Respiratory acidosis is a serious medical condition in which abnormally slow breathing (hypoventilation) increases the amount of carbon dioxide (CO2) in the blood, causing the pH (acid-base balance) of the blood, and other bodily fluids, to become too acidic.
An important property of any solution, including blood, is its degree of acidity and alkalinity as measured on the pH scale. This essential scale ranges from 0 (very acidic) to 14 (very basic or alkaline). A pH of 7 is considered neutral. The pH of blood is usually slightly basic, ranging from 7.35 to 7.45.
Normally, the kidneys work in tandem with the lungs to keep the bloodâ€™s acid-base balance within normal limits. Breathing thatâ€™s too slow or too shallow leads to increased CO2, levels (hypercapnia) and consequentially, a decrease in pH.
As blood pH drops, the breathing center in the brain tries to compensate by signaling the body to produce faster and deeper breathing in order to increase the amount of carbon dioxide exhaled. The kidneys also work to correct the imbalance by excreting more acid in the urine. If the body continues to produce too much acid, compensatory mechanisms such as these become overwhelmed and severe respiratory acidosis occurs, eventually causing respiratory failure, heart problems and coma.
There are a number of causes of respiratory acidosis; a few are listed below:1
Symptoms of respiratory acidosis vary, depending upon the severity of the underlying disorder and the speed at which CO2 levels rise. Initially, symptoms may be minimal, especially if the hypercapnia is mild and has developed over time. As the acidosis worsens, the following symptoms may occur:1
Treatment of respiratory acidosis begins with focusing on the underlying disorder. If symptoms are severe enough â€“ confusion, lethargy, respiratory muscle fatigue, and a low pH of <7.25 â€“ the patient may have to be admitted to the intensive care unit.1
There are no drugs that specifically treat respiratory acidosis. Rather, medical therapies are directed towards treating the underlying health condition thatâ€™s causing the slow breathing and subsequent acidosis. Medications that may be used in treatment include:1
Oxygen therapy plays a crucial role in the treatment of respiratory acidosis as many patients with high CO2 levels (hypercapnia) also have a decreased amount of oxygen in their blood (hypoxemia). In patients with COPD, long-term oxygen therapy used for more than 15 hours a day has been found to increase survival as well as reduce the risk of high blood pressure in the lungs (pulmonary hypertension).1
Because oxygen therapy has been known to worsen hypercapnia in some patients, caution should be employed when using it.1 To ensure youâ€™re using supplemental oxygen according to your doctorâ€™s prescription, talk to your primary care provider.
Severe respiratory acidosis calls for life-saving measures that includes using either of the following to support breathing:1
For more information about respiratory acidosis, talk to your pulmonologist or primary care provider.
 Byrd, Ryland Jr., MD, et. al. Respiratory Acidosis. Medscape. Last Updated 4/4/2017.
 Lewis, James III, MD. Acid-Base Disorders. Merck Manuals. Last reviewed 5/2016.