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Acute lung injury and post-cardiac arrest syndrome: a narrative review

Abstract

Background

Post-cardiac arrest syndrome (PCAS) presents a multifaceted challenge in clinical practice, characterized by severe neurological injury and high mortality rates despite advancements in management strategies. One of the important critical aspects of PCAS is post-arrest lung injury (PALI), which significantly contributes to poor outcomes. PALI arises from a complex interplay of pathophysiological mechanisms, including trauma from chest compressions, pulmonary ischemia–reperfusion (IR) injury, aspiration, and systemic inflammation. Despite its clinical significance, the pathophysiology of PALI remains incompletely understood, necessitating further investigation to optimize therapeutic approaches.

Methods

This review comprehensively examines the existing literature to elucidate the epidemiology, pathophysiology, and therapeutic strategies for PALI. A comprehensive literature search was conducted to identify preclinical and clinical studies investigating PALI. Data from these studies were synthesized to provide a comprehensive overview of PALI and its management.

Results

Epidemiological studies have highlighted the substantial prevalence of PALI in post-cardiac arrest patients, with up to 50% of survivors experiencing acute lung injury. Diagnostic imaging modalities, including chest X-rays, computed tomography, and lung ultrasound, play a crucial role in identifying PALI and assessing its severity. Pathophysiologically, PALI encompasses a spectrum of factors, including chest compression-related trauma, pulmonary IR injury, aspiration, and systemic inflammation, which collectively contribute to lung dysfunction and poor outcomes. Therapeutically, lung-protective ventilation strategies, such as low tidal volume ventilation and optimization of positive end-expiratory pressure, have emerged as cornerstone approaches in the management of PALI. Additionally, therapeutic hypothermia and emerging therapies targeting mitochondrial dysfunction hold promise in mitigating PALI-related morbidity and mortality.

Conclusion

PALI represents a significant clinical challenge in post-cardiac arrest care, necessitating prompt diagnosis and targeted interventions to improve outcomes. Mitochondrial-related therapies are among the novel therapeutic strategies for PALI. Further clinical research is warranted to optimize PALI management and enhance post-cardiac arrest care paradigms.

Graphical Abstract

Introduction

Despite advancements in the management of post-cardiac arrest syndrome (PCAS), a significant proportion of patients with PCAS experiences severe neurological injury and high mortality rates [1,2,3,4]. PCAS is characterized by a complex interplay of systemic inflammation, ischemia–reperfusion (IR) injury, and multi-organ dysfunction, all of which contribute to the overall poor prognosis [5,6,7,8]. Emerging evidence has identified the lungs as a crucial organ after cardiac arrest (CA) and cardiopulmonary resuscitation (CPR), with lung injuries including acute respiratory distress syndrome (ARDS), significantly impacting patient outcomes [9,10,11,12,13,14].

The pathogenesis of post-arrest lung injury (PALI) is complex, involving trauma from chest compressions, pulmonary IR injury, aspiration, hyperoxia, and systemic inflammation [9, 11, 12, 15]. The specific underlying mechanisms remain still largely elusive, necessitating further research. This review aims to elucidate the complex pathophysiological landscape of PALI and emphasize the importance of lung-protective strategies in improving patient outcomes post-CA.

Epidemiology

The incidence and clinical significance of PALI have gained substantial attention in recent years. Emerging evidence have suggested the prevalence of pulmonary complications in the aftermath of CA, particularly following the successful return of spontaneous circulation (ROSC), with up to 50% of CA survivors developing acute lung injury (ALI) [11, 16,17,18,19] (Table 1). Clinical studies have identified lung injury rates as high as 79% in patients undergoing CPR, as detected by computed tomography (CT) [16, 17]. The ALI following CPR can manifest as lung edema, thoracic skeletal injuries, and lung IR injury [17, 18]. These findings underscore the substantial burden of lung injury in PCAS, necessitating comprehensive evaluation and management of pulmonary complications.

Table 1 Studies reporting the prevalence of post-arrest lung injury in post-cardiac arrest syndrome

Pathophysiology

Primary causes of PALI

The multifactorial etiologies, which contribute to the complex pathophysiology of PALI, include trauma induced by chest compressions, barotrauma resulting from mechanical ventilation, aspiration during and after CA/CPR, and IR injury within the pulmonary system post-CA [15].

Traumatic lung injury, which manifests as pulmonary contusion induced by chest compression and barotrauma, is frequently observed with pathologic features such as pulmonary hemorrhage, pulmonary edema, and atelectasis secondary to physical disruption of alveolar capillary membranes [14, 20]. The incidence of chest compression-related pulmonary contusions ranges from 41 to 100%, with bilateral lung contusions seen in most of CA patients [16,17,18,19].

Aspiration is frequently observed during CA/CPR, with a high incidence of 20–65% [21,22,23,24]. In particular, in patients with OHCA, aspiration of gastric contents has been reported to occur in approximately 30% of patients during or after CPR [25, 26]. Aspiration of acidic gastric fluid or oropharyngeal secretions can result in increased alveolar-capillary permeability, further increasing inflammation and exacerbating lung injury [24]. Complications of aspiration in patients with CA can lead to respiratory failure. One study reported that aspiration was associated with a significantly lower 30-day survival rate compared to CA due to other causes of respiratory failure [27]. Although it is often difficult to determine whether aspiration occurred before, during, or after CPR, a higher level of care needs to be considered to prevent aspiration and the subsequent severity of PALI.

Pulmonary IR injury is a complex pathophysiological process that significantly contributes to morbidity and mortality in a wide range of clinical scenarios, including PCAS, lung transplantation, cardiopulmonary bypass, and ARDS. This condition is marked by a pronounced increase in alveolar-capillary permeability, a hallmark of the disrupted pulmonary barrier function [28]. At the cellular level, IR injury in the lung is characterized by the induction of apoptosis and the robust production of reactive oxygen species (ROS), initiating a cascade of inflammatory responses. Central to this inflammatory milieu is the upregulation of a spectrum of cytokines, including tumor necrosis factor-alpha (TNF-α), interferon-gamma (IFN-γ), and a series of interleukins such as interleukin (IL)-8, IL-10, IL-12, and IL-18 [29, 30]. These mediators play pivotal roles in orchestrating the local and systemic inflammatory response, exacerbating tissue damage during the critical phases of circulatory disruption and subsequent reperfusion. Cell apoptosis in the lung after IR could be more detrimental to the lung than cell necrosis and associated inflammation [31]. Moreover, recent studies have shown that mitochondrial DNA (mtDNA) has been associated with the development of ARDS [32,33,34,35,36]. Elevated circulating levels of mtDNA are found in patients with ALI, which correlates with poor outcomes [36, 37], suggesting plasma mtDNA released from damaged mitochondria as damage-associated molecular patterns (DAMPs) may induce lung injury.

ARDS post-CA

ARDS frequently follows both out-of-hospital cardiac arrest (OHCA) [38] and in-hospital cardiac arrest (IHCA) [39], with PALI presenting as a spectrum of pulmonary damage. The multifaceted nature of PALI, compounded by systemic IR injury and inflammatory response, can exacerbate poor outcomes, with high oxygen concentrations during CPR, pulmonary contusions, and aspiration further increasing the risk of ARDS through oxidative stress mechanisms [40,41,42]. A retrospective analysis of OHCA patients by Johnson et al. reported a 48% incidence of ARDS among mechanically ventilated OHCA patients, with an average P/F ratio of 155 mmHg, corresponding to moderate ARDS. Shih et al. reported that approximately three-quarters of IHCA patients experienced ARDS post-ROSC [39]. In an unadjusted analysis, the presence of ARDS was linked to fewer alive-and-ventilator-free days across 28 days with a median of 1 day as compared to 18 days in patients without ARDS, though this association did not achieve statistical significance upon multivariate analysis [39]. These findings indicate that ARDS is a frequent complication post-CA, suggesting an important area for future therapeutic strategies to improve outcomes post-CA. Given its prevalence and impact, ARDS management in PCAS patients should align with established ARDS protocols to mitigate the risks of prolonged ventilation and increased mortality.

Lung compliance post-CA

Previous research has demonstrated that pulmonary dysfunction following CA is associated with impaired gas exchange, increased pulmonary edema, and the release of pro-inflammatory cytokines [43]. These factors can further contribute to reduced lung compliance and exacerbate lung injury. Additionally, the utilization of mechanical ventilation, almost always required for the management of PCAS, can impact lung compliance, and potentially contribute to lung injury if not diligently controlled [44].

