Abstract
Background and Objective: Acute respiratory distress syndrome (ARDS) is a severe, life-threatening medical condition characterized by poor oxygenation due to non-compliant lungs secondary diffuse alveolar damage. Encouragingly, the incidence of ARDS has declined steadily recently, attributed mainly to implementation of keystone guidelines and continuous research efforts. Mechanical ventilation is the cornerstone of supportive care for ARDS patients. This review aims to consolidate the current knowledge on pneumothorax (PNX) and pneumomediastinum (PMD) and to enhance the understanding of the readers. The objectives are to (I) explore the etiology and risk factors of PNX and PMD, (II) discuss the various diagnostic modalities available, (III) evaluate management options, and (IV) recent advancements.
Methods: A search of the literature was conducted using PubMed, MEDLINE, and Google Scholar for relevant articles pertaining to PNX and PMD in ARDS population. The clinical presentation, diagnostic and management strategies of PNX, PMD, and ARDS were summarized, and all authors reviewed the selection and decide which studies to include.
Key Content and Findings: The adoption of lung-protective ventilation strategies, based on the review of literature from the recent years, shows that it has played a significant role in reducing the occurrence of barotrauma, such as PNX and PMD. However, PNX and PMD remains to be a challenging complication to manage. With a specific focus on PNX and PMD, this review provides valuable insights into effectively managing and understanding these critical complications among ARDS patients.
Conclusions: ARDS, with its evolving definition, continues to pose a life-threatening threat. Despite the widespread adoption of lung-protective ventilation strategies, PNX and PMD present persistent challenges in management. Further research is imperative to enhance the risk assessment of ARDS patients prone to developing PNX and PMD and to institute more effective prevention and treatment measures.
Key Points
- Lung-Protective Ventilation and Barotrauma Prevention: While lung-protective ventilation strategies have decreased ARDS-related barotrauma, PNX and PMD remain complications due to alveolar rupture from high airway pressures and heterogeneous lung compliance.
- Pathophysiology of PNX and PMD in ARDS: The mechanisms underlying PNX and PMD involve alveolar overdistension, air dissection along bronchovascular sheaths, and structural lung fragility exacerbated by inflammation. The Macklin effect describes air migration from ruptured alveoli to the mediastinum, leading to PMD.
- Incidence and Risk Factors: The incidence of PNX and PMD in ARDS is influenced by ventilator settings, underlying lung pathology, and procedural interventions. The COVID-19 pandemic saw a rise in barotrauma incidence, likely due to heightened lung inflammation and ventilator-induced injury.
- Clinical Presentation and Diagnostic Modalities: Patients with PNX and PMD often present with acute respiratory distress, hemodynamic instability, and ventilator asynchrony. Diagnostic tools include chest radiography, CT imaging, and point-of-care ultrasound (POCUS), with ultrasound proving especially useful in critical care settings.
- Ventilator Strategies to Minimize Barotrauma: Adjusting ventilator parameters such as tidal volume, driving pressure, and PEEP to maintain lung protective conditions can reduce barotrauma risk. Novel strategies, including high-frequency ventilation and extracorporeal membrane oxygenation (ECMO), may further mitigate ventilator-induced lung injury.
- Management of PNX and PMD in ARDS Patients: Treatment approaches vary based on severity. Conservative management with high-flow oxygen is effective for small, stable air leaks, while larger pneumothoraces require chest tube drainage. Persistent leaks may necessitate surgical intervention such as pleurodesis or thoracoscopic repair.
- Role of Neuromuscular Blockade and Adjunctive Therapies: The use of neuromuscular blocking agents, such as cisatracurium, has been associated with reduced barotrauma in ARDS patients by limiting excessive respiratory effort and ventilator dyssynchrony.
- Prognostic Implications of PNX and PMD: The development of PNX or PMD in ARDS patients is linked to increased ICU length of stay, mechanical ventilation duration, and mortality. Timely identification and management are critical to improving outcomes.
- Barotrauma in COVID-19 ARDS: SARS-CoV-2-related ARDS demonstrated higher rates of PNX and PMD, likely due to a combination of viral-induced lung damage, hyperinflammation, and prolonged ventilator dependence. This highlights the need for individualized ventilation strategies in viral pneumonia-associated ARDS.
- Future Directions in ARDS Management: Research should focus on refining predictive algorithms for barotrauma risk stratification, optimizing lung-protective ventilation techniques, and integrating real-time monitoring tools such as artificial intelligence-assisted imaging for early detection of air leaks.
