Effect of 4% Albumin Solution vs Ringer Acetate on Major Adverse Events in Patients Undergoing Cardiac Surgery With Cardiopulmonary Bypass: A Randomized Clinical Trial

2024 EACTS/EACTAIC/EBCP Guidelines on cardiopulmonary bypass in adult cardiac surgery

Clinical practice guidelines consolidate and evaluate all pertinent evidence on a specific topic available at the time of their formulation. The goal is to assist physicians in determining the most effective management strategies for patients with a particular condition. These guidelines assess the impact on patient outcomes and weigh the risk-benefit ratio of various diagnostic or therapeutic approaches. While not a replacement for textbooks, they provide supplementary information on topics relevant to current clinical practice and become an essential tool to support the decisions made by specialists in daily practice. Nonetheless, it is crucial to understand that these recommendations are intended to guide, not dictate, clinical practice, and should be adapted to each patient's unique needs. Clinical situations vary, presenting a diverse array of variables and circumstances. Thus, the guidelines are meant to inform, not replace, the clinical judgement of healthcare professionals, grounded in their professional knowledge, experience and comprehension of each patient's specific context. Moreover, these guidelines are not considered legally binding; the legal duties of healthcare professionals are defined by prevailing laws and regulations, and adherence to these guidelines does not modify such responsibilities. The European Association for Cardio-Thoracic Surgery (EACTS), the European Association of Cardiothoracic Anaesthesiology and Intensive Care (EACTAIC) and the European Board of Cardiovascular Perfusion (EBCP) constituted a task force of professionals specializing in cardiopulmonary bypass (CPB) management. To ensure transparency and integrity, all task force members involved in the development and review of these guidelines submitted conflict of interest declarations, which were compiled into a single document available on the EACTS website (https://www.eacts.org/resources/clinical-guidelines). Any alterations to these declarations during the development process were promptly reported to the EACTS, EACTAIC and EBCP. Funding for this task force was provided exclusively by the EACTS, EACTAIC and EBCP, without involvement from the healthcare industry or other entities. Following this collaborative endeavour, the governing bodies of EACTS, EACTAIC and EBCP oversaw the formulation, refinement, and endorsement of these extensively revised guidelines. An external panel of experts thoroughly reviewed the initial draft, and their input guided subsequent amendments. After this detailed revision process, the final document was ratified by all task force experts and the leadership of the EACTS, EACTAIC and EBCP, enabling its publication in the European Journal of Cardio-Thoracic Surgery, the British Journal of Anaesthesia and Interdisciplinary CardioVascular and Thoracic Surgery. Endorsed by the EACTS, EACTAIC and EBCP, these guidelines represent the official standpoint on this subject. They demonstrate a dedication to continual enhancement, with routine updates planned to ensure that the guidelines remain current and valuable in the ever-progressing arena of clinical practice.

Perioperative Bleeding Is Not an Independent Risk Factor for Acute Kidney Injury in On-pump Cardiac Surgery-A Post-hoc Analysis of a Randomized Clinical Trial

OBJECTIVES

To study the association between bleeding and acute kidney injury (AKI).

DESIGN

Post-hoc study of a randomized trial of 4% albumin versus Ringer's acetate for cardiopulmonary bypass priming and perioperative volume replacement.

SETTING

Single-center study.

PATIENTS

1,386 on-pump cardiac surgical patients.

MEASUREMENTS AND RESULTS

AKI was defined by the Kidney Disease: Improving Global Outcomes creatinine criteria, and bleeding by the Universal Definition of Perioperative Bleeding (UDPB) classification. With univariably independent factors, two logistic regression analyses (Model 1: AKI Risk Score, EuroSCORE II, and UDPB class; Model 2: risk scores, components of the UDPB classification, and factor VIII/von Willebrand factor concentrate) and a mediation analysis (Model 3: risk scores, UDPB class, and perioperative factors) were performed. A total of 139 (10%) patients developed AKI. In Model 1, UDPB class "severe" (odds ratio: 2.16, 95% confidence interval: 1.19-3.89), "massive" bleeding (6.78, 1.8-25.33), and AKI Risk Score (1.51, 1.29-1.78) were associated with AKI. In Model 2, AKI Risk Score (1.55, 1.33-1.82) and fresh frozen plasma transfusion (1.29, 1.06-1.58) were associated with AKI. In Model 3, the combined UDPB classes "severe" and "massive" bleeding did not have a direct effect (regression coefficient: 0.32, 95% confidence interval: -0.26 to 0.91), while mean arterial pressure (0.08, 0.003-0.21) and fluid balance (0.12, 0.17-0.27) had indirect effects on AKI.

CONCLUSIONS

In on-pump cardiac surgery, perioperative bleeding was not an independent risk factor for AKI but manifested as AKI via hypotension and higher fluid balance. Prevention of bleeding may reduce AKI in cardiac surgery.

Synthetic colloids as priming fluids in cardiopulmonary bypass and postoperative acute kidney injury: a propensity score-matched study

BACKGROUND

The optimal fluid management strategy for patients undergoing on-pump cardiac surgery was controversial regarding the fluid types. This study aimed to compare the impact of hydroxyethyl starch (HES) and succinylated gelatin on postoperative acute kidney injury (AKI).

METHODS

This is a single-center, retrospective study. Adult patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) between 2018 and 2022 were included. Patients were grouped by the priming solution used: HES (the HES group) or succinylated gelatin (the gelatin group). The primary outcome was the incidence of postoperative AKI, and secondary outcomes included continuous renal replacement therapy (CRRT), blood transfusions, myocardial infarction, lung infection, cerebrovascular events, chest drainage, duration of mechanical ventilation, intensive care unit (ICU) stay, in-hospital mortality, and associated costs. Propensity score matching (PSM) was conducted to adjust for characteristic differences between the two groups.

RESULTS

A total of 14,443 patients were included. After 1:1 propensity score matching, 1880 pairs were analyzed. Baseline characteristics were comparable between the matched groups. The incidence of AKI was significantly lower in the gelatin group (3.0% vs. 5.1%, P = 0.001). No significant differences were found in transfusion requirements after score-matching. The use of HES was independently associated with increased odds of AKI (adjusted odds ratio [aOR], 1.785; 95% CI, 1.262-2.526; P = 0.001). The effects of HES use on the occurrence of postoperative AKI were greater in elderly and female patients.

CONCLUSION

The use of HES as a priming solution in on-pump cardiac surgery was associated with an increased risk of postoperative AKI compared to gelatin, although it did not affect transfusion requirements. These findings highlight the importance of considering the priming solution type in fluid management during cardiac surgery.

The Potential Role of Albumin in Reducing Cardiac Surgery-Associated Acute Kidney Injury: A Randomized Controlled Trial

OBJECTIVES

Cardiac surgery-associated acute kidney injury (CSA-AKI) is a common complication with high morbidity and mortality. This study was designed to determine whether adding human albumin to the cardiopulmonary bypass (CPB) priming solution reduces the incidence of CSA-AKI.

DESIGN

A double-blind, randomized controlled trial (RCT) involving 248 patients scheduled for cardiac surgery with CPB.

SETTING

A single-center tertiary university hospital.

PARTICIPANTS

Adults with a baseline estimated glomerular filtration rate (eGFR) of ≥60 mL/min/1.73 m2 and left ventricular ejection fraction ≥40%.

INTERVENTIONS

Patients were randomized to receive either a crystalloid priming solution (Plasma-Lyte) plus 4% albumin (intervention group, n = 126) or a crystalloid solution alone (control group, n = 122) for CPB.

MEASUREMENTS AND MAIN RESULTS

Data analyses were performed using the Chi-square test and Student's t-test, or their nonparametric equivalent. The primary outcome was the incidence of CSA-AKI, as defined by the Kidney Disease Improving Global Outcomes criteria, within 5 days postoperatively. Both cohorts were comparable in baseline and perioperative characteristics, including preoperative albumin levels. The incidence of CSA-AKI was 29.3% (n = 37) in the intervention group compared with 31.2% (n = 38) in the control group (odds ratio: 0.91, 95% confidence interval: 0.53-1.58). The observed difference in CSA-AKI incidence between the groups was not statistically significant. A post-hoc subgroup analysis of patients with a baseline eGFR of 60 to 70 mL/min/1.73 m² indicated a trend toward a reduced incidence of CSA-AKI in the intervention group compared with the control group (35.7% v 57.6%; odds ratio: 0.41, 95% confidence interval: 0.16-1.03). This trend was not observed in patients with an eGFR greater than 70 mL/min/1.73 m². No significant differences were observed between groups for the need for inotropes or vasoconstrictors, incidence of cardiogenic or distributive shock, bleeding, need for transfusion, or use of nephrotoxic drugs.

