According to the report from the commissioner, the caregiver did not perform the necessary checks, due to "feeling unwell and in a rush". Consequently, the patient was not given her prescribed medications, but was given quetiapine fumarate (an anti-psychotic) and carbamazepine controlled release (an anti-spasmodic), which was prescribed for another client.
Ten minutes after the pills were taken with her evening meal, the woman passed out for about a minute, the report said.
Later that evening, the rehabilitation centre's on-call registered nurse was told that the family had contacted the facility to say that the medication they had given to the woman was meant for another person.
The nurse assessed the woman at the facility, and found her alert, responsive, and conversing.
The nurse took the patient's blood pressure and pulse, both of which were within normal limits, but did not take the her respiration rate or her blood glucose level -- despite the woman not receiving her usual metformin medication and having consumed alcohol.
The nurse remained at the facility until 1.30am, but did not call the emergency department for further advice, or contact the National Poisons Centre.
Instead, the nurse instructed staff to monitor the woman at half-hourly intervals overnight and, if there was any sign of deterioration, they were to arrange for an ambulance.
The commissioner found caregiver in breach of the Code for failing to follow safe medication checking practices.
Mr Hill also found the nurse was in breach of the Code for failing to assess the woman properly and failing to seek appropriate medical advice.
Mr Hill also criticised the documentation surrounding the incident, stating that this could have been clearer and more accurate.
He recommended that the caregiver and nurse provide formal written apologies, and that the rehabilitation service report to the Health and Disability Commission on various matters, including its review of its medication management standard operating procedure, the formal training it has provided to staff on clinical documentation, the establishment of its quality assurance group, and improvements to the client monitoring form and staff compliance with its use.
Mr Hill also recommended that the rehabilitation service conduct a random audit of nurse and caregiver documentation over the last six months and report to Health and Disability Commission on this.