Search

Extracorporeal support systems for the heart and lungs are employed for cardiac, pulmonary and also cardiopulmonary failure; however, neither the pure lung support by venovenous extracorporeal membrane oxygenation (vvECMO) nor the venoarterial (va) ECMO behave in a hemodynamically inert manner with respect to the patient's own cardiovascular system. The success of ECMO treatment is decisively dependent on monitoring before and during the execution and the pathophysiological understanding of the hemodynamic changes that occur during treatment. This article explicitly elucidates these "concomitant phenomena" and discusses fundamental aspects of cardiovascular physiology and the specific interplay with ECMO treatment.Extrakorporale Unterstützungssysteme von Herz und Lunge werden bei kardialem, pulmonalem oder auch kardiopulmonalem Versagen eingesetzt. Jedoch verhält sich weder die rein lungenunterstützende venovenöse extrakorporale Membranoxygenierung (vv-ECMO) noch die venoarterielle (va‑)ECMO hämodynamisch „inert“ gegenüber dem patienteneigenen Herz-Kreislauf-System. Der Erfolg einer ECMO-Therapie hängt entscheidend vom Monitoring vor und während der Durchführung sowie dem pathophysiologischen Verständnis für die hämodynamischen Veränderungen, die während der Therapie auftreten, ab. Der vorliegende Beitrag erläutert gezielt diese „Begleiterscheinungen“ und diskutiert fundamentale Aspekte der Herz-Kreislauf-Physiologie und ihr spezifisches Zusammenspiel mit einer ECMO-Therapie.

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.

Levosimendan steigert die myokardiale Kontraktilitat ohne relevante Erhohung des myozytaren Sauerstoffverbrauchs und besitzt kardioprotektive Eigenschaften. Es gibt Hinweise, dass diese Effekte auch durch geringere Dosierungen als durch die Standarddosis von 12,5 mg erreicht werden. Daher wurde herzchirurgischen Patienten mit einer praoperativen linksventrikularen Ejektionsfraktion (LVEF) ≤40 % nach Narkoseinduktion 1,25 mg Levosimendan zur pharmakologischen Prakonditionierung verabreicht. Eine individuelle weiterfuhrende Therapie mit Repetitionsdosen von Levosimendan erfolgte postoperativ auf der Intensivstation. In der vorliegenden Auswertung sollte untersucht werden, ob die Prakonditionierung mit 1,25 mg Levosimendan postoperativ den Bedarf an weiteren Inotropika, die Inzidenz von neu auftretendem Vorhofflimmern, mechanischer Kreislaufunterstutzung oder Nierenersatzverfahren, die Aufenthaltsdauer auf der Intensivstation sowie die 30-Tage-Letalitat beeinflusste. Weiterhin sollte erfasst werden, welche kumulative Levosimendandosis durch das Konzept der individualisierten Dosierung benotigt wurde. Diese retrospektive Untersuchung umfasst Patienten mit einer LVEF ≤40 %, die sich an unserer Einrichtung im Zeitraum vom Januar 2015 bis Dezember 2018 einem herzchirurgischen Eingriff unterzogen und zur Prophylaxe eines postoperativen myokardialen Pumpversagens nach Narkoseeinleitung 1,25 mg Levosimendan erhalten hatten. Basierend auf Echokardiographiebefunden, erweitertem hamodynamischem Monitoring sowie zentral- bzw. gemischt-venoser Sauerstoffsattigung und Lactat-Clearance konnten postoperativ weitere Gaben von Levosimendan verabreicht werden, bis die fur den jeweiligen Patienten benotigte Dosis zur kardiovaskularen Stabilisierung erreicht wurde. Die Ergebnisse wurden der aktuellen Literatur gegenubergestellt. Wir konnten 183 Patienten mit einer LVEF ≤40 % identifizieren, die eine pharmakologische Prakonditionierung mit 1,25 mg Levosimendan erhalten hatten. Postoperativ lagen die Maximaldosis von Adrenalin, die Inzidenz von Vorhofflimmern, die Notwendigkeit von Nierenersatzverfahren sowie die 30-Tage-Letalitat unter den publizierten Werten entsprechender Vergleichskollektive. Bei 73,2 % der Patienten war eine kumulative Levosimendandosis von 5 mg oder weniger als ausreichend erachtet worden. Das hier vorgestellte Konzept der pharmakologischen Prakonditionierung mit 1,25 mg Levosimendan, gefolgt von individualisierter Repetitionsdosierung, weist darauf hin, dass bei herzchirurgischen Patienten mit praoperativer LVEF ≤40 % die Verabreichung von Levosimendan im Vergleich zu aktueller Literatur mit moglichen Vorteilen bezuglich des postoperativen Inotropikabedarfs, des Auftretens von Vorhofflimmern, des Bedarfs an Nierenersatzverfahren und der 30-Tage-Letalitat einhergehen kann. Diese individualisierte Gabe von Levosimendan zur Unterstutzung der Hamodynamik und zur zugigen Dekatecholaminisierung sollte in randomisierten Studien uberpruft werden.

