Artificial ventilation in children during anaesthesia using a tidal volume ventilator

Area of Science:

• Pediatric Anesthesiology
• Respiratory Physiology
• Mechanical Ventilation

Background:

• Establishing optimal artificial pulmonary ventilation parameters is crucial for pediatric surgical patients.
• Understanding the relationship between ventilation settings, patient weight, and respiratory mechanics is essential for safe anesthesia.

Purpose of the Study:

• To define standards for artificial pulmonary ventilation in children undergoing abdominal surgery.
• To investigate the relationship between tidal volume, body weight, and ventilatory frequency.
• To assess changes in total respiratory compliance during surgery.

Main Methods:

• Studied 16 children with healthy lungs (2.6-22.6 kg) undergoing abdominal surgery.
• Utilized a tidal volume ventilator and balanced anesthesia.
• Analyzed data on tidal volume, body weight, ventilatory frequency, and total compliance.

Main Results:

• At 20 cycles/min, tidal volume showed a direct proportionality with body weight (VTpat = 12.3 * kg b.w. - 2.1, mean 12.1 ml/kg).
• At 15 cycles/min, tidal volume linearly correlated with body weight (VTpat = 14.6 * kg b.w. + 16, mean 15.9 ml/kg).
• Total compliance decreased during surgery, showing a rectilinear relationship with body weight (CTOT = 11.2 * kg b.w. - 12.5, mean 9.7 ml/kPa/kg at 20 cycles/min).
• Endotracheal peak pressure remained relatively constant, potentially due to compensatory increases in lung volumes in older children.

Conclusions:

• Ventilatory standards based on body weight are proposed for pediatric patients.
• Tidal volume and compliance are predictable based on body weight during mechanical ventilation.
• Further research is needed to fully understand the mechanisms behind constant peak airway pressures.