Stress induced IL-10 does not seem to be essential for early monocyte deactivation following cardiac surgery

Thoracic Epidural Anesthesia in Cardiac Surgery: A Systematic Review, Meta-Analysis, and Trial Sequential Analysis of Randomized Controlled Trials

BACKGROUND

Research on fast-track recovery protocols postulates that thoracic epidural anesthesia (TEA) in cardiac surgery contributes to improved postoperative outcomes. However, concerns about TEA's safety hinder its widespread usage. We conducted a systematic review and meta-analysis to assess the benefits and risks of TEA in cardiac surgery.

METHODS

We searched 4 databases for randomized controlled trials (RCTs) assessing the use of TEA against only general anesthesia (GA) in adults undergoing cardiac surgery, up till June 4, 2022. We conducted random-effects meta-analyses, evaluated risk of bias using the Cochrane Risk-of-Bias 2 tool, and rated certainty of evidence via the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach. Primary outcomes were intensive care unit (ICU), hospital length of stay, extubation time (ET), and mortality. Other outcomes included postoperative complications. Trial sequential analysis (TSA) was conducted on all outcomes to elicit statistical and clinical benefit.

RESULTS

Our meta-analysis included 51 RCTs (2112 TEA patients and 2220 GA patients). TEA significantly reduced ICU length of stay (-6.9 hours; 95% confidence interval [CI], -12.5 to -1.2; P = .018), hospital length of stay (-0.8 days; 95% CI, -1.1 to -0.4; P < .0001), and ET (-2.9 hours; 95% CI, -3.7 to -2.0; P < .0001). However, we found no significant change in mortality. TSA found that the cumulative Z-curve passed the TSA-adjusted boundary for ICU length of stay, hospital length of stay, and ET, suggesting a clinical benefit. TEA also significantly reduced pain scores, pooled pulmonary complications, transfusion requirements, delirium, and arrhythmia, without additional complications such as epidural hematomas, of which the risk was estimated to be <0.14%.

CONCLUSIONS

TEA reduces ICU and hospital length of stay, and postoperative complications in patients undergoing cardiac surgery with minimal reported complications such as epidural hematomas. These findings favor the use of TEA in cardiac surgery and warrant consideration for use in cardiac surgeries worldwide.

Comparison of regional anesthetic techniques for postoperative analgesia after adult cardiac surgery: bayesian network meta-analysis

Background

Patients usually suffer acute pain after cardiac surgery. Numerous regional anesthetic techniques have been used for those patients under general anesthesia. The most effective regional anesthetic technique was still unclear.

Methods

Five databases were searched, including PubMed, MEDLINE, Embase, ClinicalTrials.gov, and Cochrane Library. The efficiency outcomes were pain scores, cumulative morphine consumption, and the need for rescue analgesia in this Bayesian analysis. Postoperative nausea, vomiting and pruritus were safety outcomes. Functional outcomes included the time to tracheal extubation, ICU stay, hospital stay, and mortality.

Results

This meta-analysis included 65 randomized controlled trials involving 5,013 patients. Eight regional anesthetic techniques were involved, including thoracic epidural analgesia (TEA), erector spinae plane block, and transversus thoracic muscle plane block. Compared to controls (who have not received regional anesthetic techniques), TEA reduced the pain scores at 6, 12, 24 and 48 h both at rest and cough, decreased the rate of need for rescue analgesia (OR = 0.10, 95% CI: 0.016-0.55), shortened the time to tracheal extubation (MD = -181.55, 95% CI: -243.05 to -121.33) and the duration of hospital stay (MD = -0.73, 95% CI: -1.22 to -0.24). Erector spinae plane block reduced the pain score 6 h at rest and the risk of pruritus, shortened the duration of ICU stay compared to controls. Transversus thoracic muscle plane block reduced the pain scores 6 and 12 h at rest compared to controls. The cumulative morphine consumption of each technique was similar at 24, 48 h. Other outcomes were also similar among these regional anesthetic techniques.

Conclusions

TEA seems the most effective regional postoperative anesthesia for patients after cardiac surgery by reducing the pain scores and decreasing the rate of need for rescue analgesia.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, ID: CRD42021276645.

Epidural analgesia for adults undergoing cardiac surgery with or without cardiopulmonary bypass

BACKGROUND

General anaesthesia combined with epidural analgesia may have a beneficial effect on clinical outcomes. However, use of epidural analgesia for cardiac surgery is controversial due to a theoretical increased risk of epidural haematoma associated with systemic heparinization. This review was published in 2013, and it was updated in 2019.

OBJECTIVES

To determine the impact of perioperative epidural analgesia in adults undergoing cardiac surgery, with or without cardiopulmonary bypass, on perioperative mortality and cardiac, pulmonary, or neurological morbidity.

SEARCH METHODS

We searched CENTRAL, MEDLINE, and Embase in November 2018, and two trial registers up to February 2019, together with references and relevant conference abstracts.

SELECTION CRITERIA

We included all randomized controlled trials (RCTs) including adults undergoing any type of cardiac surgery under general anaesthesia and comparing epidural analgesia versus another modality of postoperative pain treatment. The primary outcome was mortality.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as expected by Cochrane.

MAIN RESULTS

We included 69 trials with 4860 participants: 2404 given epidural analgesia and 2456 receiving comparators (systemic analgesia, peripheral nerve block, intrapleural analgesia, or wound infiltration). The mean (or median) age of participants varied between 43.5 years and 74.6 years. Surgeries performed were coronary artery bypass grafting or valvular procedures and surgeries for congenital heart disease. We judged that no trials were at low risk of bias for all domains, and that all trials were at unclear/high risk of bias for blinding of participants and personnel taking care of study participants.Epidural analgesia versus systemic analgesiaTrials show there may be no difference in mortality at 0 to 30 days (risk difference (RD) 0.00, 95% confidence interval (CI) -0.01 to 0.01; 38 trials with 3418 participants; low-quality evidence), and there may be a reduction in myocardial infarction at 0 to 30 days (RD -0.01, 95% CI -0.02 to 0.00; 26 trials with 2713 participants; low-quality evidence). Epidural analgesia may reduce the risk of 0 to 30 days respiratory depression (RD -0.03, 95% CI -0.05 to -0.01; 21 trials with 1736 participants; low-quality evidence). There is probably little or no difference in risk of pneumonia at 0 to 30 days (RD -0.03, 95% CI -0.07 to 0.01; 10 trials with 1107 participants; moderate-quality evidence), and epidural analgesia probably reduces the risk of atrial fibrillation or atrial flutter at 0 to 2 weeks (RD -0.06, 95% CI -0.10 to -0.01; 18 trials with 2431 participants; moderate-quality evidence). There may be no difference in cerebrovascular accidents at 0 to 30 days (RD -0.00, 95% CI -0.01 to 0.01; 18 trials with 2232 participants; very low-quality evidence), and none of the included trials reported any epidural haematoma events at 0 to 30 days (53 trials with 3982 participants; low-quality evidence). Epidural analgesia probably reduces the duration of tracheal intubation by the equivalent of 2.4 hours (standardized mean difference (SMD) -0.78, 95% CI -1.01 to -0.55; 40 trials with 3353 participants; moderate-quality evidence). Epidural analgesia reduces pain at rest and on movement up to 72 hours after surgery. At six to eight hours, researchers noted a reduction in pain, equivalent to a reduction of 1 point on a 0 to 10 pain scale (SMD -1.35, 95% CI -1.98 to -0.72; 10 trials with 502 participants; moderate-quality evidence). Epidural analgesia may increase risk of hypotension (RD 0.21, 95% CI 0.09 to 0.33; 17 trials with 870 participants; low-quality evidence) but may make little or no difference in the need for infusion of inotropics or vasopressors (RD 0.00, 95% CI -0.06 to 0.07; 23 trials with 1821 participants; low-quality evidence).Epidural analgesia versus other comparatorsFewer studies compared epidural analgesia versus peripheral nerve blocks (four studies), intrapleural analgesia (one study), and wound infiltration (one study). Investigators provided no data for pulmonary complications, atrial fibrillation or flutter, or for any of the comparisons. When reported, other outcomes for these comparisons (mortality, myocardial infarction, neurological complications, duration of tracheal intubation, pain, and haemodynamic support) were uncertain due to the small numbers of trials and participants.

