Pulmonology Coding Alert

There are two key points to proper reimbursement when coding treatment for respiratory acidosis (276.2) and respiratory alkalosis (276.3): assigning the proper diagnosis codes and reporting all services provided.

Coders often confuse acidosis and alkalosis, which can impact reimbursement significantly. Reporting the wrong ICD-9 code can mean not showing medical necessity, causing carriers to refuse payment. And in the case of acidosis and alkalosis and the extensive treatments that may be required, a sizable reimbursement could be reduced significantly.

Respiratory acidosis occurs when excess carbon dioxide collects in the blood, decreasing its pH level. The excess carbon dioxide can be caused by upper or lower airway obstruction, acute infections or inflammation of the lung and bronchial tissues, or acute or chronic lung conditions, all of which prohibit the lungs from expelling carbon dioxide from the body. Hypercapnia (increased carbon dioxide in arterial blood) can also occur in association with sleep disorders.

There are two types of respiratory acidosis: acute and chronic. Acute acidosis involves a relatively sudden malfunction of the respiratory system. Chronic acidosis is caused by a gradual and irreversible loss of ventilatory function, as with chronic obstructive pulmonary disease (COPD, 496).

Respiratory alkalosis results when too little carbon dioxide in the blood raises its pH level. Although rare, alkalosis may be associated with anxiety, hysteria, pain, hypoxia, fever, high environmental temperatures, early pulmonary edema, and overven-tilation with a mechanical ventilator.

The principal diagnostic test for respiratory acidosis and alkalosis is an arterial blood gas (ABG) study (82800-82810). A blood sample is taken from the artery to evaluate the ability of the lungs to move oxygen in and carbon dioxide out of the body. The sample is taken from the artery so the oxygen and carbon dioxide levels can be measured before they change when the blood enters body tissues. Often, the physician requires several ABGs to monitor the progress of the patient's condition.

Pulmonologists most often encounter potential acidosis/alkalosis patients in the emergency department (ED) or in inpatient units. The facility bills for an arterial puncture (36600*, Arterial puncture, withdrawal of blood for diagnosis) and ABG (82800-82810) if its equipment, supplies and staff are used to perform the procedures and analyze the specimen. Nonetheless, the pulmonologist may incorporate the amount and complexity of data reviewed, including the ABG test results, in medical decision-making when determining the E/M service code (99281-99285, Emergency department visit for the evaluation and management of a patient ; or 99221-99223, Initial hospital care, per day, for the evaluation and management of a patient ).

There are four potential keys to treating respiratory acidosis: maintaining a clear airway, ensuring the patient is receiving sufficient oxygen, administering antibiotics if infection is suspected, and applying bronchodilators. In the ED or inpatient setting, maintaining clear airways and adequate oxygenation may require placing the patient on a ventilator.

In this situation, the pulmonologist would insert an endotracheal tube (31500, Intubation, endotracheal, emergency procedure) and provide ventilator management (94656, Ventilation assist and management, initiation of pressure or volume preset ventilators for assisted or controlled breathing; first day). For each subsequent day the pulmonologist provides ventilator management, you should report 94657 ( subsequent days). "The ventilator makes sure the patient is receiving the oxygen he or she needs and removes carbon dioxide in the exhaled gas. Direct suctioning of the upper airways will help to keep the airway clear," says Walter J. O'Donohue, MD, FCCP, founding chairman of the CPT committee of the American College of Chest Physicians (ACCP) and a representative to the AMA CPT advisory committee for ACCP.

For example, a hospital patient develops acute pulmonary edema (518.4) and goes into respiratory failure. The pulmonologist who is called in orders an ABG, which reveals pulmonary acidosis. The pulmonologist then places the patient on a ventilator, monitoring his condition for about 20 minutes until he stabilizes.

"A consult (99251-99255) seems the most appropriate service to report, as long as the pulmonologist's documentation fulfills the requirements," says Mary Mulholland, RN, BSN, CPC, a reimbursement analyst for the office of clinical documentation at the University of Pennsylvania's department of medicine in Philadelphia. "The request for the pulmonologist's opinion should be documented in the medical record, and the pulmonary physician provides and documents all of the key components for a consultation history, exam and medical decision-making." The pulmonologist must provide a report of his or her findings to the physician who requested the consult, Mulholland stresses.

If the pulmonary physician intubated the patient, he or she could report 31500. You can report ventilation management (94656) in addition to the intubation if the pulmonologist did not perform the inpatient consultation. Otherwise, because 94656 is bundled into 99251-99255 by the Correct Coding Initiative, you should bill the intubation and the consult appended with modifier -25 (significant, separately identifiable evaluation and management service by the same physician on the same day of the procedure or other service).

If the patient is critically ill or injured and suffering from acidosis, the pulmonologist may be able to report his or her services with the critical care codes. (See article 2 "Critical Care Can Raise Payment for Acidosis Treatment".)

Respiratory alkalosis treatment may be as simple as having the patient breathe into a paper sack or asking the patient to hold his or her breath. If the alkalosis results from overventilation by a ventilator, controlling the condition would be a part of ventilator management. Time spent determining the proper treatment would be counted toward the medical decision-making component of the E/M service reported for that day.

On occasion, a patient with a central nervous system disease who is unable to control his or her breathing may have respiratory alkalosis. In this case, the patient may not be able to hold his or her breath or breathe into a paper sack. And mechanical ventilation may be overkill. Instead, the pulmonologist may sedate the patient (99141-99142) to allow his or her body to regulate the amount of carbon dioxide in the blood. According to the 2002 Physician Fee Schedule, conscious sedation is a bundled service. Payment for these services "is always bundled into payment for other services not specified," according to CMS.