Propofol-based versus fentanyl-isoflurane-based anesthesia for cardiac surgery

Comparison Between the Protective Effect of Isoflurane and Propofol on Myocardium During Coronary Artery Bypass Grafting: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

Intravenous non-volatile anaesthetics like propofol are commonly used in cardiac surgeries across several countries. Volatile anaesthetics like isoflurane may help in protecting the myocardium and minimize ischaemia-reperfusion injury. Hence, we did this review to compare the cardioprotective effect of isoflurane and propofol among patients undergoing coronary artery bypass grafting (CABG).

METHODS

We conducted a search in the databases Medical Literature Analysis and Retrieval System Online (or MEDLINE), Embase, PubMed Central®, ScienceDirect, Google Scholar, and Cochrane Library from inception until April 2021. We carried out a meta-analysis with random-effects model and reported pooled risk ratio (RR) or standardized mean difference (SMD) with 95% confidence interval (CI) depending on the type of outcome.

RESULTS

We analysed 13 studies including 808 participants. Almost all were low-quality studies. For cardiac index, the pooled SMD was 0.14 (95% CI: -0.22 to 0.50); for cardiac troponin I, pooled SMD was 0.10 (95% CI: -0.28 to 0.48). For mortality, the RR was 3.00 (95% CI: 0.32 to 28.43); for MI, pooled RR was 1.58 (95% CI: 0.59 to 4.20); and for inotropic drug use, pooled RR was 1.04 (95% CI: 0.90 to 1.21). For length of intensive care unit stay, the pooled SMD was 0.13 (95% CI: -0.29 to 0.55), while pooled SMD for mechanical ventilation time was -0.02 (95% CI: -0.54 to 0.51).

CONCLUSION

Isoflurane did not have significant cardioprotective effect compared to propofol following CABG. Hence, the anaesthetists need to check some viable alternatives to manage these patients and reduce the rate of postoperative complications.

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.

Volatile Anesthetics versus Propofol for Cardiac Surgery with Cardiopulmonary Bypass

Background

The aim of this systematic review and meta-analysis was to assess the effect of anesthesia maintenance with volatile agents compared with propofol on both short- and long-term mortality (primary outcomes) and major clinical events in adults undergoing cardiac surgery with cardiopulmonary bypass.

Methods

Randomized clinical trials on the effects of current volatile anesthetics versus propofol in adults undergoing cardiac surgery with cardiopulmonary bypass were searched (1965 to September 30, 2019) in PubMed, the Cochrane Library, and article reference lists. A random effect model on standardized mean difference for continuous outcomes and odds ratio for dichotomous outcomes were used to meta-analyze data.

Results

In total, 37 full-text articles (42 studies, 8,197 participants) were included. The class of volatile anesthetics compared with propofol was associated with lower 1-yr mortality (5.5 vs. 6.8%; odds ratio, 0.76 [95% CI, 0.60 to 0.96]; P = 0.023), myocardial infarction (odds ratio, 0.60 [95% CI, 0.39 to 0.92]; P = 0.023), cardiac troponin release (standardized mean difference, −0.39 [95% CI, −0.59 to −0.18], P = 0.0002), need for inotropic medications (odds ratio, 0.40 [95% CI, 0.24 to 0.67]; P = 0.0004), extubation time (standardized mean difference, −0.35 [95% CI, −0.68 to −0.02]; P = 0.038), and with higher cardiac index/output (standardized mean difference, 0.70 [95% CI, 0.37 to 1.04]; P < 0.0001). The class of volatile anesthetics was not associated with changes in short-term mortality (1.63 vs. 1.65%; odds ratio, 1.04 [95% CI, 0.73 to 1.49]; P = 0.820) and acute kidney injury (odds ratio, 1.25 [95% CI, 0.77 to 2.03]; P = 0.358).

Conclusions

In adults undergoing cardiac surgery with cardiopulmonary bypass, the class of volatile anesthetics was superior to propofol with regard to long-term mortality, as well as to many secondary outcomes indicating myocardial protection.

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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.

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.

Is I-gel airway a better option to endotracheal tube airway for sevoflurane-fentanyl anesthesia during cardiac surgery?

BACKGROUND

Anesthetists used lower doses of fentanyl, successfully with hemodynamic control by titrating volatile anesthetic agents or vasodilators for fast-tracking in cardiac surgery.

HYPOTHESIS

Lower total doses of anesthetics and fentanyl could be required with hemodynamic control by use of supraglottic devices than endotracheal tube (ETT) and helps in fast-tracking.

