The acute care of traumatic brain injury

Pumpless extracorporeal lung assist (pECLA) in patients with acute respiratory distress syndrome and severe brain injury

BACKGROUND

A retrospective analysis was performed to estimate the practicability of a pumpless extracorporeal lung assist system (pECLA) in trauma patients suffering from severe brain injury and the acute respiratory distress syndrome (ARDS).

METHODS

Five patients with acute severe brain injury and ARDS, ventilated in a lung protective mode, were connected to pECLA to avoid the detrimental effects of hypercapnia on intracranial pressure (ICP) and cerebral outcome. With pECLA hypercapnia was eliminated in all patients while the minute volume of artificial ventilation could be reduced. Subsequently, ICP was reduced, systemic hemodynamics and cerebral perfusion pressure remained stable. One patient died due to multi-organ failure as a consequence of multi-trauma. The remaining patients survived showing a good neurologic function.

CONCLUSIONS

pECLA is a promising alternative compared with conventional pump-driven systems for patients with ARDS and brain injury, since the pECLA system has minor restrictions, limitations and side effects.

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.