Nurse Corner |
Mr Chan Siu Kau |
|
APN, A&E, Pok Oi Hospital |
|
|
The co-implementation of eAED & Corporate Queue Management System (CQMS) pave the road to paperless
In the era of information technology, we have to keep up with the newest technology in healthcare services for the day-to-day challenges. eAED is one example. eAED is an electronic system for clinical documentation in AED. CQMS is a queue system provided by HAIT with round-the- clock support. These two systems have been successfully rolled out in POH AED in Oct 2019. Meanwhile, AE card is still issued as a communication tool. However, with the continuous enhancements of the systems, paperless AED is our ultimate goal.
In POH A&E, the quality and safety of patient care is enhanced by electronic consultation and documentation. Firstly, it enables healthcare workers of AED and various departments to access the most updated information of patients, which enhances the efficiency of AE procedures, facilitates the immediate deployment of manpower, and shortens patient’s waiting time. Besides, it enhances the data accuracy and reduces the potential misunderstanding caused by handwriting. Lastly, the data interface between the two systems reduces redundant entries and enhance efficiency.
When the patient approaches Triage, triage nurses use the eAED system to call and triage cases. After saving the notes, the queue ticket will be printed out automatically for non-urgent cases. For no-show patients on CQMS, the call time will be displayed on eAED. The systems simplify procedures, eg. allowing triage and queueing in the same window. Announcements are made in English, Cantonese and Putonghua.
Ticket enquiry allows patient particulars, triage categories and status to be retrieved on CQMS. The patient’s status is available on CQMS even without an AE card or access to eAED.
Real-time capture for triage, consultation and admission is accomplished after notes are saved in eAED. This enhances the accuracy of patients’ waiting and admission time.
eAED’s feature of immediate notification allows doctors to be notified immediately when investigation results are available on eList. It reduces the waiting time of patients and facilitates the patient flow.
Limitations of these systems include occupational safety and health issue concerns caused by long-term use of computers. Also, during downtime of CMS, staff still has to rely on traditional AE cards.
A small step makes a big change. To achieve a paperless environment, the key step is to build up a good communication system among different ranks of users in AED, with the use of electronic ECG, checklists, MOE and admissions.
|
|
Advance in EM |
Dr Lai Chun Yu |
|
Vice-chairman, Trauma Subcommittee, HKCEM
Associate Consultant, A&E, Prince of Wales Hospital |
|
|
Viscoelastic haemostatic assays (VHA) – thromboelastography (TEG) and rotational thromboelastometry (ROTEM®)
Overview
The potential clinical application of viscoelastic assay in the management of major bleeding has been attracting unprecedented interest in the last few years. Being a rapid point-of-care test for
|
|
|
haemostasis, viscoelastic haemostatic assay (VHA) is increasingly used in emergency departments, intensive care units and operating theatres. Thromboelastography (TEG) and rotational thromboelastometry (ROTEM®) are the two main commercially available methods of VHA in the market. Unlike other routine coagulation assays, VHA assesses the viscoelastic properties of clot formation in real time, and provides information about clot initiation, clot strength and subsequent fibrinolysis.
Testing method
The mechanism of VHA is to assess the haemostatic process in a condition that mimics the sluggish blood flow in veins. The theories behind TEG and ROTEM® are similar, but these two machines operate in slightly different ways. TEG measures the physical properties of a clot in whole blood via a pin suspended in an oscillating cup. By contrast, in ROTEM®, the sample is placed into a cuvette in which a cylindrical pin is immersed. As the pin rotates at a particular angle, the blood sample clots, and the clot thickness is detected optically by an integrated computer that converts the measured data into numerical parameters.1 In the following paragraphs, we shall focus on a description of ROTEM®. Figure 1 is the schematic diagram illustrating the operating method of ROTEM®.
|
|
|
Figure 1. ROTEM® Thromboelastometry detection method.1
|
|
By measuring the speed and strength of clot formation, a graph of clot amplitude against time is derived. The following are the key parameters measured by ROTEM®:
- Parameters related to the speed of clotting:
Clotting time (CT), Clot formation time (CFT), Alpha-angle
- Parameters related to the clot firmness:
Maximum clot firmness (MCF), Amplitude at 5, 10 and 20 minutes (A5, A10 and A20)
- Parameters related to the process of fibrinolysis:
Maximum lysis (ML), Lysis Index after 30 minutes (LI30)
Figure 2 is a graph of clot amplitude against time generated by a ROTEM® machine, and demonstrates how the key parameters are defined. Although TEG has different terminology, the principle is virtually the same.
|
|
|
Figure 2. ROTEM® thromboelastometry parameters and scaling.1
|
|
To facilitate rapid differentiation among numerous clotting defects and the effects of anticoagulants, different reagents are added to assess the function of various coagulation pathways. Assays such as INTEM, HEPTEM, EXTEM, FIBTEM and APTEM are generated to address specific conditions.
