Tag: 29/6/22

Categories : Antibiotics HospitalsTags :

Antibiotic Stewardship and Sepsis Management: Achieving the Best of Both

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Photo by Anna Shvets on Pexels

Lessening sepsis’s deadly effects means quickly recognising its signs and symptoms, and initiating antibiotic treatments, but some experts have wondered whether this may contribute to antibiotic overuse, especially with time-to-treatment performance measures. A new study published in JAMA Internal Medicine showed that it was possible to effectively treat sepsis while engaging in antibiotic stewardship.

The study led by Hallie Prescott, MD, of the University of Michigan Health Division of Pulmonary and Critical Care and Vincent Liu, MD, of Kaiser Permanente Division of Research, looked at data from more than 1.5 million patients from 2013–2018. Patients included came to the emergency department with signs of systemic inflammatory response syndrome (SIRS), which includes increased heart rate, abnormal body temperature, among other signs.

The research team analysed antibiotics use in these patients, including number receiving antibiotics, when treatment started, treatment duration medications and the broadness of spectrum of the antibiotics.

“We showed in the overall cohort, that antibiotic use decreased. There was a slight decrease in the proportion treated within 48 hours, a more impressive decrease in the average number of days of antibiotic treatment, and also a decrease in the use of broad-spectrum antibiotics,” said Dr Prescott.

About half of the people who met the criteria for SIRS received antibiotics within 12 to 48 hours after admission, a practice that decreased slightly over time. At the same time, 30-day mortality, length of hospitalisation, and the development of multi-drug resistant bacteria also decreased.

“This study adds to our national conversation about how to combat sepsis most effectively. It also confirms that we now need to look for new opportunities to mitigate sepsis by finding patients at high risk before they arrive at the hospital, identifying hospitalised patients most likely to benefit from specific treatments, and enhancing their recovery after they survive sepsis,” said Dr Liu.

Dr Prescott agrees: “The pushback has been [time-to-treatment for sepsis] should not be a performance measure because it’s going to cause more harm than good, and I think our data shows it probably does more good than harm. We have shown that 152 hospitals have been able to make improvements in stewardship and sepsis treatment at the same time, contrary to popular belief.”

Source: Michigan Medicine – University of Michigan

Categories : Implants and Prostheses Metabolic DisordersTags :

A Soft Robotic Design for Diabetic Amputee Pain Relief

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Proof-of-concept rendering (left) and photo (right) of the prototype of the new microfluidics-enabled soft robotic prosthesis for lower limb amputees.
Credit: Waterloo Microfluidics Laboratory at University of Waterloo

Diabetic amputations often involve neuropathy, and patients detect damage resulting from an ill-fitting prosthesis, leading to further amputation. To solve this, in Biomicrofluidics, scientists described a new type of prosthetic using microfluidics-enabled soft robotics that reduces skin ulcerations and pain in patients who have had an amputation between the ankle and knee.

More than 80% of lower-limb amputations are due to diabetic foot ulcers, and the lower limb is known to swell at unpredictable times, resulting in volume changes of 10% or more.

Typically, the prosthesis used after amputation includes fabric and silicone liners that can be added or removed to improve fit. The amputee needs to manually change the liners, but neuropathy leading to poor sensation makes this difficult and can lead to more damage to the remaining limb.

“Rather than creating a new type of prosthetic socket, the typical silicon/fabric limb liner is replaced with a single layer of liner with integrated soft fluidic actuators as an interfacing layer,” said author Carolyn Ren, from the University of Waterloo. “These actuators are designed to be inflated to varying pressures based on the anatomy of the residual limb to reduce pain and prevent pressure ulcerations.”

The scientists started off with pneumatic actuators to adjust the pressure of the prosthetic socket, but it was quite heavy.

To reduce weight, the group miniaturised the actuators, designing a microfluidic chip with 10 integrated pneumatic valves to control each actuator. The full system is controlled by a miniature air pump and two solenoid valves that provide air to the microfluidic chip. The control box is small and light enough to be worn as part of the prosthesis.

Prosthetics experts provided a detailed map of desired pressures for the prosthetic socket. The group carried out extensive measurements of the contact pressure provided by each actuator and compared these to the desired pressure for a working prosthesis.

All of the actuators produced the right pressures suggesting the new device will work well in the field, with the next step being a more accurate biological model.

The group plans additional research to integrate pressure sensors directly into the prosthetic liner, perhaps using newly available knitted soft fabric that incorporates pressure sensing material.

