As of January this year, Aotearoa New Zealand became just the second country (after Canada) to adopt a groundbreaking new procedure for patients experiencing cardiac arrest.

Known as “double sequential external defibrillation” (DSED), it will change initial emergency response strategies and potentially improve survival rates for some patients.

Surviving cardiac arrest hinges crucially on effective resuscitation. When the heart is working normally, electrical pulses travel through its muscular walls creating regular, co-ordinated contractions.

But if normal electrical rhythms are disrupted, heartbeats can become unco-ordinated and ineffective, or cease entirely, leading to cardiac arrest.

Defibrillation is a cornerstone resuscitation method. It gives the heart a powerful electric shock to terminate the abnormal electrical activity. This allows the heart to re-establish its regular rhythm.

Its success hinges on the underlying dysfunctional heart rhythm and the proper positioning of the defibrillation pads that deliver the shock. The new procedure will provide a second option when standard positioning is not effective.

Using two defibrillators

During standard defibrillation, one pad is placed on the right side of the chest just below the collarbone. A second pad is placed below the left armpit. Shocks are given every two minutes.

Early defibrillation can dramatically improve the likelihood of surviving a cardiac arrest. However, around 20% of patients whose cardiac arrest is caused by “ventricular fibrillation” or “pulseless ventricular tachycardia” do not respond to the standard defibrillation approach. Both conditions are characterised by abnormal activity in the heart ventricles.

DSED is a novel method that provides rapid sequential shocks to the heart using two defibrillators. The pads are attached in two different locations: one on the front and side of the chest, the other on the front and back.

A single operator activates the defibrillators in sequence, with one hand moving from the first to the second. According to a recent randomised trial in Canada, this approach could more than double the chances of survival for patients with ventricular fibrillation or pulseless ventricular tachycardia who are not responding to standard shocks.

The second shock is thought to improve the chances of eliminating persistent abnormal electrical activity. It delivers more total energy to the heart, travelling along a different pathway closer to the heart’s left ventricle.

Evidence of success

New Zealand ambulance data from 2020 to 2023 identified about 1,390 people who could potentially benefit from novel defibrillation methods. This group has a current survival rate of only 14%.

Recognising the potential for DSED to dramatically improve survival for these patients, the National Ambulance Sector Clinical Working Group updated the clinical procedures and guidelines for emergency medical services personnel.

The guidelines now specify that if ventricular fibrillation or pulseless ventricular tachycardia persist after two shocks with standard defibrillation, the DSED method should be administered. Two defibrillators need to be available, and staff must be trained in the new approach.

Though the existing evidence for DSED is compelling, until recently it was based on theory and a small number of potentially biased observational studies. The Canadian trial was the first to directly compare DSED to standard treatment.

From a total of 261 patients, 30.4% treated with this strategy survived, compared to 13.3% when standard resuscitation protocols were followed.

The design of the trial minimised the risk of other factors confounding results. It provides confidence that survival improvements were due to the defibrillation approach and not regional differences in resources and training.

The study also corroborates and builds on existing theoretical and clinical scientific evidence. As the trial was stopped early due to the COVID-19 pandemic, however, the researchers could recruit fewer than half of the numbers planned for the study.

Despite these and other limitations, the international group of experts that advises on best practice for resuscitation updated its recommendations in 2023 in response to the trial results. It suggested (with caution) that emergency medical services consider DSED for patients with ventricular fibrillation or pulseless ventricular tachycardia who are not responding to standard treatment.

Training and implementation

Although the evidence is still emerging, implementation of DSED by emergency services in New Zealand has implications beyond the care of patients nationally. It is also a key step in advancing knowledge about optimal resuscitation strategies globally.

There are always concerns when translating an intervention from a controlled research environment to the relative disorder of the real world. But the balance of evidence was carefully considered before making the decision to change procedures for a group of patients who have a low likelihood of survival with current treatment.

Before using DSED, emergency medical personnel undergo mandatory education, simulation and training. Implementation is closely monitored to determine its impact.

Hospitals and emergency departments have been informed of the protocol changes and been given opportunities to ask questions and give feedback. As part of the implementation, the St John ambulance service will perform case reviews in addition to wider monitoring to ensure patient safety is prioritised.

Ultimately, those involved are optimistic this change to cardiac arrest management in New Zealand will have a positive impact on survival for affected patients.

