Early versus late extubation after coronary artery bypass grafting: effects on cognitive function

Fast tracking in cardiac surgery: is it safe?

Background

While fast track clinical pathways have been demonstrated to reduce resource utilization in patients undergoing cardiac surgery, it remains unclear as to whether they adversely affect post-operative outcomes. The purpose of this study was to determine the impact of fast tracking on post-operative outcomes following cardiac surgery.

Methods

In a retrospective study, all patients undergoing first-time, on-pump, non-emergent coronary artery bypass grafting, valve, or coronary artery bypass grafting + valve at a single centre between 2010 and 2017 were included. Patients were considered to have been fast tracked if they were extubated and transferred from intensive care to a step-down unit on the same day as their procedure. The risk-adjusted effect of fast tracking on a 30-day composite of all-cause mortality, stroke, renal failure, infection, atrial fibrillation, and readmission to hospital was determined. Furthermore, propensity score matching was used to match fasting track patients in a 1-to-1 manner with their nearest “neighbor” in the control group and subsequently compared in terms of 30-day post-operative outcomes.

Results

3252 patients formed the final study population (fast track: n = 245; control: n = 3007). Patients who were fast tracked experienced reduced time to initial extubation (4.3 vs. 5.6 h, p < 0.0001) and lower median initial intensive care unit length of stay (7.8 vs. 20.4 h, p < 0.0001). Fast tracked patients experienced lower 30-day rates of the composite outcome (42.4% vs. 51.5%, p = 0.008). However, following propensity score matching, fast tracked patients experienced similar 30-day rates of the composite outcome as the control group (42.4% vs. 44.5%, p = 0.72). After risk adjustment using multivariable regression modeling, fast tracking was predictive of an improved 30-day composite outcome (OR 0.75, 95% CI 0.57–0.98, p = 0.03).

Conclusion

Fast track clinical pathways was associated with reduced intensive care unit, overall length of stay and similar 30-day post-operative outcomes. These results suggest that fast tracking appropriate patients may reduce resource utilization, while maintaining patient safety.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-022-01815-9.

Impact of fast-track management on adult cardiac surgery: clinical and hospital outcomes

OBJECTIVE

To compare the impact of two fast-track strategies regarding the extubation time and removal of invasive mechanical ventilation in adults after cardiac surgery on clinical and hospital outcomes.

METHODS

This was a retrospective cohort study with patients undergoing cardiac surgery. Patients were classified according to the extubation time as the Control Group (extubated 6 hours after admission to the intensive care unit, with a maximum mechanical ventilation time of 18 hours), Group 1 (extubated in the operating room after surgery) and Group 2 (extubated within 6 hours after admission to the intensive care unit). The primary outcomes analyzed were vital capacity on the first postoperative day, length of hospital stay, and length of stay in the intensive care unit. The secondary outcomes were reintubation, hospital-acquired pneumonia, sepsis, and death.

RESULTS

For the 223 patients evaluated, the vital capacity was lower in Groups 1 and 2 compared to the Control (p = 0.000 and p = 0.046, respectively). The length of stay in the intensive care unit was significantly lower in Groups 1 and 2 compared to the Control (p = 0.009 and p = 0.000, respectively), whereas the length of hospital stay was lower in Group 1 compared to the Control (p = 0.014). There was an association between extubation in the operating room (Group 1) with reintubation (p = 0.025) and postoperative complications (p = 0.038).

CONCLUSION

Patients undergoing fast-track management with extubation within 6 hours had shorter stays in the intensive care unit without increasing postoperative complications and death. Patients extubated in the operating room had a shorter hospital stay and a shorter stay in the intensive care unit but showed an increase in the frequency of reintubation and postoperative complications.

Examining Health Care Costs: Opportunities to Provide Value in the Intensive Care Unit

As health care costs threaten the economic stability of American society, increasing pressures to focus on value-based health care have led to the development of protocols for fast-track cardiac surgery and for delirium management. Critical care services can be led by anesthesiologists with the goal of improving ICU outcomes and at the same time decreasing the rising cost of ICU medicine.

