Pediatric acute lung injury: prospective evaluation of risk factors associated with mortality

RATIONALE: The 1994 American European Consensus Committee definitions of acute lung injury (ALI) and the acute respiratory distress syndrome (ARDS) have not been applied systematically in the pediatric population. OBJECTIVES: The purpose of this study was to evaluate prospectively the epidemiology and clinical risk factors associated with death and prolonged mechanical ventilation in all pediatric patients admitted to two large, pediatric intensive care units with ALI/ARDS using Consensus criteria. METHODS: All pediatric patients meeting Consensus Committee definitions for ALI were prospectively identified and included in a relational database. MEASUREMENTS AND MAIN RESULTS: There were 328 admissions for ALI/ARDS with a mortality of 22%. Multivariate logistic regression analyses revealed (1) the initial severity of oxygenation defect, as measured by the Pa(O2)/FI(O2) ratio; (2) the presence of nonpulmonary and non-central nervous system (CNS) organ dysfunction; and (3) the presence of CNS dysfunction were independently associated with mortality and prolonged mechanical ventilation. A substantial fraction of patients (28%) did not require mechanical ventilation at the onset of ALI; 46% of these patients eventually required intubation for worsening ALI. CONCLUSIONS: Mortality in pediatric ALI/ARDS is high and several risk factors have major prognostic value. In contrast to ALI/ARDS in adults, the initial severity of arterial hypoxemia in children correlates well with mortality. A significant fraction of patients with pediatric ALI/ARDS can be identified before endotracheal intubation is required. These patients provide a valuable group in whom new therapies can be tested.     

小潮气量通气对ALI/ARDS高风险患者疗效及预后的影响分析

目的研究机械通气治疗的急性肺损伤/急性呼吸窘迫综合症(ALI/ARDS)高风险患者,应用小潮气量通气对患者疗效和预后的影响。方法采用随机数字表法将本院重症监护病房(ICU)收治的56例ALI/ARDS高风险患者分为研究组和对照组各28例,研究组采用小潮气量(VT6~8ml/kg)通气治疗,对照组采用常规潮气量(VT10~12ml/kg)通气治疗,比较两组患者治疗后不同时间的血气指标、血清炎症变化及预后差异。结果通气48h、通气96h后两组患者的Pa O2、Pa CO2、氧饱和度、p H值、氧合指数、中心静脉压均较通气即刻显著好转(P0.05)。通气48h、通气96h后两组患者的血清IL-6、TNF-ɑ、CRP水平均较通气即刻显著的降低(P0.05),研究组在通气48h、通气96h后血清IL-6、TNF-ɑ、CRP水平均显著的低于对照组(P0.05)。研究组的ALI/ARDS发病率(14.29%)、ICU治疗时间(9.5±2.6)d、机械通气治疗时间(7.4±1.3)d、住院时间(13.7±3.2)d、死亡率(10.71%),均显著的低于对照组患者(P0.05)。结论 ALI/ARDS高风险患者应用小潮气量机械通气治疗,较常规潮气量通气治疗具有更好的临床效果,预后效果更好。     

Treatment of ARDS

Improved understanding of the pathogenesis of acute lung injury (ALI)/ARDS has led to important advances in the treatment of ALI/ARDS, particularly in the area of ventilator-associated lung injury. Standard supportive care for ALI/ARDS should now include a protective ventilatory strategy with low tidal volume ventilation by the protocol developed by the National Institutes of Health ARDS Network. Further refinements of the protocol for mechanical ventilation will occur as current and future clinical trials are completed. In addition, novel modes of mechanical ventilation are being studied and may augment standard therapy in the future. Although results of anti-inflammatory strategies have been disappointing in clinical trials, further trials are underway to test the efficacy of late corticosteroids and other approaches to modulation of inflammation in ALI/ARDS.     

