Novel Laboratory Developed Test using Radiometer Hemoglobin Assay to Detect Plasma Free Hemoglobin in Patients with Cardiogenic Shock on Impella Support
Novel Laboratory Developed Test using Radiometer Hemoglobin Assay to Detect Plasma Free Hemoglobin in Patients with Cardiogenic Shock on Impella Support
Monday, May 20, 2019
Belmont Ballroom 2-3 (The Cosmopolitan of Las Vegas)
Background
Impella® support in patients with cardiogenic shock (CS) may be complicated by hemolysis due to device malposition, which can be detected by plasma free hemoglobin (pfHb) levels. Accurate and rapid detection of pfHb can aid in optimal device repositioning. The standard spectrophotometer-based pfHb assay, while accurate, has an arduous preparation with lengthy result times.
Methods
We developed an innovative, rapid, laboratory developed test (LDT) utilizing a commonly used radiometer analyzer. Blood samples were obtained from patients in CS on Impella support from August to October 2018 for comparison. Plasma samples were then obtained and uniquely run “off-label” on the radiometer’s whole blood Hb assay. These samples were compared to a Catachem® pfHb assay using Perkin-Elmer Lambda 25 UV/VIS Spectrophotometer. Catachem assays are batched and run only during daylight hours due to preparation time.
Results
48 samples were compared using both methods. The novel LDT provided a pfHb result 100% of the time and was obtained in less than 10 minutes. Spectrophotometer results are reported 1 to 12 hours after the sample is acquired. The scatter plot showed a strong positive correlation between the 2 methods, with an R2 of 0.995 (Figure).
Conclusions
Hemolysis can be identified rapidly and accurately with a novel LDT of plasma on a radiometer-based whole blood Hb assay, compared to a standard spectrophotometer pfHb assay. We propose that this novel LDT can aid in time-efficient Impella repositioning, optimizing patient care. Further validation is warranted.