Fast-track cardiac care for adult cardiac surgical patients

BACKGROUND

Fast-track cardiac care is a complex intervention involving several components of care during cardiac anaesthesia and in the postoperative period, with the ultimate aim of early extubation after surgery, to reduce length of stay in the intensive care unit and in the hospital. Safe and effective fast-track cardiac care may reduce hospital costs. This is an update of a Cochrane review first published in 2003, updated in 2012 and updated now in 2016.

OBJECTIVES

To determine the safety and effectiveness of fast-track cardiac care compared with conventional (not fast-track) care in adult patients undergoing cardiac surgery. Fast-track cardiac care intervention includes administration of low-dose opioid-based general anaesthesia or use of a time-directed extubation protocol, or both.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2015, Issue 5), MEDLINE (January 2012 to May 2015), Embase (January 2012 to May 2015), the Cumulative Index to Nursing and Allied Health Literature (CINAHL; January 2012 to May 2015) and the Institute for Scientific Information (ISI) Web of Science (January 2012 to May 2015), along with reference lists of articles, to identify additional trials. We applied no language restrictions.

SELECTION CRITERIA

We included all randomized controlled trials of adult cardiac surgical patients (coronary artery bypass grafts, aortic valve replacement, mitral valve replacement) that compared fast-track cardiac care and conventional (not fast-track) care groups. We focused on the following fast-track interventions, which were designed for early extubation after surgery: administration of low-dose opioid-based general anaesthesia during cardiac surgery and use of a time-directed extubation protocol after surgery. The primary outcome was risk of mortality. Secondary outcomes included postoperative complications, reintubation within 24 hours of surgery, time to extubation, length of stay in the intensive care unit and in the hospital, quality of life after surgery and hospital costs.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted study data. We contacted study authors for additional information. We calculated a Peto odds ratio (OR) for risk of mortality and used a random-effects model to report risk ratio (RR), mean difference (MD) and 95% confidence intervals (95% CIs) for all secondary outcomes.

MAIN RESULTS

We included 28 trials (4438 participants) in the updated review. We considered most participants to be at low to moderate risk of death after surgery. We assessed two studies as having low risk of bias and 11 studies high risk of bias. Investigators reported no differences in risk of mortality within the first year after surgery between low-dose versus high-dose opioid-based general anaesthesia groups (OR 0.53, 95% CI 0.25 to 1.12; eight trials, 1994 participants, low level of evidence) and between a time-directed extubation protocol versus usual care (OR 0.80, 95% CI 0.45 to 1.45; 10 trials, 1802 participants, low level of evidence).Researchers noted no significant differences between low-dose and high-dose opioid-based anaesthesia groups in the following postoperative complications: myocardial infarction (RR 0.98, 95% CI 0.48 to 1.99; eight trials, 1683 participants, low level of evidence), stroke (RR 1.17, 95% CI 0.36 to 3.78; five trials, 562 participants, low level of evidence) and tracheal reintubation (RR 1.77, 95% CI 0.38 to 8.27; five trials, 594 participants, low level of evidence).Comparisons with usual care revealed no significant differences in the risk of postoperative complications associated with a time-directed extubation protocol: myocardial infarction (RR 0.59, 95% CI 0.27 to 1.31; eight trials, 1378 participants, low level of evidence), stroke (RR 0.85, 95% CI 0.33 to 2.16; 11 trials, 1646 participants, low level of evidence) and tracheal reintubation (RR 1.34, 95% CI 0.74 to 2.41; 12 trials, 1261 participants, low level of evidence).Although levels of heterogeneity were high, low-dose opioid anaesthesia was associated with reduced time to extubation (reduction of 4.3 to 10.5 hours, 14 trials, 2486 participants, low level of evidence) and length of stay in the intensive care unit (reduction of 0.4 to 7.0 hours, 12 trials, 1394 participants, low level of evidence). Use of a time-directed extubation protocol was associated with reduced time to extubation (reduction of 3.7 to 8.8 hours, 16 trials, 2024 participants, low level of evidence) and length of stay in the intensive care unit (reduction of 3.9 to 10.5 hours, 13 trials, 1888 participants, low level of evidence). However, these two fast-track care interventions were not associated with reduced total length of stay in the hospital (low level of evidence).

