RESUMO
In this protocol, two deep breathing patterns were shown to 15 participants to determine an easy yet effective method of breathing exercise for future application in a clinical setting. The women in their twenties were seated comfortably in a chair with back support. They were fitted with an airtight mask connected to a gas analyzer. Three electrodes were placed on the chest connected to a wireless transmitter for relaying to the electrocardiograph. They executed a 5 min rest phase, followed by 5 min of deep breathing with a natural breathing pattern, terminating with a 5 min rest phase. This was followed by a 10 min intermission before commencing the second instruction phase of substituting the natural breathing pattern with the diaphragmatic breathing pattern. Simultaneously, the following took place: a) continuous collection, measurement and analysis of the expired gas to assess the ventilatory parameters on a breath-by-breath basis; b) measurement of the heart rate by an electrocardiograph; and c) videotaping of the participant's thoracoabdominal movement from a lateral aspect. From the video capture, the investigators carried out visual observation of the fast-forward motion-images followed by classification of the breathing patterns, confirming that the participants had carried out the method of deep breathing as instructed. The amount of oxygen uptake revealed that, during deep breathing, the work of breathing decreased. The results from the expired minute ventilation, respiration rate and tidal volume confirmed increased ventilatory efficiency for deep breathing with the natural breathing pattern compared to that with the diaphragmatic breathing pattern. This protocol suggests a suitable method of instruction for assessing deep breathing exercises on the basis of oxygen consumption, ventilatory parameters, and chest wall excursion.
