Mechanical ventilation in patients with acute ischaemic stroke: from pathophysiology to clinical practice

Prevalence, predictors, and outcomes of acute respiratory distress syndrome in severe stroke

OBJECTIVES

Patients with severe stroke are at high risk of developing acute respiratory distress syndrome (ARDS), but this severe complication was often under-diagnosed and rarely explored in stroke patients. We aimed to investigate the prevalence, early predictors, and outcomes of ARDS in severe stroke.

METHODS

This prospective study included consecutive patients admitted to neurological intensive care unit (neuro-ICU) with severe stroke, including acute ischemic stroke, intracerebral hemorrhage, and subarachnoid hemorrhage. The incidence of ARDS was examined, and baseline characteristics and severity scores on admission were investigated as potential early predictors for ARDS. The in-hospital mortality, length of neuro-ICU stay, the total cost in neuro-ICU, and neurological functions at 90 days were explored.

RESULTS

Of 140 patients included, 35 (25.0%) developed ARDS. Over 90% of ARDS cases occurred within 1 week of admission. Procalcitonin (OR 1.310 95% CI 1.005-1.707, P = 0.046) and PaO2/FiO2 on admission (OR 0.986, 95% CI 0.979-0.993, P < 0.001) were independently associated with ARDS, and high brain natriuretic peptide (OR 0.994, 95% CI 0.989-0.998, P = 0.003) was a red flag biomarker warning that the respiratory symptoms may be caused by cardiac failure rather than ARDS. ARDS patients had longer stays and higher expenses in neuro-ICU. Among patients with ARDS, 25 (62.5%) were moderate or severe ARDS. All the patients with moderate to severe ARDS had an unfavorable outcome at 90 days.

CONCLUSIONS

ARDS is common in patients with severe stroke, with most cases occurring in the first week of admission. Procalcitonin and PaO2/FiO2 on admission are early predictors of ARDS. ARDS worsens both short-term and long-term outcomes. The conflict in respiratory support strategies between ARDS and severe stroke needs to be further studied.

The impact of comorbidities on prolonged mechanical ventilation in patients with chronic obstructive pulmonary disease

BACKGROUND

In patients with chronic obstructive pulmonary disease (COPD) and acute respiratory failure, approximately 10% of them are considered to be at high risk for prolonged mechanical ventilation (PMV, > 21 days). PMV have been identified as independent predictors of unfavorable outcomes. Our previous study revealed that patients aged 70 years older and COPD severity were at a significantly higher risk for PMV. We aimed to analyze the impact of comorbidities and their associated risks in patients with COPD who require PMV.

METHODS

The data used in this study was collected from Kaohsiung Medical University Hospital Research Database. The COPD subjects were the patients first diagnosed COPD (index date) between January 1, 2012 and December 31, 2020. The exclusion criteria were the patients with age less than 40 years, PMV before the index date or incomplete records. COPD and non-COPD patients, matched controls were used by applying the propensity score matching method.

RESULTS

There are 3,744 eligible patients with COPD in the study group. The study group had a rate of 1.6% (60 cases) patients with PMV. The adjusted HR of PMV was 2.21 (95% CI 1.44-3.40; P < 0.001) in the COPD patients than in non-COPD patients. Increased risks of PMV were found significantly for patients with diabetes mellitus (aHR 4.66; P < 0.001), hypertension (aHR 3.20; P = 0.004), dyslipidemia (aHR 3.02; P = 0.015), congestive heart failure (aHR 6.44; P < 0.001), coronary artery disease (aHR 3.11; P = 0.014), stroke (aHR 6.37; P < 0.001), chronic kidney disease (aHR 5.81 P < 0.001) and Dementia (aHR 5.78; P < 0.001).

CONCLUSIONS

Age, gender, and comorbidities were identified as significantly higher risk factors for PMV occurrence in the COPD patients compared to the non-COPD patients. Beyond age, comorbidities also play a crucial role in PMV in COPD.

The Trends of Neutrophil-to-Lymphocyte Ratio, Platelet-to-Lymphocyte Ratio, and Systemic Immunoinflammatory Index in Patients with Intracerebral Hemorrhage and Clinical Value in Predicting Pneumonia 30 Days After Surgery

BACKGROUND

Inflammatory response is closely associated with secondary brain injury and pneumonia in intracerebral hemorrhage (ICH). In this study, we aimed to investigate the value of neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immunoinflammatory index (SII) in the development of pneumonia in ICH patients 30 days after surgery.

METHODS

We retrospectively collected clinical data on patients with ICH who underwent surgical treatment at our institution from January 2016 to December 2022, mainly including NLR, PLR, and SII at different time points. Receiver operating characteristic curves were used to compare the value of different inflammatory indicators in predicting the development of postoperative pneumonia 30 days after surgery in ICH patients, and multivariate logistic regression analyses were used to identify independent risk factors for pneumonia 30 days after surgery.

RESULTS

Among 112 patients with ICH undergoing surgical treatment, 31 (27.7%) developed pneumonia postoperatively. The results of the univariate analysis demonstrated that patients in the pneumonia group experienced significantly higher blood glucose, NLR at 72 hours postoperatively, PLR at 72 hours postoperatively, and SII at 72 hours postoperatively (SII3) than those in the nonpneumonia group, and significantly lower admission Glasgow Coma Scale scores than those in the nonpneumonia group (all P < 0.05). NLR, PLR, and SII showed increasing and then decreasing in the disease process of ICH and peaked at 48 hours postoperatively. Multivariable logistic regression analysis revealed that SII3 was an independent risk factor for postoperative pneumonia 30 days after surgery in ICH patients (odds ratio = 1.001, 95% confidence interval: 1.000-1.002, P = 0.008). The area under the curve of the developed nomogram model was 0.895 (95% confidence interval = 0.823-0.967), with a sensitivity and specificity of 0.903 and 0.815, respectively, providing good predictive power.

CONCLUSIONS

In the course of ICH, NLR, PLR, and SII increased and then decreased and peaked at 48 hours postoperatively. The SII3 was the best predictor of the occurrence of pneumonia postoperatively in ICH patients.

Effects of positive end-expiratory pressure on intracranial pressure, cerebral perfusion pressure, and brain oxygenation in acute brain injury: Friend or foe? A scoping review

Background

Patients with acute brain injury (ABI) are a peculiar population because ABI does not only affect the brain but also other organs such as the lungs, as theorized in brain-lung crosstalk models. ABI patients often require mechanical ventilation (MV) to avoid the complications of impaired respiratory function that can follow ABI; MV should be settled with meticulousness owing to its effects on the intracranial compartment, especially regarding positive end-expiratory pressure (PEEP). This scoping review aimed to (1) describe the physiological basis and mechanisms related to the effects of PEEP in ABI; (2) examine how clinical research is conducted on this topic; (3) identify methods for setting PEEP in ABI; and (4) investigate the impact of the application of PEEP in ABI on the outcome.

Methods

The five-stage paradigm devised by Peters et al. and expanded by Arksey and O'Malley, Levac et al., and the Joanna Briggs Institute was used for methodology. We also adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension criteria. Inclusion criteria: we compiled all scientific data from peer-reviewed journals and studies that discussed the application of PEEP and its impact on intracranial pressure, cerebral perfusion pressure, and brain oxygenation in adult patients with ABI. Exclusion criteria: studies that only examined a pediatric patient group (those under the age of 18), experiments conducted solely on animals; studies without intracranial pressure and/or cerebral perfusion pressure determinations, and studies with incomplete information. Two authors searched and screened for inclusion in papers published up to July 2023 using the PubMed-indexed online database. Data were presented in narrative and tubular form.

Results

The initial search yielded 330 references on the application of PEEP in ABI, of which 36 met our inclusion criteria. PEEP has recognized beneficial effects on gas exchange, but it produces hemodynamic changes that should be predicted to avoid undesired consequences on cerebral blood flow and intracranial pressure. Moreover, the elastic properties of the lungs influence the transmission of the forces applied by MV over the brain so they should be taken into consideration. Currently, there are no specific tools that can predict the effect of PEEP on the brain, but there is an established need for a comprehensive monitoring approach for these patients, acknowledging the etiology of ABI and the measurable variables to personalize MV.