AUTHORS' CONCLUSIONS

Low-dose opioid-based general anaesthesia and time-directed extubation protocols for fast-track interventions have risks of mortality and major postoperative complications similar to those of conventional (not fast-track) care, and therefore appear to be safe for use in patients considered to be at low to moderate risk. These fast-track interventions reduced time to extubation and shortened length of stay in the intensive care unit but did not reduce length of stay in the hospital.

Risk Factors Associated with Cognitive Decline after Cardiac Surgery: A Systematic Review

Modern day cardiac surgery evolved upon the advent of cardiopulmonary bypass machines (CPB) in the 1950s. Following this development, cardiac surgery in recent years has improved significantly. Despite such advances and the introduction of new technologies, neurological sequelae after cardiac surgery still exist. Ischaemic stroke, delirium, and cognitive impairment cause significant morbidity and mortality and unfortunately remain common complications. Postoperative cognitive decline (POCD) is believed to be associated with the presence of new ischaemic lesions originating from emboli entering the cerebral circulation during surgery. Cardiopulmonary bypass was thought to be the reason of POCD, but randomised controlled trials comparing with off-pump surgery show contradictory results. Attention has now turned to the growing evidence that perioperative risk factors, as well as patient-related risk factors, play an important role in early and late POCD. Clearly, identifying the mechanism of POCD is challenging. The purpose of this systematic review is to discuss the literature that has investigated patient and perioperative risk factors to better understand the magnitude of the risk factors associated with POCD after cardiac surgery.

A Randomized Controlled Trial of Adaptive Support Ventilation Mode to Wean Patients after Fast-track Cardiac Valvular Surgery

Background:

Adaptive support ventilation can speed weaning after coronary artery surgery compared with protocolized weaning using other modes. There are no data to support this mode of weaning after cardiac valvular surgery. Furthermore, control group weaning times have been long, suggesting that the results may reflect control group protocols that delay weaning rather than a real advantage of adaptive support ventilation.

Methods:

Randomized (computer-generated sequence and sealed opaque envelopes), parallel-arm, unblinded trial of adaptive support ventilation versus physician-directed weaning after adult fast-track cardiac valvular surgery. The primary outcome was duration of mechanical ventilation. Patients aged 18 to 80 yr without significant renal, liver, or lung disease or severe impairment of left ventricular function undergoing uncomplicated elective valve surgery were eligible. Care was standardized, except postoperative ventilation. In the adaptive support ventilation group, target minute ventilation and inspired oxygen concentration were adjusted according to blood gases. A spontaneous breathing trial was carried out when the total inspiratory pressure of 15 cm H2O or less with positive end-expiratory pressure of 5 cm H2O. In the control group, the duty physician made all ventilatory decisions.

Results:

Median duration of ventilation was statistically significantly shorter (P = 0.013) in the adaptive support ventilation group (205 [141 to 295] min, n = 30) than that in controls (342 [214 to 491] min, n = 31). Manual ventilator changes and alarms were less common in the adaptive support ventilation group, and arterial blood gas estimations were more common.

Conclusion:

Adaptive support ventilation reduces ventilation time by more than 2 h in patients who have undergone fast-track cardiac valvular surgery while reducing the number of manual ventilator changes and alarms.

Fast-track cardiac care for adult cardiac surgical patients

BACKGROUND

Fast-track cardiac care is a complex intervention involving several components of care during cardiac anaesthesia and in the postoperative period, all with the ultimate aim of early extubation after surgery, to reduce the length of stay in the intensive care unit and in the hospital. Safe and effective fast-track cardiac care may reduce hospital costs. This is an update of a Cochrane review published in 2003.

