Catecholamine and volume therapy for cardiac surgery in Germany--results from a postal survey

[Intensive care treatment of cardiac surgery patients: focus on hemodynamics]

Hemodynamic treatment is a core task in the intensive medical care of cardiac surgery patients. The patient's underlying disease, the type of surgical procedure and the patient's individual characteristics play key roles in the selection of the treatment regimen. The basis of any targeted hemodynamic treatment is the differential diagnosis of the underlying pathological disorder. The established basic monitoring can be expanded if necessary. Postoperative circulatory dysfunction can occur as low cardiac output syndrome (LCOS) predominantly with left or right heart failure or as vasoplegic syndrome (VS). In addition to catecholamines in the narrow sense, various vasoactive and inotropic substances are available for treatment. Knowledge of the recommended target parameters and indication-appropriate monitoring are essential. This article summarizes the current guideline recommendations for the treatment of postoperative circulatory dysfunction.

Comparison of clinical results between transpulmonary thermodilution monitoring and conventional methods in cardiac surgery: An observational study

The Pulse Index Contour Continuous Cardiac Output (PICCO) module provides advanced and continuous monitoring of cardiac output through the use of arterial pulse contour analysis and transpulmonary thermodilution. The objective of this study was to compare the early postoperative outcomes of patients who were monitored using the conventional method and the pulse contour analysis method. A prospective observational study was conducted involving 45 patients who underwent cardiac surgery between 2020 and 2022. Patients were randomly assigned to either Group P (PICCO) or Group C (conventional). In the PICCO cohort, a femoral artery cannula was inserted for the continuous recording and management of hemodynamic data, in accordance with the decision-making algorithm of the module. In the conventional group, cannulation of the radial artery and jugular vein was performed. The postoperative hemodynamic and clinical data are subjected to analysis. The utilization of dopamine was markedly diminished in Group P at both the 0- and 6-hour postoperative intervals, whereas the administration of dobutamine was observed to be elevated (P = .008). The frequency of red packed cell transfusions was higher in Group C at postoperative hour 0. Hemodynamic data indicated a 42% increase in cardiac index and a 33% decrease in systemic vascular resistance, along with a 33% increase in global ejection fraction in patients monitored with PICCO. The mortality rates observed in the 2 groups were not statistically different. The implementation of advanced monitoring techniques, specifically the PICCO module, led to notable enhancements in hemodynamic parameters. The utilization of this technique may prove advantageous in guiding inotrope selection and transfusion decisions during the initial postoperative period. However, it is important to note that morbidity and mortality rates remain comparable.

Impact of vasopressin use for postoperative atrial fibrillation in off-pump coronary artery bypass grafting

Postoperative atrial fibrillation complicates 15-40% of cardiac surgery cases and is associated with various adverse health outcomes including high mortality. Although vasopressin administration decreases postoperative atrial fibrillation in on-pump coronary artery bypass grafting, its use in off-pump coronary artery bypass grafting has not been investigated. Therefore, we evaluated the effect of vasopressin use in off-pump coronary artery bypass grafting. For this retrospective, observational study at a single-center community hospital in Yokkaichi, Japan, 298 patients who had undergone elective or emergency off-pump coronary artery bypass grafting between April 2015 and March 2021 were enrolled. Participants were divided into two groups: vasopressin and non-vasopressin groups. The outcomes in both groups were analyzed after propensity score matching, which revealed 40 patients in each matched group. Patients with chronic atrial fibrillation and those who were converted from off-pump to on-pump surgery were excluded. The primary outcome was postoperative atrial fibrillation occurrence within 4 days post-surgery. Secondary outcomes were 30-day mortality, intensive care unit and hospital stays, and postoperative complications (acute kidney injury, stroke, acute myocardial infarction, and respiratory complications). Although 11 patients (27.5%) in the vasopressin group were affected by postoperative atrial fibrillation when compared to 18 (45%) patients in the non-vasopressin groups, the difference was not significant (P=0.163). Similarly, no significant differences were observed in the secondary outcomes between groups. In off-pump coronary artery bypass grafting, vasopressin use may contribute to reduced postoperative atrial fibrillation; however, a large prospective study needs to be conducted for confirmation.

