The effectiveness of oxygen for adult patients with pneumonia

Pneumonia is an inflammatory condition of the lungs. Treatment for pneumonia includes antibiotics, rest, fluids, management of complications and professional home care. Oxygen supplementation is one way to help patients who cannot breathe adequately on their own. Management of oxygen supplementation is divided into nasal cannula and mechanical ventilation. Mechanical ventilation is life-supporting ventilation that involves the use of a machine called a ventilator, or respirator. There are two main types of mechanical ventilation: non-invasive ventilation (NIV) and invasive ventilation. The former provides ventilatory support to a patient through a tightly fitted facial or nasal mask and the latter through a tube inserted into the windpipe through the mouth or the nose or a hole made in the windpipe through the front of the throat. At present, oxygen therapy for individuals with pneumonia is commonly prescribed. However, inconsistent results on the effects of oxygen therapy on pneumonia have been reported and no systematic review has been conducted in patients with pneumonia to determine which delivery system of oxygen therapy leads to the best clinical outcomes.

We searched the related literature and included three randomised controlled trials involving 151 adults with pneumonia aged around 60 years. We did not include patients with pulmonary tuberculosis or cystic fibrosis. We found that NIV can reduce the risk of death in the intensive care unit (ICU) and the need for endotracheal intubation, shorten ICU stay and length of intubation. Some outcomes and complications of oxygen therapy depended upon the delivery system and primary diseases. The most common complications of invasive ventilation are ventilator-associated pneumonia. However, we must be aware that oxygen therapy is just one of the treatments for pneumonia and the other standard treatments used by physicians are of equal importance.

The evidence is weak and it is limited by the small number of studies and the small number of study participants.

Authors' conclusions: 

Non-invasive ventilation can reduce the risk of death in the ICU, endotracheal intubation, shorten ICU stay and length of intubation. Some outcomes and complications of non-invasive ventilation were varied according to different participant populations. Other than the oxygen therapy, we must mention the importance of standard treatment by physicians. The evidence is weak and we did not include participants with pulmonary tuberculosis and cystic fibrosis. More RCTs are required to answer these clinical questions. However, the review indicates that non-invasive ventilation may be more beneficial than standard oxygen supplementation via a Venturi mask for pneumonia.

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Background: 

Oxygen therapy is widely used in the treatment of lung diseases. However, the effectiveness of oxygen therapy as a treatment for pneumonia is not well known.

Objectives: 

To determine the effectiveness and safety of oxygen therapy in the treatment of pneumonia in adults older than 18 years.

Search strategy: 

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) 2011, Issue 4, part of The Cochrane Library, www.thecochranelibrary.com (accessed 9 December 2011), which includes the Cochrane Acute Respiratory Infections Group's Specialised Register, MEDLINE (1948 to November week 3, 2011) and EMBASE (1974 to December 2011).

Selection criteria: 

Randomised controlled trials (RCTs) of oxygen therapy for adults with community-acquired pneumonia (CAP) and nosocomial (hospital-acquired) pneumonia (HAP or NP) in intensive care units (ICU).

Data collection and analysis: 

Two review authors independently reviewed abstracts and assessed data for methodological quality.

Main results: 

Three RCTs met our inclusion criteria. The studies enrolled 151 participants with CAP or immunosuppressed patients with pulmonary infiltrates. Overall, we found that non-invasive ventilation can reduce the risk of death in the ICU, odd ratio (OR) 0.28, 95% confidence interval (CI) 0.09 to 0.88; endotracheal intubation, OR 0.26, 95% CI 0.11 to 0.61; complications, OR 0.23, 95% CI 0.08 to 0.70; and shorten ICU length of stay, mean duration (MD) -3.28, 95% CI -5.41 to -1.61.

Non-invasive ventilation and standard oxygen supplementation via a Venturi mask were similar when measuring mortality in hospital, OR 0.54, 95% CI 0.11 to 2.68; two-month survival, OR 1.67, 95% CI 0.53 to 5.28; duration of hospital stay, MD -1.00, 95% CI -2.05 to 0.05; and duration of mechanical ventilation, standard MD -0.26, 95% CI -0.66 to 0.14. Some outcomes and complications of non-invasive ventilation were varied according to different participant populations. We also found that some subgroups had a high level of heterogeneity when conducting pooled analyses.