Comparison of the effects of albumin 5%, hydroxyethyl starch 130/0.4 6%, and Ringer's lactate on blood loss and coagulation after cardiac surgery

Predictive factors of postoperative complications related to free flap reconstruction in head and neck cancer patients admitted to intensive care unit: a retrospective cohort study

BACKGROUND

The epidemiology and risk factors for postoperative complications related to free flap reconstruction in head and neck cancer patients admitted to the Intensive Care Unit (ICU) are unknown.

METHODS

We performed a retrospective cohort study of patients with free flap reconstruction of head and neck cancer between September 2015 and April 2023 admitted to the ICU of Beijing Tongren Hospital. The univariate and multivariate analyses were used to explore the risk factors for postoperative complications related to free flap reconstruction admitted to ICU, including flap necrosis, bleeding, fistula, and infection.

RESULTS

A total of 239 patients were included in this study, and 38 (15.9%) patients had postoperative complications related to free flap reconstruction. The median length of ICU stay was 1 day (interquartile range, 1-2 days). Multivariate analysis found that low BMI (P < 0.001), high postoperative CRP (P = 0.005), low hemoglobin (P = 0.012), and inadequate fluid intake (P < 0.05) were independent risk factors for complications.

CONCLUSIONS

Postoperative complications related to free flap reconstruction were common in this ICU population. Careful fluid management and monitoring of CRP and hemoglobin levels may reduce complications.

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.

Perioperative fluid management for adult cardiac surgery: network meta-analysis pooling on twenty randomised controlled trials

BACKGROUND

The aim of this study was to evaluate colloids and crystalloids used in perioperative fluid therapy for cardiac surgery patients to further investigate the optimal management strategies of different solutions.

METHOD

RCTs about adult surgical patients allocated to receive perioperative fluid therapy for electronic databases, including Ovid MEDLINE, EMBase, and Cochrane Central Register of Controlled Trials, were searched up to February 15, 2023.

RESULTS

None of the results based on network comparisons, including mortality, transfuse PLA, postoperative chest tube output over the first 24 h following surgery, and length of hospital stay, were statistically significant. Due to the small number of included studies, the results, including acute kidney injury, serum creatinine, serum microglobulin, and blood urea nitrogen, are from the direct comparison. For transfusion of RBCs, significant differences were observed in the comparisons of 3% gelatine vs. 6% HES 200/0.5, 4% albumin vs. 5% albumin, 4% gelatine vs. 5% albumin, 5% albumin vs. 6% HES 200/0.5, and 6% HES 130/0.4 vs. 6% HES 200/0.5. In transfusion of FFP, significant differences were observed in comparisons of 3% gelatine vs. 4% gelatine, 3% gelatine vs. 6% HES 200/0.5, 5% albumin vs. 6% HES 200/0.5, 4% gelatine vs. 5% albumin, 4% gelatine vs. 6% HES 200/0.4, and 6% HES 130/0.4 vs. 6% HES 200/0.5. For urinary output at 24 h after surgery, the results are deposited in the main text.

CONCLUSION

This study showed that 3% gelatin and 5% albumin can reduce the transfuse RBC and FFP. In addition, the use of hypertonic saline solution can increase urine output, and 5% albumin and 6% HES can shorten the length of ICU stay. However, none of the perioperative fluids showed an objective advantage in various outcomes, including mortality, transfuse PLA, postoperative chest tube output over the first 24 h following surgery, and length of hospital stay. The reliable and sufficient evidences on the injury of the kidney, including acute kidney injury, serum creatinine, serum microglobulin, and blood urea nitrogen, was still lacking. In general, perioperative fluids had advantages and disadvantages, and there were no evidences to support the recommendation of the optimal perioperative fluid for cardiac 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.

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.

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.

Goal-directed Perioperative Albumin Substitution Versus Standard of Care to Reduce Postoperative Complications: A Randomized Clinical Trial (SuperAdd Trial)

OBJECTIVE

To investigate whether goal-directed albumin substitution during surgery and postanesthesia care to maintain a serum albumin concentration >30 g/L can reduce postoperative complications.

BACKGROUND

Hypoalbuminemia is associated with numerous postoperative complications. Since albumin has important physiological functions, substitution of patients with hypoalbuminemia is worth considering.

METHODS

We conducted a single-center, randomized, controlled, outcome assessor-blinded clinical trial in adult patients, American Society of Anesthesiologists physical status classification 3 to 4 or undergoing high-risk surgery. Patients, whose serum albumin concentration dropped <30 g/L were randomly assigned to goal-directed albumin substitution maintaining serum concentration >30 g/L or to standard care until discharge from the postanesthesia intermediate care unit. Standard of care allowed albumin substitution in hemodynamic instable patients with serum concentration <20 g/L, only. Primary outcome was the incidence of postoperative complications ≥2 according to the Clavien-Dindo Classification in at least 1 of 9 domains (pulmonary, infectious, cardiovascular, neurological, renal, gastrointestinal, wound, pain, and hematological) until postoperative day 15.

RESULTS

Of 2509 included patients, 600 (23.9%) developed serum albumin concentrations <30 g/L. Human albumin 60 g (40-80 g) was substituted to 299 (99.7%) patients in the intervention group and to 54 (18.0%) in the standard care group. At least 1 postoperative complication classified as Clavien-Dindo Classification ≥2 occurred in 254 of 300 patients (84.7%) in the intervention group and in 262 of 300 (87.3%) in the standard treatment group (risk difference -2.7%, 95% CI, -8.3% to 2.9%).

CONCLUSION

Maintaining serum albumin concentration of >30 g/L perioperatively cannot generally be recommended in high-risk noncardiac surgery patients.

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.

Human Albumin Infusion in Critically Ill and Perioperative Patients: Narrative Rapid Review of Meta-Analyses from the Last Five Years

BACKGROUND

Human albumin, a vital plasma protein with diverse molecular properties, has garnered interest for its therapeutic potential in various diseases, including critical illnesses. However, the efficacy of albumin infusion in critical care and its associated complications remains controversial. To address this, a review of recent meta-analyses was conducted to summarize the evidence pertaining to albumin use in critical illness.

METHODS

Adhering to the rapid review approach, designed to provide a concise synthesis of existing evidence within a short timeframe, relevant meta-analyses published in the last five years were identified and analyzed. PubMed, Embase, and Cochrane databases of systematic reviews were searched using pre-defined search terms. Eligible studies included meta-analyses examining the association between albumin infusion and outcomes in critically ill and perioperative patients.

RESULTS

Twelve meta-analyses were included in the review, covering diverse critical illnesses and perioperative scenarios such as sepsis, cardiothoracic surgery, and acute brain injury. The analyses revealed varying levels of evidence for the effects of albumin use on different outcomes, ranging from no significant associations to suggestive and convincing.

