Coagulation during elective neurosurgery with hydroxyethyl starch fluid therapy: an observational study with thromboelastometry, fibrinogen and factor XIII

Use of viscoelastic monitoring and prothrombin complex concentrate in a paediatric patient with polytrauma and severe traumatic brain injury

Viscoelastic monitoring (VEM) tools, such as rotational thrombelastometry, have been used extensively to measure coagulopathy in adults but have received less attention in paediatric care. The presented case involves a 5-year-old boy who was brought to the emergency department after a motor vehicle collision with a Glasgow Coma Scale score of 6T and extensive injuries, including a subdural hematoma. VEM was used to monitor the patient's coagulopathy and to inform treatment measures by allowing real-time visualisation of the patient's coagulation status. VEM was additionally used to direct blood product replacement in preparation for neurosurgical intervention, and 4-factor prothrombin complex concentrate (PCC) was used to help reverse the coagulopathy. The patient underwent successful hemicraniectomy after improvement of his coagulopathy. In paediatrics, VEM and PCC are increasingly being used for post-trauma coagulopathy, and this case highlights their potential promise and the need for further research.

Safety and efficacy of peri-operative administration of hydroxyethyl starch in children undergoing surgery: A systematic review and meta-analysis

BACKGROUND

Hydroxyethyl starch (HES) solutions have shown their efficiency for intravascular volume expansion. A safety recommendation limiting their use in adult patients has recently been made.

OBJECTIVE

To assess the efficacy and adverse effects of HES when administered intra-operatively to paediatric patients.

DESIGN

Systematic review with meta-analyses. Data were analysed using classical mean differences [and their 95% confidence intervals (CIs)] and trial sequential analysis. A Grading of Recommendations Assessment, Development and Evaluation (GRADE) classification was performed for all outcomes. Reviewers extracted valid data, including perioperative total fluid intakes, mortality, renal function, coagulation tests, blood loss and length of hospital and ICU stay.

DATA SOURCES

Searches were performed in databases (Pubmed, Embase, Cochrane central register of controlled trials), clinical trials register, and open access journals not indexed in major databases.

ELIGIBILITY CRITERIA

Randomised controlled trials (RCTs) published before December 2016 involving paediatric patients who received 6% low molecular weight HES.

RESULTS

Nine RCTs involving 530 peri-operative paediatric patients were analysed. Compared with other fluids, HES did not significantly modify the amount of peri-operative fluid administered [mean difference 0.04; 95% CI (-1.76 to 1.84) ml kg], urine output [mean difference -33; 95% CI (-104 to 38) ml kg] or blood loss [mean difference -0.09; (-0.32 to 0.15) ml kg]. Trial sequential analysis determined that the outcomes for peri-operative fluid and urine output were underpowered. All results were graded as very low quality of evidence.

CONCLUSION

Intravascular volume expansion with low molecular weight 6% HES did not appear to modify renal function, blood loss or transfusion when administered to children during the peri-operative period. However, given the lack of statistical power and the very low GRADE quality of evidence, more high-quality RCTs are needed to explore these outcomes.

The Relationship Between Colloid Transfusion During Surgical Decompression Hemicraniectomy Period and Postoperative Pneumonia or Long-Term Outcome After Space-Occupying Cerebral Infarction: A Retrospective Study

BACKGROUND

Colloid transfusion during surgical decompressive hemicraniectomy (DHC) to treat space-occupying cerebral infarction induced by middle cerebral artery (MCA) is controversial. A multicenter retrospective study was conducted to determine whether an increased colloid transfusion during surgery is associated with a lower incidence of postoperative pneumonia and better long-term outcomes after space-occupying cerebral infarction.

METHODS

Data from surgical DHC within 48 hours to treat space-occupying cerebral infarction that took place between November 30, 2013, and March 30, 2016, were collected in a multicenter chart. Univariate analysis, Spearman correlation, χ² test, and bivariate and multivariate logistic regression were performed to account for the associations between colloid transfusion and postoperative pneumonia or long-term outcomes (indicated by modified Rankin Scale [mRS] scores).

RESULTS

Univariate analysis showed that surgical duration and mRS were significantly different between the subjects older and younger than 60 years who underwent surgical DHC (P < 0.05). In the entire population studied, increased National Institutes of Health Stroke Scale was associated with a greater incidence of postoperative pneumonia (odds ratio [OR] 1.255, P = 0.003) and increased mRS (OR 1.229, P = 0.014). In the population older than 60 years, it was revealed that increased colloid transfusion was associated with a lower incidence of postoperative pneumonia (OR 0.761, P = 0.030) or better outcomes, as indicated with lower mRS (OR 0.837, P = 0.045).

CONCLUSIONS

Our retrospective study demonstrated that there is a robust association between increased perioperative colloid transfusion and lower incidence of postoperative pneumonia and better outcomes among the patients older than 60 years after space-occupying cerebral infarction.

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.

Warfarin monitoring with viscoelastic haemostatic assays, thrombin generation, coagulation factors and correlations to Owren and Quick prothrombin time

The anticoagulant warfarin is commonly monitored with prothrombin time (PT). Viscoelastic haemostatic assays (VHA) are primarily used in situations of acute bleeding to guide haemostatic therapy. Much research has focused on VHA monitoring of new oral anticoagulants. However, many patients are still anticoagulated with warfarin and effect of warfarin anticoagulation on VHA is uncertain. The aim of this study was to assess warfarin anticoagulation on three different VHA and compare these findings with prothrombin time (PT), coagulation factor analyses and a thrombin generation assay (TGA). Citrated whole blood was drawn from 80 patients admitted for routine PT-INR Owren. VHA analysis with ROTEM (EXTEM, INTEM and FIBTEM), ReoRox (Fibscreen 1 and 2) and Sonoclot (gbACT+) was performed. Blood was also drawn for plasma analysis with PT (PT-INR Owren and PT Quick), TGA and analysis of factors I, II, VII, IX and X. Extrinsically activated VHA, including ROTEM EXTEM and FIBTEM Clotting Time (CT) and ReoRox Fibscreen1 and 2 clot onset time 1 correlated moderately with PT-INR Owren , with R 0.66-0.71. These four variables were likely to be prolonged above reference interval in patients with prolonged PT-INR Owren >1.2. Two patients with normal ROTEM CTs had Owren PT-INRs >1.5. Warfarin affects extrinsically activated VHA variables of initial clotting. The role of VHA for clinical decision-making in patients planned for invasive procedures, such as spinal/epidural anaesthesia needs further study. None of the recent guidelines on regional anaesthesia include VHA testing to define adequate haemostasis.