Postoperative pulmonary function in coronary artery bypass graft surgery patients undergoing early tracheal extubation: a comparison between short-term mechanical ventilation and early extubation

Comprehensive Strategies for Preoperative Pulmonary Risk Evaluation and Management

Postoperative pulmonary complications (PPCs) significantly increase morbidity and mortality in surgical patients, particularly those with pulmonary conditions. PPC incidence varies widely, influenced by factors such as surgery type, patient age, smoking status, and comorbid conditions, including chronic obstructive pulmonary disease (COPD) and congestive heart failure. While preoperative pulmonary function tests and chest radiographs are crucial for lung resection surgery, their use should be judiciously tailored to individual risk profiles. Effective risk stratification models, such as the American Society of Anesthesiologists classification, Arozullah respiratory failure index, Gupta Calculators, and Assess Respiratory Risk in Surgical Patients in Catalonia (ARISCAT) model, play a key role in predicting PPCs. Key strategies to diminish PPCs include preoperative optimization of respiratory conditions, smoking cessation, and respiratory rehabilitation. In patients with COPD and asthma, it is crucial to maintain optimal disease control through inhaled therapies, systemic corticosteroids, and tailored preoperative respiratory exercises. Anemia and hypoalbuminemia are significant predictors of PPCs and require meticulous management. The choice and duration of anesthesia also notably influence PPC risk, with regional anesthesia being preferable to general anesthesia when possible. Comprehensive preoperative evaluations and tailored interventions are essential for enhancing surgical outcomes and reducing PPC incidence. Additional studies involving domestic patients are necessary to refine national guidelines for managing those at risk of PPCs.

Effects of small-dose S-ketamine on anesthesia-induced atelectasis in patients undergoing general anesthesia accessed by lung ultrasound: study protocol for a randomized, double-blinded controlled trial

BACKGROUND

Atelectasis after anesthesia induction in most patients undergoing general anesthesia may lead to postoperative pulmonary complications (PPCs) and affect postoperative outcomes. However, there is still no existing effective method used for the prevention of perioperative atelectasis. S-ketamine may prevent atelectasis due to airway smooth muscle relaxation and anti-inflammatory effects. Lung ultrasound is a portable and reliable bedside imaging technology for diagnosing anesthesia-induced atelectasis. The primary objective of this study is to assess whether a small dose of S-ketamine can reduce the incidence of atelectasis after intubation, and further investigate the effects of preventing the early formation of perioperative atelectasis and PPCs.

METHODS

This is a single-institution, prospective, randomized controlled, parallel grouping, and double-blind study. From October 2020 to March 2022, 100 patients (18-60 years old) scheduled for elective surgery will be recruited from Beijing Tiantan Hospital, Capital Medical University, and randomly assigned to the S-ketamine group (group 1) and the normal saline group (group 2) at a ratio of 1:1. The label-masked agents will be administered 5 min before induction, and all patients will undergo a standardized general anesthesia protocol. Related data will be collected at three time points: after radial artery puncture (T1), 15 min after tracheal intubation (T2), and before extubation (T3). The primary outcome will be the total lung ultrasound scores (LUS) at T2. Secondary outcomes will include LUS in six chest regions at T2, total LUS at T3, arterial blood gas analysis results (PaCO2, PaO2) and PaO2/FiO2 at T2 and T3, and plateau pressure (Pplat) and dynamic lung compliance (Cdyn) at T2 and T3. The incidence of postoperative complications associated with S-ketamine and PPCs at 2 h and 24 h after surgery will be recorded.

DISCUSSION

This trial aims to explore whether a simple and feasible application of S-ketamine before the induction of general anesthesia can prevent atelectasis. The results of this study may provide new ideas and direct clinical evidence for the prevention and treatment of perioperative pulmonary complications during anesthesia.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04745286. Registered on February 9, 2021.

On-table Extubation After Minimally Invasive Cardiac Surgery: A Retrospective Observational Pilot Study

OBJECTIVE

To assess the safety of "on-table" extubation after minimally-invasive heart valve surgery.

DESIGN

A single-center retrospective observational study.

SETTING

At a tertiary referral academic hospital.

PARTICIPANTS

Patients who underwent nonemergent isolated heart valve surgery through a minithoracotomy approach between January 2016 and August 2021.