OBJECTIVES

To update the evidence on the safety and effectiveness of fast-track cardiac care compared to conventional (not fast-track) care in adult patients undergoing cardiac surgery.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2012, Issue 3), MEDLINE (January 1966 to April 2012), EMBASE (January 1980 to April 2012), CINAHL (January 1982 to April 2012), and ISI Web of Science (January 2003 to April 2012). We searched reference lists of articles and contacted experts in the field.

SELECTION CRITERIA

All randomized controlled trials of adult cardiac surgical patients (coronary artery bypass grafts, aortic valve replacement, mitral valve replacement) that compared fast-track cardiac care and conventional (not fast-track) care groups were included. We focused on the following fast-track interventions that were designed for early extubation after surgery, administration of low-dose opioid based general anaesthesia during cardiac surgery and the use of a time-directed extubation protocol after surgery. The primary outcome was the risk of mortality. Secondary outcomes included postoperative complications, reintubation within 24 hours of surgery, time to extubation, length of stay in the intensive care unit and in the hospital, quality of life after surgery and hospital costs.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted the data. Study authors were contacted for additional information. We used a random-effects model and reported relative risk (RR), mean difference (MD) and 95% confidence intervals (95% CI).

MAIN RESULTS

Twenty-five trials involving 4118 patients were included in the review. There were two studies with a low risk of bias and nine studies with a high risk of bias. There were no differences in the risk of mortality within the first year after surgery between low-dose versus high-dose opioid based general anaesthesia groups (RR 0.58, 95% CI 0.28 to 1.18) and between early extubation protocol versus usual care groups (RR 0.84, 95% CI 0.40 to 1.75).There were no significant differences between low-dose versus high-dose opioid based anaesthesia groups for postoperative complications: myocardial infarction (RR 0.98, 95% CI 0.48 to 1.99), reintubation (RR 1.77, 95% CI 0.38 to 8.27), acute renal failure (RR 1.19, 95% CI 0.33 to 4.33), major bleeding (RR 0.48, 95% CI 0.16 to 1.44), and stroke (RR 1.17, 95% CI 0.36 to 3.78). Compared to the usual care, there were no significant differences in the risk of postoperative complications associated with early extubation: myocardial infarction (RR 0.94, 95% CI 0.55 to 1.60), reintubation (RR 1.91, 95% CI 0.90 to 4.07), acute renal failure (RR 0.77, 95% CI 0.19 to 3.10), major bleeding (RR 0.80, 95% CI 0.45 to 1.44), stroke (RR 0.87, 95% CI 0.31 to 2.46), major sepsis (RR 1.25, 95% CI 0.08 to 19.75) and wound infection (RR 0.67, 95% CI 0.25 to 1.83).Although there were high levels of heterogeneity, both low-dose opioid anaesthesia and the use of time-directed extubation protocols were associated with reductions in the time to extubation (3.0 to 10.5 hours) and in the length of stay in the intensive care unit (0.4 to 8.7 hours). However, these fast-track care interventions were not associated with reductions in the total length of stay in hospital. One high quality cost-effectiveness analysis included in a randomized controlled trial showed that early extubation was likely to be cost-effective.

AUTHORS' CONCLUSIONS

The use of low-dose opioid based general anaesthesia and time-directed protocols for fast-track interventions have similar risks of mortality and major postoperative complications to conventional (not fast-track) care, and therefore appear to be safe in patients considered to be at low to moderate risk. These fast-track interventions reduced the time to extubation and shortened the length of stay in the intensive care unit, but did not reduce the length of stay in the hospital.