Respiratory system compliance, consisting of pulmonary and chest wall compliance, refers to the lung capacity to expand and adapt to volume changes during the respiratory cycle. Pulmonary components are influenced by various factors, including lung tissue elasticity and the presence of pathologic conditions. The chest wall compliance is often affected by intrinsic respiratory muscle tone, and certain pathological conditions such as deformities of the chest wall from traumatic rib fractures or burns. Following CPR, decreased lung compliance may be a result of factors such as IR injury, systemic inflammation, and ventilation-associated lung injury (VALI). Chest wall compliance may be affected by chest wall trauma from CPR [45, 46]. A study assessing lung compliance in patients with PCAS reported a mean lung compliance of 0.051 ± 0.011 L/cm H2O [46], with a notable decrease at lower lung volumes suggesting the risk of alveolar collapse. The duration of CPR further exacerbates this decline in compliance. Furthermore, decreased lung compliance, a prominent feature of ARDS, may explain higher risk of lung injury following CA. This was demonstrated in a study of PCAS patients who developed ARDS [47]. This relationship underscores the need for vigilant respiratory management aimed at preserving lung function and improving survival outcomes with intact neurological function.

Pulmonary edema and mechanical chest compression

Pulmonary edema following resuscitation is typically transient and considered hydrostatic in nature. However, the exact mechanisms underlying this condition remain to be definitively determined. Potential contributing factors include decreased left ventricular contractility, ineffective chest compressions that fail to adequately propel blood forward, and the reverse flow of blood into the lungs. This backward movement of the blood can cause elevated left ventricular filling pressures and left atrial pressures, further contributing to pulmonary edema during and immediately after CA, while the heart is still stunned.

Mechanical chest compression (MCC) during CPR is associated with an increased incidence of pulmonary edema compared to manual compressions [11]. The pulmonary edema which is characterized by increased lung fluid volume and weight, along with reduced oxygenation and respiratory system compliance, underscores the physiological impact of MCC resuscitation on lung condition [11]. Magliocca et al. demonstrated that MCC notably exacerbates CPR-induced lung edema, a finding consistent across animal models and OHCA patients [11]. However, no worsening has been observed in survival to discharge or length of ICU stay due to the MCC effect. The hemodynamic effects of piston-based devices, while improving blood flow, may also exacerbate vascular congestion by the pressure aspiration effect, hinting at a complex interplay of factors leading to transient pulmonary edema [48].

Assessment and diagnosis

Diagnostic imaging plays a crucial role in evaluating the causes and complications after CA/CPR. Imaging techniques, such as chest x-rays, CT, and lung ultrasound, are instrumental in identifying common lung injury manifestations, such as ground-glass opacities predominantly located in the posterior segments of the lungs [16]. Lung injuries resulting from chest compressions during CPR can lead to pulmonary hemorrhage and edema. These conditions stem from the disruption of alveolar-capillary membranes, pulmonary IR injury, and the aspiration of gastric and oropharyngeal secretions as described above. The differentiation between aspiration pneumonia and lung injury through imaging can be challenging due to overlapping patterns in dependent lung areas [16].

Chest x-rays can be used to identify chest complications after CA/CPR, including rib and sternal fractures, pericardial effusions, and lung injury [49]. A study involving chest x-rays of 44 patients post-CA/CPR revealed increased opacities in 63.6% of the cases, underscoring the prevalence of lung injuries [16]. However, CT scans within the same study group showed a higher detection rate of lung injuries at 79.5%, including in patients with normal chest x-rays, highlighting CT’s superior diagnostic capability [16].

Quantitative CT evaluation offers a detailed assessment of lung injury severity after successful CPR [14]. A study using a porcine ventricular fibrillation model revealed ALI on CT, such as intense parenchymal and ground-glass opacifications, which are indicative of pulmonary edema and alveolar damage, respectively [14]. Further, these changes were more sensitive than the oxygenation index using blood gas analysis, indicating CT’s enhanced sensitivity over traditional blood gas analysis. The utility of CT in detecting pulmonary edema post-resuscitation has been validated in both animal studies and human cases, emphasizing the need for early CT examination for comprehensive lung injury assessment post-CA/CPR [11]. Clinically, CT must be considered standard of care when feasible in PCAS.

Lung ultrasound emerges as a rapid and non-invasive tool for bedside lung injury assessment and monitoring lung injury post-CA [50, 51]. We et al. reported that the lung ultrasound score (LUS), calculated from four findings; (1) presence of lung sliding with A lines or fewer than two isolated B lines, (2) well-defined B lines, (3) multiple coalescent B lines, (4) presence of tissue pattern characterized by dynamic air bronchograms, was useful in assessing lung status and degree of lung injury in a porcine CA model [10].

The extravascular lung water (EVLW) and pulmonary vascular permeability index (PVPI) by the pulse index continuous cardiac output (PiCCO) technology using transpulmonary thermodilution are useful markers of severity of lung injury [52]. In ARDS patients, a strong correlation exists between LUS, EVLW, and PVPI, with early measurements serving as good prognostic indicators [53, 54]. Given the significant correlation of these markers in both ARDS and post-CA contexts, PiCCO technology could aid in detecting lung injuries in PCAS patients, albeit with considerations for its cost, invasiveness, and complexity [10].

Potential therapeutic strategies for PALI

Tidal volume management

Following CA/CPR, up to 50% of resuscitated patients develop lung injury that meets the criteria for ARDS during their intensive care unit (ICU) stay, highlighting the need for lung-protective ventilation strategies in patients with PCAS [38]. A meta-analysis of critically ill non-CA patients without ARDS reported that low tidal volume (VT) was associated with lower lung infection, atelectasis, and mortality [55]. Despite limited data on ventilator management for PCAS, current practices often involve higher VT and driving pressures (ΔP), which may exacerbate ventilator-induced lung injury (VILI) [56]. In a study using a two-center retrospective cohort of OHCA patients, Beitler et al. showed that lower VT [< 8 ml/kg predicted body weight (PBW)] was associated with improved functional outcomes [57]. Furthermore, a preplanned sub-analysis of the Target Temperature Management (TTM)-2 trial by Robba et al. has demonstrated that mechanical output, ΔP, and ventilation rate, as well as positive end-expiratory pressure (PEEP), respiratory plateau pressure (PPLAT), and single VT, were independently associated with 6-month mortality in the post-resuscitation respiratory setting [58]. European guidelines advocate for VT of 6–8 ml/kg PBW in brain-injured and post-CA patients, although evidence in the post-CA context is sparse [59]. These findings underscore the critical need for lung-protective strategies with lower VT (6–8 ml/kg PBW) to prevent VILI, advocating for more careful and frequent adjustments of ventilator settings in the PCAS care to avoid VT higher than 8 ml/kg PBW. To meet the ventilatory needs of the patient, respiratory rate should be adjusted to allow for a higher minute ventilation to avoid hypercarbic respiratory failure and potential worsening brain injury [60]. However, it must be emphasized that given frequently hypermetabolic state of PCAS, very high respiratory rates may lead to inappropriately high airway pressures which the clinician should be vigilantly monitoring. Lastly, it must be noted that unless the patient is deeply sedated or paralyzed, the respiratory rate may be centrally driven to be high, irrespective of the respiratory rate set by the ventilator.

Managing hypercapnia

Along with the proper management of VT, the impacts of hypercapnia on cerebral blood flow and intracranial pressure (ICP) are critical considerations in post-CA care. Studies reported that mild hypercapnia improved cerebral oxygenation but did not increase ICP or cerebral edema, suggesting potential therapeutic benefits in the acute phase following resuscitation [61, 62]. However, a recent randomized controlled trial (RCT) challenged this notion by demonstrating that, in comatose patients resuscitated after OHCA, targeted mild hypercapnia did not result in superior neurological outcomes at 6 months compared to targeted normocapnia [63]. Despite this, the absence of consistent evidence regarding the optimal role of hypercapnia post-CA has not deterred the clinical practice of permitting mild hypercapnia as an integral component of lung-protective ventilation strategies. This approach is primarily aimed at reducing the risk of VILI while potentially aiding cerebral perfusion. As such, PaCO2 levels are often maintained within a target range of 35 to 50 mmHg, striking a balance between ensuring sufficient oxygenation and mitigating the risk of negative cerebral consequences [64]. This nuanced approach underscores the complexity of managing ventilation in post-CA patients and highlights the need for ongoing research to refine these strategies for optimal patient outcomes.

Optimizing PEEP, plateau pressure, and driving pressure

PEEP is a crucial aspect of mechanical ventilation strategy, especially in the management of PCAS, yet research specifically addressing its optimal use in this patient population remains limited. The application of PEEP for patients with PCAS requires careful consideration, given its potential to influence both pulmonary and cerebral hemodynamics significantly. On one hand, high levels of PEEP can pose risks, such as diminished tissue oxygen delivery resulting from diminished venous return, circulatory impairment and elevated ICP. On the other hand, setting PEEP too low or employing zero PEEP might increase the likelihood of atelectasis and subsequent lung injury, complicating the patient’s recovery process [65, 66]. Sutherasan et al. have shown that higher VT, higher PPLAT, and lower PEEP in the first 24 h after ICU admission were associated with an increased risk of developing ARDS or pneumonia in patients initially without lung injury [44]. This emphasizes the need for careful ventilatory settings to prevent secondary lung complications. Thus, setting PEEP at ≥ 5 cmH2O is advisable to prevent atelectasis and protect against PALI, while also considering risks such as dynamic lung hyperinflation, circulatory depression, and brain damage [64, 67].