CONCLUSIONS

Albumin infusion stabilizes hemodynamic resuscitation endpoints, improves diuretic resistance, and has the potential to prevent hypotensive episodes during mechanical ventilation in hypoalbuminemic patients and improve the survival of patients with septic shock. However, caution is warranted due to the methodological limitations of the included studies. Further high-quality research is needed to validate these findings and inform clinical decision-making regarding albumin use in critical care.

A Critical Reassessment of the Kidney Risk Caused by Tetrastarch Products in the Perioperative and Intensive Care Environments

Purpose: To reassess the results of former meta-analyses focusing on the relationship between novel HES preparations (130/0.4 and 130/0.42) and acute kidney injury. Previous meta-analyses are based on studies referring to partially or fully unpublished data or data from abstracts only. Methods: The studies included in the former meta-analyses were scrutinized by the authors independently. We completed a critical analysis of the literature, including the strengths, weaknesses and modifiers of the studies when assessing products, formulations and outcomes. Results: Both the published large studies and meta-analyses show significant bias in the context of the deleterious effect of 6% 130/0.4-0.42 HES. Without (1) detailed hemodynamic data, (2) the exclusion of other nephrotoxic events and (3) a properly performed evaluation of the dose-effect relationship, the AKI-inducing property of 6% HES 130/0.4 or 0.42 should not be considered as evidence. The administration of HES is safe and effective if the recommended dose is respected. Conclusions: Our review suggests that there is questionable evidence for the deteriorating renal effect of these products. Further well-designed, randomized and controlled trials are needed. Additionally, conclusions formulated for resource-rich environments should not be extended to more resource-scarce environments without proper qualifiers provided.

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.

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.

[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.

Utility of 6% hydroxyethyl starch 130/0.4 in oral cancer surgeries with a duration of over 6 hours: A retrospective case-control study

To evaluate the utility of 6% hydroxyethyl starch (HES) 130/0.4 in oral cancer surgeries with durations over 6 hours. Using a case-control study design, the investigators enrolled patients who underwent oral cancer surgery involving osteotomy or manipulation near the major blood vessels at the Department of Orofacial Surgery in our hospital between 2017 and 2020. The predictor variable was 6% HES130/0.4. Outcomes included in-out balance and other postoperative parameters pertaining to circulatory maintenance (blood loss, urine volume, infusion volume, blood transfusion volume, albumin dose, hemoglobin levels, blood albumin levels, and doses of vasopressors used to maintain blood pressure), as well as pre- and postoperative renal function, pH, bicarbonate levels, and base excess. Changes in renal function were evaluated by assessing blood urea nitrogen and creatinine levels before surgery and at 1 and 7 days postoperatively. The Mann-Whitney U test was used for between-group comparisons, and Student t test was used for intragroup comparisons. The statistical significance was set at P < .05. A total of 65 patients underwent oral cancer surgery with a duration over 6 hours during the study period. The administration of 6% HES130/0.4 at 22.1 ± 7.5 mL/kg/day did not increase blood loss or the blood transfusion volume. Moreover, patients who were administered 6% HES130/0.4 had a significantly larger mean urine volume and infusion volume than those who were not administered 6% HES130/0.4. The infusion therapy could maintain the urine volume and did not worsen renal function. The results of this study showed that administration of 6% HES130/0.4 at a dose lower than 25 mL/kg in patients undergoing oral cancer surgery over 6 hours was effective for circulation maintenance but did not increase the intraoperative blood loss or transfusion volume. This treatment did not cause any dilutional metabolic acidosis or renal dysfunction.

Albumin effect on hemorheological parameters in patients with liver transplant

BACKGROUND

Liver transplantation is a life-saving treatment in end-stage liver failure. Hemorheological features as blood fluidity and red blood cell aggregation may alter effective tissue perfusion, graft function and hemodynamic variables.

OBJECTIVE

The aim of the study is to investigate effect of albumin infusion on red blood cell deformability and aggregation, blood viscosity and hemodynamics in liver transplant patients.

METHODS

Seventeen live or cadaveric donors were included in this prospective study. Hemorheological and hemodynamic measurements were performed in order to evaluate the effects of albumin infusion in perioperative period.

RESULTS

Erythrocyte aggregation was significantly reduced 90 minutes after albumin infusion (p < 0.01). Mean blood viscosity revealed significant decrease at 20 rpm and 50 rpm after 90 minutes of albumin infusion (p < 0.05). Plasma viscosity decreased significantly compared to the value before albumin infusion at 20 rpm (p < 0.05). Albumin replacement improved hemodynamic variables in patients with low blood pressure and cardiac index measurements (p > 0.05).

CONCLUSIONS

Human albumin infusion led to decrease in whole blood and plasma viscosities, red blood cell aggregation and induced blood pressure and cardiac index elevation in perioperative liver transplant patients. Determination of hemodynamic and hemorheological effects of human albumin replacement in various patient populations may serve beneficial clinical data.

A retrospective comparison of albumin versus mannitol priming fluid with relation to postoperative atrial fibrillation

BACKGROUND AND AIM OF THE STUDY

Postoperative atrial fibrillation (POAF) is a common complication following cardiac surgery which can result in increased mortality and increased healthcare costs. During Hurricane Maria (2017), a nationwide shortage of mannitol occurred, and our institution switched to the utilization of albumin as a priming fluid solution. We observed decreased rates of POAF during that time and began alternating albumin and mannitol priming fluid solutions. We hypothesized this observation may be from altered perinexal conduction from albumin utilization.

METHODS

A retrospective chart review of all patients from January 2020 through December 2020 who underwent cardiac surgery was performed, to determine if albumin was associated with reduced POAF rates. Two hundred and thirteen patients were identified and 4 were excluded. Two hundred and nine patients (110 albumin priming fluid and 99 mannitol priming fluid) were included in our final analysis.

RESULTS

Analysis was performed for all patients with POAF and in patients with new-onset AF (without a history of prior AF) after surgery. POAF rates showed no statistically significant difference between cohorts. For all patients, POAF occurred in 43% of the albumin subgroup and 47% of the mannitol subgroup (p = .53) and for patients with new-onset AF, POAF occurred in 35% of the albumin subgroup versus 42% of the mannitol subgroup (p = .36). Logistic regression revealed that age, ejection fraction and cardiopulmonary bypass time was associated with POAF, in our cohort.

CONCLUSIONS

The use of albumin compared to mannitol as priming fluid solutions was not associated with statistically significant reductions in POAF rate, in our population.

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

IMPORTANCE

In cardiac surgery, albumin solution may maintain hemodynamics better than crystalloids and reduce the decrease in platelet count and excessive fluid balance, but randomized trials are needed to compare the effectiveness of these approaches in reducing surgical complications.

