Question 53

Perpendicular to the fingerprint grooves

For a capillary blood collection on a healthy adult patient, the lancet should be positioned perpendicular to the fingerprint grooves. This positioning allows for optimal blood flow and minimizes the risk of tissue damage.

A) Perpendicular to the fingerprint grooves

This option is correct because positioning the lancet perpendicular to the fingerprint grooves ensures that the puncture is made in a way that maximizes blood flow while reducing the chances of hitting deeper tissues. This technique also aligns with recommended practices for effective capillary blood sampling.

B) Parallel to the nail bed

This option is incorrect because positioning the lancet parallel to the nail bed does not facilitate effective blood collection. It can also lead to a suboptimal puncture that may not yield sufficient blood or could cause discomfort to the patient.

C) Along the lateral portion of the first digit

This option is not appropriate for capillary blood collection. While the lateral portion of the first digit may be a puncture site, it is not the recommended position as it does not leverage the optimal angle for blood flow, which is crucial for obtaining a sufficient sample.

D) Along the medial portion of the fifth digit

This option is also incorrect as the medial portion of the fifth digit is not ideal for capillary blood collection. Similar to option C, this position may not provide the best access to capillary blood, leading to inadequate sampling.

Conclusion

The correct answer, which is to use the lancet perpendicular to the fingerprint grooves, is essential for effective capillary blood collection. This technique ensures sufficient blood flow and minimizes the risk of tissue damage, while the other options fail to provide the necessary conditions for a successful collection. Proper positioning is critical in phlebotomy to ensure patient safety and sample integrity.