Inhalation-based anesthetic techniques are the key to early extubation of the cardiac surgical patient

Clinical practice of early extubation after liver transplantation

BACKGROUND

Anesthetic practices such as early tracheal extubation facilitate postoperative recovery. Early extubation after liver transplantation has been adopted by some centers in the recent two decades. No universal clinical guidelines are used and questions remain. This review aimed to address the current status of early extubation after liver transplantation.

DATA SOURCES

A literature search of MEDLINE and ISI Web of Knowledge databases was performed using terms such as liver transplantation, early extubation, immediate tracheal extubation, fast tracking or fast track anesthesia and postoperative tracheal extubation. Additional papers were identified by a manual search of the references in the key articles.

RESULTS

Review of the available literature provided an insight into the definition, evolution, advantages and risks of early extubation, and anesthetic techniques that prompt early extubation in liver transplant patients. Early extubation has proved to be feasible and safe in these patients, but the outcomes are still uncertain.

CONCLUSIONS

Early extubation after liver transplantation is feasible, safe and cost-effective in the majority of patients and has been increasingly accepted as an option for conventional postoperative ventilation. Comprehensive and individualized evaluation of the patient's condition before extubation by an experienced anesthesiologist is the cornerstone of success. Understanding of its effect on the outcome remains incomplete. In the future, additional trials are required to establish universal early extubation guidelines and to determine its benefits for patients and practitioners.

ICU Cutilization by Cardio-Thoracic Patients in a Nigerian Teaching Hospital: Any Role for HDU?

Background:

The underlying pathological conditions in cardio-thoracic patients, anesthetic and operative interventions often lead to complex physiological interactions that necessitate ICU care. Our objectives were to determine the intensive care unit (ICU) utilization by cardio-thoracic patients in our centre, highlight the common indications for admission; and evaluate the interventions provided in the ICU and the factors that determined outcome.

Materials and Methods:

The intensive care unit (ICU) records of University College Hospital, Ibadan for a period of 2 years (October 2007 to September 2009) were reviewed. Data of cardio-thoracic patients were extracted and used for analysis. Information obtained included the patient demographics, indications for admission, interventions offered in the ICU and the outcome.

Results:

A total of 1, 207 patients were managed in the ICU and 206 cardio-thoracic procedures were carried out during the study period. However, only 96 patients were admitted into the ICU following cardio-thoracic procedures, accounting for 7.9% of ICU admissions and 46.6% of cardio-thoracic procedures done within the review period. The mean length of stay and ventilation were 5.71 ± 5.26 and 1.30 ± 2.62 days. The most significant predictor of outcome was endotracheal intubation (P = 0.001) and overall mortality was 15%.

Conclusion:

There is a high utilization of the ICU by cardio-thoracic patients in our review and post-operative care was the main indication for admission. Some selected cases may be managed in the HDU to reduce the burden on ICU resources. We opine that when endotracheal intubation is to continue in the ICU, a 1:1 patient ratio should be instituted.

Early extubation in tetralogy of Fallot patients after complete repair

AIM

To document the feasibility of early extubation and to know the effect of age, weight, and post-operative right ventricle/left ventricle ratio in early extubation in intracardiac repair for tetralogy of Fallot.

MATERIALS AND METHODS

This is a prospective study of 76 consecutive patients undergoing intracardiac repair between January, 2010 and April, 2010. The patients were compared between duration of ventilation with age, weight, and post-operative left ventricle/right ventricle ratio.

RESULTS

In the age group less than 10 years, 47 patients were extubated within 4 hours and 12 after 4 hours. In the age group of 10-20 years, eight patients were extubated within 4 hours and seven patients after 4 hours. In the more than 20 years category, one patient was extubated within 4 hours and the other after 4 hours. In the weight category less than 10 kilograms, 17 patients were extubated within 4 hours and seven patients after 4 hours. In the 10-20 kilogram category, 27 patients were extubated before 4 hours and four patients after 4 hours. In the more than 20-kilogram category, 12 patients were extubated before 4 hours and nine patients after 4 hours. Where the ratio was less than 0.5, 47 patients were extubated within 4 hours and 14 patients after 4 hours. Where the ratio was greater than 0.5, nine patients were extubated within 4 hours and six patients after 4 hours.

CONCLUSION

There was no correlation between duration of ventilation with age, weight, and right ventricle/left ventricle ratio. Early extubation in patients after intracardiac repair in tetralogy of Fallot is safe and effective.

