Intracranial Pressure Levels Research Articles

The S-100B level, intracranial pressure, body temperature, and transcranial blood flow velocities predict the outcome of the treatment of severe brain injury.

This study evaluates the applicability of S100B levels, mean maximum velocity (Vmean) over time, pulsatility index (PI), intracranial pressure (ICP), and body temperature (T) for the prediction of the treatment of patients with traumatic brain injury (TBI). Sixty patients defined by the Glasgow Coma Scale score ≤ 8 were stratified using the Glasgow Coma Scale into 2 groups: favorable (FG: Glasgow Outcome Scale ≥ 4) and unfavorable (UG: Glasgow Outcome Scale < 4). The S100B concentration was at the time of hospital admission. Vmean was measured using transcranial Doppler. PI was derived from a transcranial Doppler examination. T was measured in the temporal artery. The differences in mean between FG and UG were tested using a bootstrap test of 10,000 repetitions with replacement. Changes in S100B, Vmean, PI, ICP, and T levels stratified by the group were calculated using the one-way aligned rank transform for nonparametric factorial analysis of variance. The reference ranges for the levels of S100B, Vmean, and PI were 0.05 to 0.23 µg/L, 30.8 to 73.17 cm/s, and 0.62 to 1.13, respectively. Both groups were defined by an increase in Vmean, a decrease in S100B, PI, and ICP levels; and a virtually constant T. The unfavorable outcome is defined by significantly higher levels of all parameters, except T. A favorable outcome is defined by S100B < 3 mg/L, PI < 2.86, ICP > 25 mm Hg, and Vmean > 40 cm/s. The relationships provided may serve as indicators of the results of the TBI treatment.

Prognostic predictive value of intracranial pressure and cerebral oxygen metabolism monitoring in patients with spontaneous intracerebral hemorrhage

ObjectiveOur study aimed to investigate the predictive value of intracranial pressure (ICP) and cerebral oxygen metabolism monitoring in the postoperative prognosis of patients with spontaneous intracerebral hemorrhage (SICH).MethodsThe clinical data of 55 patients with SICH treated by neurosurgery were analyzed retrospectively. These patients were divided into two groups based on postoperative Glasgow Outcome Scale (GOS) scores, i.e., the poor prognosis group (GOS I-III) and the good prognosis group (GOS IV and V). Next, the ICP and cerebral oxygen metabolism indexes, such as brain temperature (BT), cerebral perfusion pressure (CPP), internal jugular venous oxygen saturation (SjvO2), and arterial partial pressure of carbon dioxide (PaCO2), were recorded after the operation. Further, the prognostic differences between the two groups were compared, and the predictive values were evaluated using the receiver operating characteristic curve (ROC) and area under the curve (AUC).ResultsThe results showed that the average ICP and BT in the good prognosis group were lower than those in the poor prognosis group. However, the CPP and SjvO2 in the good prognosis group were higher than those in the poor prognosis group. Moreover, the incidence of low PaCO2 in the poor prognosis group was higher than that in the good prognosis group.ConclusionsOur results demonstrated that the average ICP, BT, CPP, SjvO2, and arterial PaCO2 may reflect the changes in brain function and cerebral blood flow, which are significantly correlated with the prognosis of patients. Further, our findings indicated that the combined postoperative ICP levels with cerebral oxygen metabolism indexes could guide clinical treatments and predict prognosis.

Effect of Angong Niuhuang pill combined with mild therapeutic hypothermia on acute cerebral hemorrhage in patients

Purpose: To investigate the effect of Angong Niuhuang pill combined with mild therapeutic hypothermia on acute cerebral hemorrhage.Methods: From July 2017 to December 2020, 118 patients with acute cerebral hemorrhage treated in Dongying Honggang Hospital were recruited and assigned randomly to receive either routine treatment (control group, n = 59) or Angong Niuhuang Pill plus mild therapeutic hypothermia (study group, n = 59).Results: The study group showed a higher treatment efficacy (98.31 %) than the control group (82.78 %, p &lt; 0.001). After treatment, patients in the study group achieved significantly higher Glasgow Coma Scale (GCS) scores (13.01 ± 2.31) and a lower intracranial pressure (14.25 ± 3.12) versus those in the control group (10.18 ± 2.05, 18.15 ± 3.05, respectively, p &lt; 0.001). The study group displayed lower blood glucose and blood pressure levels than the control group (p &lt; 0.001).Conclusion: Combined Angong Niuhuang Pill and mild therapeutic hypothermia therapy in patients with acute cerebral hemorrhage significantly improves treatment efficacy, as well as reduces intracranial pressure, blood sugar, blood pressure, and tumor marker levels in the patients. It also improves the ability of daily living of the patients and lowers the incidence of adverse reactions.

