Monitoring cerebrovascular reactivity in pediatric traumatic brain injury: comparison of three methods

Autores da FMUP

• Maria Celeste Pinheiro Dias Ferreira

  Autor

Participantes de fora da FMUP

• Abecasis, F
• Zakrzewska, A
• Oliveira, V
• Czosnyka, M

Unidades de investigação

• Medicina

Abstract

Purpose To study three different methods of monitoring cerebral autoregulation in children with severe traumatic brain injury. Methods Prospective cohort study of all children admitted to the pediatric intensive care unit at a university-affiliated hospital with severe TBI over a 4-year period to study three different methods of monitoring cerebral autoregulation: pressure-reactivity index (PRx), transcranial Doppler derived mean flow velocity index (Mx), and near-infrared spectroscopy derived cerebral oximetry index (COx). Results Twelve patients were included in the study, aged 5 months to 17 years old. An empirical regression analyzing dependence of PRx on cerebral perfusion pressure (CPP) displayed the classic U-shaped distribution, with low PRx values (< 0.3) reflecting intact auto-regulation, within the CPP range of 50-100 mmHg. The optimal CPP was 75-80 mmHg for PRx and COx. The correlation coefficients between the three indices were as follows: PRx vs Mx, r = 0.56; p < 0.0001; PRx vs COx, r = 0.16; p < 0.0001; and COx vs Mx, r = 0.15; p = 0.022. The mean PRx with a cutoff value of 0.3 predicted correctly long-term outcome (p = 0.015). Conclusions PRx seems to be the most robust index to access cerebrovascular reactivity in children with TBI and has promising prognostic value. Optimal CPP calculation is feasible with PRx and COx.

Keywords

• Traumatic brain injury; Pediatrics; Cerebrovascular circulation; Intracranial pressure; Cerebral perfusion pressure