Effect of Boyle-Davis mouth gag placement on intracranial pressure in children undergoing tonsillectomy: A prospective observational study.
Boyle-Davis mouth gag placement is associated with a small rise in optic nerve sheath diameter
Effect of Boyle-Davis mouth gag placement on intracranial pressure in children undergoing tonsillectomy: A prospective observational study.
Pediatric adenotonsillectomy frequently requires Boyle-Davis mouth gag placement, which may transiently increase intracranial pressure (intracranial pressure).
This study aims to investigate the impact of endotracheal intubation and Boyle-Davis mouth gag placement on optic nerve sheath diameter, eyeball transverse diameter (eyeball transverse diameter), and ratio of optic nerve sheath diameter to eyeball transverse diameter (optic nerve sheath diameter/eyeball transverse diameter) ratio in children.
In this prospective observational study of 120 children (American Society of Anesthesiologists I-II, 2-18 years), bilateral optic nerve sheath diameter and eyeball transverse diameter were measured at post‑induction (T0), post‑intubation (T1), post‑gag placement (T2), and post‑gag removal (T3).
gag placement briefly raised nerve sheath diameter, a sign of higher pressure
Adjusted analyses used linear mixed-effects models with time and random intercept for subject; end-tidal carbon dioxide (EtCO2) and mean arterial pressure (mean arterial pressure) were entered as time-varying covariates.
The overall time effect was significant for both outcomes (P < .01).
Heart rate and mean arterial pressure varied over time (both P < .001), EtCO2 rose early and declined by T3 (P < .001).
Mouth-gag suspension produces a small, transient rise in optic nerve sheath diameter and optic nerve sheath diameter/eyeball transverse diameter that peaks at T2 and recedes after removal.
Findings support prudent positioning and monitoring in at‑risk children.