Immediate extubation versus standard postoperative ventilation: Our experience in on pump open heart surgery

Elective postoperative ventilation in patients undergoing "on pump" open heart surgery has been a standard practice. Ultra fast-track extubation in the operating room is now an accepted technique for "off pump" coronary artery bypass grafting. We tried to incorporate these experiences in on pump open heart surgery and compare the haemodynamic and respiratory parameters in the immediate postoperative period, in patients on standard postoperative ventilation for 8-12 hours. After ethical committee's approval and informed consent were obtained, 72 patients, between 28 and 45 years of age, undergoing on pump open heart surgery, were selected for our study. We followed same standard anaesthetic, cardiopulmonary bypass (CPB) and cardioplegic protocol. Thirty-six patients (Group E) were randomly allocated for immediate extubation following operation, after fulfillment of standard extubation criteria. Those who failed to meet these criteria were not extubated and were excluded from the study. The remaining 36 patients (Group V) were electively ventilated and extubated after 8-12 hours. Standard monitoring for on pump open heart surgery, including bispectral index was done. The demographic data, surgical procedures, preoperative parameters, aortic cross clamp and cardiopulmonary bypass times were comparable in both the groups. Extubation was possible in more than 88% of cases (n=32 out of 36 cases) in Group E and none required reintubation for respiratory insufficiency. Respiratory, haemodynamic parameters and postoperative complications were comparable in both the groups in the postoperative period. Therefore, we can safely conclude that immediate extubation in the operating room after on pump open heart surgery is an alternative acceptable method to avoid postoperative ventilation and its related complications in selected patients.

Combination of Intrathecal Morphine and Remifentanil Infusion for Fast-Track Anesthesia in Off-Pump Coronary Artery Bypass Surgery

OBJECTIVE

The purpose of this study was to assess the combination of intrathecal morphine and remifentanil infusion with isoflurane in off-pump coronary artery surgery, with a focus on postoperative analgesia and fast-tracking.

DESIGN

Prospective, randomized, controlled, blinded clinical study.

SETTING

University hospital.

PARTICIPANTS

Forty-six patients who underwent elective off-pump coronary artery bypass grafting.

INTERVENTIONS

Patients were randomly assigned to receive remifentanil infusion alone (control group, n = 23) or remifentanil infusion plus 10 microg/kg of intrathecal morphine (ITM group, n = 23). Induction and maintenance anesthesia were the same in both groups. Maintenance therapy was remifentanil infusion (0.25-1 microg/kg/min) and 0.5% to 1.5% isoflurane, with adjustments according to hemodynamics. After extubation, intravenous patient-controlled analgesia with morphine (1-mg bolus and 5-minute lockout) was administered, and Wilson sedation scores, visual analog pain scores (scale, 0-100 mm) at rest and during coughing, and cumulative morphine consumption were assessed at 1, 2, 4, 8, 12, 24, and 48 hours. Examiners were unaware of patients' group identities. Anesthetic recovery parameters and opioid-related, spinal anesthesia-related, and cardiac complications were recorded.

MEASUREMENTS AND MAIN RESULTS

There were no differences between the groups' intraoperative hemodynamic or anesthetic recovery findings. Pain scores and morphine consumption were significantly lower in the ITM group at all time points after extubation (p = 0.0001-0.05). Group frequencies of opioid-related and cardiac complications were similar. No patient had central neuroaxial hematoma or post-spinal tap headache.

CONCLUSION

In the setting of isoflurane anesthesia for off-pump coronary artery bypass grafting, ITM combined with remifentanil infusion provides better postoperative analgesia than does remifentanil infusion alone, and does not improve or negatively affect fast-tracking.

Evidence-based practice - an incomplete model of the relationship between theory and professional work

RATIONALE, AIMS AND OBJECTIVES

Current day realities of diminishing resources, reductions in spending and organizational change within health care systems have resulted in an increased emphasis on a multidisciplinary team approach to quality patient care. The movement of nursing towards more autonomous practice combined with the current trend towards 'evidence-based practice' in health care demands increased accountability in clinical decision making. This paper focuses on one aspect of nurses' clinical decision making within the demands of evidence-based practice and cardiac surgery. In this field recent advances, combined with increasing demands on health care institutions, have promoted early extubation of post-operative cardiac patients. While this remains a medical role in many institutions, an increasing number of intensive care units now consider it as a nursing role.

METHOD

This paper explores the realities of nurses' clinical decision making through a discussion of current practice in the extubation of patients following cardiac surgery. In addition, it considers the implications of current practice for both nurse education and the continued development of clinical nursing practice.

CONCLUSION

The findings indicate that evidence-based practice appears to be an incomplete model of the relationship between theory and professional work.

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.

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.

