Evaluation of 3 Point-of-Care Testing Hematology Analyzers for White Blood Count

The HemoScreen hematology point-of-care device is suitable for rapid evaluation of acute leukemia patients

BACKGROUND

Hematological patients, receiving intensive chemotherapy (predominantly acute leukemia patients), have repeated postchemotherapy periods with severe bone marrow suppression. As a result, these patients require regular monitoring of the complete blood counts (CBC) for optimal patient care. To reduce the strain on the patient, there is a need for a point-of-care (POC) hematology device that provides rapid and reliable results both in general and in cytopenic samples and is suitable for outpatient clinics. We evaluated the HemoScreen device for the most used CBC parameter both overall and at the lower range.

METHODS

The HemoScreen was compared with the Sysmex XN-9000 in 206 routine venous samples and 79 capillary bedside samples focusing on white blood cells (WBC), absolute neutrophil count (ANC), red blood cells (RBC), PLT and HGB.

RESULTS

The HemoScreen was less precise compared to the acceptance criteria set for larger and more advanced hematology instrument with a CV% 3.0-3.7 for WBCs, 3.6-8.4 for ANCs, 1.1-1.5 for RBCs, 2.5-4.4 for PLTs, and 1.7-2.3 for HGB. Correlation coefficient for all five parameters for the entire range was r >.95 and r >.90 at lower range for venous and capillary samples. Bias limits were within the CTCAE acceptance limits.

CONCLUSIONS

The HemoScreen provides rapid and accurate test results, for evaluation of WBC, PLT, and HGB, as well as at low concentrations for guiding transfusions and postchemotherapy treatment. The device is easy to operate and can measure both venous and capillary samples. Therefore, the HemoScreen is well suited for smaller outpatient clinics and potentially home use.

Impact of point-of-care testing for white blood cell count on triage of patients with infection in the remote Northern Territory of Australia

In Australia's Northern Territory (NT), acute infections are highly prevalent within Indigenous remote communities and difficulties in diagnosing the aetiology of infection are exacerbated by limited access to diagnostic tests. The objective of this study was to investigate the clinical effectiveness of point-of-care (POC) testing for total and 5-part differential white blood cell (WBC DIFF) counts for the triage of patients with possible acute infection. The HemoCue WBC DIFF POC device was introduced into 13 remote health clinics over a 6 month period. A retrospective clinical audit of patient cases meeting the selection criteria for three acute infections (sepsis, respiratory infection and appendicitis) were examined by four registrars in duplicate; one with POC test results available and the other with POC test results removed to determine if WBC DIFF results changed or assisted in patient triage. The number of changed outcomes provided a preliminary cost-benefit analysis. Sixty (23%) patient cases met the selection criteria for the clinical effectiveness analysis. POC test results changed the triage decision for 24 (41%) patients, of which 20 (34%) led to the prevention of an unnecessary medical retrieval and four (7%) indicated the patient had an acute infection which required a medical retrieval. POC test results assisted decision making for a further 13 (22%) patients. Cost savings related to avoiding unnecessary medical retrievals were estimated to be AU$481,440. Extrapolated NT-wide cost savings are projected to be AU$5.33 million per annum. POC testing for WBC DIFF counts aided clinical decision making for triaging patients with three common acute infections.