Pijus Ruokis1, Algimantas Žaltauskas1, Gabrielė Baltrūnaitė1
1Medical Academy of the Lithuanian University of Health Sciences
Background. Treatment-emergent central sleep apnea (TECSA) is a central-onset apnea that occurs during initial treatment for obstructive sleep apnea (OSA) and is diagnosed in 0.56-21.3 % of patients treated for OSA. The emergence of TECSA significantly reduces the effectiveness of OSA treatment and patient cooperation.
The aim: to review the pathogenesis, clinic, diagnosis, and treatment of treatment-induced central sleep apnea.
Methods: the literature and data search were performed using PubMed, SpringerLink, ScienceDirect, Lithuanian Academic Library (eLaBa), Google Scholar databases. Published research papers and articles on the pathogenesis, clinic, diagnosis, and treatment of TECSA syndrome were selected, prioritizing the literature in English and Lithuanian, that was not older than 10 years.
Results. Although the exact mechanism of this disorder is unknown, TECSA pathogenesis is thought to be dominated by increased sensitivity of chemoreceptors to hypocapnia, explained by loop gain in combination with increased CO2 clearance by opening the upper airways during CPAP therapy and activating the Hering-Breuer reflex. TECSA presents with typical symptoms of sleep apnea already during treatment of a patient with first line OSA treatment and is diagnosed in a PSG study. TECSA is treated by continuing CPAP therapy at minimum effective pressure or by replacing CPAP therapy with more modern devices (BiPAP or ASV) capable of analyzing the patient’s breathing pattern and adjusting the supplied air pressure accordingly. There is currently no drug treatment for TECSA.
Conclusions: 1. TECSA is a disorder in which episodes of central apnea occur during treatment with OSA due to unstable central respiratory regulation, increased CO2 clearance, and lung tissue strain during CPAP therapy. 2. TECSA presents with typical symptoms of sleep apnea syndrome in the presence of active OMA treatment with positive pressure therapy. 3. TECSA diagnosis is based on a polysomnography, where five or more episodes of central apnea per hour occur after CPAP therapy has resolved obstructive events. 4. The main treatment for TECSA is the continuation of CPAP at minimum effective pressure or the change of therapy to automatic pressure-regulating devices.
Keywords: treatment-emergent central sleep apnea, complex sleep apnea, obstructive sleep apnea, central sleep apnea, CPAP, BiPAP, ASV.