A four-year-old died from a “catastrophic bleed” days after having his tonsils out an inquest heard last week.

Oakley Gould went into Lister Hospital in October last year for the routine operation to help his breathing and appeared to be healing well at home when six days later during breakfast he began losing large amounts of blood into his lungs.

His parents Hayley Clark and David Gould of Bedwell Crescent, Stevenage called for an ambulance and paramedics took the boy back to Lister. But doctors were unable to save him after he suffered cardio-respiratory failure.

The surgeon who carried out the operation said the bleeding was a one-in-15,000 chance. Dr Petros Vlastarakos told the inquest at Hatfield on Thursday that he had performed two other similar surgeries that day and following the usual checks after the operation, Oakley was not bleeding.

The inquest heard that the four-year-old had been back to hospital with a temperature and low blood oxygen levels after the operation but was discharged, with no indication of what was to come.

A post-mortem showed the bleeding could have been caused by the healing process.

Pathologist Marian Malone said: “The granulated tissue is all healing and you have the broken surface on top. The tissue is gradually replaced but just at the stage when the damaged tissue is coming off it is possible to have secondary haemorrhage.

“It is typical of how catastrophic haemorrhage happens.”

Dr Vlastarakos said the only way Oakley would have stood a chance of surviving was if the bleeding had happened while he and an anaesthetist had been standing by him with their equipment.

Herts coroner, Edward Thomas said to Oakley’s parents: “The information I was given was he seemed okay and suddenly, during breakfast, he had this catastrophic bleed.

“What happened then will always be with you. I feel so sorry for you because it must have been absolutely awful.

“One of the sad things is that what happened here is extremely rare but not rare to the people who suffer from it, because it happened to you.”

He recorded the four-year-old had died from a recognised late complication from an operative procedure.