WINNIPEG -- A Winnipeg man convicted in connection with the death of his mother plans to take his case to the Supreme Court of Canada after he was handed a harsher sentence Thursday, his lawyer said.

Ronald Siwicki was convicted in 2018 of criminal negligence causing death.

His 89-year-old mother, Elizabeth Siwicki, died after falling from her bed and lying on the floor for weeks, according to court documents.

On Thursday, the Manitoba Court of Appeal overturned Ronald Siwicki’s three-month sentence. Instead, the court sentenced Siwicki to two years in prison, respecting time served, for a sentence that totals 21 months.

“(He’s) devastated, absolutely devastated,” Siwicki’s lawyer Mike Cooke said.

Court documents said Elizabeth fell from her bed on Nov. 21, 2014 and was unable to get up. She remained on the floor, laying in her own feces and urine, for the next 26 days until her death on Dec. 17, 2014. The court documents said Elizabeth died from complications of prolonged immobility and bedsores so severe they went down to her bones.

Ronald Siwicki, who was living with his mother at the time, was not able to lift Elizabeth back in bed and did not get medical help, documents show.

“His mom was a very lovely lady, but a very forceful woman,” Cook said, adding that Siwicki’s mother often told him she never wanted to go to the hospital.

“When she fell out of bed, unfortunately in November of 2014, again she said to him, ‘Don’t call an ambulance, you take care of me.’ And he tried.”

Court documents show Siwicki gave his mother nutritional drinks and water after she fell, saying he did not seek medical attention in order to honour his mother’s wishes.

“Her death was completely preventable,” Justice Janice L. LeMaistre wrote in the appellate court decision. “She was not dehydrated or malnourished and she would have survived with the appropriate care.”

In May, the Crown said Justice Colleen Suche, Siwicki’s sentencing judge, made an error in her assessment of aggravating and mitigating factors, passing an “unfit” sentence.

On Thursday Justices Janice L. LeMaistre and Holly C. Beard agreed, ultimately deciding to extend the sentence.

“In my view, the sentencing judge lost sight of the offence before her and failed to appreciate or give effect to the greater degree of responsibility of the accused,” LeMaistre wrote in the decision to extend Siwicki’s sentence, which was not unanimous.

Justice Michel A. Monnin disagreed with his fellow judges, calling Siwicki’s original sentence “fit and proper.”

It’s because of Justice Monnin’s dissenting judgement that Siwicki has an opportunity to take his case to the Supreme Court of Canada, his lawyer Mike Cook said.

“In Mr. Siwicki’s case, he has what we call an automatic right to appeal, to go to the Supreme Court. Because in our court of appeal, there was a dissenting judgement. So two judges said to boost the sentence, one judge said to keep it the way it was,” Cook said. “There is two things we are going to do. One is we are going to file a notice of appeal to the Supreme Court of Canada, and the second thing we are going to do is seek bail pending appeal.”

Cook said if the appeal is accepted by the Supreme Court, Siwicki should be able to post bail and be released leading up to hearing.

Cook said he is “cautiously optimistic” with the future of Siwicki’s case.

-With files from CTV’s Jon Hendricks