Fluid Challenge During Anesthesia: A Systematic Review and Meta-analysis

Area of Science:

• Anesthesiology and Critical Care Medicine
• Hemodynamics and Fluid Management

Background:

• Assessing patient volemic status is crucial for anesthesiologists during surgery.
• Fluid challenge (FC) and dynamic indexes during mechanical ventilation are common assessment methods.
• FC is used for Goal-Directed Therapy (GDT) or to manage hemodynamic instability (non-GDT).

Purpose of the Study:

• To compare fluid challenge components in GDT versus non-GDT studies.
• To assess the effectiveness of pulse pressure variation (PPV) and stroke volume variation (SVV) in predicting fluid responsiveness through meta-analysis.

Main Methods:

• Systematic review and meta-analysis of 68 studies (35 non-GDT, 33 GDT) involving 5017 patients.
• Analysis of FC components: fluid type, volume, and infusion time.
• Meta-analysis of PPV and SVV for predicting fluid responsiveness.

Main Results:

• Colloids, particularly 6% hydroxyethyl starch (HES), were the predominant fluid used in both GDT and non-GDT studies.
• Non-GDT studies used a median FC volume of 500 mL, lacking standardization in infusion time and targets.
• GDT studies typically used 250 mL of colloids over 10 minutes, targeting a >10% stroke volume increase, with safety limits in 60.6% of studies.
• Pooled area under the curve for PPV was 0.86 and for SVV was 0.87.
• PPV thresholds averaged 10.5% (sensitivity 0.80, specificity 0.83), and SVV thresholds averaged 11.3% (sensitivity 0.82, specificity 0.77).

Conclusions:

• Fluid challenge components (colloids, volume, infusion time) show standardization in surgical settings.
• Despite standardization, the pooled sensitivity and specificity of PPV and SVV in predicting fluid responsiveness are limited.