[Perioperative atrial fibrillation : Diagnosis with underestimated relevance]

Atrial fibrillation (AF) is the most common cardiac arrhythmia in adults, both in general and perioperatively and is associated with significant morbidity and mortality. The age of the patients is a major risk factor. The prevalence of AF in noncardiac surgery (NCS) varies widely from 0.4% to 30% and for cardiac surgery, especially major combined procedures, up to approximately 50%. Ectopic excitation centers and reentry mechanisms at the atrial level are favored as the main process of uncoordinated electrical atrial activity. The loss of atrial contraction can lead to a reduction in cardiac output of up to 20-25%. The increased risk of thromboembolism due to AF extends beyond the perioperative period. Medication-based prevention strategies have not yet gained widespread acceptance. Treatment strategies include frequency and rhythm control as well as the avoidance of thromboembolisms through anticoagulation.

Effect of High-Dose Selenium on Postoperative Organ Dysfunction and Mortality in Cardiac Surgery Patients: The SUSTAIN CSX Randomized Clinical Trial

Importance

Selenium contributes to antioxidative, anti-inflammatory, and immunomodulatory pathways, which may improve outcomes in patients at high risk of organ dysfunctions after cardiac surgery.

Objective

To assess the ability of high-dose intravenous sodium selenite treatment to reduce postoperative organ dysfunction and mortality in cardiac surgery patients.

Design, Setting, and Participants

This multicenter, randomized, double-blind, placebo-controlled trial took place at 23 sites in Germany and Canada from January 2015 to January 2021. Adult cardiac surgery patients with a European System for Cardiac Operative Risk Evaluation II score-predicted mortality of 5% or more or planned combined surgical procedures were randomized.

Interventions

Patients were randomly assigned (1:1) by a web-based system to receive either perioperative intravenous high-dose selenium supplementation of 2000 μg/L of sodium selenite prior to cardiopulmonary bypass, 2000 μg/L immediately postoperatively, and 1000 μg/L each day in intensive care for a maximum of 10 days or placebo.

Main Outcomes and Measures

The primary end point was a composite of the numbers of days alive and free from organ dysfunction during the first 30 days following cardiac surgery.

Results

A total of 1416 adult cardiac surgery patients were analyzed (mean [SD] age, 68.2 [10.4] years; 1043 [74.8%] male). The median (IQR) predicted 30-day mortality by European System for Cardiac Operative Risk Evaluation II score was 8.7% (5.6%-14.9%), and most patients had combined coronary revascularization and valvular procedures. Selenium did not increase the number of persistent organ dysfunction-free and alive days over the first 30 postoperative days (median [IQR], 29 [28-30] vs 29 [28-30]; P = .45). The 30-day mortality rates were 4.2% in the selenium and 5.0% in the placebo group (odds ratio, 0.82; 95% CI, 0.50-1.36; P = .44). Safety outcomes did not differ between the groups.

Conclusions and Relevance

In high-risk cardiac surgery patients, perioperative administration of high-dose intravenous sodium selenite did not reduce morbidity or mortality. The present data do not support the routine perioperative use of selenium for patients undergoing cardiac surgery.

Trial Registration

ClinicalTrials.gov Identifier: NCT02002247.

[Proper Perioperative Handling of Continuous Medication in Patients with Cardiac Comorbidities]

Cardiac comorbidities place a significant burden on the German population. Every third adult is diagnosed with arterial hypertension (AHT). In 2017 congestive heart failure (CHF) pertained approximately 2,5 million of mandatory health-insured patients. Coronary artery disease (CAD) is diagnosed in 28,3% of men and 19,1% of women older than 65 years.For optimal perioperative care it is important to have a sound knowledge of current treatment strategies of cardiac comorbidities. This helps in gaining an optimal risk stratification of the individual patient. It also ensures an optimal anesthesiological perioperative care for the patient at hand. Recommendations for the perioperative discontinuation or continuation of cardiac active drugs vary between countries and responsible medical societies.This article provides an in-depth review of the current medical therapies for cardiac conditions like AHT, CHF or CAD. The varying recommendations for the perioperative discontinuation/continuation of these therapies are also reviewed.

[Vasopressin in distributive shock : Brief summary of the guidelines of the Canadian Critical Care Society published in December 2019]

The Canadian Critical Care Society performed a meta- analysis to assess the benefits and risks of the application of vasopressin and vasopressin- analogues in distributive shock. Their results were formulated as a Guideline in 2019. In the meta- analysis mainly included were studies with patients suffering from sepsis causing the distributive shock. The recommendations of the Surviving Sepsis Campaign 2016 concerning catecholamine therapy clearly prefer norepinephrin as the first- choice vasopressor, the use of vasopressin as an additionally administered drug is rated more tentative. Also the Canadian guideline now, implicating recently published studies, argues for the use of vasopressin or vasopressin- analogues in addition to an existing norepinephrine therapy, even though the level of evidence remains still low and there's no simple therapeutic algorithm formulated. This is based on a lowered incidence of newly- diagnosed atrial fibrillation and decreased mortality rate while administration remains safe.

