Doctor's anaesthetic errors fatal

Ron Paterson

An anaesthetist has been severely criticised over failings in treating a woman whose breathing collapsed in hospital and who later died.

"The evidence is overwhelming that Dr B failed to keep her patient safe," says Health and Disability Commissioner Ron Paterson, in a just-released decision on what he calls a "rare emergency" case.

But he did not refer it for possible disciplinary prosecution, he said, because he had held the doctor accountable and no public interest existed in further proceedings for accountability or setting standards.

The doctor was in the "twilight" of her career, retired from medicine two years ago and had suffered a significant physical and psychological toll from the patient's death and the subsequent investigations.

The generally healthy 48-year-old patient, Mrs C - all names are deleted from the decision - had sought medical help for vague abdominal pains.

She was admitted to a private hospital in June 2003 for colonoscopy/gastroscopy - intestinal and stomach investigations using a specialised viewing tube - owing to her iron deficiency and family history of bowel cancer.

She was given general anaesthesia because she was very nervous about the investigations, although a surgeon later advised Mr Paterson that colonoscopy and gastroscopy were in New Zealand generally done under intravenous sedation, which allowed the patient to breathe spontaneously, rather than general anaesthetic.

The internal investigations were abandoned after three attempts to insert a breathing tube all failed. Mrs C was shifted from theatre to a recovery room, where she started gagging on a device called a laryngeal mask airway - a tube and cuff fitted over the voice-box - which the anaesthetist then removed.

The woman's oxygen level fell, she had trouble breathing and became discoloured. She was shifted back into theatre where attempts were made to get oxygen into her lungs and to deal with the collapse of her lungs.

An ear, nose and throat surgeon managed to establish an airway after changing her tracheotomy tube - a tube inserted through the neck into the windpipe for emergency breathing.

Her oxygen level improved and she was transferred to a public hospital intensive care unit.

She began having seizures that could not be controlled with anti-convulsant therapy and, because of the brain injury caused by low oxygen levels, active treatment was withdrawn and she died.

Mr Paterson said Dr B had continued to use nitrous oxide, an anaesthetic gas inhaled with oxygen, despite the woman's falling oxygen level.

"Dr B should have discontinued using the nitrous oxide and ventilated Mrs C with 100 per cent oxygen as soon as Mrs C became hypoxic," Mr Paterson said, citing an anaesthetist-adviser.

There was no evidence Dr B considered the possibility that medicine given to reverse a muscle relaxant drug had had an incomplete effect.

The anaesthetist-adviser said that because of incomplete reversal of the relaxant, Mrs C would have been at risk of breathing difficulties on removal of the laryngeal mask airway, not having enough muscle power for adequate breathing.

Mr Paterson said Dr B should have kept the patient in theatre, thoroughly assessed the muscle relaxant reversal, her ability to breathe, and then whether the laryngeal mask airway could be removed.