The Effect of Fluid Challenge Test on Optic Nerve Sheath Diameter

Area of Science:

• Critical Care Medicine
• Nephrology
• Medical Imaging

Background:

• Fluid therapy is crucial in intensive care units (ICUs) but requires careful monitoring to avoid complications.
• Optic nerve sheath diameter (ONSD) measured via ultrasonography is a non-invasive method to assess intracranial pressure.
• Fluid challenge tests assess fluid responsiveness, a key parameter in hemodynamic management.

Purpose of the Study:

• To investigate the impact of a standardized fluid challenge test on ONSD.
• To determine if changes in ONSD correlate with fluid responsiveness in ICU patients.

Main Methods:

• A quasi-experimental study involving 60 ICU patients.
• A fluid challenge involved a 500 mL crystalloid infusion over 10 minutes.
• ONSD and hemodynamic variables, including stroke volume, were measured using ultrasonography at baseline, immediately after, and 30 minutes post-challenge.

Main Results:

• ONSD showed a statistically significant increase immediately after the fluid challenge (T1) compared to baseline (T0) (p=0.011).
• At 30 minutes post-challenge (T2), ONSD returned to baseline levels (p=0.662).
• Stroke volume increased significantly post-fluid challenge, but no significant relationship was found between ONSD changes and fluid responsiveness (p=0.621).

Conclusions:

• The fluid challenge test transiently increases ONSD in ICU patients.
• This ONSD increase suggests a potential, temporary rise in intracranial pressure.
• The study found no correlation between ONSD changes and fluid responsiveness.