Ventilation-induced jet suggests biotrauma in reconstructed airways of the intubated neonate.


  • 影响因子:3.67
  • DOI:10.1098/rsif.2019.0516
  • 作者列表:"Nof E","Heller-Algazi M","Coletti F","Waisman D","Sznitman J
  • 发表时间:2020-01-01

:We investigate respiratory flow phenomena in a reconstructed upper airway model of an intubated neonate undergoing invasive mechanical ventilation, spanning conventional to high-frequency ventilation (HFV) modes. Using high-speed tomographic particle image velocimetry, we resolve transient, three-dimensional flow fields and observe a persistent jet flow exiting the endotracheal tube whose strength is directly modulated according to the ventilation protocol. We identify this synthetic jet as the dominating signature of convective flow under intubated ventilation. Concurrently, our in silico wall shear stress analysis reveals a hitherto overlooked source of ventilator-induced lung injury as a result of jet impingement on the tracheal carina, suggesting damage to the bronchial epithelium; this type of injury is known as biotrauma. We find HFV advantageous in mitigating the intensity of such impingement, which may contribute to its role as a lung protective method. Our findings may encourage the adoption of less invasive ventilation procedures currently used in neonatal intensive care units.


: 我们研究了接受有创机械通气的插管新生儿重建上气道模型中的呼吸流动现象,跨越常规到高频通气 (HFV) 模式。利用高速层析粒子图像测速技术,我们解析了瞬态、三维流场,并观察到从气管内管流出的持续射流,其强度根据通气方案直接调制。我们将这种合成射流确定为插管通气下对流流动的主要特征。同时,我们的计算机壁剪切应力分析揭示了由于射流撞击气管隆突而导致的呼吸机诱发肺损伤的一个迄今被忽视的来源,提示支气管上皮受损; 这种类型的损伤被称为生物创伤。我们发现 HFV 有利于减轻这种撞击的强度,这可能有助于其作为肺保护方法的作用。我们的研究结果可能会鼓励采用目前新生儿重症监护病房使用的无创通气程序。



作者列表:["Maria Kózka","Aurelia Sega","Katarzyna Wojnar-Gruszka","Agnieszka Tarnawska","Agnieszka Gniadek"]

METHODS:Background: The hospitalization of patients treated in the intensive care unit (ICU) in 5&#8722;15% of cases is associated with the occurrence of a complication in the form of ventilator-associated pneumonia (VAP). Purpose: Retrospective assessment of risk factors of VAP in patients treated at ICUs in the University Hospital in Krakow. Methods: The research involved the medical documentation of 1872 patients treated at the ICU of the University Hospital in Krakow between 2014 and 2017. The patients were mechanically ventilated for at least 48 h. The obtained data were presented by qualitative and quantitative analysis (%). The qualitative variables were compared using the Chi2 test. Statistically significant was the p < 0.05 value. Results: VAP was demonstrated in 23% of all patients treated in ICU during the analyzed period, and this infection occurred in 13% of men and 10% of women. Pneumonia associated with ventilation was found primarily in patients staying in the ward for over 15 days and subjected to intratracheal intubation (17%). A statistically significant was found between VAP and co-morbidities, e.g., chronic obstructive pulmonary disease, diabetes, alcoholism, obesity, the occurrence of VAP and multi-organ trauma, hemorrhage/hemorrhagic shock, and fractures as the reasons for admitting ICU patients. Conclusions: Patients with comorbidities such as chronic obstructive pulmonary disease, obesity, diabetes, and alcoholism are a high-risk group for VAP. Particular attention should be paid to patients admitted to the ICU with multi-organ trauma, fractures, and hemorrhage/hemorrhagic shock as patients predisposed to VAP. There is a need for further research into risk factors for non-modifiable VAP such as comorbidities and reasons for ICU admission in order to allow closer monitoring of these patients for VAP.

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来源期刊:Bioscience reports
作者列表:["Yu H","Luo J","Ni Y","Hu Y","Liu D","Wang M","Liang B","Liang Z"]

METHODS::Backgroud Severe pneumonia is one of the most common causes for mechanical ventilation. We aimed to early identify severe pneumonia patients with high risk of extubation failure in order to improve prognosis. Methods From April 2014 to December 2015, medical records of intubated patients with severe pneumonia in intensive care unit were retrieved from database. Patients were divided into extubation success and failure groups, and multivariate logistic regressions were performed to identify independent predictors for extubation failure. Results A total of 125 eligible patients were included, of which 82 and 43 patients had extubation success and failure, respectively. APACHE II score (odds ration (OR) 1.141, 95% confident interval (CI) 1.022-1.273, P = 0.019, cutoff at 17.5), blood glucose (OR 1.122, 95%CI 1.008-1.249, P = 0.035, cutoff at 9.87mmol/L), dose of fentanyl (OR 3.010, 95%CI 1.100-8.237, P = 0.032, cutoff at 1.135mg/d), and the need for red blood cell (RBC) transfusion (OR 2.774, 95%CI 1.062-7.252, P = 0.037) were independent risk factors for extubation failure. Conclusions In patients with severe pneumonia, APACHE II score > 17.5, blood glucose > 9.87mmol/L, fentanyl usage > 1.135mg/d, and the need for RBC transfusion might be associated with higher risk of extubation failure.

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作者列表:["Lundin A","Karlsson T","Herlitz J","Lundgren P","Rylander C"]

METHODS:PURPOSE:To assess the association between the duration of mechanical ventilation during post resuscitation care and 30-day survival after cardiac arrest. METHODS:We conducted a retrospective observational study using data from two national registries. Comatose cardiac arrest patients admitted to general intensive care in Swedish hospitals between 2011 and 2016 were eligible. Based on the median duration of mechanical ventilation for patients who did not survive to hospital discharge, used as a proxy for the endurance of post resuscitation care, the hospitals were divided into four ordered groups for which association with 30-day survival was analyzed. RESULTS:In total, 5.113 patients in 56 hospitals were included. Median duration of mechanical ventilation for patients who did not survive to hospital discharge ranged from 17 hours in hospital group 1 to 51 hours in hospital group 4. After adjustment for baseline characteristics, 30-day survival in the entire cohort was positively and independently associated with ordered hospital group: (adjusted odds ratio (95%CI); 1.12 (1.02,1.23); p = 0.02). Thus, hospitals with a longer duration of mechanical ventilation among non-survivors had better survival rate among patients admitted to ICU after a cardiac arrest. However, in a secondary analysis restricted to patients with length of stay in the intensive care unit ≥ 48 hours, there was no significant association between 30-day survival and ordered hospital group. CONCLUSION:A tendency for longer duration of post resuscitation care in the ICU was associated with higher 30-day survival in comatose patients admitted to intensive care after cardiac arrest.

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