AUTHORS' CONCLUSIONS

Compared with systemic analgesia, epidural analgesia may reduce the risk of myocardial infarction, respiratory depression, and atrial fibrillation/atrial flutter, as well as the duration of tracheal intubation and pain, in adults undergoing cardiac surgery. There may be little or no difference in mortality, pneumonia, and epidural haematoma, and effects on cerebrovascular accident are uncertain. Evidence is insufficient to show the effects of epidural analgesia compared with peripheral nerve blocks, intrapleural analgesia, or wound infiltration.

Smoking, Gender, and Overweight Are Important Influencing Factors on Monocytic HLA-DR before and after Major Cancer Surgery

Background

Monocytic human leukocyte antigen D related (mHLA-DR) is essential for antigen-presentation. Downregulation of mHLA-DR emerged as a general biomarker of impaired immunity seen in patients with sepsis and pneumonia and after major surgery. Influencing factors of mHLA-DR such as age, overweight, diabetes, smoking, and gender remain unclear.

Methods

We analyzed 20 patients after esophageal or pancreatic resection of a prospective, randomized, placebo-controlled, double-blind trial (placebo group). mHLA-DR was determined from day of surgery (od) until postoperative day (pod) 5. Statistical analyses were performed using multivariate generalized estimating equation analyses (GEE), nonparametric multivariate analysis of longitudinal data, and univariate post hoc nonparametric Mann–Whitney tests.

Results

In GEE, smoking and gender were confirmed as significant influencing factors over time. Univariate analyses of mHLA-DR between smokers and nonsmokers showed lower preoperative levels (p = 0.010) and a trend towards lower levels on pod5 (p = 0.056) in smokers. Lower mHLA-DR was seen in men on pod3 (p = 0.038) and on pod5 (p = 0.026). Overweight patients (BMI > 25 kg/m²) had lower levels of mHLA-DR on pod3 (p = 0.039) and pod4 (p = 0.047).

Conclusion

Smoking is an important influencing factor on pre- and postoperative immune function while postoperative immune function was influenced by gender and overweight. Clinical trial registered with ISRCTN27114642.

Surgical and not analgesic technique affects postoperative inflammation following colorectal cancer surgery: a prospective, randomized study

AIM

Epidural analgesia reduces the surgical stress response. However, its effect on pro- and anti-inflammatory cytokines in the genesis of inflammation following major abdominal surgery remains unclear. Our main objective was to elucidate whether perioperative epidural analgesia prevents the inflammatory response following colorectal cancer surgery.

METHODS

Ninety-six patients scheduled for open or laparoscopic surgery were randomized to epidural analgesia (group E) or patient-controlled intravenous analgesia (group P). Surgery and anaesthesia were standardized in both groups. Plasma cortisol, insulin and serum cytokines [interleukin 1β (IL-1β), IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70, IL-13, tumour necrosis factor α, interferon γ, granulocyte-macrophage colony-stimulating factor, prostaglandin E₂ and vascular endothelial growth factor] were measured preoperatively (T0), 1-6 h postoperatively (T1) and 3-5 days postoperatively (T2). Mixed model analysis was used, after logarithmic transformation when appropriate, for analyses of cytokines and stress markers.

RESULTS

>There were no significant differences in any serum cytokine concentration between groups P and E at any time point except for IL-10 which was 87% higher in group P [median and range 4.1 (2.3-9.2) pg/ml] compared to group E [2.6 (1.3-4.7) pg/ml] (P = 0.002) at T1. There was no difference in plasma cortisol and insulin between the groups at any time point after surgery. A significant difference in median serum cytokine concentration was found between open and laparoscopic surgery with higher levels of IL-6, IL-8 and IL-10 at T1 in patients undergoing open surgery compared to laparoscopic surgery. No difference in serum cytokine concentration was detected between the groups or between the surgical technique at T2.

CONCLUSIONS

Open surgery, compared to laparoscopic surgery, has greater impact on these inflammatory mediators than epidural analgesia vs intravenous analgesia.

Impact of epidural analgesia on mortality and morbidity after surgery: systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

To quantify benefit and harm of epidural analgesia, compared with systemic opioid analgesia, in adults having surgery under general anesthesia.

BACKGROUND

It remains controversial whether adding epidural analgesia to general anesthesia decreases postoperative morbidity and mortality.

METHODS

We searched CENTRAL, EMBASE, PubMed, CINAHL, and BIOSIS till July 2012. We included randomized controlled trials comparing epidural analgesia (with local anesthetics, lasting for ≥ 24 hours postoperatively) with systemic analgesia in adults having surgery under general anesthesia, and reporting on mortality or any morbidity endpoint.

RESULTS

A total of 125 trials (9044 patients, 4525 received epidural analgesia) were eligible. In 10 trials (2201 patients; 87 deaths), reporting on mortality as a primary or secondary endpoint, the risk of death was decreased with epidural analgesia (3.1% vs 4.9%; odds ratio, 0.60; 95% confidence interval, 0.39-0.93). Epidural analgesia significantly decreased the risk of atrial fibrillation, supraventricular tachycardia, deep vein thrombosis, respiratory depression, atelectasis, pneumonia, ileus, and postoperative nausea and vomiting, and also improved recovery of bowel function, but significantly increased the risk of arterial hypotension, pruritus, urinary retention, and motor blockade. Technical failures occurred in 6.1% of patients.

CONCLUSIONS

In adults having surgery under general anesthesia, concomitant epidural analgesia reduces postoperative mortality and improves a multitude of cardiovascular, respiratory, and gastrointestinal morbidity endpoints compared with patients receiving systemic analgesia. Because adverse effects and technical failures cannot be ruled out, individual risk-benefit analyses and professional care are recommended.

