Doctors at Seton Medical Center in Austin are working to keep four flu patients alive with a heart and lung machine known as ECMO (extracorporeal membrane oxygenation).
"It's a technique where we put a large tube into a vein, take blood out, run it through an artificial lung and pump it back into another vein," Dr. Jordan Weingarten with Seton Medical Center Austin explains.
The machine essentially acts as an artificial lung and it's used as a last resort.
Doctors say those four critically ill patients range from their 20s to 50s and were in good health before getting the H1N1 strain of the flu, but all are considered obese and none got a flu shot.
"That was the pattern we saw in 2009 when H1N1 circulated then, it was predominantly these morbidly obese patients that seemed to be more susceptible to a much more severe illness from H1N1," says Dr. Jack Bissett, an infectious disease specialist.
Doctors cannot explain why Central Texas has seen a spike in flu cases. According to health officials, during the second week of December, there were fewer than 200 confirmed cases in Travis, Williamson and Hays counties. Last week that number jumped to more than 400.
Flu activity is high across the state. A flu surveillance report from the CDC shoes that Texas, Louisiana, Mississippi and Alabama all have the highest number of reported flu cases.
Health officials are stressing the importance of getting vaccinated.
"We're finding that this year's vaccine is quite effective," says Dr. Irfan Hydari with Seton Medical Center Emergency Services. "We're seeing the vast majority of the illness out there is the H1N1 from 2009 and that is actually in the vaccine from this year."
Austin mom of three, Cynthia Short, knows just how serious the flu can get.
"I got really, really sick." she told FOX 7. "I was just exhausted and I didn't feel well and I was congested."
Nearly three years ago she was nine months pregnant with her daughter, Savannah, when she contracted the flu and was rushed to the emergency room.
"It was very scary. I remember them waking me up and saying we're going to have an emergency c-section and that's really the last thing I remember for several weeks."
Doctors didn't know if Cynthia would survive and she was put on an ECMO machine for 18 days. "I had X-rays every day to make sure I was getting better and I was miraculously."
After weeks in the hospital she was finally able to meet her baby girl and go home to her family. Cynthia did not receive a flu shot that year and that's why she's sharing her near-death experience.
Health officials say the flu season in Texas typically lasts through February so it's not too late to get vaccinated. It takes about two weeks for the vaccination to be effective.