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

The use of intrathecal morphine in non-abdominal surgery: a scoping review

Background

Intrathecal morphine can reduce pain and opioid requirements needed for postoperative pain relief. It can potentially aid in the effectiveness of enhanced recovery protocols in non-abdominal surgery. However, concerns about side-effects may have hindered its use. This scoping review evaluates the effectiveness, appropriate dosage, and adverse effects of intrathecal morphine in non-abdominal surgery.

Methods

We systematically searched for randomised controlled trials examining the use of intrathecal morphine in non-abdominal surgery.

Results

The search identified 75 trials involving 4685 patients. We undertook a scoping review of these randomised controlled trials, including bias assessments, to comprehensively analyse the effectiveness and side-effects of intrathecal morphine. The findings indicate that intrathecal morphine reduced postoperative pain and opioid consumption after spinal surgery, thoracic surgery, and orthopaedic lower extremity surgery. However, it was associated with an increased incidence of itching, postoperative nausea and vomiting, and urinary retention, particularly in orthopaedic procedures. Delayed respiratory depression was absent with low to moderate doses (<500 μg) in the reviewed studies.

Conclusions

This review supports the effectiveness of intrathecal morphine in non-abdominal surgery. However, the benefits must be carefully weighed against potential side-effects that could lead to prolonged hospital stays.

Clinical trial registration

PROSPERO-registry CRD42021233936.

Pain management after cardiac surgery via median sternotomy: A systematic review with procedure-specific postoperative pain management (PROSPECT) recommendations

BACKGROUND

Pain after cardiac surgery via median sternotomy can be difficult to treat, and if inadequately managed can lead to respiratory complications, prolonged hospital stays and chronic pain.

OBJECTIVES

To evaluate available literature and develop recommendations for optimal pain management after cardiac surgery via median sternotomy.

DESIGN

A systematic review using PROcedure-SPECific Pain Management (PROSPECT) methodology.

ELIGIBILITY CRITERIA

Randomised controlled trials and systematic reviews published in the English language until November 2020 assessing postoperative pain after cardiac surgery via median sternotomy using analgesic, anaesthetic or surgical interventions.

DATA SOURCES

PubMed, Embase and Cochrane Databases.

RESULTS

Of 319 eligible studies, 209 randomised controlled trials and three systematic reviews were included in the final analysis. Pre-operative, intra-operative and postoperative interventions that reduced postoperative pain included paracetamol, non-steroidal anti-inflammatory drugs (NSAIDs), intravenous magnesium, intravenous dexmedetomidine and parasternal block/infiltration.

CONCLUSIONS

The analgesic regimen for cardiac surgery via sternotomy should include paracetamol and NSAIDs, unless contraindicated, administered intra-operatively and continued postoperatively. Intra-operative magnesium and dexmedetomidine infusions may be considered as adjuncts particularly when basic analgesics are not administered. It is not clear if combining dexmedetomidine and magnesium would provide superior pain relief compared with either drug alone. Parasternal block/surgical site infiltration is also recommended. However, no basic analgesics were used in the studies assessing these interventions. Opioids should be reserved for rescue analgesia. Other interventions, including cyclo-oxygenase-2 specific inhibitors, are not recommended because there was insufficient, inconsistent or no evidence to support their use and/or due to safety concerns.

Postoperative hemodynamics after high spinal block with or without intrathecal morphine in cardiac surgical patients: a randomized-controlled trial

PURPOSE

There is some evidence for the use of intrathecal morphine as a means to provide prolonged analgesia in selective cardiac surgical patients; however, the hemodynamic effects of intrathecal morphine are not well defined. This study was designed to study the effect of intrathecal morphine on hemodynamic parameters in cardiac surgery patients.

METHODS

In a prospective, double-blind study, 100 adult cardiac surgical patients were randomized to receive either intrathecal 40 mg of 0.5% hyperbaric bupivacaine alone (intrathecal bupivacaine [ITB] group, n = 50) or intrathecal 250 µg of morphine added to 40 mg of 0.5% bupivacaine (intrathecal bupivacaine and morphine [ITBM] group, n = 50). Hemodynamic data, pain scores, rescue analgesic use, spirometry, and vasopressor use were recorded every four hours after surgery for 48 hr. The primary outcome was the incidence of vasoplegia in each group, which was defined as a cardiac index > 2.2 L·min-1·m-2 with the requirement of vasopressors to maintain the mean arterial pressure > 60 mmHg with the hemodynamic episode lasting > four hours.

RESULTS

Eighty-seven patients were analyzed (ITB group, n = 42, and ITBM group, n =45). The incidence of vasoplegia was higher in the ITBM group than in the ITB group [14 (31%) vs 5 (12%), respectively; relative risk, 2.6; 95% confidence interval [CI], 1.0 to 6.6; P = 0.04]. The mean (standard deviation [SD]) duration of vasoplegia was significantly longer in the ITBM group than in the ITB group [8.9 (3.0) hr vs 4.3 (0.4) hr, respectively; difference in means, 4.6; 95% CI, 3.7 to 5.5; P < 0.001].

