Correlation between optic nerve sheath diameter and extracorporeal life support time.

Introduction: The objective of the study was to analyse the correlation between extracorporeal life support (ECLS) and aortic cross-clamp times and optic nerve sheath diameter (ONSD).

Patients And Methods: Study in a cohort of patients aged 0-15 years that underwent ECLS for cardiac surgery after obtention of signed informed consent. We calculated a sample size of 23 participants. First, we obtained 3 vertical and 3 horizontal measurements of the ONSD for each eye and calculated the mean of both eyes for each measurement to be used in the analysis. The measurements were made at admission and at 6 and 24 h post surgery. We retrieved the ECLS time and the aortic cross-clamp time were from the operative report.

Results: We analysed data for 23 participants, 52.2% female, with a median age of 14 months. The median ECLS time was 60 min; the median aortic cross-clamp time was 32 min. The median baseline ONSD was 3.1 mm. ONSD values had increased a median of 0.015 mm at 6 h post surgery (P = .03). We found a positive correlation between ECLS time and ONSD values (r = 0.476, P < 0,05). The ONSD values returned to baseline by 24 h post surgery. None of the patients developed signs or symptoms of increased intracranial pressure.

Conclusion: Our study found a correlation between ECLS time and ONSD at 24 h post surgery. We found variations in the ONSD even in patients without signs or symptoms of increased ICP. Further research is required to identify the factors related to these variations.