Acute lung injury and acute respiratory distress syndrome in sepsis and septic shock

Sepsis remains the leading cause of ARDS, and ARDS is still an often fatal condition. With our expanding knowledge of the pathobiologic mechanisms and the relationship between these two entities, early recognition, treatment, and prevention of sepsis may prevent or hasten recovery from ARDS. Understanding the biologic markers involved in the complex inflammatory response of sepsis and acute lung injury offers the possibility of future investigations to target treatment based on these mediators.     

肺部超声在体外膜肺氧合挽救儿童急性呼吸窘迫综合征中的价值

目的:评价肺部超声在体外膜肺氧合（extracorporeal membrane oxygenation,ECMO）治疗重度急性呼吸窘迫综合征（acute respiratory distress syndrome,ARDS）患儿肺部病情评估中的价值。方法:采用前瞻性研究的方法,纳入2016年1月至2019年12月期间在上海交通大学附属儿童医院重症医学科符合柏林标准的重度ARDS患儿,排除ECMO治疗时间<3 d、缺乏合适声窗、严重气胸及继发于先天性心脏病或慢性肺部疾病的患儿。采用肺部超声评估ECMO挽救患儿的肺部病变资料,包括ECMO启动时、ECMO治疗后24 h、48 h、72 h、第7天及撤机时动态肺部超声评分（lung ultrasound score,LUS）,分别记录为LUS-0 h、LUS-24 h、LUS-48 h、LUS-72 h,LUS-7 d,LUS-w。根据出院时生存状态分为死亡组及存活组,采用受试者工作特征（receiver operating characteristic,ROC）曲线及Kaplan-Meier生存分析曲线分析LUS与预后的关系。结果:研究共纳入26例患儿,其中18例存活,8例死亡。ECMO启动时,第三代小儿死亡危险评分、肺动态顺应性（pulmonary dynamic compliance,Cdyn）、氧合指数、动脉血氧分压/吸入氧体积分数、二氧化碳分压等两组之间均差异无统计学意义（ P>0.05）。死亡组LUS-72 h和LUS-w明显高于存活组[26（24,29） vs 16（13,19）, P<0.01]和[30（26,35） vs 11（10,13）, P<0.01]。存活组Cdyn-72 h、Cdyn-7 d和Cdyn-w明显高于死亡组[0.48（0.42,0.54）mL/cmH 2O·kg vs 0.36（0.29,0.40） mL/cmH 2O·kg, P<0.01]、[0.60（0.52,0.67）mL/cmH 2O·kg vs 0.27（0.13,0.30） mL/cmH 2O·kg, P<0.01;0.66（0.62,0.70）mL/cmH 2O·kg vs 0.30（0.13,0.35） mL/cmH 2O·kg, P<0.01]。ROC曲线分析显示LUS-72 h预测患儿生存状态的AUC为0.955（95% CI：0.864~1.000, P<0.01）;截断值为24时灵敏度为87.5%,特异度为100.0%。以LUS-72 h≥24和LUS-72 h<24分组进行Kaplan-Meier生存分析：LUS-72 h≥24组病死率显著高于LUS-72 h<24组（ P<0.01）。 结论:肺部超声LUS测定对ECMO挽救ARDS患儿病情和预后判断具有参考价值。     

Effect of low doses of corticosteroids in septic shock patients with or without early acute respiratory distress syndrome

OBJECTIVE: We investigated the efficacy of low doses of corticosteroids in septic shock patients with or without early acute respiratory distress syndrome (ARDS) by post hoc analysis of a previously completed clinical trial. DESIGN: Retrospective analysis of a placebo-controlled, randomized, double-blind trial of low doses of corticosteroids in septic shock. SETTING: Nineteen intensive care units in France. PATIENTS: Among the 300 septic shock patients enrolled, we selected those meeting standard criteria for ARDS at inclusion. INTERVENTIONS: Seven-day treatment with 50 mg of hydrocortisone every 6 hrs and 50 microg of 9-alpha-fludrocortisone once a day. MEASUREMENTS AND MAIN RESULTS: There were 177 patients with ARDS (placebo, n = 92; corticosteroids, n = 85) including 129 (placebo, n = 67; corticosteroids, n = 62) nonresponders and 48 (placebo, n = 25; corticosteroids, n = 23) responders. In nonresponders, there were 50 deaths (75%) in the placebo group and 33 deaths (53%) in the steroid group (hazard ratio 0.57, 95% confidence interval 0.36-0.89, p = .013; relative risk 0.71, 95% confidence interval 0.54-0.94, p = .011). The number of days alive and off the ventilator was 2.6 +/- 6.6 in the placebo group and 5.7 +/- 8.6 in the steroid group (p = .006). There was no significant difference between groups in responders. There was no significant difference between groups in the two subsets of patients without ARDS. Adverse events rates were similar in the two groups. CONCLUSIONS: This post hoc analysis shows that a 7-day treatment with low doses of corticosteroids was associated with better outcomes in septic shock-associated early ARDS nonresponders, but not in responders and not in septic shock patients without ARDS.     