Conclusion

PEEP can be safely used in patients with ABI to improve gas exchange keeping in mind its potentially harmful effects, which can be predicted with adequate monitoring supported by bedside non-invasive neuromonitoring tools.

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.

Short-term mild hyperventilation on intracranial pressure, cerebral autoregulation, and oxygenation in acute brain injury patients: a prospective observational study

Current guidelines suggest a target of partial pressure of carbon dioxide (PaCO2) of 32-35 mmHg (mild hypocapnia) as tier 2 for the management of intracranial hypertension. However, the effects of mild hyperventilation on cerebrovascular dynamics are not completely elucidated. The aim of this study is to evaluate the changes of intracranial pressure (ICP), cerebral autoregulation (measured through pressure reactivity index, PRx), and regional cerebral oxygenation (rSO2) parameters before and after induction of mild hyperventilation. Single center, observational study including patients with acute brain injury (ABI) admitted to the intensive care unit undergoing multimodal neuromonitoring and requiring titration of PaCO2 values to mild hypocapnia as tier 2 for the management of intracranial hypertension. Twenty-five patients were included in this study (40% female), median age 64.7 years (Interquartile Range, IQR = 45.9-73.2). Median Glasgow Coma Scale was 6 (IQR = 3-11). After mild hyperventilation, PaCO2 values decreased (from 42 (39-44) to 34 (32-34) mmHg, p < 0.0001), ICP and PRx significantly decreased (from 25.4 (24.1-26.4) to 17.5 (16-21.2) mmHg, p < 0.0001, and from 0.32 (0.1-0.52) to 0.12 (-0.03-0.23), p < 0.0001). rSO2 was statistically but not clinically significantly reduced (from 60% (56-64) to 59% (54-61), p < 0.0001), but the arterial component of rSO2 (ΔO2Hbi, changes in concentration of oxygenated hemoglobin of the total rSO2) decreased from 3.83 (3-6.2) μM.cm to 1.6 (0.5-3.1) μM.cm, p = 0.0001. Mild hyperventilation can reduce ICP and improve cerebral autoregulation, with minimal clinical effects on cerebral oxygenation. However, the arterial component of rSO2 was importantly reduced. Multimodal neuromonitoring is essential when titrating PaCO2 values for ICP management.

General anesthesia versus nongeneral anesthesia during endovascular therapy for acute ischemic stroke: A systematic review and meta-analysis

OBJECTIVE

This study compares the safety and efficacy of general anesthesia (GA) and nongeneral anesthesia (non-GA) on functional outcomes in patients receiving endovascular therapy for ischemic stroke.

METHODS

All available studies on the anesthetic management of patients with acute ischemic stroke in PubMed, the Cochrane Central Register of Controlled Trials, and Embase were included. We also compared the clinical outcomes in the studies with subgroup analyses of the occlusion site (anterior vs. posterior circulation) and preretriever group versus retriever group. Functional independence, mortality, successful recanalization, hemodynamic instability, intracerebral hemorrhage, and respiratory complications were considered primary or secondary outcomes.

RESULTS

A total of 24,606 patients in 60 studies were included. GA had a lower risk of 90-day functional independence (OR = 0.67, 95% CI 0.58 to 0.77), higher risk of 90-day mortality (OR = 1.29; 95% CI 1.15 to 1.45), and successful reperfusion (OR = 1.18; 95% CI 1.94 to 6.82). However, there were no differences in functional independence and mortality between GA and non-GA at 90 days after the procedure.

CONCLUSION

The study shows poorer results in the GA group, which may be due to the inclusion of nonrandomized studies. However, analysis of the RCTs suggested that the outcomes do not differ between the two groups (GA vs. non-GA). Thus, general anesthesia is as safe as nongeneral anesthesia under standardized management.

From Admission to Discharge: Predicting National Institutes of Health Stroke Scale Progression in Stroke Patients Using Biomarkers and Explainable Machine Learning

As a result of social progress and improved living conditions, which have contributed to a prolonged life expectancy, the prevalence of strokes has increased and has become a significant phenomenon. Despite the available stroke treatment options, patients frequently suffer from significant disability after a stroke. Initial stroke severity is a significant predictor of functional dependence and mortality following an acute stroke. The current study aims to collect and analyze data from the hyperacute and acute phases of stroke, as well as from the medical history of the patients, in order to develop an explainable machine learning model for predicting stroke-related neurological deficits at discharge, as measured by the National Institutes of Health Stroke Scale (NIHSS). More specifically, we approached the data as a binary task problem: improvement of NIHSS progression vs. worsening of NIHSS progression at discharge, using baseline data within the first 72 h. For feature selection, a genetic algorithm was applied. Using various classifiers, we found that the best scores were achieved from the Random Forest (RF) classifier at the 15 most informative biomarkers and parameters for the binary task of the prediction of NIHSS score progression. RF achieved 91.13% accuracy, 91.13% recall, 90.89% precision, 91.00% f1-score, 8.87% FNrate and 4.59% FPrate. Those biomarkers are: age, gender, NIHSS upon admission, intubation, history of hypertension and smoking, the initial diagnosis of hypertension, diabetes, dyslipidemia and atrial fibrillation, high-density lipoprotein (HDL) levels, stroke localization, systolic blood pressure levels, as well as erythrocyte sedimentation rate (ESR) levels upon admission and the onset of respiratory infection. The SHapley Additive exPlanations (SHAP) model interpreted the impact of the selected features on the model output. Our findings suggest that the aforementioned variables may play a significant role in determining stroke patients' NIHSS progression from the time of admission until their discharge.

Preoperative systemic immune-inflammation index may predict prolonged mechanical ventilation in patients with spontaneous basal ganglia intracerebral hemorrhage undergoing surgical operation

Background

Prolonged mechanical ventilation (PMV) has been proven as a risk factor for poor prognosis in patients with neurocritical illness. Spontaneous basal ganglia intracerebral hemorrhage (ICH) is one common subtype of hemorrhagic stroke and is associated with high morbidity and mortality. The systemic immune-inflammation index (SII) is used as a novel and valuable prognostic marker for various neoplastic diseases and other critical illnesses.

Objective

This study aimed to analyze the predictive value of preoperative SII for PMV in patients with spontaneous basal ganglia ICH who underwent surgical operations.

Methods

This retrospective study was conducted in patients with spontaneous basal ganglia ICH who underwent surgical operations between October 2014 and June 2021. SII was calculated using the following formula: SII = platelet count × neutrophil count/lymphocyte count. Multivariate logistic regression analysis and receiver operating characteristics curve (ROC) were used to evaluate the potential risk factors of PMV after spontaneous basal ganglia ICH.

Results

A total of 271 patients were enrolled. Of these, 112 patients (47.6%) presented with PMV. Multivariate logistic regression analysis showed that preoperative GCS (OR, 0.780; 95% CI, 0.688-0.883; P < 0.001), hematoma size (OR, 1.031; 95% CI, 1.016-1.047; P < 0.001), lactic acid (OR, 1.431; 95% CI, 1.015-2.017; P = 0.041) and SII (OR, 1.283; 95% CI, 1.049-1.568; P = 0.015) were significant risk factors for PMV. The area under the ROC curve (AUC) of SII was 0.662 (95% CI, 0.595-0.729, P < 0.001), with a cutoff value was 2,454.51.

Conclusion

Preoperative SII may predict PMV in patients with spontaneous basal ganglia ICH undergoing a surgical operation.

Effect of driving pressure on early postoperative lung gas distribution in supratentorial craniotomy: a randomized controlled trial

BACKGROUND

Neurosurgical patients represent a high-risk population for postoperative pulmonary complications (PPCs). A lower intraoperative driving pressure (DP) is related to a reduction in postoperative pulmonary complications. We hypothesized that driving pressure-guided ventilation during supratentorial craniotomy might lead to a more homogeneous gas distribution in the lung postoperatively.