Dysfunction of alveolar macrophages after cardiac surgery and postoperative pneumonia?--An observational study

Introduction

Patients undergoing cardiac surgery have an increased risk of postoperative pneumonia. Pulmonary immune dysfunction might be a contributing factor. We therefore determined changes of the surface molecules on alveolar macrophages (AMs). To characterize modulation in patients with pneumonia we correlated these changes to the development of postoperative pneumonia.

Methods

After ethical approval and written informed consent, 33 patients undergoing elective coronary bypass grafting surgery were included in this observational study. Peripheral blood cells and alveolar lavage fluid were collected directly after induction of anesthesia and two hours after separation from cardiopulmonary bypass (CPB). Human leukocyte antigen-DR (HLA-DR) and toll-like receptors (TLR) 2/4 expression on monocytes and AM were assessed by flow cytometry. A total of three patients developed postoperative pneumonia determined according to the criteria of the Center of Disease Control. Statistical analysis was performed with the Mann–Whitney-U test and Wilcoxon test.

Results

We found significant changes of phenotypic and functional immune markers on AMs after cardiac surgery. HLA-DR expression on peripheral blood monocytes and AMs was significantly reduced compared to baseline in all patients (each approximately 30%). After surgery patients who developed postoperative pneumonia revealed a trend of stronger reduction of HLA-DR expression (83.7% versus 27.1%) and TLR4 expression on AMs (46.1% versus 9.9%) compared to patients without pneumonia. Already before surgery, the baseline of TLR2 expression on AM was significantly lower (27.7%) in patients who developed postoperative pneumonia.

Conclusions

As far as we know this is the first study that shows an early impairment of lung cellular immune response after cardiac surgery. These findings can help to understand the role of cell-mediated immunosuppression and its association to the development of postoperative pneumonia.

Effects of continuous epidural anesthesia and postoperative epidural analgesia on pain management and stress response in patients undergoing major spinal surgery

STUDY DESIGN

A prospective, randomized study was used to compare 2 anesthesia/analgesia methods for reconstructive spine surgery.

OBJECTIVE

To assess the efficacy and influence of 2 anesthetic methods on clinical outcome and stress response during reconstructive spine surgery.

SUMMARY OF BACKGROUND DATA

Pain control is an important goal of the postoperative care after spinal surgery. Some prior studies have suggested that epidural anesthesia with or without postoperative epidural analgesia may blunt the surgical stress response after major surgery. This treatment approach has not been fully investigated for patients undergoing major spinal surgery. We hypothesized that the stress response after major spine surgery would be attenuated by continuous epidural anesthesia/analgesia with ropivacaine, fentanyl, and epinephrine.

METHODS

Eighty-five patients were randomly allocated to 2 groups as follows: group E (n = 45) had epidural anesthesia and endotracheal anesthesia with sevoflurane during surgery and continuous epidural analgesia with ropivacaine, fentanyl, and epinephrine after surgery; group G (n = 40) had general anesthesia with sevoflurane and fentanyl and systemically administered opioids after surgery. Patient pain, nausea, mobility, and satisfaction were measured after surgery along with levels of cortisol, glucose, interleukin (IL)-1β, IL-6, and IL-10 during and after surgery.

RESULTS

In group E, there were significantly less pain, less nausea, earlier mobility, and higher satisfaction than those in group G. Group E also experienced significantly less introperative and postoperative blood loss. Group E demonstrated lower levels of glucose, cortisol, IL-1β, IL-6, and IL-10 during the postoperative period.

CONCLUSION

Combined epidural/general anesthesia and postoperative epidural analgesia produced better pain control, less bleeding, and a lower surgical stress response than general anesthesia with postoperative systemically administered narcotic analgesia. This technique deserves further study in the setting of major spinal surgery.

Effects of surgery, general anesthesia, and perioperative epidural analgesia on the immune function of patients with non-small cell lung cancer

STUDY OBJECTIVE

To assess preoperative and postoperative immune function in patients undergoing surgical resection of non-small cell lung cancer during general anesthesia and postoperative epidural analgesia.

DESIGN

Observational single-center study.

SETTING

University-affiliated academic center.

PATIENTS

24 adult, ASA physical status 3 and 4 patients with stage 1, 2, or 3 non-small cell lung cancer. No study patient received preoperative chemotherapy or radiation.

INTERVENTIONS

Patients underwent thoracotomy with general anesthesia and postoperative epidural analgesia.

MEASUREMENTS

Bispectral index monitoring, sevoflurane requirements, and intraoperative transfusions were recorded. Total fentanyl consumption and pain (verbal numeric rating scale) were recorded 24 hours after surgery. Preoperative and 24-hour postoperative natural killer cell percentage and function and percentages of natural killer T cells, T helper cells (CD4+), and cytotoxic T lymphocytes (CD8+) were measured. Plasma concentrations of the TH1 cytokine interleukin-2 and interferon-gamma and the TH2 cytokines interleukin-4 were measured at the same time points.

RESULTS

The percentage (preoperative, 13.07 ± 9.81% vs postoperative, 9.6 ± 6.57%, P < 0.001) and function (preoperative, 31.61 ± 21.96%; postoperative, 13.61 ± 9.36%; P < 0.001) of natural killer cells was significantly decreased after surgery, but the percentage of natural killer T cells, T helper cells (CD4+), and cytotoxic T lymphocytes (CD8+) remained unchanged postoperatively; thus, the CD4/CD8 ratio remained unchanged. Postoperative plasma concentrations of the three cytokines were similar to preoperative levels; therefore, the TH1/TH2 ratio also remained unchanged.

CONCLUSIONS

Innate immunity is depressed in patients with non-small cell lung cancer after surgical resection, and immunity is not preserved by the use of postoperative epidural analgesia.

Thoracic epidural analgesia inhibits the neuro-hormonal but not the acute inflammatory stress response after radical retropubic prostatectomy

BACKGROUND

Epidural anaesthesia and analgesia has been shown to suppress the neuro-hormonal stress response, but its role in the inflammatory response is unclear. The primary aim was to assess whether the choice of analgesic technique influences these processes in patients undergoing radical retropubic prostatectomy.

METHODS

Twenty-six patients were randomized to Group P (systemic opioid-based analgesia) or Group E (thoracic epidural-based analgesia) perioperatively. Induction and maintenance of anaesthesia followed a standardized protocol. The following measurements were made perioperatively: plasma cortisol, glucose, insulin, C-reactive proteins, leucocyte count, plasma cytokines [interleukin (IL)-6, tumour necrosis factor (TNF)-α], and pokeweed mitogen-stimulated cytokines [interferon (IFN)-γ, IL-2, IL-12p70, IL-10, IL-4, and IL-17]. Other parameters recorded were pain, morphine consumption, and perioperative complications.

