The Health and Disability Commissioner has found Te Whatu Ora Taranaki staff failed to recognise a patient had sepsis.
The patient fell ill following overseas cancer treatment in 2019, with her GP referring her to Taranaki Base Hospital's Emergency Department (ED).
Staff did not recognise signs of sepsis until 12 hours after the patient's admission, when she was taken to the High Dependency Unit.
She died a short time later.
Commissioner Dr Vanessa Caldwell expressed her sincere sympathy to the patient's family for their loss.
Failings by hospital staff included a lengthy delay in seeing a doctor, and some vital observations being recorded wrong, she said.
"Despite the woman's blood results and clinical features pointing to sepsis and the need to escalate her care, there were delays by a number of staff in recognising and appropriately responding to the situation," Caldwell said.
"There was no senior doctor meaningfully involved in her care in the first 13 hours of her admission ... on two occasions the woman's care was not escalated in line with Te Whatu Ora's Early Warning Score (EWS) Mandatory Escalation Pathway. The taking of vital signs and observations to calculate the EWS were also poorly adhered to overall.
"There were also shortcomings in the quality of record-keeping by the medical team in the ED and by nursing staff in the ED and on the medical ward, which made it difficult to track her deteriorating condition," she said.
The errors and omissions were a result of many staff missing opportunities to recognise and respond to the woman's serious illness, Caldwell said.
Caldwell acknowledged Te Whatu Ora had made a number of changes since the patient's death, including improving its staff training and education in relation to sepsis and use of EWS, introducing a 24/7 Patients at Risk nursing service and launching a Speaking Up for Patient Safety campaign for staff.
But she found the care "fell significantly below accepted standards" and considered it to be in the public interest to hold Te Whatu Ora accountable for the failure.
The case has been referred to a lawyer to decide if further action is required.