Fibrinogen contribution to clot strength in patients with sepsis and hematologic malignancies and thrombocytopenia-a prospective, single-center, analytical, cross-sectional study

Background

Patients with hematological malignancies (HM) frequently present thrombocytopenia and higher risk of bleeding. Although transfusion is associated with higher risk of adverse events and poor outcomes, prophylactic transfusion of platelets is a common practice to prevent hemorrhagic complications. Thromboelastometry has been considered a better predictor for bleeding than isolated platelet counts in different settings. In early stages of sepsis, hypercoagulability may occur due to higher fibrinogen levels.

Objectives

To evaluate the behavior of coagulation in patients with HM who develop sepsis and to verify whether a higher concentration of fibrinogen is associated with a proportional increase in maximum clot firmness (MCF) even in the presence of severe thrombocytopenia.

Methods

We performed a unicentric analytical cross-sectional study with 60 adult patients with HM and severe thrombocytopenia, of whom 30 had sepsis (sepsis group) and 30 had no infections (control group). Coagulation conventional tests and specific coagulation tests, including thromboelastometry, were performed. The main outcome evaluated was MCF.

Results

Higher levels of fibrinogen and MCF were found in sepsis group. Both fibrinogen and platelets contributed to MCF. The relative contribution of fibrin was significantly higher (60.5 ± 12.8% vs 43.6 ± 9.7%; P < .001) and that of platelets was significantly lower (39.5 ± 12.8% vs 56.4 ± 9.7%; P < .001) in the sepsis group compared with the control group.

Conclusion

Patients with sepsis and HM presented higher concentrations of fibrinogen than uninfected patients, resulting in greater MCF amplitudes even in the presence of thrombocytopenia.

Nurse-run preanaesthesia assessment clinics: an initiative towards improving the quality of perioperative care at the ambulatory care centre

Introduction

Nurse-run preanaesthesia assessment is well established in ambulatory surgery. However, in the Middle East the implementation of such a service is new and needed careful preparation. Aim of this audit is to assess the feasibility and the quality of preoperative assessments by the specially trained nurses, patient and nurse satisfaction and overall perioperative quality of recovery.

Methods

The nurses were selected and trained first in an accredited programme. Then an implementation period of 3 month was used for them to gain experience. Hereafter, we performed a four-step audit on the quality of preassessment, the patient’s satisfaction, the quality of recovery and adverse events if any. Finally, we also monitored the nurse’s satisfaction of their new advanced role.

Results

The quality of preanaesthesia assessment was high as with 95% compliance to the accepted standards. In the patient satisfaction survey, all 152 patients were either highly satisfied or satisfied with the nurse-run service. The nurses were also highly satisfied and felt that they were either highly or moderately valued. All the patients who were operated at the ambulatory care services were followed up postoperatively by telephone calls which revealed that most of them were highly satisfied. No major or minor adverse events occurred.

Conclusion

Our specially trained nurses perform preoperative assessments on high standard without adverse events, while patient and staff satisfaction is very high. Future projects will focus on reducing the rate of cancellation of surgeries, investigating the cost-effectiveness of this approach as well as training the specialised nurses for paediatric preoperative anaesthesia assessments. This model of care could induce further nurse-run models of care in the Middle East.

Flow controlled ventilation in Acute Respiratory Distress Syndrome associated with COVID-19: A structured summary of a study protocol for a randomised controlled trial

Objectives

This study aims to demonstrate the positive effects on oxygenation of flow-controlled ventilation compared to conventionally ventilated patients in patients suffering from Acute respiratory distress syndrome (ARDS) associated with COVID-19.We define ARDS according to the “Berlin” definition integrating the oxygenation index (P/F ratio), the level of Positive End Expiratory Pressure (PEEP), radiological and clinical findings.

Trial design

This is a prospective, randomized (1:1 ratio), parallel group feasibility study in adult patients with proven COVID-19 associated ARDS.

Participants

All adult patients admitted to the ICU of Hamad Medical Corporation facilities in Qatar because of COVID-19 infection who develop moderate to severe ARDS are eligible. The inclusion criteria are above 18 years of age, proven COVID-19 infection, respiratory failure necessitating intubation and mechanical ventilation, ARDS with a P/F ratio of at least 200mmHg or less and a minimum PEEP 5cmH2O, BMI less 30 kg/ m2. The following exclusion criteria: no written consent, chronic respiratory disease, acute or chronic cardiovascular disease, pregnancy or need for special therapy (prone position and/or Extracorporeal membrane oxygenation).