Inducing oscillations in positive end-expiratory pressure improves assessment of cerebrovascular pressure reactivity in patients with traumatic brain injury.

The cerebral pressure reactivity index (PRx), through intracranial pressure (ICP) measurements, informs clinicians about the cerebral autoregulation (CA) status in adult-sedated patients with traumatic brain injury (TBI). Using PRx in clinical practice is currently limited by variability over shorter monitoring periods. We applied an innovative method to reduce the PRx variability by ventilator-induced slow (1/min) positive end-expiratory pressure (PEEP) oscillations. We hypothesized that, as seen in a previous animal model, the PRx variability would be reduced by inducing slow arterial blood pressure (ABP) and ICP oscillations without other clinically relevant physiological changes. Patients with TBI were ventilated with a static PEEP for 30 min (PRx period) followed by a 30-min period of slow [1/min (0.0167 Hz)] +5 cmH2O PEEP oscillations (induced (iPRx period). Ten patients with TBI were included. No clinical monitoring was discontinued and no additional interventions were required during the iPRx period. The PRx variability [measured as the standard deviation (SD) of PRx] decreased significantly during the iPRx period from 0.25 (0.22-0.30) to 0.14 (0.09-0.17) (P = 0.006). There was a power increase around the induced frequency (1/min) for both ABP and ICP (P = 0.002). In conclusion, 1/min PEEP-induced oscillations reduced the PRx variability in patients with TBI with ICP levels <22 mmHg. No other clinically relevant physiological changes were observed. Reduced PRx variability might improve CA-guided perfusion management by reducing the time to find "optimal" perfusion pressure targets. Larger studies with prolonged periods of PEEP-induced oscillations are required to take it to routine use.NEW & NOTEWORTHY Cerebral autoregulation assessment requires sufficient slow arterial blood pressure (ABP) waves. However, spontaneous ABP waves may be insufficient for reliable cerebral autoregulation estimations. Therefore, we applied a ventilator "sigh-function" to generate positive end-expiratory pressure oscillations that induce slow ABP waves. This method demonstrated a reduced variability of the pressure reactivity index, commonly used as continuous cerebral autoregulation measure in a traumatic brain injury population.

The Prognostic Value of Deleted in Colorectal Cancer (DCC) Receptor and Serum Netrin-1 in Severe Traumatic Brain Injury.

Traumatic brain injury (TBI) is a common neurological disease. Netrin-1 and deleted in colorectal cancer (DCC) receptor are potential biomarkers associated with nerve regeneration and immune regulation. We aimed to investigate the ability of the DCC receptor and Netrin-1 to predict a high ICP level after operation in severe traumatic brain injury and their prognostic significance. This study is a prospective observational study. We selected 23 patients with traumatic brain injury who had undergone surgical operations as subjects. Immunohistochemical staining was performed on the contusion tissue that was removed by the operation to determine the expression of DCC receptor. At the same time, enzyme-linked immunosorbent assay (ELISA) kits were used to detect the serum Netrin-1 content. Determination of intracranial pressure (ICP) value was measured by intraventricular catheter. The Glasgow Outcome Scale (GOS) score at six months after trauma was defined as the main study endpoint. The results showed that serum Netrin-1 concentrations of patients in the critical TBI group (GCS 3–5 points) was significantly lower than that in the severe TBI group (GCS 6–8 points). The ICP peak and average mannitol consumption in the high Netrin-1 group were significantly lower than those in the low Netrin-1 group. DCC receptor-positive patients had a significantly lower ICP peak. There was no significant difference in six month-GOS scores between patients in the high and low Netrin-1 groups, while DCC receptor concentrations below 3.82 ng/mL predicted poor prognosis (GOS 1–3 points). In conclusion, the expression level of the DCC receptor can better evaluate the postoperative high ICP level and prognosis than the level of serum Netrin-1 in severe traumatic brain injury.

