GA5-97
Intrathecal Spinraza: Anesthetic Implications for Expensive but Life-Altering Injections
1Latin I, 2Goldfinger M, 3Adamic S, 3Westover J
1University Hospitals Rainbow Babies & Children's, Cleveland, OH, USA; 2University Hospitals Rainbow Babies & Children's Hospital, Cleveland, OH, USA; 3University Hospitals Rainbow Babies and Children's Hospital, Cleveland, Ohio, USA
Spinal Muscular Atrophy (SMA) is a progressive motor neuron disorder and the most common genetic cause of infant mortality. SMA is caused by the loss of function of the Survival Motor Neuron 1 gene resulting in the loss of the SMN protein. This causes muscle atrophy eventually making motor functions like walking, sitting, breathing, and swallowing difficult. SMA classification has been controversial, but in 1992 the International SMA Consortium defined categories based on age of onset and death. These categories are separated into Mild, Intermediate, and Severe with likelihood of death in childhood increasing respectively. Overall mortality, even in the mild group, remains high.
The recent development of the gene therapy Spinraza has given hope for better quality of life and longer survival. Spinraza is a short string of synthetic genetic material aimed to produce more SMN protein. The Spinraza injections are given intrathecally and must follow a strict, frequent schedule as follows: injection 1, 2, and 3 are given 14 days apart and injection 4 is given 30 days after injection 3. These children receive subsequent injections every 4 months for the rest of their lives. Each individual Spinraza vial costs $125,000, amounting to $750,000 for the first year and $375,000 per year after. The combination of a fragile patient requiring numerous expensive spinal injections necessitates optimal anesthetic conditions to help facilitate a successful procedure.
Considering SMA patients commonly succumb to a fate of dependence on mechanical ventilation, choosing the appropriate anesthetic can be challenging. Although minimally invasive and relatively short, the frequency of injections as well as general pulmonary incompetence of many patients may lead to a host of negative outcomes. Adverse events include: respiratory infection, post-lumbar puncture headache, back pain, and constipation. An anesthetic plan should be developed with the goal of reduction and management of the most common adverse events related to the individual's clinical condition.
For patients with SMA, each anesthetic should include appropriate airway support and intravenous access. Having the patient remain still while maintaining adequate ventilation increases the likelihood of a timely and proficient intrathecal injection. Patients with mild disease may tolerate an anesthetic while breathing spontaneously with supplemental oxygen. Patients with intermediate or severe disease may require more aggressive airway management like positive pressure ventilation with a mask, LMA, or endotracheal tube.
It is crucial to recognize if patient movement or position is making the procedure difficult before any loss of Spinraza occurs during injection attempts. These patients will likely present with a wide spectrum of SMA comorbidities and it is the anesthesiologist’s responsibility to be familiar with these and address them appropriately.
1. Chung, B., Wong, V., Ip, P. Spinal Muscular Atrophy: Survival Pattern and Functional Status. Pediatrics. 2004; 114(5): 548 – 553.
2. Prakash, V. Spinraza – a rare disease success story. Gene Therapy. 2017; 24: 497.
3. Weintraub, A. (2017, March 13). Biogen's Spinraza sparks pricing concerns. http://www.fiercepharma.com
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