Lung ultrasound in acute respiratory distress syndrome and acute lung injury

PURPOSE OF REVIEW: Lung ultrasound at the bedside can provide accurate information on lung status in critically ill patients with acute respiratory distress syndrome. RECENT FINDINGS: Lung ultrasound can replace bedside chest radiography and lung computed tomography for assessment of pleural effusion, pneumothorax, alveolar-interstitial syndrome, lung consolidation, pulmonary abscess and lung recruitment/de-recruitment. It can also accurately determine the type of lung morphology at the bedside (focal or diffuse aeration loss), and therefore it is useful for optimizing positive end-expiratory pressure. The learning curve is brief, so most intensive care physicians will be able to use it after a few weeks of training. SUMMARY: Lung ultrasound is noninvasive, easily repeatable and allows assessment of changes in lung aeration induced by the various therapies. It is among the most promising bedside techniques for monitoring patients with acute respiratory distress syndrome.     

Early adaptive immune suppression in children with septic shock: a prospective observational study

Introduction

Innate immune suppression occurs commonly in pediatric critical illness, in which it is associated with adverse outcomes. Less is known about the adaptive immune response in critically ill children with sepsis. We designed a single-center prospective, observational study to test the hypothesis that children with septic shock would have decreased adaptive immune function compared with healthy children and that among children with sepsis, lower adaptive immune function would be associated with the development of persistent infection or new nosocomial infection.

Methods

Children (18 years or younger) who were admitted to the pediatric intensive care unit with septic shock (by International Consensus Criteria) were enrolled in the study. Blood samples were taken within 48 hours of sepsis onset and again on Day 7 of illness. Adaptive immune function was assessed with ex vivo phytohemagglutinin (PHA)-induced cytokine production capacity of isolated CD4⁺ T cells. Percentage of regulatory T cells was measured with flow cytometry. Absolute lymphocyte counts were recorded when available.

Results

In total, 22 children with septic shock and eight healthy controls were enrolled. Compared with those from healthy children, CD4⁺ T cells isolated from septic shock children on Days 1 to 2 of illness and stimulated with PHA produced less of the pro-inflammatory cytokine interferon gamma (IFN-γ) (P = 0.002), and the antiinflammatory cytokines interleukin (IL)-4 (P = 0.03) and IL-10 (P = 0.02). Among septic shock children, those who went on to develop persistent or nosocomial infection had decreased T-cell ex vivo PHA-induced production of IFN-γ (P = 0.01), IL-2 (P = 0.01), IL-4 (P = 0.008), and IL-10 (P = 0.001) compared with septic shock children who did not. Percentage of regulatory T cells (CD4⁺CD25⁺CD127^lo) did not differ among groups.

Conclusions

Adaptive immune suppression may occur early in the course of pediatric septic shock and is associated with adverse infection-related outcomes.     

