Vol. 25 • Issue 8 • Page 28
Nanotechnology
That sepsis is expensive is a gross understatement. The financial demands were summed up nicely in a 2015 CDC guest blog by Jim O’Brien, vice president of quality and patient safety at Ohio Health Riverside Methodist Hospital.1 He noted, “Sepsis is the most expensive reason for hospitalization.1 In 2011 (the most recent published data), the U.S. spent $20.3 billion dollars on hospital care for patients with sepsis.2 This means we are spending $55,616,438 on sepsis care in U.S. hospitals every day. An average hospital stay for sepsis costs approximately double a stay for another diagnosis, and the annual rate of growth of sepsis costs in hospitals is three-times the rate for hospital costs overall. Sepsis patients stay in the hospital 75% longer than other patients-impacting the hospital’s ability to move patients out of the emergency department and into hospital beds. Survivors of sepsis are more likely to be discharged to a place other than home after the hospital and suffer readmissions at a high rate, costing approximately $[two billion] per year.”2,3 Additionally, up to 50% of survivors suffer from post-sepsis syndrome (PSS), according to the Sepsis Alliance.4
The figures are alarming. Yet, the most daunting cost of sepsis is found in the human toll. “Sepsis costs a lot of lives,” said Tom Lowery, PhD, chief scientific officer at T2Biosystems. He explained that, because the amount of pathogen found in the blood of a patient with sepsis is often extremely low, it has traditionally required a blood culture method to be detected.
“A culture test relies on taking a blood sample, mixing it with a culture medium and allowing the organism to grow to a sufficiently high level to be detectable-and that can take days to occur,” said Lowery.
He noted that, because blood is a sterile type of solution, there should never be any living pathogen in the bloodstream. “Our body is constantly keeping the pathogens commensal. If bacteria and fungi that live in the body are in the right ‘compartment’-for example, the gut-they are safe. But if they get out into the bloodstream, you’re in trouble. That happens during trauma or when a patient is immune-compromised,” Lowery explained. “Just a little pathogen in the blood can take off and grow, culture in specific areas of the body, form abscesses, etc. With only 3-30 cells of pathogen per teaspoon of blood, a patient is septic and at risk of going into septic shock, with a 20-40% mortality rate.”
While there is indeed an active immune response to such pathogens, patients who suffer from sepsis are often immune-compromised from other issues they are battling, so their immune system may not be able to fight off infection very well.
Faster Detection With Nanotechology
“Nanotechnology is enabling new paradigms of diagnostic testing,” said Lowery, noting that T2 Biosystems’ T2MR nanotechnology allows labs to approach the diagnostic questions differently. “You actually end up having a different paradigm of the implementation of a test in the laboratory and for the clinician.” The test uses particles that have nanocrystals in them, allowing high sensitivity detection.
“It allows us to go directly in the blood and detect the pathogen without the use of a culture,” explained Lowery. This saves time, and labor to aliquot, look under a microscope and figure out if it is a Gram-positive or a Gram-negative bacteria, or yeast; categorize the pathogen; perform a cell culture; susceptibility testing; and other types of characterizations.
How It Works
With the power of nanotechnology, labs can load a blood sample directly onto a cartridge, load it into the instrument and walk away. The result gets recorded directly into the LIS. “There’s no hand-off; there’s no manual recording of results; there’s no tracing between sample transfers-it’s fully automated. Nanotechnology is greatly simplifying the work flow. But more importantly, it is moving us from a blood culture that had 50-60% sensitivity to a test that has a 96% sensitivity and a 99.4% specificity-a completely game-changing test result,” said Lowery. Blood cultures can miss patients if the pathogen level is too low or the patient is already on an antimicrobial, he explained, adding blood culture doesn’t have any internal control mechanism to tell laboratorians that there is an agent inhibiting the pathogen growth.
Nanotechnology of the T2MR detector uses the same physics behind MRI and puts it into a small bench-top instrument. “It utilizes nanoparticles that detect DNA that is present from the pathogens. Our test uses 2 mL of blood on our cartridge. The instrument concentrates that 2 mL down to .05 mL volume-it forms basically a pellet-and the instrument then breaks open the cells of that debris, amplifies the DNA of our target and then our particles detect that target DNA all directly in our original sample matrix; we never purify the target. Nanotechnology lets us detect in this complex sample environment without purification,” detailed Lowery.
Lowery noted, currently, the official menu of T2MR is not as broad as blood culture. Some institutions are using the test primarily to determine if they should put patients on antifungals. Some hospitals put 40% of their high-risk patients on antifungals, yet they carry a very high cost and can have some severe side effects. Plus, overuse is breeding resistance-these yeast pathogens are now not responsive to standard-of-care treatments,” said Lowery. However, these antifungals are needed because of the risk of candidemia, a fungal form of sepsis which exacts a 40% mortality rate. “With nanotechnology, if a test comes back negative, we don’t need to put patients on an antifungal medication. And if a patient in ICU has signs of sepsis, the test can determine what type of antifungal should be used,” Lowery said.
Nanotechnology is enjoying a rapid adoption rate in hospitals across the U.S. and Europe, in large part because the high sensitivity and specificity allows physicians to select the right drug early on. “This is an important development because with sepsis the mortality rate goes up by 8% every hour a patient is not on the right therapy,” said Lowery. “But when you get a patient on the right drug in the first 12 hours, mortality rate drops from 40% to 11-12%.”
And then there is that always-imperative financial piece to consider. “Nanotechnology can impact cost savings,” said Lowery. “Considering the cost of sepsis and the cost of antifungals, we believe, on average, the savings would be about $1,100 in saved costs per tested patient. That computes to a great deal of money in the big picture.”
Valerie Neff Newitt is on staff at ADVANCE. She can be reached at [email protected]
References
1. O’Brien. The cost of sepsis. CDC Safe Health Blog. Available at: http://blogs.cdc.gov/safehealthcare/2015/09/08/the-cost-of-sepsis/
2. Pfuntner et al. Costs for Hospital Stays in the United States. HCUP Statistical Brief #168.
3. Hall et al. Inpatient care for septicemia or sepsis: A challenge for patients and hospitals. NCHS Data Brief, No. 62; June 2011.
4. The Sepsis Alliance, Post-sepsis syndrome. Available at: www.sepsis.org/sepsis/post_sepsis_syndrome
. T2Biosystems, 2TMR technology. Available at: www.t2biosystems.com/t2mr-technology/t2mr-publications/