The lack of benefit of tracheal extubation in the operating room after coronary artery bypass surgery

Although early tracheal extubation in cardiac anesthesia is safe and cost beneficial, questions still remain regarding how early after cardiac surgery patients should be tracheally extubated (TE). Our objective was to determine the effects on resource use if patients scheduled for coronary artery bypass grafting have TE in the operating room (OR). We studied 100 consecutive patients undergoing elective coronary artery bypass grafting, requiring extracorporeal circulation, and those eligible for a fast-track pathway. At the end of the procedure, the patients were evaluated for TE in the OR if they were hemodynamically stable, were without significant bleeding, and fulfilled clinical and blood gas analysis variables. Patients who did not meet the requirements had TE in the intensive care unit (ICU). Fifty patients had TE in the OR and 50 patients in the ICU. Time in the OR after skin closure, ICU length of stay, and postoperative length of stay were similar between the groups. Four patients (8%) in the OR group were tracheally reintubated secondary to respiratory depression (P = 0.11). Three patients (6%) in the OR group had postoperative myocardial infarction, and one postoperative myocardial infarction (2%) occurred in the ICU group (P = 0.61). All four patients recovered satisfactorily. The incidences of other complications were similar between groups.

Fast-track cardiac anesthesia: use of remifentanil combined with intrathecal morphine as an alternative to sufentanil during desflurane anesthesia

The purpose of this cardiac fast-track study was to evaluate the use of remifentanil (R) combined with intrathecal (IT) morphine as an alternative to sufentanil (S) during desflurane anesthesia with respect to postoperative pain control. Prior to entering the operating room, patients in the R group (n = 20) received morphine, 8 microg/kg IT. Anesthesia was induced using a standardized anesthetic technique in all patients. In the R group, anesthesia was maintained with R, 0.1 microg. kg(-1). min(-1) in combination with desflurane 3-10%. In the S group (n = 20), patients received S 0.3 microg. kg(-1). h(-1) and desflurane 3-10%. There were no differences between the two groups with respect to time from arrival in the intensive care unit to tracheal extubation (5.1 +/- 4.3 h vs 5.8 +/- 6.7 h for R and S groups, respectively). After extubation, patients in the R group had significantly lower visual analog pain scores, reduced patient-controlled analgesic requirements, and greater satisfaction with their perioperative pain management, compared with patients in the S group. We conclude that R combined with IT morphine provided superior pain control after cardiac surgery compared with a S-based general anesthetic technique.

IMPLICATIONS

As part of a cardiac fast-tracking program involving desflurane anesthesia, the use of intrathecal morphine in combination with a remifentanil infusion provided improved postoperative pain control, compared with IV sufentanil alone.

Routine immediate extubation after cardiac operation: a review of our first 100 patients

BACKGROUND

Early extubation after cardiac operation is an important aspect of fast-track cardiac anesthesia. Immediate extubation is an extension of this concept. We describe a technique that allows immediate extubation in the majority of patients.

METHODS

To allow rapid emergence, anesthesia was modified from a high-dose opioid technique to intravenous propofol anesthesia supplemented with sevoflurane. Normothermic cardiopulmonary bypass was used with routine intermittent antegrade and retrograde tepid blood cardioplegia. High thoracic epidural analgesia was used to facilitate immediate extubation in the majority of patients. Contraindications to immediate extubation were prolonged cardiopulmonary bypass (CPB) (>2.5 hours), hemodynamic instability, uncontrolled bleeding, morbid obesity, severe pulmonary hypertension, congestive cardiac failure, or if the operation was emergent.

RESULTS

Of 109 consecutive patients, 100 were immediately extubated (92%). No patient required reintubation within the first 24 hours after operation. One patient required reintubation 3 days after operation for sputum retention, and 2 patients required reoperation. There was no mortality and the incidence of perioperative morbidity was low.

CONCLUSIONS

Immediate extubation after cardiac operation can be safely achieved and is possible in a majority of patients.

Influence of fast-track anesthetic technique on cardiovascular infusions and weight gain

OBJECTIVE

To evaluate whether cardiac surgical patients receiving conventional versus fast-track anesthetic management are statistically significantly different with regard to cardiovascular drug infusions, weight gain, cardiac and pulmonary morbidity, length of intubation, and length of stay.

DESIGN

Retrospective, (partially) sequential, cohort design.

SETTING

Surgical suite and intensive care unit (ICU) at a community hospital.

PARTICIPANTS

Two hundred seven patients who presented for coronary artery bypass graft and/or cardiac valve replacement.

INTERVENTIONS

None

MEASUREMENTS AND MAIN RESULTS

Group comparisons of the seven individual cardiovascular drug infusions showed less frequent use in the fast-track patients for lidocaine (9% v 28%; p = 0.00046) only. However, the fast-track group received fewer combinations of cardiovascular drug infusions overall for the first 24-hour postoperative period (p < 0.0005). Hourly comparisons of inotropes showed significantly fewer combinations of dobutamine, norepinephrine, and epinephrine for the first postoperative hour and for postoperative hours 7 through 12 (p < 0.01 for each hour). Fast-track patients had less postoperative weight gain for days 1 through 4 (p < 0.01 for each day), shorter length of ICU stay (p < 0.00005), and shorter total length of postoperative hospital stay (p = 0.0004). No differences were found with respect to myocardial infarction, death, pulmonary complications, rate of reintubation, or length of hospital stay once discharged from the ICU.

