In agonising pain, a man undergoing radiation treatment for throat cancer was so sore he couldn’t swallow pain relief tablets given to him by a nurse.

Instead, medical staff at Auckland City Hospital went about administering morphine via injection over the course of the following days.

What eventuated was a significant morphine overdose, leading to a drop of blood oxygen that left the man with a brain injury so severe he struggled to use his phone or switch TV channels.

The mistake was so bad the country’s watchdog for patients has taken the uncommon step of referring the incident for further investigation and possibly penalty.

According to Deputy Health and Disability Commissioner Dr Vanessa Caldwell, a registered nurse was responsible for the error which occurred in February 2019.

Caldwell’s investigation decision released today said after it was clear the man required injected pain relief, he was hooked up to a syringe driver - a pump that injects morphine at a set rate over a set period.

A total of 85mg of morphine was administered in 24 hours.

Only three of the 20 doses given to the man were co-signed by another nurse, while the required patient checks to be undertaken every four hours occurred just twice over the course of the day.

The next day, the man received further morphine from the syringe driver prescribed by a doctor - 70mg over the following 24 hours.

The decision noted there was generally no recommended maximum dose - it is considered on a case-by-case basis.

At 10.45pm on February 14, a new nursing team took over. The shift was busy, with 10 patients and three nurses.

A nurse referred to in the decision as ‘Nurse B’ didn’t check the driver upon handover. She checked the pump, albeit not fully, at 12am, and twice more during the night.

At around 7am the next day, the same nurse discovered the man was snoring loudly. She consulted with another nurse, who gave evidence that Nurse B had said the breathing was “not looking good” - but Nurse B denied this.

The patient was discovered to have low blood oxygen levels. Nurse B did not document the hypoxic event in her notes.

The man was undergoing radiation treatment for throat cancer at Auckland City Hospital. Photo / Sylvie Whinray

A code red was quickly called by another nurse and the patient was rushed to ICU, suffering from opioid narcosis. He was given naloxone to counter the morphine.

He survived - later returning home where he was almost entirely independent. There were no concerns about his neurological status.

But eventually he began to show signs of confusion, struggling to use his phone or switch TV channels, and having altered speech.

The man’s wife recalled being told the symptoms were typical of a high cocaine/opiate user or someone with carbon monoxide poisoning - neither of which applied to her husband.

After a brain scan in the following weeks, he was eventually diagnosed with post-hypoxic leukoencephalopathy - a rare condition where damage to the protective covering of the nerves causes symptoms days to weeks after hypoxia (a lack of oxygen).

The patient’s wife later complained to the Health and Disability Commissioner.

“He will never be able to go back to work and he is really relying on me which makes it hard for me to do my job.

“He currently has a PEG feeding tube in and I have to come home and do his feeds as he can’t remember how to do them,” the man’s wife said.

“I really feel like Auckland Hospital just dropped us and wasn’t really wanting to help us.”

An internal investigation was later conducted, which found the ward was understaffed and the use of the driver increased the risk of respiratory issues. The chief medical officer at the hospital apologised in September 2020.

Nurse B reflected that it was an overtime shift, and she did not take a break and was exhausted by the time the shift ended.

Lack of policies led to overdose

While mindful of the pressures Nurse B was under during the course of her shift, Caldwell found there were failings on her part.

“In my view, appropriate observations, nursing assessments and monitoring are basic nursing requirements that should have been completed by [Nurse B].

“While one missed set of observations may be explicable when a shift is particularly busy, [Nurse B] undertook only one set of vital signs in the whole shift.”

Caldwell also criticised the nurse for not immediately undertaking an assessment or calling a code red, despite being adequately concerned to warrant fetching another nurse.

Deputy Health and Disability Commissioner Dr Vanessa Caldwell. Photo / Supplied

Caldwell found Nurse B in breach of The Code of Patient Rights.

When it came to the hospital, Caldwell said policies were not clear enough.

“This is evident in the practices followed by staff that were not in line with the expected standard of care.

“Opiates are known to suppress breathing and to affect renal function. The risk for this patient was not monitored adequately,” she said.

A number of recommendations were made to what was then the DHB, now Te Whatu Ora Te Toka Tumai Auckland.

Those included education for nursing staff, consideration for a quick reference guide for management of opioid overdose, and providing the man and his family a formal apology.

For Nurse B, Caldwell recommended the nurse provide a written apology to the man and undertake further training on emergency procedures, local policy on observations, and documentation.

Both Te Whatu Ora Auckland and the nurse have since undertaken steps to prevent a similar incident from occurring in future, the decision said.

Caldwell also took the step of referring the incident to the Director of Proceedings.

“In making this referral, I have had regard to the serious systemic issues that did not reflect recommended practice and fell well below the appropriate standard.”