By pattern recognition of ROTEM tracing or application of VHA-guided algorithm, clotting factor concentrates and haemostatic drugs are given according to the patient’s need (Figure 3). In general, fresh frozen plasma or prothrombin complex concentrate (PCC) is indicated to treat prolonged clotting time, while cryoprecipitate is specific for a decrease in alpha angle. If the amplitude and MCF are diminished, platelets should be the most suitable therapeutic option. Fibrinogen concentrate administration should be considered when there is evidence of functional fibrinogen deficit as shown by lowered FIBTEM amplitude. Apart from administering empirical tranexamic acid based on CRASH-2 trial, a repeated dose of tranexamic acid is indicated when the signs of hyperfibrinolysis exist.
|
|
|
Figure 3. Example of treatment algorithm based on ROTEM®2
|
|
Advantages of VHA and its clinical applications
Thanks to the rapid turnover time of VHA, there is growing interest in its practical use as a point-of-care test in trauma resuscitation. VHA enables early diagnosis of acute coagulopathy of trauma and shock, which was regarded as a major challenge in the past with the conventional coagulation test (CCT). A pilot study of protocolised VHA-guided haemostatic management conducted by Gratz et al. showed that, thromboelastometric results were available 38 minutes earlier than that of the CCT. This might lead to more rapid and precise coagulation management.3
Not only does VHA measure the speed of coagulation, but also it depicts a holistic picture of coagulation dynamics and the sustainability of clot formation. Thus, a targeted and individualized therapeutic approach in bleeding management is made feasible. By increasing the accuracy of diagnosis of trauma-induced coagulopathy, VHA parameters are better predictors of adverse outcome and mortality compared with the CCT. A systematic review of ROTEM® revealed that the parameters measured by EXTEM and FIBTEM (A5, A10, A20, MCF) were consistently capable of diagnosing coagulopathy and predicted an increased risk of bleeding, massive transfusion and mortality. By means of interpretation of LI30 and ML level, the value of ROTEM® was also pronounced in the early detection of hyperfibrinolysis, that was strongly associated with mortality.4
Assisting decision making about the administration of blood components, VHA-guided thrombostatic resuscitation protocols, such as the TACTIC algorithms, have been developed and may emerge as the standard in the near future.5 These protocols are user-friendly and simplify the steps of decision making. With improved design of the new automatic VHA machines, they can be operated by medical personnel efficiently without the need of intensive training.
In the trauma setting, there was growing evidence demonstrating that VHA-guided haemostatic therapy was associated with a reduction of mortality, bleeding rate, transfusion requirements, complication rates and health care costs.2,6 According to the practice management guideline from the Eastern Association for Surgery and Trauma, a goal-directed component transfusion approach guided by TEG/ROTEM® was associated with fewer trauma patients requiring transfusion of packed cells (RR, 0.74; 95% CI, 0.67-0.82) and platelets (RR, 0.35; 95% CI, 0.22-0.55), fewer units of packed cells transfused (SMD, -0.38; 95% CI, -0.64 to -0.12) and a reduction in trauma mortality (RR, 0.75; 95% CI 0.59-0.95). It also led to a decrease in the number of blood transfusion-related complications.7
Besides, the application of VHA in other medical specialties similarly showed assuring results in clinical trials. First of all, the use of VHA in neurosurgery was shown to lead to consistent coagulation management, improved clot quality and decreased incidence of progressive haemorrhagic injury and neurosurgical re-intervention.8 Likewise, another recently published multi-centre randomised controlled trial on neurosurgical patients revealed the benefit of VHA use in a pre-specified subgroup with traumatic brain injury, 64% in the VHA arm were alive and free of massive transfusion compared to 46% in the CCT arm.9 Additionally, in the surgical patients and critically ill patients with ongoing haemorrhage and concern for coagulopathy, a reduction in blood component consumption and survival benefits were observed.7 To manage major bleeding in cardiac surgery, TEG/ROTEM® use was associated with decreased plasma and platelet exposure, reduced length of stay in ICU after surgery, lowered cost of haemostatic therapy and better patient survival.10 Furthermore, a systematic review and analysis published in 2019 indicated that TEG-guided haemostatic therapy could enhance blood product management and improve key patient outcomes, including length of stay, bleeding rate and mortality in elective cardiac and liver surgery and emergency resuscitation.11
Bottom line
TEG and ROTEM® have recently caught much attention from trauma surgeons as a rapid point-of-care assessment of haemostasis, and is generally regarded as an improvement over traditional coagulation tests. The clinical applications of TEG/ROTEM® were also extensively investigated in various clinical aspects, such as the management of coagulopathy in sepsis, gastrointestinal bleeding, neurosurgery, cardiac surgery and obstetrics conditions etc. Goal-directed TEG/ROTEM®-guided treatment protocols allow a fast and more accurate assessment of coagulopathy, help guide haemostatic treatment, avoid unnecessary transfusion and improve survival.
