Comparison of Full Blood Count Parameters Using Capillary and Venous Samples in Patients Presenting to the Emergency Department

Abstract

Full blood count (FBC) analysis is a common investigation done in the emergency department (ED). The aim of this study was to determine the accuracy of bedside FBC analysis using capillary blood samples from a finger stab at point of care (POC) compared to a conventional venous blood sample analysis. A total of 314 consecutive patients presenting to the ED were recruited. After consenting, a sample of the patient's venous (V) blood was obtained via venepuncture and sent to the haematology laboratory for analysis as standard practice. This was followed immediately by collection of a capillary (C) blood sample from a finger stab which was analysed at site using an automated FBC analyser at POC. Agreement between the paired samples for blood parameters including the total white cell count, hemoglobin, and platelet count was assessed by the statistical method of Bland and Altman using V sample as the gold standard. The results showed a statistically significant deviation between capillary and venous samples only for platelet counts (P < 0.001) and haemoglobin (P < 0.001). However, the magnitudes of this difference 7.3 × 109/L and 0.5 g/dL respectively, were not clinically significant. The study suggest that the analysis of capillary samples for FBC parameters is a reliable and acceptable alternative to conventional methods with the benefits of being a rapid, convenient, and minimally invasive technique.

Short-term heat acclimation prior to a multi-day desert ultra-marathon improves physiological and psychological responses without compromising immune status

“…White blood cells (WBC) and WBC content (neutrophils, eosinophils, basophils, lymphocytes and monocytes) were measured and corrected for change in plasma volume (∆PV), which was estimated from haemoglobin and haematocrit (Dill & Costill, 1974). Capillary blood sample collection was chosen due to athlete preference, non-invasiveness, reduced discomfort and convenience, and itis a reliable and accurate method (Ponampalam et al, 2012).…”

Performance of a cost‐effective and automated blood counting system for resource‐limited settings operated by trained and untrained users

“…There exists an unresolved conflict in the literature regarding the appropriateness of capillary blood draws vs venous draws for CBC measurements. While some authors have found significant variations in capillary blood , still others have found minimal variation . Indeed capillary blood draws are standard practice when testing neonate blood or other patients for whom standard blood draws are not possible .…”

Comparison of capillary and venous blood in the analysis of concentration and function of leucocyte sub-populations

“…Although erythrocyte related parameters such as haematocrit and haemoglobin concentration, have been found to be significantly higher in capillary samples (Daae et al 1988), leucocyte concentrations have provided conflicting results. Capillary samples have yielded higher (Schalk et al 2007;Yang et al 2001), lower (Bakhmetyev and Agafonova 2002) or not significantly different (Ponampalam et al 2012) results for the concentration of leucocytes when compared to venous samples. Furthermore, analysis of leucocyte sub-populations in capillary samples has also produced diverging results, where lymphocyte concentration (typically 30 % of circulating leucocytes) has been found to be increased (Daae et al 1988), decreased (Hollis et al 2012) or unaltered (Yang et al 2001) in comparison to results obtained from venous samples.…”