What is Sepsis?
An infectious disease expert explains how sepsis develops, why catching it early is critical, and the potential for AI to help diagnosis it.
Sepsis often begins with a seemingly minor infection anywhere in the body, from the lungs to the bladder, to a small skin wound. But instead of the infection resolving normally, sometimes bacteria can spill into the bloodstream, and once they start to circulate, the body can mount an extreme and overwhelming immune response. This condition, known as sepsis, can rapidly damage vital organs and become life-threatening if it isn’t treated right away.
“Our body’s immune system has some amazing and effective ways to fight infections, but there are times when it senses that the infection has disseminated into the bloodstream, the immune system goes into an exaggerated, unregulated response,” says Dr. Marcus Pereira, medical director of the transplant infectious diseases program at NewYork-Presbyterian/Columbia University Irving Medical Center. “The cascade that happens is so complex, and it varies between people.”
Each year, at least 1.7 million adults and 18,000 children in the U.S. are diagnosed with sepsis, according to the Centers for Disease Control and Prevention. Despite how common it is, sepsis is frequently misdiagnosed, in part because it can resemble other illnesses. That’s why recognizing symptoms early is critical, says Dr. Pereira.
“Like other infections, sepsis is treatable if you catch it early,” he says. “If you are concerned about an infection, if something doesn't feel right, or it looks more severe than what you normally would expect, that's the moment to seek medical care immediately. Do not just hope that things will get better on their own.”
To learn more about the signs and symptoms of sepsis and the promise of IA in improving early diagnosis and treatment, Health Matters spoke to Dr. Pereira.
What is sepsis?
Sepsis occurs when you have a bacterial infection (anywhere in your body ranging from pneumonia to a urinary tract infection, for example) and the infection spills over into the bloodstream. Once the bacteria get into the bloodstream, it can circulate throughout the entire body, triggering the immune system to go into overdrive and cause damage. Although not everyone with a bloodstream infection develop sepsis, most cases can be serious.
You can go from dealing with a minor infection, to an infection that’s explosive and out of control.
How do you know if you have sepsis? What are the early warning signs?
Sepsis can be subtle and can escalate rapidly, so it’s important to be on the lookout. If you have an infection and experience these symptoms, you should go to the emergency room:
- Fever or shivering
- Pale or clammy skin
- Elevated heart rate
- Shortness of breath
- Dizziness
- Severe weakness
- Extreme pain, discomfort
- New confusion or disorientation
- Not eating or drinking
How is sepsis diagnosed?
First, we look at symptoms and vital signs. Is the patient breathing fast? Is their blood pressure low? Are they confused? Is the oxygen level dropping? Does the patient have a fever? An abnormally low temperature can also be a red flag for sepsis: it’s a sign of dysregulation in the body, especially the immune system.
Second, we evaluate the patient's medical history. Have they had infections before? Are they immunocompromised? Do they have any medical problems? We also do blood work, for white blood cell count and to detect any changes in organs like the kidneys or liver, and may do imaging.
Finally, we put all these data points together in our computer system, and it helps us identify sepsis cases.
What is the treatment for sepsis?
The first line of defense is antibiotics. Most of the time we can find the cause of the infection and the right antibiotics to target the bacteria. One challenge we have with antibiotics is drug resistance. This happens when people take repeated courses of antibiotics for other illnesses and build up resistance to certain drugs.
Treatment of sepsis also involves IV fluids to help maintain blood pressure and supplemental oxygen. In more severe cases, called septic shock, patients might require special medications to help keep the blood pressure at a more sustainable level, called pressors, as well as intubation to have a machine breath for the patients. At the most extreme, patients may require ECMO — an extracorporeal membrane oxygenation machine which takes over the patient’s heart and lung functions.
Sometimes patients need secondary procedures to treat the source of their infection — for example, draining an abscess or having urgent surgery.
What is the difference between sepsis vs septic shock?
Sepsis is treatable – we are usually able to identify the bacteria, and treat it with antibiotics. When the body doesn’t respond to the antibiotics, sepsis can become more threatening, and it transitions into septic shock. When a patient has septic shock, blood pressure drops and organs can fail. The patient will require intensive care.
Is sepsis contagious?
Sepsis is not contagious because it’s usually caused by bacteria living in our bodies.
Is sepsis curable?
Yes, it is curable. Early diagnosis and interventions are essential for curing sepsis.
AI help with identifying and treating sepsis in the futur
I think that this is a prime example where AI could be helpful. In an emergency room, doctors always have several cases keeping their attention. Some look like sepsis, some do not, and they are all serious. There is no standard definition of sepsis, so our workflow is to assume it’s sepsis until there is an obvious alternative diagnosis because the stakes are so high. With more data and AI, we could potentially develop systems to help identify sepsis cases earlier.
Who is at risk of sepsis?
Certain groups are more at risk for sepsis, including:
- Adults age 65 and older. The immune system weakens with age, and many older adults have other medical issues that make them vulnerable.
- People who are immunocompromised – for example a transplant recipient, a person taking medications to treat an autoimmune disease, or a patient getting chemotherapy.
- Hospitalized patients. Sometimes people who are in the hospital dealing with other medical problems can pick up infections because their body is weakened.
- People with chronic diseases, including diabetes, kidney disease, heart disease, or lung disease.
- People with obesity. If an individual’s body mass index (BMI) is over 30 or 35, studies have shown higher rates of sepsis.
Are there certain bacteria that are known triggers for sepsis?
There are some well-known organisms that have been implicated – for example Staphylococcus aureus, known as staph infection, Group A Streptococcus, or strep, and Escherichia coli, E. coli. It could be that these bacteria are just more common in general, or they may have toxins that trigger sepsis. It could be a combination of both.
We have specialists working to identify these bacteria and recognize sepsis early. There is still a lot that we don't know about the deeper aspects of sepsis.
Could AI help with identifying and treating sepsis in the future?
I think that this is a prime example where AI could be helpful. In an emergency room, doctors always have several cases keeping their attention. Some look like sepsis, some do not, and they are all serious. There is no standard definition of sepsis, so our workflow is to assume it’s sepsis until there is an obvious alternative diagnosis because the stakes are so high. With more data and AI, we could potentially develop systems to help identify sepsis cases earlier.
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