A pregnant client at 34 weeks gestation undergoes a non-stress test (NST). The fetal heart rate tracing shows a baseline of 140 bpm with moderate variability and three accelerations of 15 bpm lasting for 15 seconds within a 20-minute period. How should the nurse interpret these findings?

1. A

   Reactive NST, indicating fetal well-being

2. B

   Non-reactive NST, requiring further evaluation

3. C

   Positive NST, suggesting fetal compromise

4. D

   Sinusoidal pattern, indicating severe fetal anemia

Appeared in: NORCET 9 Prelims-2025

Explanation

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• A reactive Non-Stress Test (NST) is defined by the presence of two or more fetal heart rate (FHR) accelerations that are at least 15 beats per minute (bpm) above the baseline and last for at least 15 seconds, all occurring within a 20-minute window.
• The client's tracing shows three such accelerations, along with a normal baseline FHR of 140 bpm and moderate variability, which fully meets the criteria for a reactive result.
• A reactive NST is a reassuring sign, indicating that the fetal central nervous system is intact and the fetus is well-oxygenated, with a low probability of fetal death within the next week.

Why Other Options Were Wrong

• Option B: A non-reactive NST is characterized by the absence of sufficient FHR accelerations (fewer than two qualifying accelerations in a 40-minute period). The tracing in the question clearly shows three accelerations, making this interpretation incorrect.
• Option C: The term 'Positive' is not used in the interpretation of a Non-Stress Test. It is terminology used for a Contraction Stress Test (CST), where a 'positive' result is abnormal and indicates late decelerations with contractions.
• Option D: A sinusoidal pattern is a specific, ominous FHR pattern characterized by a smooth, regular, sine wave-like appearance with absent variability and no accelerations. The tracing described has moderate variability and accelerations, which is inconsistent with a sinusoidal pattern.

Related Visual

• Visual 1: FHR Tracing - A sample fetal heart rate tracing clearly showing a reactive pattern. The baseline, moderate variability, and at least two 15x15 accelerations should be labeled to help learners identify the key components.
• Visual 2: FHR Tracing - A comparative tracing showing a non-reactive pattern, highlighting the lack of sufficient accelerations over a 40-minute period.
• Visual 3: FHR Tracing - An example of an ominous sinusoidal FHR pattern to contrast with the reactive and non-reactive tracings.

Clinical Relevance

• Nursing practice connection: Use the key finding related to Interpretation of Non-Stress Test (NST) Results to guide bedside assessment, documentation, and the next nursing action.
• Nurses are frequently responsible for performing NSTs, interpreting the results, and communicating them to the healthcare provider. A correct interpretation is vital for ensuring fetal safety and guiding further management.
• A reactive NST is reassuring and generally indicates that no immediate intervention is necessary. The plan would typically be to continue routine antepartum surveillance as indicated for the pregnancy.
• What if? - If the NST had been non-reactive after the initial 20 minutes, the nurse's first action would be to extend the test for another 20 minutes to account for a possible fetal sleep cycle. If it remained non-reactive, vibroacoustic stimulation might be used to attempt to elicit accelerations before notifying the provider for further evaluation, such as a biophysical profile (BPP).

How to Approach the Question

• First, identify the core task: interpreting the results of a Non-Stress Test (NST).
• Recall the specific criteria for a 'reactive' NST in a fetus at or beyond 32 weeks' gestation. This is the '15x15 rule': at least two accelerations, rising at least 15 bpm above baseline, and lasting for at least 15 seconds, all within a 20-minute period.
• Systematically compare the data provided in the question (34 weeks, baseline 140 bpm, moderate variability, three accelerations of 15 bpm for 15 seconds in 20 minutes) with the standard criteria.
• Observe that the findings in the scenario (three accelerations) exceed the minimum requirement (two accelerations) for a reactive test.
• Evaluate the other options. Recognize that 'non-reactive' is the opposite finding, 'positive' is incorrect terminology for an NST, and 'sinusoidal' describes a very different, specific, and ominous pattern.
• Conclude that the findings meet the definition of a reactive NST, which signifies fetal well-being.

Concept Tested & Keywords

• Concept Tested: Interpretation of Non-Stress Test (NST) Results
• Stem keywords: non-stress test, NST, fetal heart rate, 34 weeks gestation, accelerations, moderate variability
• Lead-in keywords: interpret these findings
• Clinical cues: 34 weeks gestation is significant as the criteria for a reactive NST change at 32 weeks (from 10x10 to 15x15 accelerations).

Question ID

QIn_L0jQ_s4KfSR984SJrA

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