A primigravida at 41 weeks gestation is admitted to the labo… | 마이메르시 MyMerci
Maternal Newborn Health
문제

A primigravida at 41 weeks gestation is admitted to the labor unit with strong, regular contractions every 2-3 minutes lasting 60-90 seconds. Her cervix is 8 cm dilated, 100% effaced, and the fetal head is at 0 station. The fetal heart rate shows a baseline of 110-120 bpm with moderate variability, but late decelerations are noted with each contraction. Which nursing action should be the immediate priority?

해설
Late decelerations indicate uteroplacental insufficiency and fetal hypoxia. The immediate priority is to improve fetal oxygenation by positioning the client on her left side and administering oxygen. Other options are inappropriate as they delay intervention or worsen the condition.

심화 해설

Core Nursing Explanation Key Concept Analysis: This question tests the priority nursing intervention for Late decelerations during the active phase of labor. Late decelerations are a concerning pattern on the fetal heart rate (FHR) monitor, characterized by a gradual decrease in FHR that begins after the peak of a contraction and returns to baseline after the contraction ends. The pathophysiology is Uteroplacental insufficiency (UPI). During a contraction, blood flow through the uterine arteries to the placenta is temporarily reduced. In a healthy fetus, this is tolerated. However, in UPI, the placenta cannot deliver enough oxygen to the fetus during this stress, leading to fetal hypoxia, which triggers a reflex slowing of the heart rate. The scenario describes a patient at 41 weeks (post-term), which increases the risk of placental insufficiency. Answer Rationale: Key Point! The immediate priority for late decelerations is non-invasive intrauterine resuscitation to improve uteroplacental blood flow and fetal oxygenation. This is a two-step, simultaneous intervention: 1) Position on left side to displace the uterus off the maternal aorta and inferior vena cava, improving venous return and cardiac output, thereby maximizing blood flow to the placenta. 2) Administer oxygen at 8-10 L/min via non-rebreather mask to increase the oxygen saturation in maternal blood, which increases the oxygen available for diffusion across the placenta to the fetus. The FHR in this scenario still shows moderate variability, which is a reassuring sign of adequate fetal central nervous system oxygenation and reserve. This indicates there is time for these corrective measures before escalating to immediate delivery. Distractor Analysis: Watch out for confusion! Option ② (Prepare for immediate cesarean) is incorrect because, while late decelerations are serious, the presence of moderate variability suggests the fetus is not in immediate, catastrophic distress. The nurse's first action is always to attempt intrauterine resuscitation. Immediate preparation for surgery would be the priority if there were absent variability, prolonged decelerations, or bradycardia. Option ③ (Increase IV fluids and encourage pushing) is dangerous. The patient is only 8 cm dilated, which is still the Active phase, not the second stage. Encouraging pushing against a cervix that is not fully dilated is ineffective and can cause cervical edema or trauma. While increasing IV fluids (often a bolus of Lactated Ringer's) is part of intrauterine resuscitation, it is not the *immediate* standalone action, and pushing is contraindicated. Option ④ (Document and continue monitoring) represents a critical failure to act. Late decelerations are an abnormal finding requiring immediate intervention, not passive observation. Delaying intervention for 15 minutes could lead to worsening fetal acidosis. Related Concepts: The nurse must assess the entire FHR tracing, not just the decelerations. Key components are Baseline rate (110-120 bpm is normal), Variability (moderate is reassuring), and the type of deceleration. The management differs for Early decelerations (head compression, benign) and Variable decelerations (cord compression, often managed with position change and amnioinfusion).
Concept Summary
ConceptDescriptionNursing Implication
Late DecelerationGradual FHR decrease starting after contraction peak, mirroring contraction shape. Caused by Uteroplacental Insufficiency (UPI).PRIORITY: Left lateral position, O2, stop Pitocin (if running), IV fluid bolus.
Moderate VariabilityAmplitude range of 6-25 bpm. The single most reassuring sign of fetal well-being and adequate CNS oxygenation.Indicates time for corrective measures before emergency delivery is needed.
Intrauterine ResuscitationFirst-line interventions for non-reassuring FHR patterns: Position change, O2, IV fluids, discontinue oxytocin, consider tocolytics.Performed simultaneously and re-evaluated within a few minutes. If no improvement, prepare for expedited/operative delivery.
0 StationThe fetal presenting part (head) is at the level of the maternal ischial spines. This is engagement.Indicates descent into the pelvis. Pushing is only indicated at 10 cm dilation (2nd stage).

Side-by-Side Comparison!
Deceleration TypeShape & TimingPathophysiological CausePriority Nursing Action
LateGradual, onset after peak, nadir after peak, returns after contraction ends.Uteroplacental Insufficiency (Maternal hypotension, hypertension, placental abruption, post-term pregnancy).Left lateral position, O2, stop Pitocin, IV bolus.
EarlyGradual, mirror image of contraction (onset & nadir with contraction).Head Compression (Vagal response). Benign, normal in active labor.No intervention needed. Reassure patient.
VariableAbrupt, variable shape & timing, often "V" or "U" shaped.Umbilical Cord Compression (Oligohydramnios, nuchal cord).Change maternal position (Trendelenburg, knee-chest), O2, consider amnioinfusion.

