Aspiration-related acute respiratory distress syndrome in acute stroke patient. PLoS One. 2015;10:e0118682. [PMID: 25790377 PMCID: PMC4366414 DOI: 10.1371/journal.pone.0118682]

AIM2 inflammasome: A potential therapeutic target in ischemic stroke

Ischemic stroke (IS) is a significant global public health issue with a high incidence, disability, and mortality rate. A robust inflammatory cascade with complex and wide-ranging mechanisms occurs following ischemic brain injury. Inflammasomes are multiprotein complexes in the cytoplasm that modulate the inflammatory response by releasing pro-inflammatory cytokines and inducing cellular pyroptosis. Among these inflammasomes, the Absent in Melanoma 2 (AIM2) inflammasome shows the ability to detect a wide range of pathogen DNAs, thereby triggering an inflammatory response. Recent studies have indicated that the aberrant expression of AIM2 inflammasome in various cells is closely associated with the pathological processes of ischemic brain injury. This paper summarizes the expression and regulatory role of AIM2 in CNS and peripheral immune cells and discusses current therapeutic approaches targeting AIM2 inflammasome. These findings aim to serve as a reference for future research in this field.

Mechanical ventilation in acute brain injury patients with acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is commonly seen in patients with acute brain injury (ABI), with prevalence being as high as 35%. These patients often have additional risk factors for ARDS compared to general critical care patients. Lung injury in ABI occurs secondary to catecholamine surge and neuro-inflammatory processes. ARDS patients benefit from lung protective ventilation using low tidal volumes, permissive hypercapnia, high PEEP, and lower PO2 goals. These strategies can often be detrimental in ABI given the risk of brain hypoxia and elevation of intracranial pressure (ICP). While lung protective ventilation is not contraindicated in ABI, special consideration is warranted to make sure it does not interfere with neurological recovery. Permissive hypercapnia with low lung volumes can be utilized in patients without any ICP issues but those with ICP elevations can benefit from continuous ICP monitoring to personalize PCO2 goals. Hypoxia leads to poor outcomes in ABI, hence the ARDSnet protocol of lower PO2 target (55–80 mmHg) might not be the best practice in patients with concomitant ARDS and ABI. High-normal PO2 levels are reasonable in target in severe ABI with ARDS. Studies have shown that PEEP up to 12 mmHg does not cause significant elevations in ICP and is safe to use in ABI though mean arterial pressure, respiratory system compliance, and cerebral perfusion pressure should be closely monitored. Given most trials investigating therapeutics in ARDS have excluded ABI patients, focused research is needed in the field to advance the care of these patients using evidence-based medicine.

Testing oxygenated microbubbles via intraperitoneal and intrathoracic routes on a large pig model of LPS-induced acute respiratory distress syndrome

With a mortality rate of 46% before the onset of COVID-19, acute respiratory distress syndrome (ARDS) affected 200,000 people in the US, causing 75,000 deaths. Mortality rates in COVID-19 ARDS patients are currently at 39%. Extrapulmonary support for ARDS aims to supplement mechanical ventilation by providing life-sustaining oxygen to the patient. A new rapid-onset, human-sized pig ARDS model in a porcine intensive care unit (ICU) was developed. The pigs were nebulized intratracheally with a high dose (4 mg/kg) of the endotoxin lipopolysaccharide (LPS) over a 2 h duration to induce rapid-onset moderate-to-severe ARDS. They were then catheterized to monitor vitals and to evaluate the therapeutic effect of oxygenated microbubble (OMB) therapy delivered by intrathoracic (IT) or intraperitoneal (IP) administration. Post-LPS administration, the PaO2 value dropped below 70 mmHg, the PaO2 /FiO2 ratio dropped below 200 mmHg, and the heart rate increased, indicating rapidly developing (within 4 h) moderate-to-severe ARDS with tachycardia. The SpO2 and PaO2 of these LPS-injured pigs did not show significant improvement after OMB administration, as they did in our previous studies of the therapy on small animal models of ARDS injury. Furthermore, pigs receiving OMB or saline infusions had slightly lower survival than their ARDS counterparts. The OMB administration did not induce a statistically significant or clinically relevant therapeutic effect in this model; instead, both saline and OMB infusion appeared to lower survival rates slightly. This result is significant because it contradicts positive results from our previous small animal studies and places a limit on the efficacy of such treatments for larger animals under more severe respiratory distress. While OMB did not prove efficacious in this rapid-onset ARDS pig model, it may retain potential as a novel therapy for the usual presentation of ARDS in humans, which develops and progresses over days to weeks.

Brain-Lung Crosstalk: Management of Concomitant Severe Acute Brain Injury and Acute Respiratory Distress Syndrome

Purpose of Review

To summarize pathophysiology, key conflicts, and therapeutic approaches in managing concomitant severe acute brain injury (SABI) and acute respiratory distress syndrome (ARDS).