维生素D对脓毒性休克导致急性呼吸窘迫综合征患者的干预价值研究

目的探索维生素D对脓毒性休克致急性呼吸窘迫综合征（ARDS）的干预效果。 方法选取2017年6月至2019年6月入住山西医科大学第一医院重症监护室发生脓毒性休克导致ARDS的80例患者，根据25-羟维生素D水平分级分为维生素D正常组（17例，25-羟维生素D ≥ 50 nmol /L）和维生素D降低组（63例，25-羟维生素D < 50 nmol /L）。然后再根据25-羟维生素D水平的降低程度进一步将维生素D降低组分为维生素D缺乏组（35例，30 nmol /L ≤25-羟维生素D ≤ 49.9 nmol /L）和维生素D严重缺乏组（28例，25-羟维生素D <30 nmol/L）。采用随机数字表法将维生素D缺乏组患者分为A组（对照组，17例）和B组（干预组，18例），将维生素D严重缺乏组患者分为C组（对照组，14例）和D组（干预组，14例）。A、C组患者给予经胃管、肠内营养管补充淀粉胶囊0.5 g/d；B、D组患者给予经鼻胃管、鼻肠管补充阿法骨化醇软胶囊0.5 g/d，疗程均为7 d。记录所有患者的年龄、性别、25-羟维生素D、氧合指数、急性病生理学和长期健康评价（APACHE）Ⅱ评分、血管外肺水指数（EVLWI）、肺血管通透性指数（PVPI）及28 d死亡情况，采用Cox回归分析影响脓毒性休克致ARDS患者28 d病死率的危险因素。 结果维生素D正常组和维生素D降低组患者25-羟维生素D [（57 ± 4）nmol /L vs.（33 ± 8）nmol /L]、氧合指数[（135 ± 25）mmHg vs.（114 ± 18）mmHg]、APACHEⅡ评分[（14.7 ± 1.6）分vs.（16.0 ± 2.0）分]、EVLWI [（11.4 ± 2.1）mL/kg vs.（14.5 ± 2.7）mL/kg]、PVPI [（3.61 ± 0.32）vs.（5.05 ± 0.68）]及28 d死亡情况（1/17 vs. 20 /63）比较，差异均有统计学意义（t = 11.448、3.872、8.864、5.097、8.409，χ² = 4.626；P均< 0.05）。Cox回归分析结果显示，25-羟维生素D [相对危险度= 4.183，95%置信区间（1.787，10.594），P = 0.012]是脓毒性休克致ARDS患者预后的保护因素。且干预后，C、D组患者25-羟维生素D [（25 ± 4）nmol /L vs.（37 ± 4）nmol /L]、氧合指数[（152 ± 18）mmHg vs.（171 ± 13）mmHg]、APACHEⅡ评分[（12.8 ± 1.4）分vs.（11.0 ± 1.7）分]、EVLWI [（9.5 ± 0.9）mL /kg vs.（7.9 ± 1.4）mL /kg]及PVPI [（3.63 ± 0.28）vs.（2.95 ± 0.48）]比较，差异均有统计学意义（t = 7.493、3.246、3.016、3.420、4.373，P均< 0.05），而28 d死亡情况（6 /14 vs. 4 /14）比较，差异无统计学意义（χ² = 0.622，P = 0.430）。 结论维生素D降低在脓毒性休克致ARDS患者中普遍存在，且维生素D是脓毒性休克ARDS患者28 d病死率的保护因素，而补充维生素D可改善维生素D严重缺乏者ARDS的严重程度。     

Consensus conference definitions for sepsis, septic shock, acute lung injury, and acute respiratory distress syndrome: time for a reevaluation

Definitions for sepsis, septic shock, acute lung injury (ALI), and acute respiratory distress syndrome (ARDS) were developed by consensus conferences with the goal of achieving standardization of terminology and improved homogeneity of patient populations in clinical studies. Although such definitions have been useful in epidemiologic investigations, the criteria specified by the consensus conferences are broad and insufficiently specific to address the problem of heterogeneous mechanisms leading to clinical syndromes. An important challenge is to progress from clinical syndromes, as presently defined, to more specific entities that are delineated by alterations in specific immunologic or biochemical pathways. Such mechanistic definitions will provide more homogeneous groups of patients who can be identified at early stages of their clinical course. This approach encourages focused investigation of pathways leading to organ system dysfunction and death and, also, provides an efficient framework for the development of new therapies useful in critically ill patients.     

Extracorporeal membrane oxygenation in adult acute respiratory distress syndrome

The role of extracorporeal membrane oxygenation (ECMO) in supporting adult refractory respiratory failure continues to evolve. Technical advances and the clinical challenges of H1N1 associated severe ARDS have spurred a resurgence of interest in ECMO. Published systematic review and pooled analyses point out the limitations of available studies, however, a growing body of evidence suggest potential for benefit. Referral to a specialized center with ECMO experience should be considered early after the initiation of high-level ventilator support in adult patients with severe ARDS.     

