///2017 Abstract Details
2017 Abstract Details2019-08-02T15:54:53-06:00

Anesthetic Management of Parturient with Spinal Muscular Atrophy

Abstract Number: SAT-83
Abstract Type: Case Report/Case Series

Alaeldin A Darwich MD1 ; Sharon Abramovitz MD2

Introduction: Spinal muscular atrophy (SMA) is a rare genetic neuromuscular disorder characterized by degeneration of the neuronal cells of the anterior horn of the spinal cord. There are four types of SMA based on the age of onset. Earlier onset of the disease correlates with the severity and the progression of muscle wasting and motor impairment. The majority of patients with SMA are wheelchair-bound secondary to weakness and atrophy of the proximal muscles of the lower extremities. Pulmonary complications are common due to respiratory muscle involvement. Many patients undergo early spinal instrumentation to correct progressive scoliosis due to weak paraspinal muscles.

Case: This 30 year-old nulliparous female with a history of SMA type III, SLE and anemia received a pre-anesthesia consultation regarding options for labor analgesia and anesthesia for CS secondary to extensive back surgery. She was later admitted to the hospital at 37 weeks gestation for dyspnea and preterm labor. Due to a failure of induction of labor, she was taken to the OR for Cesarean section (CS). She had a history of severe scoliosis and spinal fusion from T2 to the sacrum at the age of 12, complicated by prolonged tracheal intubation for 2 weeks due to severe atelectasis. General anesthesia (GA) was planned using awake fiber-optic (FOB) tracheal intubation, facilitated by remifentanil intravenous infusion, midazolam and topicalization of the airway with lidocaine. After successful tracheal intubation, GA was induced with propofol; neuromuscular blocking agents were not used. A healthy neonate was born with APGAR scores of 9/9. The patient was extubated at the end of the procedure in the OR and the post-operative course was uneventful.

Discussion: Regional anesthesia (RA) has been successfully reported in patients with SMA. However, these patients usually present with extensive spinal surgery, making RA technically challenging with a higher chance of failed or inadequate block. Also, the patient presented with dyspnea and RA with high thoracic block can lead to respiratory decompensation. Succinylcholine is contraindicated in SMA because of the risk of life threatening hyperkalemia. In addition, there is increased sensitivity to non-depolarizing muscle relaxants (NDMR), which may require prolonged ventilation, so these are best avoided.

Awake FOB intubation was used to manage the airway, to avoid NDMR and remifentanil is useful due to its rapid metabolism in both mother and fetal circulation. This case highlights the importance of early anesthetic consultation in high-risk parturients and the utilization of FOB skills when regional techniques and muscle relaxants are contraindicated.

As less GA is utilized for CS, FOB intubation should be performed regularly in non-obstetric settings or through the use of simulation to maintain skills.

References:

Giuseppe et al. JCA 2012;573-7

Habib et al. Int J Obstet Anesth 2005;366-7

Popat et al. Int J Obstet Anesth 2000;78-82

SOAP 2017