Comparison of dextran and albumin on blood coagulation in patients undergoing major gynaecological surgery

Effect of Selected Crystalloid and Colloid Solutions on Coagulation Status Evaluated by Rotational Thromboelastometry and Platelet Function Analyser: An in vitro Study

Introduction

Crystalloid and colloid solutions commonly used in intensive and perioperative care can affect haemocoagulation status. This in vitro study assessed the impact of Plasma-Lyte, albunorm 5%, and Gelaspan 4% solutions on primary and secondary haemostasis using rotational thromboelastometry and platelet function analyser.

Methods

In this prospective study, we examined blood samples from 20 healthy volunteers using rotational thromboelastometry and platelet function analyser. Simultaneously, we analysed the blood samples subjected to 10% dilution using Plasma-Lyte, albunorm 5%, and Gelaspan 4% solutions.

Results

Compared to controls, Plasma-Lyte shortened EXTEM-CT (p = 0.005) and reduced FIBTEM-MCF (p = 0.017). albunorm 5% prolonged EXTEM-CFT (p = 0.001), decreased EXTEM-alpha (p < 0.001) and MCF in EXTEM, INTEM, and FIBTEM tests (p < 0.001, p = 0.038, p = 0.001, respectively), along with MCE in the PLTEM test (p < 0.001). Gelaspan 4% also prolonged EXTEM-CFT (p < 0.001), decreased EXTEM-alpha (p < 0.001) and MCF in EXTEM, INTEM, and FIBTEM tests (p < 0.001, p < 0.001, p = 0.009, respectively), along with MCE in the PLTEM test (p < 0.001). Gelaspan 4% also reduced EXTEM-CT (p = 0.021). All solution prolonged CT in PFA Col/ADP (p = 0.003 for Plasma-Lyte, p < 0.001 for albunorm and Gelaspan) and albunorm 5% also prolonged CT in Col/Epi (p = 0.003).

Conclusion

Plasma-Lyte had the least effect on secondary haemostasis, whereas albunorm 5% had the least effect among colloids. Gelaspan 4% adversely affected the propagation phase of coagulation, maximal strength and elasticity of the coagulum, and the level of functional fibrinogen. All solutions adversely affected platelet function in primary haemostasis, with Plasma-Lyte showing the least effect.

Three-dimensional bio-derived materials for biomedical applications: challenges and opportunities

Three-dimensional (3D) bio-derived materials are emerging as a promising approach to enhance wound healing therapies. These innovative materials can be tailored to meet the specific needs of various wound types and patients, facilitating the controlled release of therapeutic agents such as growth factors and antibiotics, which promote cell growth and tissue regeneration. Despite their potential, significant challenges remain in achieving optimal biocompatibility, ensuring structural integrity, and maintaining precise release mechanisms. Additionally, issues such as scalability, cost-effectiveness, and regulatory compliance pose substantial barriers to widespread use. However, recent advances in materials science and interdisciplinary research offer new opportunities to overcome these challenges. This review provides a comprehensive analysis of the current state of 3D bio-derived materials in biomedical applications, highlighting the types of materials available, their advantages and limitations, and the progress made in their design and development. It also outlines new directions for future research aimed at bridging the gap between scientific discoveries and their practical applications in injury healing strategies. The findings of this review underscore the significant potential of 3D bio-derived materials in revolutionizing wound healing and advancing personalized therapeutic approaches.

Evaluation of efficacy and safety of perioperative albumin administration in major non-cardiac surgery: a systematic review and meta-analysis of randomized controlled trials

INTRODUCTION

Studies suggested that restrictive fluid therapy during major surgery could be associated with better post-operative outcomes. The albumin uses in the perioperative period has been the subject of numerous studies with a still controversial efficacy and safety profile. This study aimed to assess the efficacy and safety of perioperative albumin use during major non-cardiac surgery.

EVIDENCE ACQUISITION

This study was registered in PROSPERO (ID: CRD42022353278). We performed an electronic search of the relevant literature from 2000 until 2023. The primary endpoint was the incidence of moderate postoperative complications (defined by a Clavien-Dindo classification grade ≥2). Secondary endpoints were intraoperative fluid balance, intraoperative blood loss, postoperative wound infection and acute kidney injury (AKI).

