Efficacy and safety of inhalation therapy with thermal heliumoxygen mixture in patients with exacerbation of chronic obstructive pulmonary disease complicated by hypoxemic and hypercapnic respiratory failure and secondary pulmonary arterial hypertension

The most formidable complication and the most common reason for hospitalization of patients with chronic obstructive pulmonary disease (COPD) is respiratory failure (RF), in the treatment of which respiratory support is actively used. However, respiratory support is ineffective in 30% of patients with severe exacerbation of COPD combined with hypoxemia and hypercapnia, which necessitates the search for new methods to correct RF. The aim of the study was to determine the efficacy and safety of thermal heliox (t-He/O 2 ) in the treatment of exacerbation of COPD complicated by hypoxemic and hypercapnic RF and secondary pulmonary hypertension (PH) (group III according to the classification of the World Health Organization). Methods. The comparative controlled parallel prospective study included patients ( n = 80: 49 men, 31 women) with exacerbation of COPD of categories C and D according to the criteria of the Global Initiative for Chronic Obstructive Lung Disease (GOLD, 2021 – 2023), complicated by hypoxemic, hypercapnic respiratory failure and PH. The patients ( n = 80) were similar in demographic, clinical and functional parameters and received noninvasive ventilation (NIV) with biphasic positive airway pressure (BiPAP S/T) and oxygen (O 2 ) to maintain hemoglobin oxygen saturation (SpO 2 ) at 95–97% in addition to standard drug therapy. The patients were divided into 2 groups: group 1 ( n = 40: 25 men, 15 women) received t-He/O2 inhalations twice a day for 30 min (a total of 60 min per day); group 2 ( n = 40: 24 men, 16 women) did not receive t-He/O 2 inhalations. The dynamics of the clinical condition of patients, gas exchange in the lungs, acid-base balance, left-to-right shunt fraction, oxygen delivery, integral hemodynamic indices, external respiratory function (ERF), and exercise tolerance (ET) were assessed. Results. When using t-He/O 2 in patients with COPD with hypercapnic, hypoxemic DN and PH against the background of standard therapy, a positive effect was demonstrated not only on the clinical condition of patients, but also on central hemodynamics, as well as a significant improvement in ERF, ET, arterial blood gas composition, acid-base balance and intrapulmonary shunt fraction, partial pressure of oxygen and carbon dioxide in arterial blood, hemoglobin oxygen saturation, as well as the concentration of bicarbonate ions and lactate in arterial blood compared with such indices in patients in the control group. Conclusion. It has been established that t-He/O 2 inhalations in parallel with NIVL are safe and effective compared to oxygen therapy, while improving cardiac function and the clinical condition of patients, reducing the severity of dyspnea and signs of hypoxemia and hypercapnia, increasing the ET due to increased oxygen delivery to tissues, normalizing gas exchange in the lungs, reducing the shunt fraction, and restoring the level of bicarbonates and lactate in the blood.