A gravida 1, para 0 patient at 38 weeks of gestation presents to the obstetric triage unit… — USMLE Step 2 CK

A gravida $1$ , para $0$ patient at $38$ weeks of gestation presents to the obstetric triage unit with a chief complaint of a sudden gush of clear vaginal fluid that occurred $20$ hours ago. She is currently experiencing painful uterine contractions every $3$ to $4$ minutes. Her temperature is $39.1^\circ\text{C}$ ( $102.4^\circ\text{F}$ ), blood pressure is $112/74\text{ mm Hg}$ , pulse is $115/\text{min}$ , and respiratory rate is $18/\text{min}$ . Physical examination reveals a tender uterine fundus. The cervix is visually assessed at $5\text{ cm}$ dilation and $90\%$ effacement. The fetal heart rate monitor displays a baseline of $168/\text{min}$ with moderate variability and no decelerations. Which of the following is the most appropriate next step in the management of this patient?

A
Initiation of intravenous vancomycin and piperacillin-tazobactam
B
Placement of an intrauterine pressure catheter and amnioinfusion
C
Immediate operative abdominal delivery
Administration of intravenous ampicillin and gentamicinAnswer
E
Reassurance and administration of oral antipyretics

Answer

Administration of intravenous ampicillin and gentamicin

The correct answer addresses the acute intraamniotic infection with standard first-line intravenous antibiotics (ampicillin and gentamicin). The diagnosis is confirmed by maternal fever, uterine tenderness, and prolonged rupture of membranes. The fetal tachycardia is a secondary response to the maternal fever, and because the tracing remains reassuring (moderate variability), labor can safely continue after antibiotics are initiated.

Step-by-Step Solution

Analyze the maternal vital signs and physical examination findings.

The patient has a significant fever, tachycardia, prolonged rupture of membranes (>18 hours), and uterine fundal tenderness.

These are the classic clinical diagnostic criteria for intraamniotic infection (chorioamnionitis).

Evaluate the fetal heart rate tracing.

The baseline is elevated at 168/min (fetal tachycardia), but there is moderate variability and no decelerations.

Fetal tachycardia is an expected secondary finding in the setting of maternal fever/infection. The presence of moderate variability indicates that the fetus is not currently acidemic, ruling out the immediate need for emergent delivery.

Determine the standard management for the diagnosed condition.

Administer broad-spectrum intravenous antibiotics to cover ascending polymicrobial flora (ampicillin and gentamicin) and allow labor to progress.

Prompt antibiotic administration prevents maternal sepsis and reduces neonatal morbidity, while vaginal delivery remains the safest and preferred route unless specific obstetric contraindications arise.

Key Concept

Management of Intraamniotic Infection (Chorioamnionitis)

Question

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Topics

More questions from this topic