Clinical Report: Impact of Injection Velocity on Optic Nerve Sheath Diameter

Overview

This study investigates the effect of injection speed on optic nerve sheath diameter (ONSD) changes during caudal block in pediatric patients.

Background

Caudal block is a common anesthetic technique in pediatric surgery, but its impact on intracranial pressure, as indicated by ONSD, is not fully understood. This study addresses a gap in knowledge regarding the standardization of injection techniques.

Data Highlights

Key Findings

• High-speed injection resulted in a significantly higher ONSD at T2 compared to low-speed injection (P = 0.027).
• Low-speed injection resulted in a significantly higher ONSD at T3 compared to high-speed injection (P = 0.010).
• Both groups showed significant increases in ONSD from baseline (T1) onward (P < 0.05).
• No significant differences in mean arterial pressure, heart rate, or end-tidal carbon dioxide were observed (P > 0.05).
• Both injection speeds were well tolerated with no adverse events reported.

Clinical Implications

The findings suggest that slower injection speeds may be preferable for routine practice to achieve a more gradual rise in ONSD. Clinicians should consider the impact of injection speed on ONSD dynamics when performing caudal blocks in pediatric patients.

Conclusion

This study highlights the importance of injection speed in influencing ONSD changes during caudal block in children. Further research may be warranted to establish standardized practices for injection techniques.

Related Resources & Content

1. Frontiers in Pediatrics, 2026 -- Ultrasonographic Optic Nerve Sheath Diameter as a Non-Invasive Marker of Intracranial Hypertension in Pediatric Patients: A Pilot Study
2. Intensive Care Medicine, 2009 -- Cerebral Vasospasm in Pediatric Patients Following Traumatic Brain Injury
3. Impact of Varying Positive End Expiratory Pressure on Optic Nerve Sheath Diameter in Supratentorial Craniotomy Patients with or without Midline Shift
4. Frontiers in Surgery, 2026 -- Assessment of Optic Nerve Alterations via Ocular Ultrasonography During Epiduroscopy: A Comprehensive Review
5. Caudal block | European Society for Paediatric Anaesthesiology
6. Frontiers | Measuring optic nerve sheath diameter in children: a simple ultrasound protocol for ICP assessment
7. Evaluating the effect of caudal epidural block on optic nerve sheath diameter in pediatric patients: randomized controlled study | BMC Anesthesiology
8. Caudal block | European Society for Paediatric Anaesthesiology
9. Frontiers | Measuring optic nerve sheath diameter in children: a simple ultrasound protocol for ICP assessment
10. Evaluating the effect of caudal epidural block on optic nerve sheath diameter in pediatric patients: randomized controlled study | BMC Anesthesiology | Springer Nature Link