKGROUND

Much has been published about the effect of obesity on adverse outcomes after cardiac operations, yet little is known regarding the effect of obesity on intensive care unit (ICU) resource utilization. This study examined the effect of obesity on ICU resource utilization after cardiac operations.

METHODS

All patients with a body mass index (BMI) of 18.5 kg/m² or higher who underwent a cardiac surgical procedure between 2006 and 2013 were stratified into the following weight categories: normal (BMI 18.5 to 24.99 kg/m²), preobese (BMI 25 to 29.99 kg/m²), obese class I (BMI 30 to 34.99 kg/m²), obese class II (BMI 35 to 39.99 kg/m²), and obese class III (BMI ≥40 kg/m²). Comparisons between weight categories were done, and the risk-adjusted effect of weight category on prolonged ICU stay, prolonged ventilation, and ICU readmission was determined.

RESULTS

Of the 5,365 included patients, 1,948 were obese. Patients with greater obesity experienced longer ICU time, longer ventilation time, and increased ICU readmission. After adjustment, increasing obesity remained independently associated with greater likelihood of prolonged ICU stay (obese class II: odds ratio [OR], 2.4; 95% confidence interval [CI], 1.55 to 3.61; obese class III: OR, 4.1; 95% CI, 2.38 to 7.05), prolonged ventilation (obese class III: OR, 3.4; 95% CI, 1.57 to 7.22), and ICU readmission (obese class II: OR, 3.0; 95% CI, 1.70 to 5.31; obese class III: OR, 2.9; 95% CI, 1.32 to 6.36).

CONCLUSIONS

Increasing obesity was associated with a significant increase in ICU resource utilization after cardiac operations. Further study is needed to determine the mechanisms underlying this association and how the adverse effects of obesity may be mitigated.

Benefits of ultra-fast-track anesthesia in left ventricular assist device implantation: a retrospective, propensity score matched cohort study of a four-year single center experience

BACKGROUND

The use of left ventricular assist devices (LVADs) has gained significant importance for treatment of end-stage heart failure. Fast-track procedures are well established in cardiac surgery, whereas knowledge of their benefits after LVAD implantation is sparse. We hypothesized that ultra-fast-track anesthesia (UFTA) with in-theater extubation or at a maximum of 4 h. after surgery is feasible in Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) level 3 and 4 patients and might prevent postoperative complications.

METHODS

From March, 2010 to March, 2012, 53 LVADs (50 Heart Mate II and 3 Heart Ware) were implanted in patients in our department. UFTA was successfully performed (LVAD _ultra ) in 13 patients. After propensity score matching, we compared the LVAD _ultra group with a matched group (LVAD _match ) receiving conventional anesthesia management.

RESULTS

Patients in the LVAD _ultra group had significantly lower incidences of pneumonia (p = 0.031), delirium (p = 0.031) and right ventricular failure (RVF) (p = 0.031). They showed a significantly higher cardiac index in the first 12 h. (p = 0.017); a significantly lower central venous pressure during the first 24 h. postoperatively (p = 0.005) and a significantly shorter intensive care unit (ICU) stay (p = 0.016). Kaplan-Meier analysis after four years of follow-up showed no significant difference in survival.

CONCLUSION

In this pilot study, we demonstrated the feasibility of ultra-fast-track anesthesia in LVAD implantation in selected patients with INTERMACS level 3-4. Patients had a lower incidence of postoperative complications, better hemodynamic performance, shorter length of ICU stay and lower incidence of RVF after UFTA. Prospective randomized investigations should examine the preservation of right ventricular function in larger numbers and identify appropriate selection criteria.

Pulmonary Perfusion and Ventilation during Cardiopulmonary Bypass Are Not Associated with Improved Postoperative Outcomes after Cardiac Surgery

OBJECTIVES

Clinical trials of either pulmonary perfusion or ventilation during cardiopulmonary bypass (CBP) are equivocal. We hypothesized that to achieve significant improvement in outcomes both interventions had to be concurrent.

DESIGN

Retrospective case-control study.

SETTINGS

Major academic tertiary referral medical center.

PARTICIPANTS

Two hundred seventy-four consecutive patients who underwent open heart surgery with CBP 2009-2013.

INTERVENTIONS

The outcomes of 86 patients who received pulmonary perfusion and ventilation during CBP were retrospectively compared to the control group of 188 patients.

MEASUREMENTS AND MAIN RESULTS

Respiratory complications rates were similar in both groups (33.7 vs. 33.5%), as were the rates of postoperative pneumonia (4.7 vs. 4.3%), pleural effusions (13.9 vs. 12.2%), and re-intubations (9.3 vs. 9.1%). Rates of adverse postoperative cardiac events including ventricular tachycardia (9.3 vs. 8.5%) and atrial fibrillation (33.7 vs. 28.2%) were equivalent in both groups. Incidence of sepsis (8.1 vs. 5.3%), postoperative stroke (2.3 vs. 2.1%), acute kidney injury (2.3 vs. 3.7%), and renal failure (5.8 vs. 3.7%) was likewise comparable. Despite similar transfusion requirements, coagulopathy (12.8 vs. 5.3%, p = 0.031) and the need for mediastinal re-exploration (17.4 vs. 9.6%, p = 0.0633) were observed more frequently in the pulmonary perfusion and ventilation group, but the difference did not reach the statistical significance. Intensive care unit (ICU) and hospital stays, and the ICU readmission rates (7.0 vs. 8.0%) were similar in both groups.