References:
- ROTEM® Analysis Targeted Treatment of Acute Haemostatic Disorders. https://www.ttuhsc.edu/medicine/odessa/internal/documents/ttim-manual/ROTEM®_Analysis.pdf
- Maegele M. The Diagnosis and Treatment of Acute Traumatic Bleeding and Coagulopathy. Dtsch Arztebl Int. 2019 Nov 22;116(47):799-806.
- Gratz J, Güting H, Thorn S, Brazinova A, Görlinger K, Schäfer N, Schöchl H, Stanworth S, Maegele M. Protocolised thromboelastometric-guided haemostatic management in patients with traumatic brain injury: a pilot study. Anaesthesia. 2019 Jul;74(7):883-890.
- Veigas PV, Callum J, Rizoli S, Nascimento B, da Luz LT. A systematic review on the rotational thrombelastometry (ROTEM®®) values for the diagnosis of coagulopathy, prediction and guidance of blood transfusion and prediction of mortality in trauma patients. Scand J Trauma Resusc Emerg Med. 2016 Oct 3;24(1):114.
- Baksaas-Aasen K, Van Dieren S, Balvers K, Juffermans NP, Næss PA, Rourke C, Eaglestone S, Ostrowski SR, Stensballe J, Stanworth S, Maegele M, Goslings JC, Johansson PI, Brohi K, Gaarder C; TACTIC/INTRN collaborators. Data-driven Development of ROTEM® and TEG Algorithms for the Management of Trauma Hemorrhage: A Prospective Observational Multicenter Study. Ann Surg. 2019 Dec;270(6):1178-1185.
- Görlinger K, Pérez-Ferrer A, Dirkmann D, Saner F, Maegele M, Calatayud ÁAP, Kim TY. The role of evidence-based algorithms for rotational thromboelastometry-guided bleeding management. Korean J Anesthesiol. 2019 Aug;72(4):297-322.
- Bugaev N, Como JJ, Golani G, Freeman JJ, Sawhney JS, Vatsaas CJ, Yorkgitis BK, Kreiner LA, Garcia NM, Aziz HA, Pappas PA, Mahoney EJ, Brown ZW, Kasotakis G. Thromboelastography and rotational thromboelastometry in bleeding patients with coagulopathy: Practice management guideline from the Eastern Association for the Surgery of Trauma. J Trauma Acute Care Surg. 2020 Dec;89(6):999-1017.
- Rimaitis M, Bilskienė D, Tamošuitis T, Vilcinis R, Rimaitis K, Macas A. Implementation of Thromboelastometry for Coagulation Management in Isolated Traumatic Brain Injury Patients Undergoing Craniotomy. Med Sci Monit. 2020 Jul 4;26:e922879.
- Baksaas-Aasen K, Gall LS, Stensballe J, Juffermans NP, Curry N, Maegele M, Brooks A, Rourke C, Gillespie S, Murphy J, Maroni R, Vulliamy P, Henriksen HH, Pedersen KH, Kolstadbraaten KM, Wirtz MR, Kleinveld DJB, Schäfer N, Chinna S, Davenport RA, Naess PA, Goslings JC, Eaglestone S, Stanworth S, Johansson PI, Gaarder C, Brohi K. Viscoelastic haemostatic assay augmented protocols for major trauma haemorrhage (ITACTIC): a randomized, controlled trial. Intensive Care Med. 2021 Jan;47(1):49-59.
- Weber CF, Görlinger K, Meininger D, Herrmann E, Bingold T, Moritz A, Cohn LH, Zacharowski K. Point-of-care testing: a prospective, randomized clinical trial of efficacy in coagulopathic cardiac surgery patients. Anesthesiology. 2012 Sep;117(3):531-47.
- Dias JD, Sauaia A, Achneck HE, Hartmann J, Moore EE. Thromboelastography-guided therapy improves patient blood management and certain clinical outcomes in elective cardiac and liver surgery and emergency resuscitation: A systematic review and analysis. J Thromb Haemost. 2019 Jun;17(6):984-994.
|
|
|
|
|
|