Unilateral hypoglossal nerve palsy after the use of laryngeal mask airway (LMA) Protector

Effect of Different Insertion Methods on LMA Protector-Related Complications: A Prospective Randomized Double-Blind Clinical Trail

OBJECTIVE

The authors compared the effect of 2 insertion methods, namely the conventional laryngeal mask airway (LMA) insertion and the index finger-assisted LMA insertion, on the incidence of complications associated with LMA Protector insertion.

METHODS

The authors enrolled 300 patients, who underwent painless bronchoscopy. The patients ranged in age between 18 and 75 and were classified as American Society of Anesthesiologists grade I to III. They were randomly divided into 2 groups: a control group of 150 patients and an assisted group comprising 150 patients. LMA was inserted using the conventional and index finger-assisted insertion methods in both groups, respectively. The primary outcome was postoperative complications, such as oral mucosal injury and pharyngeal pain. Secondary outcomes included the success rate of first-time insertion, the incidence rate of inverse folding of LMA tips, oropharyngeal leak pressure (OLP), and other postoperative complications.

RESULTS

Compared with the conventional LMA insertion method, index finger-assisted LMA insertion can significantly reduce the incidence rate of oral mucosal injury and pharyngeal pain, with fewer insertion failures. There was a statistically significant difference between the 2 groups in the visual field grading before adjustment for LMA alignment (P<0.0001). The conventional insertion method increased the likelihood of inverse folding of LMA tips. When the conventional insertion method was utilized, there was a significant difference in airway pressure and tidal volume before and after alignment under a fiberoptic bronchoscope (P<0.0001), but no significant difference in visual field grading and respiratory mechanics-related indicators.

CONCLUSIONS

Index finger-assisted insertion can significantly reduce the incidence rate of LMA Protector-related complications and inverse folding of LMA tips.

Transient Hypoglossal and Lingual Nerve Injury Following the Use of I-gel Supraglottic Airway: A Case Report

Injury to the hypoglossal and/or lingual nerve is a rare occurrence with the use of a laryngeal mask airway (LMA) or supraglottic airway (SGA) device. There has been one prior report of a lingual and hypoglossal nerve injury with the i-gel™ SGA. We are describing the second reported hypoglossal and lingual transient nerve injury in a male patient while using an i-gel™ SGA. Although excessive cuff pressure has been cited as a possible cause, the i-gel™ does not have a cuff. This report highlights that hypoglossal nerve injury can still occur, even with the use of a cuffless LMA such as the i-gel™ SGA.

Isolated Hypoglossal Nerve Palsy as an Early Symptom of a Granular Cell Tumor

Background: Hypoglossal nerve palsy (HNP) is rather common as a neurological disease. However, as an isolated nerve palsy it is an exceedingly rare phenomenon and points at local pathologies along the peripheral course of the nerve. In this communication we report a granular cell tumor (GCT) arising in the submandibular segment of the hypoglossal nerve. Case-Report: Spontaneous isolated HNP was recognized in a female patient. First line MR-imaging identified a clivus-chordoma. However, involvement of the hypoglossal nerve was highly unlikely according to MR-findings. Finally, ultrasonographic investigation revealed a small submandibular mass which, at histological examination, turned out to be a granular cell tumor arising within the hypoglossal nerve. Conclusions: This is the report of an extremely rare GCT originating within the 12th cranial nerve. The case illustrates that isolated motoric cranial nerve palsy may result from this rare tumor entity. This report also points out the diagnostic value of a simple ultrasonographic investigation to depict pathologic lesions of the submandibular space.

Current landscape in motoneuron regeneration and reconstruction for motor cranial nerve injuries

The intricate anatomy and physiology of cranial nerves have inspired clinicians and scientists to study their roles in the nervous system. Damage to motor cranial nerves may result from a variety of organic or iatrogenic insults and causes devastating functional impairment and disfigurement. Surgical innovations directed towards restoring function to injured motor cranial nerves and their associated organs have evolved to include nerve repair, grafting, substitution, and muscle transposition. In parallel with this progress, research on tissue-engineered constructs, development of bioelectrical interfaces, and modulation of the regenerative milieu through cellular, immunomodulatory, or neurotrophic mechanisms has proliferated to enhance the available repertoire of clinically applicable reconstructive options. Despite these advances, patients continue to suffer from functional limitations relating to inadequate cranial nerve regeneration, aberrant reinnervation, or incomplete recovery of neuromuscular function. These shortfalls have profound quality of life ramifications and provide an impetus to further elucidate mechanisms underlying cranial nerve denervation and to improve repair. In this review, we summarize the literature on reconstruction and regeneration of motor cranial nerves following various injury patterns. We focus on seven cranial nerves with predominantly efferent functions and highlight shared patterns of injuries and clinical manifestations. We also present an overview of the existing reconstructive approaches, from facial reanimation, laryngeal reinnervation, to variations of interposition nerve grafts for reconstruction. We discuss ongoing endeavors to promote nerve regeneration and to suppress aberrant reinnervation and the development of synkinesis. Insights from these studies will shed light on recent progress and new horizons in understanding the biomechanics of peripheral nerve neurobiology, with emphasis on promising strategies for optimizing neural regeneration and identifying future directions in the field of motor cranial neuron research.

Clinical performance of the LMA Protector™ airway in moderately obese patients

Background

The 4th National Audit Project of The Royal College of Anaesthetists and The Difficult Airway Society (NAP4) reported a higher incidence of supraglottic airway device (SAD) related pulmonary aspiration in obese patients especially with the first-generation SADs. The latest single-use SAD, the Protector™ provides a functional separation of the respiratory and digestive tracts and its laryngeal cuff with two ports allowing additional suction in tandem with the insertion of a gastric tube. The laryngeal cuff of LMA Protector™ allows a large catchment reservoir in the event of gastric content aspiration.

Methods

We evaluated the performance characteristics of the LMA Protector™ in 30 unparalysed, moderately obese patients. First attempt insertion rate, time for insertion, oropharyngeal leak pressure (OLP), and incidence of complications were recorded.

Results

We found high first and second attempt insertion rates of 28(93%) and 1(33%) respectively, with one failed attempt where no capnography trace could be detected, presumably from a downfolded device tip. The LMA Protector™ was inserted rapidly in 21.0(4.0) seconds and demonstrated high OLP of 31.8(5.4) cmH2O. Fibreoptic assessment showed a clear view of vocal cords in 93%. The incidence of blood staining on removal of device was 48%, postoperative sore throat 27%, dysphagia 10% and dysphonia 20% (all self-limiting, resolving a few hours postoperatively).

Conclusions

We conclude that the LMA Protector™ was associated with easy, expedient first attempt insertion success, demonstrating high oropharyngeal pressures and good anatomical position in the moderately obese population, with relatively low postoperative airway morbidity.

Trial registration

Australian New Zealand Clinical Trials Registry, ACTRN12617001152314. Registered 7 August 2017.