[Rotational thromboelastometry assessment of ballanced crystalloid, hydroxyethyl starch and gelatin effects on coagulation: a randomized trial]. / Tromboelastometria rotacional na avaliação dos efeitos de cristaloides balanceados, hidroxietilamido e gelatina na coagulação: estudo randômico.

BACKGROUND AND OBJECTIVES: Modern crystalloid and colloid solutions are balanced solutions which are increasingly used in perioperative period. However, studies investigating their negative effect on whole blood coagulation are missing, and vivid debate is going on about which solution has the minimal coagulopathy effect. The aim of our study was to assess the effect of modern fluid solutions on whole blood coagulation using rotational thromboelastometry. METHODS: Blood samples were obtained from 30 patients during knee arthroscopy before and after administration of 500mL of crystalloid, Hydroxyethyl Starch and gelatin according to the randomization. Rotational thromboelastometry (Extem, Intem and Fibtem tests) was used to assess negative effect of fluid solutions on whole blood coagulation. RESULTS: In Extem test, the initiation phase of fibrin clot formation represented by CT parameter was not influenced by any fluid solution (p>0.05). The speed of clot formation represented by CFT and α angle was impaired by Hydroxyethyl Starch and gelatin but not by crystalloids (p<0.05). The strength of formatted coagulum represented by MCF parameter was impaired both in Extem and Fibtem test by HES and in Fibtem also by crystalloids (p<0.05). Intem test was not negatively influenced by any crystalloid or colloid solution in any parameter (p>0.05). CONCLUSION: Extem test appears to be sensitive to coagulopathy effect of modern colloids and crystalloids. Hydroxyethyl starch has the most obvious negative effect on clot formation followed by gelatin and finally by crystalloids. Intem test seems to be insensitive to adverse effect of modern colloids and crystalloids.

Rotational thromboelastometry assessment of ballanced crystalloid, hydroxyethyl starch and gelatin effects on coagulation: a randomized trial / Tromboelastometria rotacional na avaliação dos efeitos de cristaloides balanceados, hidroxietilamido e gelatina na coagulação: estudo randômico

Abstract Background and objectives Modern crystalloid and colloid solutions are balanced solutions which are increasingly used in perioperative period. However, studies investigating their negative effect on whole blood coagulation are missing, and vivid debate is going on about which solution has the minimal coagulopathy effect. The aim of our study was to assess the effect of modern fluid solutions on whole blood coagulation using rotational thromboelastometry. Methods Blood samples were obtained from 30 patients during knee arthroscopy before and after administration of 500 mL of crystalloid, Hydroxyethyl Starch and gelatin according to the randomization. Rotational thromboelastometry (Extem, Intem and Fibtem tests) was used to assess negative effect of fluid solutions on whole blood coagulation. Results In Extem test, the initiation phase of fibrin clot formation represented by CT parameter was not influenced by any fluid solution (p > 0.05). The speed of clot formation represented by CFT and α angle was impaired by Hydroxyethyl Starch and gelatin but not by crystalloids (p < 0.05). The strength of formatted coagulum represented by MCF parameter was impaired both in Extem and Fibtem test by HES and in Fibtem also by crystalloids (p < 0.05). Intem test was not negatively influenced by any crystalloid or colloid solution in any parameter (p > 0.05). Conclusion Extem test appears to be sensitive to coagulopathy effect of modern colloids and crystalloids. Hydroxyethyl starch has the most obvious negative effect on clot formation followed by gelatin and finally by crystalloids. Intem test seems to be insensitive to adverse effect of modern colloids and crystalloids.

Resumo Justificativa e objetivos Os cristaloides e coloides modernos são soluções balanceadas e cada vez mais utilizadas no período perioperatório. No entanto, não há estudos que avaliem seu efeito negativo na coagulação do sangue total e o intenso debate sobre a solução que cause um efeito mínimo na coagulopatia permanece. O objetivo de nosso estudo foi avaliar o efeito das soluções líquidas modernas na coagulação do sangue total com o uso da tromboelastometria rotacional. Métodos De acordo com a randomização, amostras de sangue foram colhidas de 30 pacientes durante a artroscopia de joelho, antes e após a administração de 500 mL de cristaloides, hidroxietilamido e gelatina. A tromboelastometria rotacional (testes Extem, Intem e Fibtem) foi utilizada para avaliar o efeito negativo das soluções líquidas na coagulação do sangue total. Resultados No teste Extem, a fase de iniciação da formação de coágulos de fibrina representada pelo parâmetro CT não foi influenciada por qualquer solução líquida (p > 0,05). A velocidade da formação de coágulos representada pelo CFT e pelo ângulo α foi prejudicada pelo hidroxietilamido e pela gelatina, mas não pelos cristaloides (p < 0,05). A força do coágulo formatado representado pelo parâmetro MCF foi prejudicada tanto no teste Extem quanto no teste Fibtem pelo HES e no teste Fibtem também pelos cristaloides (p < 0,05). O teste Intem não foi influenciado negativamente por nenhuma solução cristaloide ou coloide em nenhum parâmetro (p > 0,05). Conclusão O teste Extem parece ser sensível ao efeito de coagulopatia dos coloides e cristaloides modernos. O hidroxietilamido apresentou o efeito negativo mais óbvio na formação do coágulo, seguido pela gelatina e finalmente pelos cristaloides. O teste Intem parece ser insensível ao efeito adverso dos coloides e cristaloides modernos.