CONCLUSION

Intrathecal morphine added to bupivacaine for high spinal anesthesia increases the incidence and duration of vasoplegia in cardiac surgery patients.

TRIAL REGISTRATION

www.clinicaltrials.gov (NCT02825056); registered 19 June 2016.

Pregabalin Effect on Acute and Chronic Pain after Cardiac Surgery

Introduction. Pain after cardiac surgery affects long-term patient wellness. This study investigated the effect of preoperative pregabalin on acute and chronic pain after elective cardiac surgery with median sternotomy. Methods. Prospective double blind study. 93 cardiac surgery patients were randomly assigned into three groups: Group 1 received placebo, Group 2 received oral pregabalin 75 mg, and Group 3 received oral pregabalin 150 mg. Data were collected 8 hours, 24 hours, and 3 months postoperatively. Results. Patients receiving pregabalin required fewer morphine boluses (10 in controls versus 6 in Group 1 versus 4 in Group 2, p = 0.000) and had lower pain scores at 8 hours (4 versus 3 versus 3, p = 0.001) and 3 months (3 versus 2 versus 2, p = 0.000) and lower morphine consumption at 8 hours (14 versus 13 versus 12 mg, p = 0.000) and 24 hours (19.5 versus 16 versus 15 mg, p = 0.000). Percentage of patients with sleep disturbances or requiring analgesics was lower in the pregabalin group and even lower with higher pregabalin dose (16/31 versus 5/31 versus 3/31, p = 0.000, and 26/31 versus 16/31 versus 10/31, p = 0.000, resp.) 3 months after surgery. Conclusion. Preoperative oral pregabalin 75 or 150 mg reduces postoperative morphine requirements and acute and chronic pain after cardiac surgery.

Fast-Track Cardiac Anesthesia: Choice of Anesthetic Agents and Techniques

Fast-track cardiac anesthesia (FTCA) incorporates early tracheal extubation, decreased length of intensive care unit (ICU) and hospital stay, and (ideally) should avoid or reduce complications to safely achieve cost-savings. A growing body of evidence from randomized trials has identified many anesthetic interventions that can improve outcome after cardiac surgery. These include new short-acting hypnotic, opioid, and neuromuscular blocking drugs. An effective FTCA program requires the appropriate selection of suitable patients, a lowdose opioid anesthetic technique, early tracheal extubation, a short stay in the ICU, and coordinated perioperative care. It is also dependent on the avoidance of postoperative complications such as excessive bleeding, myocardial ischemia, low cardiac output state, arrhythmias, sepsis, and renal failure. These complications will have a much greater adverse effect on hospital length of stay and healthcare costs. A number of clinical trials have identified interventions that can reduce some of these complications. The adoption of effective treatments into clinical practice should improve the effectiveness of FTCA.

Regional Anesthesia in Cardiac Surgery: A Friend or A Foe?

Escalating costs and change in the profile of patients presenting for cardiac surgery requires modification of perioperative management strategies. Regional anesthesia has played an integral part of many fast-track anesthesia protocols across North America and Europe. This review suggests that for patients undergoing coronary artery bypass graft surgery, the risk-to-benefit ratio is in favor of epidural and spinal anesthesia, provided there are no specific contraindications and the guidelines for the use of regional techniques in cardiac surgery are followed. Patients managed with regional techniques seem to benefit from superior postoperative analgesia, shorter postoperative ventilation, reduced incidence of supraventricular arrhythmia, and lower rates of perioperative myocardial infarction. The results of this analysis suggest that for each episode of neurologic complication, 20 myocardial infarctions and 76 episodes of atrial fibrillation would be prevented, thus, we would consider the regional anesthesia and analgesia to be an effective strategy that improves perioperative morbidity. However, other treatment modalities such as the addition of calcium channel blockers, aspirin, and beating heart surgery, are also suggested to be beneficial in cardiac surgical patients and may impose less risk than the use of regional techniques. We believe that the results presented in this review are encouraging enough to permit continued investigation. A prospective, randomized, controlled multicenter trial needs to be adequately powered to answer important clinical questions and allow for a long-term follow-up.

Pulmonary Complications After Cardiac Surgery

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

Ultra fast-track extubation in heart transplant surgery patients

Background:

Heart transplant surgeries using cardiopulmonary bypass (CPB) typically requires mechanical ventilation in intensive care units (ICU) in post-operation period. Ultra fast-track extubation (UFE) have been described in patients undergoing various cardiac surgeries.

Aim:

To determine the possibility of ultra-fast-track extubation instead of late extubation in post heart transplant patients.