CONCLUSION

Simultaneous pulmonary perfusion and ventilation during CBP were not associated with improved clinical outcomes.

Preoperative maximal expiratory pressure is associated with duration of invasive mechanical ventilation after cardiac surgery: An observational study

OBJECTIVE

To evaluate the association of maximal expiratory pressure (MEP), maximal inspiratory pressure (MIP), and peak expiratory flow (PEF) with total duration of invasive mechanical ventilation (IMV) in subjects undergoing cardiac surgery.

BACKGROUND

Prolonged IMV is associated with respiratory infections, prolonged hospitalization, and increased mortality. Pulmonary function tests can help predict postoperative outcomes after cardiac surgery.

METHODS

We recruited subjects admitted for cardiac surgery. All MIP, MEP, and PEF measurements were performed before surgery. Multivariable analysis was performed using a multiple linear regression model to control for possible confounders and test for association of MIP, MEP, and PEF with IMV duration.

RESULTS

Overall, 125 subjects were included in the study. Higher MEP was associated with reduced duration of IMV after adjustment for confounders (P = 0.015), but no such association was observed between MIP or PEF and IMV.

CONCLUSIONS

In subjects undergoing elective cardiac surgery, preoperative MEP is associated with IMV duration.

Routine operation theatre extubation after cardiac surgery in the elderly

OBJECTIVES

The aim was to analyse in-hospital outcomes of patients over 70 years of age undergoing routine immediate operation theatre (OT) extubation after on-pump or off-pump cardiac surgery.

METHODS

A retrospective analysis was performed of prospectively collected data over a 4-year period (2011-14) from elderly patients undergoing early extubation after cardiac surgery at a single institution. All patients over 70 years were considered eligible for immediate OT or intensive care unit (ICU) early extubation after meeting specific criteria. All types of non-emergency cardiac surgery were included. Cardiac surgical risk stratification was assessed with EuroSCORE II and age, creatinine level and left ventricular ejection fraction (ACEF) score.

RESULTS

Among the 415 patients operated on during the period, 275 (66.3%) were ≥70 years old. One hundred and forty patients (50.9%) of the elderly group were extubated successfully in the OT. Excluding off-pump coronary surgery, OT extubation was achieved in 51.5% of cases. The rate of risk of reintubation within 24 h of surgery after OT extubation was 2.1%. The in-hospital mortality rate was 4.7%, and the complication rate was 11.6%, independently of extubation timing. Elderly patients extubated in the OT had a significantly lower median EuroSCORE II risk level and ACEF score, more isolated valve surgeries, reduced cardiopulmonary bypass time, less complications and shorter length of stay than ICU-extubated patients. In the multivariate analysis, only the ACEF score remained as an independent variable associated with OT extubation in the elderly (odds ratio 25.0, 95% CI 2.74-228.8, P = 0.004), and had good discriminating power [receiver operating characteristics (ROC) area 0.713]. On the other hand, the EuroSCORE ROC area used to predict OT extubation was 0.694, and the cut-off analysis showed that a risk value under 2.11 was associated with 72.1% OT extubation versus 37.3% when the risk value was over 2.11 (P = 0.0002).

CONCLUSIONS

OT extubation in the elderly can be safely performed in nearly 50% of patients, without apparently worsening their outcomes. A key point of this success was the use of a short-acting volatile agent to maintain anaesthesia throughout the procedure. Low- or moderate-risk cardiac surgery assessed with a preoperative EuroSCORE II <2.11 will help to better predict successful OT extubation in the elderly.

The impact of off-pump surgery in end-organ function: practical end-points

Most surgeons perform coronary bypass surgery with the aid of cardiopulmonary bypass, which inflicts a massive systemic inflammatory response to the body leading to adverse clinical outcome. In an attempt to make CABG less invasive, interest have been diverted to the off pump technique.The current review attempts to bring an insight onto the last ten years knowledge on the off-pump impact in end organ function, with an aim to draw some clear conclusions in order to allow practitioners to reflect on the subject.

Predicting reintubation, prolonged mechanical ventilation and death in post-coronary artery bypass graft surgery: a comparison between artificial neural networks and logistic regression models

INTRODUCTION

In coronary artery bypass (CABG) surgery, the common complications are the need for reintubation, prolonged mechanical ventilation (PMV) and death. Thus, a reliable model for the prognostic evaluation of those particular outcomes is a worthwhile pursuit. The existence of such a system would lead to better resource planning, cost reductions and an increased ability to guide preventive strategies. The aim of this study was to compare different methods - logistic regression (LR) and artificial neural networks (ANNs) - in accomplishing this goal.