Future research directions in acute lung injury: summary of a National Heart,Lung, and Blood Institute working group

Acute lung injury (ALI) and its more severe form, the acute respiratory distress syndrome (ARDS), are syndromes of acute respiratory failure that result from acute pulmonary edema and inflammation. The development of ALI/ARDS is associated with several clinical disorders including direct pulmonary injury from pneumonia and aspiration as well as indirect pulmonary injury from trauma, sepsis, and other disorders such as acute pancreatitis and drug overdose. Although mortality from ALI/ARDS has decreased in the last decade, it remains high. Despite two major advances in treatment, low VT ventilation for ALI/ARDS and activated protein C for severe sepsis (the leading cause of ALI/ARDS), additional research is needed to develop specific treatments and improve understanding of the pathogenesis of these syndromes. The NHLBI convened a working group to develop specific recommendations for future ALI/ARDS research. Improved understanding of disease heterogeneity through use of evolving biologic, genomic, and genetic approaches should provide major new insights into pathogenesis of ALI. Cellular and molecular methods combined with animal and clinical studies should lead to further progress in the detection and treatment of this complex disease.     

Epidemiology of acute lung injury and acute respiratory distress syndrome in The Netherlands: a survey

BACKGROUND: The characteristics, incidence and risk factors for acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) may depend on definitions and geography. METHODS: A prospective, 3-day point-prevalence study was performed by a survey of all intensive care units (ICU) in the Netherlands (n=96). Thirty-six ICU's responded (37%), reporting on 266 patients, of whom 151 were mechanically ventilated. The questionnaire included criteria and potential risk factors for ALI/ARDS, according to the North American-European Consensus Conference (NAECC) or the lung injury score (LIS>or=2.5). RESULTS: Agreement between definitions was fair (kappa 0.31-0.42, P=0.001). ALI/ARDS was characterized, regardless of definition, by radiographic densities, low oxygenation ratios, high inspiratory O(2) and airway pressure requirements. Depending on definitions, ALI and ARDS accounted for about 12-33% and 7-9% of ICU admissions per year, respectively, constituting 21-58% (ALI) and 13-16% (ARDS) of all mechanically ventilated patients. The annual incidences of ALI and ARDS are 29.3 (95%CI 18.4-40.1) and 24.0 (95%CI 14.2-33.8) by NAECC, respectively, and are, respectively, 83.6 (95%CI 65.3-101.9) and 20.9 (95%CI 11.7-30.1) by LIS per 100,000. Risk factors for ALI/ARDS were aspiration, pneumonia, sepsis and chronic alcohol abuse (the latter only by NAECC). CONCLUSION: The effect of definitions of ALI/ARDS on mechanical ventilation in the Netherlands is small. Nevertheless, the incidence of ALI/ARDS may be higher than in other European countries but lower than in the USA, and the incidence of ALI by LIS may overestimate compared to that by NAECC. Aspiration, pneumonia, sepsis and chronic alcohol abuse are major risk factors, largely independent of definitions.     

Evidencias de la posición en decúbito prono para el tratamiento del síndrome de distrés respiratorio agudo: una puesta al día

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) have high incidence and mortality rates. Most of the recently introduced treatments have failed to improve the prognosis of patients with ALI or ARDS or to reduce mortality. Several studies have shown improved oxygenation in the prone position during mechanical ventilation in patients with ARDS. However, current evidence strongly suggests that placing ARDS patients in prone position does not improve survival or reduce the duration of mechanical ventilation. Therefore, though in clinical practice this position may improve refractory hypoxemia in patients with ARDS, there is no evidence to support its systematic use.     

Etiology and outcomes of pulmonary and extrapulmonary acute lung injury/ARDS in a respiratory ICU in North India