INTERVENTION

All patients were treated by 1 of the 6 cardiac anesthesiologists of the hospital. Only some of them practiced "on-table" extubation, and the outcome of patients extubated "on-table" was compared to those extubated in the intensive care unit (ICU).

MEASUREMENT AND MAIN RESULTS

The primary outcome was the occurrence of any postoperative respiratory complication during the entire hospital stay. Secondary outcomes included the use of inotropes and vasopressors, de novo atrial fibrillation, and lengths of stay in the ICU and the hospital. A total of 294 patients met inclusion criteria, of whom 186 (63%) were extubated "on-table." Cardiopulmonary bypass duration was significantly longer, and moderate intraoperative hypothermia was significantly more frequent in patients extubated in the ICU. After adjustment for these confounders and for the European System for Cardiac Operative Risk Evaluation (EuroSCORE) II using a multivariate logistic model, no association was found between the extubation strategy and postoperative pulmonary complications (adjusted odds ratio = 0.84; 95% CI = 0.40-1.77; p = 0.64). "On-table" extubation was associated with a lower risk of postoperative pneumonia and fewer vasopressors requirements.

CONCLUSION

"On-table" extubation was not associated with an increased incidence of respiratory complications. A randomized controlled trial is warranted to confirm these results and determine whether "on-table" extubation offers additional benefits.

Assessment of factors affecting short-term pulmonary functions following cardiac surgery: A prospective observational study

BACKGROUND

Pulmonary complications after cardiac surgery are very common and lead to an increased incidence of post-operative morbidity and mortality. Several factors, either modifiable or non-modifiable, may contribute to the associated unfavorable consequences related to pulmonary function. This study was aimed to investigate the degree of alteration and factors influencing pulmonary function (forced expiratory volume in one second (FEV₁) and forced vital capacity), on third, fifth, and seventh post-operative days following cardiac surgery.

METHODS

This study was executed in 71 patients who underwent on-pump cardiac surgery. Pulmonary function was assessed before surgery and on the third, fifth, and seventh post-operative days. Data including surgical details, information about risk factors, and assessment of pulmonary function were obtained.

RESULTS

The FEV₁ and forced vital capacity were significantly impaired on post-operative days 3, 5, and 7 compared to pre-operative values. The reduction in FEV₁ was 41%, 29%, and 16% and in forced vital capacity was 42%, 29%, and 19% consecutively on post-operative days 3, 5, and 7. Multivariate analysis was done to detect the factors influencing post-operative FEV₁ and forced vital capacity.

DISCUSSION

This study observed a significant impairment in FEV₁ and forced vital capacity, which did not completely recover by the seventh post-operative day. Different factors affecting post-operative FEV₁ and forced vital capacity were pre-operative FEV₁, age ≥60, less body surface area, lower pre-operative chest expansion at the axillary level, and having more duration of cardiopulmonary bypass during surgery. Presence of these factors enhances the chance of developing post-operative pulmonary 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.

Association of earlier extubation and postoperative delirium after coronary artery bypass grafting

OBJECTIVES

Earlier extubation after cardiac surgery is reported to have benefits on length of stay and complication rates, but the influence on postoperative delirium remains unclear. We sought to determine the effect of earlier extubation on delirium after coronary artery bypass grafting.

METHODS

A single-center retrospective review of consecutive isolated coronary artery bypass grafting patients from January 1, 2010, to December 31, 2015, was conducted. Baseline demographic characteristics, preoperative comorbidities, intraoperative data, and postoperative data were collected. A multivariable logistic regression was performed with analysis limited to extubation within the first 24 hours postoperatively.

RESULTS

We identified 2561 eligible patients. Delirium occurred in 13.9% (n = 357). Duration of postoperative mechanical ventilation was associated with higher delirium rates following adjustment, particularly after 12 to 24 hours (hourly odds ratio, 1.12; 95% confidence interval, 1.05-1.19; P < .001). No association was observed during the time period from 0 to 12 hours (hourly odds ratio, 1.02; 95% confidence interval, 0.99-1.06; P = .218). Major adverse events were associated with duration of ventilation after 0 to 12 hours (hourly odds ratio, 1.08; 95% confidence interval, 1.03-1.14; P < .002) but not after 12 to 24 hours (hourly odds ratio, 1.04; 95% CI, 0.96-1.14; P = .316). The overall rate of reintubation was 2.9% (n = 73).

