Help Patients Recover From Acute Respiratory Distress Syndrome (ARDS)
Patients admitted to intensive care units who become ventilated are prone to contracting a serious and potentially fatal condition known as acute respiratory distress syndrome (ARDS). ARDS begins when fluid seeps into the lungs and makes it difficult or even impossible for patients to breathe, depriving organs of oxygen. (1) Most patients do not come into the hospital with the syndrome—it tends to develop within two days(2) and can be caused by other conditions ranging from sepsis, to trauma, and even drug toxicity. In the United States alone, there are an estimated 190,600 cases annually. (3)
Here are several strategies respiratory therapists and infection prevention specialists can use to help patients recover from ARDS if it develops:
. In the United States alone, there are an estimated 190,600 cases annually. (3)
Adopt a lung protective ventilation strategy: Mechanical ventilation may be life saving for some patients, but it can also aggravate lung injury, according to a 2015 study in the European Respiratory review.(2) Adopting a strategy of low tidal volume improved survival in patients with ARDS, reduced mortality rate by 22 percent and increased the number of ventilator-free days, according to a study in the New England Journal of Medicine. (3) The same study showed that lower tidal volume also contributed to greater reductions in inflammatory cytokines, which suggested an overall reduction in lung inflammation.
Use neuromuscular blocking agents: Some ventilated patients may find their body’s own breaths competing with the machine, and develop conditions such as dyssynchrony—a mismatching between the patient’s breaths and the ventilator-assisted breaths(5)—or double triggering—when the ventilator’s “inspiratory time” is shorter than the patient’s, which triggers a second ventilator breath(6). To correct these conditions, medications known as neuromuscular blocking agents (NMBAs) can relax the diaphragm and lung activity without causing diaphragm atrophy when used for short periods of time. The European Respiratory review study also found that the administration of NMBAs was associated with fewer pro-inflammatory cytokines. (2)
Maintain spontaneous breathing: Mechanical ventilation can cause diaphragmatic muscle loss and atrophy, which can lead to difficulty weaning or adverse outcomes/prognosis(2). Studies have shown that maintaining some spontaneous breathing contributed to reduced markers of lung inflammation, improved tidal ventilation, and increased systemic blood flow in patients with mild-to-moderate ARDS.(2) However breathing plus ventilation can create additional transpulmonary pressure (2), so therapists must assess the patient’s progress and health to create a tailored program.
Initiate extracorporeal CO2 removal: One of the symptoms of ARDS is respiratory acidosis, (2) a condition where carbon dioxide (CO2) accumulates in the lungs. Thus, respiratory therapists may want to use extracorporeal carbon dioxide removal (ECCO(2)R),(7) to remove CO2 buildup. While this technique is still evolving, in one trial, it was linked to a reduction in the administration of sedatives and analgesics, an increase of spontaneous breathing in patients, and a reduction of pro-inflammatory cytokines. These patients also had shorter ventilation periods as compared with controls. (2).
- Mayo Clinic. ARDS. Symptoms and causes. Available from: https://www.mayoclinic.org/diseases-conditions/ards/symptoms-causes/syc-20355576
- Rittayamai, N. Recent advances in mechanical ventilation in patients with acute respiratory distress syndrome. European Respiratory review. 2015. 24 (135) 132-140; DOI: 10.1183/ 09059180.00012414
- Malhotra, A. Low-tidal-volume ventilation in the acute respiratory distress syndrome. N Engl J Med. 2007, Sep 13; 357(11): 1113-1120. DOI: 10.1056/NEJMct074213
- 4 .No author. Ventilation with lower tidal volumes as compared with traditional tidal volumes for acute lung injury and the acute respiratory distress syndrome. N Engl J Med 2000; 342:1301-1308 DOI: 10.1056/NEJM200005043421801.
- Mellott, K. Patient ventilator dyssynchrony. Crit Care Nurse 2009. Dec(29)6: 41-55. DOI: 10.4037/ccn2009612
- Robinson, B. Patient ventilator asynchrony in a traumatically injured population. Respiratory care. 2013. DOI: 10.4187/respcare.02237. http://rc.rcjournal.com/content/58/11/1847
- Terragni, PP. Extracorporeal CO2 removal. Contrib Nephrol. 2010;165:185-96. doi: 10.1159/000313758. Epub 2010 Apr 20.