Blood pressure control with phenylephrine or dobutamine: a randomized controlled trial comparing effects on cerebral and paravertebral tissue oxygen saturation measured with near-infrared spectroscopy.

Preserving haemodynamics is expected to positively affect tissue oxygen saturation. We hypothesized that maintaining mean arterial blood pressure (MAP) (using phenylephrine (PE) or dobutamine (Dobu)) would equally affect regional cerebral and paravertebral tissue saturation (rScO2 and rSpvO2, respectively). Thirty-four patients were randomly assigned to receive either PE or Dobu, in order to keep MAP within 20% of the preoperative value. Their effect on haemodynamics, rScO2 and rSpvO2 at thoracic level T3-T4, T9-T10 and lumbar level L1-L2 was calculated at different doses. Drug-induced haemodynamic effects differed between groups (∆MAP: -2%±21 and - 19%±17, ∆CI: -14.6%±14.6 and 24.1%±49.9, ∆HR: -21%±21 and 0%±16 for PE and Dobu, respectively). Both groups exhibited a significant decrease in rScO2, with a more pronounced decline in the PE group (-14.1%±16.1) compared to the Dobu group (-5.9%±10.6). There were no significant changes at the paravertebral level in either group, but a slight but statistically significant difference was detected between the two groups at T3-T4 and L1-L2. Current guidelines advocate maintaining adequate systemic blood pressures to prevent spinal cord ischaemia in specific procedures. However, it is still unknown which circulatory supportive drug is more beneficial for maintaining spinal cord perfusion. Our data indicates that, when used for maintenance of blood pressure within a 20% range of preoperative values, neither phenylephrine nor dobutamine affect paravertebral tissue saturation.

Incongruous effect of phenylephrine on changes in cerebral blood volume measured by near-infrared spectroscopy (NIRS) indicating extracranial contamination.

We assessed extracranial contamination of the near-infrared spectroscopy (NIRS) signal during administration of phenylephrine. The study was performed with NIRO 200NX which employs both the Modified Beer-Lambert (MBL) method to measure total hemoglobin (tHb, expressed in µM), and Spatially Resolved Spectroscopy (SRS) to measure total hemoglobin content (nTHI, expressed in arbitrary units (a.u.)). SRS tends to not be affected by extracranial blood flow. As vasoconstriction with phenylephrine mainly occurs in the extracranial area, we hypothesized that if NIRS measurements are indeed prone to extracranial contamination, tHb will be more affected by the administration of phenylephrine than nTHI. After ethical committee approval, 20 consenting cardiac surgery patients were included. Phenylephrine was administered whenever clinically indicated and its effect on nTHI and tHb was evaluated. To adjust for the difference in raw scale units, Z-scores were calculated. Data were analyzed with Wilcoxon Signed Ranks Test and the Hodges-Lehmann method. A total of 191 data sets were obtained in 20 patients (10 male, 65 ± 15 years, 77 ± 16 kg, 166 ± 11 cm). The median difference before and after administration of phenylephrine was - 0.006 a.u. [95%CI - 0.010 to - 0.002] (p < 0.001) and - 0.415 µM [95%CI - 0.665 to - 0.205] (p < 0.001) for nTHI and tHb, respectively. The median difference between the Z-scores of nTHI and tHb was - 0.02 [95%CI - 0.04 to - 0.003] (p = 0.03), with a higher variability in the Z-scores of tHb. Phenylephrine induced significant larger changes in MBL values compared to SRS values, indicating that the MBL method might be more prone to extracranial contamination. Trial and clinical registry: Trial registration number: B670201939459, ethical committee number: 2019/0265, date of approval: March 19, 2019.

Cardiac Biomarkers for the Prediction and Detection of Adverse Cardiac Events After Noncardiac Surgery: A Narrative Review.

Yearly, more than 200 million people worldwide undergo noncardiac surgery, of whom about 5% will develop cardiovascular complications. Prevention, early recognition, and prompt treatment of these adverse cardiovascular events is therefore an important concern in perioperative medicine. The present narrative review aims to provide an overview and critical analysis of the currently available evidence on the role of biomarkers in perioperative cardiac risk assessment and monitoring of perioperative cardiac events before and after noncardiac surgery.

Ephedrine and phenylephrine induce opposite changes in cerebral and paraspinal tissue oxygen saturation, measured with near-infrared spectroscopy: a randomized controlled trial.

