Morbidity outcome in early versus conventional tracheal extubation after coronary artery bypass grafting: a prospective randomized controlled trial

Outcomes of early extubation after bypass surgery in the elderly

BACKGROUND

While early extubation after coronary artery bypass grafting (CABG) has been associated with resource savings, its effect on patient outcomes remains unclear. The goal of the present investigation was to evaluate whether early extubation can be performed safely in elderly CABG patients in community practice.

METHODS

We studied 6,446 CABG patients, aged 65 years and older, treated at 35 hospitals between 1995 and 1998. Patients were categorized based on their post-CABG extubation duration (early, < 6 hours; intermediate, 6 to < 12 hours; and late, 12 to 24 hours). We compared unadjusted and risk-adjusted mortality, reintubation rates, and post-CABG length of stay (pLOS). We also examined the association between patients' intubation time and outcomes among patients with similar propensity for early extubation and among high-risk patient subgroups.

RESULTS

The overall mean post-CABG intubation time was 9.8 (SD 5.7) hours with 29% of patients extubated within 6 hours. After adjusting for preoperative risk factors patients extubated in less than 6 hours had significantly shorter postoperative hospital stays than those with later extubation times. Patients extubated early also tended to have equal or better risk-adjusted mortality than those with intermediate (odds ratio: 1.69, p = 0.08) or long intubation times (odds ratio: 1.97, p = 0.02). These results were consistent among patients with similar preoperative propensity for early extubation and among important high-risk patient subgroups. There was no evidence for higher reintubation rates among elderly patients selected for early extubation.

CONCLUSIONS

In community practice, early extubation after CABG can be achieved safely in selected elderly patients. This practice was associated with shorter hospital stays without adverse impact on postoperative outcomes.

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.

Alabama coronary artery bypass grafting project: results from phase II of a statewide quality improvement initiative

OBJECTIVE/BACKGROUND

This report describes the first round of results for Phase II of the Alabama CABG Project, a regional quality improvement initiative.

METHODS

Charts submitted by all hospitals in Alabama performing CABG (ICD-9 codes 36.10-36.20) were reviewed by a Clinical Data Abstraction Center (CDAC) (preintervention 1999-2000; postintervention 2000-2001). Variables that described quality in Phase I were abstracted for Phase II and data describing the new variables of beta-blocker use and lipid management were collected. Data samples collected onsite by participating hospitals were used for rapid cycle improvement in Phase II.

RESULTS

CDAC data (n = 1927 cases in 1999; n = 2001 cases in 2000) showed that improvements from Phase I in aspirin prescription, internal mammary artery use, and duration of intubation persisted in Phase II. During Phase II, use of beta-blockers before, during, or after CABG increased from 65% to 76% of patients (P < 0.05). Appropriate lipid management, an aggregate variable, occurred in 91% of patients before and 91% after the educational intervention. However, there were improvements in 3 of 5 subcategories for lipid management (documenting a lipid disorder [52%-57%], initiating drug therapy [45%-53%], and dietary counseling [74%-91%]; P < 0.05).

CONCLUSIONS

In Phase II, this statewide process-oriented quality improvement program added two new measures of quality. Achievements of quality improvement from Phase I persisted in Phase II, and improvements were seen in the new variables of lipid management and perioperative use of beta-blockers.

Factors associated with early extubation after cardiac surgery in young children

OBJECTIVE

Children undergoing congenital heart surgery require mechanical ventilation. We sought to identify pre- and intraoperative factors (PrO, IO) associated with successful early extubation <24 hrs.

DESIGN AND PATIENTS

We performed a retrospective chart review of children <36 months old who underwent congenital heart surgery from January 1998 to July 1999.

SETTING

Pediatric intensive care unit in a children's hospital.

MEASUREMENTS

Generalized Estimating Equation models were fit to assess the association between PrO and IO and early extubation while accounting for the correlation between surgeries performed on the same patient. Estimated odds ratios (EOR) and 95% confidence intervals were calculated. Multivariable models were constructed using a forward selection process with inclusion criteria of p<.05. Multivariable models, which included PrO and IO variables, were adjusted for procedure group. The area under the receiver operating characteristic curve was computed for each model.

RESULTS

A total of 203 children underwent 219 surgeries; 103 (47%) children were extubated in <24 hrs, with only one (1%) failed extubation. PrO variables associated with successful early extubation included age >6 months (EOR, 6.1), absence of pulmonary hypertension (EOR, 9.1), gestational age >36 wks (EOR, 4.6), and absence of congestive heart failure (EOR, 2.4). IO variables were less likely to be associated with successful early extubation. Our model of PrO variables with multiple factors showed that presence of two factors was associated with an EOR of 4.2 for successful early extubation compared with children with zero or one factor. Presence of three and four factors was associated with an EOR of 18.0 and 76.5, respectively. The area under the receiver operating characteristic curve for this model is 0.816. Incision type, complex vs. simple procedure, and palliative vs. complete repair were not associated with success of early extubation.

CONCLUSIONS

Early extubation is possible in many very young children undergoing congenital heart surgery, with a low rate of failed extubation. The model would be improved by prospective validation with larger numbers at multiple institutions.

Implications of the use of neuromuscular transmission monitoring on immediate postoperative extubation in off-pump coronary artery bypass surgery

BACKGROUND AND OBJECTIVE

When continuous infusions of neuromuscular blocking drugs are administered during lengthy interventions and no routine antagonism of their effects is applied, there is a dramatic incidence of residual curarization. We have examined whether the use of neuromuscular transmission monitoring results in differences in the incidence of postoperative residual curarization, the use of antagonist agents, and the endotracheal extubation rate and outcome after continuous infusion of rocuronium in patients undergoing off-pump coronary artery bypass surgery.

METHODS

Twenty patients were assigned to group 1 (n = 10, non-blinded neuromuscular transmission monitoring) or group 2 (n = 10, blinded neuromuscular transmission monitoring). In group 1, patients were given rocuronium at an infusion rate of 6 microg kg(-1) min(-1). The rate was manually adjusted in order to maintain T1/T0 at 10%. In group 2, a rocuronium infusion was started 30 min after induction of anaesthesia, at a rate of 6 microg kg(-1) min(-1); this rate was left unchanged during surgery. The rocuronium infusion was discontinued on completion of all vascular anastomoses; propofol was stopped at the beginning of closure of the subcutis and pirinitramide (piritramide) 15 mg was administered intravenously. Remifentanil was discontinued at the beginning of skin closure and neostigmine (50 microg kg(-1)) administered at the end of surgery when the train-of-four ratio was < 0.9 in group 1, and routinely in group 2. A 20 min test period for spontaneous ventilation was allowed once surgery had been accomplished. When the train-of-four ratio was > or = 0.9 (group 1), patients were extubated if also breathing spontaneously, fully awake and able to follow commands. When they met the clinical criteria for normal neuromuscular function after induced blockade, patients in group 2 were extubated when fully awake and able to follow commands.

RESULTS

In group 1, the rate of rocuronium infusion required to keep T1/T0 at 10% was 5 +/- 1.9 microg kg(-1) min(-1); this was not significantly different from the fixed rate in group 2 (P = 0.15). One patient in group 2 was excluded. Eight out of 10 and eight out of nine patients in groups 1 and 2, respectively, reached the extubation criteria. Three out of eight, and five out of eight, patients from groups 1 and 2, respectively, were extubated in the operating room. At that time of endotracheal extubation, all three patients from group 1, but only four of the five patients from group 2 had a train-of-four ratio > or = 0.9. In group 2, one patient was reintubated in the intensive care unit. The incidence of pharmacological reversal was high in group 1.

