Potential length of stay reductions from emergency department use of a point-of-care high-sensitivity cardiac troponin assay: Pilot findings from Australia's first cardiac emergency department

Objective

To compare actual ED length of stay (LOS) using laboratory-based high-sensitivity cardiac troponin I (hs-cTnI) testing with the potential LOS that could result from using point-of-care (POC) hs-cTnI tests.

Methods

Baseline hs-cTnI tests were performed on the same blood sample in the laboratory (Access hsTnI assay) and in the ED (Atellica VTLi POC assay). Actual and potential LOS were compared for patients who were discharged after having a baseline laboratory hs-cTnI test only. Total LOS incorporated time from arrival to blood sample collection, blood sampling to result availability and result availability to discharge. For potential LOS, the blood sampling to result availability time with POC use was fixed at 10 min (2-min preparation and 8-min test-processing). The laboratory blood sampling to result availability time was from blood sample collection to result uploading on the pathology computer system. For the study, it was assumed that this was the only LOS component that would differ with POC use. Invalid POC result rates were monitored.

Results

For 152 patients discharged after having a single baseline laboratory hs-cTnI test, the median actual LOS was 195 (interquartile range [IQR]: 152–319) min, which included a median laboratory blood-sampling-to-result-availability time of 48 (IQR: 41–59) min. The potential LOS from POC use was 157 (IQR: 103–282) min, which included the fixed 10-min blood-sampling-to-result-availability time. The mean actual-potential LOS difference was 43 (95% confidence interval [CI]: 40–46) min. The POC invalid result rate was 11%.

Conclusion

The Atellica VTLi could deliver a mean ED LOS reduction of 43-min per patient for those discharged after a single baseline hs-cTnI test. Use in actual practice and the invalid result rate require further evaluation.