Use of the platelet function analyser PFA-100™ in juvenile pigs

To evaluate the platelet function analyser PFA 100™ and impact of sample storage for pigs, samples from 24 German large white swine (3–5 months) were measured 15 and 30 min (n = 24) and 1, 2, 4, 8 and 24 h (n = 9) after sampling. For the PFA-100™ analyses, 10–20 ml sodium citrate anticoagulated blood were withdrawn from the vena femoralis using a 5-F catheter. K2EDTA anticoagulated blood (1.2 ml) was taken for haematological analysis. Using collagen/ADP cartridges, 10 of 93 (10.8%) analyses were invalid (9.7% aborted measurement, 1.1% organizational problems). With collagen/epinephrine cartridges, 28 of 93 (30.1%) measurements were invalid (22.6% aborted measurement, 6.45% closure time above the measurement range, 1.1% organizational problems). The median closure time at time point 15 min was 72.0 s (range, 50–122 s) for collagen/ADP and 123.5 s (range, 90–204 s) for collagen/epinephrine. Invalid measurements were more frequent (P < 0.0001) with collagen/epinephrine cartridges. For both cartridges, no significant impact of storage time was seen (P = 0.202 and 0.260). Mean haematocrit value was 0.27 l/l (±0.04) and mean platelet count 343.5 × 109/l (±81.94). Therefore, collagen/epinephrine cartridges cannot be recommended to be used in pigs. In young animals with haematocrit values <0.25 l/l, prolonged closure times have to be considered, whereby the use of the PFA-100™ has to be seen critically. The wide reference range may limit its use to experimental settings rather than single individual measurements.