Anesthesia and perioperative medical management of children with spinal muscular atrophy

Clinical characteristics and anaesthetic management of severe scoliosis patients with spinal muscular atrophy: case series

Introduction and importance

There is no expert consensus or guidance on perioperative anaesthesia management for spinal surgery of spinal muscular atrophy (SMA) patients with severe scoliosis (Cobb≧90°). We provide a comprehensive summary of the perioperative characteristics observed in patients with SMA and propose an optimized perioperative management strategy for anaesthesia.

Methods

This study is a retrospective single-centre research. Twenty-six SMA patients with severe scoliosis underwent posterior spinal fusion surgery from September 2019 to September 2022 were enroled. The main outcomes were to show the patients' characteristics in anaesthesia, intra- and post-operative periods.

Outcomes

Nineteen patients underwent awake transnasal/transairway intubation. The median anaesthesia time of 25 patients treated under total intravenous anaesthesia was 425 min. After operation, the Cobb angle and correction rate in the coronal plane were median 54.0° and 54.4%. The length of mechanical ventilation with endotracheal intubation in ICU was median 17.5 h in 8 patients. The ICU length of stay of postoperative hospital was median 19 days. Postoperative pneumonia developed in nine patients, atelectasis in two patients, and pleural effusion in six patients. All patients did not need special oxygen therapy after discharge.

Conclusion

Multidisciplinary consultation, lung-protective ventilation strategy, appropriate anaesthetic drugs and reasonable blood transfusion scheme and postoperative monitoring were important in anaesthesia, intraoperative and postoperative periods in the patients of severe scoliosis with spinal muscular atrophy.

Surgical correction of a ventricular septal defect in a child with spinal muscular atrophy type 2 treated with nusinersen sodium: a case report

INTRODUCTION

Spinal muscular atrophy (SMA) is a severe, inherited neuromuscular disorder characterized by progressive muscle weakness and atrophy. Cardiac pathology co-existence is reported more frequently in the severely affected patient groups. Structural heart anomalies, mainly septal, and outflow tract defects are commonly observed pathologies.

CASE PRESENTATION

We herein report the case of a 23 days-old female patient with the diagnosis of spinal muscular atrophy type 2 complicated with structural heart defects. Successful pulmonary banding, and at the age of 17 months, subsequent surgical atrial and ventricular septal defect closure were performed on our patient who was under treatment of Nusinersen Sodium. Post-operative recovery was uncomplicated. Cardiac assessments were normal, and the patient was neurologically improving in her recent follow-up.

CONCLUSION

In the literature, there are no reported cases of successful surgical repair of heart defects in spinal muscular atrophy patients. These patients can be perceived as risky surgical candidates with suboptimal postoperative recovery given the unfavorable disease prognosis of SMA in untreated patients. We report our promising experience with a SMA type 2 patient undergoing a disease-modifying medical treatment. The SMA patients under treatment may be potential candidates for successful surgical cardiac correction given their overall improved prognosis.

Anaesthetic considerations in posterior instrumentation of scoliosis due to spinal muscular atrophy: Case series of 56 operated patients

BACKGROUND

Spinal muscular atrophy (SMA) is a rare illness that often leads to severe kyphoscoliosis. This case series adds to the heretofore sparse information as regards the anaesthetic management of SMA scoliosis patients.

METHODS

This retrospective study reviewed the charts of 79 SMA patients (type II n = 34 and type III n = 45) presenting for possible scoliosis surgery during the time period 2007-2019. Special attention focused on preoperative assessment and clearance requirements, anaesthesia protocol and postoperative handling.

RESULTS

Out of 79 patients, 17 did not receive clearance for the procedure mostly due to grave respiratory insufficiency. Out of 62 patients with clearance for both surgery and anaesthesia, 56 patients [44 females, 12 males; age mean ± SD (range) 22 ± 7.3 (10-40) years] underwent the procedure. Their forced vital capacity and forced expiratory volume in 1 s were mean ± SD (range) 1.41 ± 0.53 (0.61-2.65) L and 1.26 ± 0.47 (0.52-2.27) L, respectively. Intubation difficulties and their resolution, e.g. with the help of fibreoptic technique and video laryngoscopy, are described. All 56 patients were extubated in the operating room postoperativley. Patients stayed at the postanaesthesia care unit for one (n = 48) or two (n = 8) nights. A considerable amount of the patients (19/56) developed hypokalaemia postoperatively.

