Category: Emergency Medicine

Categories : Emergency Medicine Injury & TraumaTags :

Aspirin as Effective as Heparin for Clot Prevention in Bone Fracture Hospitalisation

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Patients hospitalised with fractures typically receive low-molecular-weight heparin to prevent life-threatening blood clots. A new clinical trial, however, found that inexpensive over-the-counter aspirin is just as effective. The findings, published today in the New England Journal of Medicine, may lead surgeons to change their practice and administer aspirin to these patients.

With more than 12 000 patients, the multi-centre randomised clinical trial is the largest trial ever conducted on orthopaedic trauma patients. This multidisciplinary collaboration between orthopaedic surgeons and trauma surgeons points to the importance of evaluating techniques used to prevent post-surgical complications, like blood clots and infections, through high-quality, head-to-head comparison studies.

“Many patients with fractures will likely strongly prefer to take a daily aspirin over receiving injections after we found that both give them similar outcomes for prevention of the most serious outcomes from blood clots,” said the study’s principal investigator Robert V. O’Toole, MD. “We expect our findings from this large-scale trial to have an important impact on clinical practice that may even alter the standard of care.”

Patients who experience fractures that require surgery are at increased risk of developing blood clots, including life-threatening pulmonary embolisms. Current guidelines recommend prescribing low-molecular-weight heparin (enoxaparin) to prevent these clots, although smaller clinical trials in total joint replacement surgery suggested a potential benefit of aspirin as a less-expensive, widely available option.

The study enrolled 12 211 patients with leg or arm fractures that necessitated surgery or pelvic fractures regardless of the treatment. Half were randomised to 30mg of injectable enoxaparin twice daily. The other half received 81mg of aspirin twice daily. Patients were followed for 90 days to measure health outcomes from the two treatments.

The main finding of the study was that aspirin was “non-inferior,” or no worse than low molecular-weight heparin in preventing death from any cause – 47 patients in the aspirin group died, compared with 45 patients in the heparin group. For other important complications, the researchers also found no differences in pulmonary embolisms between the two groups. The incidence of bleeding complications, infection, wound problems, and other adverse events from the treatments was also similar in both groups.

Of all the outcomes studied, the only potential difference noted was in deep vein thrombosis. This condition was relatively uncommon in both groups as it occurred in 2.5% of patients in the aspirin group, and in 1.7% of patients in the heparin group.

“This relatively small difference was driven by clots lower in the leg, which are thought to be of less clinical significance and often do not require treatment,” said study co-principal investigator Deborah Stein, MD, MPH.

“Many patients don’t like giving themselves injections. It’s not fun in terms of giving the actual injection because it burns, and your stomach tends to bruise more easily compared to aspirin,” said Debra Marvel, a 53-year-old from Columbia, MD, who served as a patient advisor on the study. She received Lovenox (low-molecular-weight heparin) after her legs were crushed in a 2015 pedestrian accident, requiring multiple surgeries at the University of Maryland Shock Trauma Center. “Patients also prefer aspirin because Lovenox can be expensive based on insurance.”

“An estimated one million Americans are hospitalised each year with extremity fractures, and this new finding could help prevent potentially fatal blood clots in these patients using a medication that is cheaper and far easier to administer,” said Mark T. Gladwin, MD, Vice President for Medical Affairs, University of Maryland, Baltimore, and the John Z. and Akiko K. Bowers Distinguished Professor and Dean, University of Maryland School of Medicine. “Given these important results, we can expect the guidelines for the prevention of blood clots to be revised to include the option of aspirin for patients with traumatic bone fractures.”

Source: University of Maryland School of Medicine

Categories : Emergency MedicineTags :

Rescue of Mountaineer in Alaska Highlights Key Methods

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A trapped mountaineer survived after enduring 16 frigid hours wedged in a crevasse on a mountain in Alaska. The difficult extraction and subsequent critical care are examined in the journal Wilderness & Environmental Medicine. This compelling case study highlights the distinguishing factors that led to the successful outcome, such as continuing even when survival from severe hypothermia seems impossible.

The mountaineer was wedged about 20 metres deep in the crevasse, waiting 4.5 hours for a rescue team to arrive, followed by an 11.5-hour extrication process. His condition deteriorated and he eventually lost consciousness. Even though the rescue team collectively felt there was little or no chance of survival, they continued rescue efforts until the victim was extricated from the crevasse. He was almost immediately placed in a hypothermia wrap with active warming, loaded onto a rescue helicopter, and transported to a hospital in Fairbanks, Alaska. He was released after 14 days and made a full recovery.

“This case documents the heroic, persistent and expert rescue efforts of a group of people dedicated to saving lives. After conferring with the chief rescuer and chief of medical personnel, we pulled together our collective insights about the challenges of extracting climbers from extremely confined spaces and providing medical care to those who have had extended cold exposure,” explained lead investigator Gordon G. Giesbrecht, PhD, professor at the University of Manitoba.