Improved oxygenation utilizing a prone positioner in patients with acute respiratory distress syndrome

Objectives (a) To determine whether placing patients with acute respiratory distress syndrome in the prone position by a light-weight portable support frame improves oxygenation, (b) whether one can determine which patients benefit from prone positioning, and (c) to determine an effective technique for prone positioning of patients.Design Prospective, controlled trial without blinding.Setting Medical intensive care units in two urban university-affililated hospitals.Patients Fifteen patients meeting a standard definition for acute respiratory distress syndrome were studied prospectively. Each patient acted as his own control for purposes of comparison.Intervention Patients were assigned randomly to begin in either supine or prone positions. The positioning frame was used to turn patients from one position to the other, and oxygenation, ventilation, respiratory mechanics, and hemodynamics were measured.Results Significantly better oxygenation was seen in the prone positions than in the supine (P<0.05). In the overall population there was a decrease in AaDO₂ of 21 mmHg when the patients were placed prone. The groups were then divided into responders (n=9) and nonresponders (n=6). There were significant differences between the groups (but not between positions) regarding PaO₂, baseline, PaCO₂, pulmonary artery pressures, and peak inspiratory pressures on the ventilator and in ICU length of stay and time on mechanical ventilatory support.Conclusion Prone positioning improves oxygenation in the majority of patients studied and can be achieved relatively easily.     

体外膜肺氧合对成人急性呼吸窘迫综合征患者预后影响的荟萃分析

目的 评估体外膜肺氧合(ECMO)对成人急性呼吸窘迫综合征(ARDS)患者预后的影响.方法 计算机检索和手工检索收集1966年1月至2011年7月ECMO治疗成人ARDS的英文和中文临床研究文献,按纳入与排除标准选择文献,提取资料,采用RevMan 5.0软件对数据进行荟萃分析(Meta分析).结果 共纳入9篇文献,其中3篇为随机对照临床试验(RCT)研究,6篇为观察性研究.3篇RCT研究共入选310例患者,ECMO治疗组159例,对照组151例;Meta分析显示:与传统机械通气治疗相比,ECMO治疗不能降低成人重症ARDS患者病死率[优势比(OR)=0.75,95％可信区间(95％CI) 0.45～1.24,P=0.27].9篇文献共入选1058例患者,ECMO治疗组386例,对照组672例;Meta分析显示,与传统机械通气治疗相比,ECMO治疗增加了成人重症ARDS患者的病死率(OR=1.58,95％CI 0.94 ～ 2.67,P=0.08).结论 通过对现有研究的Meta分析表明,ECMO不能改善成人ARDS患者的预后.但由于研究数量较少,研究人群异质性等因素影响,仍需要进行更多大样本、高质量的RCT研究.     

肺部超声在急性呼吸窘迫综合征严重程度评估中的应用

目的探讨肺部超声在急性呼吸窘迫综合征(ARDS)严重程度评估中的应用。方法选取我院诊治的ARDS患者119例,均行胸部CT、肺部超声检查,并制定肺部超声评分(LUS),依据病情分为轻中度组67例和重度组52例,依据预后分为生存组72例和死亡组47例,比较其LUS评分、急性生理学与慢性健康状况评分系统Ⅱ(APACHEⅡ)评分、动脉血氧分压与吸入氧浓度比值(PaO_2/FiO_2)及呼气末正压(PEEP)。Pearson相关性分析法分析LUS与APACHEⅡ评分、PEEP及PaO_2/FiO_2的相关性。绘制LUS评估ARDS严重程度的受试者工作特征(ROC)曲线,并计算其效能。Logistic回归性分析ARDS患者死亡的独立影响因素。结果在LUS、APACHEⅡ评分及PEEP方面比较,重度组明显高于轻中度组,死亡组明显高于生存组(均P0.05);在PaO_2/FiO_2比较,重度组明显低于轻中度组,死亡组明显低于生存组(均P0.05)。相关性分析显示,LUS与APACHEⅡ评分、PEEP均呈正相关(r=0.763、0.593,均P0.05),与PaO_2/FiO_2呈负相关(r=-0.637,P0.05)。ROC曲线分析显示,以LUS 18.00分为截断值,其评估ARDS严重程度的敏感性、特异性及准确率分别为96.15%、94.03%及94.96%。Logistic回归性分析显示,LUS、APACHEⅡ评分、PEEP及PaO_2/FiO_2是ARDS患者死亡的独立影响因素(均P0.05)。结论 LUS与ARDS患者APACHEⅡ评分、PaO_2/FiO_2及PEEP密切相关,可作为评估ARDS严重程度的重要指标,且上述指标是患者死亡的独立影响因素。     

