PRONE POSITIONRESCUE THEAPY FOR SEVERE ARDS

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Acute Respiratory Distress Syndrome (ARDS) is defined as a:

“syndrome of acute and persistent lung inflammation with increased vascular permeability” (Hansen-Fletcher et al)

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Clinically, ARDS is characterized by:

• acute onset (< 48 hours)

• bilateral infiltrates• PaO2/FiO2 ratio

<300mmHg• No evidence of

cardiac causes

PRONE POSITION• ARDS is classified by its cause:

– Direct lung injury: pneumonia, aspiration, inhalation injuries, ect..

– Indirect lung injury: sepsis, OD, massive blood transfusions, ect..

• Its severity (PaO2/Fio2 ratio):

– mild (200-300 mmHg)

– moderate (100-200 mmHg)

– severe (<100mmHg)

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Recovery Stage

• Slow restoration of lung function

Proliferative Stage

• 7—21 days• Alteration of lung tissue• Poor Compliance• Decreased Edema

Exudative Stage

• 0-7 days• Edema (peaks 048hrs)• Inflammation

Typically, lung dysfunction is the worst during the first 0-48hours and may last for up to a week.

PRONE POSITIONTreatment of ARDS:

• Treat underlying cause (i.e. sepsis)• Lung protective ventilation (low Vt +

adequate PEEP)• Avoid a positive fluid balance

However, in severe cases of ARDS (low pH, O2 and high CO2 and airway pressure) standard therapy main fail.

Rescue therapy may be needed: prone position

Prone Position

ECMO

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Indications for the prone position:

Capital Health Prone Criteria:

• ARDS

• < 48 hours

• Pa02/FiO2 <200mmHg

PRONE POSITIONRelative contraindications for the prone position:

• Elevated ICP• Intestinal ischemia• Obesity• Recent Abdominal Surgery

Absolute contraindications for the prone position:

• spinal cord instability,• unstable facial fractures• anterior burns, open abdomen• increased abdominal pressures• unstable pelvic fractures.

PRONE POSITIONThe Prone Position:

• Improves perfusion to the lungs → Better V:Q matching

• The diaphragm drops and the heart shift forward → Improved compliance

• Improved lung recruitment

• Lung Protective

• Indicated:• Moderate to Severe ARDS• Early (<48hours)• Duration: 12 – 16 hours

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• In healthy lungs the distribution of perfusion is effected by gravity.

• The apex and the middle of the gets more ventilation (V) than perfusion(Q). V>Q

• At the base, the lungs get more perfusion (Q) than ventilation (V). V<Q

• Atelectasis and inflammation of the lungs leads to worsening V:Q matching

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Perfusion (Q) of the anterior and base of the lungs improves in the prone position.

• The improved V:Q matching may improve oxygenation.

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The diaphragm drops and the heart shift forward → Improved compliance

May lower airway pressure

May improve VT and MV (↓CO2)

May reduce lung protective (↓ atelectotrauma, barotrauma & volutrauma)

PRONE POSITIONNURSING CARE:• Ensure adequate sedation and analgesia (meet goal

RASS)• Ensure adequate paralysis (meet TOF goal)• ABG PRN to assess oxygenation (PaO2) &

ventilation (PaCo2)• Reposition arms Q2H (see prone policy)• Check Q2H for pressure areas• Family education

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IN CONCLUSION:• Current research (PROSEVA) demonstrates

that the prone position is may be beneficial in severe ARDS (<48 hours).

• Duration 16-24 hours• Inexpensive compared and easy to perform• May be lung protective (improve compliance) • May improve oxygen and ventilation (better

V:Q matching)

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THANK YOU!