EuroScore and IL-6 predict the course in ICU after cardiac surgery

BACKGROUND

Despite modern advances in intensive care medicine and surgical techniques, mortality rates in cardiac surgical patients are still about 3%. Considerable efforts were made to predict morbidity and mortality after cardiac surgery. In this study, we analysed the predictive properties of EuroScore and IL-6 for mortality in ICU, prolonged postoperative mechanical ventilation, and prolonged stay in ICU.

METHODS

We enrolled 2972 patients undergoing cardiac surgery. The patients either underwent aortic valve surgery (AV), mitral valve surgery (MV), coronary artery bypass grafting (CABG), and combined operations of aortic valve and coronary artery bypass grafting (AV + CABG) or of mitral and tricuspid valve (MV + TV). Different laboratory and clinical parameters were analysed.

RESULTS

EuroScore as well as IL-6 were associated with increased mortality after cardiac surgery. Furthermore, a higher EuroScore and elevated levels of IL-6 were predictors for prolonged mechanical ventilation and a longer stay in ICU. Especially, highly significant elevated IL-6 levels and an increased EuroScore showed a strong association. Statistics suggested superiority when both parameters were combined in a single model.

CONCLUSION

Our results suggest that EuroScore and IL-6 are helpful in predicting the course in ICU after cardiac surgery, and therefore, the use of intensive care resources. Especially, the combination of highly elevated levels of IL-6 and EuroScore may prove to be excellent predictors for an unfortunate postoperative course in ICU.

Non-invasive evaluation of macro- and microhemodynamic changes during induction of general anesthesia – A prospective observational single-blinded trial

BACKGROUND: Hypotension and bradycardia are known side effects of general anesthesia, while little is known about further macro- and microhemodynamic changes during induction. Intriguing is furthermore, why some patients require no vasopressor medication to uphold mean arterial pressure, while others need vasopressor support. OBJECTIVE: Determination of macro- and microhemodynamic changes during induction of general anesthesia. METHODS: We enrolled 150 female adults scheduled for gynaecological surgery into this prospective observational, single-blinded trial. Besides routinely measuring heart rate (HR) and mean arterial blood pressure (MAP), the non-invasive technique of thoracic electrical bioimpedance was applied to measure cardiac output (CO), cardiac index (CI), stroke volume (SV), stroke volume variability (SVV) and index of myocardial contractility (ICON) before induction of anesthesia, 7 times during induction, and, finally, after surgery in the recovery room. Changes in microcirculation were assessed using sidestream dark field imaging to establish the perfused boundary region (PBR), a validated gauge of glycocalyx health. Comparisons were made with Friedman’s or Wilcoxon test for paired data, and with Mann-Whitney-U test for unpaired data, with post-hoc corrections for multiple measurements by the Holm-Bonferroni method. RESULTS: 83 patients did not need vasopressor support, whereas 67 patients required therapy (norepinephrine, atropine or cafedrine/theodrenaline) to elevate MAP values to ≥70mmHg during induction, 54 of these receiving norepinephrine (NE) alone. Pre-interventional (basal) values of CO, CI, ICON, SV and SVV were all significantly lower in the group of patients later requiring NE (p < 0.04), whereas HR and MAP were identical for both groups. HR, MAP and CO decreased from baseline to 12 min after induction of general anesthesia in both the patients without and those with NE support. Heart rate decreased significantly by about 25% in both groups (–19 to –21 bpm). The median individual decrease of MAP amounted to –26.7% (19.7/33.3, p < 0.001) and –26.1% (11.6/33.2, p < 0.001), respectively, whereas for CO it was –40.7% (34.1/50.1, p < 0.001) and –43.5% (34.8/48.7). While these relative changes did not differ between the two groups, in absolute values there were significantly greater decreases in CO, CI, SV and ICON in the group requiring NE. Noteably, NE did not restore ICON or the other cardiac parameters to levels approaching those of the group without NE. PBR was measured in a total of 84 patients compiled from both groups, there being no intergroup differences. It increased 6.4% (p < 0.001) from pre-induction to the end of the operation, indicative of damage to microvascular glycocalyx. CONCLUSION: Non-invasive determination of CO provides additional hemodynamic information during anesthesia, showing that induction results in a significant decrease not only of MAP but also of CO and other cardiac factors at all timepoints compared to baseline values. The decrease of CO was greater than that of MAP and, in contrast to MAP, did not respond to NE. There was also no sign of a positive inotropic effect of NE in this situation. Support of MAP by NE must consequently result from an increase in peripheral arterial resistance, posing a risk for oxygen supply to tissue. In addition, general anesthesia and the operative stimulus lead to an impairment of the microcirculation.

Bilirubin and lactate: easy to determine and valuable to predict outcome in cardiac surgery

BACKGROUND

Cardiopulmonary bypass during cardiac surgery is associated with metabolic changes after operation and results inter alia in increased levels of lactate and bilirubin. Since prediction of the course after operation has become very important for the management of an ICU and the patients themselves, we evaluated easily assessable markers (lactate and bilirubin), regarding their potential to predict mortality 90 days after surgery and the length of stay in ICU.

METHODS

All patients within a period of five years undergoing cardiac surgery were enrolled in the study. Among others peak levels of lactate and bilirubin within 48 hours after operation were recorded. A Cox proportional hazard model as well as a logistic regression model were used to predict mortality or rather length of stay in ICU.

