What is Prone Positioning?

Prone positioning, or “proning” is a new form of treatment sometimes used to support mechanically ventilated patients with ARDS who require high concentrations of inspired oxygen. To initiate prone positioning medical staff turn an ARDS patient face down from his or her back (supine position). Thereafter, the patient may be turned from one position to the other as often as three times a day until the requirement for a high concentration of inspired oxygen resolves.

How Does Prone Positioning Help?

One important goal for the supportive treatment of patients with ARDS is to maintain adequate oxygenation of the blood by the injured lungs PO2 greater than 60 while avoiding a potentially toxic concentration of inspired oxygen (greater than 60-70% oxygen). Prone positioning often improves oxygenation in patients who have ARDS by shifting blood flow to regions of the lung that are less severely injured and thus better aerated.  With the proper equipment, proning may also allow the abdomen to expand more and facilitates better movement of the diaphragm. 

Is Proning an Effective Technique?

Researchers have not reached a consensus as to whether prone positioning improves the survival rate among ARDS patients.  However, most research has shown that proning does improve oxygenation, significantly in some cases.  Unfortunately, not all ARDS patients respond favorably to prone positioning, and the benefit sometimes wanes over time.

Should Every ARDS Patient Be Proned?

Not all patients are in a physical condition that permits such movement of the body.  Patients whose heads cannot be supported in a face-down position, those who have circulation problems, or very large patients are not recommended for the proning technique.  Some injuries, such as a broken pelvis for example, and other conditions as determined by the attending physician may also disqualify a patient from being proned.

Even advocates of the technique do not typically recommend proning as a “routine” intervention for ARDS patients. Because there is a small risk of complications associated with turning critically ill patients, most researchers and advocates recommend the technique be reserved for those patients with severe hypoxemia, or low blood oxygen levels.

How is Proning Performed?

Proning is performed by a specific procedure that generally involves several critical care staff and is usually overseen by the attending physician.   Specific training for critical care staff is available.

How Long Should a Patient Be Proned?

Though available research makes no specific recommendations, 6 or more hours a day, for as long as 10 days, appears typical in clinical studies and reported practice.

What are the Risks of Proning?

Even with proper equipment, physically flipping over a critically ill patient has risks, particularly since the patient will be hooked up to many wires and tubes.  Possible problems include unintended extubation (tubes coming out), airway obstruction, and difficulties coordinating the ventilator. Some patients may require increased sedation and muscle relaxants, may experience facial swelling, and may develop “pressure sores” on the weight-bearing parts of the body, such as the knees and chest.

Though there are risks, critical care staffs that attempt to prone an ARDS patient are trained to follow established procedures to ensure safety.  The physical difficulties of proning have been the traditional barrier to its use.  Progress through equipment innovations such as the Vollman Prone Positioner (www.vollman.com), a lightweight, cushioned frame that straps to the front of the patient before turning, has helped to minimize the risks associated with moving patients and maintaining them in the prone position for several hours at a time.

References

Prone Positioning of Patients With Acute Respiratory Distress Syndrome: A Systematic Review,

American Journal of Critical Care, November 1999, Vol 8, No. 6

Effect of Prone Positioning on the Survival of Patients with Acute Respiratory Failure, New England Journal of Medicine, August 23, 2001, Vol 345:568-573 No. 8

The Acute Respiratory Distress Syndrome, Mechanical Ventilation, and the Prone Position, New England Journal of Medicine, August 23, 2001, Vol 345:568-573 No. 8

Vollman Prone Positioner, Policy and Procedure, http://www.vollman.com

Computer-Supported Continuous Axial Rotation Therapy In Prone Position For Complex Polytrauma Patients With ARDS, Klinikum der Philipps-Universität Marburg, www.med.uni-marburg.de/unfchir/projekte/p_intmed_1.html

Teamwork, Technology Save Life of Expectant Father, Community Spirit, Community Hospitals Foundation of Indiana.