Mike: Hello, I'm Mike Clarke, podcast editor at the Cochrane Library. Cochrane is producing a series of reviews to help in the response to the COVID-19 pandemic. Among these, our systematic review of interventions for palliative symptom control in people dying of COVID-19 was published in August 2021. In this podcast, Claire Iannizzi speaks with the lead author, Marike Andreas, both from the University Hospital Cologne in Germany, about the review's findings.

Claire: Hello Marike, first could you tell us about palliative symptom control. What is it and how could it help people dying of COVID-19?

Marike: Hello Claire, thanks for the question. In the review, we defined “palliative symptom control” as interventions that aim to improve the symptoms of people with advanced COVID‐19. Importantly, such interventions cannot “cure” the patient, but they can bring some relief and improve their well-being. For example, patients dying of COVID-19 might feel severe breathlessness or anxiety and there are many interventions that might be used to control such symptoms. These might be drugs, such as opioids, or be non-pharmacological, such as breathing exercises; and it's important to know how effective these interventions are. 

Claire: Thanks, that sounds very interesting. So, what kind of evidence were you looking for?

Marike: We searched for studies from anywhere in the world that included patients with any severity of COVID-19 and we wanted to look inside these for the effects on various patient outcomes, including symptom relief, quality of life, side effects and the satisfaction of patients, their carers and family members. And, although our main interest was in randomised trials, we also planned to include observational studies if we could not find enough trials.

Claire: Great. What evidence did you find? Were there any randomised trials?

Marike: No, we didn't identify any trials when we did our searches in March 2021, but we did find four uncontrolled retrospective cohort studies investigating pharmacological interventions for palliative symptom control in hospitalized patients and patients in nursing homes. In these studies, patients received multimodal pharmacological interventions, for example opioids, neuroleptics and benzodiazepines, to try to relieve symptoms such as delirium, anxiety, pain, audible upper airway secretions, respiratory secretions, nausea and cough. However, there were no studies of non‐pharmacological interventions for palliative symptom control in people with COVID‐19.

Claire: And were you able to find out how effective the pharmacological interventions are?

Marike: Because we didn't identify any randomised trials and the observational studies were so different from each other, we could not do any meta-analyses to get more precise estimates of the effects but we have summarized the results in a Table using visual graphs. This shows that, for all the symptoms studied, most of the interventions were rated as completely or partially effective. 

Claire: That sounds really good. Is it? 

Marike: At first glance it seems like that but there are a few problems with the evidence. First of all, these studies were neither randomised nor controlled, and, secondly, all the outcomes were assessed by treating clinicians or nursing staff who were not blinded to the treatments given to the patient. Because of this, there is a high risk of bias in the findings of all the studies, making us very uncertain about the effects of pharmacological interventions on symptom relief. 

Claire: So, what needs to happen to make things more certain? 

Marike: In the future, when we update this review, it would be great to find controlled studies that investigate the effects of palliative symptom control in COVID-19 patients. We have already identified two ongoing studies that use a controlled design and we will add these into a future update, in the hope that might give us more answers. 

Claire: Thanks very much Marike. If people want to read the review, how can they get hold of it? 

Marike: Thanks Claire. The review's available online and people can find it, and future updates, by going to Cochrane Library dot com and typing in a search for 'palliative symptom control for COVID-19'.