International prospective observational study on intracranial pressure in intensive care (ICU): the SYNAPSE-ICU study protocol

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

BACKGROUND

Numerous trials have addressed intracranial pressure (ICP) management in neurocritical care. However, identifying its harmful thresholds and controlling ICP remain challenging in terms of improving outcomes. Evidence suggests that an individualized approach is necessary for establishing tolerance limits for ICP, incorporating factors such as ICP waveform (ICPW) or pulse morphology along with additional data provided by other invasive (e.g., brain oximetry) and noninvasive monitoring (NIM) methods (e.g., transcranial Doppler, optic nerve sheath diameter ultrasound, and pupillometry). This study aims to assess current ICP monitoring practices among experienced clinicians and explore whether guidelines should incorporate ancillary parameters from NIM and ICPW in future updates.

METHODS

We conducted a survey among experienced professionals involved in researching and managing patients with severe injury across low-middle-income countries (LMICs) and high-income countries (HICs). We sought their insights on ICP monitoring, particularly focusing on the impact of NIM and ICPW in various clinical scenarios.

RESULTS

From October to December 2023, 109 professionals from the Americas and Europe participated in the survey, evenly distributed between LMIC and HIC. When ICP ranged from 22 to 25 mm Hg, 62.3% of respondents were open to considering additional information, such as ICPW and other monitoring techniques, before adjusting therapy intensity levels. Moreover, 77% of respondents were inclined to reassess patients with ICP in the 18-22 mm Hg range, potentially escalating therapy intensity levels with the support of ICPW and NIM. Differences emerged between LMIC and HIC participants, with more LMIC respondents preferring arterial blood pressure transducer leveling at the heart and endorsing the use of NIM techniques and ICPW as ancillary information.

CONCLUSIONS

Experienced clinicians tend to personalize ICP management, emphasizing the importance of considering various monitoring techniques. ICPW and noninvasive techniques, particularly in LMIC settings, warrant further exploration and could potentially enhance individualized patient care. The study suggests updating guidelines to include these additional components for a more personalized approach to ICP management.

Pediatric Traumatic Brain Injury: Impact on the Developing Brain

Traumatic brain injury (TBI) is a serious public health concern impacting millions of children and adolescents each year. Experiencing a brain injury during key critical periods of brain development can affect the normal formation of brain networks that are responsible for a range of complex neurocognitive outcomes. In addition, there are multiple pre- and postinjury factors that influence the trajectory of recovery and outcomes. In this review, we will focus on the current state of the literature within pediatric TBI; systematically review the available research on developmental aspects of TBI in children, focusing on the pathophysiology of the injury and its impact on the developing brain; and highlight knowledge gaps for further exploration.

Intracranial Pressure Monitoring Practice, Treatment, and Effect on Outcome in Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Intracranial pressure (ICP) monitoring and its management in aneurysmal subarachnoid hemorrhage (aSAH) is variable worldwide. The present study aimed to explore the practice of ICP monitoring, its variability across countries, and the association with 6-month outcomes in aSAH.

METHODS

This was a preplanned subanalysis of SYNAPSE-ICU, a multicenter, international, prospective, observational cohort study focused on patients diagnosed with aSAH. We evaluated the variability in ICP monitoring across countries through a logistic regression model adjusted for case-mix and considered countries as a random effect. The association between ICP probe insertion and 6-month mortality and a poor neurological outcome, defined as an Glasgow Outcome Score Extended ≤ 4, was assessed by using a propensity score approach.