Vasoplegic Syndrome after Cardiopulmonary Bypass in Cardiovascular Surgery: Pathophysiology and Management in Critical Care

Vasoplegic syndrome (VS) is a common complication following cardiovascular surgery with cardiopulmonary bypass (CPB), and its incidence varies from 5 to 44%. It is defined as a distributive form of shock due to a significant drop in vascular resistance after CPB. Risk factors of VS include heart failure with low ejection fraction, renal failure, pre-operative use of angiotensin-converting enzyme inhibitors, prolonged aortic cross-clamp and left ventricular assist device surgery. The pathophysiology of VS after CPB is multi-factorial. Surgical trauma, exposure to the elements of the CPB circuit and ischemia-reperfusion promote a systemic inflammatory response with the release of cytokines (IL-1β, IL-6, IL-8, and TNF-α) with vasodilating properties, both direct and indirect through the expression of inducible nitric oxide (NO) synthase. The resulting increase in NO production fosters a decrease in vascular resistance and a reduced responsiveness to vasopressor agents. Further mechanisms of vasodilation include the lowering of plasma vasopressin, the desensitization of adrenergic receptors, and the activation of ATP-dependent potassium (KATP) channels. Patients developing VS experience more complications and have increased mortality. Management includes primarily fluid resuscitation and conventional vasopressors (catecholamines and vasopressin), while alternative vasopressors (angiotensin 2, methylene blue, hydroxocobalamin) and anti-inflammatory strategies (corticosteroids) may be used as a rescue therapy in deteriorating patients, albeit with insufficient evidence to provide any strong recommendation. In this review, we present an update of the pathophysiological mechanisms of vasoplegic syndrome complicating CPB and discuss available therapeutic options.

Dopamine use and its consequences in the intensive care unit: a cohort study utilizing the Japanese Intensive care PAtient Database

Background

Dopamine is used to treat patients with shock in intensive care units (ICU) throughout the world, despite recent evidence against its use. The aim of this study was to identify the latest practice of dopamine use in Japan and also to explore the consequences of dopamine use in a large Asian population.

Methods

The Japanese Intensive Care PAtient Database (JIPAD), the largest intensive care database in Japan, was utilized. Inclusion criteria included: 1) age 18 years or older, 2) admitted to the ICU for reasons other than procedures, 3) ICU length of stay of 24 h or more, and 4) treatment with either dopamine or noradrenaline within 24 h of admission. The primary outcome was in-hospital mortality. Multivariable regression analysis was performed, followed by a propensity score-matched analysis.

Results

Of the 132,354 case records, 14,594 records from 56 facilities were included in this analysis. Dopamine was administered to 4,653 patients and noradrenaline to 11,844. There was no statistically significant difference in facility characteristics between frequent dopamine users (N = 28) and infrequent users (N = 28). Patients receiving dopamine had more cardiovascular diagnosis codes (70% vs. 42%; p < 0.01), more post-elective surgery status (60% vs. 31%), and lower APACHE III scores compared to patients given noradrenaline alone (70.7 vs. 83.0; p < 0.01). Multivariable analysis showed an odds ratio for in-hospital mortality of 0.86 [95% CI: 0.71–1.04] in the dopamine ≤ 5 μg/kg/min group, 1.46 [95% CI: 1.18–1.82] in the 5–15 μg/kg/min group, and 3.30 [95% CI: 1.19–9.19] in the > 15 μg/kg/min group. In a 1:1 propensity score matching for dopamine use as a vasopressor (570 pairs), both in-hospital mortality and ICU mortality were significantly higher in the dopamine group compared to no dopamine group (22.5% vs. 17.4%, p = 0.038; 13.3% vs. 8.8%, p = 0.018), as well as ICU length of stay (mean 9.3 days vs. 7.4 days, p = 0.004).

