The man's family had multiple complaints from as early as his admission in August 2017 and throughout his stay to May 2019.
Deputy Commissioner Rose Wall today found there was a lack of accurate assessment and monitoring of the man and as a result he lost weight, developed pressure areas and experienced pain.
When the man was first admitted to Mercy Parklands he had a history of dementia, vascular disease, stroke, muscle weakness, cancer, and nerve damage.
However, he was noted as being independent when moving and repositioning.
Two months later in October 2017 he was transferred to a long-term area and his daughter complained that after that move, his regular walks stopped and he became wheelchair-bound; placed in one all day without a break except for toileting and put to bed about 10pm.
The rest home told HDC the man regularly engaged in a balance exercise group from September to November 2017.
However, by November 2017, his mobility had declined and his participation depended on him being alert with verbal and physical prompts and he was only able to use his upper limbs.
Despite the decline, the man's handling plan remained unchanged from when he was first admitted.
That plan also stayed the same through to September 2018 when it was updated to state he was using a wheelchair for mobility.
The rest home noted the man expressed a wish to walk daily, with support, and that between December 2018 and April 2019 there was a gradual decline in his mobility, and this was attributed to physical changes, including increased sleepiness.
The man's daughter told HDC that from June 2018 her father complained about pain around his buttocks, and that by December 2018 it was more frequent.
She said it was then that he became unable to reposition himself in his wheelchair, and she told staff that he was complaining of pain, but there were no interventions or explanations.
Despite it being looked at by multiple staff, his wounds weren't properly treated until his daughter checked in early April 2019, and found one on each buttock.
The next day, a doctor identified two areas of ulceration on the inner buttocks with "erosion of skin". Photographs were also taken.
He then suffered a skin tear to his left ear and a bruise to his right hand during a hoist transfer but due to conflicting accounts from staff, Wall was unable to determine how it occurred.
The man's daughter also complained about witnessing a healthcare assistant engage with her father in a "loud and aggressive way".
After investigating, Wall said she had "a number of concerns" about the care provided to the man.
"Mr A developed pressure injuries and weight loss that likely would have been preventable had the appropriate measures been implemented in a timely manner.
"Mr A, not least on account of his comorbidities and general state of health, would have benefited from having a comprehensive care plan in place that was regularly reviewed and amended in response to any change in Mr A's presenting symptoms.
"This would have helped to ensure his cares were consistently delivered by all staff."
Multiple staff were involved in the deficiencies in care provided to Mr A, "and these were systemic issues for which the rest home bears responsibility".
Wall recommended Mercy Parklands report back to HDC on its corrective actions, and one healthcare assistant had already provided an apology.
Wall recommended that a second healthcare assistant also provide a written apology to the man.
Mercy Parklands had made multiple changes and improvements, including in areas of assessments, acute concerns, care plans, organisation, pain management, pressure injury prevention, clinical care and human resources.
The HDC findings come the same day as the Herald revealed the Mercy Parklands board would meet this week to decide its future as it loses $100,000/month due to critical staff shortages.
Board chairman Arthur Morris they had "to seriously look at closure if we can't find another way for sustainability".
Mercy Parkland's chief executive Ann Coughlan has been approached for comment about the HDC's findings.
