Extubation in neurocritical care patients: the ENIO international prospective study

Evaluating the Sum of Eye and Motor Components of the Glasgow Coma Score As a Predictor of Extubation Failure in Patients With Acute Brain Injury

OBJECTIVES

To evaluate the association between the pre-extubation sum of eye and motor components of the Glasgow Coma Score (GCS-EM) and odds of extubation failure in patients with acute brain injury being liberated from mechanical ventilation.

DESIGN

Secondary analysis of a prospective, multicenter observational study (ClinicalTrials.gov identifier NCT03400904).

SETTING

Sixty-three hospital sites worldwide, with patient recruitment from January 2018 to November 2020.

PATIENTS

One thousand one hundred fifty-two critically ill patients with acute brain injury, with a median age of 54 years, of whom 783 (68.0%) were male, 559 (48.5%) had traumatic brain injury, and 905 (78.6%) had a GCS-EM greater than 8 before extubation (scores range from 2 to 10).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

GCS-EM was computed in intubated patients on the day of extubation. The main outcome was extubation failure, defined as unplanned reintubation within 5 days of extubation. Analyses used multilevel logistic regression with adjustment for patient characteristics and a random intercept for hospital site. In the primary analysis, GCS-EM was not associated with extubation failure (odds ratio, 1.07 per additional point; 95% CI, 0.87-1.31). Findings were consistent in sensitivity analyses that: 1) used different adjustment covariates, 2) included a verbal estimate to derive an overall GCS, 3) accounted for missing data, 4) considered a 2-day time interval to define extubation failure, 5) accounted for competing risks, and 6) used a propensity score-based model. There was no association between GCS-EM and extubation outcome in subgroups defined by brain injury diagnosis or age.

CONCLUSIONS

In this large, contemporary, multicenter cohort of patients with acute brain injury, we found no association between the GCS-EM and odds of extubation failure. However, few patients had a pre-extubation GCS-EM less than or equal to 8, and the possibility of a true prognostic association in patients with low scores is not excluded.

A nomogram for predicting the necessity of tracheostomy after severe acute brain injury in patients within the neurosurgery intensive care unit: A retrospective cohort study

Objective

This retrospective study was aimed to develop a predictive model for assessing the necessity of tracheostomy (TT) in patients admitted to the neurosurgery intensive care unit (NSICU).

Method

We analyzed data from 1626 NSICU patients with severe acute brain injury (SABI) who were admitted to the Department of NSICU at the Affiliated People's Hospital of Jiangsu University between January 2021 and December 2022. Data of the patients were retrospectively obtained from the clinical research data platform. The patients were randomly divided into training (70%) and testing (30%) cohorts. The least absolute shrinkage and selection operator (LASSO) regression identified the optimal predictive features. A multivariate logistic regression model was then constructed and represented by a nomogram. The efficacy of the model was evaluated based on discrimination, calibration, and clinical utility.

Results

The model highlighted six predictive variables, including the duration of NSICU stay, neurosurgery, orotracheal intubation time, Glasgow Coma Scale (GCS) score, systolic pressure, and respiration rate. Receiver operating characteristic (ROC) analysis of the nomogram yielded area under the curve (AUC) values of 0.854 (95% confidence interval [CI]: 0.822-0.886) for the training cohort and 0.865 (95% CI: 0.817-0.913) for the testing cohort, suggesting commendable differential performance. The predictions closely aligned with actual observations in both cohorts. Decision curve analysis demonstrated that the numerical model offered a favorable net clinical benefit.

Conclusion

We developed a novel predictive model to identify risk factors for TT in SABI patients within the NSICU. This model holds the potential to assist clinicians in making timely surgical decisions concerning TT.

Derivation and validation of a quantitative risk prediction model for weaning and extubation in neurocritical patients

Background

Patients with severe neurological conditions are at high risk during withdrawal and extubation, so it is important to establish a model that can quantitatively predict the risk of this procedure.

