Biphasic aPTT waveform analysis: an early detection marker for sepsis?
Research type
Research Study
Full title
Is the biphasic aPTT waveform on the Sysmex CS2100i automated coagulation analyser an early detection biomarker for sepsis in adult patients on the Critical Care Unit? REC NUMBER: 13/NW/0763
IRAS ID
127199
Contact name
G Dempsey
Contact email
Sponsor organisation
University Hospital Aintree NHS Foundation Trust
Research summary
WHY: Sepsis is a potentially fatal condition, yet diagnosis can be difficult. Early treatment is essential to ensure good prognosis, and to limit inappropriate use of antibiotics.
WHAT: Patients with sepsis are normally treated on the Critical Care Unit. The current gold standard laboratory test for diagnosis of sepsis is the blood culture. This is a timely test that can take days for a result to become available, and has poor specificity.
HOW: As part of their routine care, patients have blood samples taken to monitor their blood clotting – these tests include the activated partial thromboplastin test (aPTT).
WHERE: The samples are sent to the laboratory and results are available within hours. aPTT’s are performed by an automated coagulation (clotting) analyser, using changes in light transmittance to detect an end point. The generated profiles plot change in light transmittance against time, producing a ‘wave-like’ plot (wave form). Automatic electronic check methods exist within the analysers to verify the integrity of all clotting curves, and an ‘error’ flag is generated if the clotting curve does not develop as expected.
WHO: Not all aPTT tests generate an error flag. Abnormal wave forms have been seen in many clinical conditions, and the ‘biphasic’ waveform was initially described by Toh et al (2002). From general observation over time, a particular biphasic error flag - ‘ERE128’ on the Sysmex C2100i analyser which is used at Aintree Hospitals - appears to occur frequently in patients with a clinical diagnosis of sepsis.
The study aim is to investigate whether this error flag could be statistically linked to sepsis, and thus contribute to a more rapid diagnosis in conjunction with pre-existing clinical scoring systems.
REC name
North West - Liverpool Central Research Ethics Committee
REC reference
13/NW/0763
Date of REC Opinion
18 Oct 2013
REC opinion
Favourable Opinion