Probabilistic prediction of increased intracranial pressure in patients with severe traumatic brain injury

Traumatic brain injury (TBI) causes alteration in brain functions. Generally, at intensive care units (ICU), intracranial pressure (ICP) is monitored and treated to avoid increases in ICP with associated poor clinical outcome. The aim was to develop a model which could predict future ICP levels of individual patients in the ICU, to warn treating clinicians before secondary injuries occur. A simple and explainable, probabilistic Markov model was developed for the prediction task ICP ≥ 20 mmHg. Predictions were made for 10-min intervals during 60 min, based on preceding hour of ICP. A prediction enhancement method was developed to compensate for data imbalance. The model was evaluated on 29 patients with severe TBI. With random data selection from all patients (80/20% training/testing) the specificity of the model was high (0.94–0.95) and the sensitivity good to high (0.73–0.87). Performance was similar (0.90–0.95 and 0.73–0.89 respectively) when the leave-one-out cross-validation was applied. The new model could predict increased levels of ICP in a reliable manner and the enhancement method further improved the predictions. Further advantages are the straightforward expandability of the model, enabling inclusion of other time series data and/or static parameters. Next step is evaluation on more patients and inclusion of parameters other than ICP.

Predictive Value of Optic Nerve Sheath Diameter for Diagnosis of Intracranial Hypertension in Children With Severe Brain Injury.

Background and AimsIntracranial Hypertension (ICH) is a life-threatening complication of brain injury. The invasive measurement of intracranial pressure (ICP) remains the gold standard to diagnose ICH. Measurement of Optic Nerve Sheath Diameter (ONSD) using ultrasonography is a non-invasive method for detecting ICH. However, data on paediatric brain injury are scarce. The aim of the study was to determine the performance of the initial ONSD measurement to predict ICH occurring in children with severe brain injury and to describe the ONSD values in a control group.MethodsIn this cross-sectional study, ONSD was measured in children aged 2 months-17 years old with invasive ICP monitoring: before placement of ICP probe and within the 60 min after, and then daily during 3 days. ONSD was also measured in a control group.ResultsNinety-nine patients were included, of whom 97 were analysed, with a median (IQR) age of 8.7 [2.3–13.6] years. The median (IQR) PIM 2 score was 6.6 [4.4–9.7] and the median (IQR) PELOD score was 21 [12–22]. Aetiologies of brain injury were trauma (n = 72), infection (n = 17) and stroke (n = 8). ICH occurred in 65 children. The median (IQR) ONSD was 5.58 mm [5.05–5.85]. ONSD performed poorly when it came to predicting ICH occurrence within the first 24 h (area under the curve, 0.58). There was no significant difference between the ONSD of children who presented with ICH within the first 24 h and the other children, with a median (IQR) of 5.6 mm [5.1–5.9] and 5.4 mm [4.9–5.8], respectively. Infants aged less than 2 years had a median (IQR) ONSD of 4.9 mm [4.5–5.2], significantly different from children aged more than 2 years, whose median ONSD was 5.6 mm [5.2–5.9]. Age, aetiology or ICP levels did not change the results. Thirty-one controls were included, with a median age of 3.7 (1.2–8.8) years. The median (IQR) of their ONSD measurement was 4.5 mm [4.1–4.8], significantly lower than the patient group.ConclusionIn a paediatric severe brain injury population, ONSD measurement could not predict the 24 h occurrence of ICH. Severity of patients, timing and conditions of measurements may possibly explain these results.

Noninvasive assessment of intracranial pressure using subharmonic-aided pressure estimation: An experimental study in canines.

Intracranial hypertension is a common clinicopathological syndrome in neurosurgery, and a timely understanding of the intracranial pressure (ICP) may help guide clinical treatment. We aimed to investigate the correlation between subharmonic contrast-enhanced ultrasound (SHCEUS) parameters and ICP in experimental canines. A dynamic model of ICP change from 11 mm Hg to 50 mm Hg was established in experimental canines by placing a latex balloon into the epidural space and injecting saline into the balloon. In addition, a pressure sensor was placed in the brain parenchyma to record the changes in ICP. When the ICP stabilized after each increase, subharmonic-aided pressure estimation (SHAPE) technology was performed to obtain the SHCEUS parameters, including the basal venous and adjacent intracranial arterial subharmonic amplitude and SHAPE gradient (subharmonic amplitude in the intracranial artery minus that in the basal vein). The correlation between these parameters and ICP was analyzed. The subharmonic amplitude of the basal vein was negatively correlated with the ICP (r = -0.798), and the SHAPE gradient was positively correlated with the ICP (r = 0.628). According to the guidelines for ICP monitoring in patients with traumatic brain injury, we defined 20 mm Hg, 25 mm Hg, and 30 mm Hg as the cutoff ICP levels. The area under the receiver operating characteristic curve of the basal venous subharmonic amplitude for diagnosing intracranial hypertension ≥20 mm Hg, ≥25 mm Hg, and ≥30 mm Hg was 0.867 (95% confidence interval [CI], 0.750-0.943), 0.884 (95% CI, 0.770-0.954), and 0.875 (95% CI, 0.759-0.948), respectively. The area under the receiver operating characteristic curve of the SHAPE gradient for diagnosing intracranial hypertension ≥20 mm Hg, ≥25 mm Hg, and ≥30 mm Hg was 0.839 (95% CI, 0.716-0.924), 0.842 (95% CI, 0.720-0.926), and 0.794 (95% CI, 0.665-0.890), respectively. SHCEUS parameters are correlated with ICP. The SHAPE technique can assist in evaluating ICP changes in canines, which provides a new idea and method for evaluating ICP.