Methods

By analyzing the data of patients with traumatic brain injury and tracheal intubation in the ICU of the affiliated hospital of Hangzhou Normal University, a total of 200 patients were included, of which 140 were in the modeling group and 60 were in the validation group. Through binary logistic regression analysis, 8 independent risk factors closely related to the success of extubation were screened out, including age ≥ 65 years old, APACHE II score ≥ 15 points, combined chronic pulmonary disease, GCS score < 8 points, oxygenation index <300, cough reflex, sputum suction frequency, and swallowing function.

Results

Based on these factors, a risk prediction scoring model for extubation was constructed with a critical value of 18 points. The AUC of the model was 0.832, the overall prediction accuracy was 81.5%, the specificity was 81.6%, and the sensitivity was 84.1%. The data of the validation group showed that the AUC of the model was 0.763, the overall prediction accuracy was 79.8%, the specificity was 84.8%, and the sensitivity was 64.0%.

Conclusion

These results suggest that the extubation risk prediction model constructed through quantitative scoring has good predictive accuracy and can provide a scientific basis for clinical practice, helping to assess and predict extubation risk, thereby improving the success rate of extubation and improving patient prognosis.

Incidence and Outcomes of Acute Respiratory Distress Syndrome in Brain-Injured Patients Receiving Invasive Ventilation: A Secondary Analysis of the ENIO Study

Background: Acute respiratory distress syndrome (ARDS) is an important pulmonary complication in brain-injured patients receiving invasive mechanical ventilation (IMV). We aimed to evaluate the incidence and association between ARDS and clinical outcomes in patients with different forms of acute brain injury requiring IMV in the intensive care unit (ICU). Methods: This was a preplanned secondary analysis of a prospective, multicenter, international cohort study (NCT03400904). We included brain-injured patients receiving IMV for ≥ 24 h. ARDS was the main exposure of interest and was identified during index ICU admission using the Berlin definition. We examined the incidence and adjusted association of ARDS with ICU mortality, ICU length of stay, duration of IMV, and extubation failure. Outcomes were evaluated using mixed-effect logistic regression and cause-specific Cox proportional hazards models. Results: 1492 patients from 67 hospitals and 16 countries were included in the analysis, of whom 137 individuals developed ARDS (9.2% of overall cohort). Across countries, the median ARDS incidence was 5.1% (interquartile range [IQR] 0-10; range 0-27.3). ARDS was associated with increased ICU mortality (adjusted odds ratio (OR) 2.66; 95% confidence interval [CI], 1.29-5.48), longer ICU length of stay (adjusted hazard ratio [HR] 0.59; 95% CI, 0.48-0.73), and longer duration of IMV (adjusted HR 0.54; 95% CI, 0.44-0.67). The association between ARDS and extubation failure approached statistical significance (adjusted HR 1.48; 95% CI 0.99-2.21). Higher ARDS severity was associated with incrementally longer ICU length of stay and longer cumulative duration of IMV. Findings remained robust in a sensitivity analysis evaluating the magnitude of unmeasured confounding. Conclusions: In this cohort of acutely brain-injured patients, the incidence of ARDS was similar to that reported in other mixed cohorts of critically ill patients. Development of ARDS was associated with worse outcomes.

Clinical practice and effect of carbon dioxide on outcomes in mechanically ventilated acute brain-injured patients: a secondary analysis of the ENIO study

PURPOSE

The use of arterial partial pressure of carbon dioxide (PaCO2) as a target intervention to manage elevated intracranial pressure (ICP) and its effect on clinical outcomes remain unclear. We aimed to describe targets for PaCO2 in acute brain injured (ABI) patients and assess the occurrence of abnormal PaCO2 values during the first week in the intensive care unit (ICU). The secondary aim was to assess the association of PaCO2 with in-hospital mortality.

METHODS

We carried out a secondary analysis of a multicenter prospective observational study involving adult invasively ventilated patients with traumatic brain injury (TBI), subarachnoid hemorrhage (SAH), intracranial hemorrhage (ICH), or ischemic stroke (IS). PaCO2 was collected on day 1, 3, and 7 from ICU admission. Normocapnia was defined as PaCO2 > 35 and to 45 mmHg; mild hypocapnia as 32-35 mmHg; severe hypocapnia as 26-31 mmHg, forced hypocapnia as < 26 mmHg, and hypercapnia as > 45 mmHg.

