American Society for Clinical Pathology (ASCP) Histotechnician Certification Practice Exam

What is the preferred depth of incision for a skin puncture on a premature infant?

1. 0.5 mm

2. 0.75 mm

3. 0.85 mm

4. 1.0 mm

The correct answer is: 0.85 mm

For performing a skin puncture on a premature infant, the preferred depth of incision is 0.85 mm. This depth is optimal because it allows for sufficient penetration to collect the necessary blood sample while minimizing the risk of damage to underlying tissues. Premature infants have delicate and thin skin, making it crucial to avoid deeper punctures that could lead to complications such as excessive bleeding or injury to nerves and blood vessels. Choosing a depth greater than 0.85 mm may increase the likelihood of these complications, while a lesser depth may not provide enough blood for testing, compromising the effectiveness of the procedure. Therefore, 0.85 mm balances the need for a proper sample with the requirement of safety and care inherent in handling vulnerable populations like premature infants.