METHODS

This was a randomized trial conducted between June 2020 and July 2021 at Beijing Tiantan Hospital. Fifty-three patients undergoing supratentorial craniotomy were randomly divided into the titration group or control group at a ratio of 1 to 1. The control group received 5 cmH₂O PEEP, and the titration group received individualized PEEP targeting the lowest DP. The primary outcome was the global inhomogeneity index (GI) immediately after extubation obtained by electrical impedance tomography (EIT). The secondary outcomes were lung ultrasonography scores (LUSs), respiratory system compliance, the ratio of the partial pressure of arterial oxygen to the fraction of inspired oxygen (PaO₂/FiO₂) and PPCs within 3 days postoperatively.

RESULTS

Fifty-one patients were included in the analysis. The median (IQR [range]) DP in the titration group versus the control group was 10 (9-12 [7-13]) cmH₂O vs. 11 (10-12 [7-13]) cmH₂O, respectively (P = 0.040). The GI tract did not differ between groups immediately after extubation (P = 0.080). The LUS_S was significantly lower in the titration group than in the control group immediately after tracheal extubation (1 [0-3] vs. 3 [1-6], P = 0.045). The compliance in the titration group was higher than that in the control group at 1 h after intubation (48 [42-54] vs. 41 [37-46] ml·cmH₂O^-1, P = 0.011) and at the end of surgery (46 [42-51] vs. 41 [37-44] ml·cmH₂O^-1, P = 0.029). The PaO₂/FiO₂ ratio was not significantly different between groups in terms of the ventilation protocol (P = 0.117). At the 3-day follow-up, no postoperative pulmonary complications occurred in either group.

CONCLUSIONS

Driving pressure-guided ventilation during supratentorial craniotomy did not contribute to postoperative homogeneous aeration, but it may lead to improved respiratory compliance and lower lung ultrasonography scores.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov NCT04421976.

Mechanical hyperinflation maneuver and intracranial compliance of critical neurological patients: protocol for a randomized controlled equivalence trial

BACKGROUND

Mechanical hyperinflation maneuver (MHM) is a technique known for optimizing bronchial hygiene and respiratory mechanics; however, its effects on intracranial compliance are not known.

METHODS

Sixty patients aged ≥ 18 years, with clinical diagnosis of acute stroke, confirmed by neuroimaging examination, with onset of symptoms within 72 h, under mechanical ventilation through tracheal tube, will participate in this study. Participants will be randomly allocated into 2 groups: experimental group (n = 30)-MHM plus tracheal aspiration-and control group (n = 30)-tracheal aspiration only. Intracranial compliance will be measured by a non-invasive technique using Brain4care BcMM-R-2000 sensor. This will be the primary outcome. Results will be recorded at 5 times: T0 (start of monitoring), T1 (moment before MHM), T2 (moment after the MHM and before tracheal aspiration), T3 (moment after tracheal aspiration), T4, and T5 (monitoring 10 and 20 min after T3). Secondary outcomes are respiratory mechanics and hemodynamic parameters.

DISCUSSION

This study will be the first clinical trial to examine the effects and safety of MHM on intracranial compliance measured by non-invasive monitoring. Limitation includes the impossibility of blinding the physical therapist who will supervise the interventions. It is expected with this study to demonstrate that MHM can improve respiratory mechanics and hemodynamic parameters and provide a safe intervention with no changes in intracranial compliance in stroke patients.

Tracheostomy timing and outcome in critically ill patients with stroke: a meta-analysis and meta-regression

BACKGROUND

Stroke patients requiring mechanical ventilation often have a poor prognosis. The optimal timing of tracheostomy and its impact on mortality in stroke patients remains uncertain. We performed a systematic review and meta-analysis of tracheostomy timing and its association with reported all-cause overall mortality. Secondary outcomes were the effect of tracheostomy timing on neurological outcome (modified Rankin Scale, mRS), hospital length of stay (LOS), and intensive care unit (ICU) LOS.

METHODS

We searched 5 databases for entries related to acute stroke and tracheostomy from inception to 25 November 2022. We adhered to PRISMA guidance for reporting systematic reviews and meta-analyses. Selected studies included (1) ICU-admitted patients who had stroke (either acute ischaemic stroke, AIS or intracerebral haemorrhage, ICH) and received a tracheostomy (with known timing) during their stay and (2) > 20 tracheotomised. Studies primarily reporting sub-arachnoid haemorrhage (SAH) were excluded. Where this was not possible, adjusted meta-analysis and meta-regression with study-level moderators were performed. Tracheostomy timing was analysed continuously and categorically, where early (< 5 days from initiation of mechanical ventilation to tracheostomy) and late (> 10 days) timing was defined per the protocol of SETPOINT2, the largest and most recent randomised controlled trial on tracheostomy timing in stroke patients.

RESULTS

Thirteen studies involving 17,346 patients (mean age = 59.8 years, female 44%) met the inclusion criteria. ICH, AIS, and SAH comprised 83%, 12%, and 5% of known strokes, respectively. The mean time to tracheostomy was 9.7 days. Overall reported all-cause mortality (adjusted for follow-up) was 15.7%. One in five patients had good neurological outcome (mRS 0-3; median follow-up duration was 180 days). Overall, patients were ventilated for approximately 12 days and had an ICU LOS of 16 days and a hospital LOS of 28 days. A meta-regression analysis using tracheostomy time as a continuous variable showed no statistically significant association between tracheostomy timing and mortality (β = - 0.3, 95% CI = - 2.3 to 1.74, p = 0.8). Early tracheostomy conferred no mortality benefit when compared to late tracheostomy (7.8% vs. 16.4%, p = 0.7). Tracheostomy timing was not associated with secondary outcomes (good neurological outcome, ICU LOS and hospital LOS).

CONCLUSIONS

In this meta-analysis of over 17,000 critically ill stroke patients, the timing of tracheostomy was not associated with mortality, neurological outcomes, or ICU/hospital LOS.

TRIAL REGISTRATION

PROSPERO-CRD42022351732 registered on 17th of August 2022.

Association of Obstructive Sleep Apnea and Atrial Fibrillation in Acute Ischemic Stroke: A Cross-Sectional Study

Background: There is a growing body of evidence suggesting a link between obstructive sleep apnea (OSA) and atrial fibrillation (AF). The primary objective of this study is to evaluate the association between OSA and AF in acute ischemic stroke. The secondary objective is to describe the clinical features of patients with acute ischemic stroke and concomitant OSA. Methods: We enrolled consecutive patients with acute ischemic stroke. All patients underwent full-night cardiorespiratory polygraphy. To determine if there is an association between AF and OSA, we compared the observed frequency of this association with the expected frequency from a random co-occurrence of the two conditions. Subsequently, patients with and without OSA were compared. Results: A total of 174 patients were enrolled (mean age 67.3 ± 11.6 years; 95 males). OSA and AF were present in 89 and 55 patients, respectively. The association OSA + AF was observed in 33/174 cases, which was not statistically different compared to the expected co-occurrence of the two conditions. Patients with OSA showed a higher neck circumference and body mass index, a higher prevalence of hypertension and dysphagia, and a higher number of central apneas/hypoapneas. In the multivariate analysis, dysphagia and hypertension were independent predictors of OSA. A positive correlation was observed between OSA severity, BMI, and neck circumference. The number of central apneas/hypoapneas was positively correlated with stroke severity. Conclusions: Our data suggest that OSA and AF are highly prevalent but not associated in acute stroke. Our findings support the hypothesis that OSA acts as an independent risk factor for stroke.

Palliative care approaches to acute stroke in the hospital setting

Stroke is a prevalent neurologic condition that portends a high risk of morbidity and mortality such that patients impacted by stroke and their caregivers can benefit from palliative care at the time of diagnosis and throughout the disease trajectory. Clinicians who care for stroke patients should be adept at establishing rapport with patients and caregivers, delivering serious news, responding to emotions, discussing prognosis, and establishing goals of care efficiently in an acute stroke setting. Aggressive stroke care can be integrated with a palliative approach to care that involves aligning the available treatment options with a patient's values and goals of care. Reassessing the goals throughout the hospitalization provides an opportunity for continued shared decision-making about the intensity of poststroke interventions. The palliative needs for stroke patients may increase over time depending on the severity of disease, poststroke complications, stroke-related symptoms, and treatment intensity preferences. If the decision is made to transition the focus of care to comfort, the support of an interdisciplinary palliative care or hospice team can be beneficial to the patient, family members, and surrogate decision makers.

