Repurposing a transplant drug for bone growth

The transplant immunosuppressant drug FK506, also known as tacrolimus or Prograf, can stimulate bone formation in both cell culture and animal Read more

Beyond the amyloid hypothesis: proteins that indicate cognitive stability

If you’re wondering where Alzheimer’s research might be headed after the latest large-scale failure of a clinical trial based on the “amyloid hypothesis,” check this Read more

Mother's milk is OK, even for the in-between babies

“Stop feeding him milk right away – just to be safe” was not what a new mother wanted to hear. The call came several days after Tamara Caspary gave birth to fraternal twins, a boy and a girl. She and husband David Katz were in the period of wonder and panic, both recovering and figuring out how to care for them. “A nurse called to ask how my son was doing,” says Caspary, a developmental Read more

algorithms

Life-saving predictions from the ICU

It’s similar to the “precogs” who predict crime in the movie Minority Report, but for sepsis, the deadly response to infection. That’s how Tim Buchman, director of the Emory Critical Care Center, described an emerging effort to detect and ward off sepsis in ICU patients hours before it starts to make their vital signs go haywire.

As landmark clinical studies have documented, every hour of delay in giving someone with sepsis antibiotics increases their risk of mortality. So detecting sepsis as early as possible could save lives. Many hospitals have developed “sniffer” systems that monitor patients for sepsis risk. See our 2016 feature in Emory Medicine for more details.

What Shamim Nemati and his colleagues, including bioinformatics chair Gari Clifford, have been exploring is more sophisticated. A vastly simplified way to summarize it is: if someone has a disorderly heart rate and blood pressure, those changes can be an early indicator of sepsis.* It requires continuous monitoring – not just once an hour. But in the ICU, this can be done. The algorithm uses 65 indicators, such as respiration, temperature, and oxygen levels — not only heart rate and blood pressure. See below.

Example patient graph. Green = SOFA score. Purple = Artificial Intelligence Sepsis Expert (AISE) score. Red = official definition of sepsis. Blue = antibiotics. Black + red = cultures.    Around 4 pm on December 20, roughly 8 hr prior to any change in the SOFA score, the AISE score starts to increase. The top contributing factors were slight changes in heart rate, respiration, and temperature, given that the patient had surgery in the past 12hr with a contaminated wound and was on a mechanical ventilator. Close to midnight on December 21, other factors show abnormal changes. Five hours later, the patient met the Sepsis-3 definition of sepsis.

As recently published in the journal Critical Care Medicine, Nemati’s algorithm can predict sepsis onset – with some false alarms – 4, 8 even 12 hours ahead of time. No predictor is going to be perfect, Nemati says. The paper lays out specificity, sensitivity and accuracy under various timelines. They get to an AUROC (area under receiving operating characteristic) performance of 0.83 to 0.85, which this explainer web site rates as good (B), and is better than any other previous sepsis predictor. Read more

Posted on by Quinn Eastman in Heart, Immunology Leave a comment