CONCLUSIONS

Fast-track anesthetic management may be associated with decreased need for inotropic and antiarrhythmic drug infusions and decreased weight gain.

Who goes to the ICU postoperatively?

OBJECTIVE

To describe changes in ICU postoperative management strategies utilized for patients undergoing cardiac surgery. The treatment of these patients serves as a useful illustration of the changing patterns of ICU utilization and care associated with contemporary surgery.

DESIGN

Evidence-based review of the clinical literature following a MEDLINE search, direct observation of rapid recovery programs following surgery, and informal inquiry of others utilizing similar approaches to postoperative cardiac surgery care.

SETTING AND PATIENTS

The reports reviewed are from a diverse set of hospitals providing cardiac surgery services in both Europe and the United States. Most reports focus efforts on patients undergoing coronary artery revascularization.

MEASUREMENTS

Outcome measures used to gauge the effectiveness of postoperative ICU care typically include time to extubation, ICU and hospital length of stay, postoperative complications including reintubation and ICU readmission, patient satisfaction, and health resource savings.

MAIN RESULTS

The literature regarding current practice for postoperative ICU management in cardiac surgery consists primarily of grade 2 and 3 literature.

CONCLUSIONS

Despite the paucity of controlled data, rapid recovery, extubation, and discharge from the ICU following cardiac surgery is an approach to care that is growing in acceptance. The goals include reduction in the utilization of resources and costs associated with cardiac surgery and maintenance of quality of care and patient satisfaction. Assessment of outcomes requires a program to monitor outcomes. Success does not appear to be linked to preoperative risk for most patients but does relate directly to the anesthetic management delivered in the operating room. Few adverse consequences from this approach have been reported. Experience to date suggests that programs designed to truncate ICU admission following cardiac surgery can be implemented with the cooperation between the health delivery team including surgeon, anesthesiologist, intensivist where available, nursing, respiratory care, and patient and family. These programs can serve as useful models for reassessing the utilization and role of the ICU in the postoperative treatment of routine surgical patients.

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

OBJECTIVE

To evaluate drug costs, time of mechanical ventilation, complications, and hospital length of stay comparing propofol-based with fentanyl-isoflurane-based anesthesia.

DESIGN

A prospective, randomized study.

SETTING

A university-affiliated, tertiary care community hospital.

PARTICIPANTS

Seventy patients undergoing primary coronary artery bypass surgery.

INTERVENTIONS

Patients were randomized to either a low-dose fentanyl-isoflurane or a lower-dose fentanyl-isoflurane anesthetic supplemented with a continuous infusion of propofol.

MEASUREMENTS AND MAIN RESULTS

Fentanyl-isoflurane anesthesia was significantly less expensive ($50.03+/-$27.26 v $121.69+/-$31.40) for anesthesia drugs and ($58.08+/-$27.39 v $129.91+/-$31.52) for total drug costs. There was also a trend for patients in the fentanyl-isoflurane group to be extubated slightly sooner (388+/-202 v 449+/-252 min) and go home sooner (5.1+/-1.8 v 6.0+/-3.0 days).

CONCLUSION

Fentanyl-isoflurane provides an inexpensive anesthetic that permits as prompt an extubation as propofol, thus conserving resources for other patients.

Early vs conventional extubation after cardiac surgery with cardiopulmonary bypass

OBJECTIVES

Sedation and ventilation overnight after cardiac surgery is common practice. However, early extubation may be feasible with no increase in postoperative complications. This study examines (1) if early extubation is possible in a significant number of patients, (2) if it reduces ICU stay, and (3) if this practice increases postoperative complications.

DESIGN

Prospective, controlled, randomized clinical trial.

PATIENTS AND METHODS

We randomized 404 consecutive patients to early extubation (7 to 11 h postoperatively) (group A, 201 patients) or conventional extubation (between 8 and 12 AM the following day) (group B, 203 patients). Variables included type and severity of the disease, surgical risk, type of operation, operative incidences, postoperative complications, duration of mechanical ventilation, intubation and ICU stay, bleeding, reoperation, vasoactive drugs, and mortality.

RESULTS

Groups were comparable. Extubation within the preestablished time was successful in 60.2% of patients in group A and 74.4% in group B. Median ICU stay was 27 h in group A and 44 h in group B (p=0.008). Discharge from ICU within the first 24 h postoperatively was 44.3% in group A and 30.5% in group B (p=0.006). There was no significant difference in complications between groups. Successfully extubated patients in group A had more reintubation and prolonged ventilation than in group B.

