Does positioning affect tracheal aspiration of gastric content in ventilated infants?

Gastroesophageal reflux and aspiration can occur in premature infants who are supported with mechanical ventilation. The relation between physical positioning and gastric aspiration in ventilated infants has not been studied. Pepsin measured in tracheal aspirate (TA) emerged as a specific marker for aspiration. The objective of our study was to assess pepsin in TA of ventilated infants at 2 different positions: supine and right lateral.

We conducted a randomized controlled trial on premature infants who were enterally fed and supported with mechanical ventilation. Patients were randomized into intervention and control groups. In the intervention group, infants were placed supine for 6 hours before a sample of TA was obtained. A second sample was collected 6 hours later while lying in the right lateral position. In the control group, the 2 samples of TA were obtained while infants remained in the supine position during the entire study time. Pepsin in TA was measured while blinded to the group assignment.

A total of 34 patients were enrolled and randomized to intervention (n = 17) and control (n = 17) groups. Gestational age was 32.7 ± 2.7 weeks, and birth weight was 1617 ± 526 g; both groups had similar demographic and clinical characteristics. Pepsin concentration did not differ between groups at baseline. In the intervention group, pepsin concentration significantly declined from 13 ng/mL (interquartile range [IQR] 11.9-38.7) to 10 ng/mL (IQR 7-12; P < 0.001), whereas it did not change in the control group (P = 0.42).

The right lateral positioning is associated with decreased TA pepsin. The implications of the present study on hospital practice and clinical outcomes need further investigations.