Tag: bleeding

Optimal Placement for Bleeding Control Kits for the Public in Disaster Situations

Photo by Camilo Jimenez on Unsplash

In the event of an accident or an attack, members of the public can save lives by performing first aid measures until the arrival of emergency medical services. But those people willing and able to serve as first responders will also need access to first aid equipment.

“There must also be certain equipment available to manage major bleeding. The question then is where this equipment should be placed, so that people who want to help can quickly access bleeding control kits,” says Carl-Oscar Jonson, adjunct senior associate professor at the Department of Biomedical and Clinical Sciences at Linköping University and head of research at the Center for Disaster Medicine and Traumatology in Linköping.

The first recommendations

Until now, there have been no guidelines for where such bleeding control kits should be located to ensure maximal utility. The current study, published in the journal Disaster Medicine and Public Health Preparedness, now contributes research-based recommendations.

“We found that the largest number of lives saved correlated with bleeding control kits being placed in two or more locations on the premises, but most importantly they shouldn’t be placed at entrances. We also concluded that the equipment must be accessible within 90 seconds’ walking distance,” says Anna-Maria Grönbäck, doctoral student at the Department of Science and Technology at Linköping University, who was involved in developing the simulation.

This means that bleeding control kits should not be placed at entrances, which is often the case with automated external defibrillators (AEDs). The reason for this is that they may be difficult to reach in a situation where many people have to be evacuated at once, such as in the case of attack or major accident. According to attack statistics, roughly 20 injured people will need first aid including a bleeding control kit each. It may be helpful to locate bleeding control kits in the same places as clearly marked AEDs, as long as not located at the entrances.

Bomb consequences simulated

The recommendations are based on conclusions reached by the research team by developing a computer-based simulation of an explosion in a large shopping centre with thousands of simultaneous visitors. In their simulation, the researchers have looked at what happens right after an explosion. The majority of the simulated people try to get out of the premises and move towards the exits. Simulated people close to the blast suffer varying degrees of injury and start bleeding.

In the simulation, some individuals help those injured by applying direct pressure to reduce bleeding, or by trying to find equipment. It is a race against time. Depending on how long it takes to get the equipment, the simulated casualty may die from blood loss.

To find the best strategy for the placement of bleeding control kits, the researchers tested four different scenarios in their simulation. They weighed together the outcomes of the many simulated courses of events for each scenario and compared them to understand which placement of equipment saved the largest number of lives.

Source: Linköping University

Shining a New Light on Tranexamic Acid for Trauma Care

A new study from Australia, New Zealand and Germany published in the New England Journal of Medicine raises important questions about the success or otherwise of using tranexamic acid in trauma. 

Tranexamic acid is commonly used to limit bleeding during surgery. However, its usefulness in emergency settings as a pre-emptive strike in life-threatening bleeding has been controversial, and recent studies have provided contradictory results about whether or not it saves lives or causes dangerous blood clotting. 

The Pre-hospital Antifibrinolytics for Traumatic Coagulopathy and Haemorrhage (PATCH-Trauma) Study was designed to solve this dilemma. Led by Monash University and the Australian and New Zealand Intensive Care Society Clinical Trials Group, it is one of the largest clinical trials ever conducted where treatment was given at the roadside, in an ambulance or in a helicopter prior to reaching hospital. 

It involved 1310 severely injured patients treated by 15 ambulance services and 21 trauma centres in Australia, New Zealand and Germany, taking eight years to complete. 

In addition to all the usual care, patients were randomly assigned to receive pre-hospital tranexamic acid or an inactive placebo. The results showed that for every 100 patients allocated to receive tranexamic acid, there were approximately four extra survivors at six months, but all were severely-disabled and highly-dependent on carers. 

The lead investigator, Professor Russell Gruen, now Dean of the College of Health and Medicine at the Australian National University, described this as a landmark study in trauma care. “It shows it’s not enough to find out only whether treatments save lives or not – quality of life and the long-term outcomes of care also matter,” Professor Gruen said.

Monash University Professor Stephen Bernard, Medical Advisor to Ambulance Victoria and lead for the Australian arm of the study, praised the ambulance services involved. “The PATCH-Trauma Study is further proof that ambulance professionals can conduct rigorous clinical trials in very sick patients and in extremely challenging circumstances,” he said. 

As to whether tranexamic acid should be used for trauma patients, Professor Gruen is circumspect. “Because the drug needs to be given before severely injured patients can make an informed decision, further work is needed to see if we can identify patients who are more likely to survive with a favourable functional outcome if they are given tranexamic acid,” he said. “However, the PATCH-Trauma Study gives us confidence that critical care is possible well before patients get to hospital.” 

Source: EurekAlert!