Plateau pressure (PPLAT) is a crucial measure in mechanical ventilation, representing the pressure in the airways at the end of inspiration without airflow, thus reflecting mean alveolar pressure without being influenced by airway resistance. Keeping PPLAT < 20 cmH2O is recommended to minimize mortality risk, especially in patients without ARDS. This is supported by a study in PCAS cohorts, where maintaining PPLAT < 20 cmH2O has been linked to better outcomes and reduced risk of barotrauma, a common complication after resuscitation [58]. PPLAT < 20 cmH2O may be difficult in post-cardiac arrest patients requiring higher PEEP levels.

Driving pressure (ΔP) is reflecting the stress exerted during the lung expansion, calculated as the difference between PPLAT and PEEP. A sub-analysis of the TTM1 trial reported a median ΔP of 14.7 cmH2O in patients with PCAS, with findings indicating that ΔP was an independent factor of higher mortality and adverse neurological outcomes [58]. However, ΔP does not consider respiratory rate, which itself can contribute to VALI, which is part of PALI [68]. Lowering ΔP might lead to increase PaCO2 due to reduced VT, necessitating a higher respiratory rate to maintain constant PaCO2 levels. For this reason, an equation incorporating both ΔP and respiratory rate (4 × ΔP + respiratory rate) was explored in patients with ARDS and found to strongly correlate with mortality [69]. This metric was also applied by Robba et al. in a cohort of post-CA patients, revealing a robust association with poor neurological outcomes and increased mortality [58]. Currently, it is suggested to keep the ΔP < 13 cmH2O by adjusting the VT and PEEP level according to the patient’s clinical picture, aiming to optimize lung-protective ventilation strategies [64].

Extra corporeal membrane oxygenation

The extra corporeal membrane oxygenation (ECMO) has been used an extension of CPR (extracorporeal CPR: ECPR) in recent years [70,71,72]. In addition to potentially improved survival rates with favorable neurological outcomes, ECMO is a valuable modality to minimize the risk of PALI, pulmonary congestion, and frequently exacerbated ventilatory support, which may interfere with lung protective ventilation discussed above. However, it must be noted that ECMO may exacerbate pulmonary congestion through aortic retrograde flow resulting in increased left ventricular afterload [73]. This can be mitigated by running ECMO at the lowest possible flow wares, implementing a percutaneous micro axial pump, or veno-arterial-venous ECMO configuration [74]. Despite the EOLIA trial’s controversial results, in the case of the development of ARDS, ECMO could be deployed in either veno-venous or veno-arterial configuration to allow for ventilation and oxygenation while the lungs are being rested [75].

Therapeutic hypothermia

Therapeutic hypothermia, inclusive of TTM, is the primary neuroprotective approach post-CA [76,77,78]. The efficacy of therapeutic hypothermia for lung injury, including ARDS, has been reported in both animal and human studies. In injury model such as pulmonary IR injury, pulmonary hypertension, VILI, smoking-induced injury, endotoxemia model, and hemorrhagic shock, therapeutic hypothermia has been reported to suppress lung injury by modulating inducible nitric oxide synthase (iNOS) production, endothelial nitric oxide synthase (eNOS) production, neutrophil activation, or adhesion molecule expression [79,80,81,82,83,84,85,86]. An animal study using a rabbit model of ALI has shown that mild therapeutic hypothermia with external cooling reduced lung inflammation and damage and improved oxygenation, likely by lowering levels of inflammatory cytokines, such as TNF-α, IL-6, and IL-8 [87]. In addition, in an experiment using pig models of oleic acid-induced ARDS, authors reported that the intervention of hypothermia at 32 °C reduced the pathological lung damage and improved lung mechanics [88]. A retrospective study of 58 patients with ARDS who received muscle relaxation and a pilot feasibility study of 8 patients with severe ARDS with P/F ratio < 150 showed that hypothermia (34–36 °C for 48 h) reduced in-hospital mortality (75% vs 53.4%, p = 0.26) and increased ventilator-free days, while not statistically significant [89]. Conversely, therapeutic hypothermia is associated with an increased risk of pneumonia, which could worsen PALI [90].

Wu et al. investigated the impact of therapeutic hypothermia on PALI using a swine model of CA [10]. In their study, hypothermic animals were cooled to 33 °C for 24 h post-resuscitation, then gradually rewarmed at 1 °C/h for 5 h, while normothermic animals were kept at 37–38 °C. Despite both groups exhibiting PALI, the hypothermia group showed significant improvements in ELWI, PVPI, and P/F ratio, indicating reduced lung injury. Although derived from limited animal research, these findings suggest therapeutic hypothermia could potentially be a viable treatment for PALI.

The Hypothermia After Cardiac Arrest (HACA) study [77] and a study by Bernard et al. [76] reported improved neurological prognosis and reduced mortality in patients with ventricular tachycardia or ventricular fibrillation who underwent therapeutic hypothermia, cooled to 32–34 °C, compared to those who were not cooled. These seminal studies have significantly influenced clinical practices in the management of post-CA patients. However, the TTM trial [78] found that hypothermia at 33 °C did not improve mortality or neurological outcomes in patients following OHCA when compared with normothermia at 37 °C. Subsequently, the HYPERION Trial reported a significant improvement in survival and neurological outcomes at 34 °C for patients with pulseless electrical activity or asystole [91]. Yet, the TTM2 Trial indicated no difference in neurological outcomes or mortality between temperatures of 33 °C for 24 h and 36 °C for 24 h [92], suggesting that the effectiveness of hypothermia in PCAS patients remains controversial. Notably, none of these RCTs provides clear evidence regarding the impact of hypothermia on lung function.

Factors associated with mitochondrial pathophysiology

Mitochondria plays an integral role in the development and onset of ALI. DAMPs are a collective term for numerous endogenous risk molecules present in the nucleus, mitochondria, or cytoplasm [93, 94], and mtDNA, as mitochondrial DAMPs, has been implicated in sepsis-induced increases lung endothelial cell permeability in ALI [95]. The presence of large amounts of ROS can upset the balance between mitochondrial dysfunction and mitosis, accelerating sepsis progression and indirectly causing ALI [96]. Thus, factors related to impaired mitochondrial pathophysiology may be potential therapeutic targets for PALI in patients with PCAS [97]. Mitochondria-targeted antioxidants can protect against ventilator-induced mitochondrial dysfunction and oxidative stress, suggesting improved outcomes for ALI treated by ventilators [98]. Furthermore, mitochondrial transplantation, as an emerging technology to replace damaged mitochondria with exogenous healthy mitochondria [99,100,101], can significantly improve lung status and reduce lung tissue damage caused by ALI [102]. Pang et al. showed that in an endotoxin-induced ALI rat model, allogeneic mitochondria administered via the jugular vein accumulated in the lungs, protecting the endothelium of alveolar capillary arrays, and improving gas exchange in the acute phase [103]. Moreover, Hayashida et al. showed that intravenous administration of allogeneic mitochondria immediately after ROSC improves the lung wet/dry ratio after resuscitation in a rat model of asphyxial CA [104]. However, since there is currently no clinically available bedside surrogate marker for mitochondrial dysfunction, further translational research is warranted to develop real-time measurement techniques for assessing mitochondrial damage.

Other therapeutic approaches

A Rho kinase (ROCK) is a type of protein kinase that plays a crucial role in cellular processes such as cell contraction, adhesion, motility, and transcriptional regulation. It is activated by the small GTPase RhoA and regulates the phosphorylation of myosin light chain, which affects the remodeling of the cell cytoskeleton. The Rho/ROCK signaling pathway also influences the expression of vascular endothelial-cadherin, which maintains endothelial junction stability, and intercellular adhesive molecule-1, which regulates leukocyte adhesion and transmigration. ROCK inhibition has been found to be effective in reducing damage caused by IR injury and preventing neutrophil recruitment and edema formation in ALI. Fasudil, a Rho kinase inhibitor, is currently used clinically to treat cerebral vasospasms and has shown promising safety profiles in various clinical trials for conditions such as angina, systemic and pulmonary hypertension, stroke, and heart failure. One study demonstrated that pretreatment with fasudil, a medication, can reduce lung injury caused by CA in rats [105]. Fasudil showed protective effects by decreasing lung edema, oxidative stress, and inflammation. These effects are believed to be mediated through the inhibition of the Rho/ROCK signaling pathway, which is known to be involved in lung IR injury.