CONCLUSIONS

Adding albumin to the CPB priming solution did not decrease the incidence of CSA-AKI in patients with normal preoperative renal function. These findings suggest that albumin might benefit patients with impaired renal function, warranting further investigation.

Perioperative Acute Kidney Injury: Diagnosis, Prediction, Prevention, and Treatment

In this review, the authors define acute kidney injury in the perioperative setting, describe the epidemiologic burden, discuss procedure-specific risk factors, detail principles of management, and highlight areas of ongoing controversy and research.

High platelet-to-albumin ratio is associated with 30-day mortality in critically ill patients

BACKGROUND

The role of inflammation and hypoproteinemia in influencing outcomes of critically ill patients has been widely recognized. However, there is a paucity of research on the prognostic value of the platelet-to-albumin ratio (PAR) in critically ill patients. Therefore, the aim of this study is to assess the prognostic significance of PAR in this population.

METHODS

Patients diagnosed with critical illnesses from January 2020 to October 2022 were retrospectively enrolled in our study. Baseline demographic and clinical data were collected for each participant. Platelet counts and albumin levels were measured at baseline, and the PAR was calculated. The area under the receiver operating characteristic curve, Kaplan-Meier survival analysis, and multivariate Cox regression analysis were used to predict 30-day mortality.

RESULTS

Three hundred and seventy-eight patients diagnosed with critical illness were categorized into two groups: survivors (n = 299) and non-survivors (n = 79). Analysis of the 30-day outcome revealed that the area under the curve (AUC) for the PAR (AUC: 0.705; 95% CI 0.639-0.771; p < 0.001) was significantly higher than that for albumin (AUC: 0.673; 95% CI 0.609-0.736; p < 0.001), but slightly lower than that for the APACHE II score (AUC: 0.713; 95% CI 0.650-0.777; p < 0.001). In addition, the Kaplan-Meier survival analysis demonstrated a significantly higher 30-day mortality in the high-PAR group. Furthermore, Cox regression analysis identified albumin (HR: 0.936; 95% CI 0.895-0.978; p = 0.003), APACHE II score (HR: 1.225; 95% CI 1.149-1.305; p < 0.001), and high PAR (HR: 1.237; 95% CI 1.130-1.353; p < 0.001) as independent risk factors for the prognosis of critically ill patients.

CONCLUSIONS

The PAR has emerged as a significant prognostic indicator in critically ill patients, with an elevated ratio being associated with poorer clinical outcomes.

A Randomized Controlled Trial on the Efficacy of 20% Human Albumin in Reducing Pleural Effusion After Cardiopulmonary Bypass

Background/Objectives: Cardiopulmonary bypass can lead to hemodilution, causing a fluid shift to the interstitial space. Albumin helps counteract the intravascular fluid movement to the extravascular space and reduces the risk of complications associated with fluid imbalance. Our main objective was to evaluate the effectiveness of albumin addition in the cardiopulmonary bypass priming solution compared to standard priming, focusing on its role in reducing pleural effusion development. Methods: This was a single-center randomized controlled trial conducted at a tertiary care hospital specializing in cardiology and cardiac surgery. It involved 70 individuals scheduled for elective open-heart surgery. All cases were randomly assigned into two groups of 35 patients. The study group replaced 100 mL of standard CPB priming solution with 100 mL of 20% human albumin. We measured serum albumin levels before and after the surgery, 6 and 12 h after, and calculated colloid oncotic pressure. Thorax CT scans were performed on the first postoperative day to measure and calculate pleural effusion volume. Results: Albumin addition to cardiopulmonary bypass priming solution led to a significant reduction in pleural effusion development after CPB. An albumin level <35 g/L after the surgery showed a significant increase in pleural effusion development, and 100 mL of 20% albumin was sufficient to maintain serum albumin levels > 35 g/L. Conclusions: Our study suggests a link between postoperative hypoalbuminemia and the early development of pleural effusion after CPB, as well as the possible benefits of adding 100 mL of 20% albumin compared to standard crystalloid CPB priming to minimize postoperative pleural effusion development.

Perioperative fluid management: evidence-based consensus recommendations from the international multidisciplinary PeriOperative Quality Initiative

Fluid therapy is an integral component of perioperative management. In light of emerging evidence in this area, the Perioperative Quality Initiative (POQI) convened an international multiprofessional expert meeting to generate evidence-based consensus recommendations for fluid management in patients undergoing surgery. This article provides a summary of the recommendations for perioperative fluid management of surgical patients from the preoperative period until hospital discharge and for all types of elective and emergency surgery, apart from burn injuries and head and neck surgery. Where evidence was lacking, recommendations for future research were generated. Specific recommendations are made for fluid management in elective major noncardiac surgery, cardiopulmonary bypass, thoracic surgery, neurosurgery, minor noncardiac surgery under general anaesthesia, and critical illness. There are ongoing gaps in knowledge resulting in variation in practice and some disagreement with our consensus recommendations. Perioperative fluid management should be individualised, taking into account the type of surgery and important patient factors, including intravascular volume status and acute and chronic comorbidities. Recommendations are made for further research in perioperative fluid management to address important gaps.

Renal dysfunction in surgical patients

PURPOSE OF REVIEW

To provide an overview of the current diagnostic criteria for acute kidney injury (AKI) including their limitations and to discuss prevention and treatment approaches in the perioperative setting.

RECENT FINDINGS

AKI is common in the perioperative period and is associated with worse short- and long-term outcomes. Current definitions of AKI have several limitations and lead to delayed recognition of kidney dysfunction which is why novel diagnostic approaches by using renal biomarkers may be helpful. In general, prevention of the development and progression of AKI is vital as a causal treatment for AKI is currently not available. Optimization of kidney perfusion and avoidance of nephrotoxic drugs reduce the occurrence of AKI in surgical patients. Angiotensin II as a new vasopressor, the use of remote ischemic preconditioning, and amino acids may be approaches with a positive effect on the kidneys.

SUMMARY

Evidence suggests that the implementation of supportive measures in patients at high risk for AKI might reduce the occurrence of AKI. Novel biomarkers can help allocating resources by detecting patients at high risk for AKI.

Systemic capillary leak syndrome

The vascular endothelial barrier maintains intravascular volume and metabolic homeostasis. Although plasma fluids and proteins extravasate continuously from tissue microvasculature (capillaries, post-capillary venules), systemic vascular leakage increases in critical illness associated with sepsis, burns and trauma, among others, or in association with certain drugs or toxin exposures. Systemically dysregulated fluid homeostasis, which can lead to hypovolaemia, hypotensive shock and widespread tissue oedema, has been termed systemic capillary leak syndrome (SCLS) when overt secondary causes (for example, heart or liver failure) are excluded. In severe forms, SCLS is complicated by compartment syndrome in the extremities and multi-organ dysfunction syndrome due to shock and systemic hypoperfusion. The different forms of SCLS include idiopathic SCLS (ISCLS) and secondary SCLS (SSCLS), which can be triggered by several conditions, including certain infections and haematological malignancies. A subgroup of patients with ISCLS have monoclonal gammopathy-associated SCLS (also known as Clarkson disease), which is an ultra-rare and extreme form of ISCLS. ISCLS can be managed effectively with monthly prophylactic immunoglobulin therapy whereas SSCLS frequently does not recur once the underlying condition resolves or the offending agent is discontinued. Thus, differentiation between ISCLS, SSCLS and other causes of oedema is crucial for quick diagnosis and positive patient outcomes.

Perioperative Albumin Among Adults Undergoing Thoracic Surgery in the United States: Utilization, Associations With Clinical Outcomes, and Contribution to Hospital Costs

OBJECTIVES

To estimate the use of albumin among adults undergoing thoracic surgery in the United States, compare baseline characteristics, clinical and cost outcomes of recipients versus nonrecipients, and determine albumin's contribution to total hospital costs.

DESIGN

Retrospective cohort study.

SETTING

Nationwide sample of US hospitals.

PARTICIPANTS

Adults undergoing open and minimally invasive thoracic surgery between 2011 and 2017.

INTERVENTIONS

Albumin on the day of surgery (identified using itemized hospital billing logs).