Characterizing Brain Perfusion in a Swine Model of Raised Intracranial Pressure

IntroductionPerfusion of the brain is critical, but this can be compromised due to focal space occupying lesions (SOL). SOLs can raise intracranial pressure (ICP), resulting in reduced cerebral blood flow (CBF). Most gyrencephalic models of brain injury focus on parenchymal injury, with few models of acutely elevated ICP. We hypothesized that we could employ a SOL technique to develop a titratable ICP model and sought to quantitate the resulting decrease in brain perfusion. MethodsSix swine were anesthetized and instrumented. A Fogarty balloon catheter was inserted intracranially. Blood CO2 partial pressure was maintained between 35 and 45 mmHg. The Fogarty balloon was infused with normal saline at 1 mL/min to ICP targets of 10, 20, 30, and 40 mmHg. CBF (mL/100 g/min) were assessed at each ICP level using computed tomography perfusion (CTP). Data are presented as the mean ± standard deviation with all pressures measured in mmHg. CBF values were compared between baseline and each ICP level using analysis of variance. ResultsBaseline ICP was 5 ± 2 and systolic blood pressure was 106 ± 7. Balloon volumes (mL) required to achieve each incremental ICP level were 2.4 ± 0.5, 4.9 ± 1.7, 7.6 ± 1.6, and 9.9 ± 1.7. CBF decreased with each raised ICP level, with CBF being significantly less than baseline at ICP values of 30 (56.1 ± 34.7 versus 20.6 ± 11.0, P < 0.05) and 40 (56.1 ± 34.7 versus 6.5 ± 10.6, P < 0.05). ConclusionsAn intracranial balloon catheter can be used to increase ICP, delivering a proportionate reduction in CBF. This model can be used in the future studies to examine adjuncts that manipulate intracranial pressure and their effect on brain perfusion.

Optic nerve ultrasound and cardiopulmonary bypass: A pilot study.

Introduction:Despite advances in surgical, anesthetic, perfusion, and postoperative care, adverse neurological consequences may occur following cardiac surgery and cardiopulmonary bypass (CPB). Consequences of the physiologic effects of CPB may alter the blood–brain barrier, autoregulation, and intracranial pressure (ICP) in the immediate postoperative period.Methods:We evaluated the effects of cardiac surgery and CPB on the central nervous system by measuring the optic nerve sheath diameter (ONSD) by using ultrasound as a surrogate marker of ICP. ONSD was measured after anesthetic induction and endotracheal intubation (time 1), after separation from CPB (time 2), and at the completion of the surgical procedure prior to leaving the OR (time 3).Results:The study cohort included 14 patients, ranging in age from newborn to 6 years. When comparing the Fontan group (n = 5) to the non-Fontan group (n = 9), four elevated ONSD observations were recorded for the Fontan patients during the study period, including one at time 1, one at time 2, and two at time 3. In Fontan versus non-Fontan patients, ONSD was greater at all three time points compared to non-Fontan. The change in the ONSD from time 1 to time 2 was greater (+0.2 mm vs. −0.1 mm), and the mean value at time 2 was significantly higher (4.2 vs. 3.5 mm, P = 0.048).Conclusions:Patients with Fontan physiology may be more prone to higher levels of baseline intracranial pressure due to elevated systemic venous pressure and decreased cardiac output. Alternatively, the chronically high central venous pressures may artificially elevate ONSD without clinical changes in ICP, necessitating the development of separate normative values based on the type of congenital heart disease.

Where to Draw the Line for Intracranial Hypertension; Opening Pressures and Mortality.