Conclusion

Dopamine is still widely used in Japan. The results of this study suggest detrimental effects of dopamine use specifically at a high dose.

Trial registration Retrospectively registered upon approval of the Institutional Review Board and the administration office of JIPAD.

Effect of Volatile Anesthetics on Myocardial Infarction After Coronary Artery Surgery: A Post Hoc Analysis of a Randomized Trial

OBJECTIVE

To investigate the effect of volatile anesthetics on the rates of postoperative myocardial infarction (MI) and cardiac death after coronary artery bypass graft (CABG).

DESIGN

A post hoc analysis of a randomized trial.

SETTING

Cardiac surgical operating rooms.

PARTICIPANTS

Patients undergoing elective, isolated CABG.

INTERVENTIONS

Patients were randomized to receive a volatile anesthetic (desflurane, isoflurane, or sevoflurane) or total intravenous anesthesia (TIVA). The primary outcome was hemodynamically relevant MI (MI requiring high-dose inotropic support or prolonged intensive care unit stay) occurring within 48 hours from surgery. The secondary outcome was 1-year death due to cardiac causes.

MEASUREMENTS AND MAIN RESULTS

A total of 5,400 patients were enrolled between April 2014 and September 2017 (2,709 patients randomized to the volatile anesthetics group and 2,691 to TIVA). The mean age was 62 ± 8.4 years, and the median baseline ejection fraction was 57% (50-67), without differences between the 2 groups. Patients in the volatile group had a lower incidence of MI with hemodynamic complications both in the per-protocol (14 of 2,530 [0.6%] v 27 of 2,501 [1.1%] in the TIVA group; p = 0.038) and as-treated analyses (16 of 2,708 [0.6%] v 29 of 2,617 [1.1%] in the TIVA group; p = 0.039), but not in the intention-to-treat analysis (17 of 2,663 [0.6%] v 28 of 2,667 [1.0%] in the TIVA group; p = 0.10). Overall, deaths due to cardiac causes were lower in the volatile group (23 of 2,685 [0.9%] v 40 of 2,668 [1.5%] than in the TIVA group; p = 0.03).

CONCLUSIONS

An anesthetic regimen, including volatile agents, may be associated with a lower rate of postoperative MI with hemodynamic complication in patients undergoing CABG. Furthermore, it may reduce long-term cardiac mortality.

Vasoplegic syndrome after cardiovascular surgery: A review of pathophysiology and outcome-oriented therapeutic management

BACKGROUND

Vasoplegic syndrome (VPS) is defined as systemic hypotension due to profound vasodilatation and loss of systemic vascular resistance (SVR), despite normal or increased cardiac index, and characterized by inadequate response to standard doses of vasopressors, and increased morbidity and mortality. It occurs in 9%-44% of cardiac surgery patients after cardiopulmonary bypass (CPB). The underlying pathophysiology following CPB consists of resistance to vasopressors (inactivation of Ca²⁺ voltage gated channels) on the one hand and excessive activation of vasodilators (SIRS, iNOS, and low AVP) on the other. Use of angiotensin-converting enzyme inhibitor (ACE-I), calcium channel blockers, amiodarone, heparin, low cardiac reserve (EF < 35%), symptomatic congestive heart failure, and diabetes mellitus are the perioperative risk factors for VPS after cardiac surgery in adults. Till date, there is no consensus about the outcome-oriented therapeutic management of VPS. Vasopressors such as norepinephrine (NE; 0.025-0.2 µg/kg/min) and vasopressin (0.06 U/min or 6 U/h median dose) are the first choice for the treatment. The adjuvant therapy (hydrocortisone, calcium, vitamin C, and thiamine) and rescue therapy (methylene blue [MB] and hydroxocobalamin) are also considered when perfusion goals (meanarterial pressure [MAP] > 60-70 mmHg) are not achieved with nor-epinephrine and/or vasopressin.