MEASUREMENTS AND MAIN RESULTS

Albumin was used in 170 of 342 US hospitals, among 13% and 7% of 14,672 and 22,532 patients who, respectively, underwent open and minimally invasive thoracic surgery (median volume 500 mL). Baseline comorbidities and organ-supportive treatments were several-fold more prevalent among recipients (particularly vasopressors, mechanical ventilation, and red cell transfusions). In standardized mortality ratio propensity score weighted analysis, albumin use was not associated with in-hospital mortality (adjusted relative risk 1.17 [0.72, 1.92] and 1.51 [0.97, 2.34], with open and minimally invasive procedures), but was associated with morbidity and higher costs, more so with minimally invasive procedures than with open surgery. Total costs among recipients were higher by $4,744 ($3,591, $5,897) and $5,088 ($4,075, $6,100) for open and minimally invasive procedures, respectively. Albumin accounted for 2.6% of this difference (median $124 [$83-$189] per patient).

CONCLUSIONS

Albumin use varies widely across hospitals, and 9% of patients receive it (median 500 mL). Use was not associated with in-hospital mortality and was associated with more morbidity and cost. The cost of albumin accounted for a trivial portion of hospital costs. Clinical trials must examine the effects of albumin on complications and costs after thoracic surgery.

Comparison of 4% Albumin and Ringer's Acetate on Hemodynamics in On-pump Cardiac Surgery: An Exploratory Analysis of a Randomized Clinical Trial

OBJECTIVES

Compare hemodynamics between 4% albumin and Ringer's acetate.

DESIGN

Exploratory analysis of the double-blind randomized ALBumin In Cardiac Surgery trial.

SETTING

Single-center study in Helsinki University Hospital.

PARTICIPANTS

We included 1,386 on-pump cardiac surgical patients.

INTERVENTION

We used 4% albumin or Ringer's acetate administration for cardiopulmonary bypass priming, volume replacement intraoperatively and 24 hours postoperatively.

MEASUREMENTS AND MAIN RESULTS

Hypotension (time-weighted average mean arterial pressure of <65 mmHg) and hyperlactatemia (time-weighted average blood lactate of >2 mmol/L) incidences were compared between trial groups in the operating room (OR), and early (0-6 hours) and late (6-24 hours) postoperatively. Associations of hypotension and hyperlactatemia with the ALBumin In Cardiac Surgery primary outcome (≥1 major adverse event [MAE]) were studied. In these time intervals, hypotension occurred in 118, 48, and 17 patients, and hyperlactatemia in 313, 131, and 83 patients. Hypotension and hyperlactatemia associated with MAE occurrence. Hypotension did not differ between the groups (albumin vs Ringer's: OR, 8.8% vs 8.5%; early postoperatively, 2.7% vs 4.2%; late postoperatively, 1.2% vs 1.3%; all p > 0.05). In the albumin group, hyperlactatemia was less frequent late postoperatively (2.9% vs 9.1%; p < 0.001), but not earlier (OR, 22.4% vs 23.6%; early postoperatively, 7.9% vs 11.0%; both p > 0.025 after Bonferroni-Holm correction).

CONCLUSIONS

In on-pump cardiac surgery, hypotension and hyperlactatemia are associated with the occurrence of ≥1 MAE. Compared with Ringer's acetate, albumin did not decrease hypotension and decreased hyperlactatemia only late postoperatively. Albumin's modest hemodynamic effect is concordant with the finding of no difference in MAEs between albumin and Ringer's acetate in the ALBumin In Cardiac Surgery trial.

Lactated Ringers, albumin and mannitol as priming during cardiopulmonary bypass reduces pulmonary edema in rats compared with hydroxyethyl starch

BACKGROUND

Endothelial disorders with edema formation and microcirculatory perfusion disturbances are common in cardiac surgery with cardiopulmonary bypass (CPB) and contribute to disturbed tissue oxygenation resulting in organ dysfunction. Albumin is protective for the endothelium and could be a useful additive to CPB circuit priming. Therefore, this study aimed to compare organ edema and microcirculatory perfusion in rats on CPB primed with lactated Ringers, albumin and mannitol (LR/albumin/mannitol) compared to 6% hydroxyethyl starch (HES).

RESULTS

Male rats were subjected to 75 min of CPB primed with either LR/albumin/mannitol or with 6% HES. Renal and lung edema were determined by wet/dry weight ratio. Pulmonary wet/dry weight ratio was lower in rats on CPB primed with LR/albumin/mannitol compared to HES (4.77 [4.44-5.25] vs. 5.33 [5.06-6.33], p = 0.032), whereas renal wet/dry weight ratio did not differ between groups (4.57 [4.41-4.75] vs. 4.51 [4.47-4.73], p = 0.813). Cremaster microcirculatory perfusion was assessed before, during and after CPB with intravital microscopy. CPB immediately impaired microcirculatory perfusion compared to baseline (LR/albumin/mannitol: 2 [1-7] vs. 14 [12-16] vessels per recording, p = 0.008; HES: 4 [2-6] vs. 12 [10-13] vessels per recording, p = 0.037), which persisted after weaning from CPB without differences between groups (LR/albumin/mannitol: 5 [1-9] vs. HES: 1 [0-4], p = 0.926). In addition, rats on CPB primed with LR/albumin/mannitol required less fluids to reach sufficient flow rates (0.5 [0.0-5.0] mL vs. 9 [4.5-10.0], p < 0.001) and phenylephrine (20 [0-40] µg vs. 90 [40-200], p = 0.004). Circulating markers for inflammation (interleukin 6 and 10), adhesion (ICAM-1), glycocalyx shedding (syndecan-1) and renal injury (NGAL) were determined by ELISA or Luminex. Circulating interleukin-6 (16 [13-25] vs. 33 [24-51] ng/mL, p = 0.006), interleukin-10 (434 [295-782] vs. 2120 [1309-3408] pg/ml, p < 0.0001), syndecan-1 (5 [3-7] vs. 15 [11-16] ng/mL, p < 0.001) and NGAL (555 [375-1078] vs. 2200 [835-3671] ng/mL, p = 0.008) were lower in rats on CPB primed with LR/albumin/mannitol compared to HES.

CONCLUSION

CPB priming with LR, albumin and mannitol resulted in less pulmonary edema, renal injury, inflammation and glycocalyx degradation compared to 6% HES. Furthermore, it enhanced hemodynamic stability compared with HES. Further research is needed to explore the specific role of albumin as a beneficial additive in CPB priming.

High intraoperative fluid load associated with prolonged length of hospital stay and complications after non-cardiac surgery in neonates

Inappropriate perioperative fluid load can lead to postoperative complications and death. This retrospective study was designed to investigate the association between intraoperative fluid load and outcomes in neonates undergoing non-cardiac surgery. From April 2020 to September 2022, 940 neonates who underwent non-cardiac surgery were retrospectively enrolled and their perioperative data were harvested for further analysis. According to recorded intraoperative fluid volumes defined as ml.kg-1 h-1, patients were mandatorily divided into quintile with fluid load as restrictive (quintile 1, Q1), moderately restrictive (Q2), moderate (Q3), moderately liberal (Q4), and liberal (Q5). The primary outcomes were defined as prolonged length of hospital stay (LOS) (postoperative LOS ≥ 14 days), complications beyond prolonged LOS, and 30-day mortality. Secondary outcomes included postoperative complications within 14 days of hospital stay. The intraoperative fluid load was in Q1 of 6.5 (5.3-7.3) (median and IQR); Q2: 9.2 (8.7-9.9); Q3: 12.2 (11.4-13.2); Q4: 16.5 (15.4-18.0); and Q5: 26.5 (22.3-32.2) ml.kg-1 h-1. The odd of prolonged LOS was positively correlated with an increase fluid volume (Q5 quintile: OR 2.602 [95% CI 1.444-4.690], P = 0.001), as well as complications beyond prolonged LOS (Q5: OR 3.322 [95% CI 1.656-6.275], P = 0.001). The overall 30-day mortality rate was increased with high intraoperative fluid load but did not reach to a statistical significance after adjusted with confounders. Furthermore, the highest quintile of fluid load (26.5 ml.kg-1 h-1, IQR [22.3-32.2]) (Q5 quintile) was significantly associated with longer postoperative mechanical ventilation time compared with Q1 (Q5: OR 2.212 [95% CI 1.101-4.445], P = 0.026).    Conclusion: Restrictive intraoperative fluid load had overall better outcomes, whilst high fluid load was significantly associated with prolonged LOS and complications after non-cardiac surgery in neonates.    Trial registration:  Chictr.org.cn Identifier: ChiCTR2200066823 (December 19, 2022). What is Known: • Inappropriate perioperative fluid load can lead to postoperative complications and even death. What is New: • High perioperative fluid load was significantly associated with an increased length of stay after non-cardiac surgery in neonates, whilst low fluid load was consistently related to better postoperative outcomes.

