An investigation into the H1N1-related death of a woman at a Richmond, B.C., hospital is looking into whether the hospital missed a key step in treating people with asthma.

All hospitals in B.C. have a simple guideline for treating high-risk patients suspected of having H1N1.

The B.C. College of Physicians says even if patients display only mild symptoms, Tamiflu, an anti-viral drug, should be considered.

Yet, as CTV News first reported this week, 51-year-old Mae Mah, who suffered from chronic asthma and was at high-risk for complications from H1N1, was only treated for her asthma at Richmond Hospital - even though she displayed shortness of breath, sinus congestion and a fever.

"I think it's very negligent on the doctor's part. I don't know why they don't know. They are supposed to be on top of things, on the ball. They should have picked this up," said her fiance, Dave Palen.

Mah had gone to the hospital twice in the 48 hours before her death, and each time she was sent home after being examined by a doctor. On her second visit, she was given Tylenol.

Mah went into cardiac arrest at home and died in the hospital Nov. 1.

Her family later found out she had H1N1.

In an email Thursday, Vancouver Coastal Health said: "There are established protocols in place and there is no reason to believe that those protocols are not working. The current review will seek to find if these protocols were in fact followed in this instance."

Since the H1N1 flu pandemic hit in April, the BC Centre for Disease Control says about 17 percent of the patients admitted to hospital for H1N1 had asthma.

Of the 23 H1N1-related deaths in B.C., two, including Mah, were asthmatic.

Dr. Perry Kendall, B.C.'s provincial health officer, said Thursday that doctors on the frontlines have been "going out of their way to not let cases slip through."

Little comfort for Mah's family.

Mah's daughter, Tiffany Yung, clings to a bear -- the last gift from her mother.

"I am kind of concerned about that doctor. I don't think he should have sent her home twice without Tamiflu or any treatment," she said.

With a report from CTV British Columbia's Leah Hendry.