AIMS

The aims of this systematic review are to collect all the clinically relevant data to describe the VPS, its potential risk factors, pathophysiology after CPB, and to assess the efficacy, safety, and outcome of the therapeutic management with catecholamine and non-catecholamine vasopressors employed for refractory vasoplegia after cardiac surgery. Also, to elucidate the current and practical approach for management of VPS after cardiac surgery.

MATERIAL AND METHODS

"PubMed," "Google," and "Medline" weresearched, and over 150 recent relevant articles including RCTs, clinical studies, meta-analysis, reviews, case reports, case series and Cochrane data were analyzed for this systematic review. The filter was applied specificallyusing key words like VPS after cardiac surgery, perioperative VPS following CPB, morbidity, and mortality in VPS after cardiac surgery, vasopressors for VPS that improve outcomes, VPS after valve surgery, VPS after CABG surgery, VPS following complex congenital cardiac anomalies corrective surgery, rescue therapy for VPS, adjuvant therapy for VPS, definition of VPS, outcome in VPS after cardiac surgery, etiopathology of VPS following CPB. This review did not require any ethical approval or consent from the patients.

RESULTS

Despite the recent advances in therapy, the mortality remains as high as 30%-50%. NE has been recommended the most frequent used vasopressor for VPS. It restores and maintain the MAP and provides the outcome benefits. Vasopressin rescue therapy is an alternative approach, if catecholamines and fluid infusions fail to improve hemodynamics. It effectively increases vascular tone and lowers CO, and significantly decreases the 30 days mortality. Hence, suggested a first-line vasopressor agent in postcardiac surgery VPS. Terlipressin (1.3μg/kg/h), a longer acting and more specific vasoconstrictor prevents the development of VPS after CPB in patients treated with ACE-I. MB significantly reduces morbidity and mortality of VPS. The Preoperative MB (1%, 2mg/kg/30min, 1h before surgery) administration in high risk (on ACE-I) patients for VPS undergoing CABG surgery, provides 100% protection against VPS, and early of MB significantly reduces operative mortality, and recommended as a rescue therapy for VPS. Hydroxocobalamin (5 g) has been recommended as a rescue agent in VPS refractory to multiple vasopressors. A combination of ascorbic acid (6 g), hydrocortisone (200 mg/day), and thiamine (400 mg/day) as an adjuvant therapy significantly reduces the vasopressors requirement, and provides mortality and morbidity benefits.

CONCLUSION

Currently, the VPS is frequently encountered (9%-40%) in cardiac surgical patients with predisposing patient-specific risk factors and combined with inflammatory response to CPB. Multidrug therapy (NE, MB, AVP, ATII, terlipressin, hydroxocobalamin) targeting multiple receptor systems is recommended in refractory VPS. A combination of high dosage of ascorbic acid, hydrocortisone and thiamine has been used successfully as adjunctive therapyto restore the MAP. We also advocate for the early use of multiagent vasopressors therapy and catecholamine sparing adjunctive agents to restore the systemic perfusion pressure with a goal of preventing the progressive refractory VPS.

Associations between mean systemic filling pressure and acute kidney injury: An observational cohort study following cardiac surgery

BACKGROUND

Venous congestion has been implied in cardiac surgery-associated acute kidney injury (CSA-AKI). The mean systemic filling pressure may provide a physiologically more accurate estimate of renal venous pressure and renal perfusion pressure but its association with CSA-AKI has not been reported.

METHODS

Patients admitted to ICU following cardiac surgery without pre-operative renal dysfunction were included with monitoring of mean arterial pressure (MAP) and central venous pressure (CVP) and cardiac output (CO) to calculate the mean systemic filling pressure analogue (P_msa ). The AKI-KDIGO guidelines were used to define CSA-AKI. Logistic regression models including CO, heart rate, MAP, CVP and P_msa were used to ascertain the association with CSA-AKI and reported by odds ratio (OR) with 95% confidence interval (95%CI) and area under the curve (AUROC).

