The effect of anesthesia depth on the oculocardiac reflex in strabismus surgery

Area of Science:

• Anesthesiology
• Pediatric Surgery
• Ophthalmology

Background:

• The oculocardiac reflex (OCR) is a common concern during strabismus surgery in children.
• Monitoring anesthetic depth is crucial for managing intraoperative events.
• The bispectral index (BIS) is a tool used to assess the depth of anesthesia.

Purpose of the Study:

• To investigate the effect of bispectral index (BIS) guided anesthesia depth on inhibiting the oculocardiac reflex (OCR) in pediatric strabismus surgery.
• To determine if a BIS value below 50 offers better protection against OCR compared to values of 50 or above.

Main Methods:

• A randomized study involving pediatric patients (3-16 years) undergoing strabismus surgery.
• Two groups were established: Group 1 with BIS <50 and Group 2 with BIS ≥50.
• Anesthesia was maintained using desflurane in an O2-air mixture, with BIS values titrated during surgery.

Main Results:

• The incidence of OCR was significantly lower in Group 1 (25%) compared to Group 2 (64.3%) (p < 0.05).
• In Group 2, OCR incidence was higher with medial rectus traction (78.9%) than lateral rectus traction (33.3%) (p = 0.035).
• No significant difference in OCR incidence was observed between medial and lateral rectus traction in Group 1 (p = 0.83).

Conclusions:

• Lower BIS values (<50) are associated with a reduced incidence of OCR in pediatric strabismus surgery.
• Deeper anesthesia, as indicated by lower BIS values, provides a protective effect against the oculocardiac reflex.
• Anesthetic depth monitoring using BIS can help prevent OCR during pediatric eye muscle surgery.