Evaluation of Intra-Cranial Pressure Changes by Measuring the Optic Nerve Sheath Diameter During the Lung Recruitment Maneuver in Patients with Acute Respiratory Distress Syndrome: A Prospective Study

Abstract

Background: The lung recruitment maneuver (LRM) applied in acute respiratory distress syndrome (ARDS) may increase the intra-cranial pressure (ICP). Aims: This study evaluated the effect of LRM on intra-cranial pressure changes in patients with ARDS by measuring the optic nerve sheath diameter (ONSD). Patients and Methods: LRM was applied to patients undergoing follow-up for ARDS, with a positive pressure of 30 cmH(2)O for 30 s. ONSD on ultra-sonography, dynamic lung compliance (C-dyn), oxygen saturation (S-pO2), and hemodynamic parameters were measured before (T0), immediately after (T1), and 10 min after (T2) LRM. The primary endpoint was the effect of LRM on ONSD changes. The secondary endpoints included the effect of LRM on C-dyn, SpO(2) change, and relationship between C(dyn )and ONSD changes. Results: The study included 60 patients. ONSD was higher at T1 than at T0 (median [interquartile range]: 5.13 [0.4] vs. 5.3 [0.3] mm, P < 0.001) but was similar at T0 and T2 (5.13 [0.4] vs. 5.09 [0.37] mm, P = 0.36). C(dyn )and S-pO2 were significantly higher at T1 and T2 than at T0 (C-dyn: 22.3 [5.8] vs. 23.7 [7.5] vs. 19.4 [6.6] mL/cmH(2)O, P < 0.001; S-pO2: 90[2] vs. 92[4] vs. 88[4] %, P = 0.013). A significant correlation existed between C(dyn )and ONSD changes, which increased at T2 compared to T0 (P < 0.001). Conclusion: LRM applied in ARDS causes a short-term increase in ONSD. However, C-dyn increases 10 min after LRM and causes ONSD, thereby leading to a decrease in ICP.