CONCLUSIONS

Although we found no additional benefit of using neuromuscular transmission monitoring, it seems an absolute necessity for safety reasons. Pharmacological antagonism was mandatory. However, in our opinion, it is not wise routinely to perform immediate postoperative extubation in off-pump coronary artery bypass surgery.

Criteria for immediate postoperative extubation in adult recipients following living-related liver transplantation with total intravenous anesthesia

STUDY OBJECTIVE

To evaluate whether our criteria for immediate postoperative extubation predicts successful extubation in living-related liver transplantation of the right lobe, and to test the effects of our standardized anesthetic technique on the success of immediate postoperative extubation.

DESIGN

Open-label, descriptive study.

SETTING

University hospital.

PATIENTS

6 ASA physical status III and IV patients with end-stage liver disease undergoing living-related liver transplantation of the right lobe.

INTERVENTIONS

Patients received a standardized anesthetic technique with propofol, remifentanil, and cisatracurium. They were extubated when they met our criteria for immediate postoperative extubation: good donor liver function, <10 U packed red blood cells administered, hemodynamic stability, and alveolar-arterial oxygen gradient <200 mmHg.

MEASUREMENTS AND MAIN RESULTS

At the end of surgery, four of the six patients fulfilled our criteria for immediate postoperative extubation. They were uneventfully extubated rapidly after surgery and soon arrived in the intensive care unit. Their postoperative stay in the operating room was only 36 minutes (range: 30 to 42 min). No patient required reintubation in the operating room or the intensive care unit. They had no recorded hemodynamic or respiratory problems postoperatively.

CONCLUSIONS

Immediate extubation of selected living-related liver transplant recipients can be a safe procedure. Anesthetic management to immediate extubation seems appropriate and the derived guidelines appear acceptable.

Heparin-coated circuits and reduced systemic anticoagulation applied to 2500 consecutive first-time coronary artery bypass grafting procedures

BACKGROUND

In contrast to the widespread popularity of off-pump techniques for coronary artery bypass grafting, our institution has chosen a different strategy, emphasizing improvements in the technology for extracorporeal circulation, as well as simplifying surgical and clinical management. The clinical short-term results of this approach were analyzed.

METHODS

The on-pump strategy includes routine use of heparin-coated circuits combined with low systemic heparinization (activated coagulation time of more than 250 seconds), intention of total revascularization within limited ischemic times and pump times, minimal use of blood transfusions, early extubation, and rapid postoperative recovery. The data from the first 2,500 consecutive first-time coronary artery bypass grafting patients (January 1998 to February 2002) treated with this protocol were retrospectively analyzed.

RESULTS

There were 487 female (median age 68 years) and 2013 male (median age 64 years) patients. A median of four (one to nine) (mean 4.5 +/- 1.2) distal anastomoses were created, and the median aortic cross-clamp time and pump time were 34 and 54 minutes, respectively. At least one internal mammary artery was used in 99.7% of the patients. Blood or bank blood products were given to 118 patients (4.7%). Median extubation time was 1.5 hours. The stroke rate was 0.8%, transient neurologic deficits occurred in 0.6% of the patients, and the incidence of perioperative myocardial infarction was 1.1%. By the fifth day, 91% of the patients were ready for discharge. Seven patients (0.28%) died during their hospital stay.

CONCLUSIONS

Coronary artery bypass grafting with heparin-coated cardiopulmonary bypass circuits and reduced systemic anticoagulation resulted in excellent clinical results, with minimal blood transfusions and rapid postoperative mobilization. The high number of grafted coronary arteries indicates complete revascularization in most patients, which is known to be a significant predictor of long-term event-free survival.

Outcome for cardiothoracic surgical patients requiring multidisciplinary intensive care

BACKGROUND AND OBJECTIVE

Patients who require multidisciplinary intensive care after cardiac surgery have a poor prognosis. The aim was to investigate factors in the mortality of this group of patients at 6 months.

METHODS

A retrospective analysis was made of the 6-month mortality rate in 301 adults who required admission to a multidisciplinary intensive care unit following cardiac surgery from 1991 to 1997. Mortality was correlated with clinical and patient characteristic variables.

RESULTS

The intensive care mortality rate was 34% and at 6 months after patients' discharge from intensive care it was 51%. There were positive correlations with death at 6 months for ventricular failure (odds ratio of death 3.4, P = 0.002), sepsis (odds ratio 3.0, P = 0.004) and age over 80 yr (odds ratio of death 9.2, P = 0.034). Patients who had undergone isolated coronary artery graft surgery (odds ratio of death 0.28, P = 0.036) or thoracic surgery (odds ratio of death 0.22, P = 0.042) had better 6-month outcomes. Patients with respiratory or renal failure in the absence of ventricular failure or sepsis had a 6-month mortality rate of 36%; but the lower mortality rate did not achieve statistical significance.

CONCLUSIONS

The 6-month mortality rate of 51% in a group of patients requiring multidisciplinary intensive care after cardiac surgery is consistent with previous studies; mortality was particularly high in extreme old age and in patients referred with sepsis or ventricular failure. Those patients with uncomplicated respiratory or renal failure had a better outcome than the group as a whole.

Readmission to the intensive care unit after "fast-track" cardiac surgery: risk factors and outcomes

BACKGROUND

The introduction of "fast-track" management into cardiac surgery has significantly shortened the intensive care unit (ICU) length of stay. Readmission to the ICU, traditionally used as a quality index, has not been investigated in these patients. The aim of this study was to assess the causes, risk factors, and outcomes associated with readmission to the ICU.

METHODS

All patients undergoing open-heart surgery in a tertiary care, university-affiliated center were included in this prospective observational study. Preoperative and intraoperative data as well as ICU outcome were noted in all patients.

RESULTS

Over the 27-month study period,1,613 patients were targeted for fast track management (discharge from ICU on the first postoperative day). The readmission rate was 3.29% (53 patients). Forty-three percent of readmissions occurred within 24 hours of discharge usually because of pulmonary problems (43%) or arrhythmias (13%). Readmission was associated with a prolonged ICU stay (105 +/- 180.0 versus 19.2 +/- 2.4 hours of initial ICU stay) and worse outcome: the only patients who died (6 of 53, 11.3%) were in this group. On multivariate analysis, a Bernstein-Parsonnet risk estimate more than 20 strongly predicted readmission (odds ratio, 3.08; 95% confidence interval, 1.43 to 6.69).

CONCLUSIONS

Among a homogeneous group of patients targeted for fast-track management after cardiac surgery, readmission although uncommon is associated with a longer second ICU stay and significant mortality. The recognition of specific risk factors may allow for appropriate modification of the postoperative course.

Intraoperative and postoperative risk factors for respiratory failure after coronary bypass

BACKGROUND

Unlike preoperative events, the influence of intraoperative or postoperative events on respiratory failure after coronary artery bypass grafting (CABG) remains unclear. The purpose of this study was to identify intraoperative and postoperative risk factors that predispose respiratory impairment after CABG.

METHODS

A single institutional database combined with a mandatory report submitted to the Cardiac Surgery Registry of the New York State Department of Health was used. A total of 8,802 consecutive patients who underwent primary CABG with or without a concomitant cardiac operation from January 1993 through December 2000 were included. Respiratory failure was defined as the need for postoperative mechanical ventilatory support longer than 72 hours. Univariate and multivariate logistic regression model was used in the analysis.