EVIDENCE SYNTHESIS

We identified four relevant studies involving 426 patients (213 patients in the albumin group versus 213 patients in the control group). The meta-analysis did not reveal any significant difference between both group regarding the incidence of postoperative moderate complications even after subgroup analyses based on intraoperative or postoperative albumin administration (OR=1.23, 95% CI 0.73, 2.08, P=0.44). No difference was found for intraoperative fluid balance (MD=-190.83, 95% CI -408.67, 27.02, P=0.09), intraoperative blood loss (MD=-27.54, 95% CI -225.55, 170.48, P=0.79) and postoperative wound infection (OR=1.91, 95% CI 0.98, 3.73, P=0.06). Moreover, albumin administration was not associated with a significant increase of AKI incidence (OR=2.02, 95% CI 0.90, 4.53, P=0.09).

CONCLUSIONS

Perioperative use of albumin during major non-cardiac surgery did not result in an increased incidence of moderate postoperative complications.

A novel miniaturized roller pump circuit for simulation of extracorporeal circulation

OBJECTIVES

Extracorporeal circulation induces pronounced effects on haemostasis and rheology. To study these, an ex vivo simulation model is an attractive alternative but often requires large amounts of blood. We sought to create a miniaturized roller pump circuit requiring minimal amounts of blood and to test if the circuit could be used to compare coagulation, platelet function and blood rheology between a dextran-based and a crystalloid-based priming solution.

METHODS

A miniaturized roller pump circuit requiring only 27 ml of blood was created. Blood samples from 8 cardiac surgery patients were mixed with either a dextran-based or a crystalloid-based solution and circulated for 60 min. Coagulation was assessed by rotational thromboelastometry, and platelet function by impedance aggregometry and flow cytometry, before and at 5 and 60 min of circulation.

RESULTS

A time-dependent impairment of coagulation was observed in both groups. Maximum clot firmness was lower with dextran-based than with crystalloid-based priming at 5 min (HEPTEM 37 ± 4 vs 43 ± 4 mm, P < 0.001; EXTEM 37 ± 4 vs 43 ± 4 mm, P < 0.001; FIBTEM 3 ± 2 vs 9 ± 2 mm, P < 0.001) and at 60 min (HEPTEM 29 ± 9 vs 38 ± 5 mm, P < 0.001; EXTEM 30 ± 7 vs 39 ± 5 mm, P < 0.001; FIBTEM 3 ± 2 vs 8 ± 3 mm, P = 0.002). The EXTEM clotting time was longer with dextran-based solution at 5 (109 ± 19 vs 63 ± 7 sec, P < 0.001) and at 60 min (176 ± 72 vs 73 ± 7 sec, P = 0.004).

CONCLUSIONS

The novel miniaturized roller pump circuit can be used to mimic extracorporeal circulation for selected research questions. Dextran-based priming caused a significant impairment in haemostasis compared with a standard crystalloid solution.

Effect of in-plane and out-of-plane bifurcated microfluidic channels on the flow of aggregating red blood cells

The blood flow through our microvascular system is a renowned difficult process to understand because the complex flow behavior of blood is intertwined with the complex geometry it has to flow through. Conventional 2D microfluidics has provided important insights, but progress is hampered by the limitation of 2-D confinement. Here we use selective laser-induced etching to excavate non-planar 3-D microfluidic channels in glass that consist of two generations of bifurcations, heading towards more physiological geometries. We identify a cross-talk between the first and second bifurcation only when both bifurcations are in the same plane, as observed in 2D microfluidics. Contrarily, the flow in the branch where the second bifurcation is perpendicular to the first is hardly affected by the initial distortion. This difference in flow behavior is only observed when red blood cells are aggregated, due to the presence of dextran, and disappears by increasing the distance between both generations of bifurcations. Thus, 3-D structures scramble in-plane flow distortions, exemplifying the importance of experimenting with truly 3D microfluidic designs in order to understand complex physiological flow behavior.