RESULTS

A total of 423 patients with aSAH from 92 centers across 32 countries were included in this analysis. ICP monitoring was used in 295 (69.7%) patients. Significant between-country variability in ICP insertion was observed, with an incidence ranging between 4.7% and 79.9% (median odd ratio 3.04). The median duration of ICP monitoring was 12 days (first quartile [Q1] through third quartile [Q3] range 8-18), with an overall daily median ICP value of 14 mm Hg (Q1-Q3 10-19) and a median maximum value of 21 mm Hg (Q1-Q3 16-30). Patients monitored with ICP received more aggressive therapy treatments compared with non-monitored patients (therapy intensity level, TIL, score 10.33 [standard deviation 3.61] vs. 6.3 [standard deviation 4.19], p < 0.001). In more severe patients, ICP monitoring was significantly associated with better 6-month outcome (poor neurological outcome: odds ratio 0.14, 95% confidence interval 0.02-0.53, p = 0.0113; mortality: hazard ratio 0.25, 95% confidence interval 0.13-0.49, p < 0.0001). However, no significant effect was observed in patients with both reactive pupils.

CONCLUSIONS

Our cohort demonstrated high variability in ICP insertion practice among countries. A more aggressive treatment approach was applied in ICP-monitored patients. In patients with severe aSAH, ICP monitoring might reduce unfavorable outcomes and mortality at 6 months.

Treatments for intracranial hypertension in acute brain-injured patients: grading, timing, and association with outcome. Data from the SYNAPSE-ICU study

PURPOSE

Uncertainties remain about the safety and efficacy of therapies for managing intracranial hypertension in acute brain injured (ABI) patients. This study aims to describe the therapeutical approaches used in ABI, with/without intracranial pressure (ICP) monitoring, among different pathologies and across different countries, and their association with six months mortality and neurological outcome.

METHODS

A preplanned subanalysis of the SYNAPSE-ICU study, a multicentre, prospective, international, observational cohort study, describing the ICP treatment, graded according to Therapy Intensity Level (TIL) scale, in patients with ABI during the first week of intensive care unit (ICU) admission.

RESULTS

2320 patients were included in the analysis. The median age was 55 (I-III quartiles = 39-69) years, and 800 (34.5%) were female. During the first week from ICU admission, no-basic TIL was used in 382 (16.5%) patients, mild-moderate in 1643 (70.8%), and extreme in 295 cases (eTIL, 12.7%). Patients who received eTIL were younger (median age 49 (I-III quartiles = 35-62) vs 56 (40-69) years, p < 0.001), with less cardiovascular pre-injury comorbidities (859 (44%) vs 90 (31.4%), p < 0.001), with more episodes of neuroworsening (160 (56.1%) vs 653 (33.3%), p < 0.001), and were more frequently monitored with an ICP device (221 (74.9%) vs 1037 (51.2%), p < 0.001). Considerable variability in the frequency of use and type of eTIL adopted was observed between centres and countries. At six months, patients who received no-basic TIL had an increased risk of mortality (Hazard ratio, HR = 1.612, 95% Confidence Interval, CI = 1.243-2.091, p < 0.001) compared to patients who received eTIL. No difference was observed when comparing mild-moderate TIL with eTIL (HR = 1.017, 95% CI = 0.823-1.257, p = 0.873). No significant association between the use of TIL and neurological outcome was observed.

CONCLUSIONS

During the first week of ICU admission, therapies to control high ICP are frequently used, especially mild-moderate TIL. In selected patients, the use of aggressive strategies can have a beneficial effect on six months mortality but not on neurological outcome.

Intracranial Pressure Monitoring in Patients With Spontaneous Intracerebral Hemorrhage: Insights From the SYNAPSE-ICU Study

BACKGROUND

Uncertainties remain regarding the indications, management, and effect of intracranial pressure (ICP) monitoring and treatment on outcome in spontaneous intracranial hemorrhage (ICH) patients.

METHODS

Analysisof spontaneous ICH patients enrolled in the SYNAPSE-ICU study an international prospective observational study on the use of ICP monitoring. This study aimed to describe, in a large cohort of patients with spontaneous ICH admitted to ICU, the clinical practice of ICP monitoring, the occurrence of intracranial hypertension and its therapeutic management. We further assessed in-hospital mortality and the association between ICP monitoring and 6-months mortality and outcome by a propensity score approach with inverse probability weighting.

