CHEST Guidelines-Transvenous-Phrenic-Nerve-Stimulation-Induced-Stri

Transvenous-Phrenic-Nerve-Stimulation-Induced-Stri

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This case study explores a novel complication associated with the use of a transvenous phrenic nerve stimulation (TPNS) device in a patient with central sleep apnea (CSA) due to chronic opioid use. CSA involves episodes of insufficient ventilation during sleep caused by a lack of respiratory effort. The TPNS device, specifically the Remede system, helps induce diaphragmatic contractions to restore breathing. However, since its development, there hasn't been a thorough observation of how this induced effort impacts the upper airway.<br /><br />In this report, a 58-year-old woman with severe CSA exhibited inspiratory stridor (a high-pitched wheezing sound) during TPNS therapy, despite a significant reduction in her apnea-hypopnea index (AHI) from 144.47 to 4.5 events per hour. A drug-induced sleep endoscopy (DISE) was employed to visually scrutinize her upper airway, which revealed dynamic collapse of the vocal folds causing stridor. Attempts to adjust TPNS settings did not alleviate the stridor.<br /><br />Various theories might explain the stridor. TPNS may lead to vocal fold adduction, either due to phrenic nerve's effects on reflex mechanisms or as a response to the strong diaphragm contraction induced by the prosthetic stimulation. Alternatively, stridor might occur passively through a process like the Bernoulli effect, as seen in another case of phrenic nerve stimulation obstructing the airway.<br /><br />Ultimately, combining CPAP with TPNS successfully resolved the stridor, improving airflow at a CPAP level of 11 cm H2O. The study suggests the potential for DISE as a diagnostic tool to assess and understand the impact of TPNS on the upper airway in CSA, calling for more research to delineate the relationship between TPNS therapy and upper airway dynamics.

Keywords

transvenous phrenic nerve stimulation

central sleep apnea

chronic opioid use

Remede system

inspiratory stridor

apnea-hypopnea index

drug-induced sleep endoscopy

vocal fold collapse

continuous positive airway pressure

upper airway dynamics