CONCLUSIONS

Our findings suggest that delirium rates increase with lengthier postoperative ventilation times. This study provides the basis for consideration of the appropriate selection of earlier extubation to minimize delirium in patients undergoing cardiac surgery.

Impact of intrathecal morphine analgesia on the incidence of pulmonary complications after cardiac surgery: a single center propensity-matched cohort study

Background

Acute pain and systemic opioids may both negatively impact respiratory function after cardiac surgery. This study analyzes the local practice of using intrathecal morphine analgesia (ITMA) with minimal parenteral opioid administration in cardiac surgery, specifically the impact on postoperative pulmonary complications (PPCs).

Methods

Data from adult patients who underwent elective cardiac surgery between January 2002, and December 2013 in a single center were analyzed. Propensity scores estimating the likelihood of receiving ITMA were used to match (1:1) patients with ITMA and patients with intravenous analgesia (IVA). Primary outcome was PPCs, a composite endpoint including pneumonia, adult respiratory distress syndrome, and any type of acute respiratory failure. Secondary outcomes were in-hospital mortality, cardiovascular complications, and length of stay in the intensive care unit (ICU) and hospital.

Results

From a total of 1′543 patients, 920 were treated with ITMA and 623 with IVA. No adverse event consequent to the spinal puncture was reported. Propensity score matching created 557 balanced pairs. The occurrence of PPCs in patients with ITMA was 8.1% vs. 12.8% in patients with IVA (odds ratio, 0.6; 95% CI, 0.40–0.89; p = 0.012). Fewer patients with ITMA had a prolonged stay in the ICU (> 4 days; 16.5% vs. 21.2%, p = 0.047) or in the hospital (> 15 days; 25.5% vs. 31.8%. p = 0.024). In-hospital mortality and cardiovascular complications did not differ significantly between the two groups.

Conclusion

In this study involving cardiac surgical patients, ITMA was safely applied and was associated with fewer PPCs.

Electronic supplementary material

The online version of this article (doi:10.1186/s12871-017-0398-z) contains supplementary material, which is available to authorized users.

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.

Pulmonary Complications After Cardiac Surgery

Over the past two decades there has been a steady evolution in the practice of adult cardiac surgery with the introduction of “off-pump” surgery. However, respiratory complications remain a leading cause of postcardiac surgical morbidity and can prolong hospital stays and increase costs. The high incidence of pulmonary complications is in part due to the disruption of normal ventilatory function that is inherent to surgery in the thoracic region. Furthermore, patients undergoing such surgery often have underlying illnesses such as intrinsic lung disease (e.g., chronic obstructive pulmonary disease) and pulmonary dysfunction secondary to cardiac disease (e.g., congestive heart failure) that increase their susceptibility to postoperative respiratory problems. Given that many patients undergoing cardiac surgery are thus susceptiple to pulmonary complications, it is remarkable that more patients do not suffer from them during and after cardiac surgery. This is to a large degree because of advances in anesthetic, surgical and critical care that, for example, have reduced the physiological insults of surgery (e.g., better myocardial preservation techniques) and streamlined care in the immediate postoperative period (e.g., early extubation). Moreover, the development of minimally invasive surgery and nonbypass techniques are further evidence of the attempts at reducing the homeostatic disruptions of cardiac surgery. This review examines the available information on the incidences, consequences, and treatments of postcardiac surgery respiratory complications.

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.

A specialized post anaesthetic care unit improves fast-track management in cardiac surgery: a prospective randomized trial

Introduction

Fast-track treatment in cardiac surgery has become the global standard of care. We compared the efficacy and safety of a specialised post-anaesthetic care unit (PACU) to a conventional intensive care unit (ICU) in achieving defined fast-track end points in adult patients after elective cardiac surgery.