OBJECTIVE

To assess whether 4% albumin solution compared with Ringer acetate as cardiopulmonary bypass prime and perioperative intravenous volume replacement solution reduces the incidence of major perioperative and postoperative complications in patients undergoing cardiac surgery.

DESIGN, SETTING, AND PARTICIPANTS

A randomized, double-blind, single-center clinical trial in a tertiary university hospital during 2017-2020 with 90-day follow-up postoperatively involving patients undergoing on-pump coronary artery bypass grafting; aortic, mitral, or tricuspid valve surgery; ascending aorta surgery without hypothermic circulatory arrest; and/or the maze procedure were randomly assigned to 2 study groups (last follow-up was April 13, 2020).

INTERVENTIONS

The patients received in a 1:1 ratio either 4% albumin solution (n = 693) or Ringer acetate solution (n = 693) as cardiopulmonary bypass priming and intravenous volume replacement intraoperatively and up to 24 hours postoperatively.

MAIN OUTCOMES AND MEASURES

The primary outcome was the number of patients with at least 1 major adverse event: death, myocardial injury, acute heart failure, resternotomy, stroke, arrhythmia, bleeding, infection, or acute kidney injury.

RESULTS

Among 1407 patients randomized, 1386 (99%; mean age, 65.4 [SD, 9.9] years; 1091 men [79%]; 295 women [21%]) completed the trial. Patients received a median of 2150 mL (IQR, 1598-2700 mL) of study fluid in the albumin group and 3298 mL (IQR, 2669-3500 mL) in the Ringer group. The number of patients with at least 1 major adverse event was 257 of 693 patients (37.1%) in the albumin group and 234 of 693 patients (33.8%) in the Ringer group (relative risk albumin/Ringer, 1.10; 95% CI, 0.95-1.27; P = .20), an absolute difference of 3.3 percentage points (95% CI, -1.7 to 8.4). The most common serious adverse events were pulmonary embolus (11 [1.6%] in the albumin group vs 8 [1.2%] in the Ringer group), postpericardiotomy syndrome (9 [1.3%] in both groups), and pleural effusion with intensive care unit or hospital readmission (7 [1.0%] in the albumin group vs 9 [1.3%] in the Ringer group).

CONCLUSIONS AND RELEVANCE

Among patients undergoing cardiac surgery with cardiopulmonary bypass, treatment with 4% albumin solution for priming and perioperative intravenous volume replacement solution compared with Ringer acetate did not significantly reduce the risk of major adverse events over the following 90 days. These findings do not support the use of 4% albumin solution in this setting.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02560519.

Albumin use for fluid resuscitation in cardiac surgical patients: a survey of Canadian perioperative care providers

PURPOSE

To evaluate the perceptions and practices of Canadian cardiovascular anesthesiologists and intensivists towards intravenous albumin as a resuscitation fluid in patients undergoing cardiac surgery.

METHODS

We conducted a cross-sectional survey of cardiac anesthesiologists and intensivists involved in the care of cardiac surgical patients. The 22-item survey included seven open-ended questions and assessed practice patterns and attitudes towards albumin. Descriptive statistics were analyzed using counts and proportions. Qualitative data were analyzed to identify themes describing albumin use patterns in Canada.

RESULTS

A total of 133 respondents from seven provinces participated, with 83 (62%) using albumin perioperatively. The majority of respondents (77%) felt a low fluid balance in cardiac surgical patients was important, and that supplementing crystalloids with albumin was helpful for this objective (67%). There was poor agreement among survey respondents regarding the role of albumin for faster vasopressor weaning or intensive care discharge, and ≥ 90% did not feel albumin reduced mortality, renal injury, or coagulopathy. Nevertheless, cardiac surgical patients were identified as a distinct population where albumin may help to minimize fluid balance. There was an acknowledged paucity of formal evidence supporting possible benefits. Fewer than 10% of respondents could identify institutional or national guidelines for albumin use. A lack of evidence supporting albumin use in cardiac surgical patients, especially those at highest risk of complications, was a frequently identified concern.

CONCLUSIONS

The majority of Canadian anesthesiologists and intensivists (62%) use albumin in cardiac surgical patients. There is clinical equipoise regarding its utility, and an acknowledged need for higher quality evidence to guide practice.

Evaluation of the effects of three designs of oxygenators with integrated filters on clinical and haematological outcomes at an Australasian cardiothoracic unit

INTRODUCTION

Cardiopulmonary bypass (CPB) machines have oxygenators with integrated filters and unique biocompatible coatings to combat systemic inflammatory response syndrome (SIRS) and mitigate coagulopathy. Contemporary oxygenators have undergone comparative studies; however, our study aimed to identify the most appropriate oxygenator for our regional Cardiothoracic unit in Australasia.

METHODS

A prospective audit consecutively recruited one-hundred and fifty patients undergoing cardiac surgery at Waikato Hospital, New Zealand between the periods of 29th January 2018 and 31st July 2018. Fifty patients were recruited for each oxygenator arm: Sorin INSPIRE' (Group-S); Terumo CAPIOX'FX (Group-T); and Medtronic Affinity Fusion' (Group-M). The clinical outcomes were transfusions, chest drain output, reoperation and length of hospital stay (LOHS). Routine blood testing protocol included: haemoglobin, protein, albumin, white cell count (WCC), C-reactive protein (CRP), platelet count and coagulations tests including international normalized ratio (INR).

RESULTS

Comparing Groups S, T and M there was no statistical difference in chest drain output (650 vs. 500 vs. 595 ml respectively, p = 0.45), transfusions (61 vs. 117 vs. 70 units, p = 0.67), reoperation (6 vs. 8 vs. 12%, p = 0.99) and LOHS (median 7.4 vs. 7.6 vs. 9.5 days, p = 0.42). Group-T had fewer SIRS cases but similar increase in CRP (p = 0.12) and WCC (p = 0.35). Group-M had a significant rise in post-op INR (p = 0.005) but no associated increase in chest drain output (p = 0.62). Group-S and -M required more 4%-albumin and Group-T had more transfusions. Only fresh frozen plasma (FFP) and red blood cell (RBC) transfusion had a significant relationship with LOHS (p < 0.05).

CONCLUSION

Biochemically, there was slight difference among the oxygenators which did not translate into clinical difference in outcomes. The oxygenator design and perfusionist choice aided in our decision-making process.

A randomised controlled trial of succinylated gelatin (4%) fluid on urinary acute kidney injury biomarkers in cardiac surgical patients

Background

Fluid resuscitation is frequently required for cardiac surgical patients admitted to the intensive care unit. The ideal fluid of choice in regard to efficacy and safety remains uncertain. Compared with crystalloid fluid, colloid fluid may result in less positive fluid balance. However, some synthetic colloids are associated with increased risk of acute kidney injury (AKI). This study compared the effects of succinylated gelatin (4%) (GEL) with compound sodium lactate (CSL) on urinary AKI biomarkers in patients after cardiac surgery.