RESULTS

Plasma concentration of cortisol and glucose were significantly higher in Group P compared with Group E at the end of surgery, the mean difference was 232 nmol litre(-1) [95% confidence interval (CI) 84-381] (P=0.004) and 1.6 mmol litre(-1) (95% CI 0.6-2.5) (P=0.003), respectively. No significant differences were seen in IL-6 and TNF-α at 24 h (P=0.953 and 0.368, respectively) and at 72 h (P=0.931 and 0.691, respectively). IL-17 was higher in Group P compared with Group E, both at 24 h (P=0.001) and 72 h (P=0.018) after operation. Pain intensity was significantly greater in Group P compared with Group E (P<0.05) up to 24 h.

CONCLUSIONS

In this small prospective randomized study, thoracic epidural analgesia reduced the early postoperative stress response but not the acute inflammatory response after radical retrobupic prostatectomy, suggesting that other pathways are involved during the acute phase reaction.

Comparison of the clinical application of reactive oxygen species and inflammatory markers in patients with endocarditis

INTRODUCTION

Infective endocarditis (IE) is still connected with high operative mortality. Inflammatory markers are commonly used in monitoring patient clinical condition. Respiratory burst and reactive oxygen species (ROS) are the main way of pathogen elimination. Specificity of this process in the aspect of bacterial infection is the key for correlation assessment between ROS and inflammatory markers in patients with IE. In the study, assessment of ROS as a clinical indicator in IE was conducted.

MATERIAL AND METHODS

During 2007/2008 in the Cardiosurgical Clinic of the Medical University in Lodz there were 20 patients operated on for IE. The examined population consisted of 13 men and 7 women, aged from 23 to 74 years. Inflammatory markers - leukocytosis (WBC), C-reactive protein (CRP), procalcitonin (PCT) and erythrocyte sedimentation rate (ESR) - were assessed preoperatively, on the 3(rd), 7(th), 12(th) and 21(st) day. Simultaneously, with the second venous blood sample chemiluminescence (luminal enhanced whole blood chemiluminescence) was carried out and used to assess ROS production. The results were analyzed statistically.

RESULTS

Positive correlation between ESR, CRP and ROS in the preoperative period was confirmed. An increase in ROS and a statistically significant increase in inflammatory markers on the 3(rd) day were observed. The ROS normalized on the 12(th) day. Marked individual variability was specific for the inflammatory markers. Despite the significant decrease, not all of them achieved a normal level at the last control point.

CONCLUSIONS

Assessment of ROS seems to be a universal parameter with possible application in patients with IE.

Protective effects of steroids in cardiac surgery: a meta-analysis of randomized double-blind trials

OBJECTIVE

Cardiac surgery and cardiopulmonary bypass (CPB) induce an acute inflammatory response contributing to postoperative morbidity. The use of steroids as anti-inflammatory agents in surgery using CPB has been tested in many trials and has been shown to have good anti-inflammatory effects but no clear clinical advantages for the lack of an adequately powered sample size. The aim of this study was to evaluate the effects of steroid treatment on mortality and morbidity after cardiac surgery.

DESIGN

A systematic meta-analysis of randomized double-blind trials (RDBs).

SETTING

A university hospital.

PARTICIPANTS

Adult patients who underwent cardiac surgery.

MEASUREMENTS AND MAIN RESULTS

A trial search was performed through PubMed and Cochrane databases from 1966 to January 2009. Among 104 clinical trials reviewed, 31 RDB trials (1,974 patients) were considered suitable to be analyzed. A quality assessment of the trials was performed using the Jadad score. The types of steroid used in these trials were methylprednisolone (51.4%), dexamethasone (34.3%), hydrocortisone (5.7%), prednisolone (2.9%), or a combination of methylprednisolone and dexamethasone (5.7%). Steroid prophylaxis provided a protective effect preventing postoperative atrial fibrillation (odds ratio = 0.56; confidence interval [CI] 0.44-0.72, p < 0.0001), reducing postoperative blood loss (mean difference = -204.2 mL; CI from -287.4 to -121 mL; p < 0.0001), and reducing intensive care unit (mean difference = -6.6 hours; CI from -10.5 to -2.7 hours, p = 0.0007) and overall hospital stay (mean difference = -0.8 days; CI from -1.4 to -0.2 days, p = 0.01). Steroid prophylaxis had no effect on postoperative mortality, mechanical ventilation duration, re-exploration for bleeding, and postoperative infection.

CONCLUSIONS

A systematic review of RDB trials reveals that steroid prophylaxis may reduce morbidity after cardiac surgery and does not increase the risk of postoperative infections.

Differential down-regulation of HLA-DR on monocyte subpopulations during systemic inflammation

Introduction

Decreased expression of human leukocyte antigen class II (HLA-DR) on monocytes is a hallmark of altered immune status in patients with a systemic inflammatory response syndrome (SIRS). So far, the analyses were mainly performed without taking into account monocytes subpopulations.

Methods

We studied this modification on CD14^HIGH and CD14^LOW monocytes of 20 SIRS patients undergoing abdominal aortic surgery (AAS), 20 patients undergoing carotid artery surgery (CAS), and 9 healthy controls, and we investigated mediators and intracellular molecules that may be involved in this process.

Results

HLA-DR on CD14^HIGH monocytes started to decrease during surgery, after blood reperfusion, and was further reduced post-surgery. In contrast, HLA-DR expression on CD14^LOW cells only decreased after surgery, and to a lesser extent than on CD14^HIGH monocytes. Negative correlations were found between the reduction of HLA-DR expression and the change in cortisol levels for both subpopulations, whereas a negative correlation between interleukin-10 (IL-10) levels and HLA-DR modulation was only observed for CD14^HIGH cells. In accordance with these ex vivo results, HLA-DR on CD14^HIGH and CD14^LOW monocytes of healthy donors was reduced following incubation with hydrocortisone, whereas IL-10 only acted on CD14^HIGH subpopulation. Furthermore, flow cytometry revealed that the expression of IL-10 receptor was higher on CD14^HIGH versus CD14^LOW monocytes. In addition, hydrocortisone, and to a lesser extent IL-10, reversed the up-regulation of HLA-DR induced by bacterial products. Finally, membrane-associated RING-CH-1 protein (MARCH1) mRNA, a negative regulator of MHC class II, was up-regulated in monocytes of AAS patients on Day 1 post-surgery, and in those of healthy subjects exposed to hydrocortisone.

Conclusions

This study reveals that HLA-DR expression is modulated differently on CD14^HIGH (classical) versus CD14^LOW (inflammatory) monocytes after systemic inflammation.

Differential effects of propofol and isoflurane on the activation of T-helper cells in lung cancer patients

It is suggested that activation and differentiation of T-helper cells are required for peri-operative anti-tumor and anti-infection immunity. The present study aimed to evaluate whether propofol stimulates the activation and differentiation of these cells in patients undergoing pulmonary lobectomy for non-small-cell lung cancer. Thirty patients were randomly allocated to receive propofol or isoflurane throughout surgery. The CD4(+)CD28(+) percentage (p < 0.0001) and the ratio of interferon-gamma:interleukin-4 (p = 0.001) all increased with propofol but showed no change with isoflurane. In contrast, cortisol increased with isoflurane (p < 0.0001) but not with propofol over time (p = 0.06). We conclude that propofol promotes activation and differentiation of peripheral T-helper cells.