This case-control study investigated the long-term evolution of multidrug-resistant bacteria (MDRB) over a 5-year period associated with the use of selective oropharyngeal decontamination (SOD) in the intensive care unit (ICU). In addition, effects on health care-associated infections and ICU mortality were analysed.We investigated patients undergoing mechanical ventilation 48 h in 11 adult ICUs located at 3 campuses of a university hospital. Administrative, clinical, and microbiological data which were routinely recorded electronically served as the basis. We analysed differences in the rates and incidence densities (ID, cases per 1000 patient-days) of MDRB associated with SOD use in all patients and stratified by patient origin (outpatient or inpatient). After propensity score matching, health-care infections and ICU mortality were compared.5034 patients were eligible for the study. 1694 patients were not given SOD. There were no differences in the incidence density of MDRB when SOD was used, except for more vancomycin-resistant Enterococcus faecium (0.72/1000 days vs. 0.31/1000 days, p 0.01), and fewer ESBL-producing Klebsiella pneumoniae (0.22/1000 days vs. 0.56/1000 days, p 0.01). After propensity score matching, SOD was associated with lower incidence rates of ventilator-associated pneumonia and death in the ICU but not with ICU-acquired bacteremia or urinary tract infection.Comparisons of the ICU-acquired MDRB over a 5-year period revealed no differences in incidence density, except for lower rate of ESBL-producing Klebsiella pneumoniae and higher rate of vancomycin-resistant Enterococcus faecium with SOD. Incidence rates of ventilator-associated pneumonia and death in the ICU were lower in patients receiving SOD.

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.Arterielle Hypertonie, Herzinsuffizienz und koronare Herzerkrankung kann man in Deutschland als Volkskrankheiten betrachten. Somit ist der Anästhesist täglich mit Patienten konfrontiert, die kardial wirksame Medikamente einnehmen. Welche soll man perioperativ weiter verabreichen und welche besser pausieren? Dieser Beitrag stellt hierzu internistische Behandlungskonzepte und den perioperativen Umgang mit kardialen Medikamenten vor.

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.

Objectives Cardiopulmonary bypass is associated with severe immune dysfunctions. Particularly, a cardiopulmonary bypass-related long-lasting immunosuppressive state predisposes patients to a higher risk of postoperative complications, such as persistent bacterial infections. This study was conducted to elucidate mechanisms of post-cardiopulmonary bypass immunosuppression. Design In vitro studies with human peripheral blood mononuclear cells. Setting Cardiosurgical ICU, University Research Laboratory. Patients Seventy-one patients undergoing cardiac surgery with cardiopulmonary bypass (enrolled May 2017 to August 2018). Interventions Peripheral blood mononuclear cells before and after cardiopulmonary bypass were analyzed for the expression of immunomodulatory cell markers by real-time quantitative reverse transcription polymerase chain reaction. T cell effector functions were determined by enzyme-linked immunosorbent assay, carboxyfluorescein succinimidyl ester staining, and cytotoxicity assays. Expression of cell surface markers was assessed by flow cytometry. CD15 cells were depleted by microbead separation. Serum arginine was measured by mass spectrometry. Patient peripheral blood mononuclear cells were incubated in different arginine concentrations, and T cell functions were tested. Measurements and main results After cardiopulmonary bypass, peripheral blood mononuclear cells exhibited significantly reduced levels of costimulatory receptors (inducible T-cell costimulator, interleukin 7 receptor), whereas inhibitory receptors (programmed cell death protein 1 and programmed cell death 1 ligand 1) were induced. T cell effector functions (interferon γ secretion, proliferation, and CD8-specific cell lysis) were markedly repressed. In 66 of 71 patients, a not yet described cell population was found, which could be characterized as myeloid-derived suppressor cells. Myeloid-derived suppressor cells are known to impair immune cell functions by expression of the arginine-degrading enzyme arginase-1. Accordingly, we found dramatically increased arginase-1 levels in post-cardiopulmonary bypass peripheral blood mononuclear cells, whereas serum arginine levels were significantly reduced. Depletion of myeloid-derived suppressor cells from post-cardiopulmonary bypass peripheral blood mononuclear cells remarkably improved T cell effector function in vitro. Additionally, in vitro supplementation of arginine enhanced T cell immunocompetence. Conclusions Cardiopulmonary bypass strongly impairs the adaptive immune system by triggering the accumulation of myeloid-derived suppressor cells. These myeloid-derived suppressor cells induce an immunosuppressive T cell phenotype by increasing serum arginine breakdown. Supplementation with L-arginine may be an effective measure to counteract the onset of immunoparalysis in the setting of cardiopulmonary bypass.

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.

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.

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

Purpose To evaluate the role of plasma disappearance rate of indocyanine green (PDR-ICG) as an outcome prediction tool in cardiac surgery. Patients and Methods One hundred ninety patients undergoing coronary artery bypass grafting, valve surgery or combined procedures were enrolled. PDR-ICG measurements along with standard lab values were performed preoperative and on postoperative days 1, 2, and on discharge from the intensive care unit. Adverse outcomes were defined as prolonged length of stay in the intensive care unit and/or mortality. Two groups were defined according to length of stay in the intensive care unit (≤ 3 days vs > 3 days). Results PDR-ICG values differed significantly for all time points between the groups. In a multivariate model, in patients over 65 years with a EuroSCORE below 8.5, a preoperative PDR-ICG value below 12.85%/min was the strongest independent predictor for prolonged intensive care unit stay (> 3 days). A preoperative PDR-ICG value below 8.2%/min was the strongest independent predictor for mortality in a multivariate analysis including age, cardiac function, and EuroSCORE. Conclusions In addition to the established scores, PDR-ICG may provide valuable information for the assessment of perioperative morbidity and mortality in cardiac surgery. Pre- and early postoperative measurements may help to identify patients at risk for developing perioperative complications.

