Korean J Anesthesiol.  2024 Feb;77(1):115-121. 10.4097/kja.23194.

Comparison of the effects of open and closed aspiration on end-expiratory lung volume in acute respiratory distress syndrome

• Yildirim S
• Saygili SM
• Süneçli O
• Kirakli C

• KMID: 2551488
• DOI: http://doi.org/10.4097/kja.23194

Abstract

Background
Alveoli tend to collapse in patients with acute respiratory distress syndrome (ARDS). Endotracheal aspiration may increase alveolar collapse due to the loss of end-expiratory lung volume (EELV). We aimed to compare the loss of EELV after open and closed suction in patients with ARDS.
Methods
This randomized crossover study included 20 patients receiving invasive mechanical ventilation for ARDS. Open and closed suction were applied in a random order. Lung impedance was measured using electric impedance tomography. The change in end-expiratory lung impedance end of suction and at 1, 10, 20, and 30 min after suction, was used to represent the change in EELV. Arterial blood gas analyses and ventilatory parameters such as the plateau pressure (Pplat), driving pressure (Pdrive), and compliance of the respiratory system (CRS) were also recorded.
Results
Less volume loss was noted after closed suction than after open suction (mean ΔEELI: −2661 ± 1937 vs. −4415 ± 2363; mean difference: −1753; 95% CI [−2662, −844]; P = 0.001). EELI returned to baseline 10 min after closed suction but did not return to baseline even 30 min after open suction. After closed suction, the Pplat and Pdrive decreased while the CRS increased. Conversely, the Pplat and Pdrive increased while the CRS decreased after open suction.
Conclusions
Endotracheal aspiration may result in alveolar collapse due to loss of EELV. Given that closed suction is associated with less volume loss at end-expiration without worsening ventilatory parameters, it should be chosen over open suction in patients with ARDS.

Keyword

Acute respiratory distress syndrome; Critical care; Electric impedance tomography; End-expiratory lung volume; Endotracheal aspiration; Lung imaging.