Methods

In a prospective, single-blinded, randomized study, 200 adult patients undergoing elective cardiac surgery (coronary artery bypass graft (CABG), valve surgery or combined CABG and valve surgery), were selected to receive their postoperative treatment either in the ICU (n = 100), or in the PACU (n = 100). Patients who, at the time of surgery, were in cardiogenic shock, required renal dialysis, or had an additive EuroSCORE of more than 10 were excluded from the study. The primary end points were: time to extubation (ET), and length of stay in the PACU or ICU (PACU/ICU LOS respectively). Secondary end points analysed were the incidences of: surgical re-exploration, development of haemothorax, new-onset cardiac arrhythmia, low cardiac output syndrome, need for cardiopulmonary resuscitation, stroke, acute renal failure, and death.

Results

Median time to extubation was 90 [50; 140] min in the PACU vs. 478 [305; 643] min in the ICU group (P <0.001). Median length of stay in the PACU was 3.3 [2.7; 4.0] hours vs. 17.9 [10.3; 24.9] hours in the ICU (P <0.001). Of the adverse events examined, only the incidence of new-onset cardiac arrhythmia (25 in PACU vs. 41 in ICU, P = 0.02) was statistically different between groups.

Conclusions

Treatment in a specialised PACU rather than an ICU, after elective cardiac surgery leads to earlier extubation and quicker discharge to a step-down unit, without compromising patient safety.

Trial registration

ISRCTN71768341. Registered 11 March 2014.

Off-pump coronary revascularization: A potential benefit for female patients?

Coronary artery disease is one of the leading causes of illness for both men and women. However, women are 3 times more likely to die for coronary artery disease as they are of breast cancer. There are an increasing prevalence of coronary artery disease in women and thus facing the need for surgical revascularization. It has long being accepted that women carry a high risk of coronary surgery than men. Many investigators have suggested that female itself is predictive of poor outcome after on pump coronary surgery. We thought to search the litlature to investigate whether women who undergo off-pump surgery receive any benefits compared with women undergoing on-pump surgery.

Epidural analgesia for cardiac surgery

BACKGROUND

A combination of general anaesthesia (GA) with thoracic epidural analgesia (TEA) may have a beneficial effect on clinical outcomes by reducing the risk of perioperative complications after cardiac surgery.

OBJECTIVES

The objective of this review was to determine the impact of perioperative epidural analgesia in cardiac surgery on perioperative mortality and cardiac, pulmonary or neurological morbidity. We performed a meta-analysis to compare the risk of adverse events and mortality in patients undergoing cardiac surgery under general anaesthesia with and without epidural analgesia.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2012, Issue 12) in The Cochrane Library; MEDLINE (PubMed) (1966 to November 2012); EMBASE (1989 to November 2012); CINHAL (1982 to November 2012) and the Science Citation Index (1988 to November 2012).

SELECTION CRITERIA

We included randomized controlled trials comparing outcomes in adult patients undergoing cardiac surgery with either GA alone or GA in combination with TEA.

DATA COLLECTION AND ANALYSIS

All publications found during the search were manually and independently reviewed by the two authors. We identified 5035 titles, of which 4990 studies did not satisfy the selection criteria or were duplicate publications, that were retrieved from the five different databases. We performed a full review on 45 studies, of which 31 publications met all inclusion criteria. These 31 publications reported on a total of 3047 patients, 1578 patients with GA and 1469 patients with GA plus TEA.

MAIN RESULTS

Through our search (November 2012) we have identified 5035 titles, of which 31 publications met our inclusion criteria and reported on a total of 3047 patients. Compared with GA alone, the pooled risk ratio (RR) for patients receiving GA with TEA showed an odds ratio (OR) of 0.84 (95% CI 0.33 to 2.13, 31 studies) for mortality; 0.76 (95% CI 0.49 to 1.19, 17 studies) for myocardial infarction; and 0.50 (95% CI 0.21 to 1.18, 10 studies) for stroke. The relative risks (RR) for respiratory complications and supraventricular arrhythmias were 0.68 (95% CI 0.54 to 0.86, 14 studies) and 0.65 (95% CI 0.50 to 0.86, 15 studies) respectively.

AUTHORS' CONCLUSIONS

This meta-analysis of studies, identified to 2010, showed that the use of TEA in patients undergoing coronary artery bypass graft surgery may reduce the risk of postoperative supraventricular arrhythmias and respiratory complications. There were no effects of TEA with GA on the risk of mortality, myocardial infarction or neurological complications compared with GA alone.