While the effects of phenylephrine (PE) and ephedrine (E) on cerebral oxygen saturation (rScO2) already has been studied, the effect on paraspinal oxygen saturation (rSpsO2) is still unexplored. This study aims to assess the effect of PE and E on rScO2 and rSpsO2, measured with near-infrared spectroscopy. A randomized 4-treatment cross-over trial was designed in 28 patients under BIS-titrated anaesthesia with sevoflurane. If MAP decreased more than 20% from baseline, incremental doses of PE and/or E were given according to the randomization (group I: E-PE-E, group II: PE-E-PE, group III: E-E-E, group IV: PE-PE-PE). rScO2 and rSpsO2 on T3-T4, T9-T10 and L1-L2 were recorded. Differences in rSO2 (post-pretreatment) within each group were analyzed with paired Student's t test. Differences in effects of PE and E on rScO2 and rSpsO2 were analyzed with linear mixed-modelling. Following PE administration, rScO2 decreased significantly (- 2.7% ± 3.5), while it remained stable following E (- 0.6% ± 3.6). Contrastingly, rSpsO2 at T3-T4, T9-T10 and L1-L2 slightly increased following PE (0.4% ± 2.5, 0.7% ± 2.0 and - 0.1% ± 1.4, respectively), while it decreased after E administration (- 1.3% ± 3.4%, - 0.7% ± 2.6% and - 1.3% ± 2.7%, respectively). Compared to E, PE administration was associated with a significant decrease in rScO2 (- 2.1%, 95% CI [- 3.1%, - 1.2%], p < 0.001). In contrast, compared to PE, E was associated with a significant decrease in rSpsO2 at T3-T4, T9-T10 and L1-L2 (- 2.0%, 95% CI [- 2.8, - 1.1], p < 0.001; - 1.4%, 95% CI [- 2.4%, - 0.4%], p = 0.006; and - 1.5%, 95% CI [- 2.3%, - 0.8%], p < 0.001, respectively). An opposite effect on rScO2 and rSpsO2 was observed after bolus administration of PE and E.

Microvascular reactivity monitored with near-infrared spectroscopy is impaired after induction of anaesthesia in cardiac surgery patients: An observational study.

BACKGROUND: Induction of anaesthesia causes significant macrohaemodynamic changes, but little is known about its effects on the microcirculation. However, alterations in microvascular perfusion are known to be associated with impaired tissue oxygenation and organ dysfunction. Microvascular reactivity can be assessed with vascular occlusion testing, which evaluates the response of tissue oxygen saturation to transient ischaemia and reperfusion. OBJECTIVE: The aim of the current study was to evaluate the effects of an opioid-based anaesthesia induction on microvascular reactivity. We hypothesised that despite minimal blood pressure changes, microvascular function would be impaired. DESIGN: Prospective, observational study. SETTING: Single-centre, tertiary university teaching hospital, Belgium. PATIENTS: Thirty-five adult patients scheduled for elective coronary artery bypass grafting surgery. INTERVENTION: Microvascular reactivity was assessed before and 30 min after anaesthesia induction by means of vascular occlusion testing and near-infrared spectroscopy. MAIN OUTCOME MEASURES: Tissue oxygen saturations, desaturation rate, recovery time (time from release of cuff to the maximum value) and rate of recovery were determined. RESULTS: Data are expressed as median (minimum to maximum). Tissue oxygen saturation was higher after induction of anaesthesia [70 (54 to 78) vs. 73 (55 to 94)%, P = 0.015]. Oxygen consumption decreased after induction, appreciable by the higher minimum tissue oxygen saturation [45 (29 to 69) vs. 53 (28 to 81)%, P < 0.001] and the slower desaturation rate [11 (4 to 18) vs. 9 (5 to 16)% min, P < 0.001]. After induction of anaesthesia, recovery times were longer [40 (20 to 120) vs. 48 (24 to 356) s, P = 0.004] and the rate of recovery was lower [114 (12 to 497) vs. 80 (3 to 271)% min, P < 0.001]. CONCLUSION: After induction of anaesthesia, oxygen consumption was decreased. The longer recovery times and slower rates of recovery indicate impaired microvascular reactivity after induction of anaesthesia. TRIAL REGISTRATION: The research project was registered at ClinicalTrials.gov (NCT02034682).

Assessment of Cerebral Autoregulation Patterns with Near-infrared Spectroscopy during Pharmacological-induced Pressure Changes.