Intracranial pressure (ICP) monitoring and treatment is a mainstay of severe TBI management but the relationship between intracranial opening pressure (OP) and outcomes has not been well established. The purpose of our study was to assess the relationship between OP and outcomes in severe TBI patients, with a focus on in-hospital mortality. Adult blunt TBI patients with ICP monitoring between 2007 and 2017 were evaluated using sequential multivariable binary logistic modeling. Generalized additive model (GAM) was used to evaluate the relationship between OP and death. Odds ratio (OR) and 95% confidence interval (CI) were calculated for measures of strength of association and precision. A total of 182 patients were identified, with 61 (33.5%) having OP >20mmHG (overall mean ± OP = 19.4 ± 17.8mmHG). Forty-eight percent, 9% and 8% of patients were discharged to rehabilitation, skilled nursing institution, and home, respectively. Thirty-five percent died in the hospital. A linear relationship was found between OP and log-odds of mortality. OP (OR = 1.07; 95% CI = 1.04-1.11), age (OR = 1.05;95%CI = 1.02-1.07), and injury severity score (ISS) (OR = 1.06; 95% CI = 1.02-1.10) were independently associated with increased odds of death while adjusting for sex, race, and year. Elevated opening pressure is strongly predictive of death in severe TBI. Age and ISS are independent predictors of mortality regardless of OP. These results suggest that maintaining low levels of ICP should result in decreased mortality in severe TBI patients. The patient's age and ISS should be considered in the decision-making processes related to ICP utilization and management.

Association between pro-inflammatory cytokines in cerebrospinal fluid and headache in patients with aneurysmal subarachnoid hemorrhage

ObjectiveTo investigate the relationship between the dynamic changes of pro-inflammatory cytokines in cerebrospinal fluid (CSF) and headache in patients with aneurysmal subarachnoid hemorrhage (aSAH)at hospital admission. MethodsCSF was collected from patients with aSAH at four time points (days 1, 3, 5, and 7; n = 216) from January 2017 to August 2017 at the Department of Neurosurgery of the First Affiliated Hospital of Wannan Medical College. We measured CSF levels ofinterleukin-1β (IL-1β), IL-6, IL-8, and tumor necrosis factor-alpha (TNF-α) levels using an enzyme-linked immunosorbent assay. Results were statistically analyzed to determine the relationship between the dynamic changes of pro-inflammatory cytokines in CSF and headache after aSAH. ResultsThe concentrations of IL-1β, IL-6, IL-8, and TNF-α in CSF showed dynamic changes after aSAH. Spearman correlation coefficient analysis revealed that high Hunt-hess grade and modified Fisher scale were associated with a worse headache after aSAH on days 1 and 7 (all P < 0.05). High values of intracranial pressure (ICP) and high levels of CSF pro-inflammatory cytokines were associated with a worse headache after aSAH at four time points (all P < 0.05). However, no significant associations were found between headache and sex, and age. After multiple regression analysis, the Hunt-hess grade, the levels of IL-6 and the levels of TNF-α were associated with headache severity at day 1 (all P < 0.05). The ICP, the levels of IL-1β and the levels of TNF-α were associated with headache severity on day 3, 5 and 7 (all P < 0.05). ConclusionsPro-inflammatory cytokines in CSF are closely associated with a headache after aSAH, and therefore may be a therapeutic target in the future.

End-to-End Automatic Morphological Classification of Intracranial Pressure Pulse Waveforms Using Deep Learning.

Mean intracranial pressure (ICP) is commonly used in the management of patients with intracranial pathologies. However, the shape of the ICP signal over a single cardiac cycle, called ICP pulse waveform, also contains information on the state of the craniospinal space. In this study we aimed to propose an end-to-end approach to classification of ICP waveforms and assess its potential clinical applicability. ICP pulse waveforms obtained from long-term ICP recordings of 50 neurointensive care unit (NICU) patients were manually classified into four classes ranging from normal to pathological. An additional class was introduced to simultaneously identify artifacts. Several deep learning models and data representations were evaluated. An independent testing dataset was used to assess the performance of final models. Occurrence of different waveform types was compared with the patients' clinical outcome. Residual Neural Network using 1-D ICP signal as input was identified as the best performing model with accuracy of 93% in the validation and 82% in the testing dataset. Patients with unfavorable outcome exhibited significantly lower incidence of normal waveforms compared to the favorable outcome group even at ICP levels below 20 mm Hg (median [first-third quartile]: 9 [1-36]% vs. 63 [52-88] %, p = 0.002). Results of this study confirm the possibility of analyzing ICP pulse waveform morphology in long-term recordings of NICU patients. Proposed approach could potentially be used to provide additional information on the state of patients with intracranial pathologies beyond mean ICP.