Methods

Cardiac surgical patients who required an intravenous fluid bolus of at least 500 mL postoperatively were randomly allocated to receive GEL or CSL as the resuscitation fluid of choice for the subsequent 24 h. Primary outcomes were serial urinary neutrophil gelatinase-associated lipocalin (NGAL) and cystatin C concentrations measured at baseline, 1 h, 5 h and 24 h after enrolment, with higher concentrations indicating greater kidney injury. Secondary biomarker outcomes included urinary clusterin, α1-microglobulin and F₂-isoprostanes concentrations. Differences in change of biomarker concentration between the two groups over time were compared with mixed-effects regression models. Statistical significance was set at P < 0.05.

Results

Forty cardiac surgical patients (n = 20 per group) with similar baseline characteristics were included. There was no significant difference in the median volume of fluid boluses administered over 24 h between the GEL (1250 mL, Q1–Q3 500–1750) and CSL group (1000 mL, Q1–Q3 500–1375) (P = 0.42). There was a significantly greater increase in urinary cystatin C (P < 0.001), clusterin (P < 0.001), α1-microglobulin (P < 0.001) and F₂-isoprostanes (P = 0.020) concentrations over time in the GEL group, compared to the CSL group. Change in urinary NGAL concentration (P = 0.68) over time was not significantly different between the groups. The results were not modified by adjustment for either urinary osmolality or EuroSCORE II predicted risk of mortality.

Conclusions

This preliminary randomised controlled trial showed that use of succinylated gelatin (4%) for fluid resuscitation after cardiac surgery was associated with increased biomarker concentrations of renal tubular injury and dysfunction, compared to crystalloid fluid. These results generate concern that use of intravenous gelatin fluid may contribute to clinically relevant postoperative AKI.

Trial registration ANZCTR.org.au, ACTRN12617001461381. Registered on 16th October, 2017, http://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=373619&isReview=true.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40635-021-00412-9.

The comparison of albumin and 6% hydroxyethyl starches (130/0.4) in cardiac surgery: a meta-analysis of randomized controlled clinical trials

Background

Fluid administration is a key tool in the maintenance of normovolemia in patients with cardiac surgery. The trials that evaluated the safety of 6% hydroxyethyl starch (HES) 130/0.4 in cardiac surgical patients were inconsistent. It is necessary to compare the efficacy and safety of albumin and 6% HES (130/0.4).

Method

We searched for the randomized controlled clinical trials that compared human albumin with 6% HES (130/0.4) in cardiac surgery in PubMed, Cochrane, and Embase.

Results

Ten studies involved a total of 1567 patients were included in our meta-analysis. For the efficiency, there was no difference in total volume of infusion between compared groups [P = 0.64, Fixed Effect Model (FEM): standardized mean difference (SMD) = 0.04, 95% confidence interval (CI) (− 0.12, 0.20)]. As for safety, the albumin show more risk than hydroxyethyl starch 130/0.4 in blood loss [P = 0.02, FEM: SMD: 0.22, 95% CI (0.03, 0.41)]. There was no difference in the frequency of transfusions (P = 0.20, RR = 1.11; 95% CI (0.95, 1.27)) between the two groups. No difference was observed for the days in intensive care unit [P = 0.05, FEM: SMD = − 0.18, 95% CI (− 0.36, 0.00)], and the days in hospital [P = 0.32, FEM: SMD = − 0.11, 95% CI (− 0.32, 0.10)]. Furthermore, both the incidence of AKI, RRT, and mortality were comparable in the two groups.

Conclusion

This study provided evidence that the 6% HES (130/0.4) might be the substitute for HA, which reduced the economic burden for patients with cardiac surgery. However, the effect of 6% HES (130/0.4) and HA on AKI still needs to be further studied.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12893-021-01340-x.

Albumin in adult cardiac surgery: a narrative review

PURPOSE

Intravascular fluids are a necessary and universal component of cardiac surgical patient care. Both crystalloids and colloids are used to maintain or restore circulating plasma volume and ensure adequate organ perfusion. In Canada, human albumin solution (5% or 25% concentration) is a colloid commonly used for this purpose. In this narrative review, we discuss albumin supply in Canada, explore the perceived advantages of albumin, and describe the clinical literature supporting and refuting albumin use over other fluids in the adult cardiac surgical population.

SOURCE

We conducted a targeted search of PubMed, Embase, Medline, Web of Science, ProQuest Dissertations and Theses Global, the Cochrane Central Register of Controlled trials, and the Cochrane Database of Systematic Reviews. Search terms included albumin, colloid, cardiac surgery, bleeding, hemorrhage, transfusion, and cardiopulmonary bypass.

PRINCIPAL FINDINGS

Albumin is produced from fractionated human plasma and imported into Canada from international suppliers at a cost of approximately $21 million CAD per annum. While it is widely used in cardiac surgical patients across the country, it is approximately 30-times more expensive than equivalent doses of balanced crystalloid solutions, with wide inter-institutional variability in use and no clear association with improved outcomes. There is a general lack of high-quality evidence for the superiority of albumin over crystalloids in this patient population, and conflicting evidence regarding safety.

CONCLUSIONS

In cardiac surgical patients, albumin is widely utilized despite a lack of high- quality evidence supporting its efficacy or safety. A well-designed randomized controlled trial is needed to clarify the role of albumin in cardiac surgical patients.

Safety and efficacy of tetrastarches in surgery and trauma: a systematic review and meta-analysis of randomised controlled trials

BACKGROUND

Hydroxyethyl starch (HES) 130 is a frequently used fluid to replace intravascular losses during surgery or trauma. In the past years, several trials performed in critically ill patients have raised questions regarding the safety of this product. Our aim in this meta-analysis was to evaluate the safety and efficacy of 6% HES during surgery and in trauma.

METHODS

This systematic review and meta-analysis was registered at PROSPERO (CRD42018100379). We included 85 fully published articles from 1980 to June 2018 according to the protocol and three additional recent articles up to June 2020 in English, French, German, and Spanish reporting on prospective, randomised, and controlled clinical trials applying volume therapy with HES 130/0.4 or HES 130/0.42, including combinations with crystalloids, to patients undergoing surgery. Comparators were albumin, gelatin, and crystalloids only. A meta-analysis could not be performed for the two trauma studies as there was only one study that reported data on endpoints of interest.

RESULTS

Surgical patients treated with HES had lower postoperative serum creatinine (P<0.001) and showed no differences in renal dysfunction, renal failure, or renal replacement therapy. Although there was practically no further difference in the colloids albumin or gelatin, the use of HES improved haemodynamic stability, reduced need for vasopressors (P<0.001), and decreased length of hospital stay (P<0.001) compared with the use of crystalloids alone.