BACKGROUND: Previous work has demonstrated paradoxical increases in cerebral oxygen saturation (ScO2) as blood pressure decreases and paradoxical decreases in ScO2 as blood pressure increases. It has been suggested that these paradoxical responses indicate a functional cerebral autoregulation mechanism. Accordingly, the authors hypothesized that if this suggestion is correct, paradoxical responses will occur exclusively in patients with intact cerebral autoregulation. METHODS: Thirty-four patients undergoing elective cardiac surgery were included. Cerebral autoregulation was assessed with the near-infrared spectroscopy-derived cerebral oximetry index (COx), computed by calculating the Spearman correlation coefficient between mean arterial pressure and ScO2. COx less than 0.30 was previously defined as functional autoregulation. During cardiopulmonary bypass, 20% change in blood pressure was accomplished with the use of nitroprusside for decreasing pressure and phenylephrine for increasing pressure. Effects on COx were assessed. Data were analyzed using two-way ANOVA, Kruskal-Wallis test, and Wilcoxon and Mann-Whitney U test. RESULTS: Sixty-five percent of patients had a baseline COx less than 0.30, indicating functional baseline autoregulation. In 50% of these patients (n = 10), COx became highly negative after vasoactive drug administration (from -0.04 [-0.25 to 0.16] to -0.63 [-0.83 to -0.26] after administration of phenylephrine, and from -0.05 [-0.19 to 0.17] to -0.55 [-0.94 to -0.35] after administration of nitroprusside). A negative COx implies a decrease in ScO2 with increase in pressure and, conversely, an increase in ScO2 with decrease in pressure. CONCLUSIONS: In this study, paradoxical changes in ScO2 after pharmacological-induced pressure changes occurred exclusively in patients with intact cerebral autoregulation, corroborating the hypothesis that these paradoxical responses might be attributable to a functional cerebral autoregulation.

A pathophysiological approach towards right ventricular function and failure.

The scope of this review is to provide a pathophysiological summary of perioperative right ventricular function and failure. In recent decades, the importance of right ventricular function in the perioperative period has been established. However, much of our current knowledge on the management of this clinical entity is based on extrapolation of results from left ventricular research, although biventricular physiology is known to be markedly different in many aspects. Here, on the basis of a thorough literature search, we review theoretical as well as practical aspects of perioperative right ventricular failure. After underlining the importance of this topic, we review basic right ventricular anatomy and physiology, with an emphasis on the role of ventricular interaction. Next, potential causes of perioperative right ventricular failure are discussed. The emphasis of this review is on the perioperative anaesthetic considerations, ranging from preoperative assessment through intraoperative monitoring to specific contemporary therapeutic options of perioperative right ventricular failure.

Implementation of a structured information transfer checklist improves postoperative data transfer after congenital cardiac surgery.

BACKGROUND: During one hospital stay, a patient can be cared for by five different units. With patient transfer from one unit to another, it is of prime importance to convey a complete picture of the patient's situation to minimise the risk of medical errors and to provide optimal patient care. OBJECTIVE(S): This study was designed to test the hypothesis that the implementation of a standardised checklist used during verbal patient handover could improve postoperative data transfer after congenital cardiac surgery. DESIGN: Prospective, pre/postinterventional clinical study. SETTING: Cardiac centre of a university hospital. PATIENTS: Forty-eight patients younger than 16 years undergoing heart surgery. INTERVENTIONS: A standardised checklist was developed containing all data that, according to the investigators, should be communicated during the handover of a paediatric cardiac surgery patient from the operating room to the ICU. MAIN OUTCOME MEASURES: Data transfer during the postoperative handover before and after implementation of the checklist was evaluated. Duration of handover, number of interruptions, number of irrelevant data and number of confusing pieces of information were noted. Assessment of the handover process by ICU medical and nursing staff was quantified. RESULTS: After implementation of the information transfer checklist, the overall data transfer increased from 48 to 73% (P < 0.001). The duration of data transfer decreased from a median (range) of 6 (2 to 16) to 4 min (2 to 19) (P = 0.04). The overall handover assessment by the intensive care nursing staff improved significantly after implementation of the checklist. CONCLUSION: Implementation of an information transfer checklist in postoperative paediatric cardiac surgery patients resulted in a more complete transfer of information, with a decrease in the handover duration.

Cerebral oxygen desaturation during beach chair position.

