Dengue Patients’ Hemoglobin Concentrations Compared by POC and CBC

Hematocrit monitoring is a crucial tool to guide management in dengue patients. Microhematocrit adjunct with a complete blood count (CBC) to monitor dengue patients were traditionally performed to decrease the frequency of venipuncture. However, microhematocrit is currently less preferred to the point-of-care hemoglobin monitoring tools to measure red cells in other diseases.

A team of medical scientists at the Ramathibodi Hospital (Bangkok, Thailand) evaluated the relationship between hemoglobin measured by point-of-care hemoglobin (POC-Hb) testing and hematocrit measured by the automated method in adult dengue patients. A total of 44 dengue patients were enrolled. Twenty-nine patients (65.9%) were female, with a median age of 31 years (interquartile range 22–41). Of the enrolled patients, 30 (68.2%), 11 (25.0%), and three (6.8%) were classified as dengue without warning signs, with warning signs, and severe dengue, respectively. Seven patients (15.9%) had hemoconcentration, and five patients (11.3%) had bleeding.

The team measured a CBC by Mindray BC-6800Plus (Mindray, Shenzhen, China) at Ramathibodi Hospital, and Sysmex XN-3000 (Sysmex, Kobe, Japan) at Chakri Naruebodindra Medical Institute. POC-Hb testing was performed on capillary blood and read by the HemoCue Hb 201+ (HemoCue AB, Ängelholm, Sweden). POC-Hb testing was conducted by three physicians who were trained on the use of the device. Hemoconcentration was defined by an increase of ≥20% in hematocrit compared with a convalescent value. A total of 216 pairs of POC-Hb and CBC were evaluated.

The investigators reported that the medians of hemoglobin and hematocrit at dengue presentation were 13.8 g/dL and 41.6%, respectively. The medians of mean corpuscular volume (MCV) and platelets were 87.0 fL and 98,500/mm3, respectively. The team found a significant positive correlation was observed between hemoglobin measured by POC-Hb testing and hematocrit measured by an automated CBC. Bland-Altman analysis between hemoglobin measured by POC-Hb testing and an automated CBC showed a bias of -0.43. Using the cutoff of POC-Hb ≥20% as a criteria for hemoconcentration, the sensitivity and specificity of hemoconcentration detected by POC-Hb device were 71.4% and 100.0%, respectively.

The authors concluded that hemoglobin measurement using POC-Hb testing adjunct with CBC monitoring can be used to monitor plasma leakage as well as hemorrhage in dengue patients. The use of POC-Hb testing is less invasive and requires less blood compared to venipuncture for CBC evaluation. The study was published on August 16, 2021 in the journal PLOS Neglected Tropical Diseases.

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Ramathibodi Hospital
Mindray
Sysmex
HemoCue AB