RESULTS

Of 8,802 consecutive patients (6,234 males and 2,568 females) who underwent CABG with or without a concomitant operation, 491 patients (5.6%) suffered from postoperative respiratory failure. Although univariate analysis identified 39 statistically significant preoperative risk factors for post-CABG respiratory failure, only six preoperative risk factors were statistically significant by multivariate analysis (p < 0.001). CPB time (in 30 minutes increments) was the only validated intraoperative variable that increased the risk of postrespiratory failure (odds ratio [OR], 1.2; p less than 0.0001). Postoperative events contributing significantly to an increased risk of post-CABG respiratory failure were (1) sepsis and endocarditis (OR, 90.4; p < 0.0001), (2) gastrointestinal bleeding with or without infarction and perforation (OR, 38.8; p < 0.0001), (3) renal failure (OR, 30.7; p < 0.0001), (4) deep sternal wound infection (OR, 11.3; p < 0.0001), (5) new stroke, intraoperative at 24 hours (OR, 9.3; p < 0.0001), and (6) bleeding that required reoperation (OR, 5.5; p < 0.0001). All perioperative variables together accounted for only 28.6% (R2) of the variation.

CONCLUSIONS

Respiratory function after CABG is readily influenced by postoperative occurrence of extracardiac organ or system complications.

Is very early extubation after lung transplantation feasible?

OBJECTIVE

To evaluate donor graft function, intraoperative blood consumption, and oxygenation and hemodynamic stability in patients undergoing lung transplantation.

DESIGN

Prospective pilot study.

SETTING

University hospital.

PARTICIPANTS

Forty-three patients undergoing lung transplantation from January 1999 to June 2001.

INTERVENTIONS

Hemodynamic monitoring, early extubation, and noninvasive ventilation criteria.

MEASUREMENTS AND MAIN RESULTS

The 31 nonearly extubated patients showed a lower PaO(2)/fraction of inspired oxygen (F(I)O(2)), a higher mean pulmonary arterial pressure, extravascular lung-water index (EVLWI) and vasoactive drug support (norepinephrine), and more blood products consumption than 12 early extubated patients at the end of surgery. Seven of 12 early extubated patients did not show any signs of respiratory failure after tracheal extubation; they were alert and able to perform deep breathing exercise and coughing. In the other 5 patients, hypoxemia, hypercapnia, and an increase of respiratory rate >30 breaths/min were observed. The intermittent application of noninvasive pressure ventilation by face mask avoided endotracheal intubation.

CONCLUSION

The use of a short-acting anesthetic drug, appropriate intraoperative extubation criteria, epidural analgesia, and postoperative noninvasive ventilation make early extubation of lung-transplanted patients possible and effective.

Comparison of three remifentanil dose-finding regimens for coronary artery surgery

OBJECTIVES

To identify the remifentanil dosing regimen providing safe and optimal anesthetic conditions during coronary artery bypass graft surgery and to evaluate postoperative recovery characteristics.

DESIGN

Open-label, randomized, parallel group.

SETTING

Three centers in the United States.

PARTICIPANTS

Seventy-two patients with left ventricular stroke volumes >or=50 mL.

INTERVENTIONS

Patients were randomized to remifentanil doses of 1 microg/kg/min (group 1, n = 23); 2 microg/kg/min (group 2, n = 24), or 3 microg/kg/min (group 3, n = 25). Somatic, sympathetic, and hemodynamic responses indicating inadequate anesthesia were treated with bolus doses of remifentanil, 1 to 2 microg/kg, and infusion rate increases, and, if necessary, isoflurane 0.5% to 1.0% was added as a rescue anesthetic. In the intensive care unit, the remifentanil infusion was reset to 1 microg/kg/min, with midazolam administered for supplemental sedation and morphine for analgesia.

MEASUREMENTS AND MAIN RESULTS

The durations of anesthesia, surgery, and cardiopulmonary bypass were similar for the 3 study groups. In addition, dose of lorazepam premedication, time to loss of consciousness, preoperative left ventricular ejection fraction, age, weight, and sex were similar for the 3 study groups. Remifentanil alone (infusion and boluses) prevented and controlled all responses to stimulation in 44% of group 3, 37% of group 2 and 9% of group 1 patients intraoperatively. Isoflurane (0.5%-1% inspired) rescue was successful in the remaining patients in each group. Hypotension indicating discontinuation of isoflurane and reductions of remifentanil infusion rates occurred in 64% to 75% of all patients. The optimal range of remifentanil infusion was 2 to 4 microg/kg/min with isoflurane to supplement the opioid. Fifty-one patients (71%) met the criteria for extubation within 6 hours postoperatively; because of surgical practice differences, only 30 patients (59%) were actually extubated.

CONCLUSIONS

After lorazepam premedication, remifentanil infusion (2-4 microg/kg/min) supplemented intermittently with low inspired concentrations of isoflurane provided an effective anesthetic regimen for coronary artery bypass graft surgery. Early extubation times were feasible after remifentanil continuous infusions (1-5 microg/kg/min) used as the primary anesthetic component intraoperatively and for analgesia (<or=1 microg/kg/min) in the immediate postoperative setting.

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.

A combination of intrathecal morphine and remifentanil anesthesia for fast-track cardiac anesthesia and surgery

OBJECTIVE

To determine if the combined remifentanil and intrathecal morphine (RITM) anesthetic technique facilitates early extubation in patients undergoing coronary artery bypass graft (CABG) surgery.

DESIGN

Prospective, randomized, controlled clinical trial.

SETTING

Referral center for cardiothoracic surgery at a university hospital.

PARTICIPANTS

Patients (n = 24) undergoing first-time elective CABG surgery.

INTERVENTIONS

Two groups represented RITM (n = 12) and fentanyl-based (controls, n = 12) anesthesia. Premedication was standardized to temazepam, 0.4 mg/kg, and anesthesia was induced with etomidate, 0.3 mg/kg, in both groups. The RITM group received remifentanil, 1 microg/kg bolus followed by 0.25 to 1 microg/kg/min infusion, and intrathecal morphine, 2 mg. The control group received fentanyl, 12 microg/kg in 3 divided doses. Anesthesia was maintained with isoflurane and pancuronium in both groups. After completion of surgery, the remifentanil infusion was stopped. Complete reversal of muscle relaxation was ensured with a nerve stimulator, and a propofol infusion, 0.5 to 3 mg/kg/h, was started in both groups. All patients were transferred to the intensive care unit (ICU) to receive standardized postoperative care. Intensivists and ICU nurses were blinded to the group assignment. Propofol infusion was stopped, and the tracheal extubation was accomplished when extubation criteria were fulfilled.

MEASUREMENTS AND MAIN RESULTS

Both groups were similar with respect to demographic data and surgical characteristics. Extubation times were 156 +/- 82 minutes and 258 +/- 91 minutes in the RITM and control groups (p = 0.012). Patients in the RITM group exhibited lower visual analog scale pain scores during the first 2 hours after extubation (p < 0.04). Morphine requirements during the 24 hours after extubation were 2.5 +/- 3 mg in the RITM group and 16 +/- 11 mg in the control group (p = 0.0018). Sedation scores were lower in the RITM group during the first 3 hours after extubation (p < 0.03). Pulmonary function tests as assessed by spirometry were better in the RITM group at 6 and 12 hours after extubation (p < 0.04). There were no significant differences in PaO(2) and PaCO(2) after extubation between the 2 groups. None of the patients had episodes of apnea during the immediate 24-hour postextubation period. Two patients from the RITM group required reintubation on the second and sixth postoperative days. There were no differences in ICU and hospital length of stay between the 2 groups.

