The American journal of emergency medicine
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Observational Study
Cerebral oximetry with blood volume index and capnography in intubated and hyperventilated patients.
Hyperventilation-induced hypocapnia leads to cerebral vasoconstriction and hypoperfusion. Intubated patients are often inadvertently hyperventilated during resuscitations, causing theoretical risk for ischemic brain injury. Current emergency department monitoring systems do not detect these changes. The purpose of this study was to determine if cerebral oximetry (rcSo2) with blood volume index (CBVI) would detect hypocapnia-induced cerebral tissue hypoxia and hypoperfusion. ⋯ This preliminary study has demonstrated the ability of rcSo2 with CBVI to noninvasively detect the real-time effects of excessive hyperventilation producing ETco2 < 30 mmHg on cerebral physiology in an emergency department. We have demonstrated in patients with suspected increased intracranial pressure that ETco2 < 30 mmHg causes a significant decrease in cerebral blood flow and regional tissue oxygenation.