CONCLUSION

This analysis is one of the bigger series of its kind and adds insight into the preoperative clearance process, the anaesthetic protocol and some of the postoperative complications, e.g. the tendency for developing postoperative hypokalaemia which has not been reported previously.

A case series of paediatric patients with spinal muscular atrophy type I undergoing scoliosis correction surgery

Spinal muscular atrophy is a neuromuscular disorder with degeneration of spinal motor neurons. Type I is a severe variant that was recently shown to be amenable to treatment with the antisense oligonucleotide nusinersen. As a result of increased life expectancy with this treatment, more children with spinal muscular atrophy type I are presenting for spinal correction surgery. In this case series, we present four such patients who underwent spinal surgery at our institution over the course of one year. Pre-operative assessment showed evidence of reduced respiratory function requiring nocturnal non-invasive ventilation in all four patients. A difficult airway was encountered in two of the four patients. Postoperative complications were ubiquitous and included CSF leak, poor wound healing, metal frame exposure, frame instability and wound infection. There were no postoperative respiratory complications and all four children returned to their respiratory baseline postoperatively. All patients underwent successful lumbar puncture and intrathecal nusinersen injection following their spinal surgeries. Given the risk of complications and prolonged recovery following spinal surgery, a detailed family discussion is advisable.

Perioperative management of children with neuromuscular disorders based on a common protocol: A prospective, national study in Italy

BACKGROUND

Children with neuromuscular diseases (NMDs) often display respiratory muscle weakness which increases the risk of postoperative pulmonary complications (PPCs) after general anaesthesia. Non-invasive ventilation (NIV) associated with mechanical insufflation-exsufflation (MI-E) can reduce the incidence and severity of PPCs. The aim of this study was to report our experience with a shared perioperative protocol that consists in using NIV combined with MI-E to improve the postoperative outcome of NMD children (IT-NEUMA-Ped).

METHOD

We conducted a multicentre, observational study on 167 consecutive paediatric patients with NMDs undergoing anaesthesia from December 2015 to December 2018 in a network of 13 Italian hospitals.

RESULTS

We found that 89% of the 167 children (mean age 8 years old) were at high risk of PPCs, due to the presence of at least one respiratory risk factor. In particular, 51% of them had preoperative ventilatory support dependence. Only 14 (8%) patients developed PPCs, and only two patients needed tracheostomy. Average hospital length of stay (LOS) was 6 (2-14) days. The study population was stratified according to preoperative respiratory devices dependency and invasiveness of the procedure. Patients with preoperative ventilatory support dependence showed significantly higher intensive care unit (ICU) admission rate and longer hospital LOS.

CONCLUSION

Disease severity seems to be more related to the outcome of this population than invasiveness of procedures. NIV combined with MI-E can help in preventing and resolve PPCs.

Computed tomography-guided transforaminal lumbar puncture using local anesthesia and a straight 22-gauge spinal needle for intrathecal nusinersen in adults: Findings in 77 procedures

BACKGROUND

Intrathecal nusinersen is the first Food and Drug Administration-approved treatment for spinal muscular atrophy. Reliable intrathecal access is critical for initial and maintenance therapy; however, this can be challenging in older patients with spinal muscular atrophy many of whom have had prior lumbar instrumentation and osseous fusion. Transforaminal lumbar punctures have emerged as a technique for intrathecal access that avoids the hazards of cervical punctures. We describe our technique for transforaminal lumbar punctures under computed tomography guidance using local anesthesia and a straight 22-gauge needle.

