Semmelweis University

Obesity hypoventilation syndrome Optimizing patient identification and long-term therapy

Baglyas Szabolcs

Clinical Medicine

Dr. Reusz György

SE Transzplantációs és Sebészeti Klinika I.em tanterem

2024-09-04 09:00:00

Pulmonology

Dr. Losonczy György

Dr. Lorx András

Dr. Eszes Noémi

Dr. Balogh Ádám

Dr. Rényi-Vámos Ferenc István

Dr. Smudla Anikó

Dr. Iványi Zsolt

Despite the facts that respiratory support can decrease the significant mortality and morbidity associated with OHS, and that the financial and therapeutic conditions have been established in Hungary for almost a decade, this syndrome is still frequently undiagnosed and remains inadequately managed. There is an urgent need to draw attention to this population of patients. Increased vigilance of clinicians can lead to early recognition of the syndrome and initiation of appropriate therapy. Untreated OHS is associated with increased use of health-care resources including ICU admission and need for respiratory support. As our results have shown, OHS suspected patients have a high prevalence in Hungarian ICUs and are associated with a high mortality rate. This phenomenon is worsened by COVID-19 infection but is independent of BMI. Based on our results, ICUs are important sites for flagging patients with symptoms of OHS and ensuring appropriate screening. Initiation of long-term respiratory support may lead to a significant mortality rate reduction in the following years after ICU discharge. As we uncovered, in line with the high ICU prevalence, most Hungarian patients start long term respiratory support after an acute respiratory failure hospitalization. Despite this, a protocol based long-term respiratory support program with close monitoring of patients leads to excellent adherence to therapy, and it can improve clinical outcome. According to our results, the five-year cumulative survival of OHS patients treated with long term respiratory support is comparable to international rates in Hungary. Although the syndrome has been extensively studied, the complex pathophysiology of OHS requires further exploration. As our results show, expiratory flow limitation, a surrogate marker of absolute lung volume reduction, is identifiable using oscillometry during calm tidal breathing in OHS patients, especially in the supine position. Our results demonstrate that by monitoring tEFL during the stepwise augmentation of airway pressure, an optimal CPAP level can be identified. Thus, the general application of intra-breath oscillometry during CPAP initiation may help optimize respiratory support setup in OHS patients, which so far is not well-defined in practice guidelines. Despite frequent glottal interference, a selection of intra-breath oscillometry values appear to be reliable indicators of small airway dynamics during CPAP measurements.