Clinical value of bedside transcranial doppler ultrasound in assessing intracranial pressure in critically ill pediatric patients with nervous system disease

To study the value of bedside transcranial doppler (TCD) in evaluating the level of intracranial pressure (ICP) in critically ill pediatric patients with nervous system disease in the pediatric intensive care unit (PICU). A prospective analysis was performed on the critically ill pediatric patients with nervous system disease who were admitted to the PICU of Shengjing Hospital, China Medical University, from November 2020 to November 2021. Bedside TCD was performed on all patients, and pulsatility index (PI) was calculated. Bedside lumbar puncture was performed to measure ICP. A Pearson correlation analysis was used to assess the correlation between PI and ICP. The receiver operating characteristic (ROC) curve was used to assess the value of PI in the diagnosis of elevated ICP (≥20 mm Hg). A total of 56 children were included in the study. The top three primary diseases were intracranial infection (24 children, 43%), traumatic brain injury (TBI) (11 children, 20%), and cerebrovascular disease (5 children, 9%). The Pearson correlation analysis showed that PI was positively correlated with ICP (r=0.536, P<0.001). The subgroup analysis based on primary disease showed that in the TBI group, PI was positively correlated with ICP (r=0.655, P=0.029), while no significant correlation between PI and ICP was observed in the intracranial infection group (r=0.324, P=0.122). The ROC curve analysis showed that PI had an area under the curve of 0.828 (95%CI: 0.677-0.979) in predicting ICP≥20 mm Hg, with a sensitivity of 83.3% and a specificity of 79.5% at the optimal cut-off value of 1.255. TCD technology for ICP monitoring can predict the change in ICP in critically ill pediatric patients with nervous system disease, suggesting it is useful for treatment options and prognosis evaluation.

Ultrasonographic Measurement of Optic Nerve Sheath Diameter in Patients Undergoing Open Heart Surgery: A Prospective Cross-sectional Study

Introduction: Adverse neurologic outcomes following cardiac surgery can be catastrophic to the patient, next of kin, healthcare facility and community at large. Ultrasonographic measurement of Optic Nerve Sheath Diameter (ONSD) has emerged as a promising modality to reflect Intracranial Pressure (ICP) and neurological status in various neurological settings. Aim: To explore ONSD as a tool to reflect ICP changes and predict neurologic outcomes in a cardiac surgical perioperative setting during Cardiopulmonary Bypass (CPB). Materials and Methods: This was an open-label, prospective and observational study conducted in Department of Anaesthesia, Command Hospital, Karnataka, India, from June 2016 to July 2018. All patients aged between 15 and 80 years who underwent open heart surgeries irrespective of gender, primary diagnosis and preoperative American society of Anaesthesiologist’s Physical Status (ASA PS) grade were enrolled in the study. Serial ultasonographic ONSD of both eyes in two planes (viz. sagittal and transverse) were acquired by a single observer at the following time intervals: baseline (prior to general anaesthesia induction, immediately postintubation, and every 15 minutes interval during CPB (until 150 minutes or end of the CPB whichever was earlier). Postoperative neurologic reassessment was done at 6 hours/postextubation (whichever earlier), at 24 hours and after 7 days, postoperatively. Continuous variables were compared using the student t-tests, while Chi-square or Fisher’sexact test was used to compare categorical variables. To assess inter-rater reliability for categorical variables, the Cohen’s Kappa statistic was used. Results: The mean age of the study cohort was 56.30±11.42 years. A slight male preponderance (56%) was observed. With regards to mean of total CPB time, it was insignificantly higher in patients with adverse neurologic outcomes as compared to those without adverse neurological outcomes (165.83±53.61 minutes vs. 121.36±21.41 minutes; p-value=0.098). Patients with adverse neurologic outcomes had significantly higher ONSD (average of both planes) on CPB from 60 minutes through 150 minutes/end of CPB timeline for right eye (p-value &lt; 0.001), left eye (p-value &lt;0.001), and both eyes (p-value &lt;0.001). For patients with ONSD value (average of both eyes in both planes of each eye) ≥5.5 mm had more likelihood to develop adverse neurologic outcomes, postoperatively. With respect to maximum ONSD anytime during CPB (average of both eyes in both planes of each eye), an arbitrary cut-off of ≥5.5 mm showed a sensitivity of 100%, specificity of 95%, diagnostic accuracy of 100%, and predictive value of 100% with significant p-value of &lt;0.001. Conclusion: Serial ultrasonographic ONSD measurement is assuredly a promising tool to monitor elevated level of ICP as well as a good predictor for the assessment of major adverse neurologic outcomes secondary to open heart cardiac surgeries.