METHODS

Following local institutional review board approval, medical records of all patients undergoing computed tomography-guided transforaminal lumbar puncture for intrathecal nusinersen injection were obtained and analyzed. The rate of technical success and immediate complications were recorded. Any delayed complications noted in a 3-day follow-up phone call and future office visit were also recorded. Data collation and analysis were performed using Excel.

RESULTS

A total of 77 transforaminal lumbar punctures were performed with intrathecal administration of nusinersen, for a 100% technical success rate. Local anesthesia was used in 76 cases, with conscious sedation used in one case. General anesthesia was not used in any case. There were no major complications. One patient had a postdural puncture headache that resolved completely after a transforaminal epidural blood patch performed 4 days later.

CONCLUSIONS

Intrathecal administration of nusinersen is critical for treatment of patients with spinal muscular atrophy. Our described technique allows for reliable access to the intrathecal space using local anesthesia and a straight 22-gauge spinal needle under computed tomography guidance, and is easily reproducible.

Successful Combination of Neuraxial and Regional Anesthesia in a Child With Advanced Spinal Muscular Atrophy Type 1 Receiving Maintenance Nusinersen Therapy: A Case Report

Spinal muscular atrophy (SMA) is an autosomal recessive condition characterized by degeneration of the anterior horn cells of the spinal cord, which causes progressive muscle atrophy and weakness. SMA type 1 is the most common type and is associated with severe disability and early mortality. Concomitant restrictive respiratory physiology often manifests with significant implications for anesthetic management. Here, we describe a successful spinal anesthetic for orthopedic surgery in an SMA type 1 patient receiving intrathecal nusinersen maintenance therapy, an antisense oligonucleotide designed to increase expression of the survival motor neuron protein, and the first US Food and Drug Administration-approved drug to treat SMA.

Regional anesthesia in pediatric patients with preexisting neurological disease

Preexisting neurological disease in pediatric patients presents unique challenges to the anesthesiologist. In-depth knowledge of the disease processes and awareness of sequalae that uniquely influence the risks and benefits of anesthetics are needed to make informed decisions. Because these vulnerable populations are often susceptible to perioperative airway or cardiopulmonary complications, the use of regional anesthesia can be advantageous. However, these clinical conditions already involve compromised neural tissue and, as such, create additional concern that regional anesthesia may result in new or worsened deficits. The following discussion is not intended to be a full review of each disease process, but rather provides a concise, yet thorough, discussion of the available literature on regional anesthesia in the more common, but still rare, pediatric neurological disorders. We aim to provide a framework for pediatric anesthesiologists to reengage in a healthy discussion about the risks and benefits of utilizing regional anesthesia in this vulnerable population.

Anaesthesiological approach to the floppy child

Children with symptoms of hypotonia (reduction of postural tone of lower limbs and trunk with or without changes in phasic tone) are frequently anaesthetized for diagnostic and therapeutic interventions. This review outlines the underlying causes and classifications, and the anaesthesiologic pre- and peri-operative management of hypotonic children. Hypotonia may have a large range of aetiologies that be categorized into central and/or peripheral hypotonia. A multidisciplinary approach towards the (differential) diagnosis of the underlying cause of the symptoms in cooperation with a paediatrician and/or paediatric neurologist is emphasized. Anaesthetic management involves the anticipation of an increased risk in difficult airway management because of macroglossia, reduced mouth opening, obesity and limited neck mobility, which increases with age. There are no specific restrictions towards the use of intravenous or inhalational anaesthetics. Short acting opioids and hypnotics, avoiding neuromuscular blockade, and locoregional techniques are preferred. Most patients are sensitive to the cardiac and depressive effects of anaesthetics and all dystrophic myopathies are considered at risk of malignant hyperthermia. Depolarizing neuromuscular blockers are contraindicated. The use of a peripheral nerve stimulator is recommended to detect the severity of muscle relaxation before extubating. Accurate control and management of IV fluids, electrolytes and temperature is mandatory. Adequate postoperative pain treatment is essential to limit stress and metabolic alteration. Preferably a locoregional technique is used to reduce the increased risk of respiratory depression. A multidisciplinary preoperative approach taking into account the differential diagnosis of the underlying disease of the floppy child is recommended.

