BACKGROUND: During gynecological laparoscopic surgery, pneumoperitoneum and the Trendelenburg position (TP) can lead to increased intracranial pressure (ICP). However, it remains unclear whether perioperative fluid therapy impacts ICP. The purpose of this research was to evaluate the impact of restrictive fluid (RF) therapy versus conventional fluid (CF) therapy on ICP in gynecological laparoscopic surgery patients by measuring the ratio of the optic nerve sheath diameter (ONSD) to the eyeball transverse diameter (ETD) using ultrasound.
METHODS: Sixty-four patients who were scheduled for laparoscopic gynecological surgery were randomly assigned to the CF group or the RF group. The main outcomes were differences in the ONSD/ETD ratios between the groups at predetermined time points. The secondary outcomes were intraoperative circulatory parameters (including mean arterial pressure, heart rate, and urine volume changes) and postoperative recovery indicators (including extubation time, length of post-anaesthesia care unit stay, postoperative complications, and length of hospital stay).
RESULTS: There were no statistically significant differences in the ONSD/ETD ratio and the ONSD over time between the two groups (all p > 0.05). From T2 to T4, the ONSD/ETD ratio and the ONSD in both groups were higher than T1 (all p < 0.001). From T1 to T2, the ONSD/ETD ratio in both groups increased by 14.3%. However, the extubation time in the RF group was shorter than in the CF group [median difference (95% CI) -11(-21 to -2) min, p = 0.027]. There were no differences in the other secondary outcomes.
CONCLUSIONS: In patients undergoing laparoscopic gynecological surgery, RF did not significantly lower the ONSD/ETD ratio but did shorten the tracheal extubation time, when compared to CF.
BACKGROUND: ChiCTR2300079284. Registered on December 29, 2023.

OBJECTIVE: To examine whether changes in biomarker concentrations in patients with idiopathic normal-pressure hydrocephalus (iNPH) during 72 h of external lumbar drainage (ELD) can differentiate between responders and non-responders.
METHODS: Twenty patients with clinical and neuroradiological signs of iNPH underwent ELD over a period of 72 h. During this period, changes in cerebrospinal fluid (CSF) concentrations of biomarkers (amyloid-β, total and phosphorylated tau proteins) and intracranial pressure were monitored, and the volume of drained CSF was measured. Changes in the concentrations of selected biomarkers at three time points (0, 36, and 72 h) during ELD were tested for association with changes in clinical condition.
RESULTS: Ten patients showed significant clinical improvement after ELD, quantified as a difference of two or more points on the Mini-Mental State Examination and/or Japanese iNPH grading scale. The concentration of all tested biomarkers increased during the first 36 h. Respondents had higher Aβ 1-42 at all time points, with a significant difference seen after 72 h. They also had a significantly higher Aβ1-42/Aβ1-40 ratio at all time points.
CONCLUSIONS: A gradual increase in Aβ 1-42 concentration during three-day ELD represents a possible positive prognostic factor for the placement of permanent CSF drainage in patients with iNPH.

Information about the morphology of the intracranial pressure waveform, as well as the variations in intracranial pressure (ICP) and compliance in pediatric patients are essential to diagnose and predict the progression of various neurological conditions. However, there is no information on the morphology of the IP waveform in neurologically healthy pediatric patients. In the present study, intracranial compliance was therefore analyzed in neurologically healthy patients with the aid of a noninvasive device. The study was an observational, cross-sectional study. Fifty-five neurologically healthy participants were included. Data on intracranial compliance with the patient in two positions, lying down (0°) and seated (45°), were collected with a noninvasive extracranial sensor, which allowed the intracranial pressure waveforms to be recorded. The values of the ratio P2/P1 were then analyzed. A questionnaire (with a scale from zero to ten, where ten corresponds to the highest level of satisfaction) was applied for patients to evaluate their satisfaction with the sensor. Patients were 10 years old (average), and most of them were (58%). Mean P2/P1 ratio was 0.94 (sd = 0.14) in the supine position and 0.91 (sd = 0.15) in the seated position. Participants were satisfied with the length of time for which the equipment was used (9.8, sd = 0.71). The device did not cause any discomfort. The noninvasive method used was well accepted by the patients. Intracranial compliance values were determined by analysis of the P2/P1 ratio in neurologically healthy pediatric population.Trial registration: Brazilian Registry of Clinical Trials Identifier: RBR-5j74ddg.