RESULTS

587 ICH patients were included in this study; 281 (47.9%) received ICP monitoring. ICP-monitored patients, compared to non-monitored, were younger (61 vs 67 years, p<0.001), presented more frequently with both reactive pupils (67.2%, vs 55.2%, p=0.008), with better neurological status at admission (GCS≤ 8, 82.3% vs 88.8%, p=0.038) and received higher therapy intensity level during ICU stay. In 70.5% (170 out of 241) of ICP monitored patients the ICH score was equal to 3 or 4. Nearly half of monitored patients (46.6%) had at least one episode of ICP ≥ 20 mmHg during the first week. An intraventricular catheter (53.6%) was the most frequently used device and had fewer episodes of intracranial hypertension compared to the other monitoring devices (43.7% vs 64.9%, respectively). At weighted Cox regression model, ICP monitoring was associated with a significant reduction of 6-month mortality (Hazard Ratio, HR= 0.49 (95% Confidence Intervals CI=0.35-0.71, p=0.001), but not with neurological outcome (OR=0.83, 95%CI= 0.41-1.68, p=0.6077).

CONCLUSIONS

ICP monitoring in ICH was utilized mainly in moderately severe cases. ICP monitoring was associated with a reduction of in-hospital and 6-month mortality but did not improve 6-months functional outcomes. Further research and randomized controlled trials to generate higher-level medical evidence to support guidelines regarding ICP use and treatment in patients with ICH are needed.

A scoping review on the challenges, improvement programs, and relevant output metrics for neurotrauma services in major trauma centers

Background:

For a neurotrauma unit to be defined as a structured neurotrauma service (NS) the following criteria must be satisfied: A dedicated neurointensive care unit, endovascular neuroradiology, in-hospital neurorehabilitation unit and helicopter platform within the context of a Level I trauma center. Designing an effective NS can be challenging, particularly when considering the different priorities and resources of countries across the globe. In addition the impact on clinical outcomes is not clearly established.

Methods:

A scoping review of the literature spanning from 2000 to 2020 meant to identify protocols, guidelines, and best practices for the management of traumatic brain injury (TBI) in NS was conducted on the US National Library of Medicine and National Institute of Health databases.

Results:

Limited evidence is available regarding quantitative and qualitative metrics to assess the impact of NSs and specialist follow-up clinics on patients’ outcome. Of note, the available literature used to lack detailed reports for: (a) Geographical clusters, such as low-to-middle income countries (LMIC); (b) clinical subgroups, such as mild TBI; and (c) long-term management, such as rehabilitation services. Only in the last few years more attention has been paid to those research topics.

Conclusion:

NSs can positively impact the management of the broad spectrum of TBI in different clinical settings; however more research on patients’ outcomes and quality of life metrics is needed to establish their efficacy. The collaboration of global clinicians and the development of international guidelines applicable also to LMIC are warranted.

The story of critical care in Asia: a narrative review

Background

Asia has more critically ill people than any other part of our planet. The aim of this article is to review the development of critical care as a specialty, critical care societies and education and research, the epidemiology of critical illness as well as epidemics and pandemics, accessibility and cost and quality of critical care, culture and end-of-life care, and future directions for critical care in Asia.

Main body

Although the first Asian intensive care units (ICUs) surfaced in the 1960s and the 1970s and specialisation started in the 1990s, multiple challenges still exist, including the lack of intensivists, critical care nurses, and respiratory therapists in many countries. This is aggravated by the brain drain of skilled ICU staff to high-income countries. Critical care societies have been integral to the development of the discipline and have increasingly contributed to critical care education, although critical care research is only just starting to take off through collaboration across groups. Sepsis, increasingly aggravated by multidrug resistance, contributes to a significant burden of critical illness, while epidemics and pandemics continue to haunt the continent intermittently. In particular, the coronavirus disease 2019 (COVID-19) has highlighted the central role of critical care in pandemic response. Accessibility to critical care is affected by lack of ICU beds and high costs, and quality of critical care is affected by limited capability for investigations and treatment in low- and middle-income countries. Meanwhile, there are clear cultural differences across countries, with considerable variations in end-of-life care. Demand for critical care will rise across the continent due to ageing populations and rising comorbidity burdens. Even as countries respond by increasing critical care capacity, the critical care community must continue to focus on training for ICU healthcare workers, processes anchored on evidence-based medicine, technology guided by feasibility and impact, research applicable to Asian and local settings, and rallying of governments for support for the specialty.