CONCLUSIONS

HES was shown to be safe and efficacious in the perioperative setting. Results of the present meta-analysis suggest that when used with adequate indication, a combination of intravenous fluid therapy with crystalloids and volume replacement with HES as colloid has clinically beneficial effects over using crystalloids only.

Albumin use in bleeding cardiac surgical patients and associated patient outcomes

PURPOSE

Albumin solution is a colloid used for resuscitation in cardiac surgical patients, but it is unclear if it offers advantages over crystalloids. We examined current clinical practice across 11 cardiac surgical centres and the association of albumin with outcomes in a cohort of bleeding cardiac surgical patients.

METHODS

This was a post hoc analysis of data from the Effect of Fibrinogen Concentrate vs Cryoprecipitate on Blood Component Transfusion After Cardiac Surgery (FIBRES) trial. Multivariable regression models adjusted for demographic and surgical characteristics were used to examine predictors of early albumin administration (within the initial 24 perioperative hours), late albumin administration (from 24 hr to seven days after cardiopulmonary bypass), and the association of albumin use with 28-day acute kidney injury, mortality, and length of hospital and intensive care unit (ICU) stay.

RESULTS

Of the 735 patients included, 525 (71%) received albumin, ranging from 4.8% to 97.4% of patients across institutions, with 475 (64.6%) receiving albumin early (5% or 25% solution). In the adjusted models, female sex and preoperative hospital admission were associated with early use, while heart failure, female sex, bleeding severity, older age, and prior albumin use were predictors of later administration. Early albumin use was not associated with differences in acute kidney injury (adjusted odds ratio [aOR] 1.77; 95% confidence interval [CI], 0.96 to 3.27; P = 0.07), mortality (aOR 1.66; 95% CI, 0.99 to 2.78; P = 0.05), or length of ICU stay (P = 0.11) or hospital stay (P = 0.67).

CONCLUSIONS

Albumin use is common but highly variable within and across sites. Albumin use was not associated with improved outcomes. High quality randomized controlled trials should clarify its role in cardiac surgical patients.

Comparison of the Effects of Ringer's Lactate and 6% Hydroxyethyl Starch 130/0.4 on Blood Loss and Need for Blood Transfusion After Off-Pump Coronary Artery Bypass Graft Cardiac Surgery

Background Infusion of crystalloids fluid replacement therapy tends to cause a greater expansion of intravascular volume. However, colloids can affect blood coagulation leading to greater blood loss and transfusion requirements. This study compared the intraoperative and postoperative blood loss with Ringer's lactate (RL) versus 6% hydroxyethyl starch (HES) 130/0.4 as infusion fluid during cardiac surgery. Methods Eighty adult male and female patients undergoing elective cardiac surgery were randomly assigned to receive either RL or 6% HES 130/0.4 20 ml/kg during off-pump coronary artery bypass graft (OP-CABG) surgery. Intraoperative blood loss and 24 hours postoperative chest tube drainage were the primary outcomes. Simultaneously, blood transfusions, thromboelastometry variables, total fluid requirement, renal function, and intensive care unit (ICU) stay were assessed. Results The intraoperative blood loss was similar (p > 0.05) with HES (716 ml) and RL (658 ml). Postoperative chest tube drainage was higher (p < 0.05) with HES (513 ml) as against RL (449 ml). The total fluid requirement was higher in the RL group. Alteration of thromboelastometry variables, renal function, and ICU stay was comparable between the two groups. Postoperative chest tube drainage was less with the use of RL during cardiac surgery. A lesser total fluid requirement in the HES group did not lead to any improvement in renal function and the length of ICU stay. Conclusions Crystalloids (RL) provide similar outcomes to HES and can be used as substitutes to colloids during cardiac surgery. However, further large-scale multicenter studies with varied indications can be suggested to substantiate the equivalence of crystalloids to colloids in perioperative management.

Hydroxyethyl starch 130/0.4 for volume replacement therapy in surgical patients: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The safety of perioperative intravenous hydroxyethyl starch (HES) products, specifically HES 130/0.4, continues to be the source of much debate. The aim of this meta-analysis was to update the existing evidence and gain further insight into the clinical effects of HES 130/0.4 on postoperative outcomes for volume replacement therapy in surgical patients.

METHODS

MEDLINE, EMBASE, and Cochrane Library databases were searched from inception to March 2020 for relevant randomized controlled trials (RCTs) on perioperative use of HES 130/0.4 in adult surgical patients. The primary outcome was postoperative mortality and secondary outcomes were the incidence of acute kidney injury (AKI) and requirement for renal replacement therapy (RRT). The analysis was performed using the random-effects method and the risk ratio (RR) with a 95% confidence interval (CI). We performed the risk-of-bias assessment of eligible studies and assessed the overall quality of evidence for each outcome.

RESULTS

Twenty-five RCTs with 4111 participants were finally included. There were no statistical differences between HES 130/0.4 and other fluids in mortality at 30 days (RR 1.28, 95% CI 0.88 to 1.86, p = 0.20), the incidence of AKI (RR 1.23, 95% CI 0.99 to 1.53, p = 0.07), or requirement for RRT (RR 0.75, 95% CI 0.37 to 1.53, p = 0.43). Overall, there was a moderate certainty of evidence for all the outcomes. There was no subgroup difference related to the type of surgery (p = 0.17) in the incidence of AKI. As for the type of comparator fluids, however, there was a trend that was not statistically significant (p = 0.06) towards the increased incidence of AKI in the HES 130/0.4 group (RR 1.22, 95% CI 0.97 to 1.54) compared with the crystalloid group (RR 1.21, 95% CI 0.27 to 3.91). Subgroup analyses according to the type of surgery demonstrated consistent findings.

CONCLUSIONS

This systematic review and meta-analysis suggests that the use of HES 130/0.4 for volume replacement therapy compared with other fluids resulted in no significant difference in postoperative mortality or kidney dysfunction among surgical patients. Given the absent evidence of confirmed benefit and the potential trend of increased kidney injury, we cannot recommend the routine clinical use of HES 130/0.4 for volume replacement therapy in surgical patients from the perspective of benefit/risk profile. However, the results need to be interpreted with caution due to the limited sample size, and further well-powered RCTs are warranted.

TRIAL REGISTRATION

PROSPERO registry reference: CRD42020173058.