Management of Post-cardiotomy Shock

Patients undergoing cardiac surgery experience significant physiologic derangements that place them at risk for multiple shock phenotypes. Any combination of cardiogenic, obstructive, hemorrhagic, or vasoplegic shock occurs commonly in post-cardiotomy patients. The approach to the diagnosis and management of these shock states has many facets that are distinct compared to non-surgical cardiac intensive care unit patients. Additionally, the approach to and associated outcomes of cardiac arrest in the post-cardiotomy population are uniquely characterized by emergent bedside resternotomy if the circulation is not immediately restored. This review focuses on the unique aspects of the diagnosis and management of post-cardiotomy shock.

Use of Intravenous Albumin: A Guideline From the International Collaboration for Transfusion Medicine Guidelines

BACKGROUND

Albumin is used commonly across a wide range of clinical settings to improve hemodynamics, to facilitate fluid removal, and to manage complications of cirrhosis. The International Collaboration for Transfusion Medicine Guidelines developed guidelines for the use of albumin in patients requiring critical care, undergoing cardiovascular surgery, undergoing kidney replacement therapy, or experiencing complications of cirrhosis.

STUDY DESIGN AND METHODS

Cochairs oversaw the guideline development process and the panel included researchers, clinicians, methodologists, and a patient representative. The evidence informing this guideline arises from a systematic review of randomized clinical trials and systematic reviews, in which multiple databases were searched (inception through November 23, 2022). The panel reviewed the data and formulated the guideline recommendations using Grading of Recommendations Assessment, Development, and Evaluation methodology. The guidelines were revised after public consultation.

RESULTS

The panel made 14 recommendations on albumin use in adult critical care (three recommendations), pediatric critical care (one recommendation), neonatal critical care (two recommendations), cardiovascular surgery (two recommendations), kidney replacement therapy (one recommendation), and complications of cirrhosis (five recommendations). Of the 14 recommendations, two recommendations had moderate certainty of evidence, five recommendations had low certainty of evidence, and seven recommendations had very low certainty of evidence. Two of the 14 recommendations suggested conditional use of albumin for patients with cirrhosis undergoing large-volume paracentesis or with spontaneous bacterial peritonitis. Twelve of 14 recommendations did not suggest albumin use in a wide variety of clinical situations where albumin commonly is transfused.

INTERPRETATION

Currently, few evidence-based indications support the routine use of albumin in clinical practice to improve patient outcomes. These guidelines provide clinicians with actionable recommendations on the use of albumin.

Use of colloids and crystalloids for perioperative clinical infusion management in cardiac surgery patients and postoperative outcomes: a meta-analysis

BACKGROUND

The optimal fluid management strategy for patients undergoing cardiac surgery was controversial regarding fluid volume and intraoperative fluid types. This study aimed to assess the correlation between colloids and crystalloids used for perioperative fluid therapy in cardiac surgery patients and postoperative prognosis.

METHODS

The Ovid MEDLINE(R) ALL, Embase, and Cochrane Central Register of Controlled Trials databases were searched for eligible studies on fluid management strategies using colloids and crystalloids for cardiac surgery patients published before August 25th, 2023.

RESULTS

Ten randomized controlled trials met the eligibility criteria. Compared to the use of crystalloids, the use of colloids, including hydroxyethyl starch (HES), albumin, and gelatine, did not show any differences in mortality, transfusion, acute kidney injury, and atrial fibrillation rates, postoperative blood loss, the length of hospital stay, or the length of intensive care unit (ICU) stay. The results of this meta-analysis showed that the crystalloid group had significantly reduced postoperative chest tube output compared to the colloid group. In the subgroup analysis, the amount of fresh frozen plasma (FFP) infused was significantly lower when using fluid management in the ICU and when using isotonic crystalloids compared to the colloids. In addition, when using fluid management in the ICU, patients in the colloid group had a significant increase in urine volume 24 h after surgery. However, other related factors, including the type of crystalloid solution, type of colloidal solution, and timing of liquid management, did not affect most outcomes.

CONCLUSION

Both colloids and crystalloids could be used as alternatives for perioperative fluid management after cardiac surgery. The use of crystalloids significantly reduced the postoperative chest tube output, and the need for FFP infusion decreased significantly with the use of isotonic crystalloids or fluid management during the ICU stay. ICU patients in the colloid group had higher urine output 24 h after surgery. In addition, although the infusion method was not related to most outcomes, the rates of red blood cell and FFP transfusion and postoperative blood loss in the crystalloid group seemed to be lower, which needed to be further studied in high-quality and large-sample RCTs.

TRIAL REGISTRATION

PROSPERO, CRD42023415234.

The effect of human albumin administration on postoperative renal function following major surgery: a systematic review and meta-analysis

Optimal fluid management during major surgery is of considerable concern to anesthesiologists. Although crystalloids are the first choice for fluid management, the administration of large volumes of crystalloids is associated with poor postoperative outcomes. Albumin can be used for fluid management and may protect renal function. However, data regarding the effects of albumin administration on kidney function are conflicting. As such, the present study aimed to investigate the effect of albumin administration on renal function in patients undergoing major surgery and compare its effects with those of crystalloid fluid. The Embase, Medline, Web of Science, Cochrane Library, and KoreaMed databases were searched for relevant studies. The primary endpoint of the meta-analysis was the incidence of postoperative kidney injury, including acute kidney injury and renal replacement therapy. Twelve studies comprising 2311 patients were included; the primary endpoint was analyzed in four studies comprising 1749 patients. Perioperative albumin levels in patients undergoing major surgery did not significantly influence kidney dysfunction (p = 0.98). Postoperative fluid balance was less positive in patients who underwent major surgery and received albumin than in those who received crystalloids. Owing to the limitations of this meta-analysis, it remains unclear whether albumin administration during major surgery is better than crystalloid fluid for improving postoperative renal function.

Optimization of kidney function in cardiac surgery patients with intra-abdominal hypertension: expert opinion

Cardiac surgery-associated acute kidney injury (CSA-AKI) affects up to 42% of cardiac surgery patients. CSA-AKI is multifactorial, with low abdominal perfusion pressure often overlooked. Abdominal perfusion pressure is calculated as mean arterial pressure minus intra-abdominal pressure (IAP). IAH decreases cardiac output and compresses the renal vasculature and renal parenchyma. Recent studies have highlighted the frequent occurrence of IAH in cardiac surgery patients and have linked the role of low perfusion pressure to the occurrence of AKI. This review and expert opinion illustrate current evidence on the pathophysiology, diagnosis, and therapy of IAH and ACS in the context of AKI.

Twenty percent human albumin solution fluid bolus administration therapy in patients after cardiac surgery-II: a multicentre randomised controlled trial

PURPOSE

After cardiac surgery, fluid bolus therapy (FBT) with 20% human albumin may facilitate less fluid and vasopressor administration than FBT with crystalloids. We aimed to determine whether, after cardiac surgery, FBT with 20% albumin reduces the duration of vasopressor therapy compared with crystalloid FBT.

METHODS

We conducted a multicentre, parallel-group, open-label, randomised clinical trial in six intensive care units (ICUs) involving cardiac surgery patients deemed to require FBT. We randomised 240 patients to receive up to 400 mL of 20% albumin/day as FBT, followed by 4% albumin for any subsequent FBT on that day, or to crystalloid FBT for at least the first 1000 mL, with use of crystalloid or 4% albumin FBT thereafter. The primary outcome was the cumulative duration of vasopressor therapy. Secondary outcomes included fluid balance.

RESULTS

Of 480 randomised patients, 466 provided consent and contributed to the primary outcome (mean age 65 years; median EuroSCORE II 1.4). The cumulative median duration of vasopressor therapy was 7 (interquartile range [IQR] 0-19.6) hours with 20% albumin and 10.8 (IQR 0-22.8) hours with crystalloids (difference - 3.8 h, 95% confidence interval [CI] - 8 to 0.4; P = 0.08). Day one fluid balance was less with 20% albumin FBT (mean difference - 701 mL, 95% CI - 872 to - 530).

CONCLUSIONS

In patients after cardiac surgery, when compared to a crystalloid-based FBT, 20% albumin FBT was associated with a reduced positive fluid balance but did not significantly reduce the duration of vasopressor therapy.