Materials and Methods:

Patients randomly assigned into two groups; Ultra fast-track extubation (UFE) group was defined by extubation inside operating room right after surgery. Late extubation group was defined by patients who were not extubated in operating room and transferred to post operation cardiac care unit (CCU) to extubate.

Results:

The mean cardiopulmonary bypass time was 136.8 ± 25.7 minutes in ultra-fast extubation and 145.3 ± 29.8 minutes in late extubation patients (P > 0.05). Mechanical ventilation duration (days) was 0 days in ultra-fast and 2.31 ± 1.8 days in late extubation. Length of ICU stay was significantly higher in late extubation group (4.2 ± 1.2 days) than the UFE group (1.72 ± 1.5 days) (P = 0.02). In survival analysis there was no significant difference between ultra-fast and late extubation groups (Log-rank test, P = 0.9).

Conclusions:

Patients undergoing cardiac transplant could be managed with “ultra-fast-track extubation”, without increased morbidity and mortality.

Epidural analgesia for cardiac surgery

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Health-related quality of life after fast-track treatment results from a randomized controlled clinical equivalence trial

PURPOSE

This randomized clinical equivalence trial was designed to evaluate health-related quality of life (HRQoL) after fast-track treatment for low-risk coronary artery bypass (CABG) patients.

METHODS

Four hundred and ten CABG patients were randomly assigned to undergo either short-stay intensive care treatment (SSIC, 8 h of intensive care stay) or control treatment (care as usual, overnight intensive care stay). HRQoL was measured at baseline and 1 month, and one year after surgery using the multidimensional index of life quality (MILQ), the EQ-5D, the Beck Depression Inventory and the State-Trait Anxiety Inventory.

RESULTS

At one month after surgery, no statistically significant difference in overall HRQoL was found (MILQ-score P-value=.508, overall MILQ-index P-value=.543, EQ-5D VAS P-value=.593). The scores on the MILQ-domains, physical, and social functioning were significantly higher at one month postoperatively in the SSIC group compared to the control group (P-value=.049; 95%CI: 0.01-2.50 and P-value=.014, 95% CI: 0.24-2.06, respectively). However, these differences were no longer observed at long-term follow-up.

CONCLUSIONS

According to our definition of clinical equivalence, the HRQoL of SSIC patients is similar to patients receiving care as usual. Since safety and the financial benefits of this intervention were demonstrated in a previously reported analysis, SSIC can be considered as an adequate fast-track intensive care treatment option for low-risk CABG patients.

Spinal analgesia in cardiac surgery: a meta-analysis of randomized controlled trials

OBJECTIVE

Controversial results exist on the effects of spinal analgesia in cardiac surgery. The authors conducted a review of randomized studies to show whether there are any advantages in clinically relevant outcomes using spinal analgesia in patients undergoing cardiac surgery.

DESIGN

Meta-analysis.

SETTING

Multiple hospitals.

PARTICIPANTS

A total of 1,106 patients from 25 randomized trials.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULT

PubMed, BioMedCentral, CENTRAL, EMBASE, Cochrane Central Register of Controlled Trials, and conference proceedings were searched (updated January 2009) for randomized trials that compared general anesthesia with an anesthetic plan including spinal analgesia in cardiac surgery. Four independent reviewers performed data extraction, with divergences resolved by consensus. A total of 1,106 patients from 25 randomized studies were included in the analysis. Overall analysis showed that there were no differences in terms of mortality (2/562 [0.4%] in the spinal group v 2/514 [0.4%] in the control arm [risk difference (RD) = 0.00 [-0.02, +0.02], p = 1.0), perioperative myocardial infarction (9/421 [2.1%] in the spinal group v 11/407 [2.7%] in the control arm [RD = 0.00, -(0.03, +0.02), p = 0.77), and the length of hospital stay (WMD = -0.28 days [-0.68, -0.13], p = 0.18, with 419 included patients).

CONCLUSIONS

This analysis indicated that spinal analgesia does not improve clinically relevant outcomes in patients undergoing cardiac surgery, discouraging further randomized controlled trials on this topic even if changes in techniques, devices, and drugs could modify the outlook of the comparison between spinal and standard anesthesia in this setting.

[Leipzig fast-track protocol for cardio-anesthesia. Effective, safe and economical]

BACKGROUND

In November 2005 a complex, multimodal anesthesia fast-track protocol (FTP) was introduced for elective cardiac surgery patients in the Cardiac Center of the University of Leipzig which included changing from an opioid regime to remifentanil and postoperative treatment in a special post-anesthesia recovery and care unit. The goal was to speed up recovery times while maintaining safety and improving costs.

METHOD

A total of 421 patients who underwent the FTP and were treated in the special recovery room were analyzed retrospectively. These patients were compared with patients who had been treated by a standard protocol (SP) prior to instituting the FTP. Primary outcomes were time to extubation, length of stay in the intensive care unit (ICU) and treatment costs.