Peri-operative management of children with spinal muscular atrophy

Background and Aims:

Current multi-disciplinary management of children with spinal muscular atrophy (SMA) often requires the surgical management of spinal deformities. We present the outcomes of our peri-operative experience around the time of their spinal surgery and share our neuromuscular perioperative protocol.

Methods:

A single-centre retrospective chart review was performed to evaluate all children with SMA types I and II that underwent thoracolumbar spinal deformity correction (posterior spinal fusion or growing rod insertion) from 1990 to 2015. Electronic medical records were reviewed to assess pre-operative, intraoperative, and postoperative variables. T-tests, Wilcoxon Rank Sum, Fisher's Exact tests were performed as appropriate.

Results:

Twelve SMA I and twenty-two SMA II patients were included. Type I patients tended to be smaller and had a higher percentage (36.4% vs 4.5%) of American Society of Anesthesiologists (ASA) class 4 patients. Preoperative total parenteral nutrition (TPN) was utilised in 75.0% of type I and 18.2% type II patients. A difficult intubation was experienced in around 25% of the patients (20.0% SMA I, 27.3% SMA II). Approximately two hours of anaesthetic time was required in addition to the actual surgical time in both types. The intensive care unit (ICU) length of stay averaged 6 (4.0-7.5) days for type I and 3 (3-5) days for type II (p = 0.144). Average post-operative length of stay was (8 (7-9) vs. 7 (6-8)) P = 1.0.

Conclusion:

Children with type I and II SMA have similar hospital courses. The surgical and anaesthesia team should consider perioperative TPN and NIPPV (non-invasive positive-pressure ventilation), anticipate difficult intubations, longer than usual anaesthetic times, and potentially longer ICU stays in both SMA type I and II.

Is prophylactic formal fusion with implant revision necessary in non-ambulatory children with spinal muscular atrophy and growing rods who are no longer lengthened?

STUDY DESIGN

Single center, retrospective chart review.

OBJECTIVES

To determine if routine posterior spinal fusion (PSF) is unnecessary in non-ambulatory growing rod graduates with SMA. Most non-ambulatory children with SMA develop early-onset scoliosis (EOS). Posterior growing rods (GR) have been shown safe and effective in managing spinal deformities in these children. The best management of these children, once graduated from their GR, is currently unknown. In this study, we report the clinical results of managing these children without routine definitive fusion following a course of GR treatment.

METHODS

A single-center, retrospective chart and radiographic review was performed on children with SMA treated with posterior distraction GR, with a two-year minimum follow-up since final lengthening. Electronic medical records and radiographs were reviewed for demographic variables, Cobb measurements, implant revisions, occult radiographic implant failure, symptomatic failure, and/or conversion to PSF.

RESULT

12 patients (2 type 1, 9 type 2, 1 type 1/2) met inclusion criteria. Mean age at growing rod insertion was 6.2 years of age (range 4.1-8.2) and age at final lengthening 10.3 years of age (range 9.3-11.9). The mean time between last lengthening and latest clinical or radiographic review was 5.5 (range 2.1-9.0) years. Average mean pre, post, final Cobb angles were 71°, 27° (p < 0.001), 25°. Following final lengthening, only one patient required hardware revision and conversion to definitive fusion in attempts to alleviate chronic hip pain, which was unsuccessful. One additional patient was found to have an occult rod failure that has not required treatment.

CONCLUSION

While limited by sample size, this single-center cohort of non-ambulatory SMA patients with EOS treated with similar constructs suggests that routine, definitive fusion in SMA GR graduates may be unnecessary.

LEVEL OF EVIDENCE

Level IV.

Combined noninvasive ventilation and mechanical insufflator-exsufflator for acute respiratory failure in patients with neuromuscular disease: effectiveness and outcome predictors

Background:

To determine the effectiveness of combined noninvasive ventilation (NIV) and mechanical insufflator-exsufflator (MI-E) for acute respiratory failure (ARF) in patients with neuromuscular disease (NMD), and outcome predictors.