Time-dependency of improvements in arterial oxygenation during partial liquid ventilation in experimental acute respiratory distress syndrome

Background  

The mechanisms by which partial liquid ventilation (PLV) canimprove gas exchange in acute lung injury are still unclear. Therefore, weexamined the time- and dose-dependency of the improvements in arterial oxygentension (PaO₂) due to PLV in eight pigs with experimental lunginjury, in order to discriminate increases due to oxygen dissolved inperfluorocarbon before its intrapulmonary instillation from a persistentdiffusion of the respiratory gas through the liquid column.     

Early prediction of extracorporeal membrane oxygenation eligibility for severe acute respiratory distress syndrome in adults

PurposeAppropriately identifying and triaging patients with newly diagnosed acute respiratory distress syndrome (ARDS) who may progress to severe ARDS is a common clinical challenge without any existing tools for assistance.Materials and methodsUsing a retrospective cohort, a simple prediction score was developed to improve early identification of ARDS patients who were likely to progress to severe ARDS within 7 days. A broad array of comorbidities and physiologic variables were collected for the 12-hour period starting from intubation for ARDS. Extracorporeal membrane oxygenation (ECMO) eligibility was determined based on published criteria from recent ECMO guidelines and clinical trials. Separate data-driven and expert opinion approaches to prediction score creation were completed.ResultsThe study included 767 patients with moderate or severe ARDS who were admitted to the intensive care unit between January 1, 2005, and December 31, 2010. In the data-driven approach, incorporating the ARDS index (a novel variable incorporating oxygenation index and estimated dead space), aspiration, and change of Pao₂/fraction of inspired oxygen ratio into a simple prediction model yielded a c-statistic (area under the receiver operating characteristic curve) of 0.71 in the validation cohort. The expert opinion–based prediction score (including oxygenation index, change of Pao₂/fraction of inspired oxygen ratio, obesity, aspiration, and immunocompromised state) yielded a c-statistic of 0.61 in the validation cohort.ConclusionsThe data-driven early prediction ECMO eligibility for severe ARDS score uses commonly measured variables of ARDS patients within 12 hours of intubation and could be used to identify those patients who may merit early transfer to an ECMO-capable medical center.     

超声在急性呼吸窘迫综合征围静脉-静脉体外膜氧合期中的应用价值

目的探讨经胸超声心动图、血管超声及腹部超声在急性呼吸窘迫综合征(ARDS)患者围静脉-静脉体外膜氧合(V-V ECMO)期的临床应用价值。方法选取我院拟行V-V ECMO支持治疗的ARDS患者13例,分析超声在插管前对患者基本情况的评估结果,以及在插管过程中、V-V ECMO支持治疗期间和脱机后对心脏及血管相关并发症监测情况。结果行V-V ECMO支持治疗的13例ARDS患者中,12例存活至脱机,8例存活至康复出院。V-V ECMO插管过程中,7例在超声引导下调整套管末端位置;V-V ECMO支持治疗期间,2例在超声引导下调整套管末端位置。并发症发生情况:V-V ECMO支持治疗期间血管超声提示2例套管周围血栓形成,腹部超声提示1例腹腔出血;脱机后超声心动图提示1例下腔静脉附壁血栓形成,血管超声提示1例插管同侧下肢深静脉血栓形成。围V-V ECMO期无严重不良事件发生。结论超声在V-V ECMO插管过程中、支持治疗期间及监测并发症方面均具有重要价值。     

Early evolution of arterial oxygenation in severe community-acquired pneumonia: a prospective observational study