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.

Lung Function before and Two Days after Open-Heart Surgery

Reduced lung volumes and atelectasis are common after open-heart surgery, and pronounced restrictive lung volume impairment has been found. The aim of this study was to investigate factors influencing lung volumes on the second postoperative day. Open-heart surgery patients (n = 107, 68 yrs, 80% male) performed spirometry both before surgery and on the second postoperative day. The factors influencing postoperative lung volumes and decrease in lung volumes were investigated with univariate and multivariate analyses. Associations between pain (measured by numeric rating scale) and decrease in postoperative lung volumes were calculated with Spearman rank correlation test. Lung volumes decreased by 50% and were less than 40% of the predictive values postoperatively. Patients with BMI >25 had lower postoperative inspiratory capacity (IC) (33 ± 14% pred.) than normal-weight patients (39 ± 15% pred.), (P = 0.04). More pain during mobilisation was associated with higher decreases in postoperative lung volumes (VC: r = 0.33, P = 0.001; FEV₁: r = 0.35, P ≤ 0.0001; IC: r = 0.25, P = 0.01). Patients with high BMI are a risk group for decreased postoperative lung volumes and should therefore receive extra attention during postoperative care. As pain is related to a larger decrease in postoperative lung volumes, optimal pain relief for the patients should be identified.

Factors predicting ventilator dependence in patients with ventilator-associated pneumonia

Objectives. To determine risk factors associated with ventilator dependence in patients with ventilator-associated pneumonia (VAP). Study Design. A retrospective study was conducted at Chang Gung Memorial Hospital, Kaohsiung, from January 1, 2007 to January 31, 2008. Methods. This study evaluated 163 adult patients (aged ≥18 years). Eligibility was evaluated according to the criterion for VAP, Sequential Organ Failure Assessment (SOFA) score, Acute Physiological Assessment and Chronic Health Evaluation II (APACHE II) score. Oxygenation index, underlying comorbidities, septic shock status, previous tracheostomy status, and factors related to pneumonia were collected for analysis. Results. Of the 163 VAP patients in the study, 90 patients survived, yielding a mortality rate of 44.8%. Among the 90 surviving patients, only 36 (40%) had been weaned off ventilators at the time of discharge. Multivariate logistic regression analysis was used to identify underlying factors such as congestive cardiac failure (P = 0.009), initial high oxygenation index value (P = 0.04), increased SOFA scores (P = 0.01), and increased APACHE II scores (P = 0.02) as independent predictors of ventilator dependence. Results from the Kaplan-Meier method indicate that initial therapy with antibiotics could increase the ventilator weaning rate (log Rank test, P < 0.001). Conclusions. Preexisting cardiopulmonary function, high APACHE II and SOFA scores, and high oxygenation index were the strongest predictors of ventilator dependence. Initial empiric antibiotic treatment can improve ventilator weaning rates at the time of discharge.

Nurse-Led Preoperative Screening and Targeted Optimization of Pulmonary Dysfunction in Patients Undergoing Cardiac Surgery

Postoperative pulmonary dysfunction prolonging intensive care treatment after cardiac surgery most commonly occurs in patients with a background of pre-existing pulmonary dysfunction. However, many patients have occult dysfunction and present primarily after surgery. We describe and discuss the results of a respiratory optimization program utilizing a peak expiratory flow rate below 400 L/min as a screening test to identify patients in a nurse-directed preoperative clinic.

Atelectasis in the perioperative patient

PURPOSE OF REVIEW

To report the impact of atelectasis on perioperative outcomes. Atelectasis occurs in the dependent parts of the lungs of most patients who are anesthetized. Development of atelectasis is associated with decreased lung compliance, impairment of oxygenation, increased pulmonary vascular resistance and development of lung injury. Here, we examine the etiology, contributing factors, consequences, diagnosis and treatment of atelectasis.

RECENT FINDINGS

Atelectasis describes the state of absent air in alveoli attributable to collapse, but recent findings suggest that alveoli are filled with foam and fluid. It is now known that atelectasis plays an important role beyond abnormal gas exchange and that prevention or reversal of atelectasis in some populations of postoperative patients may improve outcome.