Intervention and comparator

After randomisation, the group A patients will be ventilated with the test-device for 48 hours. The settings will be started with the pre-existing-PEEP. The upper pressure will be determined to achieve a tidal volume of 6 ml/kg lean body mass, while the respiratory rate will be set to maintain an arterial pH above 7.2.

In group B, the ventilator settings will be adjusted by the attending ICU team in accordance with lung-protective ventilation strategy.

All other treatment will be unchanged and according to our local policies/guidelines.

Main outcomes

The primary end point is PaO2. As this is a dynamic parameter, we will record it every 6-8 hours and analyse it sequentially.

Randomisation

The study team screens the ventilated patients who fulfil the inclusion criteria and randomise using a 1:1 allocation ratio after consenting using a closed envelope method. The latter were prepared and sealed in advance by an independent person.

Blinding (masking)

Due to the technical nature of the study (use of a specific ventilator) blinding is only possible for the data-analysts and the patients.

Numbers to be randomised (sample size)

The sample size calculation based on the assumption of an effect size (change in PaO2) of 1.5 SDS in the primary endpoint (PaO2), an intended power of 80%, an alpha error of 5% and an equal sample ratio results in n=7 patients needed to treat. However, to compensate for dropouts we will include 10 patients in each group, which means in total 20 patients.

Trial Status

The local registration number is MRC-05-018 with the protocol version number 3. The date of approval is 14^th April 2020. Recruitment began 28th May 2020 and is expected to end in September 2020.

Trial registration

The protocol was registered before starting subject recruitment under the title: “Flow controlled ventilation in ARDS associated with COVID-19” in ClinicalTrials.org with the registration number: NCT04399317. Registered on 22 May 2020.

Full protocol

The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.

Anticoagulation in critically ill patients on mechanical ventilation suffering from COVID-19 disease, The ANTI-CO trial: A structured summary of a study protocol for a randomised controlled trial

OBJECTIVES

To assess the effect of anticoagulation with bivalirudin administered intravenously on gas-exchange in patients with COVID-19 and respiratory failure using invasive mechanical ventilation.

TRIAL DESIGN

This is a single centre parallel group, superiority, randomized (1:1 allocation ratio) controlled trial.

PARTICIPANTS

All patients admitted to the Hamad Medical Corporation -ICU in Qatar for COVID-19 associated respiratory distress and in need of mechanical ventilation are screened for eligibility.

INCLUSION CRITERIA

all adult patients admitted to the ICU who test positive for COVID-19 by PCR-test and in need for mechanical ventilation are eligible for inclusion. Upon crossing the limit of D-dimers (1.2 mg/L) these patients are routinely treated with an increased dose of anticoagulant according to our local protocol. This will be the start of randomization.

EXCLUSION CRITERIA

pregnancy, allergic to the drug, inherited coagulation abnormalities, no informed consent.

INTERVENTION AND COMPARATOR

The intervention group will receive the anticoagulant bivalirudin intravenously with a target aPTT of 45-70 sec for three days while the control group will stay on the standard treatment with low-molecular-weight heparins /unfractionated heparin subcutaneously (see scheme in Additional file 1). All other treatment will be unchanged and left to the attending physicians.

MAIN OUTCOMES

As a surrogate parameter for clinical improvement and primary outcome we will use the PaO2/FiO2 (P/F) ratio.

RANDOMISATION

After inclusion, the patients will be randomized using a closed envelope method into the conventional treatment group, which uses the standard strategy and the experimental group which receives anticoagulation treatment with bivalirudin using an allocation ratio of 1:1.

BLINDING (MASKING)

Due to logistical and safety reasons (assessment of aPTT to titrate the study drug) only the data-analyst will be blinded to the groups.

NUMBERS TO BE RANDOMISED (SAMPLE SIZE)

We performed a sample size calculation and assumed the data for P/F ratio (according to literature) is normally distributed and used the mean which would be: 160 and SD is 80. We expect the treatment will improve this by 30%. In order to reach a power of 80% we would need 44 patients per group (in total 88 patients). Taking approximately 10% of dropout into account we will include 100 patients (50 in each group).

