NCLEX Exam Practice Question of the Week - 04/13/11

Elsevier NCLEX Exam Review

Question: A lecithin-sphingomyelin (L/S) ratio is ordered for a primigravida client at 35 weeks' gestation. What is the goal of this test?

1. To determine fetal lung maturity.
2. To evaluate the level of maternal-fetal estriol production
3. To check the position of the fetal head
4. To test the intrauterine fetal-placental circulation


Answer: 1

Rationale: An L/S ration (converts 2:1 at approximately 34 to 35 weeks' gestation) determines the relationship of two components of the fetal lung (lecithin and sphingomyelin) known as surfactant. Adequate surfactant must be present at birth for the alveoli to maintain expansion.

This week’s NCLEX exam practice question can be found in:
Zerwekh: Illustrated Study Guide for the NCLEX-RN Exam, 7th edition, Chapter 24 Page 523 Question 11

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