ILO

Q: 56 years old male who was "fast-tracked" for extubation after an uncomplicated cardiac bypass surgery developed acute upper respiratory distress. Lungs are clear to auscultation, but there is a wheezing at the upper laryngeal (throat) level. What could be the two major differential diagnoses?

Answer: laryngospasm and paradoxical vocal fold motion

The technical term for paradoxical vocal fold motion is Inducible laryngeal obstruction (ILO). It is very common after brief intubation for surgeries but can occur in patients intubated for longer periods. The other terms used are laryngeal dyskinesia, vocal cord dysfunction (VCD), and periodic laryngeal obstruction. It is different from laryngospasm. Similar pathology has been described after exercise, asthma exacerbation, neurologic injuries, and a few other instances. It is characterized by paradoxical vocal fold adduction during inspiration, expiration, or both.

Normally, the vocal folds abduct during inspiration and slightly adduct during expiration, coughing, and speech.

Prompt arrangements should be made for intubation in such instances, but ILO can be witnessed before applying neuromuscular blockade during laryngoscopy. Sometimes, the patient can be salvaged without intubation using inhaled broncho-dilating medications or helium-oxygen mixtures. It should not be delayed to wait for the response.

#procedures

#ENT

#pulmonary

References:

1. Arndt GA, Voth BR. Paradoxical vocal cord motion in the recovery room: a masquerader of pulmonary dysfunction. Can J Anaesth 1996; 43:1249.

2. Hammer G, Schwinn D, Wollman H. Postoperative complications due to paradoxical vocal cord motion. Anesthesiology 1987; 66:686.

3. Harbison J, Dodd J, McNicholas WT. Paradoxical vocal cord motion causing stridor after thyroidectomy. Thorax 2000; 55:533.

4. Larsen B, Caruso LJ, Villariet DB. Paradoxical vocal cord motion: an often misdiagnosed cause of postoperative stridor. J Clin Anesth 2004; 16:230.