PURPOSE: Acute respiratory failure requiring mechanical ventilation in severe community-acquired pneumonia has been shown to be a significant negative prognostic factor. We analyzed the early evolution of the Pao(2)/Fio(2) ratio and evaluated its clinical value as an outcome predictor. MATERIALS AND METHODS: This is a prospective study conducted in a tertiary referral hospital. In 62 adult patients requiring early mechanical ventilation due to severe community-acquired pneumonia, we measured serial changes in Pao(2)/Fio(2) ratio and other clinical variables within the first 48 hours of mechanical ventilation and compared the difference between survivors and nonsurvivors. RESULTS: The initial Pao(2)/Fio(2) ratio was lower in nonsurvivors (n = 27) than in survivors (n = 35) (158.0 +/- 55.8 vs 117.9 +/- 50.6, P = .025). Over the next 48 hours, the ratio increased significantly in survivors but not in nonsurvivors (analysis of variance, P < .001). An increase in Pao(2)/Fio(2) ratio greater than 56 mm Hg had a sensitivity of 75% and a specificity of 81% of survival. A definite causative pathogen was identified in 36 patients (58%) and the 3 most commonly isolated pathogens were Streptococcus pneumoniae, Staphylococcus aureus, and Klebsiella pneumoniae. Ten patients received inadequate initial empirical antimicrobial therapy, in which the Pao(2)/Fio(2) ratio change was significantly less than those who were adequately treated (analysis of variance, P < .001). Mortality was much higher (86% [6/7]) in patients who received inadequate antibiotics and where Pao(2)/Fio(2) ratio change was less than 56 mm Hg. On multivariate analysis, trend changes in Pao(2)/Fio(2) ratio over 48 hours, shock, and Acute Physiology and Chronic Health Evaluation II score were documented to be independent predictors of mortality. CONCLUSIONS: A progressive improvement of Pao(2)/Fio(2) ratio during the first 48 hours of mechanical ventilation indicates favorable outcome. Serial measurement of this ratio should be considered in decision making for therapeutic strategy.     

Small airway remodeling in acute respiratory distress syndrome: a study in autopsy lung tissue

Introduction  

Airway dysfunction in patients with the Acute Respiratory Distress Syndrome (ARDS) is evidenced by expiratory flow limitation and dynamic hyperinflation. These functional alterations have been attributed to closure/obstruction of small airways. Airway morphological changes have been reported in experimental models of acute lung injury, characterized by epithelial necrosis and denudation in distal airways. To date, however, no study has focused on the morphological airway changes in lungs from human subjects with ARDS. The aim of this study is to evaluate structural and inflammatory changes in distal airways in ARDS patients.     

《2004严重感染和感染性休克治疗指南》系列讲座(6)严重感染和感染性休克所致急性呼吸窘迫综合征的机械通气治疗

急性肺损伤(ALI)是急性呼吸衰竭最常见的原因和表现,急性呼吸窘迫综合征(ARDS)是其病情进展的结果。ARDS的发病原因复杂多样,但最常见的为严重感染,25％-42％的ARDS由严重感染引起,其中以肺部和腹腔感染最为多见。顽固性低氧血症是ARDS最突出的临床特征,机械通气是纠正低氧血症的主要治疗手段。ARDS患者大量肺泡塌陷,肺容积显著减少,肺顺应性明显降低,决定了机械通气中必须采用特殊的通气模式和通气条件。     

Programmed multi-level ventilation in COVID-19-related acute respiratory distress syndrome: a multi-center retrospective observational study

ObjectiveWe evaluated pressure-controlled ventilation (PCV) with multiple programmed levels of positive end expiratory pressure (programmed multi-level ventilation; PMLV) in patients with coronavirus disease 2019 (COVID-19)-related acute respiratory distress syndrome (ARDS).MethodsWe conducted a multicenter, retrospective study from November 2020 to February 2021. PMLV was used with PCV in all patients with intensive care admission until improvement in oxygenation (fraction of inspired oxygen [FiO₂] ≤0.50 and oxygen saturation [SpO₂] >92%). The observed outcomes were improvement of hypoxemia, length of mechanical ventilation, partial pressure of carbon dioxide (PaCO₂) stability, and adverse events.ResultsOf 188 mechanically ventilated patients with COVID-19-related ARDS, we analyzed 60 patients treated with PMLV. Hypoxemia improved in 55 (92%) patients, as measured by the change in partial pressure of oxygen/FiO₂ and SpO₂/FiO₂ ratios on day 3 versus day 1, and in 32 (66%) ventilated patients on day 7 versus day 3. The median (interquartile range) length of mechanical ventilation for survivors and non-survivors was 8.4 (4.7–14.9) and 6.7 (3.6–10.3) days, respectively.ConclusionsPMLV appears to be a safe and effective ventilation strategy for improving hypoxemia in patients with COVID-19-related ARDS. Further studies are needed comparing the PMLV mode with the conventional ARDS ventilatory approach.