Karen Rowan feared she would die of pain while a surgeon operated when she was fully awake but unable to call out because of an anaesthetic failure.
Dr Rowan, a GP, endured the first half-hour of keyhole surgery to remove her gallbladder fully conscious before the failure of a drug infusion pump was rectified.
She told the Weekend Herald the surgery "hurt a lot", but worse still was the emotional trauma of waiting for it to begin while knowing she would feel everything.
"The emotional side of it at the time was worse than feeling pain. Knowing that they were going to cut and not knowing what that was going to be like, and not knowing if I was going to survive. Thinking of my kids and was I going to be alive at the end of this was the hardest thing," she said yesterday.
"The first umbilical incision, although only a few centimetres long felt like a huge incision across my abdomen.
Even more painful was the pressure of the probes pushing around [inside] my upper abdomen," Dr Rowan wrote in an Australian anaesthesia journal in 2002.
Now, 12 years later, that letter about the treatment she received at Auckland Hospital is credited with triggering an important change at hospitals - the widespread use of brain monitoring machines by anaesthetists when the drug propofol is given to induce unconsciousness.
"Her case is absolutely seminal in changing practice in New Zealand," said Dr Ted Hughes, president of the Society of Anaesthetists, which is hosting an international conference running in Auckland until Tuesday.
"Before her case, people thought it might be a good idea to do cerebral monitoring. After her case there was no argument. We were able to convince [hospital] managers across Auckland and then across New Zealand that this was necessary technology for patient safety."
The monitor measures levels of consciousness via electrodes on the forehead that detect nerve activity in the brain and eye movement. It is used alongside propofol, the blood levels of which cannot be measured, but is not needed when anaesthetic gas is employed because consciousness levels have been correlated with exhaled gas volumes.
A Melbourne expert in anaesthetic awareness, Professor Paul Myles, a speaker at the conference, has estimated the complication affects up to 2 of every 1000 surgical patients. A study by his group reported that "bi-spectral index" brain monitoring reduced the risk of the complication by 82 per cent.
Dr Rowan, who now lives in Wellington, had her gallbladder removed in 2000 after suffering recurrent biliary colic during her second pregnancy.
She was given drugs including morphine for pain, propofol to make her unconscious and a muscle relaxant which in effect paralyses the patient to prevent involuntary reactions from muscles. The pump to inject propofol into Dr Rowan's bloodstream failed to do its job apart from the initial dose, despite its display indicating the proper dose had been infused.
Soon after the anaesthetic drugs began being given to Dr Rowan, she felt unable to breathe when a mask was placed over her face. She tried to scream, but only a "short yell" came out and she could make no further sound. She tried to raise a hand but it moved only a few centimetres, and then not at all. She couldn't move anything, not even her eyes, which were closed.
"It was a wrestle of my mind against the rest of my body. I felt like my mind was thrashing around inside my head every time I tried to move.
"I realised that I was not supposed to be awake at this stage and that the anaesthetist and other medical staff in the operating theatre did not know. I waited for them to respond. I felt so alone." She felt her heart beating fast - and her blood pressure rose sharply.
"I could feel the cool iodine being sponged on to my abdomen. I was terrified as I realised I had sensation and was going to feel the surgery. I was not sure if it would be possible to survive through the pain of a whole operation. I prayed to God.
"I heard the surgeon ask the anaesthetist if he should go ahead and start surgery. I had a split second glimmer of hope as I thought maybe they had realised things were too abnormal to begin the surgery. When the anaesthetist replied 'Yes', my heart sank. I could only lie and wait for the incision." Dr Rowan estimated that after 20 to 30 minutes, the pump fault was found and she was put to sleep.
She woke after the operation crying uncontrollably and was told of the pump failure. She suffered anxiety, nightmares and pain complications. Yesterday, she said she could remember what happened, but "it definitely doesn't affect me like it used to". She had been helped by the anaesthetist's apology, and by "forgiving him and not being angry about it ... humans make mistakes, doctors make mistakes".