CONTEXT: Cases of ischaemic brain damage have been reported in relatively healthy patients undergoing shoulder surgery in the beach chair position. Unrecognised cerebral hypoperfusion may have contributed to these catastrophic events, indicating that routine anaesthesia monitoring may not suffice. Near-infrared spectroscopy (NIRS) provides a non-invasive, continuous method to measure regional cerebral oxygen saturation (rScO2). OBJECTIVES: The aim of this clinical investigation was to evaluate the prevalence of regional cerebral oxygen desaturation in patients undergoing shoulder surgery in the upright position during routine anaesthesia management. We also aimed to identify some causal factors for cerebral desaturation. DESIGN: Prospective, observational, blinded study. SETTING: University hospital. Observation period from 19 05 2008 to 26 08 2008. PATIENTS: Twenty consecutive adult patients presenting for elective shoulder surgery under general anaesthesia in the beach chair position were enrolled. Patients with clinically apparent neurological or cognitive dysfunction were excluded. INTERVENTIONS: Routine anaesthesia management and standard monitoring were used. The responsible anaesthesiologist was blinded to the rScO2 data and was not informed about the purpose of the study. MAIN OUTCOME MEASURES: The prevalence of cerebral oxygen desaturation was measured. RESULTS: With beach chair positioning, rScO2 decreased significantly from 79± to 57±9% on the left side and from 77±10 to 59±10% on the right side (P<0.001). A relative decrease in rScO2 of more than 20% occurred in 80% of patients when the beach chair position was adopted. Postural decreases in cerebral oxygenation were related to blood pressure (r=0.60, P=0.007) and end-tidal carbon dioxide concentration (r=0.47, P=0.035). CONCLUSION: The high prevalence of significant cerebral oxygen desaturation during shoulder surgery in the upright position underlines the need for close monitoring. NIRS might constitute a valuable technique to detect cerebral hypoperfusion in this high-risk group of patients.

Magnesium--essentials for anesthesiologists.

Magnesium plays a fundamental role in many cellular functions, and thus there is increasing interest in its role in clinical medicine. Although numerous experimental studies indicate positive effects of magnesium in a variety of disease states, large clinical trials often give conflicting results. However, there is clear evidence for magnesium to benefit patients with eclampsia or torsades de pointes arrhythmias. In addition, magnesium seems to have antinociceptive and anesthetic as well as neuroprotective effects, yet well-designed large clinical trials are required to determine its actual efficacy in pain management or in the state of stroke or subarachnoid hemorrhage. The current review aims to provide an overview of current knowledge and available evidence with respect to physiologic aspects of magnesium and proposed indications and recommendations for its use in the clinical setting.

Effect of remote ischemic conditioning on atrial fibrillation and outcome after coronary artery bypass grafting (RICO-trial).

BACKGROUND: Pre- and postconditioning describe mechanisms whereby short ischemic periods protect an organ against a longer period of ischemia. Interestingly, short ischemic periods of a limb, in itself harmless, may increase the ischemia tolerance of remote organs, e.g. the heart (remote conditioning, RC). Although several studies have shown reduced biomarker release by RC, a reduction of complications and improvement of patient outcome still has to be demonstrated. Atrial fibrillation (AF) is one of the most common complications after coronary artery bypass graft surgery (CABG), affecting 27-46% of patients. It is associated with increased mortality, adverse cardiovascular events, and prolonged in-hospital stay. We hypothesize that remote ischemic pre- and/or post-conditioning reduce the incidence of AF following CABG, and improve patient outcome. METHODS/DESIGN: This study is a randomized, controlled, patient and investigator blinded multicenter trial. Elective CABG patients are randomized to one of the following four groups: 1) control, 2) remote ischemic preconditioning, 3) remote ischemic postconditioning, or 4) remote ischemic pre- and postconditioning. Remote conditioning is applied at the arm by 3 cycles of 5 minutes of ischemia and reperfusion. Primary endpoint is the incidence AF in the first 72 hours after surgery, detected using a Holter-monitor. Secondary endpoints include length-of-stay on the intensive care unit and in-hospital, and the occurrence of major adverse cardiovascular events at 30 days, 3 months and 1 year.Based on an expected incidence in the control group of 27%, 195 patients per group are needed to detect with 80% power a reduction by 45% following either pre- or postconditioning, while allowing for a 10% dropout and at an alpha of 0.05. With the combined intervention expected to be stronger, we need 75 patients in this group to detect a reduction in incidence of AF of 60%. DISCUSSION: The RICO-trial (the effect of Remote Ischemic Conditioning on atrial fibrillation and Outcome) is a randomized controlled multicenter trial, designed to investigate whether remote ischemic pre- and/or post-conditioning of the arm reduce the incidence of AF following CABG surgery. TRIAL REGISTRATION: ClinicalTrials.gov under NCT01107184.