Noninvasive evaluation of intracranial pressure in patients with traumatic brain injury by transcranial Doppler ultrasound.

IntroductionThe purpose of this study was to investigate the relationship between pulsatility index (PI) or optic nerve sheath diameter (ONSD) and intracranial pressure (ICP) in patients with traumatic brain injury (TBI), and the ability of ONSD and ICP to predict intracranial hypertension.MethodsA total of 68 patients with TBI were included in this retrospective study. After receiving surgery treatment, they underwent transcranial Doppler ultrasound (TCD). The statistical correlation between PI or ONSD and ICP 1 week after surgery was analyzed. Furthermore, the areas under the curve (AUCs) of ONSD or PI or a combination of them were calculated to predict intracranial hypertension.ResultsThere was a correlation between ONSD and ICP. This correlation still remained at ONSD ≥ 5 mm. Furthermore, there was a strong correlation between PI and ICP. There was a moderate correlation between ICP and PI on days 3, 4, and 5 after surgery (r = 0.508, p < .001), and a strong correlation on days 6 and 7 after surgery (r = 0.645, p < .001). Moreover, for predicting intracranial hypertension with PI ≥ 1.2 mm or ONSD ≥ 5 mm or a combination of them, the AUC was 0.729, 0.900, and 0.943, respectively (p < .001).ConclusionsThe correlation between ONSD or PI and invasive ICP was different with different levels of ICP in different periods in patients with TBI after surgery. When ONSD ≥ 5 mm and PI ≥ 1.2, it could predict elevated ICP more accurately.

Brain tissue oxygenation guided therapy and outcome in non-traumatic subarachnoid hemorrhage

Brain hypoxia can occur after non-traumatic subarachnoid hemorrhage (SAH), even when levels of intracranial pressure (ICP) remain normal. Brain tissue oxygenation (PbtO2) can be measured as a part of a neurological multimodal neuromonitoring. Low PbtO2 has been associated with poor neurologic recovery. There is scarce data on the impact of PbtO2 guided-therapy on patients’ outcome. This single-center cohort study (June 2014–March 2020) included all patients admitted to the ICU after SAH who required multimodal monitoring. Patients with imminent brain death were excluded. Our primary goal was to assess the impact of PbtO2-guided therapy on neurological outcome. Secondary outcome included the association of brain hypoxia with outcome. Of the 163 patients that underwent ICP monitoring, 62 were monitored with PbtO2 and 54 (87%) had at least one episode of brain hypoxia. In patients that required treatment based on neuromonitoring strategies, PbtO2-guided therapy (OR 0.33 [CI 95% 0.12–0.89]) compared to ICP-guided therapy had a protective effect on neurological outcome at 6 months. In this cohort of SAH patients, PbtO2-guided therapy might be associated with improved long-term neurological outcome, only when compared to ICP-guided therapy.

Correlations between optic nerve sheath diameters measured using computed tomography and elevated intracranial pressure levels

BackgroundIncreased intracranial pressure (ICP) is commonly encountered in neurosurgery. Invasive external ventricular drainage is the gold standard ICP monitoring method. Higher ICPs enlarge the optic nerve sheath diameter (ONSD). Currently, few data describing correlations between ONSDs measured using computed tomography and ICPs. This manuscript describes a study that aimed to evaluate associations between the ICP and the ONSD measured using head CT, and to determine the ability of the ONSD to predict intracranial hypertension. ObjectivesWe aimed to study correlations between ONSDs and ICPs in patients who underwent ventricular shunting procedures, and to determine ONSD cutoff values that represent ICPs >15 mmHg and >20 mmHg, together with their sensitivities, specificities, negative predictive values (NPVs), and positive predictive values (PPVs). MethodsThe patients’ charts, operative notes, and brain computed tomography (CT) findings were reviewed retrospectively. The ONSDs were measured at 3 mm behind the globes on axial CT images from 102 patients who underwent ventricular shunting. Intraoperative ICP data were collected. ResultsA total of 102 patients were enrolled, comprising 93 (91.2%) without and 9 (8.8%) with traumatic brain injuries. Their mean age was 56.95 years (SD 17.01 years). The most common diagnoses were spontaneous intracerebral hemorrhages (ICH) with or without hydrocephalus (30 [29.4%]) and aneurysmal subarachnoid hemorrhages (SAH) (19 [18.6%]). The mean preoperative ONSD was 4.875 mm (SD 0.96 mm). The ONSD correlated significantly with the ICP levels (p < 0.001). An ONSD cutoff value of 5.125 mm predicted an ICP >15 mmHg (sensitivity: 94.7%; specificity: 90.6%; PPV: 85.7%; NPV: 96.7%). An ONSD cutoff value of 5.35 mm corresponded with an ICP >20 mmHg (sensitivity: 94.7%; specificity: 84.3%; PPV: 58.1 %; NPV: 98.6%). The ONSD decreased significantly to within the normal range (4.17 mm [standard deviation (SD) 0.60 mm]; p < 0.001) at 27 days (SD 14.70 days) postoperatively. ConclusionsCT-determined ONSDs correlated strongly with invasive ICP measurements. An ONSD of 5.35 mm, which corresponded with an ICP >20 mmHg, could become a noninvasive, alternative indicator for ICP level.