Methods:

A prospectively observational study of patients with ARF was conducted in a pediatric intensive care unit (PICU). All received combined NIV/MI-E during PICU stays between 2007 and 2017. Pertinent clinical variables of heart rate (HR), respiratory rate (RR), pH, PaCO₂, and PaO₂/FiO₂ ratio were collected at baseline and at 2 h, 4-8 h, and 12-24 h after initiating use of NIV/MI-E. Treatment success was defined as avoiding intubation.

Results:

A total of 62 ARF episodes in 56 patients with NMD (median age, 13 years) were enrolled. The most frequent underlying NMD was spinal muscular atrophy (32/62, 52%). ARF was primarily due to pneumonia (65%). The treatment success rate was 86%. PICU stay and hospitalization were shorter in the success group (9.4 ± 6.1 vs. 21.9 ± 13.9 days and 16.3 ± 7.8 vs. 33.6 ± 17.9 days, respectively; both p < 0.05). HR, RR, pH, and PaCO₂ showed a progressive improvement, particularly after 4 h following successful NIV/MI-E treatment. RR decrease at 4 h, and pH increase and PaCO₂ decrease at 4-8 h might predict success of NIV/MI-E treatment. The multivariate analysis identified PaCO₂ at 4-8 h of 58.0 mmHg as an outcome predictor of NIV/MI-E treatment.

Conclusions:

Applying combined NIV/MI-E in the acute care setting is an efficient means of averting intubation in NMD patients with ARF. Clinical features within 8 h of the institution may predict treatment outcome.

The reviews of this paper are available via the supplemental material section.

Cost-effectiveness analysis of using onasemnogene abeparvocec (AVXS-101) in spinal muscular atrophy type 1 patients

Background: Spinal muscular atrophy type 1 (SMA1) is a devastating genetic disease for which gene-replacement therapy may bring substantial survival and quality of life benefits. Objective: This study investigated the cost-effectiveness of onasemnogene abeparvovec (AVXS-101) gene-replacement therapy for SMA1. Study design: A Markov model was used to estimate the incremental cost-effectiveness ratio (ICER), expressed as cost/quality-adjusted life year ($/QALY), of AVXS-101 versus nusinersen over a lifetime. Survival, healthcare costs and QALYs were estimated using natural history data for SMA patients who achieved motor milestones (sitting/walking). Health utility weights were obtained from the CHERISH trial. Setting: USA; commercial payer perspective Participants: SMA1 infants Interventions: AVXS-101 was compared to nusinersen. Main outcome measure: The primary outcome was the ICER. Results: Expected survival (undiscounted) over a lifetime predicted by the model was 37.20 life years for AVXS-101 and 9.68 for nusinersen (discounted QALYs, 15.65 and 5.29, respectively). Using a potential AVXS-101 price range ($2.5-5.0M/treatment), the average lifetime cost/patient was $4.2-6.6M for AVXS-101 and $6.3M for nusinersen. The ICER range was (-$203,072) to $31,379 per QALY gained for AVXS-101 versus nusinersen, indicating that AVXS-101 was cost-effective with prices of ≤$5M. Conclusion: Single-dose AVXS-101 was cost-effective compared to chronic nusinersen for SMA1 patients.

Intensive Care Management of the Neuromuscular Patient

Neuromuscular emergencies are a distinct group of acute neurological diseases with distinct characteristic presentations. Patients who suffer from this group of diseases are at immediate risk of losing protection of their native airway as well as aspirating orogastric contents. This is secondary to weakness of the muscles of the oropharynx and respiratory muscles. Although some neuromuscular emergencies such as myasthenia gravis or Guillain-Barré syndrome are well understood, others such as critical illness myopathy and neuropathy are less well characterized. In this chapter, we have discussed the pathophysiology, diagnostic evaluation, and management options in patients who are admitted to the intensive care unit. We have also emphasized the importance of a thorough understanding of the use of pharmacological anesthetic agents in this patient population.

