Hospital bosses have apologised after a series of failings resulted in the death of a grandfather, who had not been given enough medication.
Jonathan McCarthy was admitted to Tunbridge Wells Hospital at Pembury last August with chest pains before eventually being moved to the specialist diabetes ward, where he remained for several weeks.
An inquest at the Archbishop's Palace in Maidstone heard the 57-year-old, repeatedly told staff on the ward his blood sugar levels were too high and he needed more insulin, but his concerns were routinely dismissed.
His brother, Keith, told the hearing the level of care received was "nowhere near the level he expected" and described the attitude of some staff members as "arrogant".
On October 6, Mr McCarthy, of Bretland Road in Tunbridge Wells, was given an insufficient dose and his blood sugar levels were so high they were described as "off the charts".
However, a communication breakdown meant senior medical staff were not alerted to the growing dangers to his health.
He died in the early hours of the following morning of diabetic ketoacidosis - a complication of diabetes mellitus which stems from a shortage of insulin.
"I find that the trust failed to correctly monitor Mr McCarthy’s blood sugar and ketone testing..." coroner Roger Hatch
Maidstone and Tunbridge Wells NHS Trust (MTW), which runs the hospital, subsequently launched a review and has admitted seven breaches of duty.
These included a failure by nursing staff to administer the correct dose of insulin, to review Mr McCarthy and ensure ketone analysis was done in the 48 hours before his death.
They also admitted there had been inadequate observations, monitoring of blood sugar, nursing care and mechanisms for escalation.
The nurses working in the hours before his death said the shift was particularly busy.
Recording a narrative conclusion, coroner Roger Hatch said: "On the balance of probabilities, I find that the trust failed to correctly monitor Mr McCarthy’s blood sugar and ketone testing.
“There was a failure to administer the correct dosage of insulin and there was inadequate nursing care and a failure to escalate to the medical team when it was clear this should have been done.
“The death was due to the failure of MTW NHS Trust to check frequently for high blood sugar levels or test for ketone, and as a result of no action being taken, he developed diabetic ketoacidosis from which he died.
“May I express my sympathies to the family.”
Mr McCarthy’s wife Amanda, said: “He warned them that if they didn’t give him more insulin, he would go blind, lose his leg, or it would kill him, and that’s what happened. It was disgusting."
Trust bosses said they had learned lessons from the tragedy and new policies were being rolled out across the ward, including a 'traffic light' system to indicate when blood sugar levels are within a safe, medium and dangerous category.
“It’s clear for staff to follow and I think it will improve safety,” said Dr Masud Haq, a consultant in diabetes and endocrinology at the trust.
A spokesman said: “The trust sets itself high standards in the provision of care for patients.
"It is with much regret these standards were not met for Mr McCarthy.
“While no words can adequately address their loss, we will carefully review the inquest’s findings to ensure every lesson has been learned, and that they remain a lasting reminder of how we should always care for our patients."