Alda-1 is a compound that activates aldehyde dehydrogenase 2 (ALDH2), an enzyme involved in the removal of toxic aldehydic products. The specific agonist of ALDH2, Alda-1, has been shown to protect the lung against different stimuli in various experimental settings, such as acrolein-, hypoxia-, sepsis-, heatstroke-, severe hemorrhagic shock-induced lung injury, regional lung IR injury, and global IR injury [106,107,108,109,110,111]. One study aimed to investigate whether Alda-1 treatment could alleviate lung injury after CA/CPR in a swine model [112]. They found that Alda-1 improved lung function and reduced cell death through the inhibition of apoptosis and ferroptosis, suggesting its potential as a therapeutic approach for lung protection and enhance cell survival in PALI.

Future directions

An overview of PALI outline in our knowledge to date is summarized in Fig. 1. PALI is thought to be caused by a complex combination of factors associated with CA. The impact of each factor probably varies from the patient’s background, including underlying disease and duration of CA. On the other hand, the incidence and pathogenesis of PALI are gradually becoming clearer with the widespread use of rapid post-arrest CT scans and lung ultrasound. Although the severity of PALI varies, it has been reported that the presence of PALI affects the prognosis of patients after CA, and thus the treatment of PALI and prevention methods are expected to be studied [38, 47, 113,114,115].

Fig. 1
figure 1

A clinical outline of post-arrest lung injury

ARDS presents primarily as hypoxic respiratory failure, especially in the early acute phase. Systemic and brain tissue hypoxia are associated with worse outcomes in PCAS, and it has been reported that patients who develop ARDS after OHCA are less likely to recover neurologically and be discharged [38]. The association between ventilation at low tidal volume and improved outcomes after OHCA has been demonstrated, and palliation or risk reduction of ARDS may be an important treatment strategy for improving outcomes, including neurologically intact survival after CA [57]. Currently, the treatment of PALI is similar to that of ALI and ARDS, with appropriate ventilator settings in post-ROSC respiratory management being critical. In addition, therapeutic hypothermia has been reported to reduce lung injury in animal models as well as in clinical cases. Particularly, in PCAS patients with severe PALI, the reduction of lung injury by TTM may be more important than these side effects, so it is necessary to investigate the settings of TTM and patient criteria for selecting TTM for the treatment of PALI.

In PCAS, mitochondrial dysfunction manifests distinctly across different organs, influenced by their specific metabolic demands and stress responses [116]. In the lungs, increased oxidative stress and impaired mitochondrial respiration lead to the release of mtDNA, which acts as a DAMP, eliciting inflammatory responses that contribute to ALI. In the brain, mitochondrial dysfunction primarily involves extensive oxidative damage and impaired ATP production, leading to neuronal cell death and neurodegeneration. Cardiac mitochondria experience disrupted electron transport chain function, reduced ATP synthesis, and increased ROS production, resulting in oxidative damage and enhanced apoptosis. Renal mitochondrial alterations include impaired biogenesis and function, elevated oxidative stress, and altered dynamics affecting cellular homeostasis and survival.

The interaction of organs in PCAS is critical due to the interdependence of their functions and the systemic nature of the response to IR injury. Mitochondrial dysfunction in one organ can exacerbate dysfunction in others, creating a vicious cycle of damage. For example, acute lung injury (ALI) increases systemic inflammation and oxidative stress, worsening outcomes in the brain, heart, and kidneys. Understanding these interactions is essential for developing comprehensive treatment strategies that address multi-organ dysfunction in PCAS.

Improvement of mitochondrial function in patients with lung injury is thought to have the potential to improve prognosis as well as lung injury. In particular, mitochondrial transplantation could be a promising therapy to improve lung injury post-CA. However, while the use of animal models has shown that mitochondrial transplantation can accumulate in the injured lungs and reduce lung damage, there are a number of issues that need to be addressed before it can be applied clinically. These include the source of the mitochondria to be transplanted, the timing of the transplant, the indication, the dosage, and the frequency of mitochondrial transplantation. It is essential to develop translational studies to apply mitochondrial transplantation to clinical practice in particular, and it will be necessary to set conditions for clinical application based on these data.

Conclusions

PALI is a pathological condition that has a high overall incidence as a complication and affects the prognosis of patients after CA/CPR. Rapid detection of PALI is essential to ensure prompt etiologic therapy, and the use of diagnostic tools is mandatory. Early quantitative CT evaluation is important to improve the accuracy of clinical diagnosis, and the usefulness of LUS has been reported as a bedside assessment of lung injury. Supportive care for patients with PALI should be based on the need to maintain adequate oxygen and ventilator settings while reducing the potential for lung injury due to VILI or other causes. The clinical translational research on pharmacological approaches, including mitochondria-targeted drugs, remains extremely limited. Further research is needed to elucidate which patients benefit from therapeutic hypothermia.

Availability of data and materials

Not applicable.

Abbreviations

ALDH:

Aldehyde dehydrogenase 2

ALI:

Acute lung injury

ARDS:

Acute respiratory distress syndrome

CA:

Cardiac arrest

CPR:

Cardiopulmonary resuscitation

CT:

Computed tomography

DAMPs:

Damage-associated molecular patterns

ECMO:

Extra corporeal membrane oxygenation

EVLW:

Extravascular lung water

ICP:

Intracranial pressure

ICU:

Intensive care unit

IFN-γ:

Interferon-gamma

IL:

Interleukin

IR:

Ishcemia-reperfusion

LUS:

Lung ultrasound score

MCC:

Mechanical chest compression

mtDNA:

Mitochondrial DNA

OHCA:

Out-of-hospital cardiac arrest

PALI:

Post-arrest lung injury

PCAS:

Post-cardiac arrest syndrome

PEEP:

Positive end-expiratory pressure

PiCCO:

Pulse-induced contour cardiac output

P PLAT :

Plateu pressure

PVPI:

Pulmonary vascular permeability index

RCT:

Randomized controlled trial

ROCK:

Rho kinase

ROS:

Reactive oxygen species

ROSC:

Return of spontaneous circulation

TNF-α:

Tumor necrosis factor-alpha

TTM:

Target temperature management

VALI:

Ventilator-associated lung injury

VILI:

Ventilator-induced lung injury

ΔP :

Driving pressure

References

  1. Girotra S, Nallamothu BK, Spertus JA, Li Y, Krumholz HM, Chan PS, American Heart Association Get with the Guidelines-Resuscitation I. Trends in survival after in-hospital cardiac arrest. N Engl J Med. 2012;367(20):1912–20.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  2. Virani SS, Alonso A, Aparicio HJ, Benjamin EJ, Bittencourt MS, Callaway CW, Carson AP, Chamberlain AM, Cheng S, Delling FN, et al. Heart disease and stroke statistics-2021 update: a report from the American Heart Association. Circulation. 2021;143(8):e254–743.

    Article  PubMed  Google Scholar 

  3. Soar J, Donnino MW, Maconochie I, Aickin R, Atkins DL, Andersen LW, Berg KM, Bingham R, Bottiger BW, Callaway CW, et al. 2018 international consensus on cardiopulmonary resuscitation and emergency cardiovascular care science with treatment recommendations summary. Circulation. 2018;138(23):e714–30.

    Article  PubMed  Google Scholar 

  4. Grasner JT, Herlitz J, Tjelmeland IBM, Wnent J, Masterson S, Lilja G, Bein B, Bottiger BW, Rosell-Ortiz F, Nolan JP, et al. European resuscitation council guidelines 2021: epidemiology of cardiac arrest in Europe. Resuscitation. 2021;161:61–79.

    Article  PubMed  Google Scholar 

  5. Taccone F, Cronberg T, Friberg H, Greer D, Horn J, Oddo M, Scolletta S, Vincent JL. How to assess prognosis after cardiac arrest and therapeutic hypothermia. Crit Care. 2014;18(1):202.

    Article  PubMed  PubMed Central  Google Scholar 

  6. Stub D, Bernard S, Duffy SJ, Kaye DM. Post cardiac arrest syndrome: a review of therapeutic strategies. Circulation. 2011;123(13):1428–35.

    Article  PubMed  Google Scholar 

  7. Neumar RW, Nolan JP, Adrie C, Aibiki M, Berg RA, Bottiger BW, Callaway C, Clark RS, Geocadin RG, Jauch EC, et al. Post-cardiac arrest syndrome: epidemiology, pathophysiology, treatment, and prognostication. A consensus statement from the International Liaison Committee on Resuscitation (American Heart Association, Australian and New Zealand Council on Resuscitation, European Resuscitation Council, Heart and Stroke Foundation of Canada, InterAmerican Heart Foundation, Resuscitation Council of Asia, and the Resuscitation Council of Southern Africa); the American Heart Association Emergency Cardiovascular Care Committee; the Council on Cardiovascular Surgery and Anesthesia; the Council on Cardiopulmonary, Perioperative, and Critical Care; the Council on Clinical Cardiology; and the Stroke Council. Circulation. 2008;118(23):2452–83.

    Article  PubMed  Google Scholar 

  8. Hirsch KG, Abella BS, Amorim E, Bader MK, Barletta JF, Berg K, Callaway CW, Friberg H, Gilmore EJ, Greer DM, et al. Critical care management of patients after cardiac arrest: a scientific statement from the American Heart Association and Neurocritical Care Society. Circulation. 2024;40(1):1–37.