TRIAL STATUS

The local registration number is MRC-05-082 with the protocol version number 2. The date of approval is 18th June 2020. Recruitment started on 28^th June and is expected to end in November 2020.

TRIAL REGISTRATION

The protocol is registered before starting subject recruitment under the title: "Anticoagulation in patients suffering from COVID-19 disease. The ANTI-CO Trial" in ClinicalTrials.org with the registration number: NCT04445935 . Registered on 24 June 2020.

FULL PROTOCOL

The full protocol is attached as an additional file, accessible from the Trials website (Additional file 2). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.

Anticoagulation in critically ill patients on mechanical ventilation suffering from COVID-19 disease, The ANTI-CO trial: A structured summary of a study protocol for a randomised controlled trial

OBJECTIVES

To assess the effect of anticoagulation with bivalirudin administered intravenously on gas-exchange in patients with COVID-19 and respiratory failure using invasive mechanical ventilation.

TRIAL DESIGN

This is a single centre parallel group, superiority, randomized (1:1 allocation ratio) controlled trial.

PARTICIPANTS

All patients admitted to the Hamad Medical Corporation -ICU in Qatar for COVID-19 associated respiratory distress and in need of mechanical ventilation are screened for eligibility.

INCLUSION CRITERIA

all adult patients admitted to the ICU who test positive for COVID-19 by PCR-test and in need for mechanical ventilation are eligible for inclusion. Upon crossing the limit of D-dimers (1.2 mg/L) these patients are routinely treated with an increased dose of anticoagulant according to our local protocol. This will be the start of randomization.

EXCLUSION CRITERIA

pregnancy, allergic to the drug, inherited coagulation abnormalities, no informed consent.

INTERVENTION AND COMPARATOR

The intervention group will receive the anticoagulant bivalirudin intravenously with a target aPTT of 45-70 sec for three days while the control group will stay on the standard treatment with low-molecular-weight heparins /unfractionated heparin subcutaneously (see scheme in Additional file 1). All other treatment will be unchanged and left to the attending physicians.

MAIN OUTCOMES

As a surrogate parameter for clinical improvement and primary outcome we will use the PaO2/FiO2 (P/F) ratio.

RANDOMISATION

After inclusion, the patients will be randomized using a closed envelope method into the conventional treatment group, which uses the standard strategy and the experimental group which receives anticoagulation treatment with bivalirudin using an allocation ratio of 1:1.

BLINDING (MASKING)

Due to logistical and safety reasons (assessment of aPTT to titrate the study drug) only the data-analyst will be blinded to the groups.

NUMBERS TO BE RANDOMISED (SAMPLE SIZE)

We performed a sample size calculation and assumed the data for P/F ratio (according to literature) is normally distributed and used the mean which would be: 160 and SD is 80. We expect the treatment will improve this by 30%. In order to reach a power of 80% we would need 44 patients per group (in total 88 patients). Taking approximately 10% of dropout into account we will include 100 patients (50 in each group).

TRIAL STATUS

The local registration number is MRC-05-082 with the protocol version number 2. The date of approval is 18th June 2020. Recruitment started on 28th June and is expected to end in November 2020.

TRIAL REGISTRATION

The protocol is registered before starting subject recruitment under the title: "Anticoagulation in patients suffering from COVID-19 disease. The ANTI-CO Trial" in ClinicalTrials.org with the registration number: NCT04445935 . Registered on 24 June 2020.

FULL PROTOCOL

The full protocol is attached as an additional file, accessible from the Trials website (Additional file 2). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.