CONCLUSIONS

(1) Sixty percent of our patients were extubated within 11 h of operation. (2) As a result, the length of stay in ICU was reduced and the percentage of patients discharged within 24 h was increased. (3) There was no increase in clinically important postoperative complications.

Fast-track cardiac surgery in a Department of Veterans Affairs patient population

BACKGROUND

"Fast-track" (FT) cardiac surgery is popular in the private and university sectors. This study was designed to examine its safety and efficacy in the Department of Veterans Affairs elderly, male patient population, a population with multiple comorbid risk factors, often decreased social functioning, and impaired support systems.

METHODS

Time to extubation, hospital length of stay, perioperative morbidity, and mortality were studied in two consecutive cohorts undergoing cardiac operations requiring cardiopulmonary bypass before (pre-FT: n = 255, January 1992 to September 1993) and after (FT: n = 304, October 1993 to October 1995) institution of an FT protocol at a university-affiliated teaching Department of Veterans Affairs medical center. Preoperative risk factors, including a Department of Veterans Affairs risk-adjusted estimate of operative mortality, and perioperative surgical and anesthetic processes of care were evaluated.

RESULTS

The mean Department of Veterans Affairs risk estimate of perioperative mortality was not different between the pre-FT and FT cohorts (3.5% versus 3.7%, p = 0.13). In the FT cohort, median time to extubation decreased significantly (19.2 versus 10.2 hours; p < 0.001) along with median surgical intensive care unit stay (96 versus 49 hours; p < 0.001) and total postoperative length of stay (222 versus 167 hours; p < 0.001). Median postoperative day of hospital discharge decreased from day 10 to 7 (p < 0.001). One patient (0.3%) required emergent reintubation directly related to early extubation. Reintubation for medical reasons was unchanged between pre-FT and FT groups (6.3% versus 5.0%; p = 0.48). Postoperative morbidity was similar between groups except for nosocomial pneumonia, the rate of which decreased significantly in the FT cohort (14.7% versus 7.3%; p < 0.005). Thirty-day (3.9% versus 4.6%; p = 0.69) and 6-month mortality (6.7% versus 6.9%; p = 0.91) were unchanged.

CONCLUSIONS

An FT cardiac surgery protocol has been instituted in a university-affiliated teaching Department of Veterans Affairs medical center, with decreased length of stay and no significant increase in postoperative morbidity, 30-day mortality, or 6-month mortality. It was associated with a lower rate of nosocomial pneumonia, a finding that must be validated in a prospective study.

Early extubation after mitral valve surgery: a target-controlled infusion of propofol and low-dose sufentanil

OBJECTIVE

In the current study, the use of a target-controlled infusion of low-dose propofol was combined with a continuous infusion of sufentanil for patients undergoing mitral valve surgery. The purpose of the study was to evaluate the hemodynamic stability, the time to awakening and spontaneous ventilation, and the feasibility in an early extubation setting of a total intravenous anesthetic technique.

DESIGN

Prospective study.

SETTING

University hospital.

PARTICIPANTS

Fifteen patients scheduled for elective mitral valve surgery.

INTERVENTIONS

Induction of anesthesia consisted of sufentanil (1 microgram/kg), propofol (1 microgram/mL) target plasma concentration achieved over 3 minutes, and atracurium (0.5 mg/kg). The propofol target-controlled infusion was maintained at 1 microgram/mL throughout surgery and stopped at skin closure. A continuous infusion of sufentanil at 1.8 micrograms/kg/hr was started after induction and reduced to 0.9 microgram/kg/hr at the start of cardiopulmonary bypass and stopped at the end of bypass. Atracurium was infused at a rate of 0.5 mg/kg/hr up to sternal closure. No inhalation agents were used.

MEASUREMENTS AND MAIN RESULTS

Hemodynamic data were within normal limits. Six patients (40%) responded to verbal commands within 15 minutes postoperatively, 10 (67%) within the first hour, and all patients recovered within 2 hours. Four patients (27%) resumed spontaneous ventilation within the first 15 postoperative minutes. The time to successful spontaneous ventilation was 169 +/- 42 minutes. Spontaneous ventilation was associated with a 21% increase in cardiac index. Total sufentanil dose was 328 +/- 28 micrograms (4.6 +/- 0.2 microgram/kg), whereas total propofol dose was 862 +/- 44 mg (13.1 +/- 1.2 mg/kg). No patient required reintubation.

CONCLUSION

The simplicity of the method with only one change in infusion rate is a major advantage. The technique permits predictable recovery and return to spontaneous ventilation in all patients. Its use in patients entering early extubation protocols is appealing for its reproducibility, simplicity, and safety.

