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Marker Holman posted an update 6 months, 4 weeks ago
Monitoring of cerebral autoregulation (CA) in patients with a traumatic brain injury (TBI) can provide an individual ‘optimal’ cerebral perfusion pressure (CPP) target (CPPopt) at which CA is best preserved. This potentially offers an individualized precision medicine approach. #link# Retrospective data suggest that deviation of CPP from CPPopt is associated with poor outcomes. We are prospectively assessing the feasibility and safety of this approach in the COGiTATE study. Its primary objective is to demonstrate the feasibility of individualizing CPP at CPPopt in TBI patients. The secondary objectives are to investigate the safety and physiological effects of this strategy.
The COGiTATEstudy has included patients in four Europeanhospitals in Cambridge, Leuven, Nijmegen, and Maastricht (coordinating centre). Patients with severe TBI requiring intracranial pressure (ICP)-directed therapy are allocated into one of two groups. In the intervention group, CPPopt is calculated using a published (modified) algorithm. In the control group, the CPP target recommended in the Brain Trauma Foundation guidelines (CPP60-70mmHg) is used.
Patient recruitment started in February 2018 and will continue until 60 patients have been studied. Fifty-one patients (85% of the intended total) have been recruited in October 2019. The first results are expectedearly 2021.
This prospective evaluation of the feasibility, safety and physiological implications of autoregulation-guided CPPmanagement is providing evidence that will be useful in the design of a future phase III studyin severe TBI patients.
This prospective evaluation of the feasibility, safety and physiological implications of autoregulation-guided CPP management is providing evidence that will be useful in the design of a future phase III study in severe TBI patients.Intracranial pressure (ICP) is an important invasive monitoring parameter in management of patients with acute brain injury and compromised compliance. This study aimed to compare waveforms obtained from standard ICP monitoring and noninvasive ICP monitoring (nICP) methods.We analyzed continuous arterial blood pressure (ABP) waves, ICP (with standard monitoring), and nICP recorded simultaneously. All signal recordings were sliced into data chunks, each 1 min in duration, and from the mean pulse, we determined the time to peak (Tp) and the ratio between tidal and percussion waves (P2/P1). We also calculated the Isomap projection of the pulses into a bidimensional space-K1 and K2. The defined nICP and ICP parameters were compared using a unilateral Wilcoxon-Mann-Whitney test. The Pearson correlation coefficient and normalized mutual information were used to verify the association between parameters.In total, 1504 min of monitoring from ten patients were studied. Nine of the patients were male. The mean age of the patients was 58.4 ± 10.4 years, and they had an initial Glasgow Coma Scale of 9 ± 4, a mean Simplified Acute Physiology Score (SAPS II) of 45.6, and an intensive care unit stay of 44 ± 45 days. With the exception of Tp, all parameters showed a weak linear association but presented a strong nonlinear association.Mutual information analysis and a bigger sample size would be helpful to build more refined models and to improve understanding of the waveform relationships.Transcranial Doppler ultrasound (TCD) enables assessment of brain hemodynamics through insonation of cerebral arteries and veins. Few studies have investigated whether the normal ranges of flow velocities in both arterial and venous compartments may be affected by age and sex.The purpose of this study was to determine the normal blood flow velocities across different sex and age subgroups in a cohort of healthy volunteers by studying the middle cerebral arteries (MCAs) and the straight sinus (SS).A total of 122 healthy volunteers undergoing preanesthetic assessment were recruited at Galliera Hospital in Genoa, Italy. The cohort was stratified for sex (males and females) and for age (18-44 years, 45-64 years, and ≥65 years). Data on systolic, diastolic, and mean flow velocities (FVs, FVd, and FVm, respectively) in the MCA and peak venous flow velocity in the SS (FVVs) were collected from each volunteer.The arterial FVs and FVm were significantly higher in males than in females; FVs, FVm, FVd, and FVVs increased across the age spectrum, especially in the elderly female population.Our findings suggest that there are differences in cerebrovascular flow velocities due to age and sex, which may be correlated to hormonal variations during the lifespan.Intracranial hypertension (IH) is an important cause of secondary brain injury, and its association with poor outcomes has been extensively demonstrated. Pathological intracranial hypertension is defined as a persistent rise in intracranial pressure (ICP) to above 20-25 mmHg, with symptoms such as headaches, loss of consciousness, seizures, and focal deficits, as well as ischemic damage. Therefore, monitoring of ICP is invaluable in the management of these symptoms. However, invasive measurements of ventricular pressure (requiring a surgical procedure) are considered the gold standard, thus limiting the practicality of ICP measurements. Vivonics, Inc., is developing a noninvasive optical device to assess ICP for use by emergency medical personnel, called IPASS Intracranial Pressure Assessment and Screening System. IPASS uses four near-infrared sensors to measure hemodynamic oscillations at four different locations. MMRi62 are used as reference signals and one sensor is used to detect cerebral blood volume oscillations. Pulse arrival delays between the measured cerebral blood volume oscillations and the blood volume oscillations measured at the three reference locations are calculated and correlated with estimated ICP changes, herein modulated by specific positional changes (in a head-down maneuver).Many studies have demonstrated that the optic nerve sheath diameter (ONSD) is a good indicator of intracranial pressure (ICP). There are uncertainties regarding the optimal ONSD threshold, considering age and sex differences in the healthy population, and these differences could lead to uncertainties in evaluation of ONSD in pathological conditions.The aim of this prospective observational study was to investigate if age and sex could influence ONSD in a cohort of healthy Italian volunteers recruited during preanesthetic assessment for low-risk surgical procedures.The population was stratified for sex (males versus females) and for age (18-44 years, 45-64 years, and ≥65 years). The axial and longitudinal ONSD diameters were measured by two trained investigators.A significant difference in ONSD between males and females was found (median 4.2 (interquartile range 3.9-4.6) versus 4.1 (interquartile range 3.6-4.2) mm, P = 0.01), and a positive correlation between ONSD and age was found (R = 0.50, P less then 0.