Why should blood not be drawn from strictly sclerosed veins?

Blood should not be drawn from strictly sclerosed veins primarily because they may have impaired circulation. Sclerosis refers to the hardening or thickening of the veins, which can occur due to various factors such as multiple punctures, phlebitis, or certain medical conditions. When veins are sclerosed, their structural integrity is compromised, leading to decreased blood flow. This impaired circulation can make it difficult to obtain a blood sample and may also pose risks to the patient, including the potential for inadequate or unusable specimens.

While painful experiences for the patient, risk of severe bleeding, and the tendency for the vein to collapse during puncture are considerations in vein selection, the central concern with sclerosed veins is their failure to provide adequate circulation, making them unsuitable for a blood draw.