Recent Findings

ARDS is common in SABI and independently associated with worse outcomes in all SABI subtypes. Most landmark ARDS trials excluded patients with SABI, and evidence to guide decisions is limited in this population. Potential areas of conflict in the management of patients with both SABI and ARDS are (1) risk of intracranial pressure (ICP) elevation with high levels of positive end-expiratory pressure (PEEP), permissive hypercapnia due to lung protective ventilation (LPV), or prone ventilation; (2) balancing a conservative fluid management strategy with ensuring adequate cerebral perfusion, particularly in patients with symptomatic vasospasm or impaired cerebrovascular blood flow; and (3) uncertainty about the benefit and harm of corticosteroids in this population, with a mortality benefit in ARDS, increased mortality shown in TBI, and conflicting data in other SABI subtypes. Also, the widely adapted partial pressure of oxygen (P_aO₂) target of > 55 mmHg for ARDS may exacerbate secondary brain injury, and recent guidelines recommend higher goals of 80–120 mmHg in SABI. Distinct pathophysiology and trajectories among different SABI subtypes need to be considered.

Summary

The management of SABI with ARDS is highly complex, and conventional ARDS management strategies may result in increased ICP and decreased cerebral perfusion. A crucial aspect of concurrent management is to recognize the risk of secondary brain injury in the individual patient, monitor with vigilance, and adjust management during critical time windows. The care of these patients requires meticulous attention to oxygenation and ventilation, hemodynamics, temperature management, and the neurological exam. LPV and prone ventilation should be utilized, and supplemented with invasive ICP monitoring if there is concern for cerebral edema and increased ICP. PEEP titration should be deliberate, involving measures of hemodynamic, pulmonary, and brain physiology. Serial volume status assessments should be performed in SABI and ARDS, and fluid management should be individualized based on measures of brain perfusion, the neurological exam, and cardiopulmonary status. More research is needed to define risks and benefits in corticosteroids in this population.

Postoperative acute respiratory dysfunction and the influence of antibiotics after acute type A aortic dissection surgery: A retrospective analysis

OBJECTIVES

Surgery for acute type A aortic dissection is associated with several perioperative complications, such as acute respiratory dysfunction (ARD). The aim of this study was to investigate perioperative risk factors involved in the development of ARD and whether antibiotic treatment has an impact.

METHODS

243 patients underwent surgery for acute type A aortic dissection between 2008 and 2017. The patients were retrospectively divided into the ARD and NON-ARD group. ARD was defined as PaO2/FiO2 ≤ 200 mmHg (PF ratio) within 48 hours after surgery. All patients received either narrow- or broad-spectrum antibiotics.

RESULTS

After the exclusion of 42 patients, 201 patients were analyzed. The PF ratio of the ARD group was significantly lower than of the NON-ARD group within the first 7 days. ARD patients (n = 111) were significantly older (p = .031) and had a higher body mass index (BMI) (p = .017). ARD patients required longer postoperative ventilation (2493 vs. 4695 [min], p = .006) and spent more days in the intensive care unit (7.0 vs. 8.9 [days], p = .043) compared to NON-ARD. The mortality was significantly lower for ARD than for NON-ARD patients (p = .030). The incidence of pneumonia was independent of the antibiotic treatment regime (p = .391). Renal and neurological complication rate was higher in patients treated with broad-spectrum antibiotic.

CONCLUSION

ARD is the main complication (55%) that occurs approximately 24 hours after surgery for acute type A aortic dissection. The preoperative risk factors for ARD were higher age and increased BMI. Patients on broad-spectrum antibiotics did not show an improved postoperative outcome compared to patients with narrow-spectrum antibiotics.

The risk factors for acute respiratory distress syndrome in patients with severe acute pancreatitis: A retrospective analysis

Acute respiratory distress syndrome (ARDS) is very common in patients with severe acute pancreatitis (SAP), the early interventions are essential to the prognosis of SAP patients. We aimed to evaluate the risk factors for ARDS in SAP patients, to provide insights into the management of SAP.SAP patients treated in our hospital from June 1, 2018 to May 31, 2020 were included. The characteristics and lab test results were collected and compared, and we conducted the logistic regression analyses were conducted to identify the potential risk factors for ARDS in patients with SAP.A total of 281 SAP patients were included finally, the incidence of ARDS in patients with SAP was 30.60%. There were significant differences on the respiratory rate, heart rate, APACHE II and Ranson score between 2 groups (all P < .05). And there were significant differences on the polymorphonuclear, procalcitonin, C-reactive protein, serum creatinine, albumin and PO2/FiO2 between 2 groups (all P < .05), and no significant differences on the K+, Na+, Ca+, white blood cell, neutrophils, urine and blood amylase, trypsin, lipase, alanine aminotransferase, aspartate aminotransferase, total bilirubin, triglyceride, total cholesterol, total bilirubin, fasting blood glucose, and pH were found (all P > .05). Respiratory rate >30/min (odds ratio [OR]: 2.405, 95% confidence interval[CI]: 1.163-4.642), APACHE II score >11 (OR: 1.639, 95% CI: 1.078-2.454), Ranson score >5 (OR: 1.473, 95% CI: 1.145-2.359), polymorphonuclear >14 × 109/L (OR: 1.316, 95% CI: 1.073-2.328), C-reactive protein >150 mg/L (OR: 1.127, 95% CI: 1.002-1.534), albumin ≤30 g/L (OR: 1.113, 95% CI: 1.005-1.489) were the independent risk factors for ARDS in patients with SAP (all P < .05).The incidence of ARDS in SAP patients is relatively high, and it is necessary to carry out targeted early prevention and treatment for the above risk factors.

