[The Nocturnal Respiratory Rate in COPD Patients of Varying GOLD Severity with/without Nicotine Consumption: Calculation by Means of Breath Sound Analysis]. / Die nächtliche Atemfrequenz bei COPD-Patienten unterschiedlicher GOLD-Schweregrade mit/ohne Nikotinkonsum: Berechnet mittels Atemgeräuschanalyse.

Respiratory rate is an important risk marker and enables early detection of critically ill and vulnerable patients in clinical routine. The aim of this pilot study with 31 patients (COPD severity levels II - IV) was to determine the mean nocturnal respiratory rate based on breath sound recordings and to investigate the dependence of respiratory rate on COPD severity level and smoker status. The mean respiratory rate of the total collective was 19/min. For the COPD-GOLD severity levels, no significant differences in mean respiratory rate could be observed. When nicotine consumption is taken into account, active smokers showed a significantly higher mean respiratory rate of 20.84 ±â€Š4.45/min compared to non-smokers with 17.41 ±â€Š3.14/min (p < 0.05). In addition, active smokers in the study were significantly more frequent among patients with night-time wheezing (60 % vs. 23.8 %). This might suggest that smokers need to perform increased breathing work with increased breathing rate to compensate for oxygen deficiency in bronchial obstruction. The results of the present study show that with the acoustic recording of breath sounds, a reliable representation and calculation of the breath frequency is possible.

[ThorAKUSTIK - a computer-based method to determine the oronasal respiratory flow]. / Bestimmung der Atemstromstärke mithilfe des ThorAKUSTIK-Verfahrens bei Mund- und Nasenatmung.

BACKGROUND: Respiratory flow detection with the aim of detecting sleep-related breathing disorders plays a major role in polysomnography. Due to the fact that pneumotachographs are too bulky and not suitable for measurements during sleep, the ThorAKUSTIK system has been developed. By attaching a noise sensor right next to larynx, it determines the respiratory flow in an acoustic way. METHODS: The ThorAKUSTIK system as well as a pneumotachograph were applied simultaneously. The correlation between those two methods has been calculated. PATIENTS: We investigated twenty male subjects. All of them were non-smokers. RESULTS: The ThorAKUSTIK-System showed a highly positive correlation (r = 0.89 to 0.91; p < 0.01) and was able to measure the respiratory flow in a reliable way. CONCLUSIONS: The ThorAKUSTIK-System allows a long-term live monitoring and has the potential to be used in several clinical departments. Larger studies are necessary to verify the application in the clinical routine.