A randomised trial comparing sufentanil versus remifentanil for laparoscopic gastroplasty in the morbidly obese patient.

BACKGROUND AND OBJECTIVE: This prospective, randomised double-blind study compared the effects of target control infusion (TCI) of sufentanil and remifentanil on the quality of recovery and post-operative pain control in morbidly obese patients undergoing laparoscopic gastroplasty. METHODS: Following institutional Ethics Committee approval and written informed consent, 100 morbidly obese patients were randomised to receive either TCI sufentanil (0.3 ng ml⁻¹; S-group; N = 50) or TCI remifentanil (3 ng ml⁻¹; R-group; N = 50) in combination with desflurane (O2/air mixture: FiO2, 50%). Quality of recovery was estimated by means of the modified Aldrete score and by the ability to perform psychomotor tests with the same competence post-operatively as pre-operatively. Post-operative pain was evaluated by the quantity of piritramide needed to achieve a visual analogue scale (VAS) less than 3. Statistical analysis was performed using an unpaired Student's t-test, Mann-Whitney U-test and χ² test, as appropriate. RESULTS: Patient and surgical characteristics were similar among groups. In the R-group, time to extubation was significantly shorter, but VAS significantly higher than that in the S-group (P < 0.01). Quality of recovery and duration of post-anaesthesia care unit stay were comparable between groups (S-group: 119 ± 27 min and R-group: 119 ± 35 min). Piritramide consumption during the first 4 post-operative hours was higher in the R-group than in the S-group [S-group (median, range): 11.5 mg, 5.5-16.0; R-group: 18.0 mg, 14-22, P < 0.01], but not later on. CONCLUSION: In the conditions of the present study, although TCI sufentanil resulted in slower awakening than TCI remifentanil, it was associated with a better quality of recovery.

A randomized controlled trial comparing an intraoperative goal-directed strategy with routine clinical practice in patients undergoing peripheral arterial surgery.

BACKGROUND AND OBJECTIVE: We hypothesized that, in vascular surgery patients, the application of a goal-directed strategy based on a pulse contour-derived cardiac index would be associated with a better haemodynamic status than the application of routine perioperative care and that the amount of fluid and/or inotropes required in such a goal-directed therapy depended on the general anaesthetic technique used. METHODS: Patients undergoing peripheral arterial bypass grafting were randomly assigned to three groups. In group 1, haemodynamic management was performed according to routine clinical practice. In the two other groups (groups 2 and 3) a goal-directed therapy was applied aiming to maintain the pulse contour-derived cardiac index above 2.5 l m min. Patients in groups 1 and 2 received sevoflurane-based anaesthesia and patients in group 3 propofol-based anaesthesia. Haemodynamic variables, amount of fluid and administration of inotropes were assessed at different time intervals. RESULTS: The amount of fluid administered was not significantly different between the groups. Two patients in group 1, 13 patients in group 2 and 12 patients in group 3 were treated with dobutamine (P < 0.001). None of the patients anaesthetized with sevoflurane (groups 1 and 2) experienced postoperative cardiovascular complications, whereas four patients in the total intravenous group (group 3) experienced major postoperative cardiovascular complications (P = 0.005). CONCLUSION: In the conditions of the present study, the application of a goal-directed therapy aiming to maintain the cardiac index above 2.5 l min m did not result in a higher tissue oxygen delivery than when applying the standard haemodynamic strategy nor did it depend on the anaesthetic technique used.

Preoperative cardiovascular assessment in noncardiac surgery: an update.

Cardiac complications are a major cause of perioperative morbidity and mortality. These are caused by either myocardial ischaemia or acute coronary thrombosis. The preoperative assessment aims to collect information on the extent and the stability of the cardiovascular disease in order to predict the patient's risk for developing perioperative cardiac complications. This assessment allows measures to be taken that aim to reduce such risks. The present review summarizes the current state of knowledge on the preoperative assessment of the cardiac patient scheduled for noncardiac surgery.

Drugs mediating myocardial protection.

The occurrence of myocardial ischaemia will result in either reversible or irreversible myocardial dysfunction. Even when revascularization is successful, some reperfusion injury may occur that transiently impairs myocardial function. Therefore, treatment should not only be directed towards prompt restoration of myocardial blood flow but measures should also be taken to prevent or alleviate the consequences of myocardial reperfusion injury. Over the years, various strategies have been developed. The present contribution reviews a number of these strategies focusing on pharmacological treatments that have been developed to address myocardial reperfusion injury.

Update on inhalational anaesthetics.