DESIGN

A prospective randomized observational clinical trial study.

AIMS

The authors compared the utility of I-gel airway with a conventional ETT during the induction and maintenance of anesthesia with sevoflurane and fentanyl in adults undergoing cardiac surgery.

PATIENTS AND METHODS

A total of 49 adult patients underwent cardiac surgery were randomized into two groups according to the airway management: I-gel group (n = 23) and ETT group (n = 26). Doses of fentanyl and hemodynamic parameters (heart rate [HR], mean arterial pressure [MAP] central venous pressure [CVP], pulmonary artery pressure [PAP], and pulmonary capillary wedge pressure [PCWP]) were recorded preoperative, 5 min following tracheal intubation or I-gel airway insertion, after skin incision, after stenotomy, and after weaning off bypass.

RESULTS

None of the patients in the I-gel group required additional doses of fentanyl during the I-gel insertion, compared with 74% of the patients during laryngoscopy and endotracheal insertion in the ETT group, for an average total dose of 22.6 ± 0.6 μg/kg. The MAP and HR did not significantly differ from the baseline values at any point of measurement in either group. Furthermore, CVP, PAP, and PCWP measured during the procedure were significantly lower in I-gel group than ETT group. Extubation required more amount of time in ETT than I- gel group.

CONCLUSION

The I-gel airway is well-tolerated by adult patients undergoing cardiac surgery, and requires lower total doses of anesthetics than endotracheal intubation with hemodynamic control and helps in fast-tracking.

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.

The effect of isoflurane on survival and myocardial infarction: a meta-analysis of randomized controlled studies

OBJECTIVE

The aim of this meta-analysis was to investigate the cardioprotective properties of isoflurane versus any comparator in terms of the rate of myocardial infarction and all-cause mortality.

DESIGN

Pertinent studies were searched independently in Biomed, Central, PubMed, Embase, and the Cochrane Central Register of clinical trials. The primary endpoint was mortality at the longest follow-up available.

SETTING

A hospital.

PARTICIPANTS

Randomized controlled trials.

INTERVENTION

A meta-analysis of 37 trials.

MEASUREMENTS AND MAIN RESULTS

The 37 included trials randomized 3,539 patients in cardiac (16 studies) and in noncardiac surgery (21 studies) with noninhalation comparators in 55% of trials. The overall analysis showed no difference in mortality between the isoflurane and control groups (16/1,602 [1.0%] v 23/1,937 [1.2%], odds ratios (OR) = 0.76 [0.39-1.47], p = 0.4 with 37 studies included) and no difference in the rate of myocardial infarction (3/1,312 [0.2%] v 1/1,532 [0.07%], OR = 2.03 [0.27-15.49], p = 0.5 with 30 studies included). Mortality was reduced in the isoflurane group when only studies with a low risk of bias were included in the analyses (0/540 [0%] v 5/703 [0.7%] in the control arm, OR = 0.13 [0.02-0.76], p = 0.02) with 4 cardiac and 6 noncardiac trials included and 5 noninhalation and 5 inhalation agents as the comparator. A trend was noted when a subanalysis was performed with propofol as a comparator (1/544 [0.2%] v 6/546 [1.1%], p = 0.05, with 16 studies included).

CONCLUSIONS

Isoflurane reduced mortality in high-quality studies and showed a trend toward a reduction in mortality when it was compared with propofol. No differences in the rates of overall mortality and myocardial infarction were noted.

Does fast-track treatment lead to a decrease of intensive care unit and hospital length of stay in coronary artery bypass patients? A meta-regression of randomized clinical trials*

OBJECTIVE

Evaluation of randomized, controlled clinical trials studying fast-track treatment in low-risk coronary artery bypass grafting patients.

DESIGN

Meta-regression.

PATIENTS

Low-risk coronary artery bypass grafting patients.

INTERVENTIONS

Fast-track treatments including (high or low) anesthetic dose, normothermia vs. hypothermia, and extubation protocol (within or after 8 hrs).

MEASUREMENTS

Number of hours of intensive care unit stay, number of days of hospital stay, prevalence of myocardial infarction, and death. Furthermore, quality of life and cost evaluations were evaluated. The epidemiologic and economic qualities of the different trials were also assessed.

MAIN RESULTS

A total of 27 studies evaluating fast-track treatment were identified, of which 12 studies were with major and 15 were without major differences in extubation protocol or anesthetic treatment or both. The use of an early extubation protocol (p=.000) but not the use of a low anesthetic dose (p=.394) or normothermic temperature management (p=.552) resulted in a decrease of the total intensive care unit stay of low-risk coronary artery bypass grafting patients. Early extubation was found to be an important determinant of the total hospital stay for these patients. An influence of the type of fast-track treatment on mortality or the prevalence of postoperative myocardial infarction was not observed. In general, the epidemiologic and economic qualities of included studies were moderate.

