PARIS (AFP) - Covid-19 treatments and improved hospital care have reduced death rates in intensive care by more than a third since the early months of the pandemic, but this progress might be stalling, according to research published Tuesday (Feb 2).

Whereas medical staff in the first wave of the epidemic had few insights to help them tackle the new virus, they now have some effective drugs and therapies for treating severely ill patients.

A large-scale meta-analysis of overall mortality of Covid-19 patients in intensive care units (ICUs) around the world, published in the journal Anaesthesia, found that it had fallen to 36 per cent by October.

An earlier analysis by the same authors found that ICU mortality had fallen from 60 per cent in late March 2020 to 42 per cent at the end of May.

"After our first meta-analysis last year showed a large drop in ICU mortality from Covid-19 from March to May 2020, this updated analysis shows that any fall in mortality rate between June and October 2020 appears to have flattened or plateaued," the authors said.

Researchers looked at data from 52 observational studies involving 43,128 patients.

The studies were from Europe, North America and China - areas included in the earlier analysis - as well as reports from the Middle East, South Asia and Australia.

Pressure from new variants

The authors said that hospitals now have much more knowledge about what works - and what does not.

In particular, medics now can use steroids like dexamethasone to improve the survival chances of seriously ill patients on oxygen support. Strategies for oxygen therapy, fluid therapy and management of blood clotting have all evolved since the early days of the pandemic.

But with several new variants of the coronavirus emerging in the months since the end of their analysis, they said ICUs may come under further pressure.

British scientists recently warned that the variant that emerged there was not only more transmissible, but could also be more deadly.

Peter Horby, who leads the Recovery trial that provided the evidence for the use of dexamethasone, said recently however that the drugs should continue to work equally well with the new variants. This is because they act on the body's immune response, not the virus itself.

Horby, professor of emerging infectious disease at Oxford University, said overall improvements in therapies and treatments have brought down case fatality rates since the first wave and could even "offset any difference with this new variant".