CONCLUSION

Implementation of the RITM technique provided earlier tracheal extubation, decreased level of sedation, excellent analgesia, and improved spirometry in the early postoperative period. The impact of RITM on ICU and hospital length of stay and potential cost benefits require further evaluation.

Remifentanil-clonidine-propofol versus sufentanil-propofol anesthesia for coronary artery bypass surgery

OBJECTIVE

To compare a remifentanil-clonidine-propofol regimen with conventional sufentanil-propofol anesthesia.

DESIGN

Randomized, nonblinded trial.

SETTING

A single university hospital.

PARTICIPANTS

Male patients scheduled for coronary artery bypass graft (CABG) surgery.

INTERVENTIONS

In the control group, anesthesia was induced with 0.5 microg/kg of sufentanil and 0.2 to 0.3 mg/kg of etomidate after preoxygenation. Propofol (50 to 100 microg/kg/min) and sufentanil (0.5 to 1.0 microg/kg/h) were started after endotracheal intubation. Sufentanil was stopped after aortic decannulation. In the remifentanil-clonidine group, anesthesia was started with remifentanil (0.15 to 0.3 microg/kg/min), followed by etomidate (0.2 to 0.3 mg/kg). Propofol was started at 50 to 100 microg/kg/min, and after endotracheal intubation, clonidine infusion was started (6 to 20 microg/h). Patients received piritramide (0.15 mg/kg) and metamizole (20 mg/kg) for transitional analgesia. In both groups, propofol infusion was reduced to 30 to 60 microg/kg/min at skin closure and stopped when assisted spontaneous breathing led to adequate gas exchange.

MEASUREMENTS AND MAIN RESULTS

The main outcomes were recovery times; somatic variables; plasma catecholamine levels; and self-recorded pain, nausea, and vomiting. Patients in the remifentanil-clonidine group were extubated earlier and had lower plasma epinephrine and norepinephrine levels. After transitional analgesia, the remifentanil-clonidine patients had similar postoperative analgesic use and self-reported pain and side-effect scores.

CONCLUSION

Compared with a sufentanil-propofol regimen, an anesthetic regimen for CABG surgery that combines remifentanil, clonidine, and propofol provides similar hemodynamics. The remifentanil-clonidine regimen reduces catecholamine levels and hastens recovery from anesthesia.

Do intraoperative variables have an effect on the timing of tracheal extubation after coronary artery bypass graft surgery?

OBJECTIVE

The purpose of this study was to investigate whether any intraoperative variable had a significant effect on extubation time after coronary artery bypass graft surgery.

DESIGN

Study design was a retrospective study.

SETTING

Study took place in 1 cardiac center in the United Kingdom that had 1000 cases per year.

SUBJECTS

Eighty-nine patients had coronary artery bypass graft surgery in the first 6 months of 1998 performed by one consultant cardiac surgeon.

OUTCOME MEASURES

Study measures included intraoperative variables (number of vessels grafted, time on cardiopulmonary bypass [CPB], length of the operation, use of internal mammary artery) and extubation time.

RESULTS

Mean extubation time was 4.97 hours. On analysis via linear regression no intraoperative variables were found to be statistically significant (P = .05) to extubation time.

CONCLUSION

This study identified that early extubation can be achieved safely. Although no variable was found to have a significant effect on extubation time, the relationship between CPB and extubation may have been attributed to the low mean CPB time within the study (49.1 minutes). The relationship between cardiac status, ischemia, and the timing of extubation does warrant additional exploration.

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.

Anesthetic and perfusion issues in contemporary pediatric cardiac surgery

As the fields of pediatric cardiology and cardiac surgery advance in complexity and in accountability for clinical and economic outcomes, several issues traditionally associated with the operating room are becoming important to physicians, nurses, and respiratory therapists who take care of children after cardiac surgery. The article discusses the concepts of "fast track" cardiac surgery, regional anesthetic techniques, coagulopathies and bleeding after cardiopulmonary bypass, intraoperative ultrafiltration, and mechanical circulatory assist devices.

Safety and efficacy of fast track in patients undergoing coronary artery bypass surgery

BACKGROUND

The incidence of coronary artery bypass surgery has been increasing annually with increasing pressure on the health care system. Fast track has been proposed as a means to increase efficiency and volume, without an increase in hospital resources. To date this approach has not been critically assessed in Canada.

METHODS

We examined 617 consecutive patients undergoing isolated CABG surgery. The patients were divided into (1) fast track (FT) recovery (n = 219), without admission to an ICU, and (2) non-fast track (NFT) recovery (n = 398) with direct admission to the ICU. There were no differences in age, gender, timing of surgery, left main stenosis, preoperative myocardial infarction, renal failure, diabetes, peripheral vascular disease, or in the incidence of chronic obstructive pulmonary disease between the two groups. The NFT group had a higher proportion of patients with NYHA Class III/IV symptoms preoperatively (65.7% vs. 57.3%, p = 0.048), in patients with an ejection fraction < 40% (42.5% vs. 30.6%, p = 0.004), or in the number of individuals with an IABP inserted before surgery (13 vs. 1, p < 0.001).

RESULTS

In the FT group the average period of aortic occlusion (40.7 +/- 15.2 min vs. 71.8 +/- 26.5 min, p < 0.001) and perfusion time (67.8 +/- 24.5 min vs. 117.5 +/- 40.2 min, p < 0.001) were significantly less than in the NFT group. The number of grafts per patient was 3.3 +/- 1.0 vs. 3.2 +/- 1.0, respectively (p = 0.38). Operative mortality was 0.9% in the FT group and 1.3% in the NFT group (p = 1.0). Significant differences were seen in the proportion of patients that suffered from postoperative ventilatory failure (3.2% in FT vs. 12.1% in NFT, p < 0.001), and the proportion of patients that suffered any postoperative complication was significantly higher in the NFT group (21.4%) than in the FT group (9.1%, p < 0.001). The differences in postoperative complications resulted in a shorter length of stay (LOS) in FT patients (5.6 +/- 4.1 days vs. 9.7 +/- 9.4 days NFT, p < 0.001). Only 4.1% of patients that entered the FT group failed and required admission to the ICU. Multivariate stepwise logistic regression analysis identified non-fast track recovery as an independent predictor of morbidity in CABG surgery patients.

CONCLUSIONS

The data indicate it is possible to perform isolated CABG surgery, in a large proportion of the population, without the need for admission to an ICU for postoperative care.