Application value and safety of NIPPV combined with routine clearance in the treatment of stroke-associated pneumonia in elderly patients

OBJECTIVE

To investigate the application value and safety of NIPPV (noninvasive positive pressure ventilation) combined with routine clearance in elderly patients with stroke-associated pneumonia (SAP).

METHODS

Altogether 88 elderly SAP patients treated in our hospital from January 2021 to January 2022 were retrospectively evaluated. Among them, 48 cases treated with NIPPV and routine clearance were regarded as an experimental group (EG), and 40 with routine clearance alone were enrolled to a control group (CG). The sputum clearance rate and CPIS score were compared. The safety of NIPPV was evaluated. The clearance treatment cost, hospitalization time and expenses, and the changes of inflammatory factors (IL-6, TNF-α, C-reactive protein (CRP)) were compared before and after treatment. The efficacy of airway clearance after treatment and the risk factors affecting the severity of infection was assessed.

RESULTS

The sputum clearance rate in the EG was higher than that in the CG (P < 0.05). After treatment, the CPIS score of EG was lower (P < 0.05). The hospitalization time and expenses of CG were higher. After treatment, the serum inflammatory factors in CG were higher (P < 0.05), while the clinical efficacy of EG was higher (P < 0.05). Treatment plan, course of disease and diabetes are risk factors for postoperative infection.

CONCLUSION

NIPPV combined with routine clearance is effective for elderly SAP patients, which can shorten the hospitalization time and reduce the expenses.

ARDS associated acute brain injury: from the lung to the brain

A complex interrelation between lung and brain in patients with acute lung injury (ALI) has been established by experimental and clinical studies during the last decades. Although, acute brain injury represents one of the most common insufficiencies in patients with ALI and acute respiratory distress syndrome (ARDS), the underlying pathophysiology of the observed crosstalk remains poorly understood due to its complexity. Specifically, it involves numerous pathophysiological parameters such as hypoxemia, neurological adverse events of lung protective ventilation, hypotension, disruption of the BBB, and neuroinflammation in such a manner that the brain of ARDS patients-especially hippocampus-becomes very vulnerable to develop secondary lung-mediated acute brain injury. A protective ventilator strategy could reduce or even minimize further systemic release of inflammatory mediators and thus maintain brain homeostasis. On the other hand, mechanical ventilation with low tidal volumes may lead to self-inflicted lung injury, hypercapnia and subsequent cerebral vasodilatation, increased cerebral blood flow, and intracranial hypertension. Therefore, by describing the pathophysiology of ARDS-associated acute brain injury we aim to highlight and discuss the possible influence of mechanical ventilation on ALI-associated acute brain injury.

Timely and Appropriate Administration of Inhaled Argon Provides Better Outcomes for tMCAO Mice: A Controlled, Randomized, and Double-Blind Animal Study

BACKGROUND

Inhaled argon (iAr) has shown promising therapeutic efficacy for acute ischemic stroke and has exhibited impressive advantages over other inert gases as a neuroprotective agent. However, the optimal dose, duration, and time point of iAr for acute ischemic stroke are unknown. Here, we explored variable iAr schedules and evaluated the neuroprotective effects of acute iAr administration on lesion volume, brain edema, and neurological function in a mouse model of cerebral ischemic/reperfusion injury.

METHODS

Adult ICR (Institute of Cancer Research) mice were randomly subjected to sham, moderate (1.5 h), or severe (3 h) transient middle cerebral artery occlusion (tMCAO). One hour after tMCAO, the mice were randomized to variable iAr protocols or air. General and focal deficit scores were assessed during double-blind treatment. Infarct volume, overall recovery, and brain edema were analyzed 24 h after cerebral ischemic/reperfusion injury.

RESULTS

Compared with those in the tMCAO-only group, lesion volume (p < 0.0001) and neurologic outcome (general, p < 0.0001; focal, p < 0.0001) were significantly improved in the group administered iAr 1 h after stroke onset (during ischemia). Short-term argon treatment (1 or 3 h) significantly improved the infarct volume (1 vs. 24 h, p < 0.0001; 3 vs. 24 h, p < 0.0001) compared with argon inhalation for 24 h. The concentration of iAr was confirmed to be a key factor in improving focal neurological outcomes relative to that in the tMCAO group, with higher concentrations of iAr showing better effects. Additionally, even though ischemia research has shown an increase in cerebral damage proportional to the ischemia time, argon administration showed significant neuroprotective effects on infarct volume (p < 0.0001), neurological deficits (general, p < 0.0001; focal, p < 0.0001), weight recovery (p < 0.0001), and edema (p < 0.0001) in general, particularly in moderate stroke.

CONCLUSIONS

Timely iAr administration during ischemia showed optimal neurological outcomes and minimal infarct volumes. Moreover, an appropriate duration of argon administration was important for better neuroprotective efficacy. These findings may provide vital guidance for using argon as a neuroprotective agent and moving to clinical trials in acute ischemic stroke.

Necrostatin-1 attenuates Caspase-1-dependent pyroptosis induced by the RIPK1/ZBP1 pathway in ventilator-induced lung injury

BACKGROUND

Ventilator-induced lung injury (VILI) is a complex pathophysiological process leading to acute respiratory distress syndrome (ARDS) and poor outcomes in affected patients. As a form of programmed cell death, pyroptosis is proposed to play an important role in the development of ARDS. Here we investigated whether treating mice with the specific RIPK1 inhibitor Necrostatin-1 (Nec-1) before mechanical ventilation could inhibit pyroptosis and alleviate lung injury in a mouse model.

METHODOLOGYS

Anesthetized C57BL/6J mice received a transtracheal injection of Nec-1 (5 mg/kg) or vehicle (DMSO) 30 min before the experiment which was ventilated for up to 4 h. Lung damage was assessed macroscopically and histologically with oedema measured as the wet/dry ratio of lung tissues. The release of inflammatory mediators into bronchoalveolar lavage fluid (BALF) was assessed by ELISA measurements of TNF-α,interleukin-1β (IL-1β), and IL-6. The expression of RIPK1, ZBP1, caspase-1, and activated (cleaved) caspase-1 were analyzed using western blot and immunohistochemistry, and the levels of gasdermin-D (GSDMD) and IL-1β were analyzed by immunofluorescence staining.

RESULTS

High tidal ventilation produced time-dependent inflammation and lung injury in mice which could be significantly reduced by pretreatment with Nec-1. Notably, Nec-1 reduced the expression of key pyroptosis mediator proteins in lung tissues exposed to mechanical ventilation, including caspase-1, cleaved caspase-1, and GSDMD together with inhibiting the release of inflammatory cytokines.

CONCLUSION

Nec-1 pretreatment alleviates pulmonary inflammatory responses and protects the lung from mechanical ventilation damage. The beneficial effects were mediated at least in part by inhibiting caspase-1-dependent pyroptosis through the RIPK1/ZBP1 pathway.

The Connection Between Selected Caspases Levels in Bronchoalveolar Lavage Fluid and Severity After Brain Injury

Objective

The interaction between the brain and lungs has been the subject of many clinical reports, while the exact impact of brain injury on the physiology of the respiratory system is still subject to numerous experimental studies. The purpose of this study was to investigate the activation of selected caspases levels in bronchoalveolar lavage fluid (mini BALF) of patients after isolated brain injury and their correlation with the severity of the injury.

Methods

The analysis was performed on patients who were admitted to the intensive care unit (ICU) for severe isolated brain injury from March 2018 to April 2020. All patients were intubated and mechanically ventilated. Mini BALF was collected within the first 6–8 h after trauma and on days 3 and 7 after admission. The concentrations of selected caspases were determined and correlated with the severity of brain injury evaluated by the Rotterdam CT Score, Glasgow Coma Score, and 28-day mortality.

Results

Our results showed significantly elevated levels of selected caspases on days 3 and 7 after brain injury, and revealed apoptosis activation during the first 7 days after brain trauma. We found a significant different correlation between the elevation of selected caspases 3, 6, 8, and 9, and the Glasgow Coma Score, Rotterdam CT scale, and 28-day mortality.