Modifiable and nonmodifiable risk factors for postoperative delirium after cardiac surgery with cardiopulmonary bypass

OBJECTIVES

Postoperative delirium after cardiac surgery is associated with increased morbidity and mortality as well as prolonged stay in both the intensive care unit and the hospital. The authors sought to identify modifiable risk factors associated with the development of postoperative delirium in elderly patients after elective cardiac surgery in order to be able to design follow-up studies aimed at the prevention of delirium by optimizing perioperative management.

DESIGN

A post hoc analysis of data from patients enrolled in a randomized controlled trial was performed.

SETTING

A single university hospital.

PARTICIPANTS

One hundred thirteen patients aged 65 or older undergoing elective cardiac surgery with cardiopulmonary bypass.

INTERVENTIONS

None. MEASUREMENTS AND MAINS RESULTS: Screening for delirium was performed using the Confusion Assessment Method (CAM) on the first 6 postoperative days. A multivariable logistic regression model was developed to identify significant risk factors and to control for confounders. Delirium developed in 35 of 113 patients (30%). The multivariable model showed the maximum value of C-reactive protein measured postoperatively, the dose of fentanyl per kilogram of body weight administered intraoperatively, and the duration of mechanical ventilation to be independently associated with delirium.

CONCLUSIONS

In this post hoc analysis, larger doses of fentanyl administered intraoperatively and longer duration of mechanical ventilation were associated with postoperative delirium in the elderly after cardiac surgery. Prospective randomized trials should be performed to test the hypotheses that a reduced dose of fentanyl administered intraoperatively, the use of a different opioid, or weaning protocols aimed at early extubation prevent delirium in these patients.

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.

The sensitivity and specificity of three common statistical rules for the classification of post-operative cognitive dysfunction following coronary artery bypass graft surgery

BACKGROUND

The application of statistical rules to determine post-operative cognitive dysfunction (POCD) has varied, and partially explains the wide range of reported incidences of POCD in the literature. The current study assessed the sensitivity and specificity of three commonly used statistical rules in a sample of coronary artery bypass graft (CABG) patients and healthy non-surgical controls.

METHODS

Two hundred and four CABG patients [mean age, 68.8 years; standard deviation (SD), 7.0 years] completed neuropsychological assessment pre-operatively (baseline) and 1 week and 3 months post-operatively. Ninety age- and gender-matched non-surgical controls (mean age, 67.8 years; SD, 7.9 years) completed the same tasks at the same time points. POCD was determined in each group using three rules: the 1SD decline on two or more tasks; the 20% decline on 20% of tasks rule; and a modified reliable change index.

RESULTS

The modified reliable change index demonstrated the greatest combination of sensitivity and specificity. The 20% decline on 20% of tasks rule detected the largest incidence of impairment in the CABG group, but showed large incidences of false positive classifications in the control group. The 1SD rule detected the lowest incidence of POCD in the CABG group, but detected a larger incidence of impairment in the control group.

CONCLUSIONS

The use of the modified reliable change index is recommended, given the sensitivity to change it displayed and the low rates of false positive classification in the control sample. The use of control groups in future research is also recommended.

Short-stay intensive care after coronary artery bypass surgery: Randomized clinical trial on safety and cost-effectiveness*

OBJECTIVE

To evaluate the safety and cost-effectiveness of short-stay intensive care (SSIC) treatment for low-risk coronary artery bypass patients.

DESIGN

Randomized clinical equivalence trial.

SETTING

University Hospital Maastricht, the Netherlands.

PATIENTS

Low-risk coronary artery bypass patients.

INTERVENTIONS

A total of 600 patients were randomly assigned to undergo either SSIC treatment (8 hrs of intensive care treatment) or control treatment (care as usual, overnight intensive care treatment).

MEASUREMENTS

The primary outcome measures were intensive care readmissions and total hospital stay. The secondary outcome measures were total hospital costs, quality of life, postoperative morbidity, and mortality. Hospital costs consisted of the cost of hospital admission or admissions and outpatient costs.