Conclusions

Critical care in Asia has progressed through the years, but multiple challenges remain. These challenges should be addressed through a collaborative approach across disciplines, ICUs, hospitals, societies, governments, and countries.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40560-021-00574-4.

Multicentre observational study on practice of ventilation in brain injured patients: the VENTIBRAIN study protocol

INTRODUCTION

Mechanical ventilatory is a crucial element of acute brain injured patients' management. The ventilatory goals to ensure lung protection during acute respiratory failure may not be adequate in case of concomitant brain injury. Therefore, there are limited data from which physicians can draw conclusions regarding optimal ventilator management in this setting.

METHODS AND ANALYSIS

This is an international multicentre prospective observational cohort study. The aim of the 'multicentre observational study on practice of ventilation in brain injured patients'-the VENTIBRAIN study-is to describe the current practice of ventilator settings and mechanical ventilation in acute brain injured patients. Secondary objectives include the description of ventilator settings among different countries, and their association with outcomes. Inclusion criteria will be adult patients admitted to the intensive care unit (ICU) with a diagnosis of traumatic brain injury or cerebrovascular diseases (intracranial haemorrhage, subarachnoid haemorrhage, ischaemic stroke), requiring intubation and mechanical ventilation and admission to the ICU. Exclusion criteria will be the following: patients aged <18 years; pregnant patients; patients not intubated or not mechanically ventilated or receiving only non-invasive ventilation. Data related to clinical examination, neuromonitoring if available, ventilator settings and arterial blood gases will be recorded at admission and daily for the first 7 days and then at day 10 and 14. The Glasgow Outcome Scale Extended on mortality and neurological outcome will be collected at discharge from ICU, hospital and at 6 months follow-up.

ETHICS AND DISSEMINATION

The study has been approved by the Ethic committee of Brianza at the Azienda Socio Sanitaria Territoriale-Monza. Data will be disseminated to the scientific community by abstracts submitted to the European Society of Intensive Care Medicine annual conference and by original articles submitted to peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT04459884.

Intracranial pressure monitoring in patients with acute brain injury in the intensive care unit (SYNAPSE-ICU): an international, prospective observational cohort study

BACKGROUND

The indications for intracranial pressure (ICP) monitoring in patients with acute brain injury and the effects of ICP on patients' outcomes are uncertain. The aims of this study were to describe current ICP monitoring practises for patients with acute brain injury at centres around the world and to assess variations in indications for ICP monitoring and interventions, and their association with long-term patient outcomes.

METHODS

We did a prospective, observational cohort study at 146 intensive care units (ICUs) in 42 countries. We assessed for eligibility all patients aged 18 years or older who were admitted to the ICU with either acute brain injury due to primary haemorrhagic stroke (including intracranial haemorrhage or subarachnoid haemorrhage) or traumatic brain injury. We included patients with altered levels of consciousness at ICU admission or within the first 48 h after the brain injury, as defined by the Glasgow Coma Scale (GCS) eye response score of 1 (no eye opening) and a GCS motor response score of at least 5 (not obeying commands). Patients not admitted to the ICU or with other forms of acute brain injury were excluded from the study. Between-centre differences in use of ICP monitoring were quantified by using the median odds ratio (MOR). We used the therapy intensity level (TIL) to quantify practice variations in ICP interventions. Primary endpoints were 6 month mortality and 6 month Glasgow Outcome Scale Extended (GOSE) score. A propensity score method with inverse probability of treatment weighting was used to estimate the association between use of ICP monitoring and these 6 month outcomes, independently of measured baseline covariates. This study is registered with ClinicalTrial.gov, NCT03257904.