RESULTS

The times to extubation were significantly shorter in the FTP group with 75 min (range 45-110 min) compared to 900 min (range 600-1140 min) in the SP group. Intensive care unit stay and hospital length of stay were also significantly shorter in the FTP group (p<0.01). The reduction of treatment costs of intensive care for FTP patients was 53.5% corresponding to savings of EUR 738 per patient in the FTP group compared with the SP group.

CONCLUSIONS

The Leipzig fast-track protocol for cardio-anesthesia including the central elements of switching opiate therapy to remifentanil and switching patient recovery to a special post-anesthesia recovery and care unit, shortened therapy times, is safe and economically effective.

Predicting Outcomes for Cardiac Surgery Patients After Intensive Care Unit Admission

Most performance assessments of cardiac surgery programs use models based on preoperative risk factors. Models that were primarily developed to assess performance in general intensive care unit (ICU) populations have also been used to evaluate the quality of surgical, anesthetic, and ICU management after cardiac surgery. Although there are currently 5 models for evaluating general ICU populations, only the Acute Physiology and Chronic Health Evaluation (APACHE) system has been independently validated for cardiac surgery patients. This review describes the evolution, rationale, and accuracy of APACHE models that are specific for cardiac surgery patients as well as for patients who have had vascular and thoracic procedures. In addition to performance comparisons based on observed and predicted mortality, APACHE provides similar comparisons of ICU and hospital lengths of stay and duration of mechanical ventilation. However, the low mortality incidence of many cardiac outcomes means that very large numbers of patients must be obtained to get good predictive models. Thus, the equations are not designed for predicting individual patients' outcome but have proven useful in performance comparisons and for quality improvement initiatives.

Analgesia best practice after cardiac surgery

Sources of pain after cardiac surgery include sternotomy, rib retraction, conduit harvest, and drain tubes sites. An analgesic regimen should consider individual patient characteristics, including age, preoperative history of pain and response to analgesics, comorbidities, and psychologic state. Intraoperative and postoperatively administered opioids remain the mainstay of therapy, but adjunctive analgesics such as paracetamol, nonsteroidal anti-inflammatory drugs and tramadol, and regional techniques, can reduce opioid consumption and opioid-induced respiratory depression. This may facilitate earlier tracheal extubation, mobilization, and recovery.

Postoperative effects of low-dose intrathecal morphine in coronary artery bypass surgery

BACKGROUND

Intrathecal morphine has been used in hopes of providing long-lasting postoperative analgesia in patients after cardiac surgery. The aim of this study was to evaluate the effects of 7 micro/kg intrathecal morphine administration in coronary bypass surgery in the postoperative period.

METHODS

We conducted a prospective, randomized, blinded, and controlled study. Twenty-three patients, who underwent primary elective coronary bypass surgery, were randomly allocated to receive morphine 7 micro/kg intrathecally, before the induction of general anesthesia (Group M, n = 12) or no intrathecal injection (Group C, n = 11). Pain scores, determined by visual analogue scale (VAS), were recorded immediately after extubation upon admission to the intensive care unit (ICU), at the 2nd, 4th, 6th, and 18th hour after extubation. Pethidine was administered if the patient's VAS > or = 4 and consumption was recorded. Extubation time and ICU length of stay were also recorded.

RESULTS

VAS scores were lower in the Group M at each measured time than the control group (p = 0.016, 0.023, 0.004, 0.0001, and 0.001, respectively). According to the VAS scores, pethidine requirement was lower in the Group M than the control (p = 0.001). Extubation time (3.58 +/- 1.57 vs. 4.86 +/- 1.38 hours, p = 0.045) and ICU length of stay (16.25 +/- 2.70 vs. 19.30 +/- 2.45 hours, p = 0.014) were also significantly shorter in the Group M than the control group. No significant complications were seen in this group of patients.

CONCLUSIONS

Intrathecal morphine provided effective analgesia, earlier tracheal extubation and less ICU length stay after on-pump coronary bypass surgery. The influence on ICU length of stay requires further evaluations.

Early oral analgesia after fast-track cardiac anesthesia

PURPOSE

Oral analgesia after "fast-track" cardiac anesthesia has not been explored. The aim of this study was to compare two oral oxycodone analgesic regimens.

METHODS

One hundred-twenty patients scheduled for coronary artery bypass grafting were randomly assigned postoperatively to receive immediate-release oxycodone 5 mg and acetaminophen 325 mg (Percocet-5) (group I) per os four times daily, or controlled-release oxycodone 10 mg (OxyContin) (group II) per os every 12 hr and placebo twice daily. Acetaminophen 500 mg per os was used as first-line rescue medication, and immediate-release oxycodone (syrup form) 5 mg per os as second-line rescue medication. Pain intensity was assessed with a visual analogue scale on the first postoperative day, the morning after extubation, and thereafter four times daily for four days. Use of rescue medication and adverse events were recorded.