    Google Scholar 

  9. Johnson NJ, Town JA. Don’t go breaking my…lungs? The acute respiratory distress syndrome is common, deadly, and probably underrecognized after cardiac arrest. Resuscitation. 2022;177:1–2.

    Article  PubMed  PubMed Central  Google Scholar 

  10. Wu C, Xu J, Jin X, Chen Q, Li Z, Zhang M. Effect of mild hypothermia on lung injury after cardiac arrest in swine based on lung ultrasound. BMC Pulm Med. 2019;19(1):198.

    Article  PubMed  PubMed Central  Google Scholar 

  11. Magliocca A, Rezoagli E, Zani D, Manfredi M, De Giorgio D, Olivari D, Fumagalli F, Langer T, Avalli L, Grasselli G, et al. Cardiopulmonary resuscitation-associated lung edema (CRALE). A translational study. Am J Respir Crit Care Med. 2021;203(4):447–57.

    Article  PubMed  Google Scholar 

  12. Czerwinska-Jelonkiewicz K, Grand J, Tavazzi G, Sans-Rosello J, Wood A, Oleksiak A, Buszman P, Krysinski M, Sionis A, Hassager C, et al. Acute respiratory failure and inflammatory response after out-of-hospital cardiac arrest: results of the post-cardiac arrest syndrome (PCAS) pilot study. Eur Heart J Acute Cardiovasc Care. 2020;9(4_suppl):S110–21.

    Article  PubMed  Google Scholar 

  13. Cereda M, Xin Y, Goffi A, Herrmann J, Kaczka DW, Kavanagh BP, Perchiazzi G, Yoshida T, Rizi RR. Imaging the injured lung: mechanisms of action and clinical use. Anesthesiology. 2019;131(3):716–49.

    Article  PubMed  Google Scholar 

  14. Liu Z, Liu Q, Wu G, Li H, Wang Y, Chen R, Wen C, Ling Q, Yang Z, Tang W. Quantitative CT assessment of lung injury after successful cardiopulmonary resuscitation in a porcine cardiac arrest model of different downtimes. Quant Imaging Med Surg. 2018;8(9):946–56.

    Article  PubMed  PubMed Central  Google Scholar 

  15. Mai N, Miller-Rhodes K, Knowlden S, Halterman MW. The post-cardiac arrest syndrome: a case for lung–brain coupling and opportunities for neuroprotection. J Cereb Blood Flow Metab. 2019;39(6):939–58.

    Article  PubMed  PubMed Central  Google Scholar 

  16. Cho SH, Kim EY, Choi SJ, Kim YK, Sung YM, Choi HY, Cho J, Yang HJ. Multidetector CT and radiographic findings of lung injuries secondary to cardiopulmonary resuscitation. Injury. 2013;44(9):1204–7.

    Article  PubMed  Google Scholar 

  17. Cha KC, Kim YW, Kim HI, Kim OH, Cha YS, Kim H, Lee KH, Hwang SO. Parenchymal lung injuries related to standard cardiopulmonary resuscitation. Am J Emerg Med. 2017;35(1):117–21.

    Article  PubMed  Google Scholar 

  18. Jang SJ, Cha YK, Kim JS, Do HH, Bak SH, Kwack WG. Computed tomographic findings of chest injuries following cardiopulmonary resuscitation: more complications for prolonged chest compressions? Medicine. 2020;99(33): e21685.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  19. Ryu HM, Yoo JY, Kim SJ. Computed tomographic features of lung parenchyma over time after cariopulmonary resuscitation. J Korean Soc Radiol. 2019;80(4):8.

    Article  Google Scholar 

  20. Wicky S, Wintermark M, Schnyder P, Capasso P, Denys A. Imaging of blunt chest trauma. Eur Radiol. 2000;10(10):1524–38.

    Article  CAS  PubMed  Google Scholar 

  21. Radu RR, Kaserer A, Seifert B, Simmen HP, Ruetzler K, Spahn DR, Neuhaus V. Prevalence and in-hospital outcome of aspiration in out-of-hospital intubated trauma patients. Eur J Emerg Med. 2018;25(5):362–7.

    Article  PubMed  Google Scholar 

  22. Perbet S, Mongardon N, Dumas F, Bruel C, Lemiale V, Mourvillier B, Carli P, Varenne O, Mira JP, Wolff M, et al. Early-onset pneumonia after cardiac arrest: characteristics, risk factors and influence on prognosis. Am J Respir Crit Care Med. 2011;184(9):1048–54.

    Article  PubMed  Google Scholar 

  23. Knight BH. The significance of the postmortem discovery of gastric contents in the air passages. Forensic Sci. 1975;6(3):229–34.

    Article  CAS  PubMed  Google Scholar 

  24. Ruetzler K, Leung S, Chmiela M, Rivas E, Szarpak L, Khanna S, Mao G, Drake RL, Sessler DI, Turan A. Regurgitation and pulmonary aspiration during cardio-pulmonary resuscitation (CPR) with a laryngeal tube: a pilot crossover human cadaver study. PLoS ONE. 2019;14(2): e0212704.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  25. Virkkunen I, Ryynanen S, Kujala S, Vuori A, Piilonen A, Kaaria JP, Kahara V, Pettila V, Yli-Hankala A, Silfvast T. Incidence of regurgitation and pulmonary aspiration of gastric contents in survivors from out-of-hospital cardiac arrest. Acta Anaesthesiol Scand. 2007;51(2):202–5.

    Article  CAS  PubMed  Google Scholar 

  26. Virkkunen I, Kujala S, Ryynanen S, Vuori A, Pettila V, Yli-Hankala A, Silfvast T. Bystander mouth-to-mouth ventilation and regurgitation during cardiopulmonary resuscitation. J Intern Med. 2006;260(1):39–42.

    Article  CAS  PubMed  Google Scholar 

  27. Albert M, Herlitz J, Rawshani A, Ringh M, Claesson A, Djarv T, Nordberg P. Cardiac arrest after pulmonary aspiration in hospitalised patients: a national observational study. BMJ Open. 2020;10(3): e032264.

    Article  PubMed  PubMed Central  Google Scholar 

  28. Basu S, Nozari A, Liu XL, Rubertsson S, Wiklund L. Development of a novel biomarker of free radical damage in reperfusion injury after cardiac arrest. FEBS Lett. 2000;470(1):1–6.

    Article  CAS  PubMed  Google Scholar 

  29. de Perrot M, Liu M, Waddell TK, Keshavjee S. Ischemia–reperfusion-induced lung injury. Am J Respir Crit Care Med. 2003;167(4):490–511.

    Article  PubMed  Google Scholar 

  30. De Perrot M, Sekine Y, Fischer S, Waddell TK, McRae K, Liu M, Wigle DA, Keshavjee S. Interleukin-8 release during early reperfusion predicts graft function in human lung transplantation. Am J Respir Crit Care Med. 2002;165(2):211–5.

    Article  PubMed  Google Scholar 

  31. Ng CS, Wan S, Yim AP. Pulmonary ischaemia–reperfusion injury: role of apoptosis. Eur Respir J. 2005;25(2):356–63.

    Article  CAS  PubMed  Google Scholar 

  32. Faust HE, Reilly JP, Anderson BJ, Ittner CAG, Forker CM, Zhang P, Weaver BA, Holena DN, Lanken PN, Christie JD, et al. Plasma mitochondrial DNA levels are associated with ARDS in trauma and sepsis patients. Chest. 2020;157(1):67–76.

    Article  CAS  PubMed  Google Scholar 

  33. Zeng Z, Li D, Liu F, Zhou C, Shao Q, Ding C, Qing C, Wang X, Hu Z, Qian K. Mitochondrial DNA plays an important role in lung injury induced by sepsis. J Cell Biochem. 2019;120(5):8547–60.

    Article  CAS  PubMed  Google Scholar 

  34. Liu R, Xu F, Bi S, Zhao X, Jia B, Cen Y. Mitochondrial DNA-induced inflammatory responses and lung injury in thermal injury murine model: protective effect of cyclosporine-A. J Burn Care Res. 2019;40(3):355–60.

    Article  PubMed  Google Scholar 

  35. Gan L, Chen X, Sun T, Li Q, Zhang R, Zhang J, Zhong J. Significance of serum mtDNA concentration in lung injury induced by hip fracture. Shock. 2015;44(1):52–7.

    Article  CAS  PubMed  Google Scholar 

  36. Mao JY, Li DK, Zhang HM, Wang XT, Liu DW. Plasma mitochondrial DNA levels are associated with acute lung injury and mortality in septic patients. BMC Pulm Med. 2021;21(1):66.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  37. Long G, Gong R, Wang Q, Zhang D, Huang C. Role of released mitochondrial DNA in acute lung injury. Front Immunol. 2022;13: 973089.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  38. Johnson NJ, Caldwell E, Carlbom DJ, Gaieski DF, Prekker ME, Rea TD, Sayre M, Hough CL. The acute respiratory distress syndrome after out-of-hospital cardiac arrest: incidence, risk factors, and outcomes. Resuscitation. 2019;135:37–44.