RESULTS

One hundred and thirty patients (out of 221 screened) were included of whom 66 (51%) developed CSA-AKI. Patients with CSA-AKI were older, with greater weight and increased stay in ICU while the proportion of comorbidities, type of surgical procedures, APACHE III scores and fluid volumes administered were similar to patients without AKI. The P_msa , but not CVP, was associated with CSA-AKI (OR 1.2 95%CI [1.16-1.25]). Renal perfusion pressure was associated with CSA-AKI estimated as MAP-P_msa (OR 0.81 [0.76-0.86]) and MAP-CVP (OR 0.89 [0.85-0.93]) with the former generating a higher AUROC (median difference 0.10 [0.07-0.12], P < .001) in the regression model.

CONCLUSIONS

The P_msa in post-operative cardiac surgery patients was associated with the development of CSA-AKI also when incorporated into estimates of renal perfusion pressure.

Volume status and volume responsiveness in postoperative cardiac surgical patients: An observational, multicentre cohort study

BACKGROUND

The best strategy to identify patients in whom fluid loading increases cardiac output (CO) following cardiac surgery remains debated. This study examined the utility of a calculated mean systemic filling pressure analogue (P_msa ) and derived variables to explain the response to a fluid bolus.

METHODS

The P_msa was calculated using retrospective, observational cohort data in the early postoperative period between admission to the intensive care unit and extubation within 6 hours. The venous return pressure gradient (VRdP) was calculated as P_msa  - central venous pressure. Concurrent changes induced by a fluid bolus in the ratio of the VRdP over P_msa , the volume efficiency (E_vol ), were studied to assess fluid responsiveness. Changes between P_msa and derived variables and CO were analysed by Wilcoxon rank-sum test, hierarchial clustering and multiple linear regression.

RESULTS

Data were analysed for 235 patients who received 489 fluid boluses. The P_msa increased with consecutive fluid boluses (median difference [range] 1.3 [0.5-2.4] mm Hg, P = .03) with a corresponding increase in VRdP (median difference 0.4 [0.2-0.6] mm Hg, P = .04). Hierarchical cluster analysis only identified E_vol and the change in CO within one cluster. The multiple linear regression between P_msa and its derived variables and the change in CO (overall r²  = .48, P < .001) demonstrated the best partial regression between the continuous change in CO and the concurrent E_vol (r = .55, P < .001).

CONCLUSION

The mean systemic filling P_msa enabled a comprehensive interpretation of fluid responsiveness with volume efficiency useful to explain the change in CO as a continuous phenomenon.

Dobutamine-sparing versus dobutamine-to-all strategy in cardiac surgery: a randomized noninferiority trial

Background

The detrimental effects of inotropes are well-known, and in many fields they are only used within a goal-directed therapy approach. Nevertheless, standard management in many centers includes administering inotropes to all patients undergoing cardiac surgery to prevent low cardiac output syndrome and its implications. Randomized evidence in favor of a patient-tailored, inotrope-sparing approach is still lacking. We designed a randomized controlled noninferiority trial in patients undergoing cardiac surgery with normal ejection fraction to assess whether an dobutamine-sparing strategy (in which the use of dobutamine was guided by hemodynamic evidence of low cardiac output associated with signs of inadequate tissue perfusion) was noninferior to an inotrope-to-all strategy (in which all patients received dobutamine).

Results

A total of 160 patients were randomized to the dobutamine-sparing strategy (80 patients) or to the dobutamine-to-all approach (80 patients). The primary composite endpoint of 30-day mortality or occurrence of major cardiovascular complications (arrhythmias, acute myocardial infarction, low cardiac output syndrome and stroke or transient ischemic attack) occurred in 25/80 (31%) patients of the dobutamine-sparing group (p = 0.74) and 27/80 (34%) of the dobutamine-to-all group. There were no significant differences between groups regarding the incidence of acute kidney injury, prolonged mechanical ventilation, intensive care unit or hospital length of stay.