RESULTS

Increased levels of bilirubin and lactate were associated with a significantly increase in mortality and length of stay in ICU (in a concentration-related manner). Interestingly, creatinine serum levels before operation showed a similar performance.

CONCLUSIONS

Three easily assessable and cheap laboratory parameters (bilirubin, lactate, and creatinine) are useful to predict 90-day mortality and length of stay in ICU. These findings might be helpful to give patients a reliable prediction about short and mid-term-survival and to improve the management of an ICU.

Vasopressor Therapy in Cardiac Surgery-An Experts' Consensus Statement

Hemodynamic conditions with reduced systemic vascular resistance commonly are observed in patients undergoing cardiac surgery and may range from moderate reductions in vascular tone, as a side effect of general anesthetics, to a profound vasodilatory syndrome, often referred to as vasoplegic shock. Therapy with vasopressors is an important pillar in the treatment of these conditions. There is limited guidance on the appropriate choice of vasopressors to restore and optimize systemic vascular tone in patients undergoing cardiac surgery. A panel of experts in the field convened to develop statements and evidence-based recommendations on clinically relevant questions on the use of vasopressors in cardiac surgical patients, using a critical appraisal of the literature following the GRADE system and a modified Delphi process. The authors unanimously and strongly recommend the use of norepinephrine and/or vasopressin for restoration and maintenance of systemic perfusion pressure in cardiac surgical patients; despite that, the authors cannot recommend either of these drugs with respect to the risk of ischemic complications. The authors unanimously and strongly recommend against using dopamine for treating post-cardiac surgery vasoplegic shock and against using methylene blue for purposes other than a rescue therapy. The authors unanimously and weakly recommend that clinicians consider early addition of a second vasopressor (norepinephrine or vasopressin) if adequate vascular tone cannot be restored by a monotherapy with either norepinephrine or vasopressin and to consider using vasopressin as a first-line vasopressor or to add vasopressin to norepinephrine in cardiac surgical patients with pulmonary hypertension or right-sided heart dysfunction.

Interleukin-6 predicts inflammation-induced increase of Glucagon-like peptide-1 in humans in response to cardiac surgery with association to parameters of glucose metabolism

Objective

Glucagon-like peptide-1 (GLP-1) is an incretin hormone, which gets secreted in response to nutritional stimuli from the gut mediating glucose-dependent insulin secretion. Interestingly, GLP-1 was recently found to be also increased in response to inflammatory stimuli in an interleukin 6 (IL-6) dependent manner in mice. The relevance of this finding to humans is unknown but has been suggested by the presence of high circulating GLP-1 levels in critically ill patients that correlated with markers of inflammation. This study was performed to elucidate, whether a direct link exists between inflammation and GLP-1 secretion in humans.

Research design and methods

We enrolled 22 non-diabetic patients scheduled for cardiac surgery as a reproducible inflammatory stimulus with repeated blood sampling before and after surgery.

Results

Mean total circulating GLP-1 levels significantly increased in response to surgery from 25.5 ± 15.6 pM to 51.9 ± 42.7 pM which was not found in a control population. This was preceded by an early rise of IL6, which was significantly associated with GLP-1 under inflammatory but not basal conditions. Using repeated measure ANCOVA, IL6 best predicted the observed kinetics of GLP-1, followed by blood glucose concentrations and cortisol plasma levels. Furthermore, GLP-1 plasma concentrations significantly predicted endogenous insulin production as assessed by C-peptide concentrations over time, while an inverse association was found for insulin infusion rate.

Conclusion

We found GLP-1 secretion to be increased in response to inflammatory stimuli in humans, which was associated to parameters of glucose metabolism and best predicted by IL6.

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-016-0330-8) contains supplementary material, which is available to authorized users.

[Noninvasive Mechanical Ventilation in Acute Respiratory Failure]

The non-invasive ventilation (NIV) is widespread in the clinical medicine and has attained meanwhile a high value in the clinical daily routine. The application of NIV reduces the length of ICU stay and hospitalization as well as mortality of patients with hypercapnic acute respiratory failure. Patients with acute respiratory failure in context of a cardiopulmonary edema should be treated in addition to necessary cardiological interventions with continuous positive airway pressure (CPAP) or NIV. In case of other forms of acute hypoxaemic respiratory failure it is recommended the application of NIV to be limited to mild forms of ARDS as the application of NIV in severe forms of ARDS is associated with higher rates of treatment failure and mortality. In weaning process from invasive ventilation the NIV reduces the risk of reintubation essentially in hypercapnic patients. A delayed intubation of patients with NIV failure leads to an increase of mortality and should therefore be avoided. With appropriate monitoring in intensive care NIV can also be successfully applied in pediatric patients with acute respiratory insufficiency. Furthermore NIV can be useful within palliative care for reduction of dyspnea and improving quality of life. The aim of the guideline update is, taking into account the growing scientific evidence, to outline the advantages as well as the limitations of NIV in the treatment of acute respiratory failure in daily clinical practice and in different indications.

