Mixed Deck — All EFM Topics Flashcards

A patient has an intrauterine pressure catheter (IUPC) in place. Over a 10-minute period, there are four contractions. The peak pressures are 60, 65, 70, and 60 mm Hg, and the resting tone is 15 mm Hg. What are the calculated Montevideo Units (MVUs) for this period?

Answer: 200 MVUs

Montevideo Units (MVUs) are calculated by summing the intensity of each contraction in a 10-minute window. Intensity is defined as the peak pressure minus the resting tone. Calculation: (60-15) + (65-15) + (70-15) + (60-15) = 45 + 50 + 55 + 45 = 200 MVUs. A value of 200 MVUs or greater is generally considered adequate for active labor progress.

When documenting a category II fetal heart rate tracing, what is the MOST important element to record?

Answer: Interventions performed and fetal response

Documenting the interventions performed and the fetal response demonstrates clinical action taken and establishes a clear record for continuity of care.

During a uterine contraction, blood flow through the uterine spiral arteries temporarily decreases. What is the primary reason for this reduction in flow?

Answer: Increased intramyometrial pressure compressing the vessels

Uterine contractions increase the pressure within the myometrium (intramyometrial pressure). This increased pressure compresses the spiral arteries that perfuse the intervillous space of the placenta. When the intramyometrial pressure exceeds the pressure within the arteries, blood flow is significantly reduced or even temporarily stopped, leading to a transient decrease in oxygen transfer to the fetus.

A patient receiving oxytocin for labor augmentation develops uterine tachysystole (six contractions in 10 minutes) accompanied by recurrent late decelerations. What is the FIRST priority nursing intervention?

Answer: Discontinue the oxytocin infusion.

The first and most critical intervention for uterine tachysystole caused by oxytocin is to stop the causative agent. Discontinuing the oxytocin infusion is the fastest way to begin reducing uterine activity and improve blood flow to the fetus, which can resolve the associated late decelerations. Other resuscitative measures may follow, but stopping the oxytocin is the priority.

A normal umbilical artery bicarbonate (HCO3-) level at delivery is approximately:

Answer: 22 – 26 mEq/L

Normal umbilical artery bicarbonate is approximately 22–26 mEq/L, reflecting adequate bicarbonate buffering capacity in the fetus at delivery.

Which type of acidosis is characterized by an elevated PCO2 and normal base deficit in fetal cord blood?

Answer: Respiratory acidosis

Respiratory acidosis results from acute CO2 accumulation (elevated PCO2) without significant base deficit, often due to transient cord compression.

A nurse is concerned about a persistent Category II tracing with recurrent late decelerations. The attending physician was notified 30 minutes ago but has not come to the bedside or provided new orders. From a professional and legal standpoint, what is the nurse's most critical next action?

Answer: Initiate the established institutional chain of command.

The nurse has a professional and legal duty to advocate for patient safety. When the primary provider is unresponsive or there is a disagreement on the plan of care for a concerning clinical situation, the nurse must activate the hospital's chain of command to escalate the concern to the next level of authority (e.g., charge nurse, unit manager, chief of obstetrics). This ensures the situation is addressed promptly and fulfills the nurse's advocacy role. While the other actions are relevant, they do not resolve the critical issue of an unresponsive provider.

Which EFM pattern is classically associated with complete placental abruption?

Answer: Prolonged deceleration or sudden bradycardia with loss of variability

Complete placental abruption causes sudden cessation of uteroplacental blood flow, producing a prolonged deceleration or sustained bradycardia with loss of variability.

When documenting fetal heart rate accelerations, which detail is required to meet the standard NICHD definition in a term fetus?

Answer: Peak ≥15 bpm above baseline lasting ≥15 seconds

In a term fetus, an acceleration is defined by NICHD as a peak of at least 15 bpm above baseline with a duration of at least 15 seconds.

Which of the following describes the criteria of an acceleration after 32 weeks gestation?

Answer: A rise in the fetal heart rate of at least 15 bpm for at least 15 seconds

Explanation: Accelerations in fetal heart rate after 32 weeks gestation are defined by an increase in the fetal heart rate of at least 15 beats per minute (bpm) above the baseline, lasting for at least 15 seconds. This criteria indicates fetal well-being and is considered reassuring during electronic fetal monitoring.

Which of the following represents a critical element of legally defensible charting related to a non-reassuring (Category II or III) fetal heart rate tracing?

Answer: Documenting the specific actions taken in response to the tracing and the subsequent fetal response.

Legally sound documentation must be objective, timely, and complete. For a non-reassuring tracing, it is essential to document not only the interpretation of the FHR pattern but also the specific interventions performed (e.g., position change, IV fluid bolus), all notifications made to the provider, and the subsequent fetal response to those interventions. This creates a clear record of assessment, action, and re-evaluation, which is a cornerstone of legal defense.

A laboring patient with an EFM tracing showing recurrent late decelerations and minimal variability is placed in a left lateral position. What is the primary physiological goal of this intervention?

Answer: To increase maternal cardiac output and improve uteroplacental perfusion.

Placing the patient in a lateral position, particularly the left lateral, displaces the gravid uterus off the inferior vena cava and aorta. This action increases venous return to the heart, boosts maternal cardiac output, and consequently improves blood flow to the placenta, which helps to correct the uteroplacental insufficiency indicated by late decelerations.

A patient receiving terbutaline for uterine tachysystole develops a fetal heart rate baseline of 165-170 bpm. This change is most likely attributable to which of the following?

Answer: Sympathomimetic effect of the medication

Terbutaline is a sympathomimetic drug (a beta-adrenergic agonist) that can cause maternal and subsequent fetal tachycardia as a side effect. Maternal hypotension and increased vagal tone would more likely cause bradycardia or decelerations. A fetal sleep cycle is typically associated with minimal variability and a stable baseline within the normal range, not tachycardia.

Are there accelerations present?

Answer: Yes

Explanation: There are accelerations present in addition to the marked variability.

Which of the following is the most important characteristic of fetal heart tracings to determine fetal well-being?

Answer: Variability

Explanation: Variability is the single most important determinant of fetal well-being.

Which of the following interventions or conditions is LEAST likely to cause a decrease in or absence of fetal heart rate variability?

Answer: Fetal acoustic stimulation

Fetal acoustic stimulation is a method used to elicit an acceleration in the fetal heart rate, which demonstrates fetal well-being. It is intended to stimulate the fetus, often increasing activity and variability, not decrease it. In contrast, medications like magnesium sulfate and narcotics, as well as normal fetal sleep cycles, are all well-known causes of decreased or minimal FHR variability.

An elevated fetal PCO2 in cord blood gas analysis most directly indicates:

Answer: Impaired CO2 clearance across the placenta

Elevated PCO2 indicates that CO2 produced by fetal metabolism is not being adequately cleared by the placenta, typically due to acute uteroplacental insufficiency or cord compression.

What is the normal pH range for umbilical artery blood at delivery?

Answer: 7.25 – 7.35

A normal umbilical artery pH at delivery is 7.25–7.35, reflecting adequate fetal acid-base status.

What category is this tracing?

Answer: Category 2

Explanation: It is Category 2 tracing. Category 2 tracing in Electronic Fetal Monitoring (EFM) represents an indeterminate or non-reassuring fetal heart rate pattern.

Assuming the patient has an IUPC, please calculate the MVUs for this tracing.

Answer: 245

Explanation: The MVUs for this tracing would be 245.