    Article  PubMed  Google Scholar 

  39. Shih JA, Robertson HK, Issa MS, Grossestreuer AV, Donnino MW, Berg KM, Moskowitz A. Acute respiratory distress syndrome after in-hospital cardiac arrest. Resuscitation. 2022;177:78–84.

    Article  PubMed  PubMed Central  Google Scholar 

  40. Pagano A, Barazzone-Argiroffo C. Alveolar cell death in hyperoxia-induced lung injury. Ann N Y Acad Sci. 2003;1010:405–16.

    Article  CAS  PubMed  Google Scholar 

  41. Bhandari V. Molecular mechanisms of hyperoxia-induced acute lung injury. Front Biosci. 2008;13:6653–61.

    Article  CAS  PubMed  Google Scholar 

  42. Peberdy MA, Callaway CW, Neumar RW, Geocadin RG, Zimmerman JL, Donnino M, Gabrielli A, Silvers SM, Zaritsky AL, Merchant R, et al. Part 9: post-cardiac arrest care: 2010 American heart association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation. 2010;122(18 Suppl 3):S768-786.

    PubMed  Google Scholar 

  43. Beitler JR, Malhotra A, Thompson BT. Ventilator-induced lung injury. Clin Chest Med. 2016;37(4):633–46.

    Article  PubMed  PubMed Central  Google Scholar 

  44. Sutherasan Y, Penuelas O, Muriel A, Vargas M, Frutos-Vivar F, Brunetti I, Raymondos K, D’Antini D, Nielsen N, Ferguson ND, et al. Management and outcome of mechanically ventilated patients after cardiac arrest. Crit Care. 2015;19(1):215.

    Article  PubMed  PubMed Central  Google Scholar 

  45. Jafari D, Gandomi A, Makhnevich A, Qiu M, Rolston DM, Gottesman EP, Tsegaye A, Mayo PH, Stewart ME, Zhang M, et al. Trajectories of hypoxemia and pulmonary mechanics of COVID-19 ARDS in the NorthCARDS dataset. BMC Pulm Med. 2022;22(1):51.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  46. Davis K Jr, Johannigman JA, Johnson RC Jr, Branson RD. Lung compliance following cardiac arrest. Acad Emerg Med. 1995;2(10):874–8.

    Article  PubMed  Google Scholar 

  47. Kim JS, Kim YJ, Kim M, Ryoo SM, Sohn CH, Ahn S, Kim WY. Impact of lung compliance on neurological outcome in patients with acute respiratory distress syndrome following out-of-hospital cardiac arrest. J Clin Med. 2020;9(2):527.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  48. Katira BH, Engelberts D, Otulakowski G, Giesinger RE, Yoshida T, Post M, Kuebler WM, Connelly KA, Kavanagh BP. Abrupt deflation after sustained inflation causes lung injury. Am J Respir Crit Care Med. 2018;198(9):1165–76.

    Article  CAS  PubMed  Google Scholar 

  49. Lederer W, Mair D, Rabl W, Baubin M. Frequency of rib and sternum fractures associated with out-of-hospital cardiopulmonary resuscitation is underestimated by conventional chest X-ray. Resuscitation. 2004;60(2):157–62.

    Article  PubMed  Google Scholar 

  50. Volpicelli G, Elbarbary M, Blaivas M, Lichtenstein DA, Mathis G, Kirkpatrick AW, Melniker L, Gargani L, Noble VE, Via G, et al. International evidence-based recommendations for point-of-care lung ultrasound. Intensive Care Med. 2012;38(4):577–91.

    Article  PubMed  Google Scholar 

  51. Mongodi S, Santangelo E, De Luca D, Rovida S, Corradi F, Volpicelli G, Gargani L, Bouhemad B, Mojoli F. Quantitative lung ultrasound: time for a consensus? Chest. 2020;158(2):469–70.

    Article  PubMed  Google Scholar 

  52. Endo Y, Miyasho T, Endo K, Kawamura Y, Miyoshi K, Takegawa R, Tagami T, Becker LB, Hayashida K. Diagnostic value of transpulmonary thermodilution measurements for acute respiratory distress syndrome in a pig model of septic shock. J Transl Med. 2022;20(1):617.

    Article  PubMed  PubMed Central  Google Scholar 

  53. Zhao Z, Jiang L, Xi X, Jiang Q, Zhu B, Wang M, Xing J, Zhang D. Prognostic value of extravascular lung water assessed with lung ultrasound score by chest sonography in patients with acute respiratory distress syndrome. BMC Pulm Med. 2015;15:98.

    Article  PubMed  PubMed Central  Google Scholar 

  54. Agricola E, Bove T, Oppizzi M, Marino G, Zangrillo A, Margonato A, Picano E. “Ultrasound comet-tail images”: a marker of pulmonary edema: a comparative study with wedge pressure and extravascular lung water. Chest. 2005;127(5):1690–5.

    Article  PubMed  Google Scholar 

  55. Serpa Neto A, Cardoso SO, Manetta JA, Pereira VG, Esposito DC, Pasqualucci Mde O, Damasceno MC, Schultz MJ. Association between use of lung-protective ventilation with lower tidal volumes and clinical outcomes among patients without acute respiratory distress syndrome: a meta-analysis. JAMA. 2012;308(16):1651–9.

    Article  CAS  PubMed  Google Scholar 

  56. Harmon MBA, van Meenen DMP, van der Veen A, Binnekade JM, Dankiewicz J, Ebner F, Nielsen N, Pelosi P, Schultz MJ, Horn J, et al. Practice of mechanical ventilation in cardiac arrest patients and effects of targeted temperature management: a substudy of the targeted temperature management trial. Resuscitation. 2018;129:29–36.

    Article  PubMed  Google Scholar 

  57. Beitler JR, Ghafouri TB, Jinadasa SP, Mueller A, Hsu L, Anderson RJ, Joshua J, Tyagi S, Malhotra A, Sell RE, et al. Favorable neurocognitive outcome with low tidal volume ventilation after cardiac arrest. Am J Respir Crit Care Med. 2017;195(9):1198–206.

    Article  PubMed  PubMed Central  Google Scholar 

  58. Robba C, Badenes R, Battaglini D, Ball L, Brunetti I, Jakobsen JC, Lilja G, Friberg H, Wendel-Garcia PD, Young PJ, et al. Ventilatory settings in the initial 72 h and their association with outcome in out-of-hospital cardiac arrest patients: a preplanned secondary analysis of the targeted hypothermia versus targeted normothermia after out-of-hospital cardiac arrest (TTM2) trial. Intensive Care Med. 2022;48(8):1024–38.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  59. Nolan JP, Sandroni C, Bottiger BW, Cariou A, Cronberg T, Friberg H, Genbrugge C, Haywood K, Lilja G, Moulaert VRM, et al. European resuscitation council and European society of intensive care medicine guidelines 2021: post-resuscitation care. Intensive Care Med. 2021;47(4):369–421.

    Article  PubMed  PubMed Central  Google Scholar 

  60. Tiruvoipati R, Pilcher D, Botha J, Buscher H, Simister R, Bailey M. Association of hypercapnia and hypercapnic acidosis with clinical outcomes in mechanically ventilated patients with cerebral injury. JAMA Neurol. 2018;75(7):818–26.

    Article  PubMed  PubMed Central  Google Scholar 

  61. Eastwood GM, Schneider AG, Suzuki S, Peck L, Young H, Tanaka A, Martensson J, Warrillow S, McGuinness S, Parke R, et al. Targeted therapeutic mild hypercapnia after cardiac arrest: a phase II multi-centre randomised controlled trial (the CCC trial). Resuscitation. 2016;104:83–90.

    Article  PubMed  Google Scholar 

  62. Jakkula P, Reinikainen M, Hastbacka J, Loisa P, Tiainen M, Pettila V, Toppila J, Lahde M, Backlund M, Okkonen M, et al. Targeting two different levels of both arterial carbon dioxide and arterial oxygen after cardiac arrest and resuscitation: a randomised pilot trial. Intensive Care Med. 2018;44(12):2112–21.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  63. Eastwood G, Nichol AD, Hodgson C, Parke RL, McGuinness S, Nielsen N, Bernard S, Skrifvars MB, Stub D, Taccone FS, et al. Mild hypercapnia or normocapnia after out-of-hospital cardiac arrest. N Engl J Med. 2023;389(1):45–57.

    Article  CAS  PubMed  Google Scholar 

  64. Battaglini D, Pelosi P, Robba C. Ten rules for optimizing ventilatory settings and targets in post-cardiac arrest patients. Crit Care. 2022;26(1):390.

