Background

Patients with Limb Girdle Muscular Dystrophy (LGMD) and other RYR1 variants present unique challenges to the anesthesiologist because of muscle weakness and potential for malignant hyperthermia (MH). We describe the anesthetic management of a patient with LGMD and a potentially difficult airway.

Case Presentation

A 55-year-old male with LGMD and no prior exposure to anesthesia presented for resection of colon cancer. The patient’s LGMD predominantly affected his shoulders. Pre-anesthesia examination and routine blood tests were within normal limits. While LGMD is not associated with difficult airways, there was concern for one because of the patient’s small mouth opening and beak-shaped mouth and jaw. Thus, an awake-fiberoptic intubation was performed and the airway was secured with a 7.0 mm endotracheal tube. The anesthesia team took precautions for MH and used a new anesthesia machine to avoid triggers. In the operating room, the patient was positioned at 45 degrees and semi-reclined. Maintenance of anesthesia was achieved with total intravenous anesthesia (TIVA) with propofol, dexmedetomidine, fentanyl, and paralysis with rocuronium. The patient was managed conservatively in the postoperative period and extubated without incident the following day.

Discussion

Literature on safe anesthetic management of LGMD is limited. In this case report, we highlight the successful use of TIVA in avoiding MH triggers, and the use of awake-fiberoptic intubation as an effective technique for securing a difficult airway in a patient with LGMD. Inhaled anesthetics and succinylcholine are contraindicated in LGMD patients because of an increased risk of developing MH, rhabdomyolysis, and hyperkalemia 1. Using TIVA avoids the triggers of MH while maintaining appropriate anesthetic depth. Interval measurement of lactate and CK are also important in monitoring for development of MH. Dantrolene should be readily available for suspected MH. LGMD increases the risk of respiratory compromise under anesthesia, particularly since muscle relaxants can further exacerbate existing respiratory weakness. Awake-fiberoptic intubation requires thorough pre-anesthesia airway assessment and planning, preserves spontaneous ventilation, and mitigates the risk of respiratory decompensation associated with muscle relaxation, allowing for a controlled and gradual approach to securing the airway. In this case, a thorough airway assessment revealed potential challenges (limited mouth opening, and beak-shaped mouth and jaw) that could have complicated conventional intubation. Anticipation of potential airway challenges and advanced planning for an awake-fiberoptic intubation ensured a safe intubation and successful anesthetic for this patient.