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Question 18#

Monitoring local brain tissue oxygen tension (PbtO₂) in patients with severe TBI:

A. Has shown that normal ICP and CPP generally precludes the presence of brain tissue ischemia
B. Has been shown to lower mortality when compared with ICP monitoring alone
C. Has not been adopted into routine clinical practice due to additional adverse effects from additional, potentially unnecessary, interventions
D. Has been shown to increase stroke rate as a complication of catheter placement

Correct Answer is B

Comment:

While the standard of care for patients with severe TBI includes ICP and CPP monitoring, this strategy does not always prevent secondary brain injury. Growing evidence suggests that monitoring local brain tissue oxygen tension (PbtO₂) may be a useful adjunct to ICP monitoring in these patients. Normal values for PbtO₂ are 20 to 40 mm Hg, and critical levels are 8 to 10 mm Hg. A recent clinical study sought to determine whether the addition of a PbtO₂ monitor to guide therapy in severe TBI was associated with improved patient outcomes. Mortality was significantly lower in the patients who had therapy guided by PbtO₂ monitoring in addition to ICP and CPP (25%; P < 0.05). The benefits of PbtO₂ monitoring may include the early detection of brain tissue ischemia despite normal ICP and CPP. In addition, PbtO₂-guided management may reduce potential adverse effects associated with therapies to maintain ICP and CPP.