Failed extubation after cardiac surgery in young children: Prevalence, pathogenesis, and risk factors

Background: Most children who undergo congenital heart surgery require postoperative mechanical ventilation. Failed extubation (FE) may result in physiologic instability, delay, or set back of the weaning process. FE is statistically associated with prolonged mechanical ventilation. Purpose: We sought to identify frequency, pathogenesis, and risk factors for FE after congenital heart surgery in young children. SETTING: Pediatric intensive care unit. PATIENTS: Children </=36 months of age who underwent congenital heart surgery in the period between January 1998 and July 1999 at our children's hospital. Measurements and Statistical Methods: We performed a retrospective chart review. We defined reintubation within 24 hrs as an FE. Demographic, preoperative, intraoperative, and postoperative data were collected. A modified version of logistic regression, which accounts for lack of independence in data with multiple records per subject, was used to assess the impact of risk factors for FE. A forward selection process was used with p <.05 as the criterion for entry into the model. Estimated odds ratios (EORs) are reported with 95% confidence intervals (CI). The predictive ability of the final model was assessed by using area under the receiver operating characteristic curve. MAIN RESULTS: A total of 212 children </=36 months of age underwent 230 congenital heart operations. Eleven children (5.2%) died perioperatively. After excluding patients who died, there were 219 surgeries among 202 patients; 25.9% (51 of 197), 51.8% (102 of 197), and 72.6% (143 of 197) of patients were successfully extubated by 12, 24, and 48 hrs, respectively. There were 22 cases in which an initial attempt at extubation failed at a median of 67.8 hrs (range, 2.4-335.5 hrs). Five patients failed a subsequent attempt at extubation at a median of 189.5 hrs (range, 115.8-602.5 hrs). The most common causes of initial FE were cardiac dysfunction (n = 6), lung disease (n = 6), and airway edema (n = 3). Risk factors for FE included pulmonary hypertension (EOR, 38.7; 95% CI, 2.9-25.8; p <.001), Down syndrome (EOR, 4.6; 95% CI, 1.8-11.8; p =.002), and deep hypothermic circulatory arrest (EOR, 4.5; 95% CI, 1.3-17.5; p =.018). All were independent predictors of FE (area under the curve, 0.837). The strongest predictor was pulmonary hypertension, which when used alone to predict FE provided a sensitivity of 0.83 (95% CI, 0.59-0.94) and a specificity of 0.75 (95% CI, 0.68-0.80). CONCLUSIONS: Extubation fails after approximately 10% of congenital heart surgery in young patients. Causes of FE are diverse. In our population, preoperative pulmonary hypertension, presence of a congenital syndrome, and intraoperative circulatory arrest are risk factors for FE. Prospective validation of our predictive model with larger numbers and at multiple institutions would improve its utility.

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

OBJECTIVE

To evaluate the effect of a short period of mechanical ventilation (3 hours) versus immediate extubation (within 1 hour of surgery) on pulmonary function, gas exchange, and pulmonary complications after coronary artery bypass graft (CABG) surgery.

DESIGN

Prospective randomized study.

SETTING

University teaching hospital.

PARTICIPANTS

Thirty-five patients undergoing CABG surgery.

INTERVENTIONS

Patients were randomized into 2 groups. Patients in group I were extubated as soon as possible after surgery. Patients in group II were ventilated for a minimum of 3 hours after surgery. Patients in both groups were extubated only after achieving predetermined extubation criteria. Patients who did not meet the criteria for extubation within the predetermined set time limit (90 minutes in group I and 6 hours in group II) were withdrawn from the study. Pulmonary function tests (vital capacity, forced expiratory volume in 1 second, total lung capacity, functional residual capacity), arterial blood gases, and chest radiographs were done preoperatively and postoperatively. Pulmonary complications were recorded.

MEASUREMENTS AND MAIN RESULTS

Demographic data were similar between groups. The mean time to extubation in group I was 45.7 plus minus 27.6 minutes and in group II was 201.4 plus minus 21 minutes (p < 0.01). Two patients in group I and 1 patient in group II did not meet the extubation criteria within the predetermined set time limit and were excluded from the study. In both groups, there was a significant decline in pulmonary function but no differences between groups at 24 or 72 hours after surgery. There were no differences between groups in blood gases, atelectasis scores, or pulmonary complications.

CONCLUSION

The data suggest that extending mechanical ventilation after CABG surgery does not affect pulmonary function. Provided that routine extubation criteria are met, patients can be safely extubated early (within 1 hour) after major cardiac surgery without concerns of further pulmonary derangement.

Retrospective study on the need of intensive care unit admission after major head and neck surgery

BACKGROUND

The present article aims to study the pattern and need of Intensive Care Unit admission after major head and neck operations.

METHODS

A retrospective study was undertaken of the hospital records of patients who underwent major head and neck operations during the period from February 1997 to February 2000 at the Division of Head and Neck Surgery, Department of Surgery, the Chinese University of Hong Kong.

RESULTS

A total of 268 consecutive elective major operations were carried out over the 3 year period. The patients' age ranged from 14 to 82 years with a mean of 55 years. The male to female ratio was 4:1. Forty-seven patients underwent an operation with a combination of major resection, neck dissection, flap reconstruction and tracheostomy ('flaps group'). Two hundred and twenty-one patients had major head and neck operations without the need of flap reconstruction ('non-flaps group'). Three (6.3%) out of 47 patients (flaps group) were admitted to intensive care unit (ICU) immediately after the operation. Only one patient (2.2%) out of the remaining 44 patients was admitted for emergency treatment 3 weeks post operation. All four patients recovered uneventfully. In the non-flaps group of 221 patients, there were 12 (5.4%) planned admissions and 2 (0.96%) unplanned admissions to ICU. In the group of planned admissions, one out of the 12 patients died. The other two patients who were not planned for ICU admission died of basal meningitis that was disease-related rather than related to the intensity of postoperative care. The overall admission rate to ICU was 18 (6.7%) out of 268 patients. The overall mortality was 1.1% (one planned, two unplanned).

CONCLUSION

The present study showed that it is safe and cost-effective to discharge the majority of patients after major head and neck operations back to a specialist ward for nursing care.

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.

Trials comparing alternative weaning modes and discontinuation assessments

We identified 16 randomized controlled trials (RCTs) of methods for weaning patients from mechanical ventilation, 8 of which were trials of discontinuation assessment strategies, 5 of which were trials of stepwise reduction in mechanical ventilatory support, and 3 of which were trials comparing alternative ventilation modes for weaning periods lasting < 48 h. We found that different thresholds for deciding when a patient is ready for a trial of spontaneous breathing, different criteria for a successful trial, and different thresholds for extubation may overwhelm the impact of alternative ventilation strategies. Nevertheless, the results of these studies suggest the possibility that multiple daily T-piece weaning or pressure support may be superior to synchronized intermittent mandatory ventilation. Other RCTs suggest that early extubation with the back-up institution of noninvasive positive-pressure ventilation as needed may be a useful strategy in selected patients.

Off-Pump Coronary Artery Bypass Surgery: Revival of an Old Technique

The ability to perform surgical procedures on the heart was one of the greatest accomplishments of the 20th century. What was once considered an impossible task has become a routine in daily clinical activity. The in troduction of extracorporeal circulation and myocardial protection strategies opened the doors to what was considered by most an insurmountable barrier— unhin dered access to the coronary circulation and intracar diac structures. In the United States, approximately 85% of coronary artery bypass graft procedures are performed with the use of cardiopulmonary bypass (CPB). CPB was and remains the gold standard for this type of cardiac surgical intervention. Over the years, investigators have struggled to find ways of lessening or eliminating the adverse physiologic effects of CPB. These efforts have focused on pharmacologic interven tion, monitoring procedures, blood gas management, and temperature management. Another way of avoid ing these effects is inherently obvious — eliminate the main source of the problem.