RESULTS

Baseline demographic and operation-related characteristics were similar in both groups. While pain control was good in both groups, the immediate-release group experienced less pain on all postoperative days (P = 0.003), required significantly less rescue medication, and had fewer adverse effects such as somnolence and nausea.

CONCLUSION

Peroral oxycodone is effective for early pain control after fast-track cardiac anesthesia. Immediate-release oxycodone/ acetaminophen appears to provide better analgesia and fewer side effects compared to controlled-release oxycodone.

Mechanical Ventilation for Cardiac Support

Postoperative lung injury is a common, although decreasing, complication of cardiac surgery. This article discusses various means to prevent and minimize postoperative lung injury. These include lung-protective strategies, pharmacologic strategies, and mechanical ventilation.

The use of pre-operative intrathecal morphine for analgesia following coronary artery bypass surgery

With the emergence of rapid extubation protocols following cardiac surgery, providing adequate analgesia in the early postoperative period is important. This prospective randomised double-blind study investigated the benefits of pre-operative intrathecal administration of low dose morphine in patients undergoing coronary artery bypass graft surgery. Postoperative analgesia, pulmonary function, stress response and postoperative recovery profile were assessed. Thirty patients were allocated into two groups, receiving either 500 mug of morphine intrathecally prior to anaesthesia and intravenous patient-controlled analgesia with morphine postoperatively following tracheal extubation, or only postoperative intravenous patient-controlled analgesia. In the intrathecal group, the total consumption of intravenous morphine following surgery was significantly reduced by 40% and patients reported lower pain scores at rest, during the first 24 h following extubation. Peak expiratory flow rate was greater and postoperative catecholamine release was significantly lower. Patients in the control group had a higher incidence of reduced respiratory rate following extubation.

New approaches and old controversies to postoperative pain control following cardiac surgery

OBJECTIVE

To evaluate the effect of postoperative pain control in cardiac surgical patients on morbidity, mortality and other outcome measures.

BACKGROUND

New approaches in pain control have been introduced over the past decade. The impact of these interventions, either alone or in combination, on perioperative outcome was evaluated in cardiac surgical patients.

METHODS

We searched Medline for the period of 1980 to the present using the key terms analgesics, opioid, non-steroidal anti-inflammatory drugs, cardiac surgery, regional analgesia, spinal, epidural, fast-track cardiac anaesthesia, fast-track cardiac surgery, myocardial ischaemia, myocardial infarction, postoperative care, accelerated care programmes, postoperative complications, and we examined and discussed the articles that were identified to be included in this review.

RESULTS

Pain management in cardiac surgery is becoming more important with the establishment of minimally invasive direct coronary artery bypass surgery and fast-track management of conventional cardiac surgery patients. Advances have been made in this area and encompass specific techniques, such as central neuraxial blockade or selective nerve blocks, and drugs (opioids, sedative-hypnotics and non-steroidal anti-inflammatory drugs). Ideally, these therapies provide not only patient comfort but also mitigate untoward cardiovascular responses, pulmonary responses, and other inflammatory and secondary sympathetic responses. The introduction of these newer approaches to perioperative care has reduced morbidity, but not mortality, in cardiac surgical patients.

CONCLUSIONS

Understanding perioperative pathophysiology and implementation of care regimes to reduce the stress of cardiac surgery, will continue to accelerate rehabilitation associated with decreased hospitalization and increased satisfaction and safety after discharge. Reorganization of the perioperative team (anaesthesiologists, surgeons, nurses and physical therapists) will be essential to achieve successful fast-track cardiac surgical programmes. Developments and improvements of multimodal interventions within the context of 'fast-track' cardiac surgery programmes represents the major challenge for the medical professionals working to achieve a 'pain and risk free' perioperative course.

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

OBJECTIVE

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

DESIGN

Meta-regression.

PATIENTS

Low-risk coronary artery bypass grafting patients.

INTERVENTIONS

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

MEASUREMENTS

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

MAIN RESULTS

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

CONCLUSIONS

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

Intrathecal morphine: effects on perioperative hemodynamics, postoperative analgesia, and stress response for total abdominal hysterectomy

