A 20-year-old man died after a routine circumcision operation when a surgeon "guessed" how much anaesthetic to give him, a court heard.

General surgeon Pravin Chaturbhai Patel was charged with the manslaughter of Andrew Ryan after he was injected with four times the prescribed level of drugs.

Andrew had gone to Shotley Bridge Hospital, in Consett, County Durham, for a routine operation on July 25, 1997.

But he died after Patel, 52, injected him with as much as four times the amount of local anaesthetic he should have been given, a jury was told.

Andrew, who weighed around 21kg, or three-and-a-half stone, suffered from muscular dystrophy and was sent for the op.

Newcastle Crown Court was told that Patel, from Harrow, Middlesex, admitted injecting Andrew with 10 millilitres of 100 per cent lignocaine - the anaesthetic - equating to a 200mg dose.

The jury heard that 200mg was the maximum dose for a healthy adult and that Andrew should have been given a maximum of a 60mg dose.

Outlining the case, prosecutor Jeremy Hill-Baker, said that Mr Patel was guilty of gross negligence after not ascertaining Andrew's weight to calculate the amount of drug he should be given and instead had just taken a "guess".

He said Patel had also not consulted an anaesthetist or Andrew's main medical team at Newcastle General Hospital, and had carried out the procedure himself, despite knowing Andrew had had breathing difficulties in the past.

Mr Hill-Baker said: "Despite Andrew Ryan's obviously severely wasted condition and known past respiratory breathing difficulties, Mr Patel carried out the operation without the assistance of an anaesthetist and made a number of important, and int he event fatal, decisions.

"As a result he gave Andrew Ryan an overdose of local anaesthetic which led to convulsions, respiratory failure and ultimately death.

"Mr Patel did not intend any injury to Andrew Ryan and certainly never wanted or intended to cause his death but, say the prosecution, he is guilty of his unlawful killing.

"What he did amounted to a breach of duty of care towards his patient. The prosecution say so bad a breach of duty to amount to a crime.

"He was grossly negligent and his gross negligence caused his death."

The court heard that Andrew was sent to the hospital by his GP for the minor operation and the surgeon had been told of his breathing problems.

Mr Hill-Baker said that nurses had seen Mr Patel inject 10ml (200mg) of the drug into Andrew with "no significant wastage" before scrubbing for the surgery and injecting another 3.5ml into him.

He said: "He injected, say the crown, a grossly excessive dose of lignocaine."

Mr Hill-Baker said that, according to experts: "In the healthy adult the maximum safe dose for this type of anaesthesia is usually 200mg, 3mg per kilo.

"In emaciated patients the safe dose must be scaled down by at least the proportion to body weight. so, a 20kilo patient should be given no more than 60mg, or 3milliletres of 2 per cent solution."

He added that the amount should also be scaled down for patients with a muscle wasting disease like muscular dystrophy.

Mr Hill-Baker added: "All of the evidence, the prosecution say, points to Andrew Ryan dying from an overdose of lignocaine.

"Moreover, that overdose was as a result of a catalogue of errors amounting to a breach of duty to his patient that caused his death."

And Mr Hill-Baker told the jury: "The prosecution allege these were not acts of mere inadvertence, they were gross errors, each compounding the others."

Patel, of Harrow, Middlesex, denies manslaughter and the trial, expected to last 10 days, continues.