The perioperative period is an underutilized window of therapeutic opportunity in patients with colorectal cancer

OBJECTIVE

In this review, we address the underlying mechanisms by which surgery augments metastases outgrowth and how these insights can be used to develop perioperative therapeutic strategies for prevention of tumor recurrence.

SUMMARY BACKGROUND DATA

Surgical removal of the primary tumor provides the best chance of long-term disease-free survival for patients with colorectal cancer (CRC). Unfortunately, a significant part of CRC patients will develop metastases, even after successful resection of the primary tumor. Paradoxically, it is now becoming clear that surgery itself contributes to development of both local recurrences and distant metastases.

METHODS

Data for this review were identified by searches of PubMed and references from relevant articles using the search terms "surgery," "CRC," and "metastases."

RESULTS

Surgical trauma and concomitant wound-healing processes induce local and systemic changes, including impairment of tissue integrity and production of inflammatory mediators and angiogenic factors. This can lead to immune suppression and enhanced growth or adhesion of tumor cells, all of which increase the chance of exfoliated tumor cells developing into secondary malignancies.

CONCLUSIONS

Because surgery remains the appropriate and necessary means of treatment for most CRC patients, new adjuvant therapeutic strategies that prevent tumor recurrence after surgery need to be explored since the perioperative therapeutic window of opportunity offers promising means of improving patient outcome but is unfortunately underutilized.

Psychological stress suppresses innate IFN-gamma production via glucocorticoid receptor activation: reversal by the anxiolytic chlordiazepoxide

Studies in humans and in animals indicate that psychological stress can modulate immune responses. Here we demonstrate that exposure to psychological stress (restraint stress) suppresses innate interferon (IFN)-gamma production in mice following an in vivo lipopolysaccharide (LPS) challenge. IFN-gamma signaling was also impaired by stress, as indicated by reduced STAT1 phosphorylation and reduced expression of the IFN-gamma-inducible genes, inducible nitric oxide synthase (iNOS) and IFN-gamma-inducible protein 10 (IP-10/CXCL10). Furthermore, restraint stress suppressed production of the IFN-gamma inducing cytokine interleukin (IL)-12 and increased production of the anti-inflammatory cytokine IL-10, which can inhibit both IL-12 and IFN-gamma production. However, using IL-10 knockout mice, we demonstrate that IL-10 does not mediate the suppressive effect of restraint stress on innate IFN-gamma production. Restraint stress increased corticosterone concentrations in serum and spleen, and consistent with a role for glucocorticoids in the immunosuppressive actions of stress, pre-treatment with the glucocorticoid receptor antagonist mifepristone completely blocked the stress-related suppression of innate IFN-gamma production. Addition of exogenous IL-12 to LPS-stimulated spleen cells reversed the suppressive effect of both restraint stress and corticosterone on IFN-gamma production. These data suggest that reduced IL-12 production is a key event in stress-induced suppression of innate IFN-gamma production. Finally, we demonstrate that pre-treatment with the anxiolytic drug chlordiazepoxide prevents the suppressive effect of stress on innate IFN-gamma production, and also attenuates the stress-induced increase in circulating corticosterone concentrations.

Expression of Toll-like receptors 2 and 4 on innate immunity cells modulated by cardiac surgical operation

OBJECTIVE

This study aimed to follow-up on the changes in the expression of Toll-like receptors (TLRs) on monocytes and granulocytes in venous blood of patients undergoing cardiac surgical operation.

MATERIAL AND METHODS

TLR2 and TLR4 expression on blood cells was determined by flow cytometry in 40 patients undergoing cardiac surgery performed either with cardiopulmonary bypass (CPB) ("on-pump") or without it ("off-pump").

RESULTS

Intensity of the expression of TLR2 on both monocytes and granulocytes, expressed as median fluorescence intensity, is significantly reduced during CPB, being lower in both groups at the finish of surgery. These changes are not so remarkable in the case of TLR4 expression. Compared to "on-pump" patients, there is a higher relative number of TLR2(+) granulocytes in "off-pump" patients at the finish of surgery and of TLR4(+) granulocytes on the first postoperative day.

CONCLUSIONS

We found characteristic patterns in the expression of TLR2 and TLR4 on monocytes and granulocytes in venous blood of patients undergoing cardiac surgery with or without CPB.

The importance of immune dysfunction in determining outcome in acute liver failure

Acute liver failure (ALF) shares striking similarities with septic shock with regard to the features of systemic inflammation, progression to multiple organ dysfunction and functional immunoparesis. While the existence of opposing systemic pro- and anti-inflammatory profiles resulting in organ failure and immune dysfunction are well recognised in septic shock, characterization of these processes in ALF has only recently been described. This review explores the evolution of the systemic inflammation in acute liver failure, its relation to disease progression, exacerbation of liver injury and development of innate immune dysfunction and extra-hepatic organ failure as sequelae. Defects in innate immunity are described in hepatic and extra-hepatic compartments. Clinical studies measuring levels of pro- and anti-inflammatory cytokines and expression of the antigen presentation molecule HLA-DR on monocytes, in combination with ex-vivo experiments, demonstrate that the persistence of a compensatory anti-inflammatory response syndrome, leading to functional monocyte deactivation, is a central event in the evolution of systemic immune dysfunction. Accurate immune profiling in ALF may permit the development of immunomodulatory strategies in order to improve outcome in this condition.

Dopamine treatment in brain-dead rats mediates anti-inflammatory effects: the role of hemodynamic stabilization and D-receptor stimulation

Brain death (BD) is associated with profound inflammation in end-organs. Dopamine (DA) treatment reduces this inflammatory response, but the underlying mechanisms remain thus far largely unknown. In this study, we investigated if the anti-inflammatory effect of DA was related to hemodynamic stabilization and by which receptors it was mediated. BD was induced in F344 donor rats. DA was given either before BD for 24 h or after BD induction during a definite time. Adrenergic or D-receptor blockers were administered to inhibit the receptor stimulation mediated by DA. Hemodynamic changes were recorded and kidneys were harvested after 6 h of BD. Mean arterial pressure was completely normalized by DA treatment. DA pretreatment before BD induction and treatment during BD both significantly inhibited the monocyte infiltration. The anti-inflammatory as well as its blood pressure stabilizing effect was abrogated by concomitant application of adrenergic receptor blockers. In contrast, concomitant application of D-receptor blockers only abrogated the anti-inflammatory effect, but did not affect blood pressure stabilization. In contrast, pergolide and adrenergic receptor blockers completely normalized the blood pressure, but did not affect renal inflammation. Hence, DA might reduce BD-induced monocyte infiltration possibly by hemodynamic stabilization, D-receptor activation, or a combination of both.

