Air injection evidence ‘so poor it cannot support Lucy Letby allegations’, court told

Scientific evidence of how nurse Lucy Letby was said to have harmed a number of babies was “so poor” it cannot be “safely used” to support the allegations, a court has heard.

It is claimed Letby, 33, targeted a number of infants at the Countess of Chester Hospital’s neonatal unit by injecting air into their bloodstream.

The prosecution say this caused an air embolism which blocked their blood supply and led to sudden and unexpected collapse, with some proving fatal.

On Tuesday, Ben Myers KC, continued his defence closing speech at Manchester Crown Court and asked the jury of eight women and four men to consider how the theory of air embolus worked in this case.

Try MEN Premium for FREE by clicking here for no ads, fun puzzles and brilliant new features.

He said: “This is meant to be reliable, scientific medical theory, underpinning the most serious allegations.

“At the heart of it are prosecution experts Dr Dewi Evans and Dr Sandie Bohin. They are the ones we say are pushing it and the prosecution rely on it, of course. Neither of them has clinical experience in identifying or treating air embolus.”

He said both had principally relied on a research paper written more than 30 years ago about the effect of air embolism on infants.

That study, said Mr Myers, showed 11% of 53 children had displayed signs of skin discolouration.

In several cases there were “blanching and migrating areas of cutaneous pallor”, the court heard, and in one case there was “bright pink vessels against a generally cyanosed cutaneous background”.

Mr Myers told jurors: “As a basis for conviction for someone of murder and attempted murder it is tenuous in the extreme.”

He added: “That meagre piece of research has carried into guesswork in this