Brain Temperature Influences Intracranial Pressure and Cerebral Perfusion Pressure After Traumatic Brain Injury: A CENTER-TBI Study

BackgroundAfter traumatic brain injury (TBI), fever is frequent. Brain temperature (BT), which is directly linked to body temperature, may influence brain physiology. Increased body and/or BT may cause secondary brain damage, with deleterious effects on intracranial pressure (ICP), cerebral perfusion pressure (CPP), and outcome.MethodsCollaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI), a prospective multicenter longitudinal study on TBI in Europe and Israel, includes a high resolution cohort of patients with data sampled at a high frequency (from 100 to 500 Hz). In this study, simultaneous BT, ICP, and CPP recordings were investigated. A mixed-effects linear model was used to examine the association between different BT levels and ICP. We additionally focused on changes in ICP and CPP during the episodes of BT changes (Δ BT ≥ 0.5 °C lasting from 15 min to 3 h) up or downward. The significance of ICP and CPP variations was estimated with the paired samples Wilcoxon test (also known as Wilcoxon signed-rank test).ResultsTwenty-one patients with 2,435 h of simultaneous BT and ICP monitoring were studied. All patients reached a BT of 38 °C and experienced at least one episode of ICP above 20 mm Hg. The linear mixed-effects model revealed an association between BT above 37.5 °C and higher ICP levels that was not confirmed for lower BT. We identified 149 episodes of BT changes. During BT elevations (n = 79) ICP increased, whereas CPP was reduced; opposite ICP and CPP variations occurred during episodes of BT reduction (n = 70). All these changes were of moderate clinical relevance (increase of ICP of 4.5 and CPP decrease of 7.5 mm Hg for BT rise, and ICP reduction of 1.7 and CPP elevation of 3.7 mm Hg during BT defervescence), even if statistically significant (p < 0.0001). It has to be noted, however, that a number of therapeutic interventions against intracranial hypertension was documented during those episodes.ConclusionsPatients after TBI usually develop BT > 38 °C soon after the injury. BT may influence brain physiology, as reflected by ICP and CPP. An association between BT exceeding 37.5 °C and a higher ICP was identified but not confirmed for lower BT ranges. The relationship between BT, ICP, and CPP become clearer during rapid temperature changes. During episodes of temperature elevation, BT seems to have a significant impact on ICP and CPP.

Evaluation of Intracranial Hypertension in Traumatic Brain Injury Patient: A Noninvasive Approach Based on Cranial Computed Tomography Features.

Background: Our purpose was to establish a noninvasive quantitative method for assessing intracranial pressure (ICP) levels in patients with traumatic brain injury (TBI) through investigating the Hounsfield unit (HU) features of computed tomography (CT) images. Methods: In this retrospective study, 47 patients with a closed TBI were recruited. Hounsfield unit features from the last cranial CT and the initial ICP value were collected. Three models were established to predict intracranial hypertension with Hounsfield unit (HU model), midline shift (MLS model), and clinical expertise (CE model) features. Results: The HU model had the highest ability to predict intracranial hypertension. In 34 patients with unilateral injury, the HU model displayed the highest performance. In three classifications of intracranial hypertension (ICP ≤ 22, 23–29, and ≥30 mmHg), the HU model achieved the highest F1 score. Conclusions: This radiological feature-based noninvasive quantitative approach showed better performance compared with conventional methods, such as the degree of midline shift and clinical expertise. The results show its potential in clinical practice and further research.