OBJECTIVE: Outcomes in patients with ARDS/acute lung injury (ALI) may be dependent on the underlying cause. We describe the case mix, clinical behavior, and outcomes of patients with ALI/ARDS resulting from pulmonary causes (ALI/ARDSp) and extrapulmonary causes (ALI/ARDSexp). DESIGN: Retrospective study conducted between January 2001 and June 2005. SETTING: Respiratory ICU (RICU) of a tertiary care hospital in northern India. PATIENTS: All patients fulfilling the criteria for ALI/ARDS and requiring mechanical ventilation for > 24 h. MEASUREMENTS AND RESULTS: Of the 180 patients (ARDS, 140 patients; ALI, 40 patients), 123 patients had ALI/ARDSp, whereas 57 patients had ALI/ARDSexp. The most common cause of ALI/ARDSp was infective pneumonia, whereas the most common cause of ALI/ARDSexp was sepsis. At ICU admission, although patients with ALI/ARDSexp were sicker than those with ALI/ARDSp, there was no difference between the two groups of patients in the development of new organ dysfunction/failure (Delta sequential organ failure assessment [SOFA] scores) or the time to develop the first organ dysfunction/failure (assessed by SOFA scores). The median length of RICU stay was similar in the two groups (5 days [interquartile range (IQR), 6 days] vs 5 days [IQR, 9.5 days], respectively, in patients with ALI/ARDSp and ALI/ARDSexp; p = 0.4). The hospital mortality rate was 47.8% and was not significantly different between the two groups (ALI/ARDSp group, 43.1%; ALI/ARDSexp group, 57.9%; p = 0.06). Multivariate analysis showed the following risk factors for death in the ICU: female gender (odds ratio [OR], 0.49; 95% confidence interval [CI], 0.25 to 0.94); SOFA scores (OR, 1.18; 95% CI, 1.07 to 1.3); and DeltaSOFA scores (OR, 1.24; 95% CI, 1.09 to 1.41). There was no significant effect of the category of ARDS on outcome (OR, 1.6; 95% CI, 0.8 to 3.2). CONCLUSIONS: Although patients with ALI/ARDSexp are sicker on ICU admission, the underlying cause of ARDS does not affect the length of ICU stay or hospital survival time.     

Incidence and mortality after acute respiratory failure and acute respiratory distress syndrome in Sweden, Denmark, and Iceland. The ARF Study Group.

To determine the incidence and 90-d mortality of acute respiratory failure (ARF), acute lung injury (ALI), and the acute respiratory distress syndrome (ARDS), we carried out an 8-wk prospective cohort study in Sweden, Denmark, and Iceland. All intensive care unit (ICU) admissions (n = 13,346) >/= 15 yr of age were assessed between October 6th and November 30th, 1997 in 132 of 150 ICUs with resources to treat patients with intubation and mechanical ventilation (I + MV) >/= 24 h. ARF was defined as I + MV >/= 24 h. ALI and ARDS were defined using criteria recommended by the American-European Consensus Conference on ARDS. Calculation to correct the incidence for unidentified subjects from nonparticipating ICUs was made. No correction for in- or out-migration from the study area was possible. The population in the three countries >/= 15 yr of age was 11.74 million. One thousand two hundred thirty-one ARF patients were included, 287 ALI and 221 ARDS patients were identified. The incidences were for ARF 77.6, for ALI 17.9, and for ARDS 13.5 patients per 100,000/yr. Ninety-day mortality was 41.0% for ARF, including ALI and ARDS patients, 42.2% for ALI not fulfilling ARDS criteria, and 41.2% for ARDS.     

Prevalence and mortality of acute lung injury and ARDS after lung resection

STUDY OBJECTIVES: To describe the frequency and outcome of patients with acute lung injury (ALI) and ARDS who require mechanical ventilation (MV) after lung resection, and to analyze preoperative and perioperative variables associated with mortality. METHODS: We retrospectively reviewed the case records of all patients who underwent lung resection and acquired ALI and/or ARDS and required invasive MV and ICU admission at a tertiary-care cancer center from January 1, 2002, to December 31, 2004. Preoperative and perioperative information including ICU-specific variables and outcome data were analyzed. Data are presented as median (range). RESULTS: During the study period, 2,039 patients underwent a total of 2,192 lung resections. ALI/ARDS developed in 50 patients (2.45%). The prevalence of ALI/ARDS by procedure was as follows: pneumonectomy, 7.9% (10 cases in 126 procedures); lobectomy/bilobectomy, 2.96% (31 cases in 1,047 procedures); and sublobar resection, 0.88% (9 cases in 1,019 procedures). There were 28 men (56%) and 22 women (44%). Median age was 68.5 years (range, 44 to 88 days). Median time of presentation to the ICU with ALI/ARDS following surgery was 4 days (range, 1 to 22 days). Median ICU length of stay was 10 days (range, 2 to 43 days), and median hospital LOS was 26.5 days (range, 6 to 93 days). During hospitalization, 20 of the 50 patients (40%) died: 16 in the ICU and 4 after ICU discharge. The mortality rate was highest after pneumonectomy (50%), followed by lobectomy (42%) and sublobar resections (22%). Although increased age was associated with a higher ICU mortality, none of the preoperative and perioperative variables were significantly associated with hospital mortality. There was a marginally significant association between mortality and time of presentation to the ICU after surgery (p = 0.06). CONCLUSIONS: Our results confirm that ALI/ARDS after lung resection is associated with a high mortality in patients who require invasive MV and ICU care.     

