6go6ckt5b8|3000F7576AC3|Tab_Articles|Fulltext|0xf1ff24373a000000bf06000001000400

Merosin-positive congenital muscular dystrophy is a rare genetic disorder characterized by muscle weakness, joint contractures, and delayed motor development [1]. It presents unique challenges in the field of ophthalmology, particularly when surgical interventions such as bilateral facoemulsification and intraocular lens positioning are required in affected children. This article aims to provide a comprehensive overview of the considerations, challenges, and outcomes associated with these procedures in children with merosin-positive congenital muscular dystrophy.

A 6-year-old male child, 17.5 kg, diagnosed with a merosin-positive congenital muscular dystrophy, congenital cataract, central nervous system abnormalities (hypoplasia of the pontin, cerebellum, callous body and frontal lobes and agenesis of the pellucid septum) and myoclonic seizures presented for the correction of the congenital cataract. Neurodevelopment was overdue, important cognitive deficit was present as well as short stature, microcephalia, nystagmus, hypertonia, hyperreflexia and anterior subluxation of the hips. The patient continually received risperidone 1 mg at night and valproic acid 250 mg every twelve hours. No changes in cardiac function were observed on echocardiography. An electroneuromyography showed an electric silence when the muscle was resting and, when stimulated, the muscle fibers were intermittently recruited; many potentials had reduced amplitude and duration. A muscular biopsy showed abnormalities compatible with congenital muscular dystrophy: there was, mainly, modifications in the sarcolemmal membrane, with wrinkling and interruptions and a gap between the sarcolemma and the contractile fibers. Creatine kinase levels were higher, already expected in the congenital muscular dystrophies. No difficult airway predictors were present. In the pre-operative period, a complete evaluation of the patient was carried out together with the genetic, neuropediatric, cardiology and ophthalmology teams. The free and informed consent form was obtained for the anesthetic procedure as well as for the publication of this case report. Before the surgery, the operating theater was prepared for this patient: sevoflurane vaporizer was removed, the ventilator was washed with high oxygen flow for two hours. The anesthetic team performed a total intravenous anesthesia. In the intra-operative period, the patient was monitored with cardioscopy, pulse oximetry, non-invasive blood pressure, core temperature and end tidal carbon dioxide. A peripheral venous access 22G was punctured in the left upper limb. Propofol was administered and a laryngeal mask size 2.5 was placed. Propofol infusion was maintained at a 0.3 µg/kg/min. No neuromuscular blockade was administered during the procedure and spontaneous ventilatory drive was kept. A peribulbar block was performed in the inferolateral region of each eye utilizing a combination of 200 IU hyaluronidase, 80 mg lidocaine and 30 mg bupivacaine. Prophylaxis against nausea and vomiting was administered using 3 mg of ondansetron and 4 mg of dexamethasone. The bilateral phacoemulsification procedure and intraocular lens placement were carried out without any complications. The patient recovered in the ICU bed and was subsequently discharged home after a two-day stay, with no reported complications.

Patients with merosin-positive congenital muscular dystrophy who require surgical procedures, including bilateral facoemulsification and intraocular lens positioning, present unique challenges during anesthetic management [3]. Peri-operative risk assessment in these individuals can be aided by using the muscular impairment rating scale (MIRS), which categorizes patients into five grades based on the severity of muscular involvement [4]. Pre-operative evaluation should include a comprehensive cardiological assessment due to the potential presence of cardiomyopathy and arrhythmias. Additionally, predictors of difficult airway and respiratory compromise should be evaluated in this population. Patients with forced vital capacity (FVC) lower than 50% may require post-operative non-invasive ventilation, and bronchoaspiration prophylaxis should be considered [4].

Opioids are considered safe for analgesia; however, patients with congenital muscular dystrophy are more susceptible to side effects such as respiratory depression, gastrointestinal paresis, and aspiration [5]. In this case report, an opioid-free technique was used, and analgesia was provided through an ocular block. When non-depolarizing muscle relaxants are utilized, neuromuscular monitoring becomes essential to minimize the risk of residual paralysis, which is more common in these patients [5]. It is crucial to administer fluids free of potassium, and potassium levels should be monitored during the procedure [5]. Given the higher risk of post-operative apnea and death, patients with merosin-positive congenital muscular dystrophy should recover in the intensive care unit [7].

The anesthetic management of patients with merosin-positive congenital muscular dystrophy necessitates consideration of their unique characteristics and challenges. A multidisciplinary approach to peri-operative care is crucial, as these patients can be complex to manage. This case report demonstrates a successful anesthetic procedure in a child with merosin-positive congenital muscular dystrophy and aims to provide valuable insights for physicians caring for patients with this extremely rare condition. By sharing our experience, we hope to improve the care and safety of individuals with merosin-positive congenital muscular dystrophy undergoing surgical interventions.

Contributors: GVF: manuscript writing, patient management; MAD, MPM: manuscript editing, patient management; PHTM, LJR: critical inputs into the manuscript. MAD will act as a study guarantor. All authors approved the final version of this manuscript and are responsible for all aspects of this study.

Funding: None; Competing interests: None stated.