BACKGROUND: Mannitol is widely used in neurosurgical units to mitigate raised intracranial pressure and cerebral edema, crucial in postoperative management. Its hyperosmolar properties reduce brain extracellular fluid, thereby altering cerebral perfusion and cardiac dynamics. However, the temporal and combined effects of mannitol on cardiovascular and cerebrovascular parameters remain inadequately explored in postoperative settings.
METHODS: This prospective observational study enrolled 20 adult patients who underwent elective craniotomies for tumor excision. Mannitol was administered to the patients at a dose of 0.5 mg/kg/dose as a bolus dose over 20 to 30 minutes. The time interval was eight hours between the doses (scheduled dosing). Patients received their first dose of mannitol in the ICU after eight hours of intraoperative dose. The patients were given mannitol for two postoperative days and followed up for two days in the postoperative period. Transthoracic echocardiography and transcranial color Doppler were used to assess cardiovascular and cerebrovascular parameters at multiple intervals post-mannitol administration.
RESULTS: Significant increases in mean flow velocities were observed bilaterally immediately post-mannitol administration on the first postoperative day, indicative of improved cerebral blood flow. However, these changes were transient, with no significant variations noted on the second postoperative day. Cerebrovascular resistance, as measured by the pulsatility index, showed non-significant changes bilaterally across both days. Cardiovascular parameters, including stroke volume and cardiac output, remained stable throughout the study period.
CONCLUSIONS: Mannitol administration at 0.5 g/kg in postoperative neurosurgical patients transiently improves cerebral perfusion without causing significant hemodynamic instability. This study underscores the importance of monitoring both cerebrovascular and cardiovascular parameters post-mannitol administration to optimize patient management and outcomes.

BACKGROUND:  Patients with severe coronavirus disease-19 (COVID-19) may require the use of invasive mechanical ventilation (MV) for prolonged periods. Aggressive MV parameters have been associated with changes in intracranial pressure (ICP) in patients with acute intracranial disorders. Significant ICP elevation could compromise intracranial compliance (ICC) and cerebrovascular hemodynamics (CVH). However, the effects of these parameters in individuals without neurological disorders have not yet been evaluated.
OBJECTIVE:  To evaluate ICC in patients on MV with COVID-19 infection compared to other diagnoses, to better characterize the effects of MV and COVID-19 upon ICC. We also compared between the ICC in patients with COVID-19 who did not require MV and healthy volunteers, to assess the isolated effect of COVID-19 upon ICC.
METHODS:  This was an exploratory, observational study with a convenience sample. The ICC was evaluated with a noninvasive ICP monitoring device. The P2/P1 ratio was calculated by dividing the amplitude of these two points, being defined as \"abnormal\" when P2 > P1. The statistical analysis was performed using a mixed linear model with random effects to compare the P2/P1 ratio in all four groups on the first monitoring day.
RESULTS:  A convenience sample of 78 subjects (15 MV-COVID-19, 15 MV non-COVID-19, 24 non-MV-COVID-19, and 24 healthy participants) was prospectively enrolled. There was no difference in P2/P1 ratios between MV patients with and without COVID-19, nor between non-MV patients with COVID-19 and healthy volunteers. However, the P2/P1 ratio was higher in COVID-19 patients with MV use than in those without it.
CONCLUSIONS:  This exploratory analysis suggests that COVID-19 does not impair ICC.
BACKGROUND:  Pacientes com doença grave por coronavírus-19 (COVID-19) podem necessitar do uso de ventilação mecânica (VM) invasiva por um período prolongado. Parâmetros agressivos de VM têm sido associados a alterações na pressão intracraniana (PIC) em pacientes com doenças intracranianas agudas. Elevações significativas da PIC podem comprometer a complacência intracraniana (CIC) e a hemodinâmica cerebrovascular (HVC). No entanto, os efeitos desses parâmetros em indivíduos sem doenças neurológicas ainda não foram sistematicamente avaliados.
OBJECTIVE:  Avaliar a CIC em pacientes em VM com COVID-19 comparados com outros diagnósticos, para melhor caracterizar os efeitos da VM e COVID-19 sobre a CIC. Também foi feita a comparação entre a CIC em pacientes com COVID-19 sem VM e voluntários saudáveis, para avaliar o efeito isolado da COVID-19 sobre a ICC. MéTODOS:  Trata-se de um estudo exploratório, observacional com amostra por conveniência. A CIC foi avaliada com um dispositivo não invasivo de monitoramento da PIC. A relação P2/P1 foi calculada dividindo-se a amplitude desses dois pontos, sendo definida como “anormal” quando P2 > P1. A análise estatística foi realizada usando um modelo linear misto com efeitos aleatórios para comparar a relação P2/P1 nos quatro grupos no primeiro dia de monitoramento.
RESULTS:  Uma amostra de conveniência com 78 voluntários (15 COVID-19 em VM, 15 sem COVID-19 em VM, 24 com COVID em respiração espontânea e 24 saudáveis) foram prospectivamente incluídos. Não houve diferença nas razões P2/P1 entre pacientes em VM com e sem COVID-19, nem entre pacientes sem VM com COVID-19 ou saudáveis. No entanto, a relação P2/P1 foi maior em pacientes com COVID-19 com uso de VM do que naqueles sem. CONCLUSãO:  Os dados dessa análise exploratória sugerem que a COVID-19 não prejudica a CIC.

