Invasive procedures cause undesirable pain and stress in sick newborn infants. Mini-erosion dermal access (MEDA) is well documented with regard to systemic drug delivery (morphine, DDAVP) and glucose measurements in adults. This method has now been adapted for newborn infants.

Method: MEDA was obtained using a standardized suction technique(Sampling devices, Epiport, Sweden) in 24 newborn infants (28-42 gestational weeks) and evaluated by means of electron microscopy (EM), laser Doppler perfusion imaging (LDI) and evaporimetry. ISF was extracted serially during 1-3 days. Glucose levels in ISF were measured photometrically (adapted Hemocue, HC) vs. enzymatically (YSI) in umbilical arterial blood.

Results: The technique was applicable in all infants with no signs of pain or stress. The epidermal barrier with adjoining 2-3 layers of epidermal cells were split off reproducibly (EM). The LDI values (day 4) were 1.7±0.4 V (mean SD, access site) vs. 1.3±0.3 V (control, p<0.01), confirming the presence of the late phase of the dermal protective/regenerative response that has been described in adults (immediate and protracted dermal hyperemia, normal oxygenation). ISF was extracted serially at rates of 2-4 μL per minute, 12 times during 3 days, after which the skin barrier regenerated in 2-4 days (evaporation rates normalized). The site appeared normal at 7 days with no signs of complications. The ISF-HC glucose value was 3.5±1.0 mmol/L (mean±SD, range 1.9-6.6) vs. 3.7±1.0 mmol/L (range 2.0-5.4) for YSI (44 pairs).

Conclusion: MEDA is a feasible method for serial sampling of ISF and may become an alternative to conventional invasive blood sampling procedures in newborn infants. A modified sampling device (Epiport) is entering a testing stage.