Labor Epidural in a Patient with Noonan Syndrome
Abstract Number: 25
Abstract Type: Case Report/Case Series
Noonan syndrome is an uncommon congenital condition affecting both sexes, with a prevalence between 1:1000 and 1:2500 (1). It may include skeletal deformities, cardiac defects, craniofacial anomalies, and mental retardation, which may further alter the expected anatomic and physiologic changes of pregnancy (2,3). Scant information exists regarding Noonan syndrome and labor analgesia with only four articles available in the English literature since 1988 (2-5).
A 20-year-old primigravida presented at 39 4/7 weeks for induction of labor. History included pulmonary valve stenosis, with balloon valvuloplasties done in 1994 and 2000. She had a Mallampati class 2 airway, with short neck, small jaw and webbed neck. Other diagnoses included developmental delay and anxiety disorder. She was 154 cm tall, weighed 67.2 kg, and had obvious scoliosis. Laboratory values were normal.
When analgesia was requested, a lumbar epidural catheter was placed in the seated position via an 18 gauge Hustead needle. The procedure was technically difficult due to short stature, scoliosis, and patient movement.
Blockade reached T6 bilaterally with an infusion of 0.125% bupivacaine with 2 mcg/mL fentanyl at 10 mL per hour and patient-controlled epidural boluses. The baby was delivered using vacuum assistance.
A parturient with Noonan syndrome presents several anesthetic challenges. Decreased intervertebral distance, short stature, scoliosis, and exaggerated lumbar lordosis may hinder access to epidural space (6,7). A thorough evaluation of airway is mandatory as craniofacial abnormalities, such as arched palate and micrognathia, in conjunction with edematous mucosa typically found in pregnancy may make tracheal intubation difficult (5,8). Congenital cardiac defects, most commonly pulmonary stenosis and cardiomegaly, may limit cardiopulmonary reserve (9). In a patient with pulmonary stenosis it is desirable to minimize cardioacceleration and maintain appropriate systemic vascular resistance.
A parturient with Noonan syndrome may present a challenge to both the anesthesia and obstetric teams. Ideally, the patient would be evaluated and consented for epidural before she progresses to a point in her labor where her pain was unbearable. Doing so may allow a more technically facile placement and avoid tachycardia and hypotension. Fortunately, our patient had a favorable outcome despite her medical problems and difficulty cooperating.
1. Am J Hum Genet 2002; 70: 1555-63.
2. Middle East J Anes 2000; 15:611-7.
3. Can J Anes 2006; 53:274-8.
4. Anesthesiology 1988; 68:636-8.
5. Br J Anaes 1996; 77: 665-8.
6. J Bone Joint Surg 2001; 83: 1495-502.
7. Anesthesiology 1980; 52: 264-6.
8. Can J Anaes 1998; 45:332-6.
9. Anaesthesia 1992; 47: 131-3.