Recruitment maneuvers in three experimental models of acute lung injury. Effect on lung volume and gas exchange

Recruitment maneuvers (RM), consisting of sustained inflations at high airway pressures, have been advocated as an adjunct to mechanical ventilation in acute respiratory distress syndrome (ARDS). We studied the effect of baseline ventilatory strategy and RM on end-expiratory lung volume (EELV) and oxygenation in 18 dogs, using three models of acute lung injury (ALI; n = 6 in each group): saline lavage (LAV), oleic acid injury (OAI), and intratracheal instillation of Escherichia coli (pneumonia; PNM). All three models exhibited similar degrees of lung injury. The PNM model was less responsive to positive end-expiratory pressure (PEEP) than was the LAV or OAI model. Only the LAV model showed an oxygenation response to increasing tidal volume (VT). After RM, there were transient increases in Pa(O(2)) and EELV when ventilating with PEEP = 10 cm H(2)O. At PEEP = 20 cm H(2)O the lungs were probably fully recruited, since the plateau airway pressures were relatively high ( approximately 45 cm H(2)O) and the oxygenation was similar to preinjury values, thus making the system unresponsive to RM. Sustained improvement in oxygenation after RM was seen in the LAV model when ventilating with PEEP = 10 cm H(2)O and VT = 15 ml/kg. Changes in EELV correlated with changes in Pa(O(2)) only in the OAI model with PEEP = 10 cm H(2)O. We conclude that responses to PEEP, VT, and RM differ among these models of ALI. RM may have a role in some patients with ARDS who are ventilated with low PEEP and low VT.     

Application of the acute respiratory distress syndrome network low-tidal volume strategy to pediatric acute lung injury

In summary, most of the available data suggest that pediatric patients should be ventilated with low tidal volumes. The 6-mL/kg IBW tidal volume strategy as used in the ARDSNet studies is a reasonable target, having since been rigorously tested in several large, clinical trials (adult and pediatric). The mortality associated with ALI in these studies has never been lower, certainly supporting continued use of the 6 mL/kg target tidal volume as the "gold standard" and, thus, eliminating any equipoise in designing a pediatric trial comparing 6 mL/kg to a larger tidal volume. With mortality rates in children from ALI nearing 8% to 22% and with no clear surrogate outcomes identified to date, the sample sizes needed to show a significant clinical effect would be prohibitively large. Nonetheless, future research should compare 6 mL/kg IBW to even smaller tidal volumes or to high frequency ventilation in an attempt to further reduce the mortality associated with ALI and ARDS in the pediatric population.     

Prospective, randomized, controlled pilot study of partial liquid ventilation in adult acute respiratory distress syndrome

We evaluated the safety and efficacy of partial liquid ventilation (PLV) with perflubron in adult patients with acute lung injury and the acute respiratory distress syndrome (ARDS) in a multicenter, prospective, controlled, randomized exploratory clinical trial. Ninety adult patients with PaO2/FIO2 ratios > 60 and < 300 with ARDS for no more than 24 hours were randomized to receive PLV (n = 65) with administration of perflubron through an endotracheal tube sideport or conventional mechanical ventilation (CMV, n = 25) for a maximum of five days. Although a significant reduction in progression to ARDS was noted among patients with PLV, no significant differences in the number of days free from the ventilator at 28 days (CMV = 6.7 +/- 1.8, PLV = 6.3 +/- 1.0 days, p = 0.85), the incidence of mortality (CMV = 36%, PLV = 42%, p = 0.63), or any pulmonary-related parameter were observed. During a post hoc subgroup analysis, significantly more rapid discontinuation of mechanical ventilation (p = 0.045) and a trend toward an increase in the number of days free from the ventilator at 28 days (CMV = 3.2 +/- 1.9, PLV = 8.0 +/- 2.2 days, p = 0.06) were observed during PLV among those patients under 55 years of age with acute lung injury or ARDS. Episodes of hypoxia, respiratory acidosis, and bradycardia occurred more frequently in the PLV group, but these were transient and self-limited. Further evaluation of PLV is warranted to further define beneficial effects in well-defined groups of patients and also to gain additional information regarding safety.     