Anatomy, Physiology & Pharmacology Points
  • Physiology: Left lateral positioning works by moving the gravid uterus off the Inferior vena cava (IVC), preventing supine hypotensive syndrome (aortocaval compression). This improves maternal venous return, cardiac output, and thus uterine artery perfusion.
  • Pharmacology: If oxytocin (Pitocin) is being administered for labor augmentation, the nurse must discontinue it immediately as part of intrauterine resuscitation, as oxytocin causes uterine contractions that exacerbate UPI.
  • Pathophysiology: Post-term gestation (>40 weeks) is a risk factor for UPI due to placental aging and calcification, reducing its efficiency in gas and nutrient exchange.

Memory Tips
  • LATE for PLACENTA: Late decelerations = Placental problem. Think "L" for "Lay her on her Left side and give Oxygen."
  • VEAL CHOP Mnemonic for FHR patterns: Variable decelerations = Cord Compression. Early decelerations = Head Compression. Accelerations = OK (Oxygenation is good). Late decelerations = Placental Insufficiency.

High-Frequency NCLEX Topics This is a classic NCLEX "priority-setting" and "delegation/action" question. The NCLEX loves to test: 1. Differentiating between types of FHR decelerations. 2. Knowing the first and most appropriate nursing action for each. 3. Understanding that moderate variability buys time for nursing interventions before moving to surgical delivery. 4. Recognizing contraindications (like pushing before complete dilation).
Watch Out for Question Variations!
  • If the scenario added "Absent variability" or "Prolonged deceleration to 80 bpm for 3 minutes", the correct answer would shift to "Prepare for immediate/emergent cesarean delivery."
  • The question could ask about the pathophysiological cause: "The nurse understands late decelerations are caused by which mechanism?" Answer: Uteroplacental insufficiency.
  • It could test the rationale for left lateral positioning: "To increase uteroplacental perfusion by relieving aortocaval compression."

임상 시나리오

Nursing Clinical Practice Guide Clinical Scenario: You are the nurse in a labor and delivery unit. Your patient, Anna, is 41 weeks pregnant with her first baby. She is in active labor, breathing through strong contractions. You are reviewing the electronic fetal monitor (EFM) strip and notice that with each contraction, the baby's heart rate dips down, and the lowest point occurs well after the peak of the contraction has passed. The rest of the tracing looks okay—the baseline is normal and there's a healthy amount of "wiggle" (variability). Anna is on an IV with Lactated Ringer's and is receiving continuous EFM. Nursing Intervention Strategy: 1. Immediate Action (Simultaneous): * Reposition: Gently assist Anna to turn onto her left side. Use pillows for support. If she cannot tolerate left side, try right side. The goal is to get her off her back. * Oxygen: Apply a non-rebreather face mask, ensure the reservoir bag is inflated, and set the flow rate to 8-10 liters per minute. Explain to Anna, "We're giving you some extra oxygen to help the baby, just like putting on an oxygen mask on an airplane. It's a precaution." 2. Secondary Actions (Rapid Sequence): * Discontinue Oxytocin: If Anna is receiving Pitocin via IV pump, stop the infusion immediately. * Increase IV Fluids: Open the main IV line to a rapid bolus (e.g., 500-1000 mL bolus of Lactated Ringer's as per protocol) to increase maternal intravascular volume and placental perfusion. * Notify: Inform the primary nurse, charge nurse, and provider (physician or midwife) of the findings and your actions. Your report should be concise: "Patient at 8 cm with late decels, moderate variability. We've positioned left lateral, started O2 at 10L, and stopped the Pitocin." 3. Reassessment: Closely monitor the EFM for the next 15-30 minutes. You are looking for resolution of the late decelerations and maintenance of moderate variability. If the pattern corrects, you continue supportive care. If it worsens (e.g., variability becomes minimal/absent), you escalate immediately. Patient Safety and Precautions: * Never encourage pushing before complete dilation (10 cm). This can cause cervical damage and is exhausting for the mother. * Ensure oxygen equipment is functioning correctly. A non-rebreather mask is used to deliver high FiO2 (fraction of inspired oxygen). * Monitor for maternal fluid overload during IV bolus, especially in patients with cardiac or renal history.
Nursing Procedure & Medication Flow Procedure: Responding to Late Decelerations 1. Assess the entire FHR tracing: Baseline, Variability, Presence of Accelerations, Decelerations (type). 2. Initiate Intrauterine Resuscitation: a. Position: Left lateral (or right lateral). b. Oxygen: Non-rebreather mask at 8-10 L/min. c. IV: Bolus of isotonic crystalloid (e.g., 500 mL LR over 15-20 min). d. Medication: Discontinue any uterotonic agents (Oxytocin/Pitocin). 3. Notify the healthcare provider. 4. Consider internal monitoring (Fetal Scalp Electrode, Intrauterine Pressure Catheter) for more accurate data if not already in place. 5. Reassess FHR tracing within 5-10 minutes. 6. If no improvement or pattern worsens, prepare for expedited delivery (assist with preparations for operative vaginal delivery or cesarean section).
A Word from Your Senior Nurse "In the controlled chaos of labor and delivery, the fetal heart monitor is your window into the baby's world. When you see late decelerations, don't panic—act. Your quick thinking with position change and oxygen is often all it takes to turn the situation around and give that baby the oxygen boost it needs. Remember, you are the one at the bedside watching the strips in real-time. Your ability to recognize abnormal patterns and initiate evidence-based interventions before the situation becomes critical is what defines expert nursing care. On the NCLEX, they are testing this exact clinical judgment: see a problem, know the first best step. In real life, that step saves lives."

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