New Microneedle Patch Rapidly Stops Bleeding

Haemostatic microneedle technology can be applied like a typical adhesive bandage to quickly stop bleeding. The biocompatible and biodegradable microneedle arrays (MNAs) on the patch increase its surface contact with blood to accelerate the clotting process and also increase the adhesive properties of the patch via mechanical interlocking to promote wound closure. Credit: Designed by Amir Sheikhi and Reihaneh Haghniaz/Executed by Natan Barros. All Rights Reserved.

In the US, secondary, uncontrolled bleeding from traumatic injury is the leading cause of death from ages one to 46. Amir Sheikhi, assistant professor of chemical engineering and of biomedical engineering at Penn State, has a plan to change that with a novel microneedle patch that can immediately stop bleeding after injury.

He described his technology in a new paper in the journal Bioactive Materials.

“Excessive bleeding is a serious challenge for human health,” Sheikhi said. “With haemorrhaging injuries, it is often the loss of blood – not the injury itself – that causes death. There is an unmet medical need for ready-to-use biomaterials that promote rapid blood coagulation.”

Sheikhi’s haemostatic microneedle technology can be applied like a typical adhesive bandage to quickly stop bleeding. The biocompatible and biodegradable microneedle arrays (MNAs) on the patch increase its surface contact with blood, accelerating the clotting process. The needles also increase the adhesive properties of the patch via mechanical interlocking to promote wound closure.

In vitro, the engineered MNAs reduced clotting time from 11.5 minutes to 1.3 minutes; and in a rat liver bleeding model, they reduced bleeding by more than 90%,” Sheikhi said. “Those 10 minutes could be the difference between life and death.”

The MNA patch is comparable hydrogel technology that is currently used to treat bleeding wounds in hospitals, but hydrogel applications require preparation and medical expertise. The microneedle patch is pre-engineered for immediate application that anyone can use to stop bleeding, Sheikhi said, much like a typical over-the-counter adhesive bandage.

Microneedles – which are already in use to deliver biologics, such as cells or drugs, through the skin or for cosmetic procedures to stimulate collagen production – are tiny, making their application pain-free, according to Sheikhi.

The researchers are now working to commercialise the patch, with more testing plans.

Source: Penn State

With Warfarin, Dropping Aspirin Reduces Bleeding Complications for Some

Red blood cells
Source: Pixabay

Research from Michigan Medicine suggests that, for venous thromboembolism (VTE) or atrial fibrillation (AF) patients without a history of heart disease who are taking warfarin, stopping aspirin use causes their risk of bleeding complications to drop significantly.

For the study, which is published in JAMA Network Open, researchers analysed over 6700 people treated at anticoagulation clinics across Michigan for VTE as well as AF. Patients were treated with warfarin but also took aspirin despite not having history of heart disease.

“We know that aspirin is not a panacea drug as it was once thought to be and can in fact lead to more bleeding events in some of these patients, so we worked with the clinics to reduce aspirin use among patients for whom it might not be necessary,” said senior study author and cardiologist Geoffrey Barnes, MD.

Over the course of the study, aspirin use among patients fell by 46.6%. With aspirin used less commonly, the risk of a bleeding complication dropped by 32.3% – equivalent to preventing one major bleeding event per every 1000 patients who stop taking aspirin.

“When we started this study, there was already an effort by doctors to reduce aspirin use, and our findings show that accelerating that reduction prevents serious bleeding complications which, in turn, can be lifesaving for patients,” said Dr Barnes. “It’s really important for physicians and health systems to be more cognisant about when patients on a blood thinner should and should not be using aspirin.”

Several studies had found concerning links between concurrent use of aspirin and different blood thinners, which prompted this aspirin de-escalation.

One study reported that patients taking warfarin and aspirin for AF and VTE experienced more major bleeding events and had more ER visits for bleeding than those taking warfarin alone. Similar results were seen for patients taking aspirin and direct oral anticoagulants – who were found more likely to have a bleeding event but not less likely to have a blood clot.

“While aspirin is an incredibly important medicine, it has a less widely used role than it did a decade ago,” Dr Barnes said. “But with each study, we are seeing that there are far fewer cases in which patients who are already on an anticoagulant are seeing benefit by adding aspirin on top of that treatment. The blood thinner they are taking is already providing some protection from clots forming.”

For some people, aspirin can be lifesaving. Many patients who have a history of ischaemic stroke, heart attack or a stent placed in the heart to improve blood flow — as well as those with a history of cardiovascular disease — benefit from the medication.

The challenge comes when some people take aspirin without a history of cardiovascular disease and are also prescribed an anticoagulant, said first author Jordan Schaefer, MD.

“Many of these people were likely taking aspirin for primary prevention of heart attack or stroke, which we now know is less effective than once believed, and no one took them off of it when they started warfarin,” Dr Schaefer said. “These findings show how important it is to only take aspirin under the direction of your doctor and not to start taking over-the-counter medicines like aspirin until you review with your care team if the expected benefit outweighs the risk.”

Source: Michigan Medicine – University of Michigan

Eight Factors Predict Gastrointestinal Bleeding Risk after Heart Attack

Using machine learning, researchers at Karolinska Institutet have identified eight primary factors that increase the risk of a common bleeding complication after heart attack.