Routine use of corticosteroids to prevent inflammation response in cardiac surgery

Cardiac surgery, especially if it involves cardiopulmonary bypass, is associated with a severe systemic inflammatory response. It is characterized by complement activation and initiation of coagulation, fibrinolysis and kallikrein cascades. Consecutive activation of immunoregulatory cells results in an extensive release of pro- and anti-inflammatory cytokines. This inflammatory storm is related to organ dysfunction or failure and correlates with postoperative morbidity. In order to attenuate this deleterious inflammatory response in the perioperative period alternative surgical techniques, novel extracorporeal circulation devices and immunomodulatory pharmacological strategies are in focus of contemporary research. Since decades corticosteroids have been used and studied in patients undergoing cardiac surgery. Although it could be shown that glucocorticoids seem to change the pro-inflammatory cytokine profile in a favourable manner, it still remains controversial if this effect translates into a better clinical outcome. Several clinical trials have proclaimed an association between this inflammatory response and the incidence of major complications i.e, myocardial infarction and pulmonary complications, but until now they have failed to show conclusive results. This article describes the different types and recommended dose schemes of corticosteroids in the perioperative period of cardiac surgery along with the discussion of few patents. It will comment on potential side effects and review the effect on the postoperative outcome.

Glucocorticoid-endocannabinoid interaction in cardiac surgical patients: relationship to early cognitive dysfunction and late depression

BACKGROUND

Endocannabinoids (ECs) are rapidly acting immune-modulatory lipid-signaling molecules that are important for adaptation to stressful and aversive situations.They are known to interact with glucocorticoids and other stress-responsive systems. Maladaptation to acute or chronic stress represents a major risk factor for the development of psychiatric disorders. In the present study, we administered stress doses of hydrocortisone ina prospective, randomized, placebo-controlled double blind study in patients undergoing cardiac surgery (CS) to examine the relationship between the use of glucocorticoids, plasma EC levels, and the occurrence of early postoperative cognitive dysfunction (delirium) and of later development of depression.

METHODS

We determined plasma levels of the ECs anandamide and 2-arachidonoylglycerol (2-AG) in CS patients of the hydrocortisone (n=56) and the placebo group(n=55) preoperatively, at postoperative day (POD) 1, at intensive care unit discharge, and at 6 months after CS(n=68). Postoperative delirium was diagnosed according to Diagnostic and Statistical Manual of the American Psychiatric Association IVth Edition (DSM-IV) criteria, and depression was determined by validated questionnaires and a standardized psychological interview (Structured Clinical Interview for DSM-IV).

RESULTS

Stress doses of hydrocortisone did not affect plasma EC levels and the occurrence of delirium or depression. However, patients who developed deliriumon POD 1 had significantly lower preoperative 2-AG levels of the neuroprotective EC 2-AG (median values, 3.8 vs. 11.3ng/ml; p=0.03). Preoperative 2-AG concentrations were predictive of postoperative delirium (sensitivity=0.70;specificity=0.69; cutoff value=4.9 ng/ml; receiver operating characteristic curve area=0.70; 95 o/o confidence interval=0.54-0.85). Patients with depression at 6 months after CS (n=16) had significantly lower anandamide and 2-AG levels during the perioperative period.

CONCLUSIONS

A low perioperative EC response may indicate an increased risk for early cognitive dysfunction and long-term depression in patients after CS. Glucocorticoids do not seem to influence this relationship.

Indocyanine green clearance after cardiac surgery: the impact of cardiopulmonary bypass

Plasma clearance of indocyanine green has recently been established as a tool to monitor hepatic function and perfusion non-invasively. Reduced indocyanine green clearance has been associated with adverse outcome in cardiac surgery patients, and cardiopulmonary bypass has been hypothesized to be one important triggering factor. We performed a prospective observational study comparing the influence of off-pump and on-pump coronary surgery on perioperative indocyanine green clearance. Twenty-five consecutive adult patients without known pre-existing hepatic diseases scheduled for off-pump coronary artery bypass grafting were evaluated for hepatic dysfunction pre- and postoperatively with serial measurements of indocyanine green plasma clearance, specific laboratory values and liver function scores. Twenty-five matched patients who underwent coronary artery bypass grafting surgery with cardiopulmonary bypass in the same period served as controls. Parameters of postoperative hepatic function, including measurements of indocyanine green plasma clearance and specific laboratory values and scores, did not differ significantly between patients undergoing off-pump coronary artery bypass grafting and patients undergoing coronary artery bypass grafting with extracorporeal circulation. In patients without pre-existing hepatic diseases, a significant influence of cardiopulmonary bypass on perioperative indocyanine green plasma clearance as well as on liver specific laboratory parameters and scores cannot be proven.

Stress doses of hydrocortisone reduce systemic inflammatory response in patients undergoing cardiac surgery without cardiopulmonary bypass

BACKGROUND

Systemic inflammatory response occurs after cardiac surgery (CS) and leads to a worse outcome in many cases. Stress doses of hydrocortisone have been successfully used to reduce SIRS and to improve outcome of patients after CS with cardiopulmonary bypass grafting (on-pump CABG), but the effect of hydrocortisone on patients undergoing CS without cardiopulmonary bypass grafting (off-pump CABG) is unclear. Therefore, we evaluated the effect of stress doses of hydrocortisone in this group of patients.