Intrathecal opioids provide postoperative analgesia and hemodynamic stability by depressing the neuroendocrine response during the perioperative period. The effects of preoperative intrathecal morphine on perioperative hemodynamics, stress response, and postoperative analgesia were evaluated in patients undergoing abdominal hysterectomy with general anesthesia. A total of 24 patients were randomly assigned to the morphine group (n=12) or the control group (n=12). Patients in the morphine group were given intrathecal 5 microg/kg(-1) morphine before surgery. In all patients, general anesthesia was induced with 1 g/kg(-1) remifentanil, 2 mg/kg(-1) propofol, and 0.1 mg/kg(-1) vecuronium and was maintained with 1% to 2% sevoflurane-35% oxygen in N2O and remifentanil infusion. All patients received intravenous morphine patient-controlled analgesia after surgery. Postoperative pain was evaluated by means of a visual analogue scale. Blood samples were taken at 4 time points before and up to 4 hours after the start of surgery for assessment of plasma epinephrine, norepinephrine, and glucose. Mean arterial pressure (MAP), heart rate (HR), and adverse effects were recorded. Intraoperative hemodynamics was similar in both groups, but postoperative HR and MAP values at 4 h, 8 h, 12 h, and 20 h were significantly lower in the morphine group (P<.05). Postoperative VAS scores, total morphine consumption, and plasma epinephrine, norepinephrine, and glucose levels were significantly lower in the morphine group than in the control group (P<.05). Preoperative intrathecal morphine enhanced the quality of postoperative analgesia, decreased morphine consumption, and depressed the systemic stress response in patients undergoing total abdominal hysterectomy with general anesthesia.

Low-dose intrathecal morphine does not delay early extubation after cardiac surgery

PURPOSE

This study was designed to examine the efficacy of low-dose intrathecal morphine (ITM) on extubation times and pain control after cardiac surgery.

METHODS

43 patients undergoing elective cardiac surgery were enrolled in this prospective, randomized, double-blind placebo controlled trial. Patients were given a pre-induction dose of ITM (6 microg x kg(-1) per ideal body weight in 5 mL normal saline, group ITM) or 5 mL of intrathecal normal saline (group ITS). Anesthesia was induced with thiopental (3 mg x kg(-1)), sufentanil, midazolam and rocuronium. The total allowable doses of sufentanil and midazolam for the entire case were limited to 0.5 microg x kg(-1) and 0.045 mg x kg(-1) respectively. Anesthesia was maintained with isoflurane before and during cardiopulmonary bypass (CPB), and with propofol after CPB. In the postanesthesia care unit, patients received nurse-administered morphine followed by patient-controlled analgesia morphine. Serial visual analogue scale pain scores, morphine use, mini-mental state examinations and pulmonary function tests were measured for 48 hr. Patient satisfaction questionnaires were completed at the time of discharge.

RESULTS

Mean times to extubation from the application of dressings were short and did not differ between groups (ITM = 41.4 +/- 33.0 min, ITS = 39.2 +/- 37.1 min). During the first 24 hr postoperatively, the ITM group had improved pain control and a lower iv morphine requirement than the control group, both at rest and during deep breathing. Both forced expiratory volume in one second and forced vital capacity were improved in the ITM group. There were no differences in spinal-related side effects or in the overall complication rates. Patient satisfaction was high in both groups.

CONCLUSION

Low-dose ITM for cardiac surgery did not delay early extubation, but it improved postoperative analgesia and pulmonary function.

Intrathecal and Epidural Anesthesia and Analgesia for Cardiac Surgery

Adequate postoperative analgesia prevents unnecessary patient discomfort. It may also decrease morbidity, postoperative hospital length of stay and, thus, cost. Achieving optimal pain relief after cardiac surgery is often difficult. Many techniques are available, and all have specific advantages and disadvantages. Intrathecal and epidural techniques clearly produce reliable analgesia in patients undergoing cardiac surgery. Additional potential benefits include stress response attenuation and thoracic cardiac sympathectomy. The quality of analgesia obtained with thoracic epidural anesthetic techniques is sufficient to allow cardiac surgery to be performed in awake patients without general endotracheal anesthesia. However, applying regional anesthetic techniques to patients undergoing cardiac surgery is not without risk. Side effects of local anesthetics (hypotension) and opioids (pruritus, nausea/vomiting, urinary retention, and respiratory depression), when used in this manner, may complicate perioperative management. Increased risk of hematoma formation in this scenario has generated much of lively debate regarding the acceptable risk-benefit ratio of applying regional anesthetic techniques to patients undergoing cardiac surgery.

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.

Remifentanil use in children undergoing congenital heart surgery for left-to-right shunt lesions

OBJECTIVE

The authors compared the effects of remifentanil with fentanyl on the hemodynamic and respiratory variables in children with left-to-right shunting and pulmonary hypertension.

DESIGN

A prospective, randomized, and controlled design.

SETTING

University hospital.

PARTICIPANTS

Children aged between 3 months and 6 years undergoing pediatric cardiac surgery for correction of left-to-right intracardiac shunting.

INTERVENTIONS

Children were assigned to 1 of the 2 opioids for intraoperative use. Fentanyl was given as a 20 microg/kg intravenous bolus followed by infusion at a rate of 20 microg/kg/h in group 1 (control, n=15), and remifentanil was given as a 2 microg/kg intravenous bolus followed by infusion at a rate of 2 microg/kg/min in group 2 (n=18).