Conclusions

The increased levels of selected caspases in the mini BALF in our patients indicate an intensified activation of apoptosis in the lungs, which is related to brain injury itself via various apoptotic pathways and correlates with the severity of brain injury.

Prolonged Mechanical Ventilation: Outcomes and Management

The number of patients requiring prolonged mechanical ventilation (PMV) is increasing worldwide, placing a burden on healthcare systems. Therefore, investigating the pathophysiology, risk factors, and treatment for PMV is crucial. Various underlying comorbidities have been associated with PMV. The pathophysiology of PMV includes the presence of an abnormal respiratory drive or ventilator-induced diaphragm dysfunction. Numerous studies have demonstrated that ventilator-induced diaphragm dysfunction is related to increases in in-hospital deaths, nosocomial pneumonia, oxidative stress, lung tissue hypoxia, ventilator dependence, and costs. Thus far, the pathophysiologic evidence for PMV has been derived from clinical human studies and experimental studies in animals. Moreover, recent studies have demonstrated the outcome benefits of pharmacological agents and rehabilitative programs for patients requiring PMV. However, methodological limitations affected these studies. Controlled prospective studies with an adequate number of participants are necessary to provide evidence of the mechanism, prognosis, and treatment of PMV. The great epidemiologic impact of PMV and the potential development of treatment make this a key research field.

The brain in pediatric critical care: unique aspects of assessment, monitoring, investigations, and follow-up

As survival after pediatric intensive care unit (PICU) admission has improved over recent years, a key focus now is the reduction of morbidities and optimization of quality of life for survivors. Neurologic disorders and direct brain injuries are the reason for 11-16% of admissions to PICU. In addition, many critically ill children are at heightened risk of brain injury and neurodevelopmental difficulties affecting later life, e.g., complex heart disease and premature birth. Hence, assessment, monitoring and protection of the brain, using fundamental principles of neurocritical care, are crucial to the practice of pediatric intensive care medicine. The assessment of brain function, necessary to direct appropriate care, is uniquely challenging amongst children admitted to the PICU. Challenges in assessment arise in children who are unstable, or pharmacologically sedated and muscle relaxed, or who have premorbid abnormality in development. Moreover, the heterogeneity of diseases and ages in PICU patients, means that high caliber evidence is harder to accrue than in adult practice, nonetheless, great progress has been made over recent years. In this 'state of the art' paper about critically ill children, we discuss (1) patient types at risk of brain injury, (2) new standardized clinical assessment tools for age-appropriate, clinical evaluation of brain function, (3) latest evidence related to cranial imaging, non-invasive and invasive monitoring of the brain, (4) the concept of childhood 'post intensive are syndrome' and approaches for neurodevelopmental follow-up. Better understanding of these concepts is vital for taking PICU survivorship to the next level.

Mechanical ventilation induces lung and brain injury through ATP production, P2Y1 receptor activation and dopamine release

Mechanical ventilation can induce lung injury and exacerbate brain injury due to lung-brain interaction. The current study sought to investigate the mechanism of lung-brain interaction induced by mechanical ventilation and offer theoretical insight into the management of ventilator-induced brain injury. The experimental mice were assigned into the spontaneously breathing group and the mechanical ventilation group and injected with dopamine (DA) receptor antagonist haloperidol or P2Y1 receptor antagonist MRS2279 before ventilation. In vitro assay was conducted using lung epithelial cells MLE-12 hippocampal neuron cells and HT-22. Mouse recognition function and lung injury were examined. The condition and concentration of neurons in the hippocampus were observed. The levels of several inflammatory factors, DA, adenosine triphosphate (ATP), P2Y1R, and dysbindin-1 were detected. Mechanical ventilation induced lung and brain injury in mice, manifested in increased inflammatory factors in the bronchoalveolar lavage fluid and hippocampus, prolonged escape latency, and swimming distance and time in the target quadrant with a weakened concentration of neurons in the hippocampus. Our results presented elevated ATP and P2Y1R expressions in the mechanically ventilated mice and stretched MLE-12 cells. The mechanically ventilated mice and P2Y1 receptor activator MRS2365-treated HT-22 cells presented with elevated levels of DA and dysbindin-1. Inactivation of P2Y1 receptor in the hippocampus or blockage of DA receptor alleviated brain injury induced by mechanical ventilation in mice. To conclude, the current study elicited that lung injury induced by mechanical ventilation exacerbated brain injury in mice by increasing ATP production, activating the P2Y1 receptor, and thus promoting DA release.

Noninvasive and invasive mechanical ventilation for neurologic disorders

Patients with acute neurologic injuries frequently require mechanical ventilation due to diminished airway protective reflexes, cardiopulmonary failure secondary to neurologic insults, or to facilitate gas exchange to precise targets. Mechanical ventilation enables tight control of oxygenation and carbon dioxide levels, enabling clinicians to modulate cerebral hemodynamics and intracranial pressure with the goal of minimizing secondary brain injury. In patients with acute spinal cord injuries, neuromuscular conditions, or diseases of the peripheral nerve, mechanical ventilation enables respiratory support under conditions of impending or established respiratory failure. Noninvasive ventilatory approaches may be carefully considered for certain disease conditions, including myasthenia gravis and amyotrophic lateral sclerosis, but may be inappropriate in patients with Guillain-Barré syndrome or when relevant contra-indications exist. With regard to discontinuing mechanical ventilation, considerable uncertainty persists about the best approach to wean patients, how to identify patients ready for extubation, and when to consider primary tracheostomy. Recent consensus guidelines highlight these and other knowledge gaps that are the focus of active research efforts. This chapter outlines important general principles to consider when initiating, titrating, and discontinuing mechanical ventilation in patients with acute neurologic injuries. Important disease-specific considerations are also reviewed where appropriate.

Stroke and breathing

Stroke remains a leading cause of neurologic disability with wide ranging effects, including a variety of respiratory abnormalities. Stroke may influence the central control of the respiratory drive and breathing pattern, airway protection and maintenance, and the respiratory mechanics of inspiration and expiration. In the acute phase of stroke, the central control of breathing is affected by changes in consciousness, cerebral edema, and direct damage to brainstem respiratory centers, resulting in abnormalities in respiratory pattern and loss of airway protection. Common acute complications related to respiratory dysfunction include dysphagia, aspiration, and pneumonia. Respiratory control centers are located in the brainstem, and brainstem stroke causes specific patterns of respiratory dysfunction. Depending on the exact location and extent of stroke, respiratory failure may occur. While major respiratory abnormalities often improve over time, sleep-disordered breathing remains common in the subacute and chronic phases and worsens outcomes. Respiratory mechanics are impaired in hemiplegic or hemiparetic stroke, contributing to worse cardiopulmonary health in stroke survivors. Interventions to address the respiratory complications are under researched, and further investigation in this area is critical to improving outcomes among stroke survivors.

Cerebral Autoregulation in Non-Brain Injured Patients: A Systematic Review

Introduction: Cerebral autoregulation (CA) plays a fundamental role in the maintenance of adequate cerebral blood flow (CBF). CA monitoring, through direct and indirect techniques, may guide an appropriate therapeutic approach aimed at improving CBF and reducing neurological complications; so far, the role of CA has been investigated mainly in brain-injured patients. The aim of this study is to investigate the role of CA in non-brain injured patients.

Methods: A systematic consultation of literature was carried out. Search terms included: “CA and sepsis,” “CA and surgery,” and “CA and non-brain injury.”

Results: Our research individualized 294 studies and after screening, 22 studies were analyzed in this study. Studies were divided in three groups: CA in sepsis and septic shock, CA during surgery, and CA in the pediatric population. Studies in sepsis and intraoperative setting highlighted a relationship between the incidence of sepsis-associated delirium and impaired CA. The most investigated setting in the pediatric population is cardiac surgery, but the role and measurement of CA need to be further elucidated.

Conclusion: In non-brain injured patients, impaired CA may result in cognitive dysfunction, neurological damage, worst outcome, and increased mortality. Monitoring CA might be a useful tool for the bedside optimization and individualization of the clinical management in this group of patients.