METHODS

A total of 305 patients undergoing off-pump CABG were enrolled in a prospective randomized trial according to the study protocol. The patients either received stress doses of hydrocortisone or placebo. We measured various laboratory and clinical variables characterizing the patients' outcomes.

RESULTS

The two study groups did not differ with regard to demographic data. Patients receiving hydrocortisone had an increased Higgins score and a decreased ejection fraction. Furthermore, patients from the hydrocortisone group had significantly lower levels of IL-6 (275 [162/677] pg/mL vs. 450 [320/660] pg/mL, P=0.001) and a shorter stay in the ICU (1 [1/3] day vs. 2 [2/3] days, P=0.04). Both groups did not differ in regard to catecholamine support, duration of mechanical ventilation, incidence of postoperative atrial fibrillation, blood loss, and mortality rate.

CONCLUSION

We conclude that intravenous stress doses of hydrocortisone lead to a reduction of systemic inflammation and to a potential improvement in the early outcome of patients undergoing off-pump CABG.

Serum concentrations of cortisol, interleukin 6, leptin and adiponectin predict stress induced insulin resistance in acute inflammatory reactions

Introduction

Inflammatory stimuli are causative for insulin resistance in obesity as well as in acute inflammatory reactions. Ongoing research has identified a variety of secreted proteins that are released from immune cells and adipocytes as mediators of insulin resistance; however, knowledge about their relevance for acute inflammatory insulin resistance remains limited. In this study we aimed for a clarification of the relevance of different insulin resistance mediating factors in an acute inflammatory situation.

Methods

Insulin resistance was measured in a cohort of 37 non-diabetic patients undergoing cardiac surgery by assessment of insulin requirement to maintain euglycaemia and repeated measurements of an insulin glycaemic index. The kinetics of cortisol, interleukin 6 (IL6), tumour necrosis factor α (TNFα), resistin, leptin and adiponectin were assessed by repeated measurements in a period of 48 h.

Results

Insulin resistance increased during the observation period and peaked 22 h after the beginning of the operation. IL6 and TNFα displayed an early increase with peak concentrations at the 4-h time point. Serum levels of cortisol, resistin and leptin increased more slowly and peaked at the 22-h time point, while adiponectin declined, reaching a base at the 22-h time point. Model assessment identified cortisol as the best predictor of insulin resistance, followed by IL6, leptin and adiponectin. No additional information was gained by modelling for TNFα, resistin, catecholamine infusion rate, sex, age, body mass index (BMI), operation time or medication.

Conclusions

Serum cortisol levels are the best predictor for inflammatory insulin resistance followed by IL6, leptin and adiponectin. TNFα, and resistin have minor relevance as predictors of stress dependent insulin resistance.

Indications and practical use of replacement dose of corticosteroids in critical illness

PURPOSE OF REVIEW

Ongoing and severe systemic inflammation affecting critically ill patients may cause adrenal insufficiency and steroid resistance in target cells. As the appropriate diagnosis of this clinical entity remains a challenge, indication and practical use of corticosteroid replacement therapy in the critically ill is generally directed by clinical symptoms and features.

RECENT FINDINGS

In the last 2 years, a series of clinical trials have been undertaken to investigate corticosteroid replacement therapy in critically ill patients with severe systemic inflammation of various origin. Improvements of morbidity have been demonstrated in some studies. The data of recent studies should lead to a restriction of corticosteroid replacement therapy in critically ill patients. The purpose of this review is to investigate indications and the best current practical use of corticosteroid replacement therapy in critically ill patients in the absence of accurate laboratory assessment of adrenal insufficiency.

SUMMARY

Corticosteroid replacement therapy may improve morbidity and mortality in specific target groups of critically ill patients. The appropriate target groups remain to be refined. To demonstrate this, additional studies are required on endocrine disorder in critical illness and corticosteroid replacement therapy.

Fibrin glue in coronary artery bypass grafting operations: casting out the Devil with Beelzebub?

OBJECTIVE

Fibrin sealants are frequently used in aortocoronary bypass operations. Although they are considered to be clinically safe, we performed a retrospective analysis of our data to examine the possible side effects of Tissucol fibrin sealant, namely the acute thrombosis of grafts and native coronary arteries resulting in severe myocardial damage and patient deaths.

METHODS

The data of 2716 patients (2001 male, 715 female) who received an aortocoronary bypass operation from November 1995 to December 1999 were studied retrospectively. Two groups (group 1: received Tissucol, group 2: no sealant used) were compared with respect to an a priori selected set of demographic and clinical variables and with respect to their effect on the outcome using bivariate tabulation. Multiple exploratory assessments of factors possibly related to fatal outcome were done by multiple logistic regression.

RESULTS

Nine hundred ninety patients (group 1) received Tissucol, 1726 patients (group 2) did not receive it. Mean patient age was 64+/-9.1 years. Group 1 had a higher risk of death (7.8% vs 2.8%, p<0.001). The peak values of creatine kinase >500 and creatine kinase-myocardial band >50 were higher in group 1 than in group 2, p<0.001. Adjusted odds ratios for the risk of fatal outcome were: 2.01 for the use of Tissucol, 2.71 for patient age >70 years, 2.02 for aortic cross clamp time >90 min, 3.95 for postoperative ventricular fibrillation, 6.35 for postoperative cardiopulmonary resuscitation, 4.55 for postoperative aortocoronary reoperation.

