Prehospital systems often implement procedures, practices and equipment that change medicine and encourage hospitals to adopt and continue them throughout the patient care treatment cycle.
In this treatment-impact episode of The EMS Today Show, JEMS Editor Emeritus A.J. Heightman moderates an outstanding panel of experts who point out that prone positioning of patients is now shown to be one of those procedures. Proning is easy to do, requires no special equipment and can dramatically improve a patient’s oxygen saturation levels.
David A. Farcy MD, FAAEM, FACEP, FCCM, president of the American Academy of Emergency Medicine and chairman, Department of Emergency Medicine and Director, Emergency Medicine Critical Care at Mount Sinai Medical Center and Hildebrandt Emergency Center in Miami Beach, Florida. Dr. Farcy explains patient proning, its history in the treatment of ARDS and the finding that it is extremely effective in the care of patients suffering from COVID-19 infection.
He stresses that proning has been found to take awake, alert patients presenting as “Happy Hypoxic”. This is defined as being awake but presenting with low pulse oximetry levels that, would cause providers to intubate the patient in the past. With nasal or face mask oxygen, their O2 saturation levels were raised up from 88 to 94 (for example), keeping them from being intubated and, in some cases, being placed on ventilators.
Kenneth A Scheppke, MD, FAEMS, FAAEM, State EMS Medical Director, Florida Department of Health and chief medical officer, Palm Beach County Fire Rescue, explains that after review of the research on patient proning, he implemented it in the Palm Beach County Fire Rescue patient care treatment protocols. He found that it a very effective treatment procedure in their care of COVID-19 patients.
E. Reed Smith, MD, FACEP, Operational Medical Director for the Arlington County Fire and Police Department and Associate Professor of Emergency Medicine at The George Washington University School of Medicine, explained the Arlington County Fire Department’s Protocol for the Management of Respiratory Distress in COVID-19 unstable patients and how effective it has been in the care of conscious, alert patients whose pulse oximetry reading indicates they are on their way to “crashing.”
If the patient cannot lay comfortably prone, they place/secure the patient on their side (in a position of comfort), explain the importance of that position to each patient, and transport them to the ED in that position. It is important to note that, like other prehospital care innovations, Dr. Smith and the Arlington County EMS providers are explaining the prone and semi-prone positioning and its positive impact on the patient’s oxygen saturation – and they therefore continue that approach in the ED/Hospital. A copy of the Arlington County Fire protocol can be viewed and downloaded by clicking the download button below.
David E. Slattery, MD, FACEP, FAEMS, EMS Medical Director for Las Vegas Fire & Rescue and Professor and Director of Research in the Department of Emergency Medicine and the UNLV School of Medicine, reported that Las Vegas Fire & Rescue will be implementing pone positioning (patient rotation) procedures soon. A link to their training video can be found here.
Research on Prone Position in Patients With Acute Respiratory Distress Syndrome Prone position in patients with acute respiratory distress syndrome
1) Prone position in patients with acute respiratory distress syndrome
Rev Bras Ter Intensiva. 2016 Oct-Dec; 28(4): 452—462.
PMID: 27925054 https://www.ncbi.nlm.nih.gov/pubmed/27925054
2) Does prone positioning improve oxygenation and reduce mortality in patients with acute respiratory distress syndrome?
Can Respir J. 2014 Jul-Aug; 21(4): 213—215.
3) Prone ventilation for adult patients with acute respiratory distress syndrome
Official reprint from UpToDate®
www.uptodate.com ©2020 Up
4) A Comprehensive Review of Prone Position in ARDS
American Association for Respiratory Care
Respiratory Care November 2015, 60 (11) 1660-1687; DOI:
5) Effect of Prone Positioning on the Survival of Patients with Acute Respiratory Failure
695 Citing Articles
Excerpts from Reference #1 above: Prone position in patients with acute respiratory distress syndrome; Rev Bras Ter Intensiva. 2016 Oct-Dec; 28(4): 452—462.
- Patients with acute respiratory distress syndrome, especially the most severe cases, often present with refractory hypoxemia due to shunt, which can require additional treatments beyond mechanical ventilation, among which is mechanical ventilation in the prone position. This method, first recommended to improve oxygenation in 1974, can be easily implemented in any intensive care unit with trained personnel.
- Prone position has extremely robust bibliographic support. Various randomized clinical studies have demonstrated the effect of prone decubitus on the oxygenation of patients with acute respiratory distress syndrome measured in terms of the PaO2/FiO2 ratio, including its effects on increasing patient survival.