Background Thromboembolism is a major complication in patients with ventricular assist devices (VADs). Drug anticoagulation and the use of biocompatible surfaces, such as coating with heparin, aim to reduce thromboembolism in these patients. Administration of heparin can lead to heparin-induced thrombocytopenia (HIT) type II, mainly through heparin/platelet factor 4 (PF4) antibodies. We assessed the presence of PF4 antibodies in VAD thrombi of patients with heparin-coated VADs and HIT II. Methods Thrombi (n = 6) were obtained from the replaced Excor ventricles of patients with HIT II after biventricular VAD implantation (Excor Adult; Berlin Heart, Germany). Excor ventricles were changed after clinical examination and suspicion of thrombi in the polyurethane valves. Expression of PF4- antibodies was assessed with the use of a polyclonal rabbit antibody (anti-PF4 antibody; Abcam, USA). Expression was assessed by 2 independent observers. Results Biopsies of all thrombi showed an extreme positive immunoreaction for PF4. No differences between the different thrombi and localization (left/right Excor ventricle) were observed. The thrombi were organized, without lamination of fibrin and cellular layers. Conclusions Platelet surface expression of PF4 in the thrombi reflects HIT antigen presentation. The physical relationship between the PF4-positive thrombi and the heparin-coated surface suggests that onset of HIT II could be influenced by the immobilized heparin coating.

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.

Peri-operative acute renal failure requiring renal replacement therapy is common (5-30%) after cardiac surgery and associated with a mortality of approximately 50%. Pre-operative renal impairment seems to be the most important risk factor for frank postoperative renal failure. To help evaluate the risk factors, we conducted a prospective observational trial of 1574 consecutive patients with normal pre-operative renal function (creatinine110 micromol.l(-1)). Renal failure was defined as the need for renal replacement therapy. After univariate analysis of previously described risk factors, those who differed significantly between patients with or without renal failure were enrolled into a multivariate classification and regression tree (CART) statistical model that identifies the most 'predictive' risk factors and creates a ranked list of these. In patients with pre-operatively normal renal function, a serum level of lactate1.1 mmol.l(-1) in the first 24 h after the operation was the strongest predictor for the development of renal failure.

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. Single-center clinical study with a historical control group at an university hospital. Forty cardiac bypass surgery patients were included prospectively and compared with a control group. 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. 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 ± 0.27 mg) were administered. They received more colloids (6918 ± 242 vs. 5514 ± 171 ml). 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 ± 17 h) was shorter in the GDT group. 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.

The efficacy of the Trendelenburg position, a common first step to treat suspected hypovolaemia, remains controversial. We evaluated its haemodynamic effects on cardiac preload and performance in patients after cardiac surgery.Twelve patients undergoing mechanical ventilation of the lungs who demonstrated left ventricular 'kissing papillary muscles' by transoesophageal echocardiography, thus suggesting hypovolaemia, were positioned 30 degrees head down for 15 min immediately after cardiac surgery. Cardiac output by thermodilution, central venous pressure, pulmonary artery occlusion pressure, left ventricular end-diastolic area by transoesophageal echocardiography and intrathoracic blood volume by thermo- and dye dilution were determined before, during and after this Trendelenburg manoeuvre.Trendelenburg's manoeuvre was associated with increases in central venous pressure (9 +/- 2 to 12 +/- 3 mmHg) and pulmonary artery occlusion pressure (8 +/- 2 to 11 +/- 3 mmHg). The intrathoracic blood volume index increased slightly (dye dilution from 836 +/- 129 to 872 +/- 112 mL m(-2); thermodilution from 823 +/- 129 to 850 +/- 131 mL m(-2)) as did the left ventricular end-diastolic area index (7.5 +/- 2.1 to 8.1 +/- 1.7 cm2 m(-2)), whereas mean arterial pressure and the cardiac index did not change significantly. After supine repositioning, the cardiac index decreased significantly below baseline (3.0 +/- 0.6 versus 3.5 +/- 0.8 L min(-1) m(-2)) as did mean arterial pressure (76 +/- 12 versus 85 +/- 11 mmHg), central venous pressure (8 +/- 2 mmHg) and pulmonary artery occlusion pressure (6 +/- 4 mmHg). The intrathoracic blood volume index and left ventricular end-diastolic area index did not differ significantly from baseline.Trendelenburg's manoeuvre caused only a slight increase of preload volume, despite marked increases in cardiac-filling pressures, without significantly improving cardiac performance.

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.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.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 P0.01). When the chest was open, similar significant correlations of SVV (P0.001) and PPV (P0.01) were found with GEDVI.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.

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.Prospective study.University hospital.Fifteen mechanically ventilated patients with a left ventricular ejection fraction0.35 (study group) and 15 patients with an ejection fraction0.50 (control group) after coronary artery bypass grafting following admission to the intensive care unit.Volume loading with 10 mL of hetastarch 6% times body mass index. If stroke volume index increased5%, successive volume loading was performed until no further increase in stroke volume index was reached.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.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.

Real-time measurement of stroke volume variation by arterial pulse contour analysis (SVV) is useful in predicting volume responsiveness and monitoring volume therapy in mechanically ventilated patients. This study investigated the influence of the depth of tidal volume (V(t)) on SVV both during the state of fluid responsiveness and after fluid loading in mechanically ventilated patients.Prospective study in a university hospital, adult cardiac surgery intensive care unit.20 hemodynamically stable patients immediately after cardiac surgery.Stepwise fluid loading using colloids until stroke volume index (SVI) did not increase by more than 10%. Before and after fluid loading V(t) was varied (5, 10, and 15 ml/kg body weight) in random order.Pulse contour SVV was measured before and after volume loading at the respective V(t) values. Thirteen patients responded to fluid loading with an increase in SVI greater than 10%, which confirmed volume responsiveness at baseline measurements. These were included in further analysis. During volume responsiveness SVV at V(t) of 5 ml/kg (7+/-0.7%) and SVV at V(t) of 15 ml/kg (21+/-2.5%) differed significantly from that at V(t) of 10 ml/kg (15+/-2.1%). SVV was correlated significantly with the magnitude of V(t). After volume resuscitation SVV at the respective V(t) was significantly reduced; further, SVV at V(t) of 5 ml/kg(-1) (5.3+/-0.6%) and 15 ml/kg (16.2+/-2.0%) differed significantly from that at V(t) of 10 ml/kg (10.2+/-1.0%). SVV and depth of V(t) were significantly related.In addition to intravascular volume status SVV is affected by the depth of tidal volume under mechanical ventilation. This influence must be regarded when using SVV for functional preload monitoring.

