Abstract
In vitro experiments have suggested that respiratory oscillations (R waves) in cerebral blood flow velocity are reduced as soon as the intracranial pressure–volume reserve is exhausted. Could R waves hence, provide indication for increasing ICP after traumatic brain injury (TBI)? On days 1 to 4 after TBI, 22 sedated and ventilated patients were monitored for intracranial pressure (ICP) in brain parenchyma, Doppler flow velocity (FV) in the middle cerebral arteries (MCA), and arterial blood pressure (ABP). The analysis included the transfer function gains of R waves (respiratory rate of 9–20 cpm) between ABP and FV (GainFv) as well as between ABP and ICP (GainICP). Also, the index of the intracranial pressure–volume reserve (RAP) was calculated. The rise of ICP (day 1: 14.10 ± 6.22 mmHg; to day 4: 29.69 ± 12.35 mmHg) and increase of RAP (day 1: 0.72 ± 0.22; to day 4: 0.85 ± 0.18) were accompanied by a decrease of GainFv (right MCA; day 1: 1.78 ± 1.0; day 4: 0.84 ± 0.47; left MCA day 1: 1.74 ± 1.10; day 4: 0.86 ± 0.46; p < 0.01) but no significant change in GainICP day 1: 1.50 ± 0.77; day 4: 1.15 ± 0.47; p = 0.07). The transfer of ventilatory oscillations to the intracerebral arteries after TBI appears to be dampened by increasing ICP and exhausted intracranial pressure–volume reserves. Results warrant prospective studies of whether respiratory waves in cerebral blood flow velocity may anticipate intracranial hypertension non-invasively.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.