Cardiac Surgery-Associated Acute Kidney Injury

AKI is a common and serious complication of cardiac surgery that has a significant impact on patient morbidity and mortality. The Kidney Disease Improving Global Outcomes definition of AKI is widely used to classify and identify AKI associated with cardiac surgery (cardiac surgery-associated AKI [CSA-AKI]) on the basis of changes in serum creatinine and/or urine output. There are various preoperative, intraoperative, and postoperative risk factors for the development of CSA-AKI which should be recognized and addressed as early as possible to expedite its diagnosis, reduce its occurrence, and prevent or ameliorate its devastating complications. Crucial issues are the inaccuracy of serum creatinine as a surrogate parameter of kidney function in the perioperative setting of cardiothoracic surgery and the necessity to discover more representative markers of the pathophysiology of AKI. However, except for the tissue inhibitor of metalloproteinase-2 and insulin-like growth factor binding protein 7 ratio, other diagnostic biomarkers with an acceptable sensitivity and specificity are still lacking. This article provides a comprehensive review of various aspects of CSA-AKI, including pathogenesis, risk factors, diagnosis, biomarkers, classification, prevention, and treatment management.

Reduce intraoperative albumin utilisation in cardiac surgical patients: a quality improvement initiative

BACKGROUND

Albumin continues to be used routinely by cardiac anaesthesiologists perioperatively despite lack of evidence for improved outcomes. The Multicenter Perioperative Outcomes Group (MPOG) data ranked our institution as one of the highest intraoperative albumin users during cardiac surgery. Therefore, we designed a quality improvement project (QIP) to introduce a bundle of interventions to reduce intraoperative albumin use in cardiac surgical patients.

METHODS

Our institutional MPOG data were used to analyse the FLUID-01-C measure that provides the number of adult cardiac surgery cases where albumin was administered intraoperatively by anaesthesiologists from 1 July 2019 to 30 June 2022. The QIP involved introduction of the following interventions: (1) education about appropriate albumin use and indications (January 2021), (2) email communications reinforced with OR teaching (March 2021), (3) removal of albumin from the standard pharmacy intraoperative medication trays (April 2021), (4) grand rounds presentation discussing the QIP and highlighting the interventions (May 2021) and (5) quarterly provider feedback (starting July 2021). Multivariable segmented regression models were used to assess the changes from preintervention to postintervention time period in albumin utilisation, and its total monthly cost.

RESULTS

Among the 5767 cardiac surgery cases that met inclusion criteria over the 3-year study period, 16% of patients received albumin intraoperatively. The total number of cases that passed the metric (albumin administration was avoided), gradually increased as our interventions went into effect. Intraoperative albumin utilisation (beta=-101.1, 95% CI -145 to -56.7) and total monthly cost of albumin (beta=-7678, 95% CI -10712 to -4640) demonstrated significant decrease after starting the interventions.

CONCLUSIONS

At a single academic cardiac surgery programme, implementation of a bundle of simple and low-cost interventions as part of a coordinated QIP were effective in significantly decreasing intraoperative use of albumin, which translated into considerable costs savings.

Days alive and out of hospital for adult female and male cardiac surgery patients: a population-based cohort study

BACKGROUND

Research shows women experience higher mortality than men after cardiac surgery but information on sex-differences during postoperative recovery is limited. Days alive and out of hospital (DAH) combines death, readmission and length of stay, and may better quantify sex-differences during recovery. This main objective is to evaluate (i) how DAH at 30-days varies between sex and surgical procedure, (ii) DAH responsiveness to patient and surgical complexity, and (iii) longer-term prognostic value of DAH.

METHODS

We evaluated 111,430 patients (26% female) who underwent one of three types of cardiac surgery (isolated coronary artery bypass [CABG], isolated non-CABG, combination procedures) between 2009 - 2019. Primary outcome was DAH at 30 days (DAH30), secondary outcomes were DAH at 90 days (DAH90) and 180 days (DAH180). Data were stratified by sex and surgical group. Unadjusted and risk-adjusted analyses were conducted to determine the association of DAH with patient-, surgery-, and hospital-level characteristics. Patients were divided into two groups (below and above the 10th percentile) based on the number of days at DAH30. Proportion of patients below the 10th percentile at DAH30 that remained in this group at DAH90 and DAH180 were determined.

RESULTS

DAH30 were lower for women compared to men (22 vs. 23 days), and seen across all surgical groups (isolated CABG 23 vs. 24, isolated non-CABG 22 vs. 23, combined surgeries 19 vs. 21 days). Clinical risk factors including multimorbidity, socioeconomic status and surgical complexity were associated with lower DAH30 values, but women showed lower values of DAH30 compared to men for many factors. Among patients in the lowest 10th percentile at DAH30, 80% of both females and males remained in the lowest 10th percentile at 90 days, while 72% of females and 76% males remained in that percentile at 180 days.

CONCLUSION

DAH is a responsive outcome to differences in patient and surgical risk factors. Further research is needed to identify new care pathways to reduce disparities in outcomes between male and female patients.

Improving appropriate use of intravenous albumin: results of a single-centre audit and multifaceted intervention

BACKGROUND

Intravenous albumin has limited indications supported by randomised controlled trials, yet it is often prescribed for indications not supported by evidence.

AIM

To reduce unnecessary transfusion of albumin.

INTERVENTIONS

Under the leadership of a multidisciplinary quality improvement team, evidence-based recommendations were disseminated in tandem with a new electronic order set, an educational strategy, qualitative interviews with prescribers and a return policy change to reduce wastage.

IMPLEMENTATION AND EVALUATION

Interventions were introduced in a staggered fashion. The primary outcome, appropriate use of albumin, was monitored and quantified using pre-intervention and post-intervention audits. Process measures included statistical process run charts of monthly usage of 5% and 25% albumin and wastage. Data on length of stay (hospital and intensive care), new inpatient starts on kidney replacement and mortality were collected as balancing measures.

RESULTS

Appropriate albumin usage based on indication increased from 30% to 50% (p<0.0001). There was significantly less overall albumin usage in the post-intervention period compared with the pre-intervention period (negative coefficient, p<0.0001), driven by a major reduction in the utilisation of the 5% formulation (p<0.0001). Overall albumin usage was significantly lower in the post-intervention period, decreasing from 800 to 450 vials per month. The intervention resulted in significantly less wastage (negative coefficient, p=0.017). Mortality, length of stay and new starts on kidney replacement therapy remained constant throughout the study period.

CONCLUSION

Improved prescribing of albumin was achieved with a multifaceted approach. Substantial and sustained reductions in usage were achieved without negatively impacting patient-important outcomes. The estimated annual savings for the purchase cost of albumin was CAN $300 000. We provide a structured process for other organisations to optimise their use of albumin.

Association of Sarcopenia, as Defined Based on the Skeletal Muscle Index, With Mortality and Morbidity After Cardiac Surgery: A Retrospective Cohort Study

OBJECTIVE

To investigate whether "sarcopenia," defined based on the preoperative skeletal muscle index (SMI), can predict major postoperative morbidity and all-cause mortality.

DESIGN

A retrospective observational cohort study.

SETTING

At the authors' Department of Critical Care Medicine.

PARTICIPANTS

A total of 986 adult Chinese patients underwent cardiac surgery (coronary artery bypass graft, valve surgery, combined surgery, or aortic surgery) between January 2019 and August 2022.

MEASUREMENTS AND MAIN RESULTS

The skeletal muscle area at the third lumbar level (L3) was measured via preoperative computed tomography (up to 3 months from the date of imaging to the date of surgery) and normalized to patient height (skeletal muscle index). Sarcopenia was determined based on the skeletal muscle index being in the lowest sex-specific quartile. The primary outcome was all-cause mortality. The secondary outcome was major morbidity. A total of 968 patients were followed for a median of 2.00 years, ranging from 1.06 to 2.90 years. After the follow-up, 76 patients died during the follow-up period. Multivariate Cox proportional analysis showed a relationship between sarcopenia (adjusted hazard ratio 1.80, 95% CI 1.04-3.11; p = 0.034) and all-cause mortality. Kaplan-Meier curves revealed a significantly lower survival rate in the sarcopenia group than in the nonsarcopenia group. Overall, 199 (20.6%) patients had major morbidity. Multivariate analysis showed a significant relationship between sarcopenia (adjusted odds ratio = 2.21, 95% CI 1.52∼3.22, p < 0.001) and major morbidity.

CONCLUSIONS

Sarcopenia, defined by the skeletal muscle index, is associated with all-cause mortality and major morbidity after cardiac surgery, thereby suggesting the need for perioperative sarcopenia risk assessment for patients undergoing cardiac surgery to guide the prevention and management of adverse outcomes.

