Objective To observe different ways of implementing the techniques of aspiration of preterm infants and verify factors associated with changes in oxygen saturation and contamination of equipment.

Methods An observational, prospective, descriptive study. The aspirations of the endotracheal tube in infants with birth weights between 500 and 1500 g were observed during two procedures; morning and evening.

Results We evaluated 32 infants with a mean weight of 942 g and a mean gestational age of 28 weeks (64 aspiration procedures). During aspiration 61% of children had hypoxemia. The saturation drops were more related to the aspiration held by a single professional, also when they were made more than three disconnections of the fan and when disconnections occurred beyond fifteen seconds. The pre – oxygenation did not decrease significantly during the procedure hypoxia and preterm – oxygen showed hyperoxia from third minute of recovery. The aspiration held by two professionals joined the adequate pre – oxygenation, decreased number and duration of disconnections ventilation, and less contamination of materials. The use of saline during suctioning in less than 1 ml volume was associated with significant decreases saturation.

Conclusions The aspiration of the endotracheal tube can lead to hypoxemia. To minimise episodes is important that it be performed by two professionals that meet the care disconnecting the system less than 3 times and use less than 15 seconds. Also pre-oxygenation should be done with caution and the use of less than 1 ml volume of saline solution leads to negative consequences for the patient.