Q&A: ARDS FAQs

Editor’s note: Richard Pinson, MD, FACP, CCS, answered these questions after the May 8, 2019, episode of the ACDIS Podcast: Talking CDI. Pinson is the co-author of the CDI Pocket Guide and the Outpatient CDI Pocket Guide: Focusing on HCCs. He and Cynthia Tang, RHIA, CCS, are principals at Pinson and Tang, LLC. Contact him at rpinson@pinsonandtang.com.

Q: Can you clarify the PaO2/FIO2 (P/F) ratio criteria in the proper setting for acute respiratory distress syndrome (ARDS)?

A: While further investigating your question, I found a 2018 update to the 2012 Berlin ARDS definition in a 2018 edition of the Journal of the American Medical Association (JAMA).

First, the treatment of ARDS requires some form of positive pressure ventilatory support to open alveoli and force fluid out of them: either non-invasive with continuous positive airway pressure (CPAP) or invasive with positive end-expiratory pressure (PEEP).

The updated P/F threshold ratios for ARDS are now P/F ratio less than or equal to 300 for:

• Non-invasive ventilation with CPAP greater than or equal to 5, or
• Invasive ventilation with PEEP greater than or equal to 5

The 2012 P/F criterion of less than or equal to 200 without CPAP or PEEP discussed on the ACDIS Podcast was eliminated in the 2018 update.

Keep in mind that P/F ratios alone do not establish a diagnosis of ARDS for which both an inciting event and characteristic imaging are necessary.

Q: Why is ARDS coded as a lesser weighted diagnosis than acute respiratory failure when it is clearly a more severe situation?

A: Until the fiscal year (FY) 2019 inpatient prospective payment system (IPPS) final rule, ARDS (code J80) was classified as a CC whereas acute respiratory failure codes were MCCs. In FY 2019 (current), code J80 was upgraded to an MCC and remains so.

Code J80 and the acute respiratory failure codes in category J96 are not listed as downgrades to CC status in the 2020 proposed rule. However, codes J95.1, Acute pulmonary insufficiency following thoracic surgery, and J95.821, Acute post-procedural respiratory failure, are listed.

Q: If acute respiratory failure is present on admission (POA) and then a patient later develops ARDS, which gets coded? Do you lose the acute respiratory failure as POA?

A: The Official Guidelines for Coding and Reporting, Section I.A.12a. (Excludes 1), was modified in FY 2017 to include the following:

An exception to the Excludes 1 definition is the circumstance when the two conditions are unrelated to each other. If it is not clear whether the two conditions involving an Excludes 1 note are related or not, query the provider.

If acute respiratory failure were present on admission and an event causing ARDS (clearly unrelated to the initial respiratory failure) occurred subsequently, both would be coded with POA indicator Y for acute respiratory failure and POA indicator N for ARDS to fully describe the unique circumstances in this situation.

Since these conditions are so intimately related clinically and for coding purposes, I would recommend a query about their relationship if not already documented in the record.

Q: When my facility has had denials for acute respiratory failure and our rebuttal includes the P/F ratio, the reply has rejected the P/F ratio as substantiating evidence that clinically validates the diagnosis unless it has been specifically documented by the physician or mid-level provider in the clinical note. Can you offer any advice to overcome this objection?

A: I recommend a response that clinical validation depends only on medical record findings that support and substantiate the diagnosis. It is not required that a provider specifically state what the basis of a diagnosis is if it can be confirmed/validated by medical record findings.

For example, a provider does not have to specifically state what the findings are that substantiate the diagnosis of sepsis, pneumonia, acute kidney injury, or any other diagnosis.

Q: How does the treatment of ARDS differ from cardiogenic pulmonary edema?

A: The treatment of ARDS is primarily supportive with supplemental oxygen, respiratory support and positive airway pressure (CPAP or PEEP).

Cardiogenic pulmonary edema is treated with supplemental oxygen and treatment of the underlying heart failure with IV diuretics and other modalities if needed. Respiratory support is not usually necessary.