Discussion

Although it is common practice in many centers to administer inotropes to all patients undergoing cardiac surgery, a dobutamine-sparing strategy did not result in an increase of mortality or occurrence of major cardiovascular events when compared to a dobutamine-to-all strategy. Further research is needed to assess if reducing the administration of inotropes can improve outcomes in cardiac surgery.

Trial registration ClinicalTrials.gov, NCT02361801. Registered Feb 2nd, 2015. https://clinicaltrials.gov/ct2/show/NCT02361801

Vasopressor Therapy in Cardiac Surgery-An Experts' Consensus Statement

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

Association between high dose catecholamine support and liver dysfunction following cardiac surgery

BACKGROUND

Cardiac surgery using cardiopulmonary bypass is a well-established procedure. However, up to 20% to 30% of patients require high dose vasopressor or inotropic support following surgery, enhancing the risk of organ dysfunction and impacting mortality. Nonalcoholic fatty liver disease (NAFLD) is a frequent finding in these patients and may be involved in the pathophysiology of vasoplegia and cardiac failure.

METHODS

Retrospective analysis of 463 patients undergoing elective cardiac surgery in 2014 at our institution. NAFLD was defined using the NAFLD fibrosis score and the vasoactive-inotropy score was used to determine postoperative vasopressor and inotropic dependency.

RESULTS

Patients with NAFLD more often presented with high vasopressor or inotropic support compared to patients without NAFLD, resulting in significant differences after 6 hours (n = 20 [27.0%] of 74 patients), 12 hours (n = 20 [27.0%] of 74 patients), and on the first postoperative day (n = 12 [16.4%] of 73 patients) of intensive care unit (ICU) treatment. Multivariate analysis revealed time of catecholamine application (P = .001), preoperative left ventricular ejection fraction (P = .001), type of surgery (P = .001), model of endstage liver disease on hospital admission (P = .002), pre-existing pulmonary hypertension (P = .004) and NAFLD-time interaction (P = .05) as independent predictors of high vasopressor and inotropic support. Patients with NAFLD had higher degrees of extrahepatic organ dysfunction, were more dependent on hemodialysis, spent more days in the ICU and within the hospital. Patients with NAFLD and high catecholamine support had the highest mortality rates among the study population.

CONCLUSIONS

NAFLD is a common finding in elective cardiac surgery patients. Anesthesiologists and intensivists should be sensitive for the specific risk profile of this population.

Hypertonic saline for fluid resuscitation after cardiac surgery (HERACLES): study protocol for a preliminary randomised controlled clinical trial

BACKGROUND

Intraoperative and postoperative management of cardiac surgery patients is complex, involving the application of differential vasopressors and volume therapy. It has been shown that a positive fluid balance has a major impact on postoperative outcome. Today, the advantages and disadvantages of buffered crystalloid solutes are a topic of controversy, with no consensus being reached so far. The use of hypertonic saline (HS) has shown promising results with respect to lower total fluid balance and postoperative weight gain in critically ill patients in preliminary studies. However, collection of more data on HS in critically ill patients seems warranted. This preliminary study aims to investigate whether fluid resuscitation using HS in patients following cardiac surgery results in less total fluid volume being administered.

METHODS

In a prospective double-blind randomised controlled clinical trial, we aim to recruit 96 patients undergoing elective cardiac surgery for ischaemic and/or valvular heart disease. After postoperative admission to the intensive care unit (ICU), patients will be randomly assigned to receive 5 ml/kg ideal body weight HS (7.3% NaCl) or normal saline (NS, 0.9% NaCl) infused within 60 min. Blood and urine samples will be collected preoperatively and postoperatively up to day 6 to assess changes in renal, cardiac, inflammatory, acid-base, and electrolyte parameters. Additionally, we will perform renal ultrasonography studies to assess renal blood flow before, during, and after infusion, and we will measure total body water using preoperative and postoperative body composition analysis (bioimpedance). Patients will be followed up for 90 days.