The clinical significance of hypoalbuminaemia

Albumin is a relatively small molecule with a radius of 7.5 nm and a molecular weight of 65 kDa. It is the most abundant protein in plasma, accounting for 60-75% of its oncotic pressure. Its concentration in plasma is merely one static measurement reflecting a dynamic and complex system of albumin physiology, and is the net result of several different processes, one or more of which may become deranged by disease or its treatment. It is also unsurprising that hypoalbuminaemia has proved to be an indicator of morbidity and mortality risk since the underlying conditions which cause it, including protein energy malnutrition, crystalloid overload, inflammation, and liver dysfunction are themselves risk factors. In some cases, its underlying cause may require treatment but mostly it is just a parameter to be monitored and used as one measure of clinical progress or deterioration. While malnutrition, associated with a low protein intake, may be a contributory cause of hypoalbuminaemia, in the absence of inflammation and/or dilution with crystalloid its development in response to malnutrition alone is slow compared with the rapid change caused by inflammatory redistribution or dilution with crystalloids. Other significant causes include liver dysfunction and serous losses. These causal factors may occur singly or in combination in any particular case. Treatment is that of the underlying causes and associated conditions such as a low plasma volume, not of hypoalbuminaemia per se.

Acute kidney injury after cardiac surgery

PURPOSE OF REVIEW

Patients undergoing cardiac surgery are at high risk to develop cardiac surgery-associated acute kidney injury (CS-AKI) postoperatively. CS-AKI is associated with an increased risk for persistent renal dysfunction, morbidity and mortality. This review summarizes the epidemiology and pathophysiology of CS-AKI, as well as current treatment and prevention strategies.

RECENT FINDINGS

As AKI is a syndrome with complex pathophysiology, no causative treatment strategies exist. Recent advances in the field of AKI biomarkers offer new perspectives on the issue and the implementation of biomarker-guided preventive strategies may reduce rates of CS-AKI. Finally, nephroprotective treatments and angiotensin II as a novel vasopressor may offer new opportunities for high-risk patients undergoing cardiac surgery.

SUMMARY

Based on the described novel approaches for early detection, prevention and management of CS-AKI, a precision-medicine approach should be implemented in order to prevent the development of AKI in patients undergoing cardiac surgery.

Safety and Efficacy of Albumin for Pump Priming in Cardiac Surgery: A Meta-Analysis

OBJECTIVES

To assess the efficacy and safety of albumin as pump priming fluid in cardiac surgery.

DESIGN

Meta-analysis of randomized controlled trials.

SETTING

Each study was conducted in a surgical center or intensive care unit.

PARTICIPANTS

Adult and pediatric patients undergoing cardiac surgery with cardiopulmonary bypass who received circuit priming fluids.

INTERVENTIONS

Extracorporeal circuit priming with either albumin or crystalloid.

MEASUREMENTS AND RESULTS

Fourteen eligible randomized controlled trials with 741 patients were included in the present meta-analysis. Albumin prime had lower bleeding (CI -202.20 to -142.88 mL, p < 0.00001) and showed a greater advantage in preserving platelet counts (CI 14.85-21.48 × 103 mm-3, p < 0.00001), maintaining colloid osmotic pressure and sustaining negative fluid balance. No significant differences were found in the remaining study outcomes.

CONCLUSIONS

Albumin was shown to be safe and efficacious in extracorporeal circulation perfusion. However, its clinical advantages were not clearly highlighted, as there were no significant differences in the number of deaths, length of hospital stay, or intensive care unit duration. The results should be interpreted cautiously, as most included studies were small in scale, and the total number of participants was limited.

Effect of 5% albumin on endothelial glycocalyx degradation during off-pump coronary artery bypass

PURPOSE

The integrity of the endothelial glycocalyx (EG), a critical player in vascular homeostasis, reportedly influences the outcomes of critically ill patients. We investigated the effect of 5% albumin, which preserved EG integrity in preclinical studies, vs balanced crystalloid solution on EG degradation in patients undergoing off-pump coronary surgery.

METHODS

Patients were randomized to receive either 5% albumin (N = 51) or balanced crystalloid solution (Plasma-Lyte [Baxter Incorporated, Seoul, Republic of Korea]; N = 53) for intravenous volume replacement during surgery (double-blinded). The primary outcome was plasma syndecan-1 concentration, a marker of EG degradation, measured after anesthetic induction (baseline), completion of grafting, and sternal closure. Secondary outcomes were atrial natriuretic peptide (ANP), tumour necrosis factor (TNF)-α, soluble thrombomodulin, and perioperative fluid balance.

RESULTS

The mean (standard deviation) fluid requirements were 833 (270) mL and 1,323 (492) mL in the albumin and Plasma-Lyte group, respectively (mean difference, -489 mL; 95% confidence interval [CI], -643 to -335; P < 0.001). Plasma syndecan-1 concentration increased after completion of grafting (median difference, 116 ng·mL-1; 95% CI, 67 to 184; P < 0.001) and sternal closure (median difference, 57 ng·mL-1; 95% CI, 36 to 80; P < 0.001) compared with those at baseline, without any intergroup differences. Atrial natriuretic peptide, TNF-α, and soluble thrombomodulin concentrations were similar between the two groups. The amount of chest tube drainage was greater in the albumin group than that in the Plasma-Lyte group (median difference, 190 mL; 95% CI, 18 to 276; P = 0.03).

CONCLUSION

Off-pump coronary surgery was associated with significant EG degradation. Yet, intraoperative fluid therapy with 5% albumin could not ameliorate EG degradation when compared with balanced crystalloid solution.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT03699462); first posted 9 October 2018.

Intravenous albumin in cardiac and vascular surgery: a systematic review and meta-analysis

BACKGROUND

Intravenous albumin is commonly utilised in cardiovascular surgery for priming of the cardiopulmonary bypass circuit, volume replacement, or both, although the evidence to support this practice is uncertain. The aim was to compare i.v. albumin with synthetic colloids and crystalloids for paediatric and adult patients undergoing cardiovascular surgery for all-cause mortality and other perioperative outcomes.

METHODS

A systematic review and meta-analysis of randomised controlled trials (RCTs) of i.v. albumin compared with synthetic colloids and crystalloids on the primary outcome of all-cause mortality was conducted. Secondary outcomes included renal failure, blood loss, duration of hospital or intensive care unit stay, cardiac index, and blood component use; subgroups were analysed by age, comparator fluid, and intended use (priming, volume, or both). We searched MEDLINE, Embase, and Cochrane Central Register of Controlled Trials (CCRT) from 1946 to November 23, 2022.

RESULTS

Of 42 RCTs, mortality was assessed in 15 trials (2711 cardiac surgery patients) and the risk difference was 0.00, 95% confidence interval (CI) -0.01 to 0.01, I2=0%. Among secondary outcomes, i.v. albumin resulted in smaller fluid balance, mean difference -0.55 L, 95% CI -1.06 to -0.4, I2=90% (nine studies, 1975 patients) and higher albumin concentrations, mean difference 7.77 g L-1, 95% CI 3.73-11.8, I2=95% (six studies, 325 patients).

CONCLUSIONS

Intravenous albumin use was not associated with a difference in morbidity and mortality in patients undergoing cardiovascular surgery, when compared with comparator fluids. The lack of improvement in important outcomes with albumin and its higher cost suggests it should be used restrictively.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO; CRD42020171876.

Effects of albumin and crystalloid priming strategies on red blood cell transfusions in on-pump cardiac surgery: a network meta-analysis

BACKGROUND

In on-pump cardiac surgery, the albumin priming strategy could maintain colloid osmotic pressure better than crystalloid solutions and reduce excessive perioperative fluid balance. However, a high-quality meta-analysis is required to compare the safety of these approaches in perioperative red blood cell (RBC) transfusions. Owing to limited direct evidence, we conducted a network meta-analysis (NMA) to increase the pool of studies and provide indirect evidence.

METHODS

The pre-defined primary outcomes were intraoperative and the first 24 h postoperative RBC transfusion volume in units. The pre-defined secondary outcome was postoperative blood loss (the first 24 h). We reviewed all randomized controlled trials comparing albumin, crystalloid, and artificial colloid priming strategies. Studies that only displayed pre-defined outcomes could be included. A pairwise meta-analysis was performed on studies that directly compared the pre-defined outcomes between albumin and crystalloids. Additionally, a random-effects network meta-analysis (NMA) model was employed to generate indirect evidence for the pre-defined outcomes between albumin and crystalloids.