A retrospective cohort study of children with spinal muscular atrophy type 2 receiving anesthesia for intrathecal administration of nusinersen

INTRODUCTION

Spinal muscular atrophy is characterized by loss of motor neurons in the anterior horn of the spinal cord with resultant proximal muscle weakness. Intrathecal nusinersen has revolutionized the treatment of spinal muscular atrophy. We reviewed the perioperative care of 61 anesthetics performed on eight patients with spinal muscular atrophy type 2 who received nusinersen over 30 months in conjunction with nusinersen's phase 3 clinical trials.

METHODS

Anesthesia was induced in all patients with sevoflurane, nitrous oxide, and oxygen (30%) via facemask. A peripheral intravenous line was placed after the loss of consciousness in all but three procedures. General anesthesia was maintained in 58 anesthetics with a propofol infusion at 250-300 μg/kg/min, while the remainder was maintained with inhalational anesthetics. The airway was managed via facemask or nasal cannula in all but two procedures, in whom a laryngeal mask airway was placed. We analyzed patient demographics, duration of anesthesia and of postanesthesia care unit stay, discharge destination, preprocedure oxygen saturation (SaO₂ ), postanesthesia care unit discharge oxygen saturation, and occurrence of unanticipated admission or postdischarge hospitalization.

RESULTS

Eight American Society of Anesthesiologists physical status three patients (3 male: 5 female) with a median age of 4.1 (2.1-7.8) years and median weight of 13.2 (10-24.7) kg, underwent 61 anesthetics for nusinersen administration or sham procedure. There were no intraoperative anesthetic complications of unanticipated cardiovascular instability, major neurologic events, respiratory failure, or death. Anesthesiologists performed 83% of the procedures.

CONCLUSION

Nusinersen has revolutionized the care of patients with spinal muscular atrophy type 2 and anesthesiologists will be involved in its administration. We found that routine anesthetic care was safe and effective.

Preliminary Safety and Tolerability of a Novel Subcutaneous Intrathecal Catheter System for Repeated Outpatient Dosing of Nusinersen to Children and Adults With Spinal Muscular Atrophy

BACKGROUND

Many patients with spinal muscular atrophy (SMA) who might benefit from intrathecal antisense oligonucleotide (nusinersen) therapy have scoliosis or spinal fusion that precludes safe drug delivery. To circumvent spinal pathology, we designed a novel subcutaneous intrathecal catheter (SIC) system by connecting an intrathecal catheter to an implantable infusion port.

METHODS

Device safety and tolerability were tested in 10 SMA patients (age, 5.4 to 30.5 y; 80% with 3 copies of SMN2); each received 3 sequential doses of nusinersen (n=30 doses). Pretreatment disease burden was evaluated using the Revised Hammersmith Scale, dynamometry, National Institutes of Health pegboard, pulmonary function testing, electromyography, and 2 health-related quality of life tools.

RESULTS

Device implantation took ≤2 hours and was well tolerated. All outpatient nusinersen doses were successfully administered via SIC within 20 minutes on the first attempt, and required no regional or systemic analgesia, cognitive distraction, ultrasound guidance, respiratory precautions, or sedation. Cerebrospinal fluid withdrawn from the SIC had normal levels of glucose and protein; cerebrospinal fluid white blood cells were slightly elevated in 2 (22%) of 9 specimens (median, 1 cell/µL; range, 0 to 12 cells/µL) and red blood cells were detected in 7 (78%) specimens (median, 4; range, 0 to 2930 cells/µL).

DISCUSSION

Preliminary observations reveal the SIC to be relatively safe and well tolerated in SMA patients with advanced disease and spinal fusion. The SIC warrants further study and, if proven effective in larger trials of longer duration, could double the number of patients able to receive nusinersen worldwide while reducing administration costs 5- to 10-fold.

