Ventilator Circuits as a Potential Source of Airway Microplastics in Mechanically Ventilated Neonates

Abstract Background Mechanically ventilated neonates experience sustained contact with polymer-containing respiratory devices, yet paired evidence linking used ventilator circuits with airway microplastic findings is scarce. Methods This prospective single-center paired observational study included 20 neonates receiving invasive ventilation. Airway secretion was retained only during clinically indicated suction, and the corresponding used inspiratory-limb patient-end inner surface was rinsed ex vivo after circuit exchange or extubation. Confocal micro-Raman spectroscopy was used for particle identification. A complementary 72-h bench experiment compared PE particle counts in patient-end gas output with system blanks and in eluates from unused and post-run circuits. Results Microplastics were detected in 15 of 20 airway secretion samples (75.0%) and 17 of 20 circuit rinse samples (85.0%). Airway and circuit particle counts increased across ventilation-duration groups (Kruskal-Wallis P = 0.021 and P = 0.003, respectively), and paired circuit and airway counts were correlated (Spearman rho = 0.820, P < 0.001). In the bench experiment, patient-end gas output contained more PE particles than system blanks (median 12.0 [IQR 8.0–17.0] versus 1.0 [1.0-1.8] particles/m3; exact P = 0.0004). Post-run circuit eluates also exceeded unused circuit eluates (11.0 [9.0–13.0] versus 2.0 [2.0–3.0] particles/10 mL; exact P = 0.000041). Conclusions Paired clinical findings and controlled bench results support ventilator-circuit-associated airway microplastic exposure. The data show that PE particles can be released from circuits under bench conditions and that circuit use is associated with microplastic burden in airway secretion samples. Larger studies with unused suction-device controls and repeated clinical sampling are needed to establish in vivo transfer and clinical relevance.