OBJECTIVE: The optic nerve sheath diameter (ONSD) is a commonly used estimate of intracranial pressure (ICP). The rationale behind this is that pressure changes in the cerebrospinal fluid affect the optic nerve subarachnoid space (ONSAS) thickness. Still, possible effects on other compartments of the optic nerve sheath (ONS) have not been studied. This is the first study ever to analyze all measurable compartments of the ONS for associations with elevated ICP.
METHODS: We measured changes in ICP and changes in ONS compartments in 75 patients treated with invasive ICP monitoring at the Karolinska University Hospital. Associations between changes in ICP and changes in ONS compartments were estimated with generalized estimating equations. The potential to identify elevated ICP was assessed with the area under the receiver operating characteristic curve (AUROC) for ONS compartments associated with ICP changes.
RESULTS: Both ONSAS and perioptic dura mater thickness were significantly associated with changes in ICP in multivariable modeling. ONSAS was the only compartment that independently predicted changes in ICP, with an AUROC of 0.69 for predicting ICP increase. Still, both the perioptic dura mater thickness and the optic nerve diameter added value in predicting ICP changes in multivariable modeling.
CONCLUSIONS: The results from this study challenge the current understanding of the mechanism behind the association between ICP and ONSD. Contrary to the common opinion that ONSAS is the only affected compartment, this study shows a more complex picture. It suggests that all ONS compartments may add value in predicting changes in ICP.

OBJECTIVE: An FDA-approved non-invasive intracranial pressure (ICP) monitoring system enables the assessment of ICP waveforms by revealing and analyzing their morphological variations and parameters associated with intracranial compliance, such as the P2/P1 ratio and time-to-peak (TTP). The aim of this study is to characterize intracranial compliance in healthy volunteers across different age groups.
METHODS: Healthy participants, both sexes, aged from 9 to 74 years old were monitored for 5 min in the supine position at 0º. Age was stratified into 4 groups: children (≤ 7 years); young adults (18 ≤ age ≤ 44 years); middle-aged adults (45 ≤ age ≤ 64 years); older adults (≥ 65 years). The data obtained was the non-invasive ICP waveform, P2/P1 ratio and TTP.
RESULTS: From December 2020 to February 2023, 188 volunteers were assessed, of whom 104 were male, with a median (interquartile range) age of 41 (29-51), and a median (interquartile range) body mass index of 25.09 (22.57-28.04). Men exhibited lower values compared to women for both the P2/P1 ratio and TTP (p < 0.001). There was a relative rise in both P2/P1 and TTP as age increased (p < 0.001).
CONCLUSIONS: The study revealed that the P2/P1 ratio and TTP are influenced by age and sex in healthy individuals, with men displaying lower values than women, and both ratios increasing with age. These findings suggest potential avenues for further research with larger and more diverse samples to establish reference values for comparison in various health conditions.
BACKGROUND: Brazilian Registry of Clinical Trials (RBR-9nv2h42), retrospectively registered 05/24/2022. UTN: U1111-1266-8006.

BACKGROUND: Early mobilization benefits critically ill patients, but concerns persist, especially in neurologic intensive care unit patients with acute brain injuries. This study assesses early mobility\'s impact on cerebrovascular autoregulation (CA) and systemic hemodynamics.
METHODS: This single-center retrospective study focused on adult neurologic intensive care unit patients undergoing passive cycle ergometry. Data were collected from December 2020 to April 2022. Physical therapists conducted sessions using a standardized protocol, monitoring mean arterial blood pressure (MAP) and intracranial pressure (ICP). The Pressure Reactivity Index (PRx) was calculated as a measure of CA. Statistical analysis included mixed models and repeated measures ANOVA.
RESULTS: Eleven patients undergoing continuous physiologic monitoring and early mobility were included, primarily with subarachnoid hemorrhage or intracranial hemorrhage. Median time to protocol initiation was 4 days, with two patients discontinuing due to hemodynamic disturbances. Over a total of 11-hours of neuromonitoring data, passive cycling demonstrated a significant reduction in heart rate (HR), MAP, and ICP across different rotations per minute (RPM) settings compared to baseline. No significant alterations in PRx or cerebral perfusion pressure (CPP) were noted at various RPM levels. However, a significant difference in PRx emerged between patients who completed the protocol and those who did not, particularly at 10 RPM.
CONCLUSIONS: This study offers preliminary insights into the impact of early mobility on CA in acute brain injured patients. While passive cycling demonstrates promise in preserving cerebral hemodynamics, its tolerability may not be uniform across all brain-injured patients. These findings highlight the need to determine optimal early mobilization timing and intensity in this population, emphasizing the necessity for larger prospective studies to validate these findings and inform clinical practice.
UNASSIGNED: This manuscript complies with all instructions to the authors. All coauthors meet the authorship requirements and have reviewed and approved the contents of the manuscript. The manuscript has not been published totally or partly, accepted for publication, or under editorial review for publication elsewhere. We have no conflicts of interest to disclose. STROBE checklist was reviewed prior to the submission of this paper. The manuscript adheres to ethical guidelines and was approved by Cleveland Clinic\'s institutional research board for retrospective study. There is no funding to disclose for this study.