Propofol increased the interleukin-6 to interleukin-10 ratio more than isoflurane after surgery in long-term alcoholic patients

This study investigated the effect of an anaesthetic regimen on the immune response in 40 long-term alcoholic patients undergoing surgery. Patients were randomly allocated to receive either propofol or isoflurane during surgery. Plasma cytokines interleukin (IL)-6 and IL-10 were measured at defined times and rates of post-operative infections were documented. The IL-6/IL-10 ratio significantly increased with propofol compared with isoflurane on day 1 after surgery and the IL-10 level significantly increased with isoflurane on day 1 after surgery. The overall post-operative infection rate was significantly higher in isoflurane-treated patients. Our findings indicate that propofol anaesthesia might be the more favourable regimen, with the IL-6/IL-10 ratio indicating an attenuation of the immune imbalance after surgery in long-term alcoholic patients. These results support the undertaking of a properly powered clinical trial to determine if propofol anaesthesia can reduce the postoperative infection rate in this special patient population.

Comparison of the Modulatory Effects of Four Different Fast-Track Anesthetic Techniques on the Inflammatory Response to Cardiac Surgery With Cardiopulmonary Bypass

OBJECTIVES

To test the hypothesis that the choice of anesthesia technique for coronary artery surgery influences the degree and magnitude of the subsequent inflammatory response and its consequences.

DESIGN

Prospective, randomized, comparative study.

SETTING

Major university teaching hospital.

PARTICIPANTS

Sixty patients undergoing elective surgery.

INTERVENTIONS

Patients were randomized into an alfentanil group, a high-dose remifentanil group, a low-dose remifentanil group, or a thoracic epidural group, in combination with a propofol target-controlled infusion. The study was blinded for the opioid, except in the epidural group. Tight control of perioperative hemodynamic parameters was maintained, and the postoperative management was strictly standardized. Bactericidal permeability-increasing protein as an indicator of the polymorphonuclear neutrophil response, interleukin-6 as an inducer of the acute-phase response, and lipopolysaccharide-binding protein and C-reactive protein as parameters of the acute phase response were determined at regular intervals. Ventilator dependency and analgesia were evaluated as clinical outcome measures.

MEASUREMENTS AND MAIN RESULTS

Interleukin-6 levels increased in all groups. Plasma levels in the epidural group were significantly higher at all time points than in the other groups. The increase in the plasma levels of bactericidal permeability-increasing protein, lipopolysaccharide-binding protein, and C-reactive protein showed the same pattern in all groups, and no significant differences among the 4 groups were observed.

CONCLUSIONS

Supplementation of a fast-track anesthetic technique with epidural analgesia preserves hemodynamic stability and is associated with faster extubation times (p = 0.003) and less postoperative pain (p = 0.045). Thoracic epidural analgesia was associated with significantly higher levels of IL-6 throughout the study period as compared with the total intravenous anesthesia groups. The exact clinical relevance of this finding remains unclear.

Immune suppression while awaiting surgery and following it: dissociations between plasma cytokine levels, their induced production, and NK cell cytotoxicity

Surgery may render patients susceptible to life-threatening complications, including infections and later metastases. Suppression of cell mediated immunity (CMI) and perturbations in the cytokine network were implicated in these outcomes. The current study assessed the effects of various surgeries on a wide array of immune indices, and compared patients' pre-operative immune status to that of control subjects. A total of 81 subjects (controls, moderate and major surgeries) provided up to five daily blood samples. Whole blood procedures were conducted within hours of blood withdrawal, assessing NK cell number and cytotoxicity, and plasma cytokine levels and induced production (IFNgamma, IL-6, IL-10, and IL-12). Our findings indicate that surgery reduced NK cell numbers/ml blood, and independently suppressed NK activity per NK cell and per ml blood. Among other perturbations in the cytokine network, pro-CMI cytokine production (IL-12 and IFNgamma) was reduced by surgery. Surprisingly, plasma levels of IFNgamma and IL-6 increased following surgery, while their in vitro induced production showed opposite effects. Patients awaiting surgery exhibited impaired IL-12 induced production and NK activity/ml, and reduced IFNgamma plasma levels. No significant associations were found between NK cytotoxicity and Th1 cytokines, although these indices showed high correlations with other variables. Overall, our findings indicate that patients exhibit impaired immune functions even before operation, which seem to contribute to the evident post-operative immune suppression. In the peri-operative context, induced cytokine production and plasma cytokines levels reflect different processes. Last, we suggest that peri-operative suppression of NK activity is mediated by neuroendocrine responses rather than Th1 cytokines.

ALTERATIONS IN INFLAMMATORY CAPACITY AND TLR EXPRESSION ON MONOCYTES AND NEUTROPHILS AFTER CARDIOPULMONARY BYPASS

Cardiopulmonary bypass (CPB) is associated with immune paresis, which predisposes to the development of postoperative sepsis. The aims of this study were to characterize the ex vivo cytokine responses to bacterial cell wall components in whole blood from patients undergoing CPB and to determine whether altered leukocyte expression of Toll-like receptors (TLRs) is involved in immune paresis after CPB. We recruited 6 patients undergoing routine cardiac surgery with CPB. Preoperatively, at the end of CPB and 20 h later, blood was obtained, anticoagulated, and leukocyte surface expression of CD14, TLR2, and TLR4 was quantified by flow cytometry. In addition, blood was incubated at 37 degrees C in the presence of peptidoglycan (PepG) and/or lipopolysaccharide (LPS), and plasma cytokines were measured by enzyme immunoassay. At the end of CPB, ex vivo production of tumor necrosis factor alpha, interleukin (IL) 1beta, IL-8, and IL-10 in response to PepG or LPS was virtually abolished (P < 0.05). The following day, there was recovery of all cytokine responses to PepG. Tumor necrosis factor alpha and IL-1beta responses to LPS partially recovered, whereas IL-8 and IL-10 responses recovered. At the end of CPB, there was more than 50% reduction in neutrophil TLR2 and TLR4 expression (P < 0.05), with recovery to baseline the following day. There was a 29% reduction in monocyte TLR4 expression at the end of CPB (P < 0.05) and more than 120% increase in monocyte TLR2 and 4 expression the following day (P < 0.05). In conclusion, reduced ex vivo production of cytokines cannot be fully accounted for by downregulation of TLR expression, although receptor upregulation may contribute to the later recovery of responsiveness.