CONCLUSIONS

Although fast-track anesthetics and normothermic temperature management facilitate early extubation, the introduction of an early extubation protocol seems essential to decrease intensive care unit and hospital stay in low-risk coronary artery bypass grafting patients.

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.

Time to tracheal extubation after coronary artery surgery with isoflurane, sevoflurane, or target-controlled propofol anesthesia: A prospective, randomized, controlled trial

OBJECTIVES

To determine if anesthesia with sevoflurane or target-controlled propofol reduced the time to tracheal extubation after coronary artery bypass graft surgery compared with isoflurane anesthesia.

DESIGN

A 3-arm (isoflurane, sevoflurane, or propofol), randomized, controlled trial with patients and intensive care staff blinded to the drug allocation.

SETTING

A single, tertiary referral hospital affiliated with the University of Melbourne.

PARTICIPANTS

Three hundred sixty elective coronary artery surgery patients.

INTERVENTIONS

Patients received either isoflurane (control group, 0.5%-2% end-tidal concentration), sevoflurane (1%-4% end-tidal concentration), or target-controlled infusion of propofol (1-8 microg/mL plasma target concentration) as part of a balanced, standardized anesthetic technique including 15 microg/kg of fentanyl.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was time to tracheal extubation. The median time to tracheal extubation for the propofol group was 10.25 hours (interquartile range [IQR] 8.08-12.75), the sevoflurane group 9.17 hours (IQR 6.25-11.25), and the isoflurane group 7.67 hours (IQR 6.25-9.42). Intraoperatively, the propofol group required less vasopressor (p = 0.002) and more vasodilator therapy (nitroglycerin p = 0.01, nitroprusside p = 0.002). There was no difference among the groups in time to intensive care unit discharge.

CONCLUSIONS

The median time to tracheal extubation was significantly longer for the target-controlled propofol group. A significantly greater number in this group required the use of a vasodilator to control intraoperative hypertension.

Automatic “Respirator/Weaning” with Adaptive Support Ventilation: The Effect on Duration of Endotracheal Intubation and Patient Management

Adaptive support ventilation (ASV) provides an automatic adaptation of the ventilator settings to patient's passive and active respiratory mechanics. In a randomized controlled study, we evaluated automatic respiratory weaning in ASV for early tracheal extubation after cardiac surgery. Eligible patients were assigned to either an ASV protocol or a standard one consisting of synchronized intermittent ventilation followed by pressure support. Eighteen patients completed the ASV protocol, and 16 completed the standard one. There were no differences between groups in perioperative characteristics, lengths of tracheal intubation and intensive care unit stay, and ventilatory variables, except less peak inspiratory pressure during the initial phase in ASV (17.5 +/- 0.8 versus 22.2 +/- 0.8 cm H(2)O; P < 0.01). ASV patients required fewer ventilatory settings manipulations (2.4 +/- 0.7 versus 4.0 +/- 0.8 manipulations per patient; P < 0.05) and endured less high-inspiratory pressure alarms (0.7 +/- 2.4 versus 2.9 +/- 3.0; P < 0.05). These results suggest that in this specific population of patients, automation of postoperative ventilation with ASV resulted in an outcome similar to the control group. The internal logic of the new device resulted in less manipulation of the setting and alarms that could simplify respiratory management.

IMPLICATIONS

Adaptive support ventilation (ASV), a ventilatory mode providing automatic adjustment of the settings was compared with standard management for rapid tracheal extubation after cardiac surgery. The two approaches were equal in terms of outcome. In ASV, we observed fewer ventilator settings manipulations and a smaller amount of alarms, suggesting that this automatic mode may simplify postoperative respiratory management without delaying extubation.

Clinical experience with adaptive support ventilation for fast-track cardiac surgery

OBJECTIVE

To evaluate adaptive support ventilation (ASV), an automatic microprocessor-controlled mode of mechanical ventilation, for the initial ventilatory management in consecutive patients eligible for early extubation after cardiac surgery.

DESIGN

Prospective observational study.

SETTING

Nonuniversity cardiac center.

PARTICIPANTS

One hundred fifty-five consecutive patients eligible for early tracheal extubation after cardiac surgery.