MEASUREMENTS AND MAIN RESULTS

Mean arterial pressures at 30 to 40 minutes postbypass and the first 2 hours postsurgery were higher in the remifentanil group (p<0.05). Heart rates, pulmonary artery pressures, and airway pressures did not differ at any time between groups. Peripheral oxygen saturation values were lower at 30 and 45 minutes in the prebypass period and higher at 1 to 4 hours in the intensive care unit in the remifentanil group (p<0.05). After protamine administration, transient peripheral oxygen desaturation was observed with 10 children in the remifentanil group and with 3 children in the fentanyl group without any hemodynamic deterioration (p=0.029).

CONCLUSION

There were no clinically important differences in hemodynamic and respiratory measurements intraoperatively and during the initial 24 hours postoperatively between fentanyl and remifentanil in pediatric patients undergoing surgical repair of defects with left-to-right shunts.

Regional analgesia in the critically ill

OBJECTIVE

The objective of this review is to analyze and describe the use of regional analgesia in the critically ill.

DATA SOURCE

A Medline search from 1966 to 2004 using the search terms critically ill, nerve blocks, regional analgesia, and regional anesthesia, as well as a search in the Cochrane library, was performed, and standard international textbooks related to critical care and regional anesthesia were searched for practice recommendations.

STUDY SELECTION

Studies, case reports, and review articles relevant to the topic were included.

DATA EXTRACTION AND SYNTHESIS

Data were extracted and analyzed in a descriptive fashion.

CONCLUSION

Regional analgesia using single-injection regional blocks and continuous neuraxial and peripheral catheters can play a valuable role in a multimodal approach to pain management in the critically ill patient to achieve optimum patient comfort and to reduce physiologic and psychological stress. By avoiding high systemic doses of opioids, several complications like withdrawal syndrome, delirium, mental status changes, and gastrointestinal dysfunction can be reduced or minimized. Because of limited patient cooperation during placement and monitoring of continuous regional analgesia, indications for their use must be carefully chosen based on anatomy, clinical features of pain, coagulation status, and logistic circumstances. High-quality nursing care and well-trained physicians are essential prerequisites to use these techniques safely in the critical care environment.

Low dose intrathecal morphine facilitates early extubation after cardiac surgery: results of a retrospective continuous quality improvement audit

PURPOSE

To document one centre's experience with a multimodal analgesic approach, with or without low dose intrathecal morphine (ITM), in facilitating "fast-track" recovery in patients undergoing cardiac surgery.

METHODS

Records of 131 consecutive patients who underwent first time elective cardiac surgery during a four-month period in 2000 were reviewed. Patients were divided into two groups: those receiving and those not receiving preoperative low dose ITM (< 5 microgxkg(-1)) as part of a multimodal analgesic technique. Demographic and surgical characteristics, postoperative morphine use, time to extubation and requirement for antiemetics were recorded.

RESULTS

Overall, 75% of patients were extubated within two hours, and 93% within six hours. Fifty-five patients received, and 76 did not receive, ITM (mean +/- SD 259 +/- 53 microg) along with a multimodal analgesic technique (parasternal infiltration, acetaminophen and indomethacin, and postoperative i.v. morphine). Anesthetic technique involved modest dose opioids, volatile agent and propofol infusion. The groups were similar with respect to preoperative, intraoperative and anesthetic characteristics. Mean extubation time for fast-track patients receiving vs not receiving ITM was 75 +/- 65 vs 117 +/- 85 min (P = 0.003). Intravenous morphine use for the first 12 hr after surgery was also reduced in the ITM group (4.6 +/- 4.1 vs 10.0 +/- 14.8 mg, P = 0.009). There was no difference in rescue antiemetic or antipruritic requirements, failed fast-tracking, or serious adverse events.

CONCLUSIONS

Multimodal postoperative analgesia allowed for uneventful early extubation and low opioid requirements. Low dose ITM further facilitated early extubation, and reduced postoperative analgesic requirements.

Postoperative Analgesia After Spinal Blockade in Infants and Children Undergoing Cardiac Surgery

The aim of this prospective, randomized, controlled clinical trial was to define the opioid analgesic requirement after a remifentanil (REMI)-based anesthetic with spinal anesthetic blockade (SAB+REMI) or without (REMI) spinal blockade for open-heart surgery in children. We enrolled 45 patients who were candidates for tracheal extubation in the operating room after cardiac surgery. Exclusion criteria included age <3 mo and >6 yr, pulmonary hypertension, congestive heart failure, contraindication to SAB, and failure to obtain informed consent. All patients had an inhaled induction with sevoflurane and maintenance of anesthesia with REMI and isoflurane (0.3% end-tidal). In addition, patients assigned to the SAB+REMI group received SAB with tetracaine (0.5-2.0 mg/kg) and morphine (7 mug/kg). After tracheal extubation in the operating room, patients received fentanyl 0.3 mug/kg IV every 10 min by patient-controlled analgesia for pain score = 4. Pain scores and fentanyl doses were recorded every hour for 24 h or until the patient was ready for discharge from the intensive care unit. Patients in the SAB+REMI group had significantly lower pain scores (P = 0.046 for the first 8 h; P =0.05 for 24 h) and received less IV fentanyl (P = 0.003 for the first 8 h; P = 0.004 for 24 h) than those in the REMI group. There were no intergroup differences in adverse effects, including hypotension, bradycardia, highest PaCO(2), lowest pH, episodes of oxygen desaturation, pruritus, and vomiting.

