Effects of different colloid infusions on ROTEM and Multiplate during elective brain tumour neurosurgery

Effect of mannitol on platelet function during elective craniotomy in adult patients with brain tumor

BACKGROUND

Mannitol is used in the treatment of raised intracranial pressure (ICP). The aim of this study was to investigate whether mannitol (MAN) leads to a relevant deterioration in platelet function in routine neurosurgical procedures.

METHODS

Thirty-eight patients undergoing elective craniotomy due to a brain tumor with elevated ICP were included. After induction of anesthesia a blood sample was taken (T1). The patients then received 1 g∙kg-1 MAN within 30 minutes. The second blood sample (T2) was obtained 60 minutes after T1. Blood samples were examined by means of aggregometry (Multiplate®; Roche, Basel, Switzertland) and PFA-100® tests (Siemens Healthineers, Erlangen, Germany).

RESULTS

No patient had clinical signs of increased bleeding. We could not find any deterioration in the aggregometry using Multiplate® (Roche), neither in the adenosine diphosphate (ADP), the arachidonic acid (ASPI), or the thrombin receptor activating protein (TRAP) test. PFA-100® (Siemens Healthineers) closing times (cT) showed a significant prolongation between T1 and T2: collagen/adenosine diphosphate (COL/ADP) test 79 s [70/99] and 91 s [81/109]; P=0.002); collagen/epinephrine (COL/EPI) test 109 s [92/129] and 122 s [94/159]; P=0.0004). A subgroup analysis showed that the patients who received isotonic balanced infusions only, had no prolongation of cT, whereas the patients who received additionally gelatin solution had a significant prolongation. COL/ADP: 78 s [70/98] and 91 s [82/133]; P=0.0004). COL/EPI: test 111 s [92/128] and 127 s [103/146]; P=0.0026). Except for individual outliers, the measured values were in the normal range.

CONCLUSIONS

In this study, we found no clinically relevant deterioration of platelet function in neurosurgical patients with increased ICP after administration of MAN. Changes that occurred were all within normal ranges.

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.

In Vivo Effects of Balanced Crystalloid or Gelatine Infusions on Functional Parameters of Coagulation and Fibrinolysis: A Prospective Randomized Crossover Study

Prudent administration of fluids helps restore or maintain hemodynamic stability in the setting of perioperative blood loss. However, fluids may arguably exacerbate the existing coagulopathy. We sought to investigate the influence of balanced crystalloid and synthetic gelatine infusions on coagulation and fibrinolysis in healthy volunteers. This prospective randomized crossover study included 25 males aged 18–30 years. Infusions performed included 20 mL/kg of a balanced crystalloid solution (Optilyte^®) or 20 mL/kg of gelatine 26.500 Da (Geloplasma^®) in a random order over a period of 2 weeks. Laboratory analysis included conventional coagulation parameters and rotational thromboelastometry (ROTEM) assays. We confirmed a decrease in fibrinogen concentration and the number of platelets, and prolongation of PT after infusions. Compared to baseline values, differences in the ROTEM assays’ results after infusions signified the decrease in coagulation factors and fibrinogen concentration, causing impaired fibrin polymerization and clot structure. The ROTEM indicator of clot lysis remained unaffected. In the case of both Optilyte^® and Geloplasma^®, the results suggested relevant dilution. Gelatine disrupted the process of clot formation more than balanced crystalloid. Infusions of both crystalloid and saline-free colloid solutions causing up to 30% blood dilution cause significant dilution of the coagulation factors, platelets, and fibrinogen. However, balanced crystalloid infusion provides less infusion-induced coagulopathy compared to gelatine.

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.

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.

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

Background

Hydroxyethyl starches have been withdrawn from the European market. In Sweden, dextran was the main colloid until 2000, when starches overtook the market. After the recent 6S-trial, it was suggested that dextran could be reinstituted, but concerns for greater coagulopathy, bleeding and anaphylaxis still remain. An experimental study from our department indicated that isovolemic substitution of dextran-70 did not derange the von Willebrand function more than albumin 5%, considering the fact that dextran is hyperoncotic in comparison to albumin 5% and, therefore, induces a greater plasma volume expansion and thereby a greater dilutional coagulopathy.