Objective: We hypothesized that measuring stroke volume variation (SVV) during mechanical ventilation by continuous arterial pulse contour analysis allows the accurate prediction and monitoring of changes in cardiac index (CI) in response to volume administration. Design and setting: Prospective study in an university hospital. Patients: Twenty mechanically ventilated patients following cardiac surgery. Interventions: Volume loading with oxypolygelatin (3.5%) 20 ml × body mass index over 10 min. Measurements and results: SVV, central venous pressure (CVP), pulmonary artery occlusion pressure (PAOP), left ventricular end-diastolic area index (LVEDAI) by transesophageal echocardiography, intrathoracic blood volume index (ITBVI) by transpulmonary thermodilution and CI were determined immediately before and after volume loading. SVV decreased, while CI, CVP, PAOP, ITBVI, and LVEDAI increased significantly. Percentage changes in CI were significantly correlated to percentage changes in SVV (r2=–0.59, p

To evaluate the performance of two different continuous cardiac output monitoring systems based on the thermodilution principle in critically ill patients.Nineteen cardiac surgical patients were randomly assigned to continuous cardiac output monitoring using one of the two systems under study (group I, IntelliCath(TM) catheter, n=9; group II, Opti-Q(TM) catheter, n=10). Each patient was studied over a period of three hours. Conventional bolus thermodilution cardiac output measurements were carried out every 15 min leading to 13 measurements in each patient. The continuous cardiac output values were compared with the bolus thermodilution measurements. Bias (mean difference between continuous and bolus thermodilution) and precision (SD of differences) were calculated as a measure of agreement between the respective continuous method and conventional bolus thermodilution.The range of measured cardiac outputs was 3.8-15.4 L*min(-1) (IntelliCath(TM)) and 3.5-8.3 L*min(-1) (OptiQ(TM)). Bias and precision was 0.06 +/- 0.76 L*min(-1) (IntelliCath(TM)) and -0.04 +/- 0.74 L*min(-1) (OptiQ(TM)), respectively. There was no difference in bias between the two systems (P=0.38). +/- 2 SD of the differences (i.e., 95% of the differences) did not fall within the predetermined limits of agreement of +/- 0.5 L*min(-1).There was no difference between the two systems regarding the agreement with conventional bolus thermodilution as the standard. A discrepancy between bolus and continuous thermodilution cardiac output measurement techniques above the clinically acceptable limits suggest that they are not interchangeable.

BACKGROUND The present study compared redo coronary artery bypass grafting (Re-OPCAB) techniques with conventional redo coronary artery bypass grafting (Re-CABG) with particular focus on myocardial damage and clinical outcome parameters. METHODS Redo OPCAB (Re-OPCAB) was performed on 20 consecutive patients (15 males, mean age 63.2 +/- 9.3 years) using either the anterolateral approach for minimally invasive direct coronary artery bypass (n = 4) or the Octopus technique with regular sternotomy (n = 16). The Re-CABG group consisted of 20 consecutive patients (18 males, mean age 67.1 +/- 6.6 years). Groups did not differ in the number of atherosclerotic risk factors, or left ventricular, renal or liver function. RESULTS Duration of surgery, number of bypass grafts and amount of transfused red blood cells did not differ significantly between both groups. Requirement of epinephrine (mg/h) within the first 24 h was lower in the Re-OPCAB group (Re-OPCAB: 0.14 +/- 0.22 vs. CABG: 0.88 +/- 0.97; p

Background . The purpose of this study was to evaluate the course of serum markers of myocardial tissue damage after two different types of minimally invasive coronary surgical procedures (MICS) as compared with conventional coronary artery bypass grafting (CABG). Methods . We enrolled 87 patients with one- or two- vessel disease scheduled for one of the three procedures: minimally invasive direct coronary artery bypass grafting (MIDCABG) by lateral thoracotomy (n = 29), the OCTOPUS method by median sternotomy (n = 27), and CABG (n = 31). Creatine kinase activity (CK), creatine kinase MB activity (CK-MB act), creatine kinase MB mass concentration (CK-MB mass), myoglobin concentration (MG), and cardiac troponin I concentration (cTnI) were measured perioperatively until the second postoperative day. Results . Creatine kinase-MB, CK-MB mass, and cTnI were significantly higher after CABG and were nearly maintained within the normal range in MICS. Creatine kinase and MG were significantly lower in the OCTOPUS group than in the MIDCABG or CABG groups. Conclusions . Minimally invasive coronary surgical procedures cause less myocardial injury than CABG as indicated by specific serum markers. However, higher CK and MG reflect more substantial skeletal muscle trauma during MIDCABG operation compared with Octopus procedures.