INTERVENTIONS

On intensive care unit arrival, patients were ventilated by adaptive support ventilation. This mode provided an automatic selection of initial ventilatory parameters and a continuous adaptation to patient's respiratory activity, guaranteeing that a preset minute ventilation was delivered. Once the patients had recovered sustained spontaneous ventilation, the ventilator was switched manually to pressure support for the terminal part of respiratory weaning followed by extubation.

MEASUREMENTS AND MAIN RESULTS

In adaptive support ventilation, all patients could be ventilated satisfactorily except 1; tidal volume was 8.7 +/- 1.4 mL/kg of ideal body weight (mean +/- SD), plateau pressure was 20.3 +/- 3.9 cmH(2)O, and arterial blood gas measurements were satisfactory. One hundred thirty-four patients (86%) were extubated within 6 hours, and intubation time was 3.6 (2.53-4.83) hours (median, [quartiles]). No reintubation because of respiratory failure was required. Adaptive support ventilation was considered easy to use by both the nurses and physicians.

CONCLUSIONS

Adaptive support ventilation was used in a group of 155 consecutive patients after fast-track cardiac surgery. This ventilation mode was safe, easy to apply, and allowed rapid extubation in suitable patients. ASV may facilitate postoperative respiratory management.

Cost comparisons of pharmacological strategies in open-heart surgery

Open-heart surgery (OHS) is performed to bypass occluded arteries, replace malfunctioning cardiac valves or correct congenital abnormalities. The average cost of OHS varies from $US25 057-$US79 795 (1997 values). The objective of this paper was to review economic studies of pharmacological strategies in open-heart surgery. Pharmacological strategies studied include the prevention of postoperative complications such as atrial fibrillation (AF), bleeding and infection. Modifications in anaesthetic technique have been attempted by using agents that promote early extubation. In addition, strategies for postoperative management of sedation, analgesia and AF and use of neuromuscular blockers have also been compared. The majority of studies in this area have been cost analyses with few cost-effectiveness studies performed. Prophylaxis against AF with amiodarone is associated with a reduction in AF and was cost-neutral compared with placebo. Compared with placebo, prevention of bleeding with antifibrinolytics reduces transfusion costs. In direct comparative studies, lysine analogues, due to lower drug acquisition costs, offset transfusion costs to a greater extent than aprotinin. However, safety concerns with the lysine analogues remain. Erythropoietin decreases transfusion requirements and is cost effective compared with no intervention when the cost of postoperative bacterial complications is included. First- and second-generation cephalosporins prevent postoperative infections. Based on drug acquisition cost, the first-generation agents are less expensive although when administration costs are included, both classes have similar costs. Modifications in anaesthetic technique with short-acting anaesthetic agents, results in higher drug costs although nursing and total hospital costs are typically reduced. For neuromuscular blockers, drug acquisition costs are lowest with pancuronium but administration costs and the cost of adverse events have not been included in existing analyses. Midazolam provides an equivalent level of postoperative sedation to propofol but the acquisition cost is lower. The combined use of propofol and midazolam warrants further investigation, as its use is associated with lower sedative agent costs compared with either agent alone. There is limited data on the economics of postoperative analgesia and the management of AF. As the majority of studies to date are partial cost analyses, additional studies that include length of stay and other hospitalisation data are warranted. In future, cost-effectiveness and cost-utility studies, which incorporate quality of life and the cost of adverse effects and other longer term costs, should be undertaken.

Cost, outcome, and functional status in octogenarians and septuagenarians after cardiac surgery

STUDY OBJECTIVES

To evaluate cost, outcome, and functional status of octogenarians and septuagenarians after cardiac surgery.

DESIGN

Observational case control study. Retrospective analysis of hospital cost and outcome. Prospective analysis of functional status at 1 to 2 years.

PATIENTS

One hundred three consecutive octogenarians and 103 randomly selected septuagenarians who underwent cardiac surgery.

SETTING

A university-affiliated tertiary care center.

MEASUREMENTS AND RESULTS

Compared to septuagenarians, octogenarians were more likely to be widowed (p < or = 0.001) and to have had preoperative strokes (p < or = 0.05) but were less likely to have diabetes mellitus (p < or = 0.001). They were less likely to have undergone mitral valve surgery (p < or = 0.01) but were more likely to have undergone coronary artery bypass graft surgery without cardiopulmonary bypass (p < or = 0.001). The hospital mortality rate was 6% in the younger group and 9% in the older group (odds ratio, 1.5; 95% confidence interval [CI], 0.5 to 4.5; p > 0.05). In patients undergoing isolated CABG, the mortality rate was 1.4% in the septuagenarians and 8.2% in the octogenarians (odds ratio, 6.2; 95% CI, 0.7 to 52.7; p = 0.12). Despite similar ICU, postoperative, and total lengths of stay, the median hospital direct variable cost was 35% higher for the octogenarians. At late follow-up, octogenarians had lower levels of physical functioning and general health but otherwise had levels of function that were similar to those of septuagenarians.