Evaluation of the therapeutic effect of high-flow nasal cannula oxygen therapy on patients with aspiration pneumonia accompanied by respiratory failure in the post-stroke sequelae stage

Background

The aim of the present study was to evaluate the therapeutic effect of high-flow nasal cannula (HFNC) oxygen therapy on patients with aspiration pneumonia accompanied by respiratory failure in the post-stroke sequelae stage, with the goal of providing more effective oxygen therapy and improving patient prognosis.

Methods

Retrospective analysis was conducted on 103 elderly patients with post-stroke aspiration pneumonia and moderate respiratory failure (oxygenation index: 100–200 mmHg) that had been admitted. The patients were divided into two groups according to the mode of oxygen therapy that was used: the Venturi mask group and the HFNC treatment group. The two groups were analyzed and compared in terms of the changes in the blood gas indices measured at different points in time (4, 8, 12, 24, 48, and 72 h), the proportion of patients that required transition to invasive auxiliary ventilation, and the 28-day mortality rate.

Results

A total of 103 patients were retrospectively analyzed; 16 cases were excluded, and 87 patients were included in the final patient group (42 in the HFNC group and 45 in the Venturi group). There was a statistically significant difference in the oxygenation indices of the HFNC group and the Venturi group (F = 546.811, P < 0.05). There was a statistically significant interaction between the monitored oxygenation indices and the mode of oxygen therapy (F = 70.961, P < 0.05), and there was a statistically significant difference in the oxygenation indices for the two modes of oxygen therapy (F = 256.977, P < 0.05). HFNC therapy contributed to the improvement of the oxygenation indices at a rate of 75.1%. The Venturi and HFNC groups also differed significantly in terms of the proportion of patients that required transition to invasive auxiliary ventilation within 72 h (P < 0.05). The HFNC group’s risk for invasive ventilation was 0.406 times that of the Venturi group (P < 0.05). There was no statistical difference in the 28-day mortality rate of the two groups (P > 0.05).

Conclusion

HFNC could significantly improve the oxygenation state of patients with post-stroke aspiration pneumonia and respiratory failure, and it may reduce the incidence of invasive ventilation.

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.

Chronic Obstructive Pulmonary Disease and Stroke

Chronic obstructive pulmonary disease (COPD) is currently the fourth leading cause of death in the world and its incidence and prevalence is on the rise. It is evident that COPD is linked to cardiovascular disease. In the last years, several studies demonstrated that COPD may also be a risk factor for stroke, another major cause of death worldwide. Taking in consideration that COPD has multiple comorbidities it is hard to say whether COPD is an independent risk factor for stroke or it is due to confounding effect. This review is aimed to discuss current data on COPD and stroke, potential links, therapy, and prevention. Current data suggest that COPD may increase the risk of hemorrhagic stroke. The incidence of other stroke subtypes may also be increased in COPD or may be due to confounding effect. However, COPD patients who have stroke are at risk for pulmonary and extrapulmonary complications. We conclude that more studies are needed to further clarify the links between COPD and stroke. The management of COPD as well as the use of prevention therapy is essential to decrease the risk for stroke and should be at special attention in pulmonary medicine and neurology.

Brain-lung crosstalk: Implications for neurocritical care patients

Major pulmonary disorders may occur after brain injuries as ventilator-associated pneumonia, acute respiratory distress syndrome or neurogenic pulmonary edema. They are key points for the management of brain-injured patients because respiratory failure and mechanical ventilation seem to be a risk factor for increased mortality, poor neurological outcome and longer intensive care unit or hospital length of stay. Brain and lung strongly interact via complex pathways from the brain to the lung but also from the lung to the brain. Several hypotheses have been proposed with a particular interest for the recently described “double hit” model. Ventilator setting in brain-injured patients with lung injuries has been poorly studied and intensivists are often fearful to use some parts of protective ventilation in patients with brain injury. This review aims to describe the epidemiology and pathophysiology of lung injuries in brain-injured patients, but also the impact of different modalities of mechanical ventilation on the brain in the context of acute brain injury.