Intracranial Pressure Pulse Morphology-based Definition of Life-threatening Intracranial Hypertension Episodes

Abstract

Intracranial hypertension (IH) is associated with poor outcome in traumatic brain injury (TBI) patients and must be avoided to prevent secondary brain injury. In clinical practice the most common method of IH detection is the calculation of the mean value of intracranial pressure (ICP) and the therapeutic intervention is usually introduced when the mean exceeds a certain threshold. This threshold, however, is rather individual for each patient than universal for all. Impaired cerebrovascular reactivity and reduced intracranial compliance are associated with raised ICP. This work explores a new definition of life-threatening hypertension (LTH) which accounts for the state of cerebral compliance. In the proposed method, changes in compliance are analysed through identification of likely pathological and/or pathological shapes of ICP pulse waveforms using a neural network. In terms of predictive power for mortality in TBI, detection of both shape clasess of ICP pulse waveforms during raised ICP offers similar results to previously proposed LTH definition accounting for the state of cerebrovascular reactivity (77.8% vs 76.9% accuracy, respectively). On the other hand, the fully pathological shapes of ICP pulses are present during ICP rises almost only in recordings of patients who died: out of 216 analysed patients only 6% of surviving and as many as 42% of deceased patients developed this type of LTH event. The stricter definition of LTH events including only pathological shape of ICP pulses presents the highest accuracy among the analysed approaches for mortality prediction (87.9%).Clinical relevance-Reliable detection of potentially lifethreatening episodes of ICP elevation offers the possibility of improving clinical management of TBI by identifying the patients at risk of unfavourable outcome.

A Comprehensive Perspective on Intracranial Pressure Monitoring and Individualized Management in Neurocritical Care: Results of a Survey with Global Experts

“…It is fundamental to consider patient positioning (bed and head angle) and that these CPP values differences vary among individuals. ABP arterial blood pressure, CPP cerebral perfusion pressure and P3) following changes in the volume/pressure relationship [58][59][60]. Inside the bony box of the skull, the continuously moving interaction between arterial blood flow with the brain and ventricles filled with cerebrospinal fluid, determines the formation of P1 (upstroke peak), P2 (tidal wave), which is associated with ICC, and the buffering reserve.…”

Analysis of intracranial pressure pulse waveform in studies on cerebrospinal compliance: a narrative review

“…In contrast to HFC which is calculated in Hz, HHC is expressed in harmonic number. Adapted with permission from Uryga et al (2022). CC BY-NC-ND 4.0. called the higher harmonics centroid (HHC), was proposed to obtain a measure theoretically less dependent on heart rate than HFC (Berdyga et al 1993) (figure 4(d)).…”

“…In contrast to HFC which is calculated in Hz, HHC is expressed in harmonic number. Adapted with permission fromUryga et al (2022). CC BY-NC-ND 4.0.…”

Predicting short-term outcomes in brain-Injured patients: A comprehensive approach with transcranial Doppler and intracranial compliance assessment

“…Besides primary injuries following kinetic forces in head incidents or spontaneous intracranial bleedings, further damage may occur because of the in ammatory and immune responses in the subsequent early period after an acute brain injury (ABI) 3,4 . All this combination of phenomena contribute to impairment in cerebrovascular properties, raising risks for the development of intracranial hypertension (IH), a life-threatening condition for the neurocritical patient [5][6][7] .…”