OBJECTIVES: This research aimed to evaluate the repercussions of specific chest physiotherapy procedures in mean airway resistance and in dynamic compliance in preterm infants in mechanical ventilation. METHODS: Eighteen preterm infants in conventional mechanical ventilation were submitted to one session of chest physiotherapy (manual chest compression during expiration + intermittent aspiration of intratracheal cannula). Mean airway resistance and dynamic compliance measurements were taken prior to, 10, 40 and 70 minutes after intervention using a pneumotachograph with graphic display (Newport Navigator GM-250®), coupled to a flow transducer (Varfley-Bicore®). For analysis of results the infants were divided into 2 groups; less than 5 days (group mechanical ventilation <5) and 5 days or more (group mechanical ventilation >5) on mechanical ventilation. Values were analyzed by Friedman Test, with Dunn's Multiple Comparisons Test (p<0,05 significant). RESULTS: In group mechanical ventilation <5 a significant reduction of mean airway resistance was observed at the 10th minute after intervention (p<0,05). There were no significant alterations in dynamic compliance. The group mechanical ventilation >5 mean airway resistance had a significant reduction at the 10th (p<0,001), 40th (p<0,05) and 70th (p<0,05) minute after intervention. The dynamic compliance improved significantly only at the 10th minute (p<0,05). CONCLUSIONS: The airway clearance techniques used in preterm neonates under conventional mechanical ventilation >5 improved mean airway resistance and dynamic compliance, with best results for the mean airway resistance.
Infant, newborn; Respiratory mechanics; Physical therapy modalities