Predictive Factors for the Need of Tracheostomy in Patients With Large Vessel Occlusion Stroke Being Treated With Mechanical Thrombectomy

Background: Patients with large vessel occlusion stroke (LVOS) eligible for mechanical thrombectomy (MT) are at risk for stroke- and non-stroke-related complications resulting in the need for tracheostomy (TS). Risk factors for TS have not yet been systematically investigated in this subgroup of stroke patients.

Methods: Prospectively derived data from patients with LVOS and MT being treated in a large, academic neurological ICU (neuro-ICU) between 2014 and 2019 were analyzed in this single-center study. Predictive value of peri- and post-interventional factors, stroke imaging, and pre-stroke medical history were investigated for their potential to predict tracheostomy during ICU stay using logistic regression models.

Results: From 635 LVOS-patients treated with MT, 40 (6.3%) underwent tracheostomy during their neuro-ICU stay. Patients receiving tracheostomy were younger [71 (62–75) vs. 77 (66–83), p < 0.001], had a higher National Institute of Health Stroke Scale (NIHSS) at baseline [18 (15–20) vs. 15 (10–19), p = 0.009] as well as higher rates of hospital acquired pneumonia (HAP) [39 (97.5%) vs. 224 (37.6%), p < 0.001], failed extubation [15 (37.5%) vs. 19 (3.2%), p < 0.001], sepsis [11 (27.5%) vs. 16 (2.7%), p < 0.001], symptomatic intracerebral hemorrhage [5 (12.5%) vs. 22 (3.9%), p = 0.026] and decompressive hemicraniectomy (DH) [19 (51.4%) vs. 21 (3.8%), p < 0.001]. In multivariate logistic regression analysis, HAP (OR 21.26 (CI 2.76–163.56), p = 0.003], Sepsis [OR 5.39 (1.71–16.91), p = 0.004], failed extubation [OR 8.41 (3.09–22.93), p < 0.001] and DH [OR 9.94 (3.92–25.21), p < 0.001] remained as strongest predictors for TS. Patients with longer periods from admission to TS had longer ICU length of stay (r = 0.384, p = 0.03). There was no association between the time from admission to TS and clinical outcome (NIHSS at discharge: r = 0.125, p = 0.461; mRS at 90 days: r = −0.179, p = 0.403).

Conclusions: Patients with LVOS undergoing MT are at high risk to require TS if extubation after the intervention fails, DH is needed, and severe infectious complications occur in the acute phase after ischemic stroke. These factors are likely to be useful for the indication and timing of TS to reduce overall sedation and shorten ICU length of stay.

A best evidence synthesis in practicing early active movements in ICU patients with mechanical ventilation

OBJECTIVE

This study summarized the best evidence of early active movements in mechanically ventilated patients in the ICU and applied it in the intensive care unit of our hospital to evaluate the practical effects.

METHODS

The best evidence for early activity in patients with mechanical ventilation in the ICU was summarized by using an evidence-based nursing method, and the results were clinically applied in the ICU. Patients who were mechanically ventilated in the ICU from January to March 2020 were selected as the control-group, and their counterparts from April to June 2020 were enrolled as the practice-group. The control-group-patients received conventional early active mobilities, and the practice-group-patients performed the best evidence-based early active mobilities. The Barthel index, muscle strength, duration of mechanical ventilation and length of ICU stay between the two groups were compared.

RESULTS

The scores of Barthel index and muscle strength of the practice group were remarkably higher than those of the control group, and the duration of mechanical ventilation and length of ICU stay were obviously shorter than those of the control group, and the difference was statistically significant (P<0.05). The incidence of deep vein thrombosis in practice group was substantially lower than that in control group (P<0.05), and the incidence of ICU acquired weakness in in practice group was critically lower than that in control group (P<0.05). The anxiety and depression scores of the two groups post-intervention were remarkably less than those before intervention (P<0.05), and the observation group had apparently lower scores than the control group (P<0.05).

CONCLUSION

The application of the best evidence of early active movement in ICU patients with mechanical ventilation can improve the daily life ability, promote the recovery of muscle strength, reduce the incidence of deep vein thrombosis and ICU acquired weakness, decrease the duration of mechanical ventilation and length of ICU hospital stay, thereby improving the clinical outcomes.

Brain-lung interactions and mechanical ventilation in patients with isolated brain injury

During the last decade, experimental and clinical studies have demonstrated that isolated acute brain injury (ABI) may cause severe dysfunction of peripheral extracranial organs and systems. Of all potential target organs and systems, the lung appears to be the most vulnerable to damage after brain injury (BI). The pathophysiology of these brain–lung interactions are complex and involve neurogenic pulmonary oedema, inflammation, neurodegeneration, neurotransmitters, immune suppression and dysfunction of the autonomic system. The systemic effects of inflammatory mediators in patients with BI create a systemic inflammatory environment that makes extracranial organs vulnerable to secondary procedures that enhance inflammation, such as mechanical ventilation (MV), surgery and infections. Indeed, previous studies have shown that in the presence of a systemic inflammatory environment, specific neurointensive care interventions—such as MV—may significantly contribute to the development of lung injury, regardless of the underlying mechanisms. Although current knowledge supports protective ventilation in patients with BI, it must be born in mind that ABI-related lung injury has distinct mechanisms that involve complex interactions between the brain and lungs. In this context, the role of extracerebral pathophysiology, especially in the lungs, has often been overlooked, as most physicians focus on intracranial injury and cerebral dysfunction. The present review aims to fill this gap by describing the pathophysiology of complications due to lung injuries in patients with a single ABI, and discusses the possible impact of MV in neurocritical care patients with normal lungs.

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.

Early effects of ventilatory rescue therapies on systemic and cerebral oxygenation in mechanically ventilated COVID-19 patients with acute respiratory distress syndrome: a prospective observational study

BACKGROUND

In COVID-19 patients with acute respiratory distress syndrome (ARDS), the effectiveness of ventilatory rescue strategies remains uncertain, with controversial efficacy on systemic oxygenation and no data available regarding cerebral oxygenation and hemodynamics.

METHODS

This is a prospective observational study conducted at San Martino Policlinico Hospital, Genoa, Italy. We included adult COVID-19 patients who underwent at least one of the following rescue therapies: recruitment maneuvers (RMs), prone positioning (PP), inhaled nitric oxide (iNO), and extracorporeal carbon dioxide (CO2) removal (ECCO2R). Arterial blood gas values (oxygen saturation [SpO2], partial pressure of oxygen [PaO2] and of carbon dioxide [PaCO2]) and cerebral oxygenation (rSO2) were analyzed before (T0) and after (T1) the use of any of the aforementioned rescue therapies. The primary aim was to assess the early effects of different ventilatory rescue therapies on systemic and cerebral oxygenation. The secondary aim was to evaluate the correlation between systemic and cerebral oxygenation in COVID-19 patients.

RESULTS

Forty-five rescue therapies were performed in 22 patients. The median [interquartile range] age of the population was 62 [57-69] years, and 18/22 [82%] were male. After RMs, no significant changes were observed in systemic PaO2 and PaCO2 values, but cerebral oxygenation decreased significantly (52 [51-54]% vs. 49 [47-50]%, p < 0.001). After PP, a significant increase was observed in PaO2 (from 62 [56-71] to 82 [76-87] mmHg, p = 0.005) and rSO2 (from 53 [52-54]% to 60 [59-64]%, p = 0.005). The use of iNO increased PaO2 (from 65 [67-73] to 72 [67-73] mmHg, p = 0.015) and rSO2 (from 53 [51-56]% to 57 [55-59]%, p = 0.007). The use of ECCO2R decreased PaO2 (from 75 [75-79] to 64 [60-70] mmHg, p = 0.009), with reduction of rSO2 values (59 [56-65]% vs. 56 [53-62]%, p = 0.002). In the whole population, a significant relationship was found between SpO2 and rSO2 (R = 0.62, p < 0.001) and between PaO2 and rSO2 (R0 0.54, p < 0.001).

CONCLUSIONS

Rescue therapies exert specific pathophysiological mechanisms, resulting in different effects on systemic and cerebral oxygenation in critically ill COVID-19 patients with ARDS. Cerebral and systemic oxygenation are correlated. The choice of rescue strategy to be adopted should take into account both lung and brain needs. Registration The study protocol was approved by the ethics review board (Comitato Etico Regione Liguria, protocol n. CER Liguria: 23/2020).