Diagnosis and management of spinal muscular atrophy: Part 2: Pulmonary and acute care; medications, supplements and immunizations; other organ systems; and ethics

This is the second half of a two-part document updating the standard of care recommendations for spinal muscular atrophy published in 2007. This part includes updated recommendations on pulmonary management and acute care issues, and topics that have emerged in the last few years such as other organ involvement in the severe forms of spinal muscular atrophy and the role of medications. Ethical issues and the choice of palliative versus supportive care are also addressed. These recommendations are becoming increasingly relevant given recent clinical trials and the prospect that commercially available therapies will likely change the survival and natural history of this disease.

Proximal spinal muscular atrophy: current orthopedic perspective

Spinal muscular atrophy (SMA) is a hereditary neuromuscular disease of lower motor neurons that is caused by a defective “survival motor neuron” (SMN) protein that is mainly associated with proximal progressive muscle weakness and atrophy. Although SMA involves a wide range of disease severity and a high mortality and morbidity rate, recent advances in multidisciplinary supportive care have enhanced quality of life and life expectancy. Active research for possible treatment options has become possible since the disease-causing gene defect was identified in 1995. Nevertheless, a causal therapy is not available at present, and therapeutic management of SMA remains challenging; the prolonged survival is increasing, especially orthopedic, respiratory and nutritive problems. This review focuses on orthopedic management of the disease, with discussion of key aspects that include scoliosis, muscular contractures, hip joint disorders, fractures, technical devices, and a comparative approach of conservative and surgical treatment. Also emphasized are associated complications including respiratory involvement, perioperative care and anesthesia, nutrition problems, and rehabilitation. The SMA disease course can be greatly improved with adequate therapy with established orthopedic procedures in a multidisciplinary therapeutic approach.

Anesthesia and spinal muscle atrophy

Spinal muscle atrophy (SMA) is autosomal recessive and one of the most common inherited lethal diseases in childhood. The spectrum of symptoms of SMA is continuous and varies from neonatal death to progressive symmetrical muscle weakness first appearing in adulthood. The disease is produced by degeneration of spinal motor neurons and can be described in three or more categories: SMA I with onset of symptoms before 6 months of age; SMAII with onset between 6 and 18 months and SMA III, which presents later in childhood. Genetics: The disease is in more than 95% of cases caused by a homozygous deletion in survival motor neuron gene 1 (SMN1).

PATHOPHYSIOLOGY

The loss of full-length functioning SMN protein leads to a degeneration of anterior spinal motor neurons which causes muscle weakness. Anesthetic risks: Airway: Tracheal intubation can be difficult. Respiration: Infants with SMA I almost always need postoperative respiratory support. Patients with SMA II sometimes need support, while SMA III patients seldom need support. Circulation: Circulatory problems during anesthesia are rare. Anesthetic drugs: Neuromuscular blockers: Patients with SMA may display increased sensitivity to and prolonged effect of nondepolarizing neuromuscular blockers. Intubation without muscle relaxation should be considered. Succinylcholine should be avoided. Opioids: These should be titrated carefully. Anesthetic techniques: All types of anesthetic technique have been used. Although none is absolutely contraindicated, none is perfect: anesthesia must be individualized.

CONCLUSION

The perioperative risks can be considerable and are mainly related to the respiratory system, from respiratory failure to difficult/impossible intubation.

Sugammadex reversal of rocuronium-induced neuromuscular blockade in two types of neuromuscular disorders: Myotonic dystrophy and spinal muscular atrophy

Neuromuscular disorders like myotonic dystrophy (dystrophia myotonica or Steinert's disease) and spinal muscular atrophy are associated with perioperative complications related to muscle weakness. These patients have an increased sensitivity to non-depolarising neuromuscular blocking agents, which can lead to postoperative residual curarization (PORC) and its associated respiratory complications. Adequate reversal of neuromuscular blockade is essential to prevent this. Sugammadex is the first selective relaxant binding agent and it reverses rocuronium- and vecuronium-induced neuromuscular block. Two cases are reported in which the patients received sugammadex to reverse a rocuronium-induced neuromuscular block. Reversal of the rocuronium-induced neuromuscular block (NMB) in both cases was fast, effective and without recurarization, and no safety concerns were observed.