Does a two-minute mini-fluid challenge predict fluid responsiveness in pediatric patients under general anesthesia?

Area of Science:

• Pediatric critical care medicine
• Anesthesiology
• Cardiovascular physiology

Background:

• Limited evidence exists for pediatric predictive markers of fluid responsiveness compared to adults.
• Fluid management is crucial for minimizing morbidity associated with hypovolemia and hypervolemia.
• The fluid challenge titration strategy is of significant clinical interest.

Purpose of the Study:

• To evaluate the predictive capability of a 3 mL/kg mini-fluid challenge over 2 minutes for fluid responsiveness in mechanically ventilated children.
• To assess the utility of changes in left ventricular outflow tract velocity time integral (VTI) as a predictor.

Main Methods:

• A prospective study included children undergoing surgery under general anesthesia.
• Patients received a 15 mL/kg crystalloid fluid challenge in two steps: 3 mL/kg over 2 minutes, followed by 12 mL/kg over 8 minutes.
• Fluid responsiveness was determined by a ≥10% increase in cardiac output, estimated via VTI changes measured by transthoracic ultrasound.

Main Results:

• Out of 55 patients, 43 were identified as fluid responders.
• The increase in VTI after the mini-fluid challenge (ΔVTI_miniFC) demonstrated an area under the ROC curve of 0.77 (P = .004).
• A threshold of 8% for ΔVTI_miniFC yielded 53% sensitivity and 77% specificity for predicting fluid responsiveness.

Conclusions:

• The ΔVTI_miniFC weakly predicted the response to a larger fluid challenge in anesthetized, mechanically ventilated children.
• Further research is needed to identify reliable predictors of fluid responsiveness in pediatric populations.