- Patients with ARDS, especially the most severely affected, often present with refractory hypoxemia due to shunt, which can require additional treatments beyond MV, including MV in the prone position (PP). This method, first recommended to improve oxygenation in 1974,(9) is easily implemented in any ICU(10) and has extremely robust bibliographic support. Various randomized clinical trials (RCTs) have demonstrated the beneficial effect of PP on the oxygenation of patients with ARDS,(11,12) including its effects on increasing patient survival. (11-14)
- In the lungs of patients with ARDS, alveoli in relatively normal condition coexist with others that are collapsed but recruitable, together with other non-recruitable alveolar sectors. This situation produces an increase in lung weight due to edema, generating over-pressure four to five times greater than normal, which precipitates collapse of the most dependent lung regions (compression atelectasis) and increased distension of non-dependent regions due to traction(8,15,16)
- Lung elastance behavior: In a patient on MV and without diaphragmatic activity, during inspiration, air is directed to non-dependent regions due to collapse of the dependent regions. In the prone position, the availability of the pulmonary parenchyma increases. Collapsed alveoli, potentially recruitable, are reopened, and the inferior lobes (which have a higher quantity of alveoli than the superior lobes) offer higher surface area for diffusion, at once improving ventilatory pressures and decreasing the deformation of fibers (strain) and tension (stress) (Figure 1A and and1B).1B). Prone position varies the pressure gradient distribution in relation to the redistribution of the infiltrated areas, the weight of the cardiac mass (the supine position compresses the left lower lung lobe), variations in EL, and cephalic displacement of the abdomen, which results in more homogenous alveolar ventilation.(8,12,16,19-26)
- Increases in stress and strain produce structural changes in the alveoli, including cellular damage, surfactant dysfunction, edema and increased capillary permeability, and biological alterations, such as increased proinflammatory mediators.(22) Decreases in stress and strain produced by PP can have some influence on these mechanisms and decrease the risk of ventilator-induced damage.(27)
- In patients with severe ARDS, implementation of PP combined with optimization of the positive-end expiratory pressure (PEEP) level post-procedure improves lung volume at the end of expiration, increasing it by approximately 30%, with reductions in elastance and pulmonary resistance. At the same time, PP reduces pulmonary stress (reflected by reduced transpulmonary pressure) and strain (reflected by the relationship between Vt/lung volume at the end of expiration, decreasing from 27% to 33%) compared to Fowler’s position.(28)
- Chest wall elastance behavior: The dorsal region of the chest wall is more rigid than the ventral region due to the presence of the spinal column and para-vertebral muscle masses. When a patient is placed in the PP, thoracic expansion is produced mainly in the direction of the abdominal and dorsal regions
- Prone position and intra-abdominal pressure: Although their behaviors may be unique, we can describe the thoracic and abdominal cavities as two compartments of different volume.(29) The two compartments are occupied by organs of different densities and are separated by the diaphragm. With respect to the difference in chest wall rigidity (the dorsal wall is more rigid than the ventral), both pleural and intra-abdominal pressures would be modified by a change in body position, influenced by the increase in abdominal wall rigidity. Increases in intra-abdominal pressure influence the curvature and position of the diaphragm.(30)
- In the supine position, the abdominal cavity hydrostatic pressure can be as much as five times higher than that in the thoracic cavity,(31) a difference that increases significantly in obese patients.(32) The causes of ARDS are also associated with syndromes that considerably increase the intra-abdominal pressure, such as abdominal compartment syndrome, which can cause pressures up to 34cmH2O.(33) In these conditions, the highest intra-abdominal pressures in supine decubitus correspond to the dorsal regions, where pressure is inexorably transmitted to the pleural space, generating extrinsic compression to the postero-basal pulmonary region. Prone position modifies this situation, and some authors have reported decreased intra-abdominal pressure;(34) in the end, the abdominal wall becomes more rigid, with a resulting increase in intra-abdominal pressure.(35-37)
- Changes in the ventilation/perfusion ratio: Describing a lung model in vertical position suggests a ventilation/perfusion ratio (V/Q) based on a “gravitational” hypothesis, which may explain why perfusion is greater in the more dependent regions of the lungs. Studies of PP, both human and experimental, confirm the hypothesis in which the distribution of perfusion shows a non-gravitational gradient. Upon making the non-dependent zones the more perfused and increasing the ventilated lung volume in PP, a notable improvement in the V/Q ratio is produced. (38-40)
- Effects of the prone position on hemodynamics: We could suppose that the mere fact of changing the mediastinum’s position in the thoracic cavity by placing patients in PP has some hemodynamic effect. In a study of patients without ARDS, the elimination of the weight of the heart from ventral lung zones showed a freeing of a small portion of the lung parenchyma.(46) However, this effect is different in patients with cardiomegaly and congestive heart failure, situations often associated with ARDS, and the improvement in oxygenation upon adopting the PP position is immediate,(47) possibly explained by a greater portion of lung parenchyma freed by this maneuver.(48)
- However, the specific effects on hemodynamic changes have also been studied via impacts on the right-ventricular ejection fraction, (49) favored due to a decrease in the load and explained by PP. Another study (50) demonstrated an increase in preload and a decrease in post load of the right ventricle and an increase in preload of the left ventricle.
- During PP, the pulmonary artery occlusion pressure was also increased, with a decrease in the transpulmonary pressure gradient (difference between the average pulmonary artery pressure and its occlusion pressure), which was associated with “pulmonary vascular dysfunction” and may be associated with an increase in mortality in patients with ARDS.(51,52)
- Prone position also has an impact on the extravascular lung water index, although its clinical relevance has not been observed.(53,54) While large studies on PP in patients with ARDS have excluded those with hemodynamic instability, patients with myocardial ischemia can be more susceptible to cardiac dysfunction during PP. (55-56)