RESULTS

The literature search identified 830 studies,10 of which were included in the final analysis. Direct meta-analysis indicated that crystalloid priming significantly decreased total perioperative RBC transfusions (MD: -0.68U; 95%CI: -1.26, -0.09U; P = 0.02) and intraoperative RBC transfusions (MD: -0.20U; 95%CI: -0.39, -0.01U; P = 0.03) compared to albumin. Postoperative RBC transfusions showed a decreasing trend in the crystalloid group; however, the difference was not statistically significant. (MD: -0.16U; 95%CI: -0.45, 0.14U; P = 0.30). After including indirect evidence, the NMA results continued to demonstrate a higher RBC receiving with the albumin priming strategy compared to crystalloids, although the differences did not reach statistical significance. For postoperative blood loss, direct evidence showed no significant differences between albumin and crystalloid priming strategies. However, NMA evidence displayed that albumin exist higher probability of reducing postoperative blood loss than crystalloid.

CONCLUSION

Both direct and NMA evidence indicated that the albumin priming strategy resulted in more perioperative RBC transfusions than crystalloids. Considering the additional blood management burden, the application of an albumin-priming strategy in on-pump cardiac surgery still needs more consideration.

Intravenous albumin utilization audit at a large community hospital

BACKGROUND

There is a literature gap in terms of albumin utilization practices.

METHODS/MATERIALS

We conducted a single-center retrospective observational electronic audit of adult admitted patients who received one or more vials of albumin (5% or 25%) between September 1, 2019 and August 31, 2020 at a large community hospital. The Research Ethics Board approval was obtained. Utilization data identified through the laboratory information system were independently adjudicated by two reviewers and resolved by consensus as appropriate-acceptable, appropriate-may be acceptable, or inappropriate. The primary objective of this audit is to determine the proportion of 5% and 25% intravenous albumin infusions meeting a priori appropriateness criteria for indication. Secondary outcomes include determining the patterns of practice surrounding intravenous albumin use: patient demographics, most responsible diagnosis, location at time of order, clinical outcomes of albumin recipients, and types, volumes, and cost of albumin infused.

RESULTS

The mean total albumin administered was 569.2 mL across 456 total recipients (58% male) with a 29% appropriateness rate. This cohort had an in-hospital mortality rate of 38%, with an average of 6 days from first dose of albumin to death. The mean length of stay was 14 days, with a mean intensive care length of stay of 8 days. The purchase cost of inappropriately transfused albumin was CAD $65,538.

CONCLUSION

Based on a lack of or an unacceptable indication provided, 71% of patients were inappropriately transfused. Albumin use deviating from guideline recommendations may be contributing to increased healthcare costs, pressure on limited supply, and potential patient harm.

Albumin and Cardioprotection in On-Pump Cardiac Surgery-A Post Hoc Analysis of a Randomized Trial

OBJECTIVES

To study the quantitative potency of plasma albumin on cardioprotection in terms of creatinine kinase-myocardial band mass (CK-MBm) in on-pump cardiac surgery.

DESIGN

Post hoc analysis of a double-blinded randomized clinical trial.

SETTING

Single-center study in the Helsinki University Hospital.

PARTICIPANTS

A total of 1,386 adult on-pump cardiac surgical patients.

INTERVENTION

Administration of 4% albumin (n = 693) or Ringers acetate (n = 693) for cardiopulmonary bypass priming and volume replacement intraoperatively and postoperatively during the first 24 hours.

MEASUREMENTS AND MAIN RESULTS

Albumin concentration was measured preoperatively and intraoperatively (after protamine administration), and CK-MBm on the first postoperative morning. Multivariate linear regression analyses were measured in the whole cohort and the Ringer group. Plasma albumin concentration did not differ between the groups preoperatively (Ringer v albumin: 38.3 ± 5.0 g/L v 38.6 ± 4.5 g/L; p = 0.171) but differed intraoperatively (29.5 ± 5.2 g/L v 41.5 ± 6.0 g/L; p < 0.001). Creatinine kinase-myocardial band mass was higher in the Ringer (32.0 ± 34.8 μg/L) than in the albumin group (24.3 ± 33.0 μg/L) (p < 0.001). Aortic cross-clamping time associated with CK-MBm in the whole cohort (standardized β = 0.376 [95% CI 0.315-0.437], p < 0.001) and the Ringer group (β = 0.363 [0.273-0.452]; p < 0.001). Albumin administration in the whole cohort (β = -0.156 [-0.201 to -0.111]; p < 0.001) and high intraoperative albumin concentration in the Ringer group (β = -0.07 [-0.140 to -0.003]; p = 0.04) associated with reduced CK-MBm. Compared with ischemia-induced increase in CK-MBm, albumin's potency to reduce CK-MBm was 41% in the whole cohort (β-value ratio of -0.156/0.376) and 19% in the Ringer group (β-value ratio of -0.07/0.363).

CONCLUSION

Both endogenous and exogenous albumin appear to be cardioprotective regarding CK-MBm release in on-pump cardiac surgery.

Capillary leak and endothelial permeability in critically ill patients: a current overview

Capillary leak syndrome (CLS) represents a phenotype of increased fluid extravasation, resulting in intravascular hypovolemia, extravascular edema formation and ultimately hypoperfusion. While endothelial permeability is an evolutionary preserved physiological process needed to sustain life, excessive fluid leak-often caused by systemic inflammation-can have detrimental effects on patients' outcomes. This article delves into the current understanding of CLS pathophysiology, diagnosis and potential treatments. Systemic inflammation leading to a compromise of endothelial cell interactions through various signaling cues (e.g., the angiopoietin-Tie2 pathway), and shedding of the glycocalyx collectively contribute to the manifestation of CLS. Capillary permeability subsequently leads to the seepage of protein-rich fluid into the interstitial space. Recent insights into the importance of the sub-glycocalyx space and preserving lymphatic flow are highlighted for an in-depth understanding. While no established diagnostic criteria exist and CLS is frequently diagnosed by clinical characteristics only, we highlight more objective serological and (non)-invasive measurements that hint towards a CLS phenotype. While currently available treatment options are limited, we further review understanding of fluid resuscitation and experimental approaches to target endothelial permeability. Despite the improved understanding of CLS pathophysiology, efforts are needed to develop uniform diagnostic criteria, associate clinical consequences to these criteria, and delineate treatment options.

Controversies Surrounding Albumin Use in Sepsis: Lessons from Cirrhosis

This narrative review critically examines the role of albumin in sepsis management and compares it to its well-established application in liver cirrhosis. Albumin, a key plasma protein, is effective in the management of fluid imbalance, circulatory dysfunction, and inflammation-related complications. However, its role in sepsis is more intricate and characterized by ongoing debate and varied results from clinical studies. In sepsis, the potential benefits of albumin include maintaining vascular integrity and modulating inflammation, yet its consistent clinical efficacy is not as definitive as that in cirrhosis. This review evaluated various clinical trials and evidence, highlighting their limitations and providing practical insights for clinicians. It emphasizes identifying sepsis patient subgroups that are most likely to benefit from albumin therapy, particularly exploring the correction of hypoalbuminemia. This condition, which is significantly corrected in patients with cirrhosis, may have similar therapeutic advantages in sepsis. The potential effectiveness of albumin in the low-volume resuscitation and deresuscitation phases of sepsis management was noted. Given the safety concerns observed in cirrhosis, such as pulmonary edema and hypervolemia associated with albumin therapy, cautious integration of albumin into sepsis treatment is mandatory. Personalized albumin therapy is advocated for tailoring strategies to the specific needs of each patient, based on their clinical presentation and underlying conditions. The need for further research to delineate the role of albumin in sepsis pathophysiology is underscored. The review emphasizes the importance of conducting trials to assess the effectiveness of albumin in correcting hypoalbuminemia in sepsis, its impact on patient outcomes, and the establishment of appropriate dosing and administration methods. This approach to albumin use in sepsis management is posited as a way to potentially improve patient outcomes in this complex clinical scenario while being mindful of the lessons learned from its use in cirrhosis.

Development of new colloid osmotic pressure measurement method using ultrafiltration membrane during cardiopulmonary bypass

BACKGROUND

Clinical practice of measuring colloid osmotic pressure (COP) was abandoned after correcting hypoosmolarity did not improve overall patient outcomes. However, the use of albumin and colloidal solutions has contributed to maintaining intraoperative and postoperative fluid balance at lower levels. Reduced perioperative fluid balance is consistently reported to have positive effects on clinical outcomes. Priming solutions for cardiopulmonary bypass typically include colloids; however, the optimal type of priming solution has not yet been determined. Stricter COP management may further improve postoperative courses. To achieve this, the widespread adoption of a measurement method suitable for COP monitoring during cardiopulmonary bypass is required.

METHODS

A test circuit was made which measured COP using an ultrafiltration membrane method based on the changes in hydrostatic pressure that occurs across a semipermeable membrane. We then compared the measurements obtained using this method with colloidal osmometer measurements.