The benefits of adding epidural analgesia to general anesthesia: a metaanalysis

The purpose of this metaanalysis was to determine the benefits of postoperative epidural analgesia in patients operated on under general anesthesia. By searching the American National Library of Medicine's Pubmed database from 1966 to July 10, 2004, 70 studies were identified. These included 5402 patients, of which 2660 had had epidural analgesia. Epidural analgesia reduces the incidence of arrhythmia, odds ratio (OR) = 0.59 (95%CI = 0.42, 0.81, P = 0.001); time to tracheal extubation, OR = -3.90 h (95%CI = -6.37, -1.42, P = 0.002); intensive care unit stay, OR = -2.94 h (95%CI = -5.66, -0.22, P = 0.03); visual analogical pain (VAS) scores at rest, OR = -0.78 (95%CI = -0.99, -0.57, P < 0.00001) and during movement, OR = -1.28 (95%CI = -1.81, -0.75, P < 0.00001); maximal blood epinephrine, OR = -165.70 pg.ml(-1) (95%CI = -252.18, -79.23, P = 0.0002); norepinephrine, OR = -134.24 pg.ml(-1) (95%CI = -247.92, -20.57, P = 0.02); cortisol, OR = -55.81 nmol.l(-1) (95%CI = -79.28, -32.34, P < 0.00001); and glucose concentrations achieved, OR = -0.87 nmol.l(-1) (95%CI = -1.37, -0.37, P = 0.0006). It also reduces the first 24-h morphine consumption, OR = -13.62 mg (95%CI = -22.70, -4.54, P = 0.003), and improves the forced vital capacity (FVC), OR = 0.23 l (95%CI = 0.09, 0.37, P = 0.001) at 24 h. A thoracic epidural containing a local anesthetic reduces the incidence of renal failure: OR = 0.34 (95%CI = 0.14, 0.81, P = 0.01). Epidural analgesia may thus offer many advantages over other modes of postoperative analgesia.

Sympathetic activation and inflammatory response in patients with subarachnoid haemorrhage

OBJECTIVE

The aim of this study was to evaluate the correlation between sympathetic nervous activation and the immune response in patients following subarachnoid haemorrhage (SAH).

DESIGN AND SETTING

Clinical study in a neurosurgical intensive care unit.

PATIENTS AND PARTICIPANTS

Fourteen patients with acute non-traumatic SAH were included. Fifteen healthy, age-matched volunteers served as controls for measurement of catecholamine spillover.

INTERVENTION

Blood sampling for C3a, C5b-9, IL-6, IL-8 and norepinephrine kinetic determination was made within 48 h, at 72 h and on the 7th-10th day after the SAH.

MEASUREMENTS AND RESULTS

SAH patients exhibited a profound increase in the rate of norepinephrine spillover to plasma at 48 h, 72 h and 7-10 days after the insult, 3-4 times that in healthy individuals. The plasma levels of C3a, IL-6 and C5b-9 were significantly elevated at 48 h, at 72 h and 7-10 days after the SAH, but the plasma level of IL-6 decreased significantly 7-10 days after the SAH. There was no relationship between the magnitude of sympathetic activation and the levels of inflammatory markers.

CONCLUSIONS

Following SAH a pronounced activation of the sympathetic nervous system and the inflammatory system occurs. The lack of significant association between the rate of spillover of norepinephrine to plasma and the plasma levels of inflammatory markers indicates that the two processes, sympathetic activation and the immune response, following SAH are not quantitatively linked. In spite of a persistent high level of sympathetic activation the plasma level of IL-6 decreased significantly one week after SAH.

Modulation of adipokines and cytokines in gestational diabetes and macrosomia

CONTEXT/OBJECTIVE

Not much is known about the implication of adipokines and different cytokines in gestational diabetes mellitus (GDM) and macrosomia. The purpose of this study was to assess the profile of these hormones and cytokines in macrosomic babies, born to gestational diabetic women.

DESIGN/SUBJECTS

A total of 59 women (age, 19-42 yr) suffering from GDM with their macrosomic babies (4.35 +/- 0.06 kg) and 60 healthy age-matched pregnant women and their newborns (3.22 +/- 0.08 kg) were selected.

METHODS

Serum adipokines (adiponectin and leptin) were quantified using an obesity-related multiple ELISA microarray kit. The concentrations of serum cytokines were determined by ELISA.

RESULTS

Serum adiponectin levels were decreased, whereas the concentrations of leptin, inflammatory cytokines, such as IL-6 and TNF-alpha, were significantly increased in gestational diabetic mothers compared with control women. The levels of these adipocytokines were diminished in macrosomic babies in comparison with their age-matched control newborns. Serum concentrations of T helper type 1 (Th1) cytokines (IL-2 and interferon-gamma) were decreased, whereas IL-10 levels were significantly enhanced in gestational diabetic mothers compared with control women. Macrosomic children exhibited high levels of Th1 cytokines and low levels of IL-10 compared with control infants. Serum IL-4 levels were not altered between gestational diabetic mothers and control mothers or the macrosomic babies and newborn control babies.

CONCLUSIONS

GDM is linked to the down-regulation of adiponectin along with Th1 cytokines and up-regulation of leptin and inflammatory cytokines. Macrosomia was associated with the up-regulation of Th1 cytokines and the down-regulation of the obesity-related agents (IL-6 and TNF-alpha, leptin, and adiponectin).

Endothelial Ca2+ signal transduction is altered by postoperative serum from patients undergoing coronary surgery with cardiopulmonary bypass

Endothelial dysfunction after surgery may be caused by alterations in the intracellular signaling properties of endothelial cells. Functional alterations are believed to be systemic and dependent on the amount of invasiveness. This led us to assume that there would be a mediator in the blood. Therefore, we investigated the influence of perioperative serum obtained from patients undergoing highly invasive surgical interventions (cardiac surgery [CS] with cardiopulmonary bypass) and less invasiveness (total joint arthroplasty [TJA]) on endothelial single cell Ca2+ responses. Aortic endothelial cells were incubated with preoperative and postoperative serum samples from 26 patients undergoing CS and from 15 patients undergoing TJA. Adenosine triphosphate (100 microM)-induced alterations in FURA-2 fluorescence was used to measure intracellular Ca2+ in single cells. In CS samples the induced [Ca2+]i signals were enhanced by postoperative serum (peak levels: 96 +/- 41 FU versus 116 +/- 45 FU; P < 0.05). These postoperative enhancements were absent in TJA patients serum. Preincubation of CS samples with nifedipine to block voltage gated Ca2+ channels did not alter this effect, but the absence of extracellular Ca2+ abolished the increased response from postoperative CS serum exposure. Ca2+ entry probed with Mn2+ quenching was increased in endothelial cells exposed with postoperative CS serum and Ca2+ entry correlated with postoperative circulating interleukin-6 levels (P < 0.007). Endothelial functional alterations after CS with cardiopulmonary bypass are attributable, in part, to systemic factors present in serum that lead to specific endothelial enhanced Ca2+-signaling. This enhancement can be separated in vitro as an increased Ca2+ entry not present in serum from patients recovering from TJA.

Induction of interleukin-19 and interleukin-22 after cardiac surgery with cardiopulmonary bypass

BACKGROUND

Interleukin (IL)-19, IL-20, and IL-22, three novel cytokines in the IL-10 family, have recently been discovered. The biological functions and clinical implications of these cytokines are not clear. We aimed to analyze if serum levels of these cytokines were altered in inflammatory responses of postoperative cardiopulmonary bypass (CPB) and investigate the molecular mechanism involved in cytokine induction.

