A practical approach to the use of prone therapy in acute respiratory distress syndrome

Abstract

In this article we propose a practical approach to the use of prone therapy for acute respiratory distress syndrome (ARDS). We have attempted to provide information to improve the understanding and implementation of prone therapy based on the literature available and our own experience. We review the basic physiology behind ARDS and the theoretical mechanism by which prone therapy can be of benefit. The findings of the most significant studies regarding prone therapy in ARDS as they pertain to its implementation are summarized. Also provided is a discussion of the nuances of utilizing prone therapy, including potential pitfalls, complications, and contraindications. The specific considerations of prone therapy in open abdomens and traumatic brain injuries are discussed as well. Finally, we supply suggested protocols for the implementation of prone therapy discussing criteria for initiation and cessation of therapy as well as addressing issues such as the use of neuromuscular blockade and nutritional supplementation.

Keywords::

• acute respiratory distress syndrome
• critical care
• mechanical ventilation
• prone position
• refractory hypoxemia

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending or royalties.

No writing assistance was utilized in the production of this manuscript.

Key issues

• Acute respiratory distress syndrome (ARDS) is an inhomogeneous lung process that is associated with a variety of clinical states and has a high mortality. The criteria for ARDS have been updated with the 2011 Berlin definition of ARDS.

• The mainstay of treatment for ARDS is lung protective ventilation with low tidal volumes and positive end-expiratory pressure sufficient for alveolar recruitment. In patient with severe ARDS, prone positioning is the only therapeutic adjunct that has been shown to alter pulmonary pathophysiology and improve outcome.

• Early studies of prone positioning in the treatment of ARDS showed that despite increases in oxygenation, there was little improvement in overall survival; however, improvement in patient selection, implementation of lung protective ventilator strategies and extended duration of prone positioning have demonstrated improved outcomes in patients with severe ARDS.

• Prone positioning should be considered in patients with severe ARDS (PaO₂/FiO₂ <150) who remain hypoxic despite lung recruitment, maximizing positive end-expiratory pressure and adhering to lung protective ventilator strategies.

• The prone positioning should be maintained for at least 16 h daily, with longer durations of prone positioning demonstrating more favorable outcomes. Such protocols should be weighed against the risks of pressure ulcers, tube migration/dysfunction and increased intracranial pressure.

• Complications of prone positioning can include tube malfunction during proning, intolerance of gastric tube feeds, pressure related soft tissue and skin injuries, ocular injuries and increased intracranial pressure. Elevation of the head of the bed while the patient is prone may decrease the risk of these complications.

• Prone positioning should be discontinued once adequate oxygenation can be maintained on standard ventilator settings, if there is no improvement with prone positioning, or the patient becomes hemodynamically unstable.

• The use of prone positioning protocols should be tailored to meet individual patient needs while minimizing the potential for complications.