Clinical outcomes and prognostic factors for prolonged mechanical ventilation in patients with acute stroke and brain trauma

BACKGROUND/PURPOSE

Neurological dysfunction is a common condition necessitating prolonged mechanical ventilation (PMV). We investigated the clinical features and outcomes of patients with acute neurological diseases requiring PMV.

METHODS

This retrospective observational study was conducted at the Respiratory Care Center (RCC) of Chang Gung Memorial Hospital, Taiwan, between January 2011 and January 2014. The main outcome was weaning success, defined as successful withdrawal from mechanical ventilator support for more than 5 days.

RESULTS

The study included 103 patients with acute stroke and brain trauma receiving PMV. Weaning success was reported in 63 (61%) patients and weaning failure was reported in 40 (39%) patients. Patients in the weaning failure group were older and had a lower RCC Glasgow Coma Scale (GCS) score (6.0 vs 7.9, p = 0.005), lower albumin level (2.8 vs 3.1, p = 0.015), longer RCC stay (28.7 vs 21.3 days, p = 0.017), and higher in-hospital mortality rate (47% vs 9%, p < 0.01). Multivariate analysis revealed that reduced RCC GCS score is an independent prognostic factor for weaning failure (odds ratio [OR] = 1.22, 95% confidence interval [CI] = 1.05-1.46, p = 0.016) and that per unit increase of RCC GCS score is associated with a lower risk of in-hospital mortality (OR = 0.83, 95% CI = 0.70-0.96, p = 0.019).

CONCLUSION

Reduced RCC GCS score is an independent prognostic factor for weaning failure, and is associated with increased in-hospital mortality rates in patients with acute stroke and brain trauma requiring PMV.

Asthma and stroke: a narrative review

Asthma is a heterogeneous disease, usually characterized by chronic airway inflammation, bronchial reversible obstruction and hyperresponsiveness to direct or indirect stimuli. It is a severe disease causing approximately half a million deaths every year and thus possessing a significant public health burden. Stroke is the second leading cause of death and a major cause of disability worldwide. Asthma and asthma medications may be a risk factors for developing stroke. Nevertheless, since asthma is associated with a variety of comorbidities, such as cardiovascular, metabolic and respiratory, the increased incidence of stroke in asthma patients may be due to a confounding effect. The purpose of this review is to analyze the complex relationship between asthma and stroke.

Intensive Care Admission and Management of Patients With Acute Ischemic Stroke: A Cross-sectional Survey of the European Society of Intensive Care Medicine

BACKGROUND

No specific recommendations are available regarding the intensive care management of critically ill acute ischemic stroke (AIS) patients, and questions remain regarding optimal ventilatory, hemodynamic, and general intensive care unit (ICU) therapeutic targets in this population. We performed an international survey to investigate ICU admission criteria and management of AIS patients.

METHODS

An electronic questionnaire including 25 items divided into 3 sections was available on the European Society of Intensive Care Medicine Web site between November 1, 2019 and March 30, 2020 and advertised through the neurointensive care (NIC) section newsletter. This survey was emailed directly to the NIC members and was endorsed by the European Society of Intensive Care Medicine.

RESULTS

There were 214 respondents from 198 centers, with response rate of 16.5% of total membership (214/1296). In most centers (67%), the number of AIS patients admitted to respondents' hospitals in 2019 was between 100 and 300, and, among them, fewer than 50 required ICU admission per hospital. The most widely accepted indication for ICU admission criteria was a requirement for intubation and mechanical ventilation. A standard protocol for arterial blood pressure (ABP) management was utilized by 88 (58%) of the respondents. For patients eligible for intravenous thrombolysis, the most common ABP target was <185/110 mm Hg (n=77 [51%]), whereas for patients undergoing mechanical thrombectomy it was ≤160/90 mm Hg (n=79 [54%]). The preferred drug for reducing ABP was labetalol (n=84 [55.6%]). Other frequently used therapeutic targets included: blood glucose 140 to 180 mg/dL (n=65 [43%]) maintained with intravenous insulin infusion in most institutions (n=110 [72.4%]); enteral feeding initiated within 2 to 3 days from stroke onset (n=142 [93.4%]); oxygen saturation (SpO2) >95% (n=80 [53%]), and tidal volume 6 to 8 mL/kg of predicted body weight (n=135 [89%]).

CONCLUSIONS

The ICU management of AIS, including therapeutic targets and clinical practice strategies, importantly varies between centers. Our findings may be helpful to define future studies and create a research agenda regarding the ICU therapeutic targets for AIS patients.

Critical care management of the patient with an acute ischaemic stroke

Acute ischaemic stroke is a leading cause of morbidity and mortality worldwide. In the UK alone, there are more than 100 000 strokes per year, causing 38 000 deaths. While the incidence remains high, there has been significant medical progress in reducing mortality following a stroke. Admission of patients to specialised stroke units has led to an improvement in clinical outcomes, but the role of intensive care is less well defined. This article reviews the current critical care management and neuro-therapeutic options after an acute ischaemic stroke.

Neuroinflammation, neuronal damage or cognitive impairment associated with mechanical ventilation: A systematic review of evidence from animal studies

PURPOSE

Long-term cognitive impairment is a complication of critical illness survivors. Beside its lifesaving role, mechanical ventilation has potential complications. The aim of this study is to systematically review the evidence collected in animal studies that correlate mechanical ventilation with neuroinflammation, neuronal damage and cognitive impairment.

METHODS

We searched MEDLINE and EMBASE databases for studies published from inception until August 31st, 2020, that enrolled mechanically ventilated animals and reported on neuroinflammation or neuronal damage markers changes or cognitive-behavioural impairment.

RESULTS

Of 5583 studies, 11 met inclusion criteria. Mice, rats, pigs were used. Impact of MV: 4 out of 7 studies reported higher neuroinflammation markers in MV-treated animals and 3 studies reported no differences; 7 out of 8 studies reported a higher neuronal damage and 1 reported no differences; 2 out of 2 studies reported cognitive decline up to 3 days after MV. Higher Tidal volumes are associated with higher changes in brain or serum markers.

CONCLUSION

Preclinical evidence suggests that MV induces neuroinflammation, neuronal damage and cognitive impairment and these are worsened if sub-optimal MV settings are applied. Future studies, with appropriate methodology, are necessary to evaluate for serum monitoring strategies.

TRIAL REGISTRATION NUMBER

CRD42019148935.

Ischaemic stroke-induced distal organ damage: pathophysiology and new therapeutic strategies

Acute ischaemic stroke is associated with a high risk of non-neurological complications, which include respiratory failure, cardiovascular dysfunction, kidney and liver injury, and altered immune and endocrine function. The aim of this manuscript is to provide an overview of the main forms of stroke-induced distal organ damage, providing new pathophysiological insights and recommendations for clinical management.Non-neurological complications of stroke can affect outcomes, with potential for serious short-term and long-term consequences. Many of these complications can be prevented; when prevention is not feasible, early detection and proper management can still be effective in mitigating their adverse impact. The general care of stroke survivors entails not only treatment in the acute setting but also prevention of secondary complications that might hinder functional recovery. Acute ischaemic stroke triggers a cascade of events-including local and systemic activation of the immune system-which results in a number of systemic consequences and, ultimately, may cause organ failure. Understanding the pathophysiology and clinical relevance of non-neurological complications is a crucial component in the proper treatment of patients with acute stroke.Little evidence-based data is available to guide management of these complications. There is a clear need for improved surveillance and specific interventions for the prevention, early diagnosis, and proper management of non-neurological complications during the acute phase of ischaemic stroke, which should reduce morbidity and mortality.