Quality care outcomes in cardiac surgery: the role of evidence-based practice

An internal database and research methods were used to evaluate the impact of clopidogrel on cardiac surgical bleeding. This quality improvement initiative, led by the clinical nurse specialist, showed that preoperative exposure to clopidogrel was associated with significant increases in chest tube output, blood product use, and reoperation for bleeding rates that were 10-fold higher than for control patients (0.85% versus 8.3%, P = 0.027). Acute care costs averaged $2,680 more for patients who received clopidogrel (P = 0.1936). After implementation of an interdepartmental clinical practice guideline, preoperative exposure to clopidogrel dropped from 39% to 6.3% (P = 0.0000). This drop was accompanied by reductions in chest tube output, blood product use, and bleeding complications, with improved achievement of clinical benchmarks. The availability of internal evidence to support achievement of best practices was an essential factor in the implementation of this interdepartmental change. Comprehensive database systems and advanced practice nurses are highlighted as essential components of evidence-based programs.

Comparative efficacy and safety of remifentanil and fentanyl in 'fast track' coronary artery bypass graft surgery: a randomized, double-blind study

This multi-centre, parallel group, randomized, double-blind study compared the efficacy and safety of high-dose remifentanil administered by continuous infusion with an intermittent bolus fentanyl regimen, when given in combination with propofol for general anaesthesia in 321 patients undergoing elective coronary artery bypass graft surgery. A significantly lower proportion of the patients who received remifentanil had responses to maximal sternal spread (the primary efficacy endpoint) compared with those who received fentanyl (11% vs 52%; P<0.001). More patients who received remifentanil responded to tracheal intubation compared with those who received fentanyl (24% vs 9%; P<0.001). However, fewer patients who received remifentanil responded to sternal skin incision (11% vs 36%; P<0.001) and sternotomy (14% vs 60%; P <0.001). Median time to extubation was longer in the subjects who received remifentanil than for those who received fentanyl (5.1 vs 4.2 h; P=0.006). There were no statistically significant differences between the two groups in the times for transfer from intensive care unit or hospital discharge but time to extubation was significantly longer in the remifentanil group. Overall, the incidence of adverse events was similar but greater in the remifentanil group with respect to shivering (P<0.049) and hypertension (P<0.001). Significantly more drug-related adverse events were reported in the remifentanil group (P=0.016). There were no drug-related adverse cardiac outcomes and no deaths from cardiac causes before hospital discharge in either treatment group.

Does extubation result in haemodynamic instability in patients following coronary artery bypass grafts?

Coronary heart disease and its management continue to be at the centre of Government health policy. The present political climate demands clinical effectiveness and best practice should be established, while maintaining the philosophy of cost-effectiveness and resource management. These directives have led practitioners to question the care of patients following coronary artery bypass surgery, in particular the role of mechanical ventilation and the subsequent act of extubation. A retrospective study of 89 patients who had coronary artery bypass grafts (emergency and elective) was undertaken, to establish if extubation had a significant effect on the haemodynamic status of patients with variable degrees of left ventricular function (19% with poor left ventricular function). The study found that extubation was achieved within a mean time of 4.97 hours following return from surgery. Extubation resulted in a significant increase in heart rate (P = 0.001), as well as a respiratory acidosis (pCO2: P = 0.000; pH: P = 0.000). However, the stability of the patient was not compromised, with neither mean arterial blood pressure (P = 0.825) nor oxygenation levels (P = 0.267) being significantly altered by extubation. On multivariate analysis, the act of extubation had no significant effect on any of the dependent variables. These results suggest that it is not extubation alone that has an impact on the haemodynamic stability of patients following coronary artery bypass grafts, but that this is indeed multifactorial. Therefore extubation is 'safe' practice for patients with varying degrees of left ventricular function following coronary artery bypass grafts. Limitations of the study are acknowledged.

Using protocols to improve the outcomes of mechanically ventilated patients. Focus on weaning and sedation

The use of nonphysician-directed protocols and guidelines for the management of sedation and weaning has been shown to reduce the duration of mechanical ventilation for patients with acute respiratory failure when compared with conventional physician-directed practices. Practitioners in ICUs frequently are needed to perform multiple tasks and to evaluate numerous elements of clinical information in the care of the critically ill. In this complex environment, protocols and guidelines are one strategy for ensuring that specific tasks are carried out in a timely manner. Simple-to-employ methods for facilitating changes and improvements in the care of hospitalized patients recently have been proposed. These methods emphasize the importance of developing a culture of cooperation within the ICU so protocols and guidelines can be implemented successfully. Such a culture should embrace changes in medical practices in the ICU if they are associated with improved clinical outcomes. The results of studies evaluating the use of protocols and guidelines have important implications for general critical care practices, because many ICUs do not have physicians who are constantly at the patient's bedside. The need for effective communication from the bedside caregiver (e.g., nurse, respiratory therapist, pharmacist, technician) to the physician, so that treatment orders can be changed appropriately, usually results in some delay in the implementation of treatment changes. Protocols are one method for potentially reducing those delays and ensuring that medical care is administered in a more standardized and efficient manner.

Anxiety, delirium, and pain in the intensive care unit

Anxiety, agitation, delirium, and pain are common findings in the ICU. These unhealthy states may lead to increased irritability, discomfort, hypertension, tachycardia, cardiac ischemia, harmful motor activity, and psychologic disquiet for the patient. The appropriate treatment of these conditions may lead to decreased morbidity and mortality in the critically ill patient. Unfortunately, the management of anxiety, agitation, delirium, and pain in the intensive care unit is not ideal. Many patients interviewed after an ICU stay rate their pain control as poor and their memories of their stay as unpleasant. Furthermore, many caregivers lack sufficient understanding of the appropriate or indicated uses of drugs to allay patients' fears and pain. The use of suitable protocols for the proper titration of sedation of mechanically ventilated patients and monitoring of the level of sedation in ventilated patients may decrease the amount of time that patients are ventilated and may alleviate some of the emotional stresses of recall of painful procedures or uncomfortable mechanical ventilation. Future research into protocols for the care of the critically ill patient can enhance the overall well-being of these patients.

Early extubation after cardiac surgery: emotional status in the early postoperative period

OBJECTIVE

To compare the emotional state during the first 3 days after coronary artery surgery of patients who had undergone early versus conventional extubation.

DESIGN

A prospective, randomized, controlled trial.

SETTING

University hospital, single center.

PARTICIPANTS

Eligible patients (n = 100) presenting for elective coronary artery surgery, randomized to an early extubation group or a conventional extubation group.

INTERVENTIONS

Emotional status was measured by the Hospital Anxiety and Depression Scale (HAD), the Self Assessment Manikin (SAM), and the Multiple Affect Adjective Check List-Revised (MAACL-R). Tests were administered preoperatively and on the 1st and 3rd days postoperatively.

MEASUREMENTS AND MAIN RESULTS

Of patients in the conventional extubation group, 30% showed moderate-to-severe depressive symptoms (HAD score >10) on day 3 postoperatively compared with 8% of patients in the early extubation group (p = 0.02). There was a clinically insignificant increase in MAACL-R depression score on the 1st postoperative day within both groups but no other differences within or between groups in SAM or MAACL-R scores.

CONCLUSION

Early extubation results in fewer patients displaying depressive symptoms on the 3rd postoperative day but appears to have little effect on other measurements of emotional status. Anesthetic management during coronary artery bypass graft surgery may play an important role in the overall well-being of the patient by decreasing the incidence of postoperative depression.