Objectives: Health-related quality of life and patient satisfaction have become important end points in cardiac surgery. Post-traumatic stress disorder has been described in patients with life-threatening heart disease. In this study, we investigated the occurrence of post-traumatic stress disorder in a sample of patients after cardiac surgery and compared health-related quality of life and patient satisfaction between patients with and without evidence of post-traumatic stress disorder. Methods: We studied 80 patients serially admitted to the intensive care unit after cardiac surgery (bypass grafting, n = 51; aortic valve replacement, n = 29). Health-related quality of life was assessed with the use of the SF-36 Health Status Questionnaire. Post-traumatic stress disorder was measured with a previously validated instrument (the Post-Traumatic Stress Syndrome 10-Questions Inventory), and 20 different aspects of life satisfaction were quantified on a scale ranging from 0 to 10. For measurements of health-related quality of life and post-traumatic stress disorder, age- and gender-comparable healthy individuals, as well as patients with cardiovascular diseases, served as control groups. Results: Patients who had cardiac surgery described high life satisfaction summary scores (156 of a maximum of 200 points) and only small impairments in physical and mental SF-36 summary scores when compared with healthy control groups (median reduction 7.15, P

Objectives: To shorten hospital stay after cardiac surgery, several risk factors have been defined to identify patients who can be discharged early. These risk factors are dependant on the patient; no studies exist on the influence of the treating physician himself on postoperative patient stay. Methods: In a university affiliated cardiac surgical clinic we investigated patients who were postoperatively treated either on medical wards with no cardiac surgeon’s presence or on a cardiac surgical ward; at both types of wards physicians had several years experience with cardiac surgical patients. Taking several risk factors for postoperative morbidity into account, postoperative length of stay and incidence of wound healing complications have been compared. Results: Within a 3-month period, 84 patients were treated at the cardiac surgical ward, 102 patients at the medical wards. Risk factors for postoperative morbidity were present in 87% of patients, statistically independent of postoperative wards. Although demographic data and median ICU-stay of both patient groups was comparable, the median post-ICU stay was 9 days at the surgical and 13 days at the medical wards (P , 0:0001). Incidence of wound healing complication was higher (19.6%) at the medical wards than at the surgical ward (10.7%), without reaching statistical significance. Conclusion: As patients at the respective wards were statistically not different, the difference in post-ICU stay, infection and costs must depend on the treating physicians. As a consequence, postoperative care for cardiac surgical patients in all cases should include direct cardiac surgical participation. q 1999 Elsevier Science B.V. All rights reserved.

To investigate the effects of stress doses of hydrocortisone on the duration of vasopressor therapy in human septic shock.Prospective, randomized, double-blind, single-center study.Twenty-bed multidisciplinary intensive care unit in a 1400-bed university hospital.Forty consecutive patients who met the ACCP/SCCM criteria for septic shock. An additional criterion for inclusion in the study was vasopressor support and high-output circulatory failure with a cardiac index of4 L/min/m2 after fluid resuscitation (pulmonary capillary wedge pressure: 12-15 mm Hg) and without the use of positive inotropes such as dobutamine or dopexamine. The primary study end point was the time to cessation of vasopressor support (norepinephrine or epinephrine in any dose, dopamineor = 6 microg/kg/min). Secondary study end points were the evolution of hemodynamics and the multiple organ dysfunction syndrome (MODS). The severity of illness at recruitment was graded using the Acute Physiology and Chronic Health Evaluation II and the Simplified Acute Physiology Score II scoring systems. MODS was described by the Sepsis-related Organ Failure Assessment score.All eligible patients were prospectively randomized to receive either stress doses of hydrocortisone or placebo. Hydrocortisone was started with a loading dose of 100 mg given within 30 mins and followed by a continuous infusion of 0.18 mg/ kg/hr. When septic shock had been reversed, the dose of hydrocortisone was reduced to 0.08 mg/kg/hr. This dose was kept constant for 6 days. As soon as the underlying infection had been treated successfully or sodium serum concentrations had increased to155 mmol/L, the hydrocortisone infusion was tapered in steps of 24 mg/day. Physiologic saline solution was the placebo.Hemodynamic and oxygen-derived variables were measured at previously defined time points over a study period of 5 days. Relevant clinical and laboratory measurements were registered for a study period of 14 days to assess the evolution of organ dysfunction. Baseline data at recruitment did not differ between the two groups. Shock reversal was achieved in 18 of the 20 patients treated with hydrocortisone vs. 16 of the 20 patients treated with placebo. Hydrocortisone significantly reduced the time to cessation of vasopressor support. The median time of vasopressor support was 2 days (1st and 3rd Quartiles, 1 and 6 days) in the hydrocortisone-treated group and 7 days (1st and 3rd Quartiles, 3 and 19 days) in the placebo group (p = .005 Breslow test). There was a trend to earlier resolution of the organ dysfunction syndrome in the hydrocortisone group.Infusion of stress doses of hydrocortisone reduced the time to cessation of vasopressor therapy in human septic shock. This was associated with a trend to earlier resolution of sepsis-induced organ dysfunctions. Overall shock reversal and mortality were not significantly different between the groups in this low-sized single-center study.

To evaluate the accuracy of a new continuous cardiac output monitor in critically ill patients.Criterion standard study.Cardiac surgery intensive care unit in a university hospital.Twenty cardiac surgical patients requiring intensive care treatment with pulmonary artery catheters after surgery.None.Cardiac output was monitored continuously with a modified pulmonary artery catheter that has a heating filament on the outside of the catheter. Four modes of data processing with different response times ("Normal," "Fast," "FastFilter," and "Urgent" modes) used by the monitoring system. A total of 240 determinations of cardiac output were performed using conventional bolus thermodilution technique; these results were compared with those obtained using three of the four continuous measuring modes available ("Normal," "FastFilter," and "Urgent"). Cardiac output ranged from 3.47 to 15.77 L/min (bolus thermodilution). The mean (bias) +/- SD of differences (precision) for all measurements was 0.40+/-1.26 L/min in the Normal mode (cardiac output10 L/min: 0.34+/-0.66 L/min), 0.53+/-1.27 L/min in the FastFilter-mode (cardiac output10 L/min: 0.60+/-0.75 L/min), and 0.63+/-1.34 L/min in the Urgent mode (cardiac output10 L/min: 0.57+/-0.82 L/min).Continuous cardiac output measurement using the thermodilution technique is reasonably accurate, reliable, and applicable in routine clinical practice. The values obtained using the Normal mode of the monitor agreed significantly better with the conventional thermodilution method than the results of the two other modes studied (FastFilter and Urgent). In addition, measurements in two patients with cardiac output values of10 L/min did not agree with the results of the bolus thermodilution method.

