ABSTRACT
The objective of this study was to assess the participation of thoracoabdominal muscles in breathing and its relationship with clinical risk factors in preterm newborns (PTNBs). This is a multicenter, cross-sectional study conducted in two neonatal intermediate care units with PTNBs between 26 and 35 weeks of age, hemodynamically stable, who used oxygen or ventilatory support during hospital stay. The lateral movements of the thorax were filmed for 2 minutes and the videos were quantitatively evaluated by a researcher blinded to sample data using the MATLAB Software for assessing thoracoabdominal participation patterns. Data for the maximum, minimum and mean values of the participation of the thorax and abdomen were expressed graphically in cm2. The Pearson correlation coefficient was used to assess the correlation between neonatal variables and mobility. We evaluated 2,080 frames of 26 newborns with an average gestational age of 31 weeks ±2.34. The greater the age and weight, the greater the participation of the thorax in breathing (r=0.55, p=0.001); and the longer the hospital stay, the lower the thoracic participation (r=-0.40, p=0.04). The participation of the abdomen increases according to the increase in the number of days of oxygen use (r=0.33, p=0.001) and decreases with higher age and weight (r=-0.41, p=0.001). The thoracoabdominal participation pattern is directly related to gestational age and weight. Prolonged use of oxygen and the length of hospital stay adversely affect the respiratory pattern, since increasing abdominal participation in respiratory biomechanics may increase energy expenditure.
Keywords:
Infant, Premature; Respiratory Mechanics; Thoracic Wall; Abdominal Wall; Photogrammetry