CONCLUSION

In our analysis an increased risk of myocardial injury or even death was found in coronary artery bypass grafting patients when Tissucol fibrin sealant was used intraoperatively.

Goal-directed fluid management reduces vasopressor and catecholamine use in cardiac surgery patients

OBJECTIVE

We examined whether guiding therapy by an algorithm based on optimizing the global end-diastolic volume index (GEDVI) reduces the need for vasopressor and inotropic support and helps to shorten ICU stay in cardiac surgery patients.

DESIGN AND SETTING

Single-center clinical study with a historical control group at an university hospital.

PATIENTS

Forty cardiac bypass surgery patients were included prospectively and compared with a control group.

INTERVENTIONS

In the goal-directed therapy (GDT) group hemodynamic management was guided by an algorithm based on GEDVI. Hemodynamic goals were: GEDVI above 640 ml/m2, cardiac index above 2.5 l/min/m2, and mean arterial pressure above 70 mmHg. The control group was treated at the discretion of the attending physician based on central venous pressure, mean arterial pressure, and clinical evaluation.

RESULTS

In the GDT group duration of catecholamine and vasopressor dependence was shorter (187+/-70 vs. 1458+/-197 min), and fewer vasopressors (0.73+/-0.32 vs. 6.67+/-1.21 mg) and catecholamines (0.01+/-0.01 vs. 0.83+/-0.27mg) were administered. They received more colloids (6918+/-242 vs. 5514+/-171ml). Duration of mechanical ventilation (12.6+/-3.6 vs. 15.4+/4.3 h) and time until achieving status of fit for ICU discharge (25+/-13 vs. 33+/-17h) was shorter in the GDT group.

CONCLUSIONS

Guiding therapy by an algorithm based on GEDVI leads to a shortened and reduced need for vasopressors, catecholamines, mechanical ventilation, and ICU therapy in patients undergoing cardiac surgery.

Association between vasopressor dependence and early outcome in patients after cardiac surgery

Arterial hypotension with vasopressor dependence is a major problem after cardiac surgery. We evaluated the early postoperative course of 1558 consecutive patients scheduled for cardiac surgery, and compared the outcome of patients with and without vasopressor dependence (defined as the need for > 0.1 microg x kg(-1) x h(-1) noradrenaline for > 3 h in the face of normovolaemia). Vasopressor dependence was diagnosed in 424 patients (27%) and was associated with a higher incidence of postoperative renal failure (67 (15.7%) vs 7 (0.6%), respectively; p < 0.0001), a longer duration of ventilation (median IQR [range]) 14 (8-26 [6-39]) h vs 8 (5-11 [4-32]) h; p < 0.0001), a greater need for red cell transfusion (3 (1-5 [0-10]) units vs 1 (0-2 [0-4]) units; p < 0.001) and a longer length of stay in the ICU (4 (2-6 [2-9] days) vs 2 (1-3 [1-6] days; p < 0.001). Vasopressor dependence could be predicted from a combination of factors, including pre-operative ejection fraction < 37%, cardiopulmonary bypass lasting > 94 min, and postoperative interleukin-6 > 837 pg x ml(-1).

Stress doses of hydrocortisone reduce chronic stress symptoms and improve health-related quality of life in high-risk patients after cardiac surgery: A randomized study

OBJECTIVES

Improvement in health-related quality of life is a major object of cardiac surgery. However, high stress exposure during the perioperative period of cardiac surgery can result in the formation of traumatic memories and symptoms of chronic stress or even posttraumatic stress disorder, which can have negative effects on health-related quality-of-life outcome. In this controlled study we examined whether exogenously administered stress doses of hydrocortisone during cardiac surgery reduce perioperative stress exposure and the long-term incidence of chronic stress symptoms and improve health-related quality of life after cardiac surgery.

METHODS

Thirty-six high-risk patients undergoing cardiac surgery were prospectively randomized to receive either stress doses of hydrocortisone or placebo. Of 28 available patients at 6 months after cardiac surgery, 14 had received hydrocortisone, and 14 had received placebo. Traumatic memories, chronic stress symptoms (posttraumatic stress disorder scores), and health-related quality of life were measured by using validated questionnaires.

RESULTS

Compared with patients from the placebo group, patients from the hydrocortisone group had a significantly shorter duration of intensive care unit treatment, required lower doses of the stress hormone norepinephrine during cardiac surgery, and had significantly fewer stress symptoms and a better health-related quality of life regarding physical function, chronic pain, general health, vitality, and mental health during follow-up. The groups did not differ with regard to the number or type of intensive care unit-related traumatic memories.

CONCLUSIONS

The use of stress doses of hydrocortisone in high-risk cardiac surgical patients reduces perioperative stress exposure, decreases chronic stress symptoms, and improves health-related quality of life at 6 months after cardiac surgery.

Assessing fluid responsiveness during open chest conditions

BACKGROUND

Measurement of ventilation-induced left ventricular stroke volume variations (SVV) or pulse pressure variations (PPV) is useful to optimize preload in patients after cardiac surgery. The aim of this study was to investigate the ability of SVV and PPV measured by arterial pulse contour analysis to assess fluid responsiveness in patients undergoing coronary artery bypass surgery during open-chest conditions.