BACKGROUND: Bacterial meningitis can cause a life-threatening increase in intracranial pressure (ICP). ICP-targeted treatment including an ICP monitoring device and external ventricular drainage (EVD) may improve outcomes but is also associated with the risk of complications. The frequency of use and complications related to ICP monitoring devices and EVDs among patients with bacterial meningitis remain unknown. We aimed to investigate the use of ICP monitoring devices and EVDs in patients with bacterial meningitis including frequency of increased ICP, drainage of cerebrospinal fluid (CSF), and complications associated with the insertion of ICP monitoring and external ventricular drain (EVD) in patients with bacterial meningitis.
METHODS: In a single-center prospective cohort study (2017-2021), we examined the frequency of use and complications of ICP-monitoring devices and EVDs in adult patients with bacterial meningitis.
RESULTS: We identified 108 patients with bacterial meningitis admitted during the study period. Of these, 60 were admitted to the intensive care unit (ICU), and 47 received an intracranial device (only ICP monitoring device N = 16; EVD N = 31). An ICP > 20 mmHg was observed in 8 patients at insertion, and in 21 patients (44%) at any time in the ICU. Cerebrospinal fluid (CSF) was drained in 24 cases (51%). Severe complications (intracranial hemorrhage) related to the device occurred in two patients, but one had a relative contraindication to receiving a device.
CONCLUSIONS: Approximately half of the patients with bacterial meningitis needed intensive care and 47 had an intracranial device inserted. While some had conservatively correctable ICP, the majority needed CSF drainage. However, two patients experienced serious adverse events related to the device, potentially contributing to death. Our study highlights that the incremental value of ICP measurement and EVD in managing of bacterial meningitis requires further research.

UNASSIGNED: Intracranial pressure (ICP)--guided therapy is the standard of care in the management of severe traumatic brain injury (TBI). Ideal ICP monitoring technique is not yet available, based on its risks associated with bleeding, infection, or its unavailability at major centers. Authors propose that ICP can be gauged based on measuring pressures of other anatomical cavities, for example, the abdominal cavity. Researchers explored the possibility of monitoring intra-abdominal pressure (IAP) to predict ICP in severe TBI patients.
UNASSIGNED: We measured ICP and IAP in severe TBI patients. ICP was measured using standard right frontal external ventricular drain (EVD) insertion and connecting it to the transducer. IAP was measured using a well-established technique of vesical pressure measurement through a manometer.
UNASSIGNED: A total of 28 patients (n = 28) with an age range of 18-65 years (mean of 32.36 years ± 13.52 years [Standard deviation]) and the median age of 28.00 years with an interquartile range (21.00-42.00 years) were recruited in this prospective study. About 57.1% (n = 16) of these patients were in the age range of 18-30 years. About 92.9% (n = 26) of the patients were male. The most common mode of injury (78.6%) was road traffic accidents (n = 22) and the mean Glasgow Coma Scale at presentation was 4.04 (range 3-9). The mean ICP measured at the presentation of this patient cohort was 20.04 mmHg. This mean ICP (mmHg) decreased from a maximum of 20.04 at the 0 h\' time point (at the time of insertion of EVD) to a minimum of 12.09 at the 96 hr time point. This change in mean ICP (from 0 h to 96 h) was found to be statistically significant (Friedman Test: χ2 = 87.6, P ≤ 0.001). The mean IAP (cmH2O) decreased from a maximum of 16.71 at the 0 h\' time point to a minimum of 9.68 at the 96 h\' time point. This change was statistically significant (Friedman Test: χ2 = 71.8, P ≤ 0.001). The per unit percentage change in IAP on per unit percentage change in ICP we observed was correlated to each other. The correlation coefficient between these variables varied from 0.71 to 0.89 at different time frames. It followed a trend in a directly proportional manner and was found to be statistically significant (P < 0.001) in each time frame of the study. The rise in one parameter followed the rise in another parameter and vice versa.
UNASSIGNED: In this study, we established that the ICP of severe TBI patients correlates well with IAP at presentation. This correlation was strong and constant, irrespective of the timeframe during the treatment and monitoring. This study also established that draining cerebrospinal fluid to decrease ICP in severe TBI patients is reflected in IAP. The study validates that IAP is a strong proxy of ICP in severe TBI patients.