A European consensus statement on the use of four-factor prothrombin complex concentrate for cardiac and non-cardiac surgical patients

Modern four-factor prothrombin complex concentrate was designed originally for rapid targeted replacement of the coagulation factors II, VII, IX and X. Dosing strategies for the approved indication of vitamin K antagonist-related bleeding vary greatly. They include INR and bodyweight-related protocols as well as fixed dose regimens. Particularly in the massively bleeding trauma and cardiac surgery patient, four-factor prothrombin complex concentrate is used increasingly for haemostatic resuscitation. Members of the Transfusion and Haemostasis Subcommittee of the European Association of Cardiothoracic Anaesthesiology performed a systematic literature review on four-factor prothrombin complex concentrate. The available evidence has been summarised for dosing, efficacy, drug safety and monitoring strategies in different scenarios. Whereas there is evidence for the efficacy of four-factor prothrombin concentrate for a variety of bleeding scenarios, convincing safety data are clearly missing. In the massively bleeding patient with coagulopathy, our group recommends the administration of an initial bolus of 25 IU.kg^-1 . This applies for: the acute reversal of vitamin K antagonist therapy; haemostatic resuscitation, particularly in trauma; and the reversal of direct oral anticoagulants when no specific antidote is available. In patients with a high risk for thromboembolic complications, e.g. cardiac surgery, the administration of an initial half-dose bolus (12.5 IU.kg^-1 ) should be considered. A second bolus may be indicated if coagulopathy and microvascular bleeding persists and other reasons for bleeding are largely ruled out. Tissue-factor-activated, factor VII-dependent and heparin insensitive point-of-care tests may be used for peri-operative monitoring and guiding of prothrombin complex concentrate therapy.

Surgical intensive care - current and future challenges?

Bjorn Ibsen, an anesthetist who pioneered positive pressure ventilation as a treatment option during the Copenhagen polio epidemic of 1952, set up the first Intensive Care Unit (ICU) in Europe in 1953. He managed polio patients on positive pressure ventilation together with physicians and physiologists in a dedicated ward, where one nurse was assigned to each patient. In that sense Ibsen is more or less the father of intensive care medicine as a specialty and also an advocate of the one-to-one nursing ratio for critically ill patients.

Nowadays, the Surgical Intensive Care Unit (SICU) offers critical care treatment to unstable, severely, or potentially severely ill patients in the perioperative setting, who have life-threatening conditions and require comprehensive care, constant monitoring, and possible emergency interventions. Hence there is one very specific challenge in the surgical setting: the intensivist has to manage the patient flow starting from admission to the hospital through to the operating theater, in the SICU, and postoperatively for the discharge to the ward. In other words, the planning of the resources (most frequently availability of beds) has to be optimized to prevent cancellations of elective surgical procedures but also to facilitate other emergency admissions. SICU intensivists take the role of arbitrators between surgical demand and patient's interests. This means they supervise the safety, efficacy, and workability of the process with respect to all stakeholders. This notion was reported in 2007 when Stawicki and co-workers performed a small prospective study concluding that it appears safe if the dedicated intensivist takes over the role of the last arbitrator supported by a multidisciplinary team.¹

However, demographic changes in many countries during the last few decades have given rise to populations which are more elderly and sicker than before. This impacts on the healthcare system in general but on the intensivist and the ICU team too. In addition, in a society with an increased life expectancy, the balance between treatable disease, outcome, and utilization of resources must be maintained. This fact gains even more importance as patients and their families claim “high end” treatment.

Such a demand is reflected looking at the developments that have taken place over the last 25 years. Mainly, the focus of intensive care medicine was on technical support or even replacement of failing organ systems such as the lungs, the heart, or the kidneys by veno-venous extracorporeal membrane oxygenation (VV-ECMO), veno-arterial ECMO (VA-ECMO), and continuous veno-venous hemofiltration (CVVH) respectively. This means “technical care” became a core capability and expectation of critical care medicine. In parallel, medical treatment became more standardized. For example, lung protective ventilation strategies, early enteral feeding, and daily sedation vacation are part of modern protocols. As a consequence, ventilator time has been reduced and patients therefore develop delirium less frequently. These measures, beside others, are implemented in care bundles to improve the quality of care of patients by the whole ICU team.

The importance of specialty trained teams was already pointed out 35 years ago when Li et al.,² demonstrated in a study performed in a community hospital that the mortality was decreased if an ICU was managed 24/7 by an on-site physician. The association of improved outcomes and presence of a critical care trained physician (intensivist) has been shown in several studies since that time.^3,4,5,6 A modern multidisciplinary critical care team consists at least of an intensivist, ICU nurse, pharmacist, respiratory therapist, physiotherapist, and the primary team physician. Based on clinical needs, the team can be supplemented by oncologists, cardiologists, or other specialties. Again, this approach is supported by research: a recent retrospective cohort study from the California Hospital Assessment and Reporting Taskforce (CHART) on 60,330 patients confirmed the association between improved patient outcome and such a multidisciplinary team.⁷

If such an intensive care team makes a difference, why do not all patients at risk receive advanced ICU-care? It was already demonstrated by Esteban et al., in a prospective study that patients with severe sepsis had a mortality rate of 26% when not admitted to an ICU in comparison to 11% when they were admitted to an ICU.⁸ Meanwhile, we know that early referral is particularly important, because for ischemic diseases the timing appears to make a difference in terms of full recovery.