High-frequency ventilation for acute lung injury and ARDS

In patients with acute lung injury (ALI) and ARDS, conventional mechanical ventilation (CV) may cause additional lung injury from overdistention of the lung during inspiration, repeated opening and closing of small bronchioles and alveoli, or from excessive stress at the margins between aerated and atelectatic lung regions. Increasing evidence suggests that smaller tidal volumes (VTs) and higher end-expiratory lung volumes (EELVs) may be protective from these forms of ventilator-associated lung injury and may improve outcomes from ALI/ARDS. High-frequency ventilation (HFV)-based ventilatory strategies offer two potential advantages over CV for pateints with ALI/ARDS. First, HFV uses very small VTs, allowing higher EELVs with less overdistention than is possible with CV. Second, despite the small VTs, high respiratory rates during HFV allow the maintenance of normal or near-normal PaCO(2) levels. In this review, the use of HFV as a lung protective strategy for patients with ALI/ARDS is discussed.     

Significance of von Willebrand factor in septic and nonseptic patients with acute lung injury

Systemic endothelial activation and injury are important causes of multiorgan system failure. We hypothesized that plasma levels of von Willebrand factor (VWF), a marker of endothelial activation and injury, would be associated with clinical outcomes in acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). In 559 patients with ALI/ARDS enrolled in the National Heart, Lung, and Blood Institute ARDS Network trial of two VT strategies, plasma VWF levels were measured at randomization (mean 350 +/- 265% of normal control plasma) and Day 3 (344 +/- 207%). Baseline VWF levels were similar in patients with and without sepsis, and were significantly higher in nonsurvivors (435 +/- 333%) versus survivors (306 +/- 209%) even when controlling for severity of illness, sepsis, and ventilator strategy (increased odds ratio of death of 1.6 per SD size increase in VWF; 95% confidence interval, 1.4-2.1). Higher VWF levels were also significantly associated with fewer organ failure-free days. Ventilator strategy had no effect on VWF levels. In conclusion, the degree of endothelial activation and injury is strongly associated with outcomes in ALI/ARDS, regardless of the presence or absence of sepsis, and is not modulated by a protective ventilatory strategy. To improve outcomes further, new treatment strategies targeted at the endothelium should be investigated.     

Recruitment maneuvers in acute lung injury

Maintaining optimal lung recruitment has a marked effect on the outcome of patients who suffer from ARDS. RMs superimposed on mechanical ventilation have the potential to recruit atelectatic lungs in the course of general anesthesia; however, the physiologic benefits are less evident in ARDS patients who are ventilated at low VT values and high PEEP levels. Currently, the following technical aspects warrant further investigation: optimal time (the first hours after intubation or the first days of ARDS), duration (from 15 seconds to 2 minutes), mode (continuous positive end-expiratory pressure or pressure controlled ventilation with high PEEP), and type of patients (pulmonary versus extrapulmonary ARDS). Before the routine implementation of RMs to recruit the lungs fully in ARDS patients, clinicians also need more information on side effects and contraindications. Although RMs are transient, they may be associated with complications such as hypotension, bradycardia, and barotrauma. Moreover, further studies are needed to compare the efficacy of periodic high-pressure RMs that are superimposed on mechanical ventilation with ventilation using high PEEP levels and low VT values without RMs in patients who have early ARDS after initial hemodynamic stabilization.     

小潮气量通气对创伤性ARDS的疗效分析

目的：探讨小潮气量通气对创伤性ARDS的疗效。方法：回顾性分析48例创伤性ARDS患者的病历资料，分为两组，大潮气量组23例，VT10～12ml／kg理想体重，PEEP5～10cmH2O，平台压35-50cmH2O；小潮气量组25例，VT5～8ml／kg理想体重，PEEP10～15cmH20，平台压≤35cmH2O。观察两组通气治疗前、后3dPaO2／FiO2、PaCO2、pH值及气压伤的发生情况和ICU住院期间病死率。结果：通气治疗后两组PaO2／FiO2均较通气治疗前明显升高（P〈0．05，P〈0．01），但在第3天，小潮气量组PaO2／FiO2明显低于大潮气量组（P〈0．01）；小潮气量组出现明显高碳酸血症，但在机体可耐受范围。大潮气量组出现3例气压伤，小潮气量组无气压伤发生。小潮气量组病死率16％（4／25）低于大潮气量组26．08％（6／23）（P〉0．05）。结论：小潮气量通气可改善创伤性ARDS患者氧合状态和预后，减少呼吸机相关性肺损伤的发生。     

