Should Oxygen Therapy Alone Be Used in Sleep Apnea Treatment?

Nocturnal Oxygen Use May Not Resolve Breathing Obstruction, Sleepiness

Oxygen therapy alone is not enough to treat sleep apnea and may be used with CPAP therapy if underlying lung disease is present
Oxygen therapy alone is not enough to treat sleep apnea and may be used with CPAP therapy if underlying lung disease is present. Astronaut Images / Getty Images

Oxygen therapy is sometimes used to treat sleep apnea, especially when concern for the disorder is first raised. However, in some settings, oxygen use may actually do more harm than good. Should oxygen therapy alone be used to treat obstructive sleep apnea? When might a pulmonary condition require its supplemental use? Learn about the role of oxygen in sleep apnea and whether you need it to treat you disorder.

The Use of Oxygen in Sleep Apnea

Sleep specialists often encounter patients who are referred for a sleep study to diagnose and treat suspected sleep apnea. The referring physicians, out of an interest to protect their patients, may prescribe supplemental oxygen to be used overnight while awaiting referral and testing. This is delivered through plastic tubing called a nasal cannula, typically at a rate of several liters per minute. Is this therapy appropriate or even helpful?

The theory seems sound: The oxygen levels of the blood drop overnight (i.e., hypoxemia) due to repeated pauses in the breathing called apnea, so we will give supplemental oxygen to get things back into the normal range. Unfortunately, though the oxygen numbers may normalize, other changes caused by the apnea (such as carbon dioxide retention and awakenings leading to fragmented sleep) may not.

Sleep apnea often is due to the collapse of the tissues of the upper airway.

If the throat is partially or completely closed, it doesn't matter how much oxygen is delivered via a nasal cannula, this oxygen will not reach the lungs. Unfortunately, the oxygen cannot get to where it needs to go, and it will not help enough. There are other conditions in which the therapy is likely to fail, and may even become harmful.

Why Oxygen Does Not Work

Using supplemental oxygen in people with sleep apnea and normal respiratory function has mixed results. The measured oxygen level will indeed improve. However, the effect on the apnea-hypopnea index (AHI) and the length of apneic events is negligible. Excessive daytime sleepiness, a significant complaint in sleep apnea, does not improve. This is due to the persistence of sleep fragmentation that is not alleviated by oxygen use. The use of oxygen may give a false sense of protection while the condition and its associates symptoms remain inadequately treated.

Moreover, the levels of carbon dioxide during the night and daytime may increase when oxygen is used overnight. Oxygen use alone does not improve the levels of excessive carbon dioxide that may accumulate during sleep, and this can be dangerous.

The Danger of Oxygen Use with Sleep Apnea and COPD

There are situations where the use of oxygen to treat sleep apnea may actually be dangerous. When chronic obstructive pulmonary disease (COPD), such as emphysema, occurs alone, oxygen has been shown to be beneficial.

However, when it occurs with obstructive sleep apnea, a different picture emerges.

In this so-called "overlap syndrome," the use of nocturnal oxygen without relief of the airway obstruction can cause worsened breathing overnight. This may result in complaints such as morning headache or confusion. Therefore, it is important that continuous positive airway pressure (CPAP) or bilevel therapy be used to treat the obstruction, with supplemental oxygen infused into the system as needed to confer the other benefits.

Therefore, it is important that individuals with COPD undergo a sleep study if there is suspicion of sleep apnea contributing to their complaints. And, clearly, oxygen alone is not an adequate treatment for those suspected of having sleep apnea.

Oxygen therapy may be added to CPAP or bilevel therapy if the oxygen levels remain low overnight, despite adequate treatment of the associated sleep apnea. This suggests that the lungs are unable to sufficiently extract enough oxygen, even when the upper airway is maintained open.

If you are concerned about your breathing during sleep, speak with a board-certified sleep specialist and get the treatment that you need.

Sources:

Gold, A et al. "The effect of chronic nocturnal oxygen administration upon sleep apnea." Am Rev Respir Dis 1986;134:925.

Masa, JF et al. "Noninvasive positive pressure ventilation and not oxygen may prevent overt ventilatory failure in patients with chest wall diseases." Chest 1997;112:207.

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