Vinuli Withanarachchie, PhD candidate, College of Health, Massey University; Bridget Dicker, Associate Professor of Paramedicine, Auckland University of Technology, and Sarah Maessen, Research Associate, Auckland University of Technology

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Dealing with chronic urinary tract infections (UTIs) means facing more than the occasional discomfort. It’s like being on a never ending battlefield against an unseen adversary, making simple daily activities a trial.

UTIs happen when bacteria sneak into the urinary system, causing pain and frequent trips to the bathroom.

Chronic UTIs take this to the next level, coming back repeatedly or never fully going away despite treatment. Chronic UTIs are typically diagnosed when a person experiences two or more infections within six months or three or more within a year.

They can happen to anyone, but some are more prone due to their body’s makeup or habits. Women are more likely to get UTIs than men, due to their shorter urethra and hormonal changes during menopause that can decrease the protective lining of the urinary tract. Sexually active people are also at greater risk, as bacteria can be transferred around the area.

Up to 60% of women will have at least one UTI in their lifetime. While effective treatments exist, about 25% of women face recurrent infections within six months. Around 20–30% of UTIs don’t respond to standard antibiotic. The challenge of chronic UTIs lies in bacteria’s ability to shield themselves against treatments.

Why are chronic UTIs so hard to treat?

Once thought of as straightforward infections cured by antibiotics, we now know chronic UTIs are complex. The cunning nature of the bacteria responsible for the condition allows them to hide in bladder walls, out of antibiotics’ reach.

The bacteria form biofilms, a kind of protective barrier that makes them nearly impervious to standard antibiotic treatments.

This ability to evade treatment has led to a troubling increase in antibiotic resistance, a global health concern that renders some of the conventional treatments ineffective.

Antibiotics need to be advanced to keep up with evolving bacteria, in a similar way to the flu vaccine, which is updated annually to combat the latest strains of the flu virus. If we used the same flu vaccine year after year, its effectiveness would wane, just as overused antibiotics lose their power against bacteria that have adapted.

But fighting bacteria that resist antibiotics is much tougher than updating the flu vaccine. Bacteria change in ways that are harder to predict, making it more challenging to create new, effective antibiotics. It’s like a never-ending game where the bacteria are always one step ahead.

Treating chronic UTIs still relies heavily on antibiotics, but doctors are getting crafty, changing up medications or prescribing low doses over a longer time to outwit the bacteria.

Doctors are also placing a greater emphasis on thorough diagnostics to accurately identify chronic UTIs from the outset. By asking detailed questions about the duration and frequency of symptoms, health-care providers can better distinguish between isolated UTI episodes and chronic conditions.

The approach to initial treatment can significantly influence the likelihood of a UTI becoming chronic. Early, targeted therapy, based on the specific bacteria causing the infection and its antibiotic sensitivity, may reduce the risk of recurrence.

For post-menopausal women, estrogen therapy has shown promise in reducing the risk of recurrent UTIs. After menopause, the decrease in estrogen levels can lead to changes in the urinary tract that makes it more susceptible to infections. This treatment restores the balance of the vaginal and urinary tract environments, making it less likely for UTIs to occur.

Lifestyle changes, such as drinking more water and practising good hygiene like washing hands with soap after going to the toilet and the recommended front-to-back wiping for women, also play a big role.

Some swear by cranberry juice or supplements, though researchers are still figuring out how effective these remedies truly are.

What treatments might we see in the future?

Scientists are currently working on new treatments for chronic UTIs. One promising avenue is the development of vaccines aimed at preventing UTIs altogether, much like flu shots prepare our immune system to fend off the flu.

Another new method being looked at is called phage therapy. It uses special viruses called bacteriophages that go after and kill only the bad bacteria causing UTIs, while leaving the good bacteria in our body alone. This way, it doesn’t make the bacteria resistant to treatment, which is a big plus.

Researchers are also exploring the potential of probiotics. Probiotics introduce beneficial bacteria into the urinary tract to out-compete harmful pathogens. These good bacteria work by occupying space and resources in the urinary tract, making it harder for harmful pathogens to establish themselves.

Probiotics can also produce substances that inhibit the growth of harmful bacteria and enhance the body’s immune response.

Chronic UTIs represent a stubborn challenge, but with a mix of current treatments and promising research, we’re getting closer to a day when chronic UTIs are a thing of the past.

Iris Lim, Assistant Professor, Bond University

This article is republished from The Conversation under a Creative Commons license. Read the original article.