CONCLUSION

Cardiac surgery can be performed in the elderly with good hospital and late functional results, but at a higher hospital cost than that for younger patients.

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.

A comparison of fentanyl, sufentanil, and remifentanil for fast-track cardiac anesthesia

Cardiac surgery is estimated to cost $27 billion annually in the United States. In an attempt to decrease the costs of cardiac surgery, fast-track programs have become popular. The purpose of this study was to compare the effects of three different opioid techniques for cardiac surgery on postoperative pain, time to extubation, time to intensive care unit discharge, time to hospital discharge, and cost. Ninety adult patients undergoing cardiac surgery were randomized to a fentanyl-based, sufentanil-based, or remifentanil-based anesthetic. Postoperative pain was measured at 30 min after extubation and at 6:30 AM on the first postoperative day. Pain scores at both times were similar in all three groups (P > 0.05). Median ventilator times of 167, 285, and 234 min (P > 0.05), intensive care unit stays of 18.8, 19.8, and 21.5 h (P > 0.05), and hospital stays of 5, 5, and 5 days (P > 0.05) for the Fentanyl, Sufentanil, and Remifentanil groups did not differ. Three patients needed to be tracheally reintubated: two in the Sufentanil group and one in the Fentanyl group. Median anesthetic costs were largest in the Remifentanil group ($140.54 [$113.54-$179.29]) and smallest in the Fentanyl group ($43.33 [$39.36-$56.48]) (P < or = 0.01), but hospital costs were similar in the three groups: $7841 (Fentanyl), $5943 (Sufentanil), and $6286 (Remifentanil) (P > 0.05). We conclude that the more expensive but shorter-acting opioids, sufentanil and remifentanil, produced equally rapid extubation, similar stays, and similar costs to fentanyl, indicating that any of these opioids can be recommended for fast-track cardiac surgery.

IMPLICATIONS

To conserve resources for cardiac surgery, fentanyl-, sufentanil-, and remifentanil-based anesthetics were compared for duration of mechanical ventilation, intensive care unit length of stay, hospital length of stay, and cost. The shorter-acting anesthetics, sufentanil and remifentanil, produced equally rapid extubation, similar stays, and similar costs to fentanyl; thus, any of these opioids can be recommended for fast-track cardiac surgery.

Effects of body size on operative, intermediate, and long-term outcomes after coronary artery bypass operation

BACKGROUND

To investigate the role of body size, if any, on operative and longer term outcomes following coronary artery surgery.

METHODS

A total of 3,560 consecutive patients undergoing coronary artery bypass grafting from 1991 to 1997, including 2,401 (67%) males and a mean +/- SD age of 63 +/- 10 years were ranked based on their body mass index (BMI). The association in these patients of preoperative, long-term, and economic data with variations in BMI were studied using regression analyses. Long-term survival was studied using 5-year Kaplan-Meier survival analysis.

RESULTS

Operative mortality, myocardial infarction, cerebrovascular accidents, blood transfusions, and length of hospital stay were all increased in the smallest patients (BMI < or = 24 kg/m2). Obesity did not increase adverse operative outcomes except for a greater rate of sternal wound infections occurring with increasing severity of obesity. Direct variable costs were lowest in patients clustered around normal BMI, with cost increasing similarly at low and high extremes. This effect was correlated with similar BMI effects on ventilatory and intensive care requirements. Excluding operative mortality, 5-year survival trends were similarly worse for the smallest (BMI < or = 24) and most severely obese (BMI > 34) patients. Mild obesity (BMI > or = 30 to BMI < 34) did not affect long-term survival.

CONCLUSIONS

Among study patients, immediate operative outcomes were adversely affected by small body size, which reflected older age (66 +/- 10 years) and an exaggerated adverse impact of cardiopulmonary bypass. Younger age and smaller effects of cardiopulmonary bypass lead to better operative outcomes in the obese. Long-term outcomes were, however, suboptimal in severely obese patients although that group was the youngest (60 +/- 10 years). In addition to their large body habitus, other factors, including substantial prevalence of diabetes, insulin dependence and hypertension, probably played a significant role in the poor long-term outcome in the severely obese.