Hemodynamic effects, myocardial ischemia, and timing of tracheal extubation with propofol-based anesthesia for cardiac surgery

Recent interest in earlier tracheal extubation after coronary artery bypass graft (CABG) surgery has focused attention on the potential benefits of a propofol-based technique. We randomized 124 patients (34 with poor ventricular function) undergoing CABG surgery to receive either a propofol-based (5 mg.kg-1.h-1 prior to sternotomy, 3 mg.kg-1. h-1 thereafter; n = 58) or enflurane-based (0.2%-1.0%, n = 66) anesthetic. Induction of anesthesia consisted of fentanyl 15 micrograms/kg and midazolam 0.05 mg/kg intravenously in both groups. The enflurane group received an additional bolus of fentanyl 5 micrograms/kg prior to sternotomy and fentanyl 10 micrograms/kg with midazolam 0.1 mg/kg at commencement of cardiopulmonary bypass (CPB). Patients receiving propofol were extubated earlier (median 9.1 h versus 12.3 h, P = 0.006), although there was no difference in time to intensive care unit (ICU) discharge (both 22 h, P = 0.54). Both groups had similar hemodynamic changes throughout (all P > 0.10), as well as metaraminol (P = 0.49) and inotrope requirements (P > 0.10), intraoperative myocardial ischemia (P = 0.12) and perioperative myocardial infarction (P = 0.50). The results of this trial suggest that a propofol-based anesthetic, when compared to an enflurane-based anesthetic requiring additional dosing of fentanyl and midazolam for CPB, can lead to a significant reduction in time to extubation after CABG surgery, without adverse hemodynamic effects, increased risk of myocardial ischemia or infarction.

Propofol-alfentanil versus fentanyl-midazolam in coronary artery surgery

OBJECTIVE

To compare intraoperative hemodynamics profiles and recovery characteristics of propofol-alfentanil with fentanyl-midazolam anesthesia in elective coronary artery surgery.

DESIGN

Prospective, randomized study.

SETTING

University hospital.

PARTICIPANTS

Fifty patients with impaired or good left ventricular function.

INTERVENTIONS

In group 1, (n = 25) anesthesia was induced with an infusion of propofol, 3 to 4 mg/kg/h, alfentanil, 500 micrograms, and pancuronium 0.1 mg/kg, and maintained with propofol, 3 to 6 mg/kg/h (variable rate), and alfentanil infusions, 30 micrograms/kg/h (fixed rate). Additional boluses of alfentanil, 1 mg, were administered before noxious stimuli; group 2 (n = 25) received a loading dose of fentanyl, 25 micrograms/kg, midazolam, 1.5 to 3 mg, and pancuronium, 0.1 mg/kg for induction, followed by an infusion of fentanyl, 7 micrograms/kg/h, for maintenance. Additional boluses of midazolam (1.5 to 3 mg) and fentanyl (250 micrograms) were administered before noxious stimuli. MEASUREMENTS AND MAIN RESULTS. Cardiovascular parameters at eight intraoperative time points as well as time to extubation, morphine consumption, and pain scores were recorded. Induction of anesthesia was associated in both groups with a small but significant decrease in mean arterial pressure (1: 15 mmHg (15%); 2: 8 mmHg (8%) with significant decreases in cardiac index (1: 8%; 2: 8%) and left ventricular stroke work index (1: 24%; 2: 21%). Throughout surgery, hemodynamic profiles were comparable between groups except after intubation when the MAP was significantly lower in group 1 (75 +/- 12 mmHg) than in group 2 (89 +/- 17 mmHg). Group 1 required less inotropic support. Extubation was performed faster in group 1 (7.6 h) than in group 2 (18.0 h). Morphine requirements and pain scores were comparable between groups.

CONCLUSIONS

Propofol-alfentanil anesthesia provides good intraoperative hemodynamics and allows early extubation after coronary artery surgery.

Determinants of prolonged mechanical ventilation after coronary artery bypass grafting

BACKGROUND

Early extubation of cardiac surgical patients enhances ambulation, improves cardiopulmonary function, and can lead to savings in health care costs.

METHODS

We retrospectively examined the role of 48 variables in determining the period of ventilatory support in 507 patients having coronary artery bypass grafting.

RESULTS

Fifteen (< 3%) of 507 patients required ventilatory support in excess of 24 hours. Among the remaining patients, extubation was achieved early (< or = 8 hours) (mean time, 5.65 +/- 1.31 hours) in 53% and late (> 8 hours) (mean time, 13.7 +/- 3.4 hours) in 47%. Logistic and linear multivariate regression analyses implicated increased age, New York Heart Association functional class IV, intraoperative fluid retention, postoperative intraaortic balloon pump requirement, and bank blood transfusions as predictors of late extubation. Also, the linear regression linked lower body weight and number of anastomoses (or grafts) to increased mechanical ventilatory support.

CONCLUSIONS

Analysis of the fluid balance and cardiopulmonary bypass data suggests that earlier extubation may be achieved by actively reducing fluid retention (eg, by hemoconcentration) and time on bypass (eg, normothermia). Finally, intensive care unit stay and postoperative length of stay were significantly lower in the early versus late extubation groups without an increase in pulmonary complications.