PURPOSE OF REVIEW: Inhalational anaesthetic agents are a cornerstone in modern anaesthetic practice. The currently used compounds are very effective and have a good safety profile. In addition, it has been demonstrated that they possess organ-protective properties that might provide an additional tool in the treatment or prevention of the consequences of organ ischaemia-reperfusion injury or both. The present review summarizes some of the most recent findings on this subject. RECENT FINDINGS: The mechanisms underlying the organ-protective effects of inhalational anaesthetics continue to be further unravelled. The main challenge, however, is to determine the clinical importance of these protective effects and their potential benefits for patients. Initial observations in cardiac surgery are encouraging, and the first clinical studies on other organ systems are being published. Noble gases share these organ-protective properties and may provide an additional tool for this purpose both in situations in which anaesthesia is needed (xenon) or in cases in which anaesthesia is not necessary (helium). SUMMARY: In the experimental setting, inhalational anaesthetics have protective effects against ischaemia-reperfusion injury. Initial perioperative data suggest that these effects may also result into clinically relevant improved organ function. However, further research will be needed to reveal whether these organ-protective properties will ultimately translate into an improved short-term and long-term postoperative outcome.

Moderate acute isovolemic hemodilution alters myocardial function in patients with coronary artery disease.

BACKGROUND: Although moderate hemodilution is usually well tolerated in coronary artery surgery patients, this may not be the case when myocardial oxygen demand is increased. We hypothesized that, in these patients, hemodilution in the presence of an increased heart rate could be associated with an impairment of myocardial function. METHODS: Forty coronary surgery patients were randomly assigned to two groups (n=20), according to the rate of atrioventricular pacing [70 bpm (Group 70) or 90 bpm (Group 90)]. While paced at the fixed heart rate, hemodilution was performed before the start of cardiopulmonary bypass. Data were obtained from a pulmonary artery, a PiCCO catheter and a left ventricular pressure catheter. Measurements were obtained in steady-state conditions before and after isovolemic hemodilution. RESULTS: Hemodilution from 40%+/-2% to 30%+/-1% in Group 70, and from 39%+/-4% to 30%+/-2% in Group 90 resulted in a decrease in systemic vascular resistance and an increase in end-diastolic volume in both groups. This was associated with an increase in stroke volume in Group 70 but not in Group 90. In this latter group, the maximal rate of pressure development decreased significantly after hemodilution [from 856+/-93 to 716+/-80 mm Hg/s (P<0.01)], whereas it remained unchanged in Group 70 (843+/-86 mm Hg/s before and 832+/-79 mm Hg/s after hemodilution). CONCLUSIONS: In the conditions of the present study, increased heart rate during moderate hemodilution was associated with a depression of myocardial function.

A randomized trial evaluating different modalities of levosimendan administration in cardiac surgery patients with myocardial dysfunction.

OBJECTIVE: To evaluate the effects of 2 different administration modalities of levosimendan (start before cardiopulmonary bypass [CPB] and at the end of CPB) compared with a standard treatment with milrinone started at the end of CPB in cardiac surgery patients with a preoperative ejection fraction <30%. DESIGN: A prospective study. SETTING: A university hospital. PARTICIPANTS: Sixty patients undergoing elective cardiac surgery with CPB. INTERVENTIONS: Patients were randomly assigned to 3 different treatment options for weaning from CPB after cardiac surgery. Group A received milrinone, 0.5 microg/kg/min, after the release of the aortic cross-clamp; group B received levosimendan, 0.1 microg/kg/min, after the induction of anesthesia; and in group C, levosimendan, 0.1 microg/kg/min, was started immediately after the release of the aortic cross-clamp. In all patients, additional dobutamine, 5 microg/kg/min, was initiated after the release of the aortic cross-clamp. Norepinephrine maintained mean arterial pressure constant. MEASUREMENTS AND MAIN RESULTS: Stroke volume after surgery was initially higher than at baseline in all groups and highest in group B. Stroke volume declined 12 hours after surgery in group A but not in groups B and C (p < 0.05 between groups), despite similar filling pressures. Four patients in group A, none in group B, and 1 in group C died within 30 days of surgery. Postoperative atrial fibrillation was observed in 10 patients in group A, 7 patients in group C, and only 1 in group B (p < 0.01). No differences were observed in postoperative troponin I release among groups. CONCLUSION: In the conditions of the present study, starting the levosimendan treatment before CPB was associated with a higher initial postoperative stroke volume and a lower incidence of postoperative atrial fibrillation, but had no effect on the extent of postoperative troponin I release.