RESULTS

COP measurements were obtained for a total of 100 tests (10 times each for 10 test solutions). The evaluation parameters included simultaneous reproducibility, correlation with the colloid osmometer, and measurement time. The results demonstrated high accuracy of the ultrafiltration membrane method, simultaneous reproducibility within 3%, a high positive correlation with the colloid osmometer (correlation coefficient: R2 = 0.99; p < 0.01), and equal time required for measurement.

CONCLUSION

Measuring COP using ultrafiltration membranes solves problems within existing measurement methods. Although further improvements in the method are necessary, it has implications for future research and clinical applications.

Albumin administration in internal medicine: A journey between effectiveness and futility

Albumin is the most abundant circulating protein and provides about 70% of the plasma oncotic power. The molecule also carries many other biological functions (binding, transport and detoxification of endogenous and exogenous compounds, antioxidation, and modulation of inflammatory and immune responses). Hypoalbuminemia is a frequent finding in many diseases, representing usually only a biomarker of poor prognosis rather than a primary pathophysiological event. Despite that, albumin is prescribed in many conditions based on the assumption that correction of hypoalbuminemia would lead to clinical benefits for the patients. Unfortunately, many of these indications are not supported by scientific evidence (or have been even disproved), so that a large part of albumin use is nowadays still inappropriate. Decompensated cirrhosis is the clinical area where albumin administration has been extensively studied and solid recommendations can be made. Besides prevention and treatment of acute complications, long-term albumin administration in patients with ascites has emerged in the last decade has a potential new disease-modifying treatment. In non-hepatological settings, albumin is widely used for fluid resuscitation in sepsis and critical illnesses, with no clear superiority over crystalloids. In many other conditions, scientific evidence supporting albumin prescription is weak or even absent. Thus, given its high cost and limited availability, action is needed to avoid the use of albumin for inappropriate and futile indications to ensure its availability in those conditions for which albumin has been demonstrated to have a real effectiveness and an advantage for the patient.

Albumin Infusion and Blood Loss After Cardiac Surgery

BACKGROUND

In the recent ALBICS (ALBumin In Cardiac Surgery) trial, 4% albumin used for cardiopulmonary bypass priming and volume replacement increased perioperative bleeding compared with Ringer acetate. In the present exploratory study, albumin-related bleeding was further characterized.

METHODS

Ringer acetate and 4% albumin were compared in a randomized, double-blinded fashion in 1386 on-pump adult cardiac surgery patients. The study end points for bleeding were the Universal Definition of Perioperative Bleeding (UDPB) class and its components.

RESULTS

The UDPB bleeding grades were higher in the albumin group than the Ringer group: "insignificant" (albumin vs Ringer: 47.5% vs 62.9%), "mild" (12.7% vs 8.9%), "moderate" (28.7% vs 24.4%), "severe" (10.2% vs 3.2%), and "massive" (0.9% vs. 0.6%; P < .001). Patients in the albumin group received red blood cells (45.2% vs 31.5%; odds ratio [OR], 1.80; 95% CI, 1.44-2.24; P < .001), platelets (33.3% vs 21.8%; OR, 1.79; 95% CI, 1.41-2.28; P < .001), and fibrinogen (5.6% vs 2.6%; OR, 2.24; 95% CI, 1.27-3.95; P < .05), and underwent resternotomy (5.3% vs 1.9%; OR, 2.95; 95% CI, 1.55-5.60, P < .001) more often than patients in the Ringer group. The strongest predictors of bleeding were albumin group allocation (OR, 2.18; 95% CI, 1.74-2.74) and complex (OR, 2.61; 95% CI, 2.02-3.37) and urgent surgery (OR, 1.63; 95% CI, 1.26-2.13). In interaction analysis, the effect of albumin on the risk of bleeding was stronger in patients on preoperative acetylsalicylic acid.

CONCLUSIONS

Perioperative administration of albumin, compared with Ringer's acetate, resulted in increased blood loss and higher UDBP class. The magnitude of this effect was similar to the complexity and urgency of the surgery.

Postoperative free water administration is associated with dysnatremia after congenital heart disease surgery in infants

Dysnatremia after congenital heart disease (CHD) surgery is common. European guidelines on intraoperative fluid therapy in children recommend isotonic solutions to avoid hyponatremia, but prolonged cardiopulmonary bypass and administration of high sodium-containing solutions (i.e., blood products and sodium bicarbonate) are associated with postoperative hypernatremia. The aim of the study was to describe fluid composition prior to and during the development of postoperative dysnatremia. A retrospective observational, single-center study including infants undergoing CHD surgery. Demographics and clinical characteristics were registered. Highest and lowest plasma sodium values were recorded and associations with perioperative fluid administration, blood products, crystalloids, and colloids were explored in relation to three perioperative periods. Postoperative dysnatremia occurred in nearly 50% of infants within 48 h after surgery. Hypernatremia was mainly associated with administration of blood products (median [IQR]: 50.5 [28.4-95.5] vs. 34.5 [18.5-61.1] mL/kg; p = 0.001), and lower free water load (1.6 [1.1-2.2] mL/kg/h; p = 0.01). Hyponatremia was associated with a higher free water load (2.3 [1.7-3.3] vs. 1.8 [1.4-2.5] mL/kg/h; p = 0.001) and positive fluid balance. On postoperative day 1, hyponatremia was associated with higher volumes of free water (2.0 [1.5-2.8] vs. 1.3 [1.1-1.8] mL/kg/h; p < 0.001) and human albumin, despite a larger diuresis and more negative daily fluid balance. Postoperative hyponatremia occurred in 30% of infants despite restrictive volumes of hypotonic maintenance fluid, whereas hypernatremia was mainly associated with blood product transfusion. Individualized fluid therapy, with continuous reassessment to reduce the occurrence of postoperative dysnatremia is mandatory in pediatric cardiac surgery. Prospective studies to evaluate fluid therapy in pediatric cardiac surgery patients are warranted.

Year in Review 2022: Noteworthy Literature in Cardiac Anesthesiology

Last year researchers made substantial progress in work relevant to the practice of cardiac anesthesiology. We reviewed 389 articles published in 2022 focused on topics related to clinical practice to identify 16 that will impact the current and future practice of cardiac anesthesiology. We identified 4 broad themes including risk prediction, postoperative outcomes, clinical practice, and technological advances. These articles are representative of the best work in our field in 2022.

[Intensive Care in Heart Surgery - is All Now Different?]

With approximately 100000 operations performed in Germany per year, cardiac surgery is among the surgical specialties that require intensive care tratment most frequently. Although all therapeutic aspects of ICU treatment are of high importance among cardiac surgery patients, there is a focus on hemodynamics with the overarching goal of sufficient oxygen delivery. Patients undergoing cardiac surgery are particularily prone to hemodynamic instability and low cardiac output syndrome, potentially culminating into cardiogenic shock. This article presents an overview of essential elements of intensive care medicine in cardiac surgery, paying special attention to hemodynamic monitoring, low cardiac output syndrome, inotropy, cardiac arrhyhmia, perioperative myocardial infarction, and patient blood management.

[Cardioanaesthesiology - What's new?]

The still unchanged high morbidity and mortality of patients undergoing complex cardiac surgical procedures as well as developments in minimally invasive cardiac surgery are not only an ongoing challenge for all working in cardiac anaesthesia but also a chance for further developing this anaesthetic subdiscipline. Alongside the presentation of a case report, the present article gives an overview about recent developments in inotropic therapy, monitoring, the rational use of mechanical circulatory support, volume therapy, sedation, analgesia, and point-of-care coagulation monitoring in cardiac anaesthesia.

Diagnosis, pathophysiology and preventive strategies for cardiac surgery-associated acute kidney injury: a narrative review

Acute kidney injury (AKI) is a common and serious complication of cardiac surgery and is associated with increased mortality and morbidity, accompanied by a substantial economic burden. The pathogenesis of cardiac surgery-associated acute kidney injury (CSA-AKI) is multifactorial and complex, with a variety of pathophysiological theories. In addition to the existing diagnostic criteria, the exploration and validation of biomarkers is the focus of research in the field of CSA-AKI diagnosis. Prevention remains the key to the management of CSA-AKI, and common strategies include maintenance of renal perfusion, individualized blood pressure targets, balanced fluid management, goal-directed oxygen delivery, and avoidance of nephrotoxins. This article reviews the pathogenesis, definition and diagnosis, and pharmacological and nonpharmacological prevention strategies of AKI in cardiac surgical patients.