Albumin therapy for acute ischemic stroke: a meta-analysis

Human serum albumin has shown remarkable efficacy in rodent models of ischemic stroke, while results from relevant clinical research on albumin therapy remain controversial. We conducted a meta-analysis of published studies to quantitatively analyze the neurofunctional outcomes of patients with ischemic stroke treated with albumin. PubMed, Embase, and Cochrane Library were searched in July 2020. A total of four studies and 1611 patients were included. The aggregated results indicated that there were 635 patients with good neurological outcomes, among which 321 patients were in the albumin group (39.8%) and 314 patients in the control group (39.1%), showing no statistically significant difference between the albumin and control groups (OR = 1.04, 95% CI 0.85-1.27). The results suggest that albumin therapy at the acute stage of ischemic stroke has no beneficial effect on the long-term neurological function of patients with ischemic stroke. Considering pulmonary edema and other complications are more likely to occur in such patients after albumin infusion, the administration of albumin therapy for acute ischemic stroke should be done with utmost caution.

Perioperative Clinical Trials in AKI

To characterize current evidence and current foci of perioperative clinical trials, we systematically reviewed Medline and identified perioperative trials involving 100 or more adult patients undergoing surgery and reporting renal end points that were published in high-impact journals since 2004. We categorized the 101 trials identified based on the nature of the intervention and summarized major trial findings from the five categories most applicable to perioperative management of patients. Trials that targeted ischemia suggested that increasing perioperative renal oxygen delivery with inotropes or blood transfusion does not reliably mitigate acute kidney injury (AKI), although goal-directed therapy with hemodynamic monitors appeared beneficial in some trials. Trials that have targeted inflammation or oxidative stress, including studies of nonsteroidal anti-inflammatory drugs, steroids, N-acetylcysteine, and sodium bicarbonate, have not shown renal benefits, and high-dose perioperative statin treatment increased AKI in some patient groups in two large trials. Balanced crystalloid intravenous fluids appear safer than saline, and crystalloids appear safer than colloids. Liberal compared with restrictive fluid administration reduced AKI in a recent large trial in open abdominal surgery. Remote ischemic preconditioning, although effective in several smaller trials, failed to reduce AKI in two larger trials. The translation of promising preclinical therapies to patients undergoing surgery remains poor, and most interventions that reduced perioperative AKI compared novel surgical management techniques or existing processes of care rather than novel pharmacologic interventions.

Intravenous Fluid Administration and the Coagulation System

Intravenous fluid administration in veterinary patients can alter coagulation function by several mechanisms. Both crystalloid and colloid fluids cause hemodilution, reducing platelet count and plasma coagulation protein concentrations. Hemodilution is associated with a hypercoagulable effect at low dilutions and a hypocoagulable effect at higher dilutions. Composition of crystalloid fluids likely has a minor effect, primarily dependent on fluid ion composition. Hypertonic crystalloids may also cause hypocoagulability. Colloids, both synthetic and natural, can cause hypocoagulability by several mechanisms beyond the effects of hemodilution. These include impaired platelet function, decreased plasma coagulation factor activity, impaired fibrin formation and crosslinking, and accelerated fibrinolysis. The vast majority of the veterinary literature investigates the hypocoagulable effects of hydroxyethyl starch-containing fluids using in vitro, experimental, and clinical studies. However, results are inconsistent, likely due to the varying doses and physicochemical properties of the specific fluid products across studies. In addition, some evidence exists for hypocoagulable effects of gelatin and albumin solutions. There is also evidence that these colloids increase the risk of clinical bleeding in people. Limitations of the veterinary evidence for the hypocoagulable effects of colloid fluids include a predominance of in vitro studies and in vivo studies using healthy subjects, which exclude the interaction of the effects of illness. Therefore, clinical relevance of these effects, especially for low-molecular-weight hydroxyethyl starch, is unknown. Firm recommendations about the most appropriate fluid to use in clinical scenarios cannot be made, although it is prudent to limit the dose of synthetic colloid in at-risk patients. Clinicians should closely monitor relevant coagulation assays and for evidence of hemorrhage in at-risk patients receiving any type of fluid therapy, especially in large volumes.

Effect of Goal-Directed Crystalloid versus Colloid Administration on Perioperative Hemostasis in Partial Hepatectomy: A Randomized, Controlled Trial

The use of colloids may impair hemostatic capacity. However, it remains unclear whether this also holds true when colloids are administered in a goal-directed manner. The aim of the present study was to assess the effect of goal-directed fluid management with 6% hydroxyethyl starch 130/0.4 on hemostasis compared to lactated Ringer’s solution in patients undergoing partial hepatectomy. We included 50 patients in this prospective, randomized, controlled trial. According to randomization, patients received boluses of either hydroxyethyl starch or lactated Ringer’s solution within the scope of goal-directed fluid management. Minimum perioperative FIBTEM maximum clot firmness (MCF) served as the primary outcome parameter. Secondary outcome parameters included fibrinogen levels and estimated blood loss. In the hydroxyethyl starch (HES) group the minimum FIBTEM MCF value was significantly lower (effect size −6 mm, 95% CI −10 to −3, p < 0.001) in comparison to the lactated Ringer’s solution (RL) group. These results returned to normal within 24 h. We observed no difference in plasma fibrinogen levels (RL 3.08 ± 0.37 g L⁻¹ vs HES 2.65 ± 0.64 g L⁻¹, p = 0.18) or the amount of blood loss between the two groups (RL 470 ± 299 mL vs HES 604 ± 351 mL, p = 0.18). We showed that goal-directed use of HES impairs fibrin polymerization in a dose-dependent manner when compared with RL. Results returned to normal on the first postoperative day without administration of procoagulant drugs and no differences in blood loss were observed.

Hydroxyethylstarch revisited for acute brain injury treatment

Infusion of the colloid hydroxyethylstarch has been used for volume substitution to maintain hemodynamics and microcirculation after e.g., severe blood loss. In the last decade it was revealed that hydroxyethylstarch can aggravate acute kidney injury, especially in septic patients. Because of the serious risk for critically ill patients, the administration of hydroxyethylstarch was restricted for clinical use. Animal studies and recently published in vitro experiments showed that hydroxyethylstarch might exert protective effects on the blood-brain barrier. Since the prevention of blood-brain barrier disruption was shown to go along with the reduction of brain damage after several kinds of insults, we revisit the topic hydroxyethylstarch and discuss a possible niche for the application of hydroxyethylstarch in acute brain injury treatment.

Gelatin and the risk of bleeding after cardiac surgery

BACKGROUND

Gelatins has been used in cardiac surgery because of their ability to preserve intravascular volume better than crystalloids. Unfortunately, gelatin has been associated with impaired coagulation and hemostasis, that may cause increased bleeding. We investigated whether the administration of gelatin increases postoperative bleeding after cardiac surgery.

METHODS

Retrospective, observational single-center cohort study in the intensive care unit of a tertiary teaching hospital. Postoperative bleeding, chest tube drainage volume and consumption of blood products were compared between groups.