RESULTS

1476 patients (65.9% male, mean age 52 ± 18 years) were included. On ICU admission, 804 (54.5%) patients were normocapnic (incidence 1.37 episodes per person/day during ICU stay), and 125 (8.5%) and 334 (22.6%) were mild or severe hypocapnic (0.52 and 0.25 episodes/day). Forced hypocapnia and hypercapnia were used in 40 (2.7%) and 173 (11.7%) patients. PaCO2 had a U-shape relationship with in-hospital mortality with only severe hypocapnia and hypercapnia being associated with increased probability of in-hospital mortality (omnibus p value = 0.0009). Important differences were observed across different subgroups of ABI patients.

CONCLUSIONS

Normocapnia and mild hypocapnia are common in ABI patients and do not affect patients' outcome. Extreme derangements of PaCO2 values were significantly associated with increased in-hospital mortality.

Development of a Prediction Score for Evaluation of Extubation Readiness in Neurosurgical Patients with Mechanical Ventilation

BACKGROUND

There is no widely accepted consensus on the weaning and extubating protocols for neurosurgical patients, leading to heterogeneity in clinical practices and high rates of delayed extubation and extubation failure-related health complications.

METHODS

In this single-center prospective observational diagnostic study, mechanically ventilated neurosurgical patients with extubation attempts were consecutively enrolled for 1 yr. Responsive physicians were surveyed for the reasons for delayed extubation and developed the Swallowing, Tongue protrusion, Airway protection reflected by spontaneous and suctioning cough, and Glasgow Coma Scale Evaluation (STAGE) score to predict the extubation success for neurosurgical patients already meeting other general extubation criteria.

RESULTS

A total of 3,171 patients were screened consecutively, and 226 patients were enrolled in this study. The rates of delayed extubation and extubation failure were 25% (57 of 226) and 19% (43 of 226), respectively. The most common reasons for the extubation delay were weak airway-protecting function and poor consciousness. The area under the receiver operating characteristics curve of the total STAGE score associated with extubation success was 0.72 (95% CI, 0.64 to 0.79). Guided by the highest Youden index, the cutoff point for the STAGE score was set at 6 with 59% (95% CI, 51 to 66%) sensitivity, 74% (95% CI, 59 to 86%) specificity, 90% (95% CI, 84 to 95%) positive predictive value, and 30% (95% CI, 21 to 39%) negative predictive value. At STAGE scores of 9 or higher, the model exhibited a 100% (95% CI, 90 to 100%) specificity and 100% (95% CI, 72 to 100%) positive predictive value for predicting extubation success.

CONCLUSIONS

After a survey of the reasons for delayed extubation, the STAGE scoring system was developed to better predict the extubation success rate. This scoring system has promising potential in predicting extubation readiness and may help clinicians avoid delayed extubation and failed extubation-related health complications in neurosurgical patients.

EDITOR’S PERSPECTIVE

Development of a core outcome set for ventilation trials in neurocritical care patients with acute brain injury: protocol for a Delphi consensus study of international stakeholders

INTRODUCTION

There is little consensus and high heterogeneity on the optimal set of relevant clinical outcomes in research studies regarding extubation in neurocritical care patients with brain injury undergoing mechanical ventilation. The aims of this study are to: (1) develop a core outcome set (COS) and (2) reach consensus on a hierarchical composite endpoint for such studies.

METHODS AND ANALYSIS

The study will include a broadly representative, international panel of stakeholders with research and clinical expertise in this field and will involve four stages: (1) a scoping review to generate an initial list of outcomes represented in the literature, (2) an investigator meeting to review the outcomes for inclusion in the Delphi surveys, (3) four rounds of online Delphi consensus-building surveys and (4) online consensus meetings to finalise the COS and hierarchical composite endpoint.