Source: American Institute of Physics

Categories : Cardiovascular Disease Surgeries & ProceduresTags :

Post-operative AF Linked to Risk of Hospitalisation for Heart Failure

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Associations between post-operative atrial fibrillation and incident heart failure hospitalisations. Credit: European Heart Journal

A study of over three million patients found that people who develop an atrial fibrillation (AF) after undergoing surgery have an increased risk of subsequent hospitalisation for heart failure.

The study, which is published in the European Heart Journal, showed that the risk of hospitalisation for heart failure among patients who developed AF after surgery increased regardless of whether or not the surgery was for a heart condition.

Among 76 536 patients who underwent heart surgery, 18.8% developed post-operative AF and the risk of hospitalisation for heart failure increased by a third compared to patients who did not develop AF. Among 2 929 854 patients without a history of heart disease who had surgery for non-heart-related conditions, 0.8% developed AF and the risk of hospitalisation for heart failure doubled.

The study’s first author, Dr Parag Goyal, Associate Professor of Medicine at Weill Cornell Medicine, said: “Our study, which to our knowledge is the largest study to date, shows that post-operative atrial fibrillation is associated with future heart failure hospitalisations. This could mean that atrial fibrillation is an important indicator of underlying but not yet detected heart failure; or it could mean that atrial fibrillation itself contributes to the future development of heart failure. While this study could not specifically address which of these mechanisms are at play, our hope is that this study will inspire future work into exploring the underlying mechanism seen in our important findings.

“Regardless of the mechanism, our study shows that post-operative atrial fibrillation is clearly an important entity that merits attention and incorporation into decision making. Most importantly, patients and doctors need to be more vigilant about heart failure symptoms among patients who develop post-operative atrial fibrillation. Those who do develop the condition may require more aggressive treatments for other risk factors for heart failure, such as high blood pressure, diabetes and narrowing of the arteries.”

Post-operative AF occurs in up to 40% of patients undergoing heart surgery and 2% of patients undergoing non-cardiac surgery. Doctors have tended to view it as a benign event, triggered by the stress of the surgery – but evidence is emerging that post-operative AF is linked to longer term problems such as stroke and death from any cause. Until now, there has been limited evidence regarding its association with subsequent heart failure.

For the current, retrospective study, the researchers collected data on hospital health claims from 2016 to 2018, adjusting for factors that could affect the results such as age, sex, race, insurance status, medical history and body mass index.

Study limitations include its observational nature which can only establish association, not causation. The study relies on administrative claims data and medical codes to identify medical conditions; it lacks more detailed information like management strategies for post-operative AF, and on the function and size of the left ventricle, which could affect the likelihood of developing AF.

The researchers hope to conduct further studies to understand the underlying mechanism and to investigate ways of preventing future hospitalisations for heart failure among patients who develop post-operative AF.

The researchers wrote in the conclusion that “In the meantime, clinicians should be aware that POAF [post-operative AF] may be a harbinger of HF.”

In an accompanying editorial, Dr Melissa Middeldorp and Professor Christine Albert, both from the Smidt Heart Institute at Cedars-Sinai, California, USA, write: “These data add to a growing body of literature suggesting that POAF is not just a transient response to surgery but may be reflective of underlying atrial and myocardial structural changes that not only predispose to the acute AF event but to other potentially related adverse cardiovascular events, such as HF hospitalisation.”

They write that further studies are needed for a better understanding of the mechanisms involved in placing people at greater risk of AF and post-operative heart failure is needed in order to reduce hospitalisation and deaths after surgery.

“With a greater understanding of patients’ full risk factor profile, we may advocate for early aggressive intervention at the initial manifestation of POAF, to improve outcomes and reduce rehospitalisation following cardiac and non-cardiac surgery,” they concluded.

Source: European Society of Cardiology

Categories : Diseases, Syndromes and ConditionsTags :

Highly Resistant MRSA Strain in Pigs Can Jump to Humans

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Methicillin-resistant Staphylococcus aureus (MRSA) bacteria. Credit: CDC

A new study published in eLife has found that a highly antibiotic-resistant strain of methicillin resistant Staphylococcus aureus (MRSA) has emerged in livestock in the last 50 years, likely a result of widespread antibiotic use in pig farming.

The strain, CC398, has become the dominant type of MRSA in European livestock in the past fifty years. It is also a growing cause of human MRSA infections.

The study found that CC398 has maintained its antibiotic resistance over decades in pigs and other livestock. And it is capable of rapidly adapting to human hosts while maintaining this antibiotic resistance. Increasing numbers of humans have been infected with the strain.

“Historically high levels of antibiotic use may have led to the evolution of this highly antibiotic resistant strain of MRSA on pig farms,” said Dr Gemma Murray, a lead author of the study.