METHODS

We studied 22 patients immediately after midline sternotomy. We determined SVV, PPV, left ventricular end-diastolic area index by transoesophageal echocardiography, global end-diastolic volume index and cardiac index by thermodilution before and after removal of blood 500 ml and after volume substitution with hydroxyethyl starch 6%, 500 ml.

RESULTS

Blood removal resulted in a significant increase in SVV from 6.7 (2.2) to 12.7 (3.8)%. PPV increased from 5.2 (2.5) to 11.9 (4.6)% (both P<0.001). Cardiac index decreased from 2.9 (0.6) to 2.3 (0.5) litres min(-1) m(-2) and global end-diastolic volume index decreased from 650 (98) to 565 (98) ml m(-2) (both P<0.025). Left ventricular end-diastolic area index did not change significantly. After fluid loading SVV decreased significantly to 6.8 (2.2)% and PPV decreased to 5.4 (2.1)% (both P<0.001). Concomitantly, cardiac index increased significantly to 3.3 (0.5) litres min(-1) m(-2) (P<0.001) and global end-diastolic volume index increased significantly to 663 (104) ml m(-2) (P<0.005). Left ventricular end-diastolic area index did not change significantly. We found a significant correlation between the increase in cardiac index caused by fluid loading and SVV as well as PPV before fluid loading (SVV, R=0.74, P<0.001; PPV, R=0.61, P<0.005). No correlations were found between values of global end-diastolic volume index or left ventricular end-diastolic area index before fluid loading and the increase in cardiac index.

CONCLUSION

Measurement of SVV or PPV allows assessment of fluid responsiveness in hypovolaemic patients under open-chest and open-pericardium conditions. Thus, measuring heart-lung interactions may improve haemodynamic management during surgical procedures requiring mid-line sternotomy.

Effects of mid‐line thoracotomy on the interaction between mechanical ventilation and cardiac filling during cardiac surgery

BACKGROUND

Mid-line thoracotomy is a standard approach for cardiac surgery. However, little is known how this surgical approach affects the interaction between the circulation and mechanical ventilation. We studied how mid-line thoracotomy affects cardiac filling volumes and cardiovascular haemodynamics, particularly variations in stroke volume and pulse pressure caused by mechanical ventilation.

METHODS

We studied 19 patients during elective coronary artery bypass surgery. Before and after mid-line thoracotomy, we measured arterial pressure, cardiac index (CI) and global end-diastolic volume index (GEDVI) by thermodilution, left ventricular end-diastolic area index (LVEDAI) by transoesophageal echocardiography and the variations in left ventricular stroke volume and pulse pressure during ventilation by arterial pulse contour analysis.

RESULTS

After thoracotomy, CI increased from 2.3 (0.4) to 2.9 (0.6) litre min(-1) m(-2), GEDVI increased from 605 (110) to 640 (94) litre min(-1) m(-2), and LVEDAI increased from 9.2 (3.7) to 11.2 (4.1) cm(2) m(-2). All these changes were significant. In contrast, stroke volume variation (SVV) decreased from 10 (3) to 6 (2)% and pulse pressure variation (PPV) decreased from 11 (3) to 5 (3)%. Before thoracotomy, SVV and PPV significantly correlated with GEDVI (both P<0.01). When the chest was open, similar significant correlations of SVV (P<0.001) and PPV (P<0.01) were found with GEDVI.

CONCLUSION

Thoracotomy increases cardiac filling and preload. Further, thoracotomy reduces the effect of mechanical ventilation on left ventricular stroke volume. However, also under open chest conditions, SVV and PPV are preload-dependent.

Stress doses of hydrocortisone, traumatic memories, and symptoms of posttraumatic stress disorder in patients after cardiac surgery: a randomized study

BACKGROUND

Traumatic experiences associated with cardiac surgery (CS) can result in traumatic memories and posttraumatic stress disorder (PTSD). Because it is known that subjects who develop PTSD often show sustained reductions in circulating cortisol concentrations, we performed a prospective, randomized study to examine whether exogenously administered stress doses of hydrocortisone during the perioperative period of CS reduces the long-term incidence of chronic stress and PTSD symptoms.

METHODS

Patients (n = 91) were prospectively randomized to receive either stress doses of hydrocortisone or standard treatment during the perioperative period of CS. Of 48 available patients at 6 months after CS, 26 had received stress doses of hydrocortisone and 22 standard treatment. Traumatic memories and PTSD symptoms were diagnosed with previously validated questionnaires.

RESULTS

As compared with patients after standard therapy, patients from the hydrocortisone group had significantly lower chronic stress symptom scores (p <.05). There was no significant difference regarding the number or type of traumatic memories between the hydrocortisone and the standard treatment groups.

CONCLUSIONS

Stress doses of hydrocortisone in patients undergoing CS are associated with a lower intensity of chronic stress and PTSD symptoms at 6 months after CS.

Surgical treatment of permanent atrial fibrillation using microwave energy ablation: a prospective randomized clinical trial

OBJECTIVE

Radiofrequency or the use of microwave energy in combination with atrial size reduction during open heart surgery have been reported to be effective in up to 75% in the treatment of permanent atrial fibrillation. However, no data from prospective randomized trials using microwave energy are available.

