Certain conditions of respiratory assessment affect breathing frequency and awareness

Abstract

Introduction: The evaluation of breathing function may be influenced by the conditions under which it is assessed. This can be of critical importance in both clinical settings and research. This study aims to analyze the effect of different tasks on the breathing pattern.

Methods: 34 healthy subjects (24±2 years, 20 women). Four conditions were assessed: 1. Rest, 2. Cognitive load (CL), 3. Inspiratory load of 15cmH20 (IL), and 4. Both combined (BC). The order of the tasks was randomly defined.  Respiratory rate (RR) was recorded during 3min under each condition with the Kinect V2^®. After each session, breathing discomfort (A1 score of the Multidimensional Dyspnea Profile questionnaire) and the awareness of breathing (AB) with a 10cm AVS were assessed.

Results: The RR was at 15 ±3 / min at rest and increases with the addition of CL to 19 ±3 / min (p<.001) and decreases with IL to 13 ±4 / min, (p<.01) and during BC to 13 ±4 / min, (p<.05). AB was 5.5±2.3 at rest, it decreases with CL (1.5 ± 1.74, p<.001), increases with IC (7.8 ± 2.2, p<.001) and was similar when BC (5.7±2.46, p=.86). A similar trend was observed for A1: Rest (1±0.90), CL (0.5 ± 0.9, p<.01), CI (4.8 ± 2.2, p<001) but on the other hand it increases with BC (4.9 ± 2.2). Awareness and discomfort of breathing are negatively correlated with RR (r=-0.42, p<.001 and r=-0.32, p<.001 respectively).

Measurements and Main Results: Monitoring respiratory pattern by camera increases subject's awareness of breathing and can affects respiratory rate (instrumental effect). Inspiratory load increases discomfort and breathing awareness. The cognitve load does not seem to have a distractive effect on the discomfort but on the breathing awareness.