Methods

Eighteen patients undergoing major gynaecological surgery were assigned to receive either 5% albumin or 6% dextran-70 with 9 patients in each group. Standard coagulation tests, including prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen and platelet count, viscoelastic coagulation test thromboelastometry (ROTEM) and the Multiplate platelet aggregation test were used to test for coagulation defects at different time points perioperatively. Blood loss, blood loss replacement data and haemodynamic parameters were retrieved from anaesthetic and postoperative charts. A local departmental fluid and transfusion/infusion protocol assured haemoglobin > 90 g/l and mean arterial pressure > 65 mmHg with Ringer’s acetate in addition to the colloid use.

Results

There were no differences in demographic data between the groups. The tissue factor-activated (EXTEM) clot-structure parameter ROTEM A10 was decreased significantly in the dextran group as compared to the albumin group after the infusion of 500 ml of either colloid solution. The PT and aPTT were significantly prolonged, and the platelet count decreased postoperatively in the dextran group, whereas albumin only deranged fibrinogen levels as compared to preoperative levels. There were no differences in Multiplate platelet aggregometry, amount of haemorrhage or transfusion of blood components between the groups.

Conclusions

Standard plasma-based coagulation tests, platelet count and whole blood viscoelastic clot structure are affected by 6% dextran-70 to a greater extent than by 5% albumin, but platelet aggregation is not. Future studies should use more advanced haemodynamic monitoring to assess isovolemic plasma volume expansion with dextran and whether this affects haemostasis to a lesser degree.

Anaemia and red blood cell transfusion in intracranial neurosurgery: a comprehensive review

Both anaemia and blood transfusion are associated with poor outcomes in the neurosurgical population. Based on the available literature, the optimal haemoglobin concentration for neurologically injured patients appears to be in the range of 9.0-10.0 g dl^-1, although the individual risks and benefits should be weighed. Several perioperative blood conservation strategies have been used successfully in neurosurgery, including correction of anaemia and coagulopathy, use of antifibrinolytics, and intraoperative cell salvage. Avoidance of non-steroidal anti-inflammatory drugs and starch-containing solutions is recommended given the potential for platelet dysfunction.

Comparison of citrated and fresh whole blood for viscoelastic coagulation testing during elective neurosurgery

BACKGROUND

Previous viscoelastic haemostatic tests studies have often indicated a hypercoagulative test signal with citrated blood, which could influence clinical decision makings.

PURPOSE

The aim of this study was to compare fresh and citrated whole blood using two non-automated viscoelastic ROTEM and Sonoclot tests. Our hypothesis was that citrated blood would demonstrate a hypercoagulative response in this setting, not tested before.

METHODS

Perioperative viscoelastic coagulation changes were evaluated with a ROTEM and Sonoclot in 38 patients undergoing elective brain tumor surgery. The citrated samples were recalcified with CaCl₂. Wilcoxon nonparametric-paired tests and Bland-Altman plots were performed to compare the fresh and citrated blood analyses.

RESULTS

The citrated blood showed a hypercoagulative response in ROTEM NATEM-clot formation time and α-angle, Sonoclot-clot rate and platelet function, as compared to fresh blood (p<0.0001).

CONCLUSIONS

Fresh whole blood may theoretically reflect in vivo haemostasis more closely than citrated analyses, which indicated a hypercoagulative response as compared to the fresh whole blood analyses Bland-Altman plots also indicated that ROTEM reference ranges in patients undergoing brain surgery should be redefined. Future studies must establish the correlation between viscoelastic test results using fresh or citrate anticoagulated blood and clinical outcomes, such as bleeding, transfusion or reoperation for postoperative haematoma.