DISCUSSION

The key objective of this study is to assess the cumulative amount of fluid administered in the intervention (HS) group versus control (NS) group during the ICU stay. In this preliminary, prospective, randomised controlled clinical trial we will test the hypothesis that use of HS results in less total fluids infused and less postoperative weight gain when compared to the standard of intensive care in cardiac surgery patients.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03280745 . Registered on 12 September 2017.

Fluid management in patients undergoing cardiac surgery: effects of an acetate- versus lactate-buffered balanced infusion solution on hemodynamic stability (HEMACETAT)

BACKGROUND

Recent evidence suggests that acetate-buffered infusions result in better hemodynamic stabilization than 0.9% saline in patients undergoing major surgery. The choice of buffer in balanced crystalloid solutions may modify their hemodynamic effects. We therefore compared the inopressor requirements of Ringer's acetate and lactate for perioperative fluid management in patients undergoing cardiac surgery.

METHODS

Using a randomized controlled double-blind design, we compared Ringer's acetate (RA) to Ringer's lactate (RL) with respect to the average rate of inopressor administered until postoperative hemodynamic stabilization was achieved. Secondary outcomes were the cumulative dose of inopressors, the duration of inopressor administration, the total fluid volume administered, and the changes in acid-base homeostasis. Patients undergoing elective valvular cardiac surgery were included. Patients with severe cardiac, renal, or liver disease were excluded from the study.

RESULTS

Seventy-five patients were randomly allocated to the RA arm, 73 to the RL. The hemodynamic profiles were comparable between the groups. The groups did not differ with respect to the average rate of inopressors (RA 2.1 mcg/kg/h, IQR 0.5-8.1 vs. RL 1.7 mcg/kg/h, IQR 0.7-8.2, p = 0.989). Cumulative doses of inopressors and time on individual and combined inopressors did not differ between the groups. No differences were found in acid-base parameters and their evolution over time.

CONCLUSION

In this study, hemodynamic profiles of patients receiving Ringer's lactate and Ringer's acetate were comparable, and the evolution of acid-base parameters was similar. These study findings should be evaluated in larger, multi-center studies.

TRIAL REGISTRATION

Clinicaltrials.gov NCT02895659 . Registered 16 September 2016.

Intraoperative reduction of vasopressors using processed electroencephalographic monitoring in patients undergoing elective cardiac surgery: a randomized clinical trial

Intraoperative vasopressor and fluid application are common strategies against hypotension. Use of processed electroencephalographic monitoring (pEEG) may reduce vasopressor application, a known risk factor for organ dysfunction, in elective cardiac surgery patients. Randomized single-centre clinical trial at Jena University Hospital. Adult patients operated on cardiopulmonary bypass or off-pump coronary artery bypass grafting were randomised to receive anesthesia with visible or blinded pEEG using Narcotrend™. In blinded-Narcotrend (NT) depth of anesthesia was extrapolated from clinical signs, hemodynamic response and anesthetic concentration, supplemented by target indices between 37 and 64 in the visible-NT group. Intraoperative norepinephrine requirement (primary endpoint), fluid balance, extubation time, delirium occurrence and adverse events were evaluated. Patients of the intent-to-treat population (visible-NT: n = 123, blinded-NT: n = 122) had similar patient and procedural characteristics. Adjusted for type of surgery intraoperative Norepinephrine application was significantly reduced in visible-NT (n = 120, robust mean of cumulative dose 4.71 µg/kg bodyweight) compared to blinded-NT patients (n = 119, 6.14 µg/kg bodyweight) (adjusted robust mean difference 1.71 (95% CI 0.33-3.10) µg/kg bodyweight). Although reduction in patients operated on cardiopulmonary bypass was higher the interaction was not significant in post-hoc subgroup analysis. Intraoperative fluid balance was similar among both groups and strata. Extubation time was non-significantly lower in visible than in blinded-NT group. Overall postoperative delirium risk was 16.4% without differences among the groups. Adverse events-sudden movement/coughing, perspiration or hypertension-occurred more often with visible-NT, while one blinded-NT patient experienced intraoperative awareness. Titration of depth of anesthesia in elective cardiac surgery patients using pEEG allows to reduce application of norepinephrine.