Intraoperative Infusion of Dextran Confers No Additional Benefit after Carotid Endarterectomy but Is Associated with Increased Perioperative Major Adverse Cardiac Events

BACKGROUND

Intraoperative dextran infusion has been associated with reduction of an embolic risk in patients undergoing carotid endarterectomy (CEA). Nonetheless, dextran has been associated with adverse reactions, including anaphylaxis, hemorrhage, cardiac, and renal complications. Herein, we aimed to compare the perioperative outcomes of CEA stratified by the use of intraoperative dextran infusion using a large multiinstitutional dataset.

METHODS

Patients undergoing CEA between 2008 and 2022 from the Vascular Quality Initiative database were reviewed. Patients were categorized by use of intraoperative dextran infusion, and demographics, procedural data, and in-hospital outcomes were compared. Logistic regression analysis was utilized to adjust for differences in patients while assessing the association between postoperative outcomes and intraoperative infusion of dextran.

RESULTS

Of 140,893 patients undergoing CEA, 9,935 (7.1%) patients had intraoperative dextran infusion. Patients with intraoperative dextran infusion were older with lower rates of symptomatic stenosis (24.7% vs. 29.3%; P < 0.001) and preoperative use of antiplatelets, anticoagulants and statins. Additionally, they were more likely to have severe carotid stenosis (>80%; 49% vs. 45%; P < 0.001) and undergo CEA under general anesthesia (96.4% vs. 92.3%; P < 0.001), with a more frequent use of shunt (64.4% vs. 49.5%; P < 0.001). After adjustment, multivariable analysis showed that intraoperative dextran infusion was associated with higher odds of in-hospital major adverse cardiac events (MACE), including myocardial infarction [MI] (odds ratio [OR], 1.76, 95% confidence interval [CI]: 1.34-2.3, P < 0.001), congestive heart failure [CHF] (OR, 2.15, 95% CI: 1.67-2.77, P = 0.001), and hemodynamic instability requiring vasoactive agents (OR, 1.08, 95% CI: 1.03-1.13, P = 0.001). However, it was not associated with decreased odds of stroke (OR, 0.92, 95% CI: 0.74-1.16, P = 0.489) or death (OR, 0.88, 95% CI: 0.58-1.35, P = 0.554). These trends persisted even when stratified by symptomatic status and degree of stenosis.

CONCLUSIONS

Intraoperative infusion of dextran was associated with increased odds of MACE, including MI, CHF, and persistent hemodynamic instability, without decreasing the risk of stroke perioperatively. Given these results, judicious use of dextran in patients undergoing CEA is recommended. Furthermore, careful perioperative cardiac management is warranted in select patients receiving intraoperative dextran during CEA.

Risk factors for intraoperative blood loss in resection of intracranial meningioma: Analysis of 530 cases

PURPOSE

Excision of intracranial meningioma has been associated with major intraoperative blood loss (IBL). The objective of the study was to identify factors affecting IBL during removal of meningioma.

METHODS

We retrospectively studied medical records of 530 adult patients who underwent surgery for intracranial meningioma at Sichuan Provincial People's Hospital between September 2018 and May 2022. We obtained the following data from each patient's medical chart: age, sex, height, weight, comorbidities, blood pressure, history of smoking and alcohol, imaging examination findings, pathologic diagnosis, albumin, creatinine, calcium, magnesium, hemoglobin (Hb), hematocrit, platelet count, activated partial thromboplastin time, international normalized ratio, fibrinogen concentration and blood transfusion. Univariate and multivariate analyses were performed to identify risk factors for greater IBL during removal of intracranial meningioma.

RESULTS

A total of 530 patients were included in our study. Univariate analysis revealed that sex (p = 0.004), two-dimensional (2D) tumor area (p < 0.001), sinus involvement (p = 0.014), World Health Organization grade (p = 0.015), preoperative albumin level (p = 0.032), preoperative Hb level (p = 0.001) and preoperative platelet count (p = 0.004) were significantly associated with greater IBL. Multivariate analysis revealed that greater 2D tumor area (p < 0.001), higher preoperative albumin concentration (p = 0.029) and higher preoperative platelet count (p = 0.03) were independent risk factors for greater IBL in resection of intracranial meningioma.