MAIN RESULTS

The difference in intensive care readmission between the two groups of 1.13% was very small and not significantly different (p = .241; 95% confidence interval, -0.9% to 2.9%). The total hospital stay (p = .807; 95% confidence interval, 1.2 to -0.4) and postoperative morbidity were comparable between the groups. The SSIC group's quality of life improved more compared with the control group's quality of life (p = .0238; 95% confidence interval, 0.0012 to 0.0464). The total hospital costs for SSIC were significantly lower (95% confidence interval, -1,581 to -174) compared with those for the control group (4,625 and 5,441, respectively). The estimated incremental cost-effectiveness ratio (cost/delta quality-adjusted life months) thus showed the dominance of SSIC. Bootstrap and sensitivity analyses confirm the robustness of the study findings.

CONCLUSIONS

Compared with usual care, SSIC is a safe and cost-effective approach. SSIC can be considered as an alternative for conventional postoperative intensive care treatment for low-risk coronary artery bypass graft patients.

Statistical and conceptual issues in defining post-operative cognitive dysfunction

The occurrence of post-operative cognitive dysfunction is a distressing complication following surgery. In an effort to gain a more complete understanding of patients' cognitive recovery following surgical procedures common neuropsychological assessment tools have been adopted in a repeated measures design. It is widely regarded that this represents the most comprehensive method of determining cognitive status in this population but it has resulted in a number of statistical and conceptual difficulties in attempting to infer significant change. The current paper outlines these core difficulties and provides some potential methods to overcome these.

Opening of a new postanesthesia care unit: impact on critical care utilization and complications following major vascular and thoracic surgery

STUDY OBJECTIVES

To assess the impact of a new postanesthesia care unit (PACU) on intensive care unit (ICU) utilization, hospital length of stay, and complications following major noncardiac surgery.

DESIGN

Observational study.

SETTING

University hospital.

PATIENTS AND MEASUREMENTS

From 1992 to 1999, 915 patients underwent either abdominal aortic reconstruction (n = 448) or lung resection for cancer (n = 467). Demographic, clinical, surgical, and anesthetic data, as well as perioperative complications, were abstracted from two institutional databases.

INTERVENTIONS

Patients were divided in two study periods, before and after the opening of a new PACU (period 1992-1995 and period 1996-1999).

MAIN RESULTS

Utilization of ICU decreased from 35% to 16% for vascular patients and from 57% to less than 4% for thoracic patients during the second period. Readmission to the ICU, perioperative mortality, and respiratory complications were comparable between the two periods. Patients with congestive heart failure, chronic obstructive pulmonary disease, or renal insufficiency were more likely to be admitted to the ICU than the PACU. Following vascular surgery the frequency of cardiac complications decreased from 10.6% in 1992-1995 to 5.2% in 1996-1999 (p < 0.005), as well as the need for postoperative mechanical ventilation (25% vs. 12%; P < 0.05).

CONCLUSIONS

Increased availability of PACU beds resulted in reduced utilization of ICU resources without compromising patient care after major noncardiac surgery.

Trials comparing early vs late extubation following cardiovascular surgery

We identified 10 randomized trials that compared alternative management approaches to patient care during and following cardiovascular surgery. One overall strategy involved a modification of anesthesia, in particular, a reduction in the dosage of fentanyl and benzodiazepine or the substitution of fentanyl for propofol (five randomized controlled trials [RCTs]). Pooled results show a shorter duration of ventilation (7 h) and a shorter duration of hospital stay (approximately 1 day) associated with lower anesthetic doses. The second strategy involved early vs late extubation once patients were admitted to the ICU (five RCTs). Pooled results show a shorter duration of ventilation (13 h) and a shorter duration of ICU stay (half a day) associated with early extubation. An additional 8 nonrandomized trials had findings that were consistent with the 10 RCTs. Reintubation, complications, and mortality rates were too low to draw conclusions about these outcomes. Overall, these studies indicate that anesthetic, sedation, and early-extubation strategies in selected cardiac surgery patients are associated with a shorter duration of mechanical ventilation and shorter lengths of ICU and hospital stays.