Ultrasonographic assessment of optic nerve sheath diameter in children receiving epidural analgesia
Lumbar epidural patient-controlled analgesia (PCA) is commonly used for postoperative analgesia in children with cerebral palsy undergoing orthopedic surgery, however is associated with potentially serious side effects, such as increased intracranial cerebral pressure (ICP). Optic nerve sheath diameter (ONSD) correlates with degree of ICP. We compared two methods of epidural analgesia in pediatric orthopedic surgeries, with the primary aim of assessing the effect of lumbar epidural block on ICP.
Material and methods
This randomized controlled trial was approved by the institutional review board of Severance Hospital, Korea (No. 4-2017-0341). After obtaining written informed consent from the parents or legal guardians, we enrolled 27 children with cerebral palsy (4-14 years old) scheduled for orthopedic surgery of the lower extremities and lumbar epidural patient-controlled analgesia (PCA). Children were randomly assigned to receive epidural bolus (bolus group; 0.15% ropivacaine 0.3ml/kg bolus, n=13) or continuous epidural infusion (infusion group; 0.15% ropivacaine 0.3ml/kg/hr, n=14). Measurement of ONSD was performed before (T0), immediately after (T1), and 10 min (T2) and 60 min (T3) after lumbar epidural block.
The two groups exhibited significant differences in ONSD according to time (P Group x Time = 0.001). The bolus group exhibited significantly greater changes in ONSD from T0 to T2 than the infusion group. However, ONSD at T3 were comparable between the two groups.
In pediatric patients with cerebral palsy, both epidural bolus and infusion groups showed significant increase in ICP and there was no difference in ICP increase between the two groups.