///2014 Abstract Details
2014 Abstract Details2019-07-18T14:34:47-06:00

Is MRI Warranted for the Pregnant Achondroplastic Patient? ACHONtroversial Topic

Abstract Number: F-38
Abstract Type: Case Report/Case Series

Antonio Gonzalez MD1 ; Mark Escudero MD2; Sherelle Laifer-Narin MD3; Richard Smiley MD, PhD4

Introduction: Achondroplasia is the most common form of non-lethal skeletal dysplasia, short-limb dwarfism1. The anatomic features of these patients can pose difficulties for administration of general or neuraxial anesthesia. We present the management of an achondroplastic patient where an MRI helped tailor our anesthetic plan and may explain some of our intraoperative observations.

Case: A 35 year old nulliparous achondroplastic patient, 4 feet tall (121.9 cm) and 52.2 Kg was referred to our anesthesia consult service. She denied any medical problems. Physical examination revealed a Mallampati 2 airway, suitable mouth opening, and full range of neck motion. Spinous processes were palpable in the midline. Surgical history included laparoscopic surgery during which an awake fiberoptic intubation had been electively performed. The patient strongly desired to be awake during the cesarean delivery. MRI ordered prior to the consultation revealed “diffuse congenital spinal stenosis-severe (L1-L3) to mild (L5-S1)-consistent with achondroplasia;” of note, there was a “loss of subarachnoid space at the L1-L2 level”(Figure1). The patient presented at our institution in preterm labor at 36 weeks 5 days gestation. A CSE anesthetic was performed at what was presumed to be the L4-L5 interspace; 2.5 mg bupivacaine and 5 mcg fentanyl were injected intrathecally. This had no effect on her labor pain over 10 min. A surgical T4 level of anesthesia was obtained with a total of 15ml of 2% lidocaine/epinephrine/HCO3, titrated 3ml at a time at 4-5 min intervals.

Discussion: The endochondral premature ossification in achondroplastic patients translates into a narrow spinal canal with areas of spinal stenosis2. The MRI allowed us to identify these areas of spinal stenosis, identify areas of relatively normal spinal anatomy, and to predict that spinal anesthetic spread could be compromised at L1 level. This was confirmed when our spinal “labor analgesia dose” only achieved a T12/L1 level after 10 minutes of administration and failed to relieve labor pain. Unusual spread of spinal local anesthetics has been reported before in achondroplastic patients, and may be related to spinal stenosis or other abnormalities. Neuroimaging technology might be useful to “personalize” neuraxial anesthetic techniques for these patients.

1. Baujat G. Best Pract Res Clin Rheumatol 2008;22:3–18

2. Jeong ST. J Bone Joint Surg 2006;88-B:1192–6.

3. DeRenzo JS. Int J Obstet Anesth 2005;14:175–8.

SOAP 2014