Echocardiography is a noninvasive method for cardiac evaluation. A review of the current literature shows that the routine use of echocardiography for assessing perioperative cardiac risk in patients undergoing noncardiac surgery can not be supported. Only patients with suspected relevant heart valve diseases, acute heart failure, cardiomyopathy or condition after heart or heart-lung transplantation may benefit from preoperative echocardiography. In patients with suspected or proven coronary artery disease stress echocardiography offers the most relevant additional information for the anaesthesiologist. However, because of the high financial and personal implications it should be reserved to those patients who are not able to perform a normal stress test. Besides in patients in whom transthoracic echocardiography doesn't offer sufficient information or is not possible transesophageal echocardiography plays only a minor role in preoperative cardiac evaluation.

Fragestellung: Die transpulmonale Indikatordilutionstechnik (TPID) erlaubt die Bestimmung des Herzzeitvolumens ohne Pulmonalarterienkatheter. Wir untersuchten die Ubereinstimmung der TPID mit der etablierten pulmonalarteriellen Thermodilutionsmessung (PAID). Methodik: Bei 18 Patienten mit akuter respiratorischer Insuffizienz wurden simultan pulmonalarterielle und transpulmonale Herzzeitvolumenmessungen durchgefuhrt (160 Meswertpaare). Auserdem wurde mittels Doppelindikatortechnik (Kalte und Indozyaningrun) das extravaskulare Lungenwasser (EVLW) bestimmt. Ergebnisse: Die mittlere Differenz (±Standardabweichung) zwischen TPID und PAID lag bei 0,03 l/min (±1,04 l/min), die Regressionsanalyse ergab TPID=0,87 PAID+1,16 (r=0,91). Das EVLW war im Mittel mit 1625 ml (Min–Max: 403–3266 ml) in unserem Patientenkollektiv entsprechend der Grundkrankheit deutlich erhoht. Die mittlere Differenz der beiden gemessenen Herzzeitvolumina (PAID-TPID) zeigte keine Abhangigkeit vom EVLW des Patienten. Schlusfolgerungen: Die gute Ubereinstimmung der TPID mit der etablierten pulmonalarteriellen Thermodilutionstechnik uber einen grosen Herzzeitvolumenbereich deutet darauf hin, das ein alternativer Einsatz beider Methoden moglich erscheint. Daruber hinaus konnte erstmals an Patienten gezeigt werden, das die TPID unabhangig vom EVLW des Patienten eine valide Herzzeitvolumenmessung ermoglicht.

Cardiac surgery using cardiopulmonary bypass (CPB) often induces a systemic inflammatory response syndrome (SIRS). The concept of minimally invasive direct coronary artery bypass (MIDCAB) eliminates cardiopulmonary bypass. We evaluated the perioperative time course of procalcitonin (PCT) to compare the inflammatory response due to these two different surgical procedures. 57 patients were studied: CABG with CPB (n = 30), MIDCAB without CPB (n = 27). The following data were measured preoperatively, after induction of anesthesia, after separation from CPB in the CABG group or after left internal mammary artery (LIMA)-to-left anterior descending artery (LAD) anastomosis in MIDCAB group, and every 3 hours for the first 42 hours in the ICU: PCT, C-reactive protein (CRP), body temperature, hemodynamic parameters, and the need for catecholamines. Leucocyte counts were measured daily. For statistical analyses the Friedmann, Wilcoxon, or Mann-Whitney U tests were used. PCT in the CABG group rose to a maximum of 2.0 ng/ml (median) at 15 hrs postoperatively. In the MIDCAB group maximal PCT concentration was 0.7ng/ml (median) (p < 0.05). CRP was elevated to 17.1 mg/dl in the CABG and 18.5mg/dl in the MIDCAB group (n.s.). The leucocyte counts were increased on day 2 in the CABG group (p < 0.05). In the CABG group about 25% of the patients needed noradrenaline, but in the MIDCAB group none (p < 0.05). Body temperature did not differ between both groups. The increase in PCT concentration was more pronounced after CABG, indicating a reduced inflammatory response after MIDCAB. CRP was increased after both procedures. PCT reflects the inflammatory response after cardiac bypass surgery with or without CPB.

Mortality of severe acute respiratory distress syndrome (ARDS) in Germany is about 60%. Respiratory therapy can make the lung injury worse by high positive airway pressures, high tidal volumes and high inspiratory oxygen concentrations. Extracorporeal membrane oxygenation (ECMO) was employed to reduce aggressive mechanical ventilation, but it has not been proved to be superior to conventional ventilation. However, encouraged by recently developed improvements in the technique and concept of ECMO, we introduced this therapy into our program for the treatment of ARDS. PATIENTS AND METHODS. All patients with severe ARDS (lung injury score > 2.5) admitted to our multidisciplinary intensive care unit from March 1992 to March 1995 were evaluated prospectively. After admission, the patients first underwent a conventional therapeutic approach, including pressure-controlled inverse-ratio ventilation, permissive hypercapnia, changes in body position (in particular, the prone position), negative fluid balance, anti-biotics, and low-dose hydrocortisone infusion. ECMO via a covalently heparin-coated, venovenous bypass-system with a vortex pump and two membrane lungs was performed if ARDS did not improve after 24-96 h of conventional therapy and if two of three of the slow-entry criteria for ECMO were fulfilled: (1) PaO2/FiO2 5 mbar; (2) semistatic compliance 30%. Only in cases of life-threatening hypoxemia (PaO2 5 mbar for > 2 h (fast-entry criteria) was ECMO instituted immediately. RESULTS. Sixty patients fulfilled the entry criteria for our study. Thirty-nine patients were treated with a conventional protocol, 37 after improvement of ARDS and 2 who had not improved but in whom there were contraindications to the use of ECMO. ECMO was performed in 10 patients who had not improved, but who fulfilled the slow-entry criteria and in 11 primarily hypoxemic patients who fulfilled the fast-entry criteria. The survival rate was 30/39 (77%) for the conventional therapy group, 6/10 (60%) for the slow-entry group, and 11/11 (100%) for the fast-entry group. The onset of ECMO allowed a significant decrease in peak and mean airway pressures, tidal volume, ventilatory rate, minute volume and inspiratory oxygen concentration. Sufficient gas exchange was provided, and pulmonary artery pressures significantly decreased on bypass. The most frequent complications on bypass were pneumothorax (15/21 patients) and bleeding (7/21 patients). CONCLUSION. In comparison with the historical results at our own institution, the present study demonstrates an improvement in the survival rate from 56% to 78% since ECMO has become available. We conclude that venovenous ECMO with a heparin-bonded bypass circuit is an effective additional option for the treatment of patients with severe ARDS.