RESULTS

Cohort included 3067 consecutive patients who underwent cardiac surgery. First 1698 patients received gelatin (gelatin group), and 1369 patients did not (crystalloid group). The characteristics of the patients in the gelatin and crystalloid groups were comparable. Postoperative chest tube drainage was 18% (95% CI 11%-20%) greater during the first 12 hours (P < .001) and 15% (95% CI 7%-17%) greater during the first 24 hours (P < .001) in the gelatin group compared to the crystalloid group. Severe and massive postoperative bleeding was more common in the gelatin group compared to the crystalloid group (21% vs 16%, P < .001). Patients in the gelatin group received red blood cells (40% vs 20%, P < .001) and platelets (12% vs 8%, P < .001) more frequently than patients in the crystalloid group. However, the number of administered fresh-frozen plasma transfusions did not differ between the groups.

CONCLUSION

Gelatin may increase postoperative bleeding and the need for blood product transfusions after cardiac surgery.

Impact of 6% balanced hydroxyethyl starch following cardiopulmonary bypass on renal function: a retrospective study

Background

We aimed to evaluate the effect of limited volume of hydroxyethyl starch (HES) administration on postoperative renal function in patients undergoing cardiac surgery under cardiopulmonary bypass (CPB).

Methods

One thousand six hundred fifty-seven patients undergoing cardiac surgery under CPB over two years were included. The patients were divided according to the amount of HES administrated during the first 2 days post-surgery; moderate dose HES (≥20 ml/kg) versus low dose HES (< 20 ml/kg). Outcomes were compared by using inverse probability weighting.

Results

Incidence of acute kidney injury (AKI) was higher in the moderate HES group (p = .02). However, new renal replacement therapy (RRT) (P = .30) and early mortality (p = .97) was similar between the groups. When adjusted, the moderate HES use was associated with AKI (OR, 1.66; 95% CI, 1.12–2.44; p = .01), but did not increase the risk of new RRT (OR, 1.27; 95% CI, 0.71–2.18; p = .40) or early mortality (HR, 0.73; 95% CI, 0.29–1.81; p = .50).

Conclusions

The moderate dose administration of HES (≥20 ml/kg) in the postoperative period following cardiac surgery might be associated with the risk of AKI. However, it was not associated with serious adverse outcomes such as new RRT or mortality. Further randomized controlled studies are needed to validate study results.

Substitution of perioperative albumin deficiency disorders (SuperAdd) in adults undergoing vascular, abdominal, trauma, or orthopedic surgery: protocol for a randomized controlled trial

Background

Hypalbuminemia is associated with numerous postoperative complications, so a perioperative albumin substitution is often considered. The objective of SuperAdd is to investigate whether substitution of human albumin, aiming to maintain a serum concentration > 30 g/l, can reduce postoperative complications in normovolemic surgical patients in comparison with standard care.

Methods/design

SuperAdd is a single-center, prospective, randomized, outcome-assessor blinded, patient blinded controlled trial. The primary outcome is the frequency of postoperative complications identified using the Postoperative Morbidity Survey graded ≥ 2 according to the Clavien-Dindo Score. Adult patients at risk to develop hypalbuminemia, i.e., ASA III or IV or high-risk surgery, are recruited after written informed consent was obtained. The albumin concentration is assessed before the induction of anesthesia and every 3 h until admission to the postanesthesia care unit. If albumin concentrations drop below 30 g/l, patients are randomly allocated to the control or the treatment group. The study intervention is a goal-directed human albumin substitution aimed at a concentration > 30 g/l during surgery and postanesthesia care unit stay. The patients in the control group are treated according to standard clinical care. Postoperative visits are to be performed on days 1, 3, 5, 8, and 15, as well as by telephone 6 months after surgery.

Discussion

SuperAdd is the first clinical trial in a surgical population investigating the effect of a goal-directed albumin substitution aiming at a serum level > 30 g/l. The nonrestrictive selection of patients guarantees that the patients without albumin screening will most likely not develop hypalbuminemia, thus ensuring generalizability of the study results.

Trial registration

EudraCT 2016-001313-24. Registered on 5 September 2016. Clinical Trials NCT03167645. Registered on 18 October 2016 and has the Universal Trial Number (UTN) U1111-1181-2625.

Effect and safety of 4% albumin in the treatment of cardiac surgery patients: study protocol for the randomized, double-blind, clinical ALBICS (ALBumin In Cardiac Surgery) trial

Background

In cardiac surgery with cardiopulmonary bypass (CPB), large amounts of fluids are administered. CPB priming with crystalloid solution causes marked hemodilution and fluid extravasation. Colloid solutions may reduce fluid overload because they have a better volume expansion effect than crystalloids. The European Medicines Agency does not recommend the use of hydroxyethyl starch solutions (HES) due to harmful renal effects. Albumin solution does not impair blood coagulation but the findings on kidney function are conflicting. On the other hand, albumin may reduce endothelial glycocalyx destruction and decrease platelet count during CPB. No large randomized, double-blind, clinical trials have compared albumin solution to crystalloid solution in cardiac surgery.

Methods/design

In this single-center, double-blind, randomized controlled trial comprising 1386 adult cardiac surgery patients, 4% albumin solution will be compared to Ringer’s acetate solution in CPB priming and volume replacement up to 3200 mL during surgery and the first 24 h of intensive care unit stay. The primary efficacy outcome is the number of patients with at least one major adverse event (MAE) during 90 postoperative days (all-cause death, acute myocardial injury, acute heart failure or low output syndrome, resternotomy, stroke, major arrhythmia, major bleeding, infection compromising post-procedural rehabilitation, acute kidney injury). Secondary outcomes are total number of MAEs, incidence of major adverse cardiac events (MACE; cardiac death, acute myocardial injury, acute heart failure, arrhythmia), amount of each type of blood product transfused (red blood cells, fresh frozen plasma, platelets), total fluid balance at the end of the intervention period, total measured blood loss, development of acute kidney injury, days alive without mechanical ventilation in 90 days, days alive outside intensive care unit at 90 days, days alive at home at 90 days, and 90-day mortality.

Discussion

The findings of this study will provide new evidence regarding efficacy and safety of albumin solution in adult patients undergoing cardiac surgery with CPB.

Trial registration

EudraCT (clinicaltrialsregister.eu) 2015–002556-27 Registered 11 Nov 2016 and ClinicalTrials.gov NCT02560519. Registered 25 Sept 2015.

Effects of Dextran-70 and Albumin on Coagulation in Experimental Hemorrhage in the Guinea Pig

Background:

Dextran-70 is a more potent plasma volume expander than albumin but use has been hampered because of its antithrombotic properties. However, also albumin has antithrombotic properties and little is known about relative effects of these two colloids on coagulation in vivo when controlling for differences in efficacy as plasma volume expanders.

Aim:

Compare effects of dextran-70 and albumin on coagulation at a dose resulting in equal plasma volume expansion.

