Introduction
Paradoxical vocal fold motion (PVFM) is a phenomenon where inappropriate motion of the vocal cords is seen. Patients often present to the emergency department with symptoms of wheezing, inspiratory stridor and concerns for upper airway obstruction. Patients may have multiple health care provider visits with extensive workup and delays in diagnosis. The disorder is commonly associated with asthma, exercise, post-extubation status, neurologic injury, and psychosocial disorders.
Case Report
Patient is a 35 year-old female with a history of asthma seen in the PACU following laparoscopic appendectomy. While in the PACU, the patient did well, with mild operative site pain treated with 25 mcg of Fentanyl. Subsequently, the patient felt nauseous and became stridulous and dyspneic with SpO2 readings in the 70s while seated in an upright position. Physician anesthesiologists were one bay adjacent and immediately responded, applying 100% oxygen and positive pressure using an Ambu bag with improvement of her stridor and saturations without assistance. Head of the bed was lowered for albuterol SVN therapy and the patient again became stridulous. The head of the bed was then raised, and CPAP re-placed. Albuterol and racemic epinephrine were administered via face mask, as well as lidocaine 25mg IV, and dexamethasone 4mg IV.
The patient improved initially, but worsened. She was given epinephrine 0.3 mg IV, and became tachycardic with short runs of ventricular tachycardia. Ventricular tachycardia resolved without intervention, and the patient’s stridor improved. However, she continued to be extremely anxious, and was administered midazolam 1mg IV.
Nasal fiberoptic examination was performed, showing severe adduction of the bilateral true vocal folds with supraglottic squeezing, and a posterior glottal gap through which she was oxygenating. Laryngeal structures including the arytenoids and true vocal folds were quivering. The bilateral vocal folds were seen to move with phonation and sniffing, allowing for some abduction. Following the fiberoptic examination, CPAP was applied, and the patient was transferred to the ICU.
Discussion
Dyspnea, stridor and hypoxia represent a critical presentation for anesthesia providers, and possible etiologies such as laryngospasm, bilateral vocal cord paresis, and other causes of upper airway obstruction should be considered. Patients presenting with prolonged inspiratory stridor, wheezing and concerns for airway obstruction may benefit from inclusion of PVFM in the provider’s differential diagnosis. The gold standard for diagnosis of PVFM is laryngoscopy, and may be differentiated from laryngospasm by its time course, which is often over hours to days, whereas laryngospasm usually lasts seconds to minutes. Patients with PVFM have increased difficulty with inspiration vs expiration, and minimal response to asthma therapy. If performing pulmonary function tests, patients with PVFM may have a flattened inspiratory flow-volume loop with normal expiratory spirometry, lung volumes, and arterial blood gas measurements. Acutely, patients benefit from reassurance and supportive care with CPAP until spontaneous resolution. Panting and Heliox has been reported to be helpful. Endotracheal intubation and tracheostomy are not indicated in PVFM, and should be used only if other etiologies are suspected. Prevention strategies include minimization of laryngeal irritation, as well speech language pathologist therapy.