Tidal volume reduction in patients with acute lung injury when plateau pressures are not high

Use of a volume- and pressure-limited mechanical ventilation strategy improves clinical outcomes of patients with acute lung injury and acute respiratory distress syndrome (ALI/ARDS). However, the extent to which tidal volumes and inspiratory airway pressures should be reduced to optimize clinical outcomes is a controversial topic. This article addresses the question, "Is there a safe upper limit to inspiratory plateau pressure in patients with ALI/ARDS?" We reviewed data from animal models with and without preexisting lung injury, studies of normal human respiratory system mechanics, and the results of five clinical trials of lung-protective mechanical ventilation strategies. We also present an original analysis of data from the largest of the five clinical trials. The available data from each of these assessments do not support the commonly held view that inspiratory plateau pressures of 30 to 35 cm H2O are safe. We could not identify a safe upper limit for plateau pressures in patients with ALI/ARDS.     

Higher urine nitric oxide is associated with improved outcomes in patients with acute lung injury

RATIONALE: Nitrogen oxide (NO) species are markers for oxidative stress that may be pathogenic in acute lung injury (ALI). OBJECTIVES: We tested two hypotheses in patients with ALI: (1) higher levels of urine NO would be associated with worse clinical outcomes, and (2) ventilation with lower VT would reduce urine NO as a result of less stretch injury. METHODS: Urine NO levels were measured by chemiluminescence in 566 patients enrolled in the National Heart Lung and Blood Institute Acute Respiratory Distress Syndrome Network trial of 6 ml/kg versus 12 ml/kg VT ventilation. The data were expressed corrected and uncorrected for urine creatinine (Cr). RESULTS: Higher baseline levels of urine NO to Cr were associated with lower mortality (odds ratio, 0.43 per log(10) increase in the ratio), more ventilator-free days (mean increase, 1.9 d), and more organ-failure-free days (mean increase, 2.3 d) on multivariate analysis (p < 0.05 for all analyses). Similar results were obtained using urine NO alone. NO to Cr levels were higher on Day 3 in the 6 ml/kg than in the 12 ml/kg VT group (p = 0.04). CONCLUSIONS: Contrary to our hypothesis, higher urine NO was associated with improved outcomes in ALI at baseline and after treatment with the 6 ml/kg VT strategy. Higher endogenous NO may reflect less severe lung injury and better preservation of the pulmonary and systemic endothelium or may serve a protective function in patients with ALI.     

Statins for the prevention and treatment of acute lung injury and acute respiratory distress syndrome: A systematic review and meta‐analysis

The purpose of this meta‐analysis was to assess whether statins could reduce the morbidity of acute lung injury and acute respiratory distress syndrome (ALI/ARDS) in high‐risk patients and improve the clinical outcomes of patients with ALI/ARDS. Studies were obtained from PubMed, Medline, Embase and Cochrane Central Register of Controlled Trials. Randomized controlled trials (RCTs) and cohort studies, which reported morbidity, mortality, ventilator‐free days, length of stay in intensive care unit and hospital or oxygenation index, were included in our meta‐analysis. Risk ratio (RR) and weighted mean difference (WMD) were calculated using fixed or random effect model. A total of 13 studies covering 12 145 patients were included. Both the only RCT (P = 0.10) and cohort studies (RR, 1.02; 95% CI, 0.67 to 1.55; P = 0.94) showed that statin therapy did not lower the morbidity of ALI/ARDS in high‐risk patients. The mortality of ALI/ARDS patients was less likely to be improved by statins (RCT, RR, 1.00; 95% CI, 0.84 to 1.20; P = 0.97; cohort studies, RR, 1.04; 95% CI, 0.85 to 1.27; P = 0.72). Moreover, no significant difference was observed in ventilator‐free days, length of stay in intensive care unit as well as hospital and oxygenation index. This meta‐analysis suggests that statins neither provide benefit for lowering the morbidity of ALI/ARDS in high‐risk patients nor improve the clinical outcomes of ALI/ARDS patients. Hence, it may not be appropriate to advocate statin use for the prevention and treatment of ALI/ARDS.