Mechanical ventilation in neurocritical care setting: A clinical approach

Neuropatients often require invasive mechanical ventilation (MV). Ideal ventilator settings and respiratory targets in neuro patients are unclear. Current knowledge suggests maintaining protective tidal volumes of 6-8 ml/kg of predicted body weight in neuropatients. This approach may reduce the rate of pulmonary complications, although it cannot be easily applied in a neuro setting due to the need for special care to minimize the risk of secondary brain damage. Additionally, the weaning process from MV is particularly challenging in these patients who cannot control the brain respiratory patterns and protect airways from aspiration. Indeed, extubation failure in neuropatients is very high, while tracheostomy is needed in one-third of the patients. The aim of this manuscript is to review and describe the current management of invasive MV, weaning, and tracheostomy for the main four subpopulations of neuro patients: traumatic brain injury, acute ischemic stroke, subarachnoid hemorrhage, and intracerebral hemorrhage.

Central Sleep Apnea Predicts Pulmonary Complications After Cardiac Surgery

BACKGROUND

Postoperative major pulmonary complications (MPCs) continue to be leading causes of increased morbidity and death after cardiac surgery. Although various risk factors have been identified, reports on the association between sleep-disordered breathing (SDB) and postoperative MPCs remain inconclusive.

RESEARCH QUESTION

What is the incidence of the composite end point postoperative MPCs? What are predictors for postoperative MPCs in patients without SDB, with OSA, and with central sleep apnea (CSA) who undergo cardiac surgery?

STUDY DESIGN AND METHODS

In this subanalysis of the ongoing prospective observational study "Impact of Sleep-disordered breathing on Atrial Fibrillation and Perioperative complications in Patients undergoing Coronary Artery Bypass grafting Surgery (CONSIDER AF)," preoperative risk factors for postoperative MPCs were examined in 250 patients who underwent cardiac surgery. Postoperative MPCs (including respiratory failure, acute respiratory distress syndrome, pneumonia, or pulmonary embolism) were registered prospectively within the first seven postoperative days. Presence and type of SDB were assessed the night prior to surgery with the use of portable SDB-monitoring.

RESULTS

Patients with SDB experienced significantly more often postoperative MPCs than patients without SDB (24% vs 7%; P < .001). Multivariable logistic regression analysis showed that CSA (OR, 4.68 [95% CI, 1.78-12.26]; P = .002), heart failure (OR, 2.65 [95% CI, 1.11-6.31]; P = .028), and a history of transient ischemic attack or stroke (OR, 2.73 [95% CI, 1.07-6.94]; P = .035) were associated significantly with postoperative MPCs. Compared with patients without MPCs, those with postoperative MPCs had a significantly longer hospital stay (median days, 9 [25th/75th percentile, 7/13] vs 19 [25th/75th percentile, 11/38]; P < .001).

INTERPRETATION

Among established risk factors for postoperative MPCs, CSA, heart failure, and history of transient ischemic attack or stroke were associated significantly with postoperative MPCs. Our findings contribute to the identification of patients who are at high-risk for postoperative MPCs.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT02877745.

Neurological Manifestations of Severe SARS-CoV-2 Infection: Potential Mechanisms and Implications of Individualized Mechanical Ventilation Settings

In December 2019, an outbreak of illness caused by a novel coronavirus (2019-nCoV, subsequently renamed SARS-CoV-2) was reported in Wuhan, China. Coronavirus disease 2019 (COVID-19) quickly spread worldwide to become a pandemic. Typical manifestations of COVID-19 include fever, dry cough, fatigue, and respiratory distress. In addition, both the central and peripheral nervous system can be affected by SARS-CoV-2 infection. These neurological changes may be caused by viral neurotropism, by a hyperinflammatory and hypercoagulative state, or even by mechanical ventilation-associated impairment. Hypoxia, endothelial cell damage, and the different impacts of different ventilatory strategies may all lead to increased stress and strain, potentially exacerbating the inflammatory response and leading to a complex interaction between the lungs and the brain. To date, no studies have taken into consideration the possible secondary effect of mechanical ventilation on brain recovery and outcomes. The aim of our review is to provide an updated overview of the potential pathogenic mechanisms of neurological manifestations in COVID-19, discuss the physiological issues related to brain-lung interactions, and propose strategies for optimization of respiratory support in critically ill patients with SARS-CoV-2 pneumonia.

Intracranial-to-central venous pressure gap predicts the responsiveness of intracranial pressure to PEEP in patients with traumatic brain injury: a prospective cohort study

BACKGROUND

Mechanical ventilation (MV) with positive end-expiratory pressure (PEEP) is commonly applied in patients with severe traumatic brain injury (sTBI). However, the individual responsiveness of intracranial pressure (ICP) to PEEP varies. Thus, identifying an indicator detecting ICP responsiveness to PEEP is of great significance. As central venous pressure (CVP) could act as an intermediary to transduce pressure from PEEP to ICP, we developed a new indicator, P_ICGap, representing the gap between baseline ICP and baseline CVP. The aim of the current study was to explore the relationship between P_ICGap and ICP responsiveness to PEEP.

METHODS

A total of 112 patients with sTBI undergoing MV were enrolled in this prospective cohort study. ICP, CVP, cerebral perfusion pressure (CPP), static compliance of the respiratory system (Cst), and end-tidal carbon dioxide pressure (PetCO₂) were recorded at the initial (3 cmH₂O) and adjusted (15 cmH₂O) levels of PEEP. P_ICGap was assessed as baseline ICP - baseline CVP (when PEEP = 3 cmH₂O). The patients were classified into the ICP responder and non-responder groups based on whether ICP increment with PEEP adjusted from 3 cmH₂O to 15 cmH₂O was greater than 20% of baseline ICP. The above parameters were compared between the two groups, and prediction of ICP responsiveness to PEEP adjustment was evaluated by receiver operating characteristic (ROC) curve analysis.

RESULTS

Compared with the non-responder group, the responder group had lower P_ICGap (1.63 ± 1.33 versus 6.56 ± 2.46 mmHg; p <  0.001), lower baseline ICP, and higher baseline CVP. ROC curve analysis suggested that P_ICGap was a stronger predictive indicator of ICP responsiveness to PEEP (AUC = 0.957, 95%CI 0.918-0.996; p <  0.001) compared with baseline ICP and baseline CVP, with favorable sensitivity (95.24, 95%CI 86.91-98.70%) and specificity (87.6, 95%CI 75.76-94.27%), at a cut off value of 2.5 mmHg.

CONCLUSION

The impact of PEEP on ICP depends on the gap between baseline ICP and baseline CVP, i.e. P_ICGap. In addition, P_ICGap is a potential predictor of ICP responsiveness to PEEP adjustment in patients with sTBI.

Ventilation time and prognosis after stroke thrombectomy: the shorter, the better!

Background and purpose

The aim was to investigate the clinical impact of the duration of artificial ventilation in stroke patients receiving mechanical thrombectomy (MT) under general anaesthesia.

Methods

All consecutive ischaemic stroke patients who had been treated at our centre with MT for anterior circulation large vessel occlusion under general anaesthesia were identified over an 8‐year period. Ventilation time was analysed as a continuous variable and patients were grouped into extubation within 6 h (‘early’), 6–24 h (‘delayed’) and >24 h (‘late’). Favourable outcome was defined as modified Rankin Scale scores of 0–2 at 3 months post‐stroke. Pneumonia rate and reasons for prolonged ventilation were also assessed.

Results

Amongst 447 MT patients (mean age 69.1 ± 13.3 years, 50.1% female), the median ventilation time was 3 h. 188 (42.6%) patients had a favourable 3‐month outcome, which correlated with shorter ventilation time (Spearman’s rho 0.39, P < 0.001). In patients extubated within 24 h, early compared to delayed extubation was associated with improved outcome (odds ratio 2.40, 95% confidence interval 1.53–3.76, P < 0.001). This was confirmed in multivariable analysis (P = 0.01). A longer ventilation time was associated with a higher rate of pneumonia during neurointensive care unit/stroke unit stay (early/delayed/late extubation: 9.6%/20.6%/27.7%, P < 0.01). Whilst stroke‐associated complications represented the most common reasons for late extubation (>24 h), delayed extubation (6–24 h) was associated with admission outside of core working hours (P < 0.001).

Conclusions

Prolonged ventilation time after stroke thrombectomy independently predicts unfavourable outcome at 3 months and is associated with increased pneumonia rates. Therefore, extubation should be performed as early as safely possible.