Model identifies causes of nasal drying during pressurised breathing

Impact of posture and CPAP on nasal airflow

Obstructive sleep apnea (OSA) patients who use continuous positive airway pressure (CPAP) often complain of nasal dryness and nasal obstruction as side effects of CPAP. The physiological mechanisms by which CPAP may cause nasal dryness and nasal obstruction remain poorly understood. It has been hypothesized that CPAP interferes with the nasal cycle, abolishing the resting phase of the cycle and leading to nasal dryness. We performed rhinomanometry measurements in 31 OSA patients sitting, laid supine, and supine after 10 min of CPAP at 10 cmH2O. A posture change from sitting to supine led to more symmetric airflow partitioning between the left and right nostrils in the supine position. CPAP did not have a significant impact on nasal resistance, unilateral airflows, or airflow partitioning. Our results suggest that airflow partitioning becomes more symmetric immediately after changing to a supine position, while CPAP had no effect on nasal airflow, thus preserving the nearly symmetric airflow partitioning achieved after the posture change.

[Factors affecting adherence to CPAP therapy in patients with obstructive sleep apnea syndrome]

OBJECTIVE

Analysis of factors affecting adherence to continuous positive airway pressure (CPAP) therapy in patients with obstructive sleep apnea (OSA).

MATERIAL AND METHODS

The literature search was carried out using the databases PubMED, Google Scholar, E-library, Cyberleninka for the period 2013-2023 and included reviews and original articles.

RESULTS

The main groups of factors affecting adherence to CPAP therapy in patients with OSA have been established. These include sociodemographic and socioeconomic factors, the severity of OSA and the severity of clinical symptoms, and psychosocial factors. Strategies that can improve adherence were identified (educational technologies for patients, telemedicine technologies, behavioral therapy, modern technical interventions).

CONCLUSION

Factors that improve adherence to CPAP therapy are high levels of education and income, more severe OSA forms accompanied by daytime sleepiness, support from the patient's spouse and social support. Factors such as low levels of education and income, smoking, symptoms of depression and hypochondria, as well as side-effects worsen adherence to CPAP therapy, including refusal to continue treatment. It should be noted that all the identified factors are very closely associated with each other, so it is necessary to evaluate them comprehensively in each patient with OSA.

The Utility and Acceptability of a New Noninvasive Ventilatory Assist Device, Rest-Activity Cycler-Positive Airways Pressure, During Exercise in a Population of Healthy Adults: Cohort Study

Background

Noninvasive ventilation has been demonstrated to benefit people who have moderate to severe chronic obstructive pulmonary disease during acute exacerbations. Studies have begun to investigate the effectiveness of noninvasive ventilation during pulmonary rehabilitation to improve outcomes for people with chronic obstructive pulmonary disease; however, the lack of portability and humidification of these devices means their use is limited, especially when performing activities of daily living. A new prototype device, RACer-PAP (rest-activity cycler-positive airways pressure), delivers battery-operated positive airway pressure via a nasal interface while regulating nasal airway apportionment bias, removing the need for supplementary humidification. This device may offer people with chronic obstructive pulmonary disease an improved ability to participate in pulmonary rehabilitation and activities of daily living.

Objective

To assess the feasibility of exercising with the RACer-PAP in situ and the acceptability of the device during exercise in normal, healthy individuals.

Methods

A total of 15 healthy adults were invited to attend 2 exercise sessions, each 1 week apart. Sessions lasted approximately 1 hour and included 2 baseline 6-minute walk distance assessments, once with and once without the RACer-PAP in situ. Vital signs and spirometry results were monitored throughout, and spirometry was performed pre- and posttesting with RACer-PAP. Subjective questionnaires ascertained participant feedback on exercising with the device in situ.

Results

Of the 15 initial participants, 14 (93%) completed both sessions. There were no adverse events associated with exercising with the device in situ. There were no differences in vital signs or 6-minute walk distance whether exercising with or without the device in situ. There were small increases in maximum dyspnea score (on the Borg scale) when exercising with the device in situ (median score 2.0, IQR 0.5-3.0, vs 3.0, IQR 2.0-3.25). There were small increases in forced vital capacity following exercise with the RACer-PAP. None of the participants reported symptoms associated with airway drying. Participant feedback provided recommendations for modifications for the next iteration of the device prior to piloting the device with people with chronic obstructive pulmonary disease.

Conclusions

This study has shown RACer-PAP to be safe and feasible to use during exercise and has provided feedback for modifications to the device to improve its use during exercise. We now propose to consider the application of the device in a small pilot feasibility study to assess the safety, feasibility, and utility of the device in a population of people with moderate to severe chronic obstructive pulmonary disease.

Trial Registration

Australian New Zealand Clinical Trials Registry ACTRN12619000478112; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=375477

Nasal function and CPAP use in patients with obstructive sleep apnoea: a systematic review

PURPOSE

This systematic review was conducted to answer the following 3 questions: 'Does nasal pathology affect CPAP use?', 'What is the effect of CPAP on the nose?' and 'Does treatment of nasal pathology affect CPAP use?'.

METHODS

Pubmed and Scopus databases were searched for articles relevant to the study questions up to October 2020.

RESULTS

Sixty-three articles were selected, of which a majority were observational studies. Most studies identified a correlation between larger nasal cross-sectional area or lower nasal resistance and higher CPAP compliance or lower CPAP pressures; however, nasal symptoms at baseline did not appear to affect CPAP use. The effect of CPAP on the nose remains uncertain: while most studies suggested increased mucosal inflammation with CPAP, those investigating symptoms presented contradictory results, with some reporting an increase and others an improvement in nasal symptoms. Evidence is clearer for nasal surgery leading to an increase in CPAP compliance and a decrease in CPAP pressures, whereas there is little evidence available for the use of topical nasal steroids.

CONCLUSION

There appears to be a link between nasal volumes or nasal resistance and CPAP compliance, an increase in nasal inflammation caused by CPAP and a beneficial effect of nasal surgery on CPAP usage, but no significant effect of CPAP on nasal patency or effect of topical steroids on CPAP compliance. Results are more mitigated with regard to the effect of nasal symptoms on CPAP use and vice versa, and further research in this area would help identify patients who may benefit from additional support or treatment alongside CPAP.

Clinical side effects of continuous positive airway pressure in patients with obstructive sleep apnoea

CPAP is considered the gold standard treatment in OSA and is highly efficacious in controlling OSA symptoms. However, treatment effectiveness is limited because of many factors including low adherence due to side effects. This review highlights the range of side effects associated with CPAP therapy in patients with OSA. This information is important for the initiation of patients onto CPAP as well as their continued care while on treatment, given the increase in non-medically supervised CPAP care models in use globally.