ETHICS AND DISSEMINATION

This study received ethical approval from the French Society of Anesthesia and Critical Care Medicine Institutional Review Board (SFAR CERAR-IRB 00010254-2023-029). The study results will be disseminated through communication to stakeholders, publication in a peer-reviewed journal, and presentations at conferences.

TRIAL REGISTRATION NUMBER

This study is registered with the Core Outcome Measures in Effectiveness Trials (COMET) Initiative.

Respiratory challenges and ventilatory management in different types of acute brain-injured patients

Acute brain injury (ABI) covers various clinical entities that may require invasive mechanical ventilation (MV) in the intensive care unit (ICU). The goal of MV, which is to protect the lung and the brain from further injury, may be difficult to achieve in the most severe forms of lung or brain injury. This narrative review aims to address the respiratory issues and ventilator management, specific to ABI patients in the ICU.

Brain-lung crosstalk: how should we manage the breathing brain?

Recent studies have drawn increasing attention to brain-lung crosstalk in critically ill patients. However, further research is needed to investigate the pathophysiological interactions between the brain and lungs, establish neuroprotective ventilatory strategies for brain-injured patients, provide guidance on potentially conflicting treatment priorities in patients with concomitant brain and lung injury, and enhance prognostic models to inform extubation and tracheostomy decisions. To bring together such research, BMC Pulmonary Medicine welcomes submissions to its new Collection on 'Brain-lung crosstalk'.

Utilization of mechanical power and associations with clinical outcomes in brain injured patients: a secondary analysis of the extubation strategies in neuro-intensive care unit patients and associations with outcome (ENIO) trial

BACKGROUND

There is insufficient evidence to guide ventilatory targets in acute brain injury (ABI). Recent studies have shown associations between mechanical power (MP) and mortality in critical care populations. We aimed to describe MP in ventilated patients with ABI, and evaluate associations between MP and clinical outcomes.

METHODS

In this preplanned, secondary analysis of a prospective, multi-center, observational cohort study (ENIO, NCT03400904), we included adult patients with ABI (Glasgow Coma Scale ≤ 12 before intubation) who required mechanical ventilation (MV) ≥ 24 h. Using multivariable log binomial regressions, we separately assessed associations between MP on hospital day (HD)1, HD3, HD7 and clinical outcomes: hospital mortality, need for reintubation, tracheostomy placement, and development of acute respiratory distress syndrome (ARDS).

RESULTS

We included 1217 patients (mean age 51.2 years [SD 18.1], 66% male, mean body mass index [BMI] 26.3 [SD 5.18]) hospitalized at 62 intensive care units in 18 countries. Hospital mortality was 11% (n = 139), 44% (n = 536) were extubated by HD7 of which 20% (107/536) required reintubation, 28% (n = 340) underwent tracheostomy placement, and 9% (n = 114) developed ARDS. The median MP on HD1, HD3, and HD7 was 11.9 J/min [IQR 9.2-15.1], 13 J/min [IQR 10-17], and 14 J/min [IQR 11-20], respectively. MP was overall higher in patients with ARDS, especially those with higher ARDS severity. After controlling for same-day pressure of arterial oxygen/fraction of inspired oxygen (P/F ratio), BMI, and neurological severity, MP at HD1, HD3, and HD7 was independently associated with hospital mortality, reintubation and tracheostomy placement. The adjusted relative risk (aRR) was greater at higher MP, and strongest for: mortality on HD1 (compared to the HD1 median MP 11.9 J/min, aRR at 17 J/min was 1.22, 95% CI 1.14-1.30) and HD3 (1.38, 95% CI 1.23-1.53), reintubation on HD1 (1.64; 95% CI 1.57-1.72), and tracheostomy on HD7 (1.53; 95%CI 1.18-1.99). MP was associated with the development of moderate-severe ARDS on HD1 (2.07; 95% CI 1.56-2.78) and HD3 (1.76; 95% CI 1.41-2.22).