CONCLUSION

Larger tumor size, higher preoperative albumin concentration and higher preoperative platelet count were identified as independent risk factors for greater IBL in resection of intracranial meningioma.

Hemostatic effects of a dextran-based priming solution for cardiopulmonary bypass: A secondary analysis of a randomized clinical trial

INTRODUCTION

Intravascular fluids administered to patients may influence hemostasis. In patients undergoing cardiac surgery with cardiopulmonary bypass, the heart-lung machine is primed with 1300 ml of fluid. We assessed postoperative coagulation and platelet function in patients randomized to two different priming solutions, one colloid-based (dextran 40) and one crystalloid-based.

MATERIALS AND METHODS

Eighty-four elective cardiac surgery patients were randomized to either a dextran-based prime or Ringer's acetate with added mannitol. Blood samples were collected before, and 2 and 24 h after cardiopulmonary bypass. Coagulation was assessed by standard coagulation tests and rotational thromboelastometry. Platelet function was assessed with impedance aggregometry. Bleeding volumes and transfusion requirements were recorded.

RESULTS

Comparing the groups 2 h after bypass, the dextran group showed lower hemoglobin concentration, hematocrit, platelet count, and fibrinogen concentration, and higher INR and aPTT, as well as longer clot formation time (+41 ± 21 % vs. +8 ± 18 %, p < 0.001) and a larger reduction in fibrinogen-dependent clot strength (-37 ± 12 % vs. -7 ± 20 %, p < 0.001). Adenosine diphosphate-dependent platelet activation was reduced in the dextran group but not in the crystalloid group 2 h after bypass (-14 ± 29 % vs. -1 ± 41 %, p = 0.041). No significant between-group differences in hemostatic variables remained after 24 h, and no significant differences in perioperative bleeding volumes, re-explorations for bleeding, or transfusion rates were observed.

CONCLUSIONS

Compared to a crystalloid solution, a dextran-based prime had measurable negative impact on hemostatic variables but no detectable increase in bleeding volume or transfusion requirements in cardiac surgery patients.

Polymeric Materials for Hemostatic Wound Healing

Hemorrhage is one of the greatest threats to life on the battlefield, accounting for 50% of total deaths. Nearly 86% of combat deaths occur within the first 30 min after wounding. While external wound injuries can be treated mostly using visual inspection, abdominal or internal hemorrhages are more challenging to treat with regular hemostatic dressings because of deep wounds and points of injury that cannot be located properly. The need to treat trauma wounds from limbs, abdomen, liver, stomach, colon, spleen, arterial, venous, and/or parenchymal hemorrhage accompanied by severe bleeding requires an immediate solution that the first responders can apply to reduce rapid exsanguinations from external wounds, including in military operations. This necessitates the development of a unique, easy-to-use, FDA-approved hemostatic treatment that can deliver the agent in less than 30 s and stop bleeding within the first 1 to 2 min at the point of injury without application of manual pressure on the wounded area.

A comparison of the hemodynamic effects of fluid bolus therapy with crystalloids vs. 4% albumin and vs. 20% albumin in patients after cardiac surgery

BACKGROUND

Crystalloids, 4% albumin and 20% albumin are used for fluid bolus therapy (FBT) in patients after cardiac surgery. However, their detailed early (30 min) hemodynamic effects remain unstudied.

METHODS

In a comparative prospective observational trial of 120 ventilated, we studied post cardiac surgery patients who received crystalloid 500 ml FBT, 4% albumin 500 ml FBT or 20% albumin 100 ml FBT (40 per group). We recorded second-by-second hemodynamic parameters and 15-minutely cardiac index (CI) data before and for 30 min after FBT. We compared the crystalloid group (reference) vs. the 4% albumin group, and vs. the 20% albumin group.