FINDINGS

Between March 15, 2018, and April 30, 2019, 4776 patients were assessed for eligibility and 2395 patients were included in the study, including 1287 (54%) with traumatic brain injury, 587 (25%) with intracranial haemorrhage, and 521 (22%) with subarachnoid haemorrhage. The median age of patients was 55 years (IQR 39-69) and 1567 (65%) patients were male. Considerable variability was recorded in the use of ICP monitoring across centres (MOR 4·5, 95% CI 3·8-4·9 between two randomly selected centres for patients with similar covariates). 6 month mortality was lower in patients who had ICP monitoring (441/1318 [34%]) than in those who were not monitored (517/1049 [49%]; p<0·0001). ICP monitoring was associated with significantly lower 6 month mortality in patients with at least one unreactive pupil (hazard ratio [HR] 0·35, 95% CI 0·26-0·47; p<0·0001), and better neurological outcome at 6 months (odds ratio 0·38, 95% CI 0·26-0·56; p=0·0025). Median TIL was higher in patients with ICP monitoring (9 [IQR 7-12]) than in those who were not monitored (5 [3-8]; p<0·0001) and an increment of one point in TIL was associated with a reduction in mortality (HR 0·94, 95% CI 0·91-0·98; p=0·0011).

INTERPRETATION

The use of ICP monitoring and ICP management varies greatly across centres and countries. The use of ICP monitoring might be associated with a more intensive therapeutic approach and with lower 6-month mortality in more severe cases. Intracranial hypertension treatment guided by monitoring might be considered in severe cases due to the potential associated improvement in long-term clinical results.

FUNDING

University of Milano-Bicocca and the European Society of Intensive Care Medicine.

Monitoring and Measurement of Intracranial Pressure in Pediatric Head Trauma

Purpose of Review: Monitoring of intracranial pressure (ICP) is an important and integrated part of the treatment algorithm for children with severe traumatic brain injury (TBI). Guidelines often recommend ICP monitoring with a treatment threshold of 20 mmHg. This focused review discusses; (1) different ICP technologies and how ICP should be monitored in pediatric patients with severe TBI, (2) existing evidence behind guideline recommendations, and (3) how we could move forward to increase knowledge about normal ICP in children to support treatment decisions.

Summary: Current reference values for normal ICP in adults lie between 7 and 15 mmHg. Recent studies conducted in “pseudonormal” adults, however, suggest a normal range below this level where ICP is highly dependent on body posture and decreases to negative values in sitting and standing position. Despite obvious physiological differences between children and adults, no age or body size related reference values exist for normal ICP in children. Recent guidelines for treatment of severe TBI in pediatric patients recommend ICP monitoring to guide treatment of intracranial hypertension. Decision on ICP monitoring modalities are based on local standards, the individual case, and the clinician's choice. The recommended treatment threshold is 20 mmHg for a duration of 5 min. Both prospective and retrospective observational studies applying different thresholds and treatment strategies for intracranial hypertension were included to support this recommendation. While some studies suggest improved outcome related to ICP monitoring (lower rate of mortality and severe disability), most studies identify high ICP as a marker of worse outcome. Only one study applied age-differentiated thresholds, but this study did not evaluate the effect of these different thresholds on outcome. The quality of evidence behind ICP monitoring and treatment thresholds in severe pediatric TBI is low and treatment can potentially be improved by knowledge about normal ICP from observational studies in healthy children and cohorts of pediatric “pseudonormal” patients expected to have normal ICP. Acceptable levels of ICP − and thus also treatment thresholds—probably vary with age, disease and whether the patient has intact cerebral autoregulation. Future treatment algorithms should reflect these differences and be more personalized and dynamic.