A premature baby died of a "massive overdose" of glucose following a series of blunders at a leading children's hospital, an inquest heard today.
Poppy Davies was born three months early on Christmas Eve last year, at just 24 weeks' gestation.
The tiny baby was transferred to Great Ormond Street Hospital in London for specialist care after her birth in Basildon, Essex.
As she was recovering from a routine operation in January, she was attached to a machine supplying her with a glucose solution to give her energy.
But the nurse looking after her, who was in training and had spent just three weeks in the hospital's neonatal intensive care unit, failed to set up the equipment properly.
Rebecca Tite also failed to check whether a safety valve was in place.
As as result, instead of being carefully measured, a free flow of glucose entered Poppy's bloodstream and circulated for over an hour.
Her blood glucose levels rose to 20 times the maximum level they should have been, causing "devastating effects" to her body, St Pancras Coroner's Court in central London heard.
Doctors tried to save Poppy's life by giving her insulin but she died on February 1.
Coroner Dr Andrew Reid recorded a narrative verdict outlining the circumstances of five-week-old Poppy's death, but said it was a "tragic accident".
Police investigated the incident but concluded there were no suspicious circumstances.
Speaking after the inquest, Poppy's father David Daly, a fireplace fitter from Grays, Essex, said he hoped the hospital had learned from its mistakes.
He said: "It's heartbreaking, but what can you do. You've just got to carry on fighting."
Poppy's mother, receptionist Karly Davies, was too upset to comment. She wept throughout the inquest and had to leave the court several times because of her distress.
The machine nurses would have preferred to use to give Poppy glucose would have prevented an accidental overdose being given to her, the inquest heard.
That piece of equipment, which delivered substances intravenously, was being used on Poppy but had to be taken away when a five-year-old boy suffering from meningitis needed it urgently.
Both Mrs Tite and Claire Kirk, the senior nurse on duty on January 11, the day of the overdose, failed to check the safety clamp on the syringe drive that was then used to provide glucose.
Mrs Tite told the inquest: "I didn't check the roller clamp because I would always normally put the roller clamp down when I was preparing fluids."
As the device had been incorrectly set up, the glucose from a 500ml storage bag of 12.5% dextrose solution went into Poppy's bloodstream, instead of that being slowly delivered from the 50ml syringe.
The nurses failed to respond to alarms that sounded in the baby's cubicle which could have alerted them to the fatal error, as they were treating her for breathing problems instead.
Dr Reid said these errors contributed to a "domino effect" that ultimately caused the death of the little girl, who weighed just 740g when she died - less than a bag of sugar.
He said: "I have come to the conclusion that this was a tragic accident in the course of her healthcare.
"It reflects a number of features recognised in terms of clinical risk management where there are a number of steps that have not been taken to prevent the outcome occurring.
"A domino effect applies, and the failure of one preventative system leads to another, with the result that, sadly, a fatal overdose of dextrose was given from which Poppy could not recover."
Poppy's blood glucose levels should have been between four and eight millimoles per litre (mmol/L), nurses said.
A blood test carried out by the hospital's laboratory on the evening of January 11, hours after the overdose was given, revealed her blood glucose levels to be 153mmol/L, however.
The flow of glucose to her blood was switched off after 70 minutes when Ms Kirk noticed the line leading from Poppy was attached to the storage bag. She did not realise the significance of the mistake, however, presuming the safety valve was in place.
When Poppy's condition deteriorated that afternoon, tests were carried out using a hand-held glucometer, a device to check blood glucose. But as the maximum level they detect is 20mmol/L they just gave the reading as "high".
A doctor told nurses to check the reading again an hour later, but it was not until the laboratory blood test was carried out that the scale of the problem was realised.
Dr Reid said while giving his verdict: "It is not possible to say on a balance of probability when, after the overdose started, the point of no return was reached.
"This is a very rare occurrence and there is no literature to say what could or should have been done, other than in a child big enough and fit enough, dialysis may be an option."
It is not possible to know if Poppy would have survived had the overdose not been given.
The inquest was told by Dr Sophie Skellett, head of neonatal intensive care at Great Ormond Street Hospital, that approximately 39 of every 100 babies born at 24 weeks' gestation would survive.
She said Poppy had been in a "fairly stable condition" but had already suffered from septicaemia, along with heart and kidney problems, before the overdose.
David Manknell, representing Ms Davies, said she thought more experienced staff should have been looking after her baby, described as one of the sickest on the ward.
He told the coroner: "One of the concerns of Poppy's mother is that the staff responsible may not have been properly experienced."
Mrs Tite, who was undertaking a year-long training course in intensive care, said she had over six years' experience of looking after "very sick children", however.
She has now left Great Ormond Street Hospital, telling the inquest: "I found this incident devastating and distressing and was no longer able to continue my placement there."
The hospital has now changed the way it provides glucose to babies to prevent such a tragedy happening again.