Pulmonology Coding Alert

Learn the 3 types of acidosis Knowing the various conditions that cause acidosis and alkalosis, and the differences between the two conditions, can help you understand your pulmonologist's treatment choices and determine which diagnosis codes to link to procedures. Here's an Acidosis Breakdown A patient with respiratory acidosis (276.2) has excess carbon dioxide (CO2) that collects in the blood. The CO2 decreases the blood's pH level. Upper or lower airway obstruction, acute lung infections or inflammation, bronchial tissue infections, and other acute or chronic lung conditions can result in the elevation of carbon dioxide in the arterial blood.

Your pulmonologist may treat the underlying conditions of acute, chronic, and acute on chronic forms of acidosis, says Lewis Taub, MD, a pulmonary specialist at Lovelace Sandia Health System in Albuquerque, N.M.

Here's a breakdown of the three types:

 Acute -- May involve a sudden respiratory system compromise. For instance, the condition could be a result of severe asthma (493.12, Intrinsic asthma; with [acute] exacerbation).
 Chronic -- A gradual and irreversible loss of ventilatory function, such as chronic obstructive pulmonary disease (COPD, 496, Chronic airway obstruction, not elsewhere classified), may lead to this form.
 Chronic on acute -- Similar conditions that lead to the acute form also cause chronic on acute acidosis. The difference is that early signs of discomfort may not be apparent, Taub says. Treat the Underlying Condition When too little carbon dioxide raises the pH level in a patient's blood, the patient may have respiratory alkalosis (276.3). Respiratory conditions, such as pneumonia or acute asthma, can lead to alkalosis.

Generally, alkalosis causes hyperventilation (786.01) and light-headedness (780.4). The physician's treatment options involve treating the underlying condition, Taub says. Use This Real-Life Coding Scenario Although signs and symptoms may lead your pulmonologist to an acidosis or alkalosis diagnosis, you should only link the primary condition to the procedure codes.

Example: A patient with severe asthma (493.12) develops fever (780.6), wheezing (786.07) and fatigue (780.79). Testing confirms that the patient has acidosis (276.2). The physician inserts an endotracheal tube (31500, Intubation, endotracheal, emergency procedure) during treatment.

How to do it: When you report 31500, make sure you link the underlying condition, 493.12 (asthma) to the procedure code, not 276.2, which is the secondary condition. You should use 493.12 because acidosis is the physician's official diagnosis, whereas wheezing and fatigue are signs and symptoms.