RESULTS

Immediately after FBT, the mean (standard deviation) CI increase was 0.4 (0.4) L/min/m² with crystalloids, 0.4 (0.5) L/min/m² with 4% albumin and 0.3 (0.4) L/min/m² with 20% albumin, despite the much smaller FBT volume with 20% albumin. Mean arterial pressure (MAP) increase was 11 (10), 12 (9) and 9 (6) mm Hg, respectively. There was no group effect or interaction for changes in CI. However, there were time-group interactions for MAP changes such that crystalloid FBT had faster MAP reduction than 4% (p<0.001) or 20% albumin (p < 0.001). Moreover, patients treated with crystalloid FBT showed a faster decline in central venous pressure, perfusion pressure than the two groups. Finally, 20% albumin attenuated the fall in temperature induced by FBT.

CONCLUSION

In postoperative cardiac surgery patients, after a similar initial CI and MAP response, the MAP effect of crystalloid FBT dissipates faster than that of 4% or 20% albumin FBT. These findings can be used to inform clinical practice.

Colloids Yes or No? - a "Gretchen Question" Answered

Colloid solutions, both natural and synthetic, had been widely accepted as having superior volume expanding effects than crystalloids. Synthetic colloid solutions were previously considered at least as effective as natural colloids, as well as being cheaper and easily available. As a result, synthetic colloids (and HES in particular) were the preferred resuscitation fluid in many countries. In the past decade, several cascading events have called into question their efficacy and revealed their harmful effects. In 2013, the medicines authorities placed substantial restrictions on HES administration in people which has resulted in an overall decrease in their use. Whether natural colloids (such as albumin-containing solutions) should replace synthetic colloids remains inconclusive based on the current evidence. Albumin seems to be safer than synthetic colloids in people, but clear evidence of a positive effect on survival is still lacking. Furthermore, species-specific albumin is not widely available, while xenotransfusions with human serum albumin have known side effects. Veterinary data on the safety and efficacy of synthetic and natural colloids is limited to mostly retrospective evaluations or experimental studies with small numbers of patients (mainly dogs). Large, prospective, randomized, long-term outcome-oriented studies are lacking. This review focuses on advantages and disadvantages of synthetic and natural colloids in veterinary medicine. Adopting human guidelines is weighed against the particularities of our specific patient populations, including the risk-benefit ratio and lack of alternatives available in human medicine.

Temperature and haemodynamic effects of a 100 mL bolus of 20% albumin at room versus body temperature in cardiac surgery patients

Objective: To study the temperature and haemodynamic effects of room versus body temperature 20% albumin fluid bolus therapy (FBT). Design: Single-centre, prospective, before-after trial. Setting: A tertiary intensive care unit (ICU) in Australia. Participants: Sixty ventilated post-cardiac surgery patients. Intervention: Room versus body temperature 100 mL 20% albumin FBT. Main outcome measures: We recorded haemodynamic data from FBT start to 30 minutes after FBT. The cardiac index (CI) response was defined by a CI increase > 15%, and the mean arterial pressure (MAP) response was defined by a MAP increase > 10%. Outcomes: Immediately after FBT, median blood temperature decreased by -0.1°C (interquartile range [IQR], -0.1 to 0.0°C) with room temperature albumin versus 0.0°C (IQR, -0.1 to 0.0°C) with body temperature albumin (P < 0.001). The CI or MAP responses were similar. There was, however, a time and study group interaction for blood temperature (P < 0.001) for absolute and relative changes. In addition, mean pulmonary arterial pressure (PAP) (P = 0.002) increased more with body temperature albumin and remained higher for most of the observation period. Conclusion: Compared with room temperature albumin FBT, body temperature 20% albumin FBT prevents FBT-associated blood temperature fall and increases mean PAP. However, CI and MAP changes were the similar between the two groups, implying that fluid temperature has limited haemodynamic effects in these patients.

Comparison of Two Different Fibrinogen Concentrates in an in vitro Model of Dilutional Coagulopathy

Introduction

Fibrinogen concentrates are widely used to restore clot stability in situations of bleeding. Fibrinogen preparations are produced using different production methods, resulting in different compounds. Thus, different preparations might have a distinct impact on blood coagulation. We tested the effect of fibrinogen concentrates Haemocomplettan® (CSL Behring, Marburg, Germany) and fibryga® (Octapharma GmbH, Langenfeld, Germany) on the impairments induced by 60% dilutional coagulopathy in vitro.