    Article  PubMed  PubMed Central  Google Scholar 

  65. Farias LL, Faffe DS, Xisto DG, Santana MC, Lassance R, Prota LF, Amato MB, Morales MM, Zin WA, Rocco PR. Positive end-expiratory pressure prevents lung mechanical stress caused by recruitment/derecruitment. J Appl Physiol. 2005;98(1):53–61.

    Article  PubMed  Google Scholar 

  66. Ajith Kumar AK, Anjum F. Ventilator-induced lung injury (VILI). In: StatPearls. Treasure Island: StatPearls Publishing; 2023.

    Google Scholar 

  67. Robba C, Poole D, McNett M, Asehnoune K, Bosel J, Bruder N, Chieregato A, Cinotti R, Duranteau J, Einav S, et al. Mechanical ventilation in patients with acute brain injury: recommendations of the European Society of Intensive Care Medicine consensus. Intensive Care Med. 2020;46(12):2397–410.

    Article  PubMed  PubMed Central  Google Scholar 

  68. Protti A, Maraffi T, Milesi M, Votta E, Santini A, Pugni P, Andreis DT, Nicosia F, Zannin E, Gatti S, et al. Role of strain rate in the pathogenesis of ventilator-induced lung edema. Crit Care Med. 2016;44(9):e838-845.

    Article  PubMed  Google Scholar 

  69. Costa ELV, Slutsky AS, Brochard LJ, Brower R, Serpa-Neto A, Cavalcanti AB, Mercat A, Meade M, Morais CCA, Goligher E, et al. Ventilatory variables and mechanical power in patients with acute respiratory distress syndrome. Am J Respir Crit Care Med. 2021;204(3):303–11.

    Article  PubMed  Google Scholar 

  70. Belohlavek J, Smalcova J, Rob D, Franek O, Smid O, Pokorna M, Horak J, Mrazek V, Kovarnik T, Zemanek D, et al. Effect of intra-arrest transport, extracorporeal cardiopulmonary resuscitation, and immediate invasive assessment and treatment on functional neurologic outcome in refractory out-of-hospital cardiac arrest: a randomized clinical trial. JAMA. 2022;327(8):737–47.

    Article  PubMed  PubMed Central  Google Scholar 

  71. Suverein MM, Delnoij TSR, Lorusso R, Brandon Bravo Bruinsma GJ, Otterspoor L, Elzo Kraemer CV, Vlaar APJ, van der Heijden JJ, Scholten E, den Uil C, et al. Early extracorporeal CPR for refractory out-of-hospital cardiac arrest. N Engl J Med. 2023;388(4):299–309.

    Article  PubMed  Google Scholar 

  72. Yannopoulos D, Bartos J, Raveendran G, Walser E, Connett J, Murray TA, Collins G, Zhang L, Kalra R, Kosmopoulos M, et al. Advanced reperfusion strategies for patients with out-of-hospital cardiac arrest and refractory ventricular fibrillation (ARREST): a phase 2, single centre, open-label, randomised controlled trial. Lancet. 2020;396(10265):1807–16.

    Article  PubMed  PubMed Central  Google Scholar 

  73. Koziol KJ, Isath A, Rao S, Gregory V, Ohira S, Van Diepen S, Lorusso R, Krittanawong C. Extracorporeal membrane oxygenation (VA-ECMO) in management of cardiogenic shock. J Clin Med. 2023;12(17):5576.

    Article  PubMed  PubMed Central  Google Scholar 

  74. Lusebrink E, Orban M, Kupka D, Scherer C, Hagl C, Zimmer S, Luedike P, Thiele H, Westermann D, Massberg S, et al. Prevention and treatment of pulmonary congestion in patients undergoing venoarterial extracorporeal membrane oxygenation for cardiogenic shock. Eur Heart J. 2020;41(38):3753–61.

    Article  PubMed  Google Scholar 

  75. Combes A, Hajage D, Capellier G, Demoule A, Lavoue S, Guervilly C, Da Silva D, Zafrani L, Tirot P, Veber B, et al. Extracorporeal membrane oxygenation for severe acute respiratory distress syndrome. N Engl J Med. 2018;378(21):1965–75.

    Article  PubMed  Google Scholar 

  76. Bernard SA, Gray TW, Buist MD, Jones BM, Silvester W, Gutteridge G, Smith K. Treatment of comatose survivors of out-of-hospital cardiac arrest with induced hypothermia. N Engl J Med. 2002;346(8):557–63.

    Article  PubMed  Google Scholar 

  77. Hypothermia after Cardiac Arrest Study Group. Mild therapeutic hypothermia to improve the neurologic outcome after cardiac arrest. N Engl J Med. 2002;346(8):549–56.

    Article  Google Scholar 

  78. Nielsen N, Wetterslev J, Cronberg T, Erlinge D, Gasche Y, Hassager C, Horn J, Hovdenes J, Kjaergaard J, Kuiper M, et al. Targeted temperature management at 33 degrees C versus 36 degrees C after cardiac arrest. N Engl J Med. 2013;369(23):2197–206.

    Article  CAS  PubMed  Google Scholar 

  79. Chiang CH, Wu K, Yu CP, Yan HC, Perng WC, Wu CP. Hypothermia and prostaglandin E(1) produce synergistic attenuation of ischemia–reperfusion lung injury. Am J Respir Crit Care Med. 1999;160(4):1319–23.

    Article  CAS  PubMed  Google Scholar 

  80. Huang PS, Tang GJ, Chen CH, Kou YR. Whole-body moderate hypothermia confers protection from wood smoke-induced acute lung injury in rats: the therapeutic window. Crit Care Med. 2006;34(4):1160–7.

    Article  PubMed  Google Scholar 

  81. Kira S, Daa T, Kashima K, Mori M, Noguchi T, Yokoyama S. Mild hypothermia reduces expression of intercellular adhesion molecule-1 (ICAM-1) and the accumulation of neutrophils after acid-induced lung injury in the rat. Acta Anaesthesiol Scand. 2005;49(3):351–9.

    Article  CAS  PubMed  Google Scholar 

  82. Lim CM, Hong SB, Koh Y, Lee SD, Kim WS, Kim DS, Kim WD. Hypothermia attenuates vascular manifestations of ventilator-induced lung injury in rats. Lung. 2003;181(1):23–34.

    Article  PubMed  Google Scholar 

  83. Lim CM, Kim MS, Ahn JJ, Kim MJ, Kwon Y, Lee I, Koh Y, Kim DS, Kim WD. Hypothermia protects against endotoxin-induced acute lung injury in rats. Intensive Care Med. 2003;29(3):453–9.

    Article  PubMed  Google Scholar 

  84. Scumpia PO, Sarcia PJ, DeMarco VG, Stevens BR, Skimming JW. Hypothermia attenuates iNOS, CAT-1, CAT-2, and nitric oxide expression in lungs of endotoxemic rats. Am J Physiol Lung Cell Mol Physiol. 2002;283(6):L1231-1238.

    Article  CAS  PubMed  Google Scholar 

  85. Suzuki S, Hotchkiss JR, Takahashi T, Olson D, Adams AB, Marini JJ. Effect of core body temperature on ventilator-induced lung injury. Crit Care Med. 2004;32(1):144–9.

    Article  PubMed  Google Scholar 

  86. Zhang L, Kumar S, Kaminski A, Kasch C, Sponholz C, Stamm C, Ladilov Y, Steinhoff G. Importance of endothelial nitric oxide synthase for the hypothermic protection of lungs against ischemia–reperfusion injury. J Thorac Cardiovasc Surg. 2006;131(5):969–74.

    Article  CAS  PubMed  Google Scholar 

  87. Akyol O, Demirgan S, Sengelen A, Guneyli HC, Oran DS, Yildirim F, Haktanir D, Sevdi MS, Erkalp K, Selcan A. Mild hypothermia via external cooling improves lung function and alleviates pulmonary inflammatory response and damage in two-hit rabbit model of acute lung injury. J Invest Surg. 2022;35(7):1472–83.

    Article  PubMed  Google Scholar 

  88. Angus SA, Henderson WR, Banoei MM, Molgat-Seon Y, Peters CM, Parmar HR, Griesdale DEG, Sekhon M, Sheel AW, Winston BW, et al. Therapeutic hypothermia attenuates physiologic, histologic, and metabolomic markers of injury in a porcine model of acute respiratory distress syndrome. Physiol Rep. 2022;10(9): e15286.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  89. Slack DF, Corwin DS, Shah NG, Shanholtz CB, Verceles AC, Netzer G, Jones KM, Brown CH, Terrin ML, Hasday JD. Pilot feasibility study of therapeutic hypothermia for moderate to severe acute respiratory distress syndrome. Crit Care Med. 2017;45(7):1152–9.

    Article  PubMed  PubMed Central  Google Scholar 

  90. Geurts M, Macleod MR, Kollmar R, Kremer PH, van der Worp HB. Therapeutic hypothermia and the risk of infection: a systematic review and meta-analysis. Crit Care Med. 2014;42(2):231–42.