Crystalloid fluid choice in the critically ill : Current knowledge and critical appraisal

Intravenous infusion of crystalloid solutions is one of the most frequently administered medications worldwide. Available crystalloid infusion solutions have a variety of compositions and have a major impact on body systems; however, administration of crystalloid fluids currently follows a "one fluid for all" approach than a patient-centered fluid prescription. Normal saline is associated with hyperchloremic metabolic acidosis, increased rates of acute kidney injury, increased hemodynamic instability and potentially mortality. Regarding balanced infusates, evidence remains less clear since most studies compared normal saline to buffered infusion solutes.; however, buffered solutes are not homogeneous. The term "buffered solutes" only refers to the concept of acid-buffering in infusion fluids but this does not necessarily imply that the solutes have similar physiological impacts. The currently available data indicate that balanced infusates might have some advantages; however, evidence still is inconclusive. Taking the available evidence together, there is no single fluid that is superior for all patients and settings, because all currently available infusates have distinct differences, advantages and disadvantages; therefore, it seems inevitable to abandon the "one fluid for all" strategy towards a more differentiated and patient-centered approach to fluid therapy in the critically ill.

Postoperative Critical Care of the Adult Cardiac Surgical Patient. Part I: Routine Postoperative Care

OBJECTIVES

Cardiac surgery, including coronary artery bypass, cardiac valve, and aortic procedures, is among the most common surgical procedures performed in the United States. Successful outcomes after cardiac surgery depend on optimum postoperative critical care. The cardiac intensivist must have a comprehensive understanding of cardiopulmonary physiology and the sequelae of cardiopulmonary bypass. In this concise review, targeted at intensivists and surgeons, we discuss the routine management of the postoperative cardiac surgical patient.

DATA SOURCE AND SYNTHESIS

Narrative review of relevant English-language peer-reviewed medical literature.

CONCLUSIONS

Critical care of the cardiac surgical patient is a complex and dynamic endeavor. Adequate fluid resuscitation, appropriate inotropic support, attention to rewarming, and ventilator management are key components. Patient safety is enhanced by experienced personnel, a structured handover between the operating room and ICU teams, and appropriate transfusion strategies.

Clinical practice in perioperative monitoring in adult cardiac surgery: is there a standard of care? Results from an national survey

This study was to investigate and define what is considered as a current clinical practice in hemodynamic monitoring and vasoactive medication use after cardiac surgery in Italy. A 33-item questionnaire was sent to all intensive care units (ICUs) admitting patients after cardiac surgery. 71 out of 92 identified centers (77.2 %) returned a completed questionnaire. Electrocardiogram, invasive blood pressure, central venous pressure, pulse oximetry, diuresis, body temperature and blood gas analysis were identified as routinely used hemodynamic monitoring, whereas advanced monitoring was performed with pulmonary artery catheter or echocardiography. Crystalloids were the fluids of choice for volume replacement (86.8 % of Centers). To guide volume management, central venous pressure (26.7 %) and invasive blood pressure (19.7 %) were the most frequently used parameters. Dobutamine was the first choice for treatment of left heart dysfunction (40 %) and epinephrine was the first choice for right heart dysfunction (26.8 %). Half of the Centers had an internal protocol for vasoactive drugs administration. Intra-aortic balloon pump and extra-corporeal membrane oxygenation were widely available among Cardiothoracic ICUs. Angiotensin-converting enzyme inhibitors were suspended in 28 % of the Centers. The survey shows what is considered as standard monitoring in Italian Cardiac ICUs. Standard, routinely used monitoring consists of ECG, SpO2, etCO2, invasive BP, CVP, diuresis, body temperature, and BGA. It also shows that there is large variability among the various Centers regarding hemodynamic monitoring of fluid therapy and inotropes administration. Further research is required to better standardize and define the indicators to improve the standards of intensive care after cardiac surgery among Italian cardiac ICUs.