She added: “We found that the antibiotic resistance in this livestock-associated MRSA is extremely stable – it has persisted over several decades, and also as the bacteria has spread across different livestock species.”

Antibiotic use in European livestock is much lower than it has been in the past. But despite policy changes reducing antibiotic use on pig farms, this strain of MRSA in pigs is unlikely to be impacted because it is so stable.

CC398 is found in a range of livestock but mostly in pigs. Its rise has been particularly evident in Danish pig farms where the proportion of MRSA-positive herds has increased from less than 5% in 2008 to 90% in 2018. MRSA doesn’t cause disease in pigs.

“Understanding the emergence and success of CC398 in European livestock – and its capacity to infect humans – is vitally important in managing the risk it poses to public health,” said Dr Lucy Weinert in the University of Cambridge’s Department of Veterinary Medicine, senior author of the paper.

The success of CC398 in livestock and its ability to infect humans is linked to three mobile genetic elements in the MRSA genome. These are chunks of genetic material that give the MRSA certain characteristics, including its resistance to antibiotics and its ability to evade the human immune system.

The researchers reconstructed the evolutionary history of two particular mobile genetic elements called Tn916 and SCCmec that confer antibiotic resistancein MRSA, and found they have persisted in a stable way in CC398 in pigs over decades. They also persist when CC398 jumps to humans — carrying with them high levels of resistance to antibiotics commonly used in farming.

In contrast, a third mobile genetic element called ?Sa3, which enables the CC398 strain of MRSA to evade the human immune system, was found to have frequently disappeared and reappeared over time, in both human-associated and livestock-associated CC398. This suggests that CC398 can rapidly adapt to human hosts.

“Cases of livestock-associated MRSA in humans are still only a small fraction of all MRSA cases in human populations, but the fact that they’re increasing is a worrying sign,” said Weinert.

Intensification of farming, combined with high levels of antibiotic use in livestock, has led to particular concerns about livestock as reservoirs of antibiotic-resistant human infections.

Zinc oxide has been used for many years on pig farms to prevent diarrhoea in piglets. Due to concerns about its environmental impact and its potential promotion of antibiotic resistance in livestock, the European Union will ban its use from this month. But the authors say this ban may not help reduce the prevalence of CC398 because the genes conferring antibiotic resistance are not always linked to the genes that confer resistance to zinc treatment.

Source: University of Cambridge

Categories : COVIDTags :

Long COVID Cognitive Impairment More Widespread than Thought

On By ModernMedia
Photo by Alex Green on Pexels

Scientists following COVID patients up to 12 months after diagnosis have found that mild cognitive impairment is common even after mild to moderate COVID. The study results, currently in preprint on the medRxiv server awaiting peer review, suggest that cognitive impairment, though barely noticeable, may affect large portions of the global population.

The finding comes as the US Centers for Disease Control reported that up to 1 in 5 Americans experienced at least one symptom that could be attributable to Long COVID.

SARS-CoV-2 is believed to cause lasting cognitive impairment in some cases, though the exact nature of it was not clear. Severe COVID cases risk damage through hypoxia, stroke, as well as the immune and inflammatory response to SARS-CoV-2. Mild to moderate COVID cases are still at risk of brain dysfunction, and cognitive deficits, providing a window into the potential mechanisms of brain injury without the confounding role of severe disease and its complications. Given the large numbers of people who had mild to moderate COVID disease, there would be significant implications for public health.

To assess the effects of the disease, the researchers studied 128 SARS-CoV-2 positive patients, assessing cognition and olfaction at set intervals after COVID diagnosis, along with lung capacity and blood biomarkers including the kynurenine pathway (KP).

After correcting for demographics, mild to moderate cognitive impairment was present in 26% on year post diagnosis, respectively. Overall cognitive performance declined mildly, but was statistically significant. KP metabolites quinolinic acid, 3-hydroxyanthranilic acid, and kynurenine were significantly associated with cognitive decline.

“The immune system reacts first with the virus … tries to basically get rid of the virus,” she said to ABC News. “Then it goes a little bit into overdrive and this overdrive does not fully calm down.”

The KP pathway was seen to be disturbed similarly to the way inflammation is caused by viruses such as HIV.

“I think we’re seeing something a bit akin here, where this low level of inflammation is more and more understood as being able to traffic to the brain, or even being within the brain and affecting those regions of the brain where we process information that demand speed, extra attention and extra cognitive demands,” she explained.

Dr Cysique emphasises that the cognitive decline recorded among most participants in the study is mild and they may not even notice it.

The researchers suggested that as a unique biomarker, the KP offers a potential therapeutic target for COVID-related cognitive impairment.