Cardiac arrest occurs when the heart suddenly and unexpectedly stops beating. Blood stops flowing to the rest of the body, including the brain and other organs, causing the person to lose consciousness. If the blood flow isn’t restored quickly, the patient dies.
Astrid Glimmerveen
PhD research topic: From Coma to Cognitive Recovery: predicting long-term outcomes after cardiac arrest
Work: Neurophysiological Technician at Rijnstate Hospital & PhD candidate in the Clinical Neurophysiology group, Faculty of Science and Technology at the University of Twente
Education: Master’s degree in Psychology, Tilburg University & Bachelor’s degree Neurophysiological Technician, LOI
Originally from: The Netherlands
‘In the Netherlands, about 17.000 people experience cardiac arrest every year,’ says Astrid Glimmerveen, PhD researcher at the UT. ‘Resuscitation skills have improved over the years and many people know how to use CPR and a defibrillator, but the survival rate of cardiac arrest patients is still only about 23%.’
After suffering a cardiac arrest, most patients arrive at the hospital comatose – in a so called ‘postanoxic coma’, describes Glimmerveen who also works in the Rijnstate Hospital in Arnhem. ‘What follows is a period of great uncertainty,’ she says. ‘Not only for the patient but also for the clinicians and for the patient’s loved ones. We never know if the patient will wake up or not, and whether they will have brain damage if they do wake up.’
No treatment
Sadly, brain damage and other complications are rather common in these cases. In fact, about half of the surviving patients develop long-term problems such as memory issues, anxiety, depression, and sleep disorders. These problems, however, aren’t systematically treated.
‘It is recommended to provide the patients with treatments, but it remains unclear what these treatments should be,’ says Glimmerveen. ‘If the patient wakes up, they are sent home with cardiac care, but no or limited follow-up on their cognitive functioning.’
‘Patients often feel they should just be grateful to be alive, which is also sometimes suggested by people around them,’ she adds. ‘But the quality of life is very important. Being physically alive is only half of the story.’
'Being physically alive is only half of the story'
For many patients, the issues following cardiac arrest completely alter their lives, explains the PhD candidate. ‘Their problems are seen as minor issues, but they are not.’ Patients can suffer from cognitive problems affecting memory and attention, experience difficulties returning to work and managing their social life, or they may even undergo complete changes in personality and way of life.
‘You might wake up after the cardiac arrest, but you might not be the same person who you were before, which is hard for you and your family,’ explains Glimmerveen.
Predicting the outcome
As part of her doctoral thesis, Glimmerveen aims to identify which patients are the most at risk of developing problems, so that they can receive adequate therapy. She has worked both with patients who are still in coma and patients who have woken up, following their health and development for over a year after the cardiac arrest.
The researcher has used various clinical neurophysiological measurements such as electro encephalography (EEG) and somato sensory evoked potential (SSEP) in her studies.
‘The SSEP is considered the golden standard to predict if a patient will wake up,’ she explains. ‘During the test, an electric stimulus is applied at the wrist of the patient to measure if the stimulus is registered in the brain. If the electrical pulse cannot be measured at the scalp, the chances of recovery are less than one percent. In such cases, the treatment is stopped because there is no chance of recovering to a normal life.’
However, SSEP can only be used 72 hours after the cardiac arrest. Internationally and specifically the UT, researchers have performed extensive studies towards the predictive role of the EEG. It has since been shown that EEG patterns can be used already 12 hours after the cardiac arrest to identify potential brain damage and predict the outcome of patients.
As a result, using EEG has now become a recommended course of treatment in the Netherlands, but still only 50% of patients can reliably prognosed. Glimmerveen focusses on extension of SSEP measurements and the combination of SSEP and EEG to improve prognostic values.
‘The not knowing part is extremely difficult for family and friends of the patient’
‘Being able to do this is very important, because it provides more clarity for the clinicians and the family,’ stresses the PhD candidate. ‘The not knowing part is extremely difficult for family and friends of the patient.’
Seen and heard
This is something Glimmerveen sees firsthand in her daily job as a technician at the neurophysiology department of the Rijnstate Hospital. ‘I work directly with cardiac arrest patients in the ICU, and I always hope they survive – and that they have no complications -, but you never know. That’s why it’s so important for me to be able to help the family and the healthcare professionals.’
Astrid Glimmerveen hopes that her research will further improve post-cardiac care for patients who experience long-term cognitive problems. ‘I want these patients to be fully seen and heard,’ she says. ‘At this moment, these patients are overlooked even though they experience genuine problems. Once these patients are discharged from the hospital, they are not followed upon, but I want to make sure that they receive the care they need.’