Early tracheal extubation after paediatric cardiac surgery: the use of propofol to supplement low-dose opioid anaesthesia

BACKGROUND

After institutional approval and parental consent, 103 children, aged 6 months to 18 years, who were undergoing repair of simple and complex congenital heart lesions using cardiopulmonary bypass (CPB) were studied and compared with a group of 135 children who had undergone similar surgery in our institution in the year before.

METHODS

Anaesthesia for study patients included fentanyl (< 20 microg.kg-1) and isoflurane. Infusions of propofol (median infusion rate 70 microg.kg-1.min-1) and morphine (median infusion rate 20 microg.kg-1.h-1) were started after weaning from CPB and continued postoperatively. Preestablished criteria were used in the intensive care unit (ICU) to assess readiness for tracheal extubation.

RESULTS

Median time from admission to ICU to tracheal extubation was 5 h. Fifty-six children were extubated within 6 h and 73 within 9 h of ICU admission. Mean ICU stay for study patients was 1.7 days [95% confidence interval (CI) 1.2-2.2] and 2.6 days (95% CI 2.3-2.9) in the comparison group (P<0.005).

CONCLUSIONS

We found the propofol regimen to be satisfactory with a shorted ICU stay for these patients.

A randomized double-blinded multicenter comparison of remifentanil versus fentanyl when combined with isoflurane/propofol for early extubation in coronary artery bypass graft surgery

We compared a fentanyl/isoflurane/propofol regimen with a remifentanil/isoflurane/propofol regimen for fast-track cardiac anesthesia in a prospective, randomized, double-blinded study on patients undergoing elective coronary artery bypass graft surgery. Anesthesia was induced with a 1-min infusion of 0.5 mg/kg propofol followed by 10-mg boluses of propofol every 30 s until loss of consciousness. After 0.2 mg/kg cisatracurium, a blinded continuous infusion of remifentanil at 1 microg. kg(-1). min(-1) or the equivalent volume rate of normal saline was then started. In addition, a blinded bolus syringe of 1 microg/kg remifentanil or 10 microg/kg fentanyl, respectively, was given over 3 min. Blinded remifentanil, 1 microg. kg(-1). min(-1) (or the equivalent volume rate of normal saline), together with 0.5% isoflurane, were used to maintain anesthesia. Significantly more patients (P < 0.01) in the fentanyl regimen experienced hypertension during skin incision and maximum sternal spread compared with patients in the remifentanil regimen. There were no differences between the groups in time until extubation, discharge from the surgical intensive care unit, ST segment and other electrocardiogram changes, catecholamine levels, or cardiac enzymes. The remifentanil-based anesthetic (consisting of a bolus followed by a continuous infusion) resulted in significantly less response to surgical stimulation and less need for anesthetic interventions compared with the fentanyl regimen (consisting of an initial bolus, and followed by subsequent boluses only to treat hemodynamic responses) with both drug regimens allowing early extubation.

IMPLICATIONS

Both fentanyl and the newer opioid remifentanil, when each is combined with isoflurane and propofol, allowed for fast-track cardiac anesthesia. The remifentanil regimen used in this study resulted in significantly less hemodynamic response to surgical stimulation.

The efficacy and resource utilization of remifentanil and fentanyl in fast-track coronary artery bypass graft surgery: a prospective randomized, double-blinded controlled, multi-center trial

We compared (a) the perioperative complications; (b) times to eligibility for, and actual time of the following: extubation, less intense monitoring, intensive care unit (ICU), and hospital discharge; and (c) resource utilization of nursing ratio for patients receiving either a typical fentanyl/isoflurane/propofol regimen or a remifentanil/isoflurane/propofol regimen for fast-track cardiac anesthesia in 304 adults by using a prospective randomized, double-blinded, double-dummy trial. There were no differences in demographic data, or perioperative mortality and morbidity between the two study groups. The mini-mental status examination at postoperative Days 1 to 3 were similar between the two groups. The eligible and actual times for extubation, less intense monitoring, ICU discharge, and hospital discharge were not significantly different. Further analyses revealed no differences in times for extubation and resource utilization after stratification by preoperative risk scores, age, and country. The nurse/patient ratio was similar between the remifentanil/isoflurane/propofol and fentanyl/isoflu-rane/propofol groups during the initial ICU phase and less intense monitoring phase. Increasing preoperative risk scores and older age (>70 yr) were associated with longer times until extubation (eligible), ICU discharge (eligible and actual), and hospital discharge (eligible and actual). Times until extubation (eligible and actual) and less intense monitoring (eligible) were significantly shorter in Canadian patients than United States' patients. However, there was no difference in hospital length of stay in Canadian and United States' patients. We conclude that both anesthesia techniques permit early and similar times until tracheal extubation, less intense monitoring, ICU and hospital discharge, and reduced resource utilization after coronary artery bypass graft surgery.

IMPLICATIONS

An ultra-short opioid technique was compared with a standard fast-track small-dose opioid technique in coronary artery bypass graft patients in a prospective randomized, double-blinded controlled study. The postoperative recovery and resource utilization, including stratification of preoperative risk score, age, and country, were analyzed.

Ultra-fast-track anesthetic technique facilitates operating room extubation in patients undergoing off-pump coronary revascularization surgery

OBJECTIVE

To determine if implementation of ultra-fast-track anesthetic (UFTA) technique facilitates operating room extubation in patients undergoing off-pump coronary artery bypass graft (CABG) surgery.

DESIGN

Retrospective review.

SETTING

Referral center for cardiovascular surgery at a university hospital.

PARTICIPANTS

Thirty-seven patients undergoing off-pump CABG surgery.

INTERVENTIONS

Two groups represented UFTA (n = 10) and standard anesthetic (controls, n = 27) techniques. Anesthesia was conducted with propofol, remifentanil, vecuronium, and thoracic epidural analgesia in the UFTA group and thiopental, fentanyl, pancuronium, and isoflurane in the control group. Active temperature control was an integral part of the UFTA technique but not the standard technique. The active temperature control included intravenous fluid warmer, prewarmed skin preparation, humidified inspired gases, a circulating water warming blanket, and a forced-air warmer, along with the maintenance of the operating room temperature at 24 degrees C. The control group was managed with an intravenous fluid warmer, and the ambient temperature remained constant (20 degrees C). Patients who did not satisfy extubation criteria within 30 minutes from the end of surgery were sedated and transferred to the intensive care unit (ICU).

MEASUREMENTS AND MAIN RESULTS

All patients in the UFTA group and 2 in the control group were extubated in the operating room immediately after surgery. None of the patients required reintubation. There was no significant difference in postextubation PaO(2) and PaCO(2) between the groups. Nasopharyngeal temperature decreased from 36.7 +/- 0.4 degrees C to 36.4 +/- 0.3 degrees C in the UFTA group and from 36.6 +/- 0.5 degrees C to 35.6 +/- 0.4 degrees C in the control group (p < 0.0001). Bradycardia occurred significantly more often in the UFTA group but there was no difference in episodes of hypotension. There were no perioperative deaths. Patients who were extubated in the operating room required lower nurse-to-patient acuity ratio (1:2) in the ICU. No difference was found in ICU and hospital length of stay.

CONCLUSIONS

Implementation of UFTA technique provided adequate hemodynamic control and facilitated operating room extubation in all patients. The impact of UFTA on earlier patient discharge and actual cost savings within a fully integrated post-cardiac surgery unit requires further evaluation.

