Vascular Access Exam Prep

Answer: B - The needle identified as an 18-gauge needle has a larger bore than a 22-gauge needle. The numbers indicate the width of the bore of the needle. The SMALLER the number, the LARGER the bore of the needle. Generally, a 20-gauge needle is used in venipuncture. During the assessment, the nurse determines what size gauge is most appropriate for performing a successful blood collection on that specific patient. This determination is based on size of the patient’s vein, findings gathered from palpitation. It is part of the nurse responsibility to understand the effects of different gauge needles on blood and blood products.