A 32-year-old woman, gravida 1 para 1, is evaluated on postoperative day 1 for difficulty walking. Yesterday, the patient underwent a prolonged induction of labor for poorly controlled gestational diabetes mellitus and suspected fetal macrosomia at 39 weeks gestation. Epidural analgesia was placed during labor, and she required multiple epidural boluses and epidural replacement for adequate pain control. The patient pushed for 3 hours with minimal fetal descent, and a forceps-assisted delivery was attempted but failed. She then underwent a cesarean delivery via Pfannenstiel incision. Today, while attempting to walk to the bathroom, the patient almost fell and has been unable to ambulate without assistance. On examination, the Pfannenstiel incision is intact and mildly tender. The right patellar reflex is 2+ and the left 1+. Sensation is diminished on the left anterior and medial thigh, and there is weakness on knee extension. The remainder of the examination is normal. Which of the following is the most likely cause of this patient's presentation?

Question

A 32-year-old woman, gravida 1 para 1, is evaluated on postoperative day 1 for difficulty walking.  Yesterday, the patient underwent a prolonged induction of labor for poorly controlled gestational diabetes mellitus and suspected fetal macrosomia at 39 weeks gestation.  Epidural analgesia was placed during labor, and she required multiple epidural boluses and epidural replacement for adequate pain control.  The patient pushed for 3 hours with minimal fetal descent, and a forceps-assisted delivery was attempted but failed.  She then underwent a cesarean delivery via Pfannenstiel incision.  Today, while attempting to walk to the bathroom, the patient almost fell and has been unable to ambulate without assistance.  On examination, the Pfannenstiel incision is intact and mildly tender.  The right patellar reflex is 2+ and the left 1+.  Sensation is diminished on the left anterior and medial thigh, and there is weakness on knee extension.  The remainder of the examination is normal.  Which of the following is the most likely cause of this patient's presentation?

Quizplus · Accepted Answer

11ec25c8_da60_16ed_bc81_650d3450d365_MD0003_00 This patient's impaired ambulation, decreased sensation on her anteromedial thigh, and absent patellar reflex are consistent with a femoral nerve neuropathy. The femoral nerve arises from L2-L4 and travels under the inguinal ligament to provide sensation to the anteromedial thigh and motor innervation for muscles of hip flexion (eg, iliacus, sartorius) and leg extension (eg, quadriceps femoris). During the second stage of labor, the pushing of the legs up and back, along with flexion of the hips, helps facilitate delivery while the patient pushes. The degree of hip flexion can go unrecognized in patients who have epidural analgesia because sensory feedback is limited, resulting in hip hyperflexion. In these patients, the femoral nerve can become entrapped and compressed under the inguinal ligament, which can lead to a pressure-induced nerve ischemia, resulting in the characteristic impaired leg extension (eg, difficulty walking) and decreased anteromedial thigh sensation. Management is conservative with supportive care (eg, physical therapy) because most patients recover within several weeks. (Choice B) A spinal epidural hematoma is a potential complication of neuraxial anesthesia. Bleeding within the spinal canal causes cord compression and typically leads to progressive motor and sensory deficits in the distribution of the affected nerve root (L4-L5 with labor analgesia). Due to the insertion of the needle in the lower lumbar spine, cauda equina syndrome with bowel and bladder dysfunction may occur. (Choice C) The iliohypogastric nerve can be injured during a cesarean delivery via Pfannenstiel skin incision; patients with injury typically have decreased sensation or burning pain at the suprapubic region. iliohypogastric nerve (Choice D) The pudendal nerve can be injured during a prolonged second stage of labor or forceps-assisted delivery because of its curved course around the ischial spine. Patients with this injury typically have increased vulvar pain and possible decreased anal sphincter tone (eg, fecal incontinence). pudendal nerve Educational objective: Hyperflexion of the hips during the second stage of labor can compress and entrap the femoral nerve under the inguinal ligament and cause a pressure-induced ischemia, leading to decreased anteromedial thigh sensation and weakness with hip flexion and leg extension.

A 32-Year-Old Woman, Gravida 1 Para 1, Is Evaluated on Postoperative