Predictive risk factors for pulmonary oxygen transfer in patients undergoing coronary artery bypass grafting

The ratio of arterial oxygen tension to inspired oxygen fraction (PaO2/FiO2) is a useful indicator for weaning patients from mechanical ventilation and a reliable predictor of pulmonary dysfunction after cardiac surgery. The aim of this study was to elucidate the patient characteristics and variables that affect the PaO2/FiO2 ratio. Between 1994-1998, 167 patients who underwent coronary artery bypass grafting (CABG) were examined retrospectively. Spearman's correlation coefficients were calculated between the PaO2/FiO2 ratio and intubation period, and length of ICU stay. Patients were then divided into two groups with a PaO2/FiO2 ratio < 350 and PaO2/FiO2 ratio > or = 350. Univariate analysis of the putative risk factors was performed. A logistic regression model was developed to evaluate factors that would influence the PaO2/FiO2 ratio. A significant correlation was observed between the PaO2/FiO2 ratio and intubation period, and length of ICU stay. Univariate predictors of a PaO2/FiO2 ratio < 350 were low body weight, low preoperative PaO2 long operation time, high FiO2, low postoperative PaO2 history of smoking, hypertension and opening of pleura (p < 0.05). Excellent prediction was found with a model consisting of preoperative PaO2 and hypertension.

CONCLUSION

The results of this study suggest that patients with a low preoperative PaO2 or hypertension may need more careful peri- and postoperative management since these factors are closely associated with the PaO2/FiO2 ratio.

Postoperative intensive care in cardiac surgery

Postoperative intensive care in cardiac surgery is a growing area, fuelled by the increase in the number of cardiac surgical procedures performed. An increase in the number of patients has resulted in increased resource utilization. Much of the recent research in this field is concerned with the early extubation of cardiac surgical patients, reducing the length of stay in the intensive care unit and predicting which patients will have delayed extubation and a prolonged length of stay. A number of recent studies have been published advocating 'off pump' cardiac surgery as a way of reducing the physiological insult of cardiopulmonary bypass and thereby improving the postoperative course. There is still insufficient evidence that this approach reduces morbidity and intensive care unit length of stay in multi-vessel off-pump coronary artery bypass surgery. The traditional design of post-cardiac surgical intensive care units and high dependency units has also recently been challenged. More flexible integrated units improve cost control and are more suited to modern cardiac surgery.

Reoperative coronary bypass surgery: effect of patent grafts and retrograde cardioplegia

OBJECTIVE

To determine the effects of patent or diseased aorta-coronary bypass grafts and retrograde cardioplegia on mortality during reoperative coronary bypass surgery.

METHODS

We conducted a retrospective review of prospectively gathered data, supplemented by systematic chart review, of all patients (n = 744) undergoing reoperative coronary bypass surgery at our institution between 1990 and 1997. Independent predictors of survival were determined by stepwise logistic regression analysis.

RESULTS

At least one patent or stenosed graft to the left anterior descending artery was present in 50% of patients, to the circumflex territory in 27% of patients, and to the right coronary artery territory in 33% of patients. The previous left anterior descending graft was a saphenous vein in 82% and a left internal thoracic artery in 18% of patients. In-hospital mortality occurred in 42 (5.6%) patients. Patent or diseased grafts of any coronary artery territory did not significantly increase the risk of mortality. Retrograde cardioplegia use increased in more recent years, was more frequent in patients with stenosed grafts, and was associated with improved survival. Independent predictors of mortality were as follows (with odds ratios and 95% confidence intervals in parentheses): failure to use retrograde cardioplegia (odds ratio 2.81; 1.28-6.20), New York Heart Association class (odds ratio 2.69; 1.25-5.81), peripheral vascular disease (odds ratio 2.60; 1.25-5.41), and left ventricular grade (2.07; 1.31-3.27).

CONCLUSIONS

In this series, patent or stenosed grafts were not associated with an increased risk of mortality during reoperative coronary bypass surgery, possibly because of increased use of retrograde cardioplegia in this patient group. We strongly recommend the routine use of retrograde cardioplegia during redo coronary bypass surgery.

Fast-track cardiac anaesthesia in the elderly: effect of two different anaesthetic techniques on mental recovery

Elderly patients may be considered for 'fast-track' cardiac anaesthesia, but can suffer psychological complications and slow recovery of mental function after surgery, which can interfere with recovery. Reduced metabolism and changed distribution of anaesthetic and sedative agents can cause poor recovery. We made a prospective randomized comparison of mental function, haemodynamic stability and extubation and discharge times in elderly patients (65-79 yr) receiving two premedication, anaesthetic and sedative techniques. Patients received either propofol (n=39) (fentanyl 10-15 microg kg(-1) and propofol 2-6 mg kg(-1) intraoperatively and a propofol infusion for 3 h postoperatively) or premedication with lorazepam followed by midazolam for anaesthesia (n=39) (fentanyl 10-15 microg kg(-1) and midazolam 0.05-0.075 mg kg(-1) intraoperatively and a midazolam infusion for 3 h postoperatively). Impairment of mental function was noted in 41% of patients in the propofol group and 83% in the lorazepam and midazolam group (P=0.001) 18 h after extubation. Patients in the propofol group were extubated earlier [1.4 (SD 0.6) vs 1.9 (0.8) h, P=0.02]; and reached standard intensive care unit discharge criteria [7.6 (4.6) vs 14.2 (13) h, P=0.02] and hospital discharge criteria [4.3 (1.0) vs 4.9 (1.1) days, P=0.04) sooner than patients in the lorazepam and midazolam group, but actual discharge times did not differ between the groups. Haemodynamic values were stable in both groups.

Morbid results of prolonged intubation after coronary artery bypass surgery

OBJECTIVES

This study evaluated the morbid results of prolonged intubation after coronary artery bypass grafting (CABG).

METHODS

Over 30 months, 66 of 1,112 patients undergoing CABG required prolonged intubation. They were matched with 66 patients who did not require prolonged intubation. Preoperative and operative variables were evaluated to determine which would predict prolonged intubation. The postoperative courses were then compared to evaluate the effect of prolonged intubation. The study population was divided into three groups: those who underwent early extubation, but required reintubation (n = 24); those who required initial prolonged intubation, but no reintubation (n = 22); and those who required initial prolonged intubation and reintubation (n = 20).

RESULTS

Univariate analysis revealed unstable angina (p = 0.037), elevated creatinine (p = 0.001), reduced FEV(1) (p = 0.019), longer cardiopulmonary bypass time (p = 0.009), and a greater positive fluid balance at 24 h (p = 0.0001) as predictors of postoperative prolonged intubation. Multivariate regression analysis revealed elevated creatinine (p = 0.011), FEV(1) (p = 0.022), and fluid balance (p = 0.001) as predictors of prolonged intubation. The study population had longer ICU and hospital stays (p = 0.0001), with more infectious complications (p = 0.0001) and higher mortality (p = 0. 001). In the subgroups of the study population, patients not requiring reintubation had shorter ICU (p = 0.001) and hospital stays (p = 0.0001), fewer infectious complications (p = 0.0001), and reduced mortality (p = 0.0001).

CONCLUSIONS

Patients undergoing CABG with reduced FEV(1), renal failure, and positive fluid balance 24 h postoperatively are at risk for prolonged intubation. Prolonged intubation results in significant acute and midterm morbidity and mortality. Early extubation followed by reintubation further increases morbidity and mortality rates in these patients.