Is Pulse Co-Oximetry a Reliable Alternative to Invasive Hemoglobin Measurement in Pediatric Neurosurgical Procedures?

Area of Science:

• Anesthesiology
• Neurosurgery
• Pediatric Critical Care

Background:

• Pediatric neurosurgery involves significant blood loss and hemodynamic shifts, requiring accurate hemoglobin monitoring.
• Continuous non-invasive hemoglobin (SpHb) monitoring offers trending but its accuracy in high-risk pediatric populations is debated.

Purpose of the Study:

• Evaluate the diagnostic accuracy and clinical utility of SpHb compared to invasive arterial blood gas (ABG) analysis in pediatric neurosurgery patients.
• Assess SpHb performance under various physiological conditions, including hypotension and metabolic acidosis.

Main Methods:

• Prospective, observational study of 60 pediatric patients undergoing cranial and spinal surgeries.
• Continuous SpHb monitoring compared with intermittent ABG-Hb values.
• Statistical analysis included Bland-Altman agreement, Pearson's correlation, and Error Grid Analysis, with subgroup analyses for Perfusion Index, hypotension, and acidosis.

Main Results:

• SpHb showed moderate correlation (r=0.567) but systematic overestimation (+1.60 g/dL bias) compared to ABG-Hb.
• SpHb had 0% sensitivity for detecting critical anemia (Hb < 8.0 g/dL).
• Device accuracy decreased with severe metabolic acidosis and intraoperative hypotension, impacting hemodynamic autoregulation.

Conclusions:

• SpHb provides fair hemoglobin trending but is limited by overestimation and poor sensitivity for critical anemia.
• Accuracy is compromised during severe acidosis and hemodynamic instability.
• SpHb should be a complementary trend monitor, not a sole transfusion trigger; invasive validation is crucial for intraoperative decisions.