Q&A: Acute pulmonary edema etiologies

Q: When is it appropriate to code both flash or acute pulmonary edema and acute on chronic heart failure (diastolic, systolic, or other)? What other etiologies lead to flash pulmonary edema and how do I know when to query?

A: Let’s start by talking about congestive heart failure (CHF) with pulmonary edema versus acute pulmonary edema from other causes. The etiologies for pulmonary edema are divided into two categories: cardiogenic or a non-cardiogenic.

Whenever