Unilateral recurrent laryngeal nerve palsy post-thyroidectomy: Looking for hyperventilation syndrome

Area of Science:

• Otolaryngology
• Pulmonology
• Neurology

Background:

• Unilateral Recurrent Laryngeal Nerve (RLN) palsy commonly causes dysphonia and dysphagia.
• The impact of unilateral RLN palsy on dyspnea remains unclear.
• Air leak is hypothesized as a potential cause of Hyperventilation Syndrome (HVS) in RLN palsy.

Purpose of the Study:

• To investigate the association between dyspnea and Hyperventilation Syndrome (HVS) in patients with unilateral RLN palsy.
• To determine if HVS contributes to unexplained dyspnea following thyroidectomy.

Main Methods:

• A cohort of patients with unilateral RLN palsy after thyroidectomy and unexplained dyspnea were evaluated over 12 months.
• Diagnostic assessments included the Nijmegen score, hyperventilation testing, arterial blood gas analysis, lung function tests, and cardiac evaluations.
• Hyperventilation Syndrome (HVS) diagnosis required at least two of the following: Nijmegen score >23, symptom reproduction during hyperventilation, or low end-tidal CO2 (EpCO2) post-hyperventilation.

Main Results:

• Eight out of ten patients (80%) with unilateral RLN palsy and dyspnea following thyroidectomy were diagnosed with HVS.
• These patients exhibited HVS without evidence of cardiac or pulmonary dysfunction.
• The study included patients who underwent thyroidectomy for benign conditions.

Conclusions:

• Hyperventilation Syndrome (HVS) may play a role in the development of dyspnea in patients with unilateral RLN palsy.
• This study provides initial evidence supporting the link between HVS and dyspnea in the context of RLN palsy.
• Further research is warranted to confirm these findings and elucidate the underlying mechanisms.