Methods:

Guinea pigs were subjected to a 25 mL/kg hemorrhage during 20 min and randomized to resuscitation with either 6% dextran-70 at a dose of 15 mL/kg or 5% albumin at a dose of 25 mL/kg (n = 14 in each group) during 30 min starting 1 h of shock. Blood samples were collected at the completion of resuscitation and at 4 h. Plasma volume was measured using ¹²⁵I-albumin and the effect on coagulation was evaluated using whole blood thrombelastography (TEG), measurement of plasma fibrinogen and von Willebrand factor (vWF) concentrations and vWF glycoprotein 1b (GP1b) A activity.

Results:

Plasma volumes after resuscitation were similar in the groups at both time points. Dextran-70 resulted in a transient prolongation of TEG clot amplification time (K) at the completion of resuscitation compared with albumin. TEG clot initiation (R) and strength (MA) did not differ between the treatments at any of the time points. Albumin reduced vWF concentrations to a larger extent than dextran at both time points, whereas no difference in vWF GP1bA activity or in plasma fibrinogen and could be detected.

Conclusion:

In equipotent doses with regard to plasma volume expansion, dextran-70 transiently prolongs clot amplification time more than albumin whereas dextran-70 reduces plasma vWF concentrations less than albumin.

Fluid Management Practices After Surgery for Congenital Heart Disease: A Worldwide Survey

OBJECTIVES

To determine common practice for fluid management after cardiac surgery for congenital heart disease among pediatric cardiac intensivists.

DESIGN

A survey consisting of 17 questions about fluid management practices after pediatric cardiac surgery. Distribution was done by email, social media, World Federation of Pediatric Intensive and Critical Care Societies website, and World Federation of Pediatric Intensive and Critical Care Societies newsletter using the electronic survey distribution and collection system Research Electronic Data Capture.

SETTING

PICUs around the world.

SUBJECTS

Pediatric intensivists managing children after surgery for congenital heart disease.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

One-hundred eight responses from 18 countries and six continents were received. The most common prescribed fluids for IV maintenance are isotonic solutions, mainly NaCl 0.9% (42%); followed by hypotonic fluids (33%) and balanced crystalloids solutions (14%). The majority of the respondents limit total fluid intake to 50% during the first 24 hours after cardiac surgery. The most frequently used fluid as first choice for resuscitation is NaCl 0.9% (44%), the second most frequent choice are colloids (27%). Furthermore, 64% of respondents switch to a second fluid for ongoing resuscitation, 76% of these choose a colloid. Albumin 5% is the most commonly used colloid (61%). Almost all respondents (96%) agree there is a need for research on this topic.

CONCLUSIONS

Our survey demonstrates great variation in fluid management practices, not only for maintenance fluids but also for volume resuscitation. Despite the lack of evidence, colloids are frequently administered. The results highlight the need for further research and evidence-based guidelines on this topic.

Postoperative Blood Loss and Coagulation Changes After Balanced 6% Hydroxyethyl Starch 130/0.4 Administration During Spine Surgery: A Retrospective Study

STUDY DESIGN

Retrospective analysis.

OBJECTIVE

The objective of this study was to investigate the effects of intraoperative balanced 6% hydroxyethyl starch (HES) 130/0.4 on postoperative blood loss and the coagulation profile.

SUMMARY OF BACKGROUND DATA

The safety of colloid versus crystalloid transfusion for bleeding and coagulation during major spine surgery remains controversial and only a few studies exist. Thus, we compared the effects of balanced 6% HES 130/0.4 and crystalloid on postoperative bleeding and coagulation.

METHODS

Patients undergoing spine surgery between February 1, 2015 and February 28, 2017 were divided into 2 groups: patients receiving intraoperative balanced 6% HES 130/0.4 and patients receiving crystalloid. We compared the postoperative bleeding volume with changes in the coagulation profile and length of hospital stay between these 2 groups. Propensity score (PS)-matching and multivariate stepwise linear regression were performed.

RESULTS

A total of 169 patients who met the inclusion criteria were analyzed. The quantity of total colloid per patient was 10-15 mL/kg. A significant difference was observed in the total intraoperative transfused crystalloid volume between the 2 groups (colloid group, 1.394.6±1.414.0 mL; crystalloid group, 2.027.3±1.114.1 mL; P<0.001). Postoperative blood loss and coagulation profile changes were not significantly different in the 60 PS-matched paired patients. Furthermore, no differences in either postoperative transfusion requirement or length of hospital stay were observed between the groups. Multivariate stepwise linear regression revealed that operation time (β=0.549; P<0.001) and intraoperative transfusion of packed red blood cells (β=0.466; P=0.003) or fresh frozen plasma (β=-0.263; P=0.041) were independently associated with postoperative blood loss. However, intraoperative colloid administration was not a predictive factor.

CONCLUSIONS

Intraoperative infusion of balanced 6% HES 130/0.4 in patients undergoing spine surgery presented clinically insignificant changes in postoperative blood loss and coagulation compared to crystalloid.

LEVEL OF EVIDENCE

Level III.

Optimal crystalloid volume ratio for blood replacement for maintaining hemodynamic stability and lung function: an experimental randomized controlled study

BACKGROUND

Crystalloids are first line in fluid resuscitation therapy, however there is a lack of evidence-based recommendations on the volume to be administered. Therefore, we aimed at comparing the systemic hemodynamic and respiratory effects of volume replacement therapy with a 1:1 ratio to the historical 1:3 ratio.

METHODS

Anesthetized, ventilated rats randomly included in 3 groups: blood withdrawal and replacement with crystalloid in 1:1 ratio (Group 1, n = 11), traditional 1:3 ratio (Group 3, n = 12) and a control group with no interventions (Group C, n = 9). Arterial blood of 5% of the total blood volume was withdrawn 7 times, and replaced stepwise with different volume rations of Ringer's acetate, according to group assignments. Airway resistance (Raw), respiratory tissue damping (G) and tissue elastance (H), mean arterial pressure (MAP) and heart rate (HR) were assessed following each step of fluid replacement with a crystalloid (CR1-CR6). Lung edema index was measured from histological samples.

RESULTS

Raw decreased in Groups 1 and 3 following CR3 (p < 0.02) without differences between the groups. H elevated in all groups (p < 0.02), with significantly higher changes in Group 3 compared to Groups C and 1 (both p = 0.03). No differences in MAP or HR were present between Groups 1 and 3. Lung edema was noted in Group 3 (p < 0.05).

CONCLUSIONS

Fluid resuscitation therapy by administering a 1:1 blood replacement ratio revealed adequate compensation capacity and physiological homeostasis similar with no lung stiffening and pulmonary edema. Therefore, considering this ratio promotes the restrictive fluid administration in the presence of continuous and occult bleeding.