A baby boy allegedly poisoned by Lucy Letby received two bags of intravenous feed contaminated with insulin, a court heard.
The 32-year-old nurse is accused of attempting to murder the infant by injecting synthetic insulin into his nutrition during a night shift at the Countess of Chester Hospital’s neo-natal unit.
The heart rate of the youngster – referred to as Child F – soared and his blood sugar dropped to a dangerously low level after the prescribed bag containing nutrients was connected to an intravenous line after midnight on August 5, 2015.
His blood sugar levels remained low throughout the following day shift even after the intravenous long line, and the connected bag, had to be replaced after swelling to the infant’s leg.
Child F eventually made a full recovery after a decision to stop giving the nutrients from the second stock bag in the early evening, Manchester Crown Court has heard.
On Wednesday, prosecutor Nick Johnson KC asked expert witness Dr Sandie Bohin: “Did you conduct a careful review of the medical notes and identified the fact that there was material … to suggest that the TPN ( Total Parenteral Nutrition) bag had been changed?”
“Yes,” replied the consultant neonatologist.
Mr Johnson said: “And secondly, it followed, given the blood sugar readings, that two bags must have been contaminated with insulin?”
Dr Bohin said: “Yes, if a new long line is inserted it would be usual practice to throw away the old bag of TPN, change the long line and put up a new bag which would mean insulin would need to have been in two bags.”
Jurors have heard the TPN bags – both prescribed and stock – were kept in a locked fridge in a store room at the unit, along with insulin.
The nursing shift leader would hold a set of keys to the fridge but they would be passed around colleagues as and when they needed access with no log taken.
Dr Bohin told the court that neonatal hypoglycaemia – persistent low blood sugar levels – could be “absolutely devastating”.
She said: “‘Initially babies may become a little unwell, but if left untreated they could go on to have seizures, fall into a coma and subsequently die.
“Neo-natal fits as a result of very low blood sugar are associated with significant brain damage, those children are not normal and go on to have long term neuro-developmental problems.”
Mr Johnson asked another expert witness, consultant paediatrician Dr Dewi Evans: “Have you ever heard of the legitimate administration of insulin by somebody putting it into a bag of feed?”
Dr Evans replied: “No. never happens. Insulin is always given in a 50ml syringe driver.”
Jurors were told that Child F was the only baby who was receiving TPN on the night shift on which he was allegedly poisoned.
Letby is said to have tried to kill Child F less than 24 hours after she allegedly murdered his twin brother, Child E, by injecting air into his bloodstream.
The defendant, originally from Hereford, denies murdering seven babies and the attempted murders of 10 others between June 2015 and June 2016.
The trial continues on Thursday.