METHODS

Twenty-five patients undergoing elective aortic-coronary bypass grafting with CPB were enrolled in this study. Blood samples withdrawn at (T1) before anesthesia, (T2) CPB start, (T3) CPB end, (T4) 4 hours post-CPB, (T5) 8 hours post-CPB, (T6) 12 hours post-CPB, (T7) 24 hours post-CPB, and (T8) 48 hours post-CPB were assayed for IL-6, IL-10, IL-19, IL-20, IL-22, and tumor necrotic factor-alpha (TNF-alpha). Transcripts of IL-19, IL-20, and IL-22 from monocytes were analyzed. In vitro, levels of IL-19, IL-20, and IL-22 production in monocytes incubated with IL-6 and TNF-alpha were determined.

RESULTS

The serum levels of IL-19 and IL-22 significantly increased at T3, peaked at T5, and remained increased at T8 (p<0.001). Induction of IL-19 and IL-22 was concomitant with the change in IL-10, IL-6, and TNF-alpha levels. Interleukin-19, IL-20, and IL-22 transcripts in monocytes from patients increased after CPB. In vitro experiments showed that IL-6 and TNF-alpha upregulated IL-19 protein expression in monocytes.

CONCLUSIONS

Serum IL-19 and IL-22 were induced in cardiac surgery with CPB and concomitant with induction of IL-6 and TNF-alpha. The IL-19 and these proinflammatory cytokines may interactively contribute to systemic inflammatory responses after CPB.

A randomized, double-blind, placebo-controlled study assessing the anti-inflammatory effects of ketamine in cardiac surgical patients

OBJECTIVE

To determine whether ketamine administration affects markers of inflammation in cardiac surgery with cardiopulmonary bypass (CPB) and to investigate differences between 2 low-dose ketamine regimens.

DESIGN

Prospective, randomized, placebo-controlled trial.

SETTING

Single-center university hospital.

PARTICIPANTS

Patients undergoing cardiac surgery with CPB.

INTERVENTION

Patients (n = 50) were randomized to 1 of 3 groups: ketamine, 0.25 mg/kg (n = 15); ketamine, 0.5 mg/kg (n = 18);or placebo (n = 17) in a double-blind manner at the time of induction of general anesthesia.

MEASUREMENTS AND MAIN RESULTS

Serum C-reactive protein (CRP) and interleukin (IL)-6, IL-8, and IL-10 were measured at baseline, on intensive care unit (ICU) arrival, and on the first postoperative day (POD 1). Both ketamine doses decreased the serum IL-6 response at ICU arrival and POD 1 compared with placebo (p < 0.05). CRP was lower in the 0.5-mg/kg group than placebo on POD 1 (p = 0.003). IL-10 was lower in the ketamine groups (p = 0.01) at POD 1 compared with placebo; IL-8 levels were not affected by ketamine. Mean arterial pressure and systemic vascular resistance were higher at the end of surgery, arrival in the ICU, and POD 1 in the ketamine groups (p < 0.05).

CONCLUSION

Low-dose ketamine (0.5 mg/kg) attenuates increases in CRP, IL-6, and IL-10 while decreasing vasodilatation after CPB.

Acute stress suppresses pro-inflammatory cytokines TNF-alpha and IL-1 beta independent of a catecholamine-driven increase in IL-10 production

Interleukin (IL)-10 is an anti-inflammatory cytokine that can down-regulate various aspects of the immune response. In this study we demonstrate that exposure to a psychophysiological stressor (swim stress) increases IL-10 production in female rats in response to an in vivo challenge with bacterial lipopolysaccharide (LPS). This increase in LPS-induced IL-10 was associated with suppression of the pro-inflammatory cytokines IL-1beta and TNF-alpha, indicating that overall, swim stress promotes an immunosuppressive cytokine phenotype. Despite the well-documented ability of IL-10 to suppress pro-inflammatory cytokine production, neutralisation of IL-10 failed to block the stress-induced suppression of IL-1beta and TNF-alpha. These data indicate that the suppressive effect of swim stress on these pro-inflammatory cytokines occurs independently of increased IL-10 production. To determine if swim stress-induced immunosuppression was mediated by increased sympathetic nervous system activity, and subsequent beta-adrenoceptor activation, we assessed the ability of the beta-adrenoceptor antagonist nadolol to block stressor-induced changes in cytokine production. Whilst pre-treatment with nadolol completely blocked the stress-induced increase in IL-10, it failed to alter the suppression of TNF-alpha or IL-1beta. Similarly, pre-treatment with the glucocorticoid receptor antagonist mifepristone also failed to attenuate the suppressive effect of swim stress on IL-1beta and TNF-alpha production. These data indicate that neither increased glucocorticoid secretion, nor catecholamine-induced beta-adrenoceptor activation, mediates the suppressive effect of swim stress on pro-inflammatory cytokine production. Taken together, these data demonstrate a role for beta-adrenoceptor activation in the ability of acute swim stress to increase LPS-induced IL-10 production, and also highlight a mechanistic dissociation between the ability of swim stress to increase IL-10 and suppress pro-inflammatory cytokine production.

Postoperative Epidural Anesthesia Preserves Lymphocyte, but Not Monocyte, Immune Function After Major Spine Surgery

Extensive spine surgery is associated with postsurgical pain. Epidural pain therapy may reduce postoperative stress responses and thereby influence immune functions. In a randomized, controlled, double-blinded prospective trial, 54 patients received either conventional patient-controlled IV analgesia (PCIA; morphine 3 mg/15 min) or patient-controlled epidural analgesia (PCEA; 0.125% ropivacaine plus sufentanil 1 microg/mL at a base rate of 12 mL/h and bolus application of 5 mL/15 min). Circulating cytokines, C-reactive protein (CRP), cortisol, and cell-surface receptor expression of immune cells (cluster of differentiation [CD]14, human leukocyte antigen-DR, CD86, CD71, CD3, CD4, CD8, CD16, and CD19) were measured perioperatively to characterize immunological functions. PCEA, compared with PCIA, had no influence on altered levels of circulating cytokines (interleukin (IL)-6, IL-8, IL-10, tumor necrosis factor-alpha, monocyte chemoattractant protein-1, and macrophage inhibitory factor) or indicators of the stress response (CRP and cortisol). Also, no significant difference was found in monocyte numbers or their human leukocyte antigen-DR, CD86, or CD71 expression. In contrast, the postoperative decrease in B lymphocytes and T-helper cells was significant in the PCEA group. Natural killer cells decreased significantly in patients receiving PCEA compared with PCIA. Therefore, postoperative epidural pain therapy has no influence on monocyte functions but reduces natural killer cells and preserves B-cell and T-helper cell populations. Epidural analgesia thus influences the specific rather than the innate immune system and potentially blunts the postsurgical lymphocyte depression, which is relevant for infectious resistance.

IMPLICATIONS

Epidural analgesia affects the immune system. Postoperative epidural analgesia, compared with conventional IV opioid therapy, preserves lymphocyte rather than monocyte functions. An improvement of postoperative immune function by epidural analgesia therefore may improve postoperative resistance to infectious complications or to chronic pain states.