The Lower Pole of the Earlobe is an Alternative Site for Painless Blood Sampling in the Self-assessment of Blood Glucose Concentrations

Abstract

Objectives Measurement of blood glucose is essential for better control of diabetes mellitus. The pain associated with repeated blood sampling is a significant problem, and a less painful technique would be advantageous. This study was conducted to establish a less painful method of blood sampling for monitoring of blood glucose concentrations.Methods Fourteen healthy doctors and nurses at the age of 22 to 32 years were enrolled into this study. The earlobe was divided into 20 areas. Each area was punctured with a fine needle and the pain was assessed by the visual analog scale (VAS). Then, localized cooling or warming was applied before puncture and the pain was assessed by the VAS.Results The VAS tended to be lower toward the lower part of the earlobe. The VAS in the uppermost area was 53.1±19.1 mm and 28.9±16.8 mm in the lowest part of the earlobe. The VAS was higher in the uppermost area than in the lowest area in six of the seven volunteers (p=0.028). We did not find significant differences in the VAS and blood glucose levels between the control sampling and the warming, or cooling sampling. The localized warming shortens the time to obtain blood by 4.4 seconds (p= 0.0426).Conclusion The area of the ear, but not localized cooling or warming, significantly affects the pain in sampling blood from the earlobe. Blood sampling for glucose tests are recommended to be obtained at the lower pole of the earlobe.

Equivalence of Earlobe Site Blood Glucose Testing With Finger Stick

“…There is a considerable body of evidence suggesting that the earlobe is a less painful site than the finger for glucose testing (Carley et al, 2000;Shibata, Nurashige, & Kami, 2004;Toledo & Taylor, 2004) but little evidence to show a correlation of glucose concentrations, especially in a heterogeneous population. There is no evidence to show a correlation in hypoglycemic state.…”

The accuracy and acceptability of performing capillary blood glucose measurements at the earlobe

“…Shibata et al . () noted that the earlobe is also innervated with nociceptors and they concluded that pricking the lower part of the earlobe resulted in the least pain. Following this, the study nurse also asked the participant to rate the level of pain for the procedure on the Faces Pain Scale.…”

“…Then, the study nurse obtained a blood sample for capillary blood glucose monitoring at the lower part of the earlobe, which was taken at the same side as the fingertip used for blood glucose monitoring. Shibata et al (2004) noted that the earlobe is also innervated with nociceptors and they concluded that pricking the lower part of the earlobe resulted in the least pain. Following this, the study nurse also asked the participant to rate the level of pain for the procedure on the Faces Pain Scale.…”

“…The major concern about the use of alternative sampling sites is reliability because inaccuracy of the blood glucose measurements will affect the treatment and, thus, could be dangerous for clients. Empirical studies have been conducted to compare the blood glucose concentration levels at alternative body sites, such as the palm, forearm, thigh, calf and earlobe (Jungheim & Koschinsky 2002a, Bina et al 2003, Fedele et al 2003, Tieszen & New 2003, Dufaitrepatouraux et al 2004, Ferraz et al 2004, Shibata et al 2004, Toledo & Taylor 2004, Kempe et al 2005, Anzalone 2008, Knapp et al 2009, Ito et al 2010. Several studies have reported that blood glucose measurements taken at the forearm and thigh were less reliable in the presence of hypoglycaemia or hyperglycaemia, after a meal and after exercise because the blood glucose concentration at these sites lagged behind that at the fingertip by 30-60 minutes (Ellison et al 2002, Bina et al 2003, Fedele et al 2003.…”

“…Shibata et al . () only examined the level of pain caused by pricking the earlobe for blood glucose monitoring with an assumption that the earlobe is an appropriate alternative sampling site. Hence, although some studies have been performed to examine the reliability of blood glucose monitoring at the earlobe and although, from our understanding, such a practice has been adopted in some regions, evidence on its reliability is limited and inconclusive.…”