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Password protected site: Laryngeal Paralysis from Intubation Diagrams

Causes of Impaired Vocal Cord Motion

  • Paralysis (RLN, Vagus, SLN, brainstem)
    • RLN compression between inflated cuff of ETT and thyroid cartilage
    • Anatomic studies have shown the anterior branch of the recurrent laryngeal nerve to be vulnerable to the lateral projection of the abducted arytenoid and thyroid cartilage (Cavo 1985; Brandwein 1986)
  • Myopathy/myositis of the intrinsic laryngeal muscles (Yin 1996)
    • Inflammation to the PCA with or without ulceration by nasogastric tube may impair vocal fold mobility (Apostolakis 2001; Landis 1988)
  • Crico-arytenoid arthritis
  • Scarring (fixation of arytenoid to cricoid; fixation of arytenoid to arytenoid)
  • Crico-arytenoid subluxation or dislocation
    • Impaired vocal cord (fold) motion after intubation has been ascribed to subluxation or dislocation of the arytenoid from its position on the cricoid. Contemporary thought identifies subluxation/dislocation is not an adequate explanation for the great majority of cases of impaired vocal cord movement seen after intubation (House 2011).
    • Dislocation refers to complete separation of the cartilaginous surfaces whereas subluxation is a disruption of the normal anatomic contact but with still some residual contact between the joint surfaces.
      • Crico-arytenoid dislocation is rare, and when it occurs it is usually associated with severe laryngeal trauma associated with mucosal disruption.
      • The arytenoid is positioned on a wide joint base supported by the posterior cricoarytenoid ligament and the intrinsic muscles of the larynx
    • Subluxation of the arytenoid occurs commonly in association with laryngeal paralysis.
      • Paralysis of the LCA/TA/PCA and IA muscles may remove the balanced support to the arytenoid that keeps it in its normal anatomic position
      • Crico-arytenoid subluxation may therefore be an expected consequence of laryngeal paralysis

Prognosis

In a prospective analysis (House 2011) of 61 adults with recorded laryngeal exam after extubation (mean duration of 9 days)

  • 100% with some degree of laryngeal injury
    • 95%-97% Arytenoid edema and erythema with interarytenoid edema
    • 89% vocal fold erythema
    • 66% vocal fold edema
    • 34% vocal process ulceration
  • 39% with some degree of vocal fold immobility
    • 54% unilateral, 46% bilateral
    • 71% mild immobility; 29% moderate or severe immobility

Video Example

Differential diagnosis: laryngeal paralysis and (unlikely) arytenoid subluxation

References

Apostolakis LW, Funk GF, Urdaneta LF, McCulloch TM, and Jeyapalan MM: The Nasogastric Tube Syndrome: Two Case Reports and Review of the Literature. Head Neck 2001 Jan:23(1):59-63

Brandwein M, Abramson AL, Shikowitz MJ. Bilateral vocal cord paralysis following endotracheal intubation. Arch Otolaryngol Heada Neck Surg. 1986;112:866-882

Cavo JW:True Vocal Cord Paralysis Following Intubation. Laryngoscope 1985;95:1352-1359

Landis EE, Hoffman HT, Koconis CA: Upper Airway Obstruction Associated With Large Bore Nasogastric Tubes  South Med J 1988 Oct;81(10):1333

Norris BK and Schweinfurth: Arytenoid Dislocation: An Analysis of the Contemporary Literature. Laryngoscope 121:142-146, 2011

House JC, Noordzij JP, Murgia B and Landmore S: Laryngeal INjury from Prolonged Intubation: A Prospective Analysis of Contributing Factors. Laryngoscope 2011 March; 121(3):596-600

Yin SS, Qui WW, Stucker FJ: Value of Electromyography in Differential Diagnosis of Laryngeal Joint Injuries After Intubation. Ann Otol Rhinol Laryngol. 1996;105:446-451