Tidal Volume Challenge to Predict Fluid Responsiveness in Liver Transplant Recipients Ventilated Using Low Tidal...

Area of Science:

• Critical Care Medicine
• Anesthesiology
• Transplant Surgery

Background:

• Low tidal volume ventilation limits dynamic indices for fluid responsiveness assessment.
• Liver transplant recipients often require careful fluid management.
• Predicting fluid responsiveness is crucial for optimizing hemodynamics in this population.

Purpose of the Study:

• To evaluate the efficacy of a tidal volume challenge in predicting fluid responsiveness.
• To assess changes in pulse pressure variation (PPV) and stroke volume variation (SVV) after a tidal volume challenge.
• To determine the predictive value of these dynamic indices in liver transplant recipients under low tidal volume ventilation.

Main Methods:

• Prospective intervention study in liver transplant recipients.
• Hypotensive patients on low tidal volume ventilation received a transient tidal volume challenge (6 to 8 mL/kg PBW).
• Changes in PPV and SVV were measured before fluid administration; fluid responsiveness was defined as >10% increase in stroke volume index.

Main Results:

• 12 of 28 patients (42.9%) were fluid responders.
• Mean PPV and SVV changes were significantly higher in responders (2.00±0.60, 2.33±0.77) vs. non-responders (1.06±0.44, 0.87±0.62).
• Area under the curve for PPV and SVV changes was 0.87 and 0.91, respectively, with a cut-off of 1.5 yielding 83.3% sensitivity and 87.5% specificity.

Conclusions:

• Changes in PPV and SVV following a tidal volume challenge are reliable predictors of fluid responsiveness.
• This method is effective in liver transplant recipients managed with lung protective ventilation strategies.
• The tidal volume challenge offers a practical approach to guide fluid management in this specific patient group.