CONCLUSIONS

Exposure to high MP during the first week of MV is associated with poor clinical outcomes in ABI, independent of P/F ratio and neurological severity. Potential benefits of optimizing ventilator settings to limit MP warrant further investigation.

Ventilatory targets following brain injury

PURPOSE OF REVIEW

Recent studies have focused on identifying optimal targets and strategies of mechanical ventilation in patients with acute brain injury (ABI). The present review will summarize these findings and provide practical guidance to titrate ventilatory settings at the bedside, with a focus on managing potential brain-lung conflicts.

RECENT FINDINGS

Physiologic studies have elucidated the impact of low tidal volume ventilation and varying levels of positive end expiratory pressure on intracranial pressure and cerebral perfusion. Epidemiologic studies have reported the association of different thresholds of tidal volume, plateau pressure, driving pressure, mechanical power, and arterial oxygen and carbon dioxide concentrations with mortality and neurologic outcomes in patients with ABI. The data collectively make clear that injurious ventilation in this population is associated with worse outcomes; however, optimal ventilatory targets remain poorly defined.

SUMMARY

Although direct data to guide mechanical ventilation in brain-injured patients is accumulating, the current evidence base remains limited. Ventilatory considerations in this population should be extrapolated from high-quality evidence in patients without brain injury - keeping in mind relevant effects on intracranial pressure and cerebral perfusion in patients with ABI and individualizing the chosen strategy to manage brain-lung conflicts where necessary.

Impact of early percutaneous dilatative tracheostomy in patients with subarachnoid hemorrhage on main cerebral, hemodynamic, and respiratory variables: A prospective observational study

Introduction

Patients with poor-grade subarachnoid hemorrhage (SAH) admitted to the intensive care unit (ICU) often require prolonged invasive mechanical ventilation due to prolonged time to obtain neurological recovery. Impairment of consciousness and airway protective mechanisms usually require tracheostomy during the ICU stay to facilitate weaning from sedation, promote neurological assessment, and reduce mechanical ventilation (MV) duration and associated complications. Percutaneous dilatational tracheostomy (PDT) is the technique of choice for performing a tracheostomy. However, it could be associated with particular risks in neurocritical care patients, potentially increasing the risk of secondary brain damage.

Methods

We conducted a single-center, prospective, observational study aimed to assess PDT-associated variations in main cerebral, hemodynamic, and respiratory variables, the occurrence of tracheostomy-related complications, and their relationship with outcomes in adult patients with SAH admitted to the ICU of a neurosurgery/neurocritical care hub center after aneurysm control through clipping or coiling and undergoing early PDT.

Results

We observed a temporary increase in ICP during early PDT; this increase was statistically significant in patients presenting with higher therapy intensity level (TIL) at the time of the procedural. The episodes of intracranial hypertension were brief, and appeared mainly due to the activation of cerebral autoregulatory mechanisms in patients with impaired compensatory mechanisms and compliance.

Discussion

The low number of observed complications might be related to our organizational strategy, all based on a dedicated "tracheo-team" implementing both PDT following a strictly defined protocol and accurate follow-up.

Liberation from Mechanical Ventilation and Tracheostomy Practice in Traumatic Brain Injury

Liberating patients with severe traumatic brain injury (TBI) from mechanical ventilation is often a challenging task. These patients frequently require prolonged ventilation and have persistent alterations in the level and content of consciousness. Questions about their ability to protect their airway are common. Pulmonary complications and copious respiratory secretions are also very prevalent. Thus, it is hardly surprising that rates of extubation failure are high. This is a major problem because extubation failure is associated with a host of poor outcome measures. When the safety of an extubation attempt is uncertain, direct tracheostomy is favored by some, but there is no evidence that this practice leads to better outcomes. Current knowledge is insufficient to reliably predict extubation outcomes in TBI, and practices vary substantially across trauma centers. Yet observational studies provide relevant information that must be weighted when considering the decision to attempt extubation in patients with head injury. This review discusses available evidence on liberation from mechanical ventilation in TBI, proposes priorities for future research, and offers practical advice to guide decisions at the bedside.