Non-invasive assessment of cerebral perfusion pressure in brain injured patients with moderate intracranial hypertension.

BACKGROUND: A non-invasive estimation of cerebral perfusion pressure (CPP) using transcranial Doppler sonography was assessed in brain-injured patients by comparing conventional measurements of CPP (difference between mean arterial pressure and intracranial pressure) (CPPm) with the difference between AP(mean) and the critical closing pressure of the cerebral circulation (CPPe). METHODS: Twenty adults with bilateral and diffuse brain injuries were included in the study. CPPe was estimated using a formula combining the phasic values of flow velocities and arterial pressure. In group A (n=10) the comparison was repeatedly performed under stable conditions. In group B (n=10) the comparison was performed during a CO(2) reactivity test. Covariance analysis was used to assess the relationships. RESULTS: In group A, CPPe and CPPm were correlated (slope, 0.76; intercept, +10.9; 95% CI, -3.5 to +25.4). During the increase in intracranial pressure (group B) (+1.9 (sd 1.5) mm Hg per mm Hg of Pe'(co(2))) the relationship persisted (slope, 0.55; intercept, +32.6; 95% CI, +16.3 to +48.9) but the discrepancy between the two variables increased as reflected by the increase in bias and variability. CONCLUSION: Non-invasive estimation of CPP can be used for brain monitoring of head-injured patients, but the accuracy of the method may depend on the level of intracranial hypertension.

[Medical prehospital rescue in head injury]. / Prise en charge préhospitalière des traumatisés crâniens.

OBJECTIVE: To evaluate the effectiveness of prehospital medical care in head-injured patients. PATIENTS AND METHODS: All head-injured patients admitted in Bicêtre hospital from 1995 to 1999 were retrospectively studied. Glasgow Coma Scale (GCS) score, mean arterial pressure (MAP) and SpO(2) measured on the field were compared to GCS, MAP and SpO(2) on arrival in the hospital. All treatments given during transport and first data recorded in the hospital were noted. Each parameter was compared to outcome at 6 months. Then, significant parameters were compared with a multivariate analysis. RESULTS: Three hundred and four patients were included, 80% had a GCS