METHODS

Forty-three patients with permanent atrial fibrillation undergoing open-heart surgery were randomly stratified into treatment group receiving microwave ablation and atrial size reduction (n=24) or control group (n=19). Patients in either group were treated with amiodarone or sotalol for 3 months if sinus rhythm or any atrioventricular rhythm was successfully restored. Follow-up time points were at 3, 6 and 12 month after surgery.

RESULTS

In the treatment group 22 out of 24 patients (91,7%) were successfully converted to sinus rhythm by using intraoperative microwave ablation therapy whereas only six out of 19 (31.5%) patients converted to sinus rhythm directly after surgery. At 12-month follow-up there were still a significantly higher percentage of patients in the treatment group free from atrial fibrillation when compared to control (80 vs. 33.3%, P=0.036).

CONCLUSION

The preliminary data from this first prospectively randomized trial indicate that microwave ablation combined with atrial size reduction is a safe and highly efficient treatment in permanent atrial fibrillation.

Usefulness of left ventricular stroke volume variation to assess fluid responsiveness in patients with reduced cardiac function

OBJECTIVE

Stroke volume variation as measured by the analysis of the arterial pressure waveform enables prediction of volume responsiveness in ventilated patients with normal cardiac function. The aim of this study was to investigate the ability of monitoring stroke volume variation to predict volume responsiveness and to assess changes in preload in patients with reduced left ventricular function after cardiac surgery.

DESIGN

Prospective study.

SETTING

University hospital.

PATIENTS

Fifteen mechanically ventilated patients with a left ventricular ejection fraction <0.35 (study group) and 15 patients with an ejection fraction >0.50 (control group) after coronary artery bypass grafting following admission to the intensive care unit.

INTERVENTIONS

Volume loading with 10 mL of hetastarch 6% times body mass index. If stroke volume index increased >5%, successive volume loading was performed until no further increase in stroke volume index was reached.

MEASUREMENTS AND MAIN RESULTS

Stroke volume variation, central venous pressure, pulmonary artery occlusion pressure (PAOP), and left ventricular end-diastolic area index (LVEDAI) were measured at baseline and immediately after each volume loading step. In both groups, stroke volume variation at baseline correlated significantly with changes in stroke volume index caused by volume loading (p <.01). Further, changes in stroke volume variation as a result of volume loading correlated significantly with the concomitant changes in stroke volume index in both groups (p <.01). Using receiver operating characteristic analysis, in the study group areas under the curve for stroke volume variation, PAOP, central venous pressure, and LVEDAI did not differ significantly. In the control group, the area under the curve for stroke volume variation was statistically larger than for PAOP, central venous pressure, and LVEDAI.

CONCLUSIONS

Continuous and real-time monitoring of stroke volume variation by pulse contour analysis can predict volume responsiveness and allows real-time assessment of the hemodynamic effect of volume expansion in patients with reduced left ventricular function after cardiac surgery.

Effects of phospholipid-coated extracorporeal circuits on clinical outcome parameters and systemic inflammatory response in coronary artery bypass graft patients

INTRODUCTION

The use of extracorporeal circulation (ECC) during coronary artery bypass graft (CABG) surgery is associated with a systemic inflammatory response due to the contact of blood with artificial surfaces. The clinical relevance of ECC-related systemic inflammation varies with the patient, and such inflammation may be accompanied by intermittent organ dysfunction and an increased catecholamine requirement. We investigated the effects of a new phospholipid coating system of ECC on systemic inflammatory response and clinical outcome following CABG.

METHODS

Patients scheduled for CABG surgery were prospectively divided randomly into 2 patient groups: patients using noncoated ECC materials and patients using phospholipid-coated ECC materials. Clinical data measured perioperatively included hemodynamics, aortic clamp time, duration of bypass, time to extubation, catecholamine requirement, length of intensive care unit (ICU) stay, postoperative blood loss, and amount of blood transfused. In addition, blood samples were collected before cannulation and at 2, 24, and 48 hours postoperative. Cytokines (tumor necrosis factor alpha [TNF-alpha] and interleukin 10 [IL-10]) and P-selectin were measured with an enzyme-linked immunosorbent assay. Plasma nitrate/nitrite levels (NOx) were determined by the Griess reaction.

RESULTS

A significant increase of TNF-a level was noted in the uncoated control group only. In the uncoated group, IL-10 levels significantly increased at 2 hours postoperative, whereas levels remained unchanged in the phospholipid coating group. P-selectin increased 2 hours postoperative in the uncoated group, and no significant changes were noted in the phospholipid coating group. At 24 hours postoperative, total plasma NOx production significantly increased in the phospholipid coating group but remained constant in the control group. No significant differences with respect to postoperative parameters (time to extubation, ICU stay, amount of bleeding, blood transfused, and catecholamine requirement) were observed.

CONCLUSIONS

Phospholipid coating significantly reduces the systemic increase in proinflammatory and anti-inflammatory cytokines and P-selectin. Despite the comparable clinical outcomes in this study, the observed significant reduction in systemic inflammatory parameter values suggests an improved biocompatibility of ECC materials when they are coated with phospholipids.