Their recommendations build on lessons learned from a previously published case study of a helicopter pilot who died after being trapped in an icy crevasse for only four hours. In that paper, Dr Giesbrecht identified the need to develop processes for search and rescue personnel to prevent circum-rescue collapse, which is a complex physiological response to extreme cold that is worsened by improper handling of the patient. He cautioned that rescuers should be trained with the principle that the colder the victim is, the more care is required to perform horizontal extrication as gently as possible. Adding a few minutes for gentle handling and to reposition will not significantly increase cold exposure, but will greatly minimise the chance of rescue collapse.

“Responders should be aware of the causes, symptoms, and prevention of rescue collapse. Training should include techniques for transitioning a victim gently from vertical to a horizontal supine or, for narrower passages, to a lateral decubitus position. Even if a victim has to be hauled up in a vertical position, a simple technique using a sling or rope under the knees allows a simple, gentle and horizontal extrication from the crevasse to the surface,” noted Dr Giesbrecht.

This case emphasised the need to continue extrication and treatment efforts for a cold patient even when survival with hypothermia seems impossible. It also underscored the need for rescue teams to pre-plan equipment and procedures specific to crevasse rescue of potentially cold patients.

This case highlights an important mix of preventive and resuscitative lessons and recommendations regarding crevasse rescue in an isolated location:

  • Urging climbers to rope up for glacier travel in areas with known and possible crevasses.
  • Making sure that any rescuers who descend into crevasses are continuously observed by someone who remains on the surface and has radio contact to call for immediate assistance.
  • Recognizing that respirations are often more easily detected than pulses.
  • Trying unorthodox extrication methods when necessary.
  • Rescue teams deployed for crevasse rescues should carry kits with a pneumatic hammer-chisel (important for extrication), a tripod and winch, a hypothermia wrap made of a sleeping bag and chemical heating blankets, onboard oxygen supply with an adapter that connects to nasal prongs or a patient’s mask, a mechanical chest compression device, an automated external defibrillator, and IV saline with a fluid warmer. The Denali National Park and Preserve mountaineering rangers now include such kits in their rescue aircraft.

The investigators plan to submit a standardised rescue process based on these recommendations for publication after completing field testing in the summer of 2023.

When asked about what he considered the most crucial factor for survival, Dr Giesbrecht stressed that rescuers should never give up even when the patient’s survival with hypothermia seems impossible.

Source:

Categories : Emergency Medicine Substance Use UncategorizedTags :

Carrying Naloxone in EDs Could Save Lives

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In a study published in JAMA Network Open, researchers found that after a visit to the ED, many opioid overdose patients carried naloxone, which helps reverse opioid overdoses, which could save their lives in the event of a future overdose.

About 70% of current overdose deaths in the US involve opioids, which means that many of them could be prevented with naloxone. Naloxone is an opioid antagonist, blocking the effect of opioids in overdoses and able to save lives when used in time. It is easy to carry and use, and studies have demonstrated that laypeople can administer it safely and effectively to reverse overdoses.

However the people most likely to witness an overdose, including opioid users and their friends and relatives, may not be able to easily obtain naloxone. Strategies are needed to increase uptake, carrying, and administration of naloxone, especially among at-risk individuals in the community who may not be engaged in routine health care or with community naloxone distribution efforts.

Many at-risk individuals find themselves in the emergency departments (ED), either because of an overdose or other complications of substance use. The Perelman School of Medicine’s Anish Agarwal, an assistant professor of emergency medicine, and Margaret Lowenstein, an assistant professor of medicine, recently examined the potential for ED visits as a critical, reachable moment to engage high-risk individuals in overdose prevention. The team reached out to at-risk patients prescribed naloxone in the ED to understand whether they had obtained their naloxone during or after their ED visit, whether they were carrying it, and their plans to carry it in the future.

The survey asked patients about their experiences and perceptions following the ED encounter related to accessing, using, and carrying naloxone. Most of the patients did not carry naloxone prior to their ED, yet over a third reported having a personal history of an overdose requiring naloxone, and more than a quarter had used naloxone to reverse an overdose for another person in the past. Approximately half of the patients said that they were carrying naloxone after their ED visit, and two-thirds planned to continue carrying. And of patients not carrying naloxone prior to their ED visit, 54% reported a plan to continue carrying it in the future.

Source: University of Pennsylvania

Categories : Emergency Medicine Injury & TraumaTags :

Injectable Nanoparticles That Could Slow Internal Bleeding

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Photo by Camilo Jimenez on Unsplash

Researchers at MIT have found the ideal size for injectable nanoparticles that could slow traumatic internal bleeding, buying more time for a patient to reach a hospital for further treatment.

In a rat study, the researchers showed that polymer nanoparticles particles in an intermediate size range, (about 150nm in diameter) were the most effective at stopping bleeding. These particles also were much less likely to travel to the lungs or other off-target sites, which larger particles often do. The results were published in ACS Nano.