The risk factors for systemic fungal infections were analysed retrospectively in 186 orthotopic liver transplant procedures performed in 152 patients between June 1985 and January 1993. The total incidence of systemic fungal infections was 16.5% (25/152). The incidence of disseminated candidiasis, aspergillosis, and combined candidiasis and aspergillosis was 6.5% (n = 10), 7.2% (n = 11) and 2.6% (n = 4), respectively. Mortality associated with systemic fungal infections was 80% (20 of 25 patients). There were ten cases of disseminated candidiasis, with 4 patients surviving, and 11 cases of invasive aspergillosis, with 1 patient surviving. All patients with combined systemic fungal infection died. To identify perioperative risk factors, 39 variables were used to compare patients with systemic fungal infections versus those without fungal infections. Fourteen variables were significantly associated with systemic fungal infections by univariate analysis. A consecutive logistic regression analysis revealed that the amount of fresh frozen plasma transfused due to poor initial function of the allograft and acute renal failure requiring hemofiltration were independently significant risk factors for systemic fungal infections. There was no statistical correlation between systemic fungal infections and the underlying liver disease, previous long-term corticosteroids and the postoperative immunosuppressive therapy. Risk factors identified in this study should be considered in the postoperative care of the individual liver transplant recipient. In our study a poor initial function of the hepatic allograft substantially increased the risk of systemic fungal infection.

Objective: The purpose of this study was to evaluate the reliability and accuracy of a new continuous intra-arterial blood gas monitoring system (IABG; PB3300, Puritan Bennett) over a prolonged period of time ( > 7 days). Design: Prospective criterion standard study. Setting: Anesthesiological intensive care unit in a university hospital. Patients: 11 sensors were tested in 10 mechanically ventilated patients with severe respiratory failure. Interventions: PO2, PCO2, and pH measured using IABG were compared to values obtained from 2 conventional blood gas analyzers. The quality of blood pressure tracings was assessed using a scoring system consisting of 5 grades. Results: The median study period was 205h/sensor (range: 169-506h). 320 blood samples were obtained. The ranges of measured parameters were: PO2=46-433 mmHg, PCO2=25-79 mmHg, pH=7.25-7.55. The mean (SD) differences for the whole study period were: -4.3 (11.9) mmHg for PO2, for the clinically important range (PO2 < 150 mmHg) -1.9 (5.4) mmHg, -2.8 (4.5) mmHg for PCO2, and -0.03 (0.04) for the pH value. The MD (SD) in relation to the sensor lifetime were for days 1-3: -1.1 (5.1) mmHg for PO2, -0.4 (3.9) mmHg for PCO2, and -0.01 (0.03) for the pH value; for days 4-6: -1.5 (6.0) mmHg for PO2, -3.3 (4.0) mmHg for PCO2, and -0.03 (0.03) for the pH value; for days 7-9: -2.5 (4.7) mmHg for PO2, -5.1 (4.6) mmHg for PCO2, and -0.04 (0.04) for the pH value; for days > 9: -4.9 (4.4) mmHg for PO2, -5.3 (4.1) mmHg for PCO2, and -0.05 (0.03) for the pH value. Conclusions: The IABG reliably measured blood gases and pH values with acceptable clinical performance based on the overall results. There was, however, a decline in the agreement of the sensors and conventional values with increasing sensor lifetime. The mean differences (bias) and the standard deviation of differences (precision) of PO2, PCO2 and the pH values were acceptable for clinical purposes up to day 6. The arterial blood pressure tracings and blood withdrawal were not adversely affected. No side effects due to the sensors occurred. In summary, a prolonged sensor use for a period of up to 6 days appears to be reasonable. This system offers on-line information on oxygenation, ventilation, and acid-base status and allows immediate detection of acute and potentially life-threatening events.

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.

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 in a 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 delirium on POD 1 had significantly lower preoperative 2-AG levels of the neuroprotective EC 2-AG (median values, 3.8 vs. 11.3 ng/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% 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.