Effect of Balanced Crystalloid, Gelatin and Hydroxyethyl Starch on Coagulation Detected by Rotational Thromboelastometry In Vitro.

BACKGROUND: Fluid resuscitation with crystalloid and colloid solutions is a common treatment in perioperative medicine. However, a variety of unbalanced or balanced solutions are used in clinical practice and there is still vivid debate going on regarding selection of optimal fluid with minimal negative effect on coagulation to minimize bleeding and blood transfusion requirements. The aim of the study was to investigate adverse effects of balanced crystalloids and colloids on coagulation measured by thromboelastometry in vitro. METHODS: Blood samples were obtained from healthy volunteers undergoing knee arthroscopy. Adverse effects of balanced crystalloid, hydroxyethyl starch, and gelatin were evaluated by thromboelastometry after 20% dilution of blood with the solution in vitro. Parameters of EXTEM and FIBTEM test were evaluated. RESULTS: Clotting time of EXTEM was not significantly influenced by any of the investigated solutions (p > 0.05). However, significant impairment of clot formation time of EXTEM was detected in hydroxyethyl starch and gelatin groups in comparison with controls (p < 0.05), while crystalloid did not affect this parameter significantly (p > 0.05). Similar results were found in α angle although significant coagulopathy effect was found only in hydroxyethyl starch samples (p < 0.05). Maximum clot firmness of EXTEM and FIBTEM tests was significantly affected by both hydroxyethyl starch and gelatin (p < 0.05) but not by crystalloid. CONCLUSIONS: Balanced crystalloid solution does not seem to have a negative influence on the coagulation process as measured by thromboelastometry. On the other hand, balanced colloids may impair propagation phase of coagulation, strength of coagulum, and level of functional fibrinogen. Hydroxyethyl starch seems to have a stronger anticoagulant effect compared to gelatin.

Stability of Non-Activated Rotational Thromboelastometry Assay in Time of Citrated Blood (Appropriate Time Interval for Analysis).

BACKGROUND: Activated methods of thromboelastometry such as EXTEM and INTEM are routinely used in management of severe bleeding. However, sometimes the patient is bleeding despite the normal values of EXTEM/ INTEM. Non-activated thromboelastometry (NATEM) is the most sensitive to coagulopathy and shows pathologic results in such cases. However, it is necessary to find an appropriate time interval between blood sampling and NATEM analysis as the results are strongly influenced by time. METHODS: In 18 healthy volunteers we performed NATEM analyses of citrated blood samples at 0, 5, 10, 15, 20, 30, and 60 minutes after sampling. RESULTS: All NATEM parameters showed a procoagulation trend with the time elapsing from blood sample collection with coagulation time (CT) being the most sensitive parameter. After 20 minutes this parameter became relatively stable as the difference among CT at 20th, 30th, and 60th minute was not statistically significant (p > 0.05). The least differences of CT values with maximum time window were found between 30 and 60 minutes. CONCLUSIONS: Citrated blood sample becomes stable after 20 minutes of storage but the time window between 30 and 60 minutes seems to be more suitable for NATEM analysis in clinical practice.

Continuous non-invasive monitoring improves blood pressure stability in upright position: randomized controlled trial.

Intermittent blood pressure (BP) monitoring is the standard-of-care during low and intermediate risk anaesthesia, yet it could lead to delayed recognition of BP fluctuations. Perioperative hypotension is known to be associated with postoperative complications. Continuous, non-invasive methods for BP monitoring have been developed recently. We have tested a novel non-invasive, continuous monitor (using the volume clamp method) to assist with maintaining BP in safe ranges for patients undergoing surgery in a beach chair position. Forty adult patients undergoing thyroid gland surgery in an upright position were included in this prospective randomised controlled trial. Patients were equally allocated to the group with continuous monitoring of BP using the CNAP® Monitor and to the control group managed using an intermittent oscillometric BP cuff. The absolute and proportional time spent outside the range of ±20% of the target BP along with other hemodynamic and clinical parameters were evaluated. The continuous monitoring decreased the anaesthesia time spent below -20% pressure range [absolute: 12 min (4-20) vs. 27 min (16-34); p=0.001; relative to procedure length: 14% (7-20) vs. 33.5% (17.5-53); p=0.003]. No significant differences were observed in postoperative morbidity or in hospital length of stay. Continuous non-invasive BP monitoring via the CNAP® Monitor allows for better BP management in patients undergoing surgery in a beach chair position. In our randomised trial the time spent in hypotension was significantly shorter using continuous monitoring.