SUMMARY

Atelectasis in the presence of preexisting lung disease or limited cardiopulmonary reserve may have significant consequences. Increasing understanding of the underlying nature of atelectasis and its contribution to acute lung injury will improve our approach to the prevention and management of atelectasis.

Open lung ventilation improves functional residual capacity after extubation in cardiac surgery*

OBJECTIVE

After cardiac surgery, functional residual capacity (FRC) after extubation is reduced significantly. We hypothesized that ventilation according to the open lung concept (OLC) attenuates FRC reduction after extubation.

DESIGN

A prospective, single-center, randomized, controlled clinical study.

SETTING

Cardiothoracic operating room and intensive care unit of a university hospital.

PATIENTS

Sixty-nine patients scheduled for elective coronary artery bypass graft and/or valve surgery with cardiopulmonary bypass.

INTERVENTIONS

Before surgery, patients were randomly assigned to three groups: (1) conventional ventilation (CV); (2) OLC, started after arrival in the intensive care unit (late open lung); and (3) OLC, started directly after intubation (early open lung). In both OLC groups, recruitment maneuvers were applied until Pao2/Fio2 was >375 Torr (50 kPa). No recruitment maneuvers were applied in the CV group.

MEASUREMENTS AND MAIN RESULTS

FRC was measured preoperatively and 1, 3, and 5 days after extubation. Peripheral hemoglobin saturation (Spo2) was measured daily till the third day after extubation while the patient was breathing room air. Hypoxemia was defined by an Spo2 value < or =90%. Averaged over the 5 postoperative days, FRC was significantly higher in the early open lung group and tended to be higher in the late open lung group, in comparison with the CV group (mean +/- sem: CV, 1.8 +/- 0.1; late open lung,1.9 +/- 0.1; and early open lung, 2.2 +/- 0.1l). In the CV group, 37% of the patients were hypoxic on the third day after extubation, compared with none of the patients in both OLC groups.

CONCLUSIONS

After cardiac surgery, earlier application of OLC resulted in a significantly higher FRC and fewer episodes of hypoxemia than with CV after extubation.

Pulmonary Outcomes of Off-Pump vs On-Pump Coronary Artery Bypass Surgery in a Randomized Trial

STUDY OBJECTIVES

Comparison of pulmonary outcomes after off-pump coronary artery bypass (OPCAB) vs on-pump coronary artery grafting with cardiopulmonary bypass (CABG/CPB).

STUDY DESIGN

We examined preoperative and postoperative respiratory compliance, fluid balance, hemodynamics, arterial blood gases, chest radiographs, spirometry, pulmonary complications, and time to extubation in a prospective trial of 200 patients randomized to OPCAB vs CABG/CPB performed by one surgeon.

RESULTS

One CABG/CPB patient and two OPCAB patients required mitral valve repair or replacement and were withdrawn. After three crossovers from CABG/CBP to OPCAB and one crossover from OPCAB to CABG, 97 CABG/CPB patients and 100 OPCAB patients remained. There were no significant preoperative demographic differences between groups. Postoperative compliance was reduced more after OPCAB than after CABG/CPB (- 15.4 +/- 10.7 mL/cm H(2)O vs - 11.2 +/- 10.1 mL/cm H(2)O [mean +/- SD]; p = 0.007), associated with rotation of the heart into the right chest to perform posterolateral bypasses (p < 0.001) and the concomitant increased fluid requirements necessary to maintain hemodynamic stability during rotation of the heart. In addition to higher intraoperative fluid intake (4,541 +/- 1,311 mL vs 3,585 +/- 1,033 mL, p < 0.0001), OPCAB patients had higher intraoperative fluid balance (3,903 +/- 1,315 mL vs 1,772 +/- 1,373 mL, p < 0.0001), and higher postoperative pulmonary arterial diastolic pressure (15.0 +/- 5.5 mm Hg vs 11.8 +/- 5.2 mm Hg, p < 0.0001) and central venous pressure (10.4 +/- 4.5 mm Hg vs 8.4 +/- 4.7 mm Hg, p < 0.0001). Despite lower compliance, immediate postoperative Pao(2) on fraction of inspired oxygen of 1.0 (275 +/- 97 torr vs 221 +/- 92 torr, p = 0.001) was higher after OPCAB and extubation was earlier (p = 0.001). Postoperative chest radiographs, spirometry, mortality, reintubation, or readmission for pulmonary complications were not different between groups.

