[Appearance of hematomas after blood extractions related with needle gauge related]

We want to know the method that less damage produced in the patient when making a venous blood extraction. The objective of this study is to compare the system of extraction that provokes less hematomas and reduces pain in the patients. We studied 175 patients; the variables studied were age, duration of the technique, occurrence of haematoma, pain perceived according to numerical scale of the pain. The study shows that does not exist relation between the appearance of haematomas and the catheter with which the venous puncture is realized, at least, not between catheters of 21 and 20 gauge. It was noted that the patients feel less pain when needles of calibre 21 gauge (butterflies) were used. The extraction time is lightly bigger with this system, but if we want to offer some quality care, we must perform the extraction of blood with the butterfly device (needles of 21 G).