Continuous monitoring of blood gases and pH could add substantially to patient safety. During the last decade, efforts have been made to develop continuous optochemical blood gas sensors. The initial evaluation of such fibreoptic-based systems showed major patient-interface problems [11]. We evaluated a new intra-arterial blood gas monitoring system (PB3300, Puritan-Bennett, Carlsbad CA) under routine clinical conditions. Methods. After institutional review board approval and with written informed consent, 38 sensors were tested in 25 patients with acute respiratory failure (e.g., the acute respiratory distress syndrome, complications after lung transplantation). Two conventional bench-top blood gas analysers (ABL 520 and ABL 300, Radiometer, Copenhagen) served as criterion standards. The mean differences (bias) and standard deviations (SD) of the differences (precision) were calculated according to the method of Bland and Altman [2]. In addition, linear regression analysis and correlation coefficients were calculated. The quality of blood pressure tracings was assessed using a grading system. Results. The median sensor lifetime was 81.3 h; 869 blood samples (median 14 per sensor) were analysed for the comparison of continuous and conventional blood gas analysis. The ranges for measured parameters were: pH: 6.92 to 7.55; PCO2: 20 to 83 torr; PO2: 31 to 518 torr. The mean differences (SD) were: pH: −0.03 (0.03) or −0.4 (0.4)%; PCO2: −2.6 (4.1) torr or −6.9 (10.9)%; PO2: −3.4 (10.5) torr or −2.9 (7.0)%. The results of linear regression analysis and the correlation coefficients are depicted in Table 2. The mean grade of blood pressure tracings was satisfactory for the clinical setting. Conclusions. The continuous blood gas monitor is sufficiently accurate and precise for clinical use. Bias and precision are better than those known from former studies evaluating fibreoptic blood gas monitors under experimental conditions [7]. Cost-effectiveness was not an issue of this study.

Objective: To evaluate the feasibility and outcomes of protocol-driven noninvasive mechanical ventilation in patients with acute respiratory failure (ARF) after cardiac surgery.Methods: From 2001 to 2004, a total of 2428 cardiac surgery patients admitted to our intensive care unit were observed. After exclusion of patients who received tracheostomy or were discharged while still on mechanical ventilation, 2261 patients with spontaneous breathing were further evaluated for ARF. Patients diagnosed with ARF were treated with intermittent noninvasive mechanical ventilation (NIV) if possible. Risk factors for the development of postoperative ARF as well as outcomes in patients with and without ARF were analyzed.Results: In 2261 spontaneously breathing postoperative cardiac surgical patients after primarily successful extubation, 799 patients (35%) were diagnosed with ARF. Fifty-six patients (7%) did not tolerate NIV treatment. In 743 patients (33%) intermittent NIV was performed. In patients with ARF, ejection fraction was lower, combined cardiac surgical procedures were more frequent, postoperative mechanical ventilation time was longer, and the severity of illness score (SAPS II) was higher (P < .05). The duration of catecholamine support was longer, and the transfusion rate was higher in the NIV group (P < .05); however, mortality did not differ between patients with ARF treated by NIV and patients without ARF.Conclusion: Our study demonstrates the feasibility of NIV in patients after cardiac surgery. These results might suggest that NIV should be considered as first-line ventilatory support in ARF after cardiac surgery. A large randomized trial is warranted to confirm these findings.

We report a 56-year-old male patient developing hypoxemia after surgical replacement of infected valves of a left ventricular assist device (LVAD, Novacor) which had supported him during the previous 15 months. Contrast transesophageal echocardiography (TEE) revealed an atrial septal defect with intermittent right-to-left shunt across a patent foramen ovale. We postulate that the shunt detected in this patient occurred as a consequence of reduced pulmonary vascular compliance due to positive end-expiratory pressure (PEEP) and an increase of mean intrathoracic pressure. Furthermore, we hypothesize that synchronized LVAD operation exacerbates any potential right-to-left shunt due to the profound left ventricular unloading which occurs during LVAD support. In this first report of a right-to-left shunt from a previously unrecognized patent foramen ovale in a Novacor patient, the subsequent transient hypoxemia could be managed by avoiding PEEP of more than 3 mmHg, and mean airway pressure of more than 11 mmHg and by careful volume replacement in order to prevent the pump from completely emptying the left ventricle (LV) and the left atrium (LA). Thus, prior to every LVAD implantation a transesophageal contrast echocardiography with Valsalva maneuver should be performed to identify intracardiac right-to-left shunt.

Severe systemic inflammation (systemic inflammatory response syndrome) associated with cardiac surgery often leads to a worse short-term and long-term outcome. Stress doses of hydrocortisone have been successfully used to improve outcome of CS. The interleukin (IL)-6 to IL-10 ratio is associated with outcome after trauma and major surgery.To evaluate immunologic effects (especially IL-6 to IL-10 ratio) of stress doses of hydrocortisone in a high-risk group of patients after cardiac surgery with cardiopulmonary bypass.Prospective, randomized, double-blinded, placebo-controlled trial.Cardiovascular intensive care unit of a university hospital.High-risk patients (n = 36) undergoing CS.Stress doses of hydrocortisone or placebo.IL-6 to IL-10 ratio and other markers of systemic inflammation at predefined time points; short-term clinical outcome.The two study groups did not differ with regard to demographic data. The patients from the hydrocortisone group (n = 19) had significantly lower levels of IL-6 and higher levels of IL-10, resulting in an attenuated change in IL-6/IL-10 ratio (28.7 [6.4/128.7] vs. 292.8 [6.5/534.6] 4 hours after cardiopulmonary bypass; p0.001). Patients in the hydrocortisone group had a shorter duration of catecholamine support (1 [1/2] vs. 4 [2/4.5] days; p = 0.02), a shorter length of stay in the intensive care unit (2 [2/3] vs. 6 [4/8] days; p = 0.001), and a lower incidence of postoperative atrial fibrillation (26% vs. 59%; p = 0.04).Stress doses of hydrocortisone attenuate the evolution of IL-6/IL-10 ratio in patients with systemic inflammatory response syndrome after CS, which seems to be associated with an improved outcome. The immunologic effects of hydrocortisone may thus be both, inhibitory (IL-6) and permissive (IL-10), regarding the immune response.