Some of these factors had been known already, however, the researchers have found additional predictors, such as smoking, blood pressure and blood glucose. The study was published in the European Heart Journal – Cardiovascular Pharmacotherapy.

“If we can identify patients at high risk of upper gastrointestinal bleeding following heart attack, doctors will be able to take prophylactic measures to mitigate this risk,” said the study’s corresponding author Moa Simonsson, deputy consultant at Karolinska University Hospital and doctoral student. “There are, for instance, drugs that combat bleeding complications, gut bacteria tests that can be used on risk groups and other possibilities for personalised treatment for heart attack patients at high risk of bleeding complications.”

Upper gastrointestinal (GI) tract bleeding is one of the most common bleeding complications following acute myocardial infarction. The condition requires a lot of resources to treat, causes considerable suffering and increases mortality risk. Bleeding complications also limit antithrombotic use, which in turn can worsen the cardiovascular prognosis.

Over the past 20 years, a close focus on bleeding has resulted in several strategies for reducing the risk of upper gastrointestinal tract bleeding. However, few studies on this complication include a diverse population of heart attack patients.

For the current study, the researchers sourced data from the national SWEDEHEART registry on almost 150 000 patients with acute myocardial infarction between 2007 and 2016. Approximately 1.5 percent of these patients suffered GI bleeding within a year of their heart attack, and they also had an increased risk of death and stroke.
Several known factors that increase the risk of upper GI tract bleeding were confirmed by the analysis, including low levels of haemoglobin, previous upper GI tract bleeding, age and intensive antithrombotic treatment.

Using an algorithm, the researchers also identified additional risk factors, including smoking, blood pressure, blood glucose and previous treatment for stomach disorders, such as ulcers and acid reflux.

“If you combine traditional statistical models with machine learning methods, you can create unique opportunities to find key risk factors for previously unknown cardiovascular events,” explained co-author Philip Sarajlic, doctoral student at Karolinska Institutet. “This makes it possible for us to make effective use of valuable data from the medical quality registry by taking account of complex relationships between risk factors and outcomes in order to further optimise the current recommendations for patient care.”

The researchers will soon begin a major clinical study to explore the significance of diagnosis and treatment of a common infection in the upper GI tract.

“A pilot study last year showed a two-fold increase in the presence of Helicobacter Pylori in heart attack patients,” said last author Robin Hofmann, researcher and consultant at Karolinska Institutet. “We will now proceed with a large randomized study to ascertain whether a systematic screening of heart attack patients for Hp infection and, where relevant, its treatment, can reduce bleeding complications and improve prognosis after heart attack.”

Source: Karolinska Institute

A New Snake Venom ‘Super Glue’ For Wound Closures

Photo by David Clode on Unsplash
Photo by David Clode on Unsplash

A novel snake venom ‘super glue’ has been developed, that can stop life-threatening bleeding in under a minute.

Over the past 20 years, bioengineer Kibret Mequanint, a professor at the University, has developed an array of biomaterials-based medical devices and therapeutic technologies – some of which are either now licensed to medical companies or are in the advanced stage of preclinical testing.

This latest work focuses on a blood clotting enzyme called reptilase or batroxobin, which is found in the venom of lancehead snakes (Bothrops atrox), which are amongst the most venomous snakes in South America.

Prof Mequanint and the international research team designed a body tissue adhesive that takes advantage of the clotting property of this enzyme, incorporating it into a modified gelatin that can be packaged into a small, handy tube for easy application.

“During trauma, injury and emergency bleeding, this ‘super glue’ can be applied by simply squeezing the tube and shining a visible light, such as a laser pointer, over it for a few seconds. Even a smartphone flashlight will do the job,” said Prof Mequanint.

Compared to the industry gold standard for clinical and field surgeons, clinical fibrin glue, the new tissue sealant has 10 times the adhesive strength to resist detachment or washout from bleeding. The blood clotting time is also much shorter, halving the 90 seconds for fibrin glue to 45 seconds for this new adhesive.

This novel biotechnology could reduce blood loss and save more lives. Tests were performed in models of major bleeding, such as deep skin cuts, ruptured aortae, and severely injured livers.

“We envision that this tissue ‘super glue’ will be used in saving lives on the battlefield, or other accidental traumas like car crashes,” said Prof Mequanint. “The applicator easily fits in first aid kits too.”

Besides its trauma application, the new snake venom ‘super glue’ can be used in surgical wound closures.

The study was published in the journal Science Advances..

“The next phase of study which is underway is to translate the tissue ‘super glue’ discovery to the clinic,” said Prof Mequanint.

Source: University of Western Ontario

Journal information: Guo, Y., et al. (2021) Snake extract–laden hemostatic bioadhesive gel cross-linked by visible light. Science Advances.doi.org/10.1126/sciadv.abf9635.