Use of blood from arterialised capillaries in the ears of calves for the analysis of pO2, pCO2, pH and bicarbonate.

Ears of calves were made hyperaemic by using a rubefacient. Blood from the hyperaemic ear was sampled in capillary tubes and analysed for pO2, pCO2, pH and bicarbonate. The results were compared with those obtained for blood taken from the brachial artery of the same animals. For pO2 and bicarbonate values a highly significant correlation was found between the two sets of results (P less than 0.001); for pH and pCO2 close correlations were found (P less than 0.01). The results indicate that blood samples from arterialised capillaries can be used as a substitute for blood obtained by arterial puncture.