Fast-track coronary artery bypass grafting surgery under general anesthesia with remifentanil and spinal analgesia with morphine and clonidine

OBJECTIVE

Effective postoperative analgesia is a critical part of fast-track cardiac surgery. This study compared the postoperative analgesic effect of fast-track anesthesia with remifentanil and spinal morphine and clonidine with that of sufentanil anesthesia followed by patient-controlled administration of intravenous morphine.

DESIGN

Prospective, blinded, randomized study.

SETTING

Single private institution.

PARTICIPANTS

Forty patients selected for coronary artery bypass graft surgery allocated randomly into 2 groups.

INTERVENTIONS

General anesthesia was performed with etomidate, isoflurane, cisatracurium, and either remifentanil (0.10-0.25 microg/kg/min) or sufentanil (up to 3.5 microg/kg). In the remifentanil group, patients received spinal morphine (4 microg/kg) and clonidine (1 microg/kg) before induction. Postoperatively, patients in both groups were connected to an intravenous patient-controlled analgesia (PCA) morphine pump that delivered a 1-g bolus with a 7-minute lockout interval.

MEASUREMENTS AND MAIN RESULTS

Patients were evaluated for pain on a visual analog scale (VAS), at rest and on deep breathing, and for intravenous PCA morphine consumption during 24 hours. The intravenous PCA morphine 24-hour cumulative dose was lower in the fast-track than in the control group (15.8+/-12.6 v 32.7+/-22.3 mg, p<0.05). Before extubation, VAS scores were higher in the fast-track group, but after they were lower both at rest and during deep breathing. Extubation delay was shorter in the fast-track group (156.5+/-46.1 v 272+/-116.4 minutes, p<0.05).

CONCLUSION

The combination of anesthesia with remifentanil and spinal analgesia with morphine and clonidine produces effective analgesia after coronary artery surgery and a rapid extubation time.

Recent advances in intravenous anaesthesia

Efforts to develop new hypnotic compounds continue, although several have recently failed in development. Propofol has been reformulated in various presentations with and without preservatives. Pharmacokinetic and pharmacodynamic differences exist between some of these preparations, and it is currently unclear whether any have substantial advantages over the original presentation. The use of target-controlled infusion (TCI) has been extended to include paediatric anaesthesia and sedation. Application of TCI to remifentanil is now licensed. Linking of electroencephalogram (EEG) monitoring to TCI for closed-loop anaesthesia remains a research tool, although commercial development may follow. The availability of stereoisomer ketamine and improved understanding of its pharmacology have increased non-anaesthetic use of ketamine as an adjunct analgesic. It may be useful in subhypnotic doses for postsurgical patients with pain refractory to morphine administration.

Comparative tolerability of sedative agents in head-injured adults

Sedative agents are widely used in the management of patients with head injury. These drugs can facilitate assisted ventilation and may provide useful reductions in cerebral oxygen demand. However, they may compromise cerebral oxygen delivery via their cardiovascular effects. In addition, individual sedative agents have specific and sometimes serious adverse effects. This review focuses on the different classes of sedative agents used in head injury, with a discussion of their role in the context of clinical pathophysiology. While there is no sedative that has all the desirable characteristics for an agent in this clinical setting, careful titration of dose, combination of agents, and a clear understanding of the pathophysiology and pharmacology of these agents will allow safe sedative administration in head injury.

Remifentanil: an update

PURPOSE OF REVIEW

Remifentanil has now reached maturity, as reflected by the increasing number of clinical papers relating to its use. Its position among anaesthetic drugs is now better understood, and this review will attempt to place it in the context of current clinical practice.

RECENT FINDINGS AND SUMMARY

Propofol reduces the initial distribution of remifentanil, leading to higher concentrations during induction. Propofol and remifentanil administered together at sedative doses display a major synergistic interaction on the respiratory drive. Remifentanil accelerates the penetration of sevoflurane to its site of effect. The risk of intraoperative awareness seems to be low when remifentanil is associated to very low concentrations of hypnotic drugs, but this field warrants further investigation. Acute tolerance to opioids and its prevention remain controversial.

SUMMARY

Remifentanil is the opioid of choice for tracheal intubation without muscle relaxants. It provides an alternative to regional anaesthesia in labour pain control. Target-controlled infusion may further improve the administration of remifentanil.