“With nano systems, there is always some accumulation in the liver and the spleen, but we’d like more of the active system to accumulate at the wound than at these filtration sites in the body,” said senior author Paula Hammond, Professor at MIT.

Nanoparticles that can stop bleeding, also called haemostatic nanoparticles, can be made in a variety of ways. One of the most commonly used strategies is to create nanoparticles made of a biocompatible polymer conjugated with a protein or peptide that attracts platelets, the blood cells that initiate blood clotting.

In this study, the researchers used a polymer known as PEG-PLGA, conjugated with a peptide called GRGDS, to make their particles. Most of the previous studies of polymeric particles to stop bleeding have focused on particles ranging in size from 300–500nm. However, few, if any studies have systematically analysed how size affects the function of the nanoparticles.

“We were really trying to look at how the size of the nanoparticle affects its interactions with the wound, which is an area that hasn’t been explored with the polymer nanoparticles used as haemostats before,” Hong says.

Studies in animals have shown that larger nanoparticles can help to stop bleeding, but those particles also tend to accumulate in the lungs, which can cause unwanted clotting there. In the new study, the MIT team analysed a range of nanoparticles, including small (< 100nm), intermediate (140–220nm), and large (500–650nm).

They first analysed the nanoparticles in the lab to see how how they interacted with platelets in various conditions, to see how well platelets bound to them. They found that, flowing through a tube, the smallest particles bound best to platelets, while the largest particles stuck best to surfaces coated with platelets. However, in terms of the ratio particles to platelets, the intermediate-sized particles were the lowest.

“If you attract a bunch of nanoparticles and they end up blocking platelet binding because they clump onto each other, that is not very useful. We want platelets to come in,” said lead author, Celestine Hong, an MIT graduate student. “When we did that experiment, we found that the intermediate particle size was the one that ended up with the greatest platelet content.”

The researchers injected the different size classes of nanoparticles into mice to see how long they would circulate for, and where they would end up in the body. As with previous studies, the largest nanoparticles tended accumulated in the lungs or other off-target sites.

The researchers then used a rat model of internal injury to study which particles would be most effective at stopping bleeding. They found that the intermediate-sized particles appeared to work the best, and that those particles also showed the greatest accumulation rate at the wound site.

“This study suggests that the bigger nanoparticles are not necessarily the system that we want to focus on, and I think that was not clear from the previous work. Being able to turn our attention to this medium-size range can open up some new doors,” Prof Hammond said.

The researchers now hope to test these intermediate-sized particles in larger animal models, to get more information on their safety and the most effective doses. They hope that eventually, such particles could be used as a first line of treatment to stop bleeding from traumatic injuries long enough for a patient to reach the hospital.

Source: Massachusetts Institute of Technology

Categories : Cardiovascular Disease Emergency MedicineTags :

No Difference Between Paramedics’ Advanced Airway Management Strategies

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Similar outcomes were seen for patients with out-of-hospital cardiac arrest (OHCA) regardless of the advanced airway management strategy used by paramedics, results from the Taiwanese SAVE trial showed.

There was no generally no difference in clinical outcomes between groups that had the initial strategies of endotracheal intubation or supraglottic airway device insertion:

Sustained return of spontaneous circulation (ROSC) two hours after resuscitation: 26.9% vs 25.8%; survival to hospital discharge: 8.5% vs 8.4%; cerebral performance category score ≤ 2: 3.9% vs 4.8%.

Only prehospital ROSC suggested an advantage to standard endotracheal intubation (10.6% vs 6.4%), according to the researchers, whose study was published in JAMA Network Open.

Endotracheal intubation is a difficult procedure to get right. The SAVE paramedics, all experienced in both methods of advanced airway management, employed direct laryngoscopy and achieved a 77% rate of first-attempt airway success with endotracheal intubation (vs 83% with the supraglottic device). Average scene time (18.4 vs 16.9 minutes) and call-to-airway time (15.9 vs 13.9 minutes) were both longer with endotracheal intubation.

“It is unclear whether a stepwise and algorithmic endotracheal intubation training program could reduce the time in the field and the time for advanced airway insertion, and further research is warranted,” the authors said.

For the SAVE trial conducted from 2016 to 2019, researchers randomly split four EMS teams in Taipei into two clusters, each assigned to initial endotracheal intubation or supraglottic i-gel device insertion when responding to OHCAs over a biweekly period. In case the first advanced airway attempt failed, rescue airway management was allowed using a number of techniques.

The 936 OHCA patients in the study had a median age of 77 years, and 60.8% were men.

However, subgroup analysis showed that prehospital ROSC rates favoured endotracheal intubation in patients with nonshockable rhythm, nonpublic collapse, witnessed arrest, call-to-airway time under 14 minutes, and age 77 years or older.

However, different in-hospital management between groups could have affected the results. The two study arms were unequal in size, and the study could have been underpowered because of inaccurate sample size representation at the study outset. However, the researchers lamented that “even if we had realised that the sample size was inadequate at that time, we would not have been able to recruit more cases because of the outbreak of COVID.”

Source: MedPage Today