CONCLUSIONS

Compared to CABG/CPB, OPCAB was associated with a greater reduction in postoperative respiratory compliance associated with increased fluid administration and rotation of the heart into the right chest to perform posterolateral grafts. OPCAB yielded better gas exchange and earlier extubation but no difference in chest radiographs, spirometry, or rates of death, pneumonia, pleural effusion, or pulmonary edema.

Similar pain scores after early and late extubation in heart surgery with cardiopulmonary bypass

OBJECTIVE

To investigate if early extubation, 2 hours after surgery, would result in more postoperative pain or in an increased use of opioid analgesics compared with late extubation, 6 hours after surgery.

DESIGN

Prospective, randomized study.

SETTING

Intensive care unit, university hospital.

PARTICIPANTS

Sixty patients undergoing cardiac surgery with cardiopulmonary bypass.

INTERVENTIONS

Patients were randomized into 2 groups: extubation at about 2 (early) or 6 (late) hours. Anesthesia was based on propofol and remifentanil. There was no epidural analgesia and no local anesthesia in the wound. A bolus of the opioid ketobemidone was administered toward the end of surgery followed by a continuous infusion.

MEASUREMENTS AND MAIN RESULTS

Pain, provoked during deep breathing or coughing, evaluated with a visual analog scale (VAS) going from 0 to 10, was measured after extubation, and at 8 and 16 hours after surgery. Unprovoked pain was measured hourly. If VAS was greater than 3, the infusion rate was increased and a bolus of ketobemidone was given. Three patients in the late group were excluded because of incomplete data. Pain did not differ between the early and late groups at any time. In all patients, 21 never scored >3, 11 scored >3 once, and 25 scored >3 more than once. Nine patients had 1 score >5. The amount of ketobemidone was similar in both groups.

CONCLUSIONS

Early extubation had no negative effect on the quality of postoperative pain control and was not followed by an increased use of analgesics.

Early extubation for adult cardiac surgical patients

BACKGROUND

Over 30 studies reported that early extubation (within eight hours) appears to be safe without an increased incidence of morbidity. A benefit of the practice may be cost savings associated with shorter Intensive Care Unit and hospital length of stays.

OBJECTIVES

To assess the effects of early extubation and the impact of the extubating clinician's profession on morbidity, mortality, intensive care unit and hospital length of stay, with a subgroup analysis for extubation within four hours or four to eight hours.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL)(issue 1, 2003), MEDLINE (January 1966 to June 2003), EMBASE (January 1980 to June 2003), CINAHL (January 1982 to December 2002), SIGLE(January 1980 to December 2002). We searched reference lists of articles and contacted researchers in the field.

SELECTION CRITERIA

Randomized controlled trials and controlled clinical trials of adult cardiac surgical patients (coronary artery bypass grafts, aortic valve replacement, mitral valve replacement, aortic aneurysm repair).

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial quality and extracted data. Study authors were contacted for additional information. A meta-analysis for most outcomes was conducted.

MAIN RESULTS

Six trials were included in the review. There was no evidence of a difference between early and conventionally extubated patients shown in the relative risk and 95% confidence interval for the following outcomes: mortality in intensive care was 0.8 (0.42 to 1.52); thirty day mortality was 1.2 (0.63 to 2.27); myocardial ischaemia was 0.96 (0.71 to 1.30); reintubation within 24 hours of surgery was 5.93 (0.72 to 49.14). Time spent in intensive care and in hospital were significantly shorter for patients extubated early (7.02 hours (- 7.42 to - 6.61) and 1.08 days ( - 1.35 to - 0.82) respectively).

REVIEWER'S CONCLUSIONS

There is no evidence of a difference in mortality and morbidity rates between the study groups. Early extubation reduces intensive care unit and hospital length of stay. Studies were underpowered and designed to show differences between study groups rather than equivalence between the groups. Suggested future areas of investigation: establishing the safety and efficacy of immediate extubation compared with early extubation; establishing the most effective means of pain control and reducing anxiety for patients; systematic reviews of the evidence for different parts of the patients journey through a cardiac surgery episode; and the impact of the profession of the clinician making the decision to extubate.