Materials and Methods

The influence of the fibrinogen concentrates fibryga® and Haemocomplettan® on colloid (gelatine, hydroxyethyl starch [HES], albumin)-induced or crystalloid (Ringer's acetate)-induced dilutional coagulopathy was analysed using rotational thromboelastometry (ROTEM®) and standard laboratory tests. The following experimental conditions were analysed in vitro: whole blood, 60% dilution (40% blood and 60% diluent) ± 50 or 100 mg/kg^-1 fibryga® or Haemocomplettan®, respectively.

Results

Dilution with either diluent resulted in prolonged clotting time (CT) in an extrinsic activated test (CT_EXTEM) and decreased maximum clot firmness (MCF_FIBTEM) as expressed, e.g., by gelatine: (59.5 s [62/54.8] vs. 95 s [102.8/86.8]; p < 0.001 and 14 mm [16/10.5] vs. 3 mm [4-3]; p < 0.001). Substitution after 60% dilution with HES resulted in no difference between the preparations, except for shorter thrombin time with fibryga® (14 s [15/14] vs. 18 s [18.8/17]; p = 0.0093; low dose). CT_EXTEM was higher with Haemocomplettan® in a gelatine-induced dilution (51 s [54.5/47.5] vs. 63 s [71/60.3]; p = 0.0202; low dose) whereas thrombin time was lower with fibryga® (19.5 s [20.8/19] vs. 27 s [29/25.3]; p = 0.0017). In dilution with albumin, differences in CT_EXTEM (69 s [76.5/66] vs. 56 s [57/53.3]; p = 0.0114; low dose) and thrombin time (18 s [18/17] vs. 24.5 s [25.8/24]; p = 0.0202; low dose) were seen. In dilution with crystalloid solution, again differences in CT_EXTEM (53.5 s [57.8/53] vs. 45 s [47/43]; p = 0.035; low dose) and thrombin time (17 s [17/16] vs. 23.5 s [24/23]; p = 0.0014; low dose) were seen. Fibrinogen levels were more increased by high-dose substitution of both preparations.

Conclusion

Based on this data it can be stated that both fibryga® and Haemocomplettan® had the same performance in our in vitro model except for CT_EXTEM and thrombin time.

Albumin combined with Mannitol impairs whole blood coagulation and platelet function in vitro

BACKGROUND

The indication of hydroxyethyl starch is currently under critical discussion and albumin 5% (ALB) has an increasing use in the operating theatre. Therefore, ALB is routinely used in neurosurgical procedures and often combined with mannitol 20% (MAN). Purpose of this in vitro study was to determine the influence of the combination of MAN and ALB on blood coagulation and platelet function.

METHODS

22 healthy volunteers were included into this study and 21 analysed. Blood was obtained and diluted into five groups: (1) 7% dilution with MAN, (2) 10% dilution with ALB (3) 17% dilution with isotonic balanced electrolyte solution, (4) 17% dilution with MAN + ALB and (5) undiluted blood as control group (CON). Rotational thrombelastometry via ROTEM® (EXTEM, FIBTEM-Test) and thrombocyte aggregometry via Multiplate® (ASPI, ADP and TRAP-test) were used to detect differences within the intervention groups and compared to the control group.

RESULTS

The maximum clot firmness in the FIBTEM test decreased under the normal range with the combination of MAN+ALB: 8mm (5.5-11) compared to CON: 15mm (12.5-20), p<0.05. Platelet function (ADP-test) showed significant decreases for ALB: 51 AUC (40-84) and MAN+ALB: 54 AUC (41-68) compared to CON: 92 AUC (75-101), p<0.05. Except in clotting time all other EXTEM tests of MAN+ALB subgroup showed significant impairment on blood coagulation compared to the control group.

CONCLUSIONS

In this in vitro study clinically relevant dilutions of MAN+ALB showed a significant inhibition of blood coagulation and platelet function. Further in vivo studies are necessary to confirm these results.