So, the following questions arise: Should intensive care be rolled out to each ward and physical admission to an ICU or be restricted to special cases only? For this purpose, the so-called “Rapid Response Teams” (RRT) or “Medical Emergency Team” (MET), which essentially are a form of an ICU outreach team, were implemented. The name, composition, or exact role of such team varies from institution to institution and country to country. Alternatively, should all ward staff be educated to recognize sick patients earlier for a timely transfer to a dedicated area? This would mean that ICU-care would be introduced in the ward.

A first attempt to answer this question, whether to deploy critical care resources to deteriorating patients outside the ICU 24/7, was given by Churpek et al.⁹ The success of the rapid response teams could be related to decreased rates of cardiac arrest outside the ICU setting and in-hospital mortality. Interestingly, an analysis of the registry database of the RRT calls in this study showed that the lowest frequency of calls occurred between 1:00 AM to 6:59 AM time period. In contrast, the mortality was highest around 7 AM and lowest during noon hour. This indicates that not simply the availability of such a team makes a difference but also the alertness of the ward-teams is of high importance to identify deteriorating patients in a timely manner. Essentially, this would necessitate ward staff being trained to provide a higher level of care enabling them to better recognize when patients become sicker to avoid a delayed call to the ICU.

Alternatively, a system in which the intensivist plays a major role in daily ward rounds could be beneficial. So, the ward doctor should become an intensivist. However, the latter means the ICU is rolled out across the whole hospital which would consume a huge amount of resources.

Another option would be 24/7 remote monitoring of patients at risk that notifies the intensivist or RRT in case of need. The infrastructure, technology, and manpower to put this in place also has associated costs.

As the demand for ICU care will rise further in the future, intensivists will play an even more important role in the healthcare system that itself is under enormous economic pressure to ensure the best quality of care for critically ill patients. Besides excellent knowledge and hard skills, intensivists need to be team players, communicators, facilitators, and arbitrators to achieve the best results in collaboration with all involved in patient treatment.

Thromboelastometry profile in critically ill patients: A single-center, retrospective, observational study

Background

Transfusion therapy is associated with increased morbidity, mortality and costs. Conventional coagulation tests (CCT) are weak bleeding predictors, poorly reflecting coagulation in vivo. Thromboelastometry (ROTEM) provides early identification of coagulation disorders and can guide transfusion therapy by goals, reducing blood components transfusion.

Objective

The aim of this study is to describe coagulation profile of critically ill patients using ROTEM and evaluate the association between CCT and thromboelastometry.

Methods

This is a retrospective, observational study conducted in medical-surgical intensive care unit (ICU). Adult patients (≥18 years) admitted to ICU between November 2012 and December 2014, in whom ROTEM analyses were performed for bleeding management were included in this study. The first ROTEM and CCT after ICU admission were recorded simultaneously. Additionally, we collected data on blood components transfusion and hemostatic agents immediately after laboratory tests results.

Results

The study included 531 patients. Most ROTEM tests showed normal coagulation profile [INTEM (54.8%), EXTEM (54.1%) and FIBTEM (53.3%)] with divergent results in relation to CCT: low platelet count (51.8% in INTEM and 55.9% in EXTEM); prolonged aPTT (69.9% in INTEM and 63.7% in EXTEM) and higher INR (23.8% in INTEM and 27.4% in EXTEM). However 16,7% of patients with normocoagulability in ROTEM received platelet concentrates and 10% fresh frozen plasma.

Conclusion

The predominant ROTEM profile observed in this sample of critically ill patients was normal. In contrast, CCT suggested coagulopathy leading to a possibly unnecessary allogenic blood component transfusion. ROTEM test may avoid inappropriate allogeneic blood products transfusion in these patients.