MATERIAL AND METHODS

Subjects undergoing CABG (n = 1315) were divided into training (n = 1053) and validation (n = 262) groups. The set of independent variables consisted of age, gender, weight, height, body mass index, diabetes, creatinine level, cardiopulmonary bypass, presence of preserved ventricular function, moderate and severe ventricular dysfunction and total number of grafts. The PMV was also an input for the prediction of death. The ability of ANN to discriminate outcomes was assessed using receiver-operating characteristic (ROC) analysis and the results were compared using a multivariate LR.

RESULTS

The ROC curve areas for LR and ANN models, respectively, were: for reintubation 0.62 (CI: 0.50-0.75) and 0.65 (CI: 0.53-0.77); for PMV 0.67 (CI: 0.57-0.78) and 0.72 (CI: 0.64-0.81); and for death 0.86 (CI: 0.79-0.93) and 0.85 (CI: 0.80-0.91). No differences were observed between models.

CONCLUSIONS

The ANN has similar discriminating power in predicting reintubation, PMV and death outcomes. Thus, both models may be applicable as a predictor for these outcomes in subjects undergoing CABG.

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.

Dysphagia and associated risk factors following extubation in cardiovascular surgical patients

Following cardiovascular (CV) surgery, prolonged mechanical ventilation of >48 h increases dysphagia frequency over tenfold: 51 % compared to 3-4 % across all durations. Our primary objective was to identify dysphagia frequency following CV surgery with respect to intubation duration. Our secondary objective was to explore characteristics associated with dysphagia across the entire sample. Using a retrospective design, we stratified all consecutive patients who underwent CV surgery in 2009 at our institution into intubation duration groups defined a priori: I (≤ 12 h), II (>12 to ≤ 24 h), III (>24 to ≤ 48 h), and IV (>48 h). Eligible patients were >18 years old who survived extubation following coronary artery bypass alone or cardiac valve surgery. Patients who underwent tracheotomy were excluded. Pre-, peri-, and postoperative patient variables were extracted from a pre-existing database and medical charts by two blinded reviewers. Disagreements were resolved by consensus. Across the entire sample, multivariable logistic regression analysis determined independent predictors of dysphagia. Across the entire sample, dysphagia frequency was 5.6 % (51/909) but varied by group: I, 1 % (7/699); II, 8.2 % (11/134); III, 16.7 % (6/36); and IV, 67.5 % (27/40). Across the entire sample, the independent predictors of dysphagia included intubation duration in 12-h increments (p < 0.001; odds ratio [OR] 1.93, 95 % confidence interval [CI] 1.63-2.29) and age in 10-year increments (p = 0.004; OR 2.12, 95 % CI 1.27-3.52). Patients had a twofold increase in their odds of developing dysphagia for every additional 12 h with endotracheal intubation and for every additional decade in age. These patients should undergo post-extubation swallow assessments to minimize complications.

Risk factors of prolonged mechanical ventilation following open heart surgery: what has changed over the last decade?

OBJECTIVE

To identify the risk factors for prolonged invasive mechanical ventilation after open heart surgery in Pakistan.

DESIGN

This study is based on retrospective analysis of database.

PLACE AND DURATION

We conducted study of all patients who underwent open heart surgery at CPE Institute of Cardiology, Multan from March 2009 to May 2011.

PATIENTS & METHODS

The data was retrieved from the database in the form of electronic spreadsheet which was then analyzed using SPSS software. The patients with incomplete data entries were removed from the analysis resulting in a set of 1,617 patients. The data of each patient consisted of 65 preoperative, operative and postoperative variables. The data was summarized as means, medians and standard deviations for numeric variables and frequencies and percentages or categoric variables. These risk factors were compared using Chi-sqaure test. Their ODDs ratios and 95% confidence intervals of ODD's Ratios and P values were calculated.

RESULTS

Out of a total of 1,617 patients, 77 patients (4.76%) had prolonged ventilation for a cumulated duration of more than over 24 hours. Preoperative renal failure, emphysema, low EF (<30%), urgent operation, preoperative critical state, prolonged bypass time, prolonged cross clamp time, complex surgical procedures and peri-operative myocardial infarction were found to be risk factors for PIMV. Old age, female gender, advanced ASA class, advanced NYHA class, diabetes mellitus, smoking, history of COPD, redo surgery, left main stenosis, obesity and use of intra-aortic balloon pump were not found to have significant ODDs ratios for PIMV. The patients with prolonged ventilation had significantly high mortality i.e. 32.47% while the normal ventilation group had 0.32% overall mortality.

CONCLUSIONS

Many of the previously considered risk factors for prolonged ventilation after open heart study are no more significant risk factors. However, prolonged ventilation continues to be associated with very high mortality.

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.