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US study of gliding in nondependent lung regions: the dark side of the moon


A protective ventilatory strategy should prevent VILI, but in patients with larger nonaerated areas hyperinflation may occur during tidal ventilation even during a protective ventilatory strategy [1]. The gliding sign is used as a marker of pneumothorax and, in a study [2], to quantify preoperatively the degree of pleural adhesion in thoracic surgery patients. In our study we measured the variations of gliding (G) and static compliance (Cstat) according to incremental/ decremental variations of PEEP in patients with hypoxic respiratory failure.


Ten patients with hypoxic respiratory failure (P/F <300) were ventilated in VcV (Vt of 7 ml/kg, FiO2 100%, RR 10/minute); keeping Vt constant, PEEP was gradually increased from ZEEP to 22 cmH2O, unless there was occurrence of hypotension or SpO2 <90% or Pplat >45 cmH2O or G no more visible, and then similarly reduced from 22 cmH2O to ZEEP. The gliding was assessed at six points of intercostal spaces bilaterally and the movement of a hyperechoic point of pleura or a b-line was observed during tidal ventilation. For each step, the excursion of G during the inspiratory phase was measured and compared with the Cstat values. Statistical analysis was performed with the Pearson correlation coefficient (PCC).


All patients completed the study without adverse events. In all patients we observed a reduction of G and Cstat at the increase of PEEP and specularly an increase of G and Cstat during the reduction of PEEP (Figure 1). In five patients at the lower levels of PEEP (from 0 to 10) an increase of Cstat and G was observed. For all patients the PCC of Cstat and G and was >0.5 (P < 0.03), ranging from 0.537 (P = 0.017) to 0.964 (P < 0.0001).

Figure 1
figure 1

PCC between mean G (cm) and mean Cstat at different PEEP, in axis Pplat.


The variations of G at different levels of PEEP are consensual with those of Cstat. The study of G during tidal ventilation could help to identify hyperinflation in nondependent lung regions and to optimize lung-protective ventilatory strategies.


  1. Terragni PP, et al.: Am J Respir Crit Care Med. 2007, 175: 160-166. 10.1164/rccm.200607-915OC

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  2. Masato S, et al.: Ann Thorac Surg. 2005, 80: 439-442. 10.1016/j.athoracsur.2005.03.021

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De Blasio, E., Venditto, M., Federico, A. et al. US study of gliding in nondependent lung regions: the dark side of the moon. Crit Care 18 (Suppl 1), P274 (2014).

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