Effect of Positive End-Expiratory Pressure on Optic Nerve Sheath Diameter in Pediatric Patients with Traumatic Brain Injury.

BACKGROUND: The peak incidence of traumatic brain injury (TBI) has been reported in children and young adults. Intracranial pressure (ICP) as an important component can be measured with invasive technique, whereas noninvasive measurement of optic nerve sheath diameter (ONSD) is increasingly becoming popular. Positive end-expiratory pressure (PEEP) has been found to affect ICP. We aimed to compare the effect of different values of PEEP on ONSD and to obtain the correlation with ICP measurement.

SETTING AND DESIGN: Neurointensive Care Unit, Trauma Center, AIIMS, New Delhi.

MATERIALS AND METHODS: Pediatric patients with TBI, of either gender, between 1 and 18 years of age in whom ICP was measured using intraparenchymal Codman catheter admitted in neurointensive care unit were enrolled. For this crossover study, the sequence of PEEP (0 or 3 or 5 cm H2 O) was randomized and ONSD was measured. The mean of three ONSD values was taken as final value.

STATISTICAL METHOD: The ONSD, ICP, peak airway pressure, and hemodynamic parameters at various stages were compared using two-way repeated measures analysis of variance with Bonferroni correction. A P value of <0.05 was considered to be significant.

RESULTS: Ten patients (seven males, three females) participated in the study. There was no significant increase in ONSD values when PEEP was increased from 0 to 3 cm H2 O. However, increase in PEEP values from 3 to 5 cm H2 O showed significantly increased ONSD values.

CONCLUSION: PEEP up to 3 cm H2 O can be safely applied in pediatric patients following TBI. Further increment of PEEP might accentuate the ICP values.