    Article  PubMed  Google Scholar 

  91. Lascarrou JB, Merdji H, Le Gouge A, Colin G, Grillet G, Girardie P, Coupez E, Dequin PF, Cariou A, Boulain T, et al. Targeted temperature management for cardiac arrest with nonshockable rhythm. N Engl J Med. 2019;381(24):2327–37.

    Article  PubMed  Google Scholar 

  92. Dankiewicz J, Cronberg T, Lilja G, Jakobsen JC, Levin H, Ullen S, Rylander C, Wise MP, Oddo M, Cariou A, et al. Hypothermia versus normothermia after out-of-hospital cardiac arrest. N Engl J Med. 2021;384(24):2283–94.

    Article  PubMed  Google Scholar 

  93. Bianchi ME. DAMPs, PAMPs and alarmins: all we need to know about danger. J Leukoc Biol. 2007;81(1):1–5.

    Article  CAS  PubMed  Google Scholar 

  94. Venereau E, Ceriotti C, Bianchi ME. DAMPs from cell death to new life. Front Immunol. 2015;6:422.

    Article  PubMed  PubMed Central  Google Scholar 

  95. Sun S, Sursal T, Adibnia Y, Zhao C, Zheng Y, Li H, Otterbein LE, Hauser CJ, Itagaki K. Mitochondrial DAMPs increase endothelial permeability through neutrophil dependent and independent pathways. PLoS ONE. 2013;8(3): e59989.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  96. Gonzalez AS, Elguero ME, Finocchietto P, Holod S, Romorini L, Miriuka SG, Peralta JG, Poderoso JJ, Carreras MC. Abnormal mitochondrial fusion–fission balance contributes to the progression of experimental sepsis. Free Radic Res. 2014;48(7):769–83.

    Article  CAS  PubMed  Google Scholar 

  97. Supinski GS, Schroder EA, Callahan LA. Mitochondria and critical illness. Chest. 2020;157(2):310–22.

    Article  CAS  PubMed  Google Scholar 

  98. Powers SK, Hudson MB, Nelson WB, Talbert EE, Min K, Szeto HH, Kavazis AN, Smuder AJ. Mitochondria-targeted antioxidants protect against mechanical ventilation-induced diaphragm weakness. Crit Care Med. 2011;39(7):1749–59.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  99. Hayashida K, Takegawa R, Shoaib M, Aoki T, Choudhary RC, Kuschner CE, Nishikimi M, Miyara SJ, Rolston DM, Guevara S, et al. Mitochondrial transplantation therapy for ischemia reperfusion injury: a systematic review of animal and human studies. J Transl Med. 2021;19(1):214.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  100. McCully JD, Cowan DB, Emani SM, Del Nido PJ. Mitochondrial transplantation: from animal models to clinical use in humans. Mitochondrion. 2017;34:127–34.

    Article  CAS  PubMed  Google Scholar 

  101. Aoki T, Endo Y, Nakamura E, Kuschner CE, Kazmi J, Singh P, Yin T, Becker LB, Hayashida K. Therapeutic potential of mitochondrial transplantation in modulating immune responses post-cardiac arrest: a narrative review. J Transl Med. 2024;22(1):230.

    Article  PubMed  PubMed Central  Google Scholar 

  102. Moskowitzova K, Orfany A, Liu K, Ramirez-Barbieri G, Thedsanamoorthy JK, Yao R, Guariento A, Doulamis IP, Blitzer D, Shin B, et al. Mitochondrial transplantation enhances murine lung viability and recovery after ischemia–reperfusion injury. Am J Physiol Lung Cell Mol Physiol. 2020;318(1):L78–88.

    Article  CAS  PubMed  Google Scholar 

  103. Pang YL, Fang SY, Cheng TT, Huang CC, Lin MW, Lam CF, Chen KB. Viable allogeneic mitochondria transplantation improves gas exchange and alveolar-capillary permeability in rats with endotoxin-induced acute lung injuries. Int J Med Sci. 2022;19(6):1036–46.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  104. Hayashida K, Takegawa R, Endo Y, Yin T, Choudhary RC, Aoki T, Nishikimi M, Murao A, Nakamura E, Shoaib M, et al. Exogenous mitochondrial transplantation improves survival and neurological outcomes after resuscitation from cardiac arrest. BMC Med. 2023;21(1):56.

    Article  PubMed  PubMed Central  Google Scholar 

  105. Wei J, Wang P, Li Y, Dou Q, Lin J, Tao W, Lin J, Fu X, Huang Z, Zhang W. Inhibition of RHO kinase by fasudil attenuates ischemic lung injury after cardiac arrest in rats. Shock. 2018;50(6):706–13.

    Article  CAS  PubMed  Google Scholar 

  106. Hua T, Yang M, Zhou Y, Chen L, Wu H, Liu R. Alda-1 prevents pulmonary epithelial barrier dysfunction following severe hemorrhagic shock through clearance of reactive aldehydes. Biomed Res Int. 2019;2019:2476252.

    Article  PubMed  PubMed Central  Google Scholar 

  107. Ikeda T, Takahashi T, Tsujita M, Kanazawa M, Toriyabe M, Koyama M, Itoh K, Nakada T, Nishizawa M, Shimohata T. Effects of Alda-1, an aldehyde dehydrogenase-2 agonist, on hypoglycemic neuronal death. PLoS ONE. 2015;10(6): e0128844.

    Article  PubMed  PubMed Central  Google Scholar 

  108. Ling M, Huang C, Hua T, Li H, Xiao W, Lu Z, Jia D, Zhou W, Zhang L, Yang M. Acetaldehyde dehydrogenase 2 activation attenuates sepsis-induced brain injury through NLRP3 inflammasome regulation. Brain Res Bull. 2023;194:128–38.

    Article  CAS  PubMed  Google Scholar 

  109. Lu Q, Mundy M, Chambers E, Lange T, Newton J, Borgas D, Yao H, Choudhary G, Basak R, Oldham M, et al. Alda-1 protects against acrolein-induced acute lung injury and endothelial barrier dysfunction. Am J Respir Cell Mol Biol. 2017;57(6):662–73.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  110. Tsai HY, Hsu YJ, Lu CY, Tsai MC, Hung WC, Chen PC, Wang JC, Hsu LA, Yeh YH, Chu P, et al. Pharmacological activation of aldehyde dehydrogenase 2 protects against heatstroke-induced acute lung injury by modulating oxidative stress and endothelial dysfunction. Front Immunol. 2021;12: 740562.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  111. Zhou T, Wang X, Wang K, Lin Y, Meng Z, Lan Q, Jiang Z, Chen J, Lin Y, Liu X, et al. Activation of aldehyde dehydrogenase-2 improves ischemic random skin flap survival in rats. Front Immunol. 2023;14:1127610.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  112. Wu H, Xu S, Diao M, Wang J, Zhang G, Xu J. Alda-1 treatment alleviates lung injury after cardiac arrest and resuscitation in swine. Shock. 2022;58(5):464–9.

    Article  CAS  PubMed  Google Scholar 

  113. Eastwood GM, Tanaka A, Espinoza ED, Peck L, Young H, Martensson J, Zhang L, Glassford NJ, Hsiao YF, Suzuki S, et al. Conservative oxygen therapy in mechanically ventilated patients following cardiac arrest: a retrospective nested cohort study. Resuscitation. 2016;101:108–14.

    Article  PubMed  Google Scholar 

  114. Gajic O, Dara SI, Mendez JL, Adesanya AO, Festic E, Caples SM, Rana R, St Sauver JL, Lymp JF, Afessa B, et al. Ventilator-associated lung injury in patients without acute lung injury at the onset of mechanical ventilation. Crit Care Med. 2004;32(9):1817–24.

    Article  PubMed  Google Scholar 

  115. Ruemmler R, Ziebart A, Moellmann C, Garcia-Bardon A, Kamuf J, Kuropka F, Duenges B, Hartmann EK. Ultra-low tidal volume ventilation—a novel and effective ventilation strategy during experimental cardiopulmonary resuscitation. Resuscitation. 2018;132:56–62.

    Article  PubMed  Google Scholar 

  116. Nakamura E, Aoki T, Endo Y, Kazmi J, Hagiwara J, Kuschner CE, Yin T, Kim J, Becker LB, Hayashida K. Organ-specific mitochondrial alterations following ischemia–reperfusion injury in post-cardiac arrest syndrome: a comprehensive review. Life. 2024;14(4):477.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

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Concept and design: KH. Drafting manuscript: YE. Acquisition and interpretation of the data: TA, EN, JH, KI, CEK. Critical revision of the manuscript: DJ, DMR, LBB, KH. All authors have read and approved the manuscript.

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Correspondence to Kei Hayashida.

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Endo, Y., Aoki, T., Jafari, D. et al. Acute lung injury and post-cardiac arrest syndrome: a narrative review. j intensive care 12, 32 (2024). https://doiorg.publicaciones.saludcastillayleon.es/10.1186/s40560-024-00745-z

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