The effects of anesthetic technique on the hemodynamic response and recovery profile in coronary revascularization patients

This study was undertaken to assess the effects of propofol (versus enflurane, fentanyl, and thiopental) on hemodynamic stability and recovery characteristics when used for maintenance of anesthesia during elective coronary artery bypass grafting (CABG) procedures. Ninety premedicated patients scheduled for elective coronary revascularization had anesthesia induced with fentanyl 25 micrograms/kg intravenously (i.v.). When the mean arterial blood pressure (MAP) increased 10% above preoperative baseline values, patients were randomized to receive one of four anesthetic treatments: enflurane, 0.25-2.0%; fentanyl, 10-20 micrograms/kg i.v. bolus doses; propofol, 50-250 micrograms.kg-1.min-1 i.v.; or thiopental, 100-750 micrograms.kg-1.min-1 i.v.. The maintenance anesthesia was titrated to achieve hemodynamic stability (i.e., maintain the MAP within 10% of the baseline values and heart rate [HR] within 20% of the baseline values). After bypass, anesthetic and cardiovascular drugs were titrated to maintain the MAP > 65 mm Hg and the cardiac index (CI) > 2.3 L.min-1.m-2. Recovery was assessed by noting the times at which patients first opened their eyes, responded to verbal communication, correctly responded to specific commands, underwent tracheal extubation, and were discharged from the intensive care unit (ICU). Although less intraoperative hypertension was noted in the propofol-treated patients (19 +/- 11 min vs 38 +/- 26 min, 30 +/- 24 min, and 30 +/- 23 min in the enflurane, fentanyl, and thiopental groups, respectively) (P = 0.04), the incidence of hypotension did not differ significantly among the groups. Vasopressor drugs were required more often during the prebypass period in fentanyl and propofol patients (4/22 and 5/23, respectively) compared to the thiopental group (0/21) (P < 0.05). During CPB, fentanyl-treated patients required vasoconstrictors more often than patients in the other three treatment groups (14/22 vs 6/24, 4/23, and 5/21 in the enflurane, propofol, and thiopental groups, respectively) (P < 0.01). Although fentanyl-treated patients had significantly greater requirements for inotropic support during weaning from CPB than propofol-treated patients (14/22 vs 7/23) (P < 0.038), there were no significant differences among the groups in the postbypass or ICU periods. Propofol-treated patients responded to verbal stimuli (2.1 +/- 1.3h vs 4.0 +/- 3.5h, 4.7 +/- 2.7h, and 5.6 +/- 3.6h in the enflurane, fentanyl, and thiopental groups, respectively) (P = 0.01) and followed commands earlier (propofol 7.3 +/- 5.2h vs enflurane 12.5 +/- 5.7h, fentanyl 13.1 +/- 6.6h, and thiopental 12.8 +/- 6.7 h) (P = 0.01).(ABSTRACT TRUNCATED AT 400 WORDS)

Fast-track care after cardiac surgery

This article explains the rationale for fast-track management of low-risk cardiac surgical patients and describes the selection process and care received by these patients at the Royal Brompton Hospital. A review of the fast-track audit is presented and discussed.

Serum lipid and glucose concentrations with a propofol infusion for cardiac surgery

OBJECTIVE

To document changes in serum lipids and glucose with a propofol infusion technique for cardiac surgery.

DESIGN

Prospective cohort.

SETTING

University teaching hospital.

PARTICIPANTS

22 elective cardiac surgical patients.

INTERVENTIONS

Frequent venous blood sampling.

MEASUREMENTS AND MAIN RESULTS

Serum lipids and glucose were measured at 10 time periods perioperatively, from preinduction until 4 hours post-cardiopulmonary bypass. Plasma propofol concentrations were also measured in 10 of these patients. There was a significant increase in glucose (P < 0.0005) and decreases in cholesterol (P < 0.0005), high-density lipoprotein (P = 0.004), and low-density lipoprotein (P < 0.0005); there was no significant change in triglycerides (P = 0.39). The propofol infusion resulted in acceptable plasma levels throughout the procedure and allowed early extubation in the intensive care unit, after a mean (SD) of 7.14 (5.9) hours. There was a strong correlation between triglyceride and propofol levels at most time periods (r = 0.38 to 0.98).

CONCLUSIONS

This study demonstrates that a propofol infusion technique does not result in elevation of serum lipids and supports its increased popularity in maintenance of anesthesia for cardiac surgery.

Pro: early extubation after cardiac surgery decreases intensive care unit stay and cost

The recurrent or new trends of early extubation after cardiac surgery are here to stay in the 1990s. The preoperative status does not necessarily predict the postoperative course and prolonged mechanical ventilation following cardiac surgery should not be uncritically considered as routine. All patients should be assessed for tracheal extubation at the earliest opportunity when the criteria are met in the ICU. Early extubation post-cardiac surgery does reduce ICU and hospital length of stay and costs. It also allows early ICU discharge and reduces case cancellations without any increase in postoperative complications and readmission. These studies have emphasized that the change in the process of care to early extubation can affect patient outcome as well as costs in cardiac patient care. The substantial difference in cost savings per cardiac case between "criteria discharge" and "actual discharge" points out the importance of the organization of the process of care being delivered. To achieve maximum cost benefit from early extubation in cardiac patients, the organization of the perioperative management of these patients must be optimized. This process of care includes intraoperative anesthetic modification; organization of ICU and staff expertise; postoperative early extubation and management; acute pain service; ICU discharge policy; utilization of step-down unit and surgical ward; and communication among cardiac patient management teams (cardiovascular surgeon, cardiac anesthesiologist, ICU staff, nurses, respiratory therapists, physiotherapists, and social workers), which are all vital to the success of such a program.

Timing of tracheal extubation in adult cardiac surgery patients

In this article, we examine 14 studies conducted from 1974 to 1994 on "early" endotracheal extubation (0 to 12 hours postoperatively) in adult cardiac surgery patients. Aspects reviewed include: criteria for patient selection; criteria for extubation; analyses of feasibility and safety; effects of anesthetic technique; and patient morbidity. Advantages and disadvantages of early or "fast-track" extubation are discussed as are directions for future research. Selection criteria varied among studies; patients were most commonly excluded because of severe, preexisting pulmonary disease or ventricular dysfunction. Based on the studies examined, however, at least 70% to 80% of adult patients would meet selection criteria. Three universal criteria were applied in all studies: (1) patient is awake and responsive; (2) adequate gas exchange while breathing spontaneously; and (3) cardiovascular stability. To facilitate early extubation in appropriately selected patients, the choice of anesthetic technique and postoperative sedation technique appears to be important. Anesthetic techniques based on inhalational anesthetic agents, supplemented by moderate doses of narcotics, are more appropriate than high-dose narcotic anesthesia for early extubation protocols. Postoperative sedation with propofol, which has a rapid offset of action, may be particularly advantageous. Every published investigation has concluded that early extubation is safe, feasible, and desirable. Morbidity and mortality have not been shown to be affected by early extubation. Anesthetic technique and the patient's medical condition are the two major factors to consider in accomplishing early extubation.

Early extubation after cardiac surgery using combined intrathecal sufentanil and morphine

The records of 10 patients who had well-preserved respiratory and ventricular function and had received 50 micrograms of sufentanil and 0.5 mg of morphine intrathecally before induction of anesthesia for cardiopulmonary bypass surgery were reviewed. Anesthesia was maintained with isoflurane and no patient received intravenous narcotics intraoperatively. Postoperative analgesic requirements were low, with 7 of 10 patients requiring no supplemental analgesic during the first 12 hours. Early extubation (within 8 hours of arrival in the intensive care unit) was possible in 8 patients; two patients remained intubated for reasons unrelated to the anesthetic technique. No patient required naloxone, reintubation, or treatment for respiratory depression. Combined intrathecal sufentanil and morphine provided conditions that allowed successful early extubation in 8 of 10 of these selected cardiac surgery patients.

Anaesthesia for coronary artery surgery--a plea for a goal-directed approach

The purpose of the current literature review was to examine whether changes in current anaesthetic techniques are warranted for patients undergoing coronary artery surgery in light of recent information presented in the literature. The objectives of a cardiac anaesthetic technique are to maintain haemodynamic stability and myocardial oxygen balance, minimize the incidence and severity of ischaemic episodes, be aware of cardiopulmonary bypass-induced pharmacokinetic changes, and facilitate early tracheal extubation if appropriate. Many techniques have been utilized. Provided attention is paid to the details of managing myocardial oxygen supply and demand, none has emerged as superior in preventing intraoperative myocardial ischaemia. Silent myocardial ischaemia (i.e., ischaemia occurring in the absence of haemodynamic aberrations) is common throughout the perioperative period and may occur even in the presence of an appropriately used anaesthetic technique. The incidence and severity appear to be greatest in the postoperative period when the effects of anaesthesia are dissipating. The use of high-dose opioid anaesthesia may no longer be the most appropriate technique to facilitate the anaesthetic objectives. The role of pain management in altering the incidence of ischaemia requires further study. Increased waiting lists for cardiac surgery and ever-diminishing resources should prompt a re-evaluation of early extubation (i.e., within eight hours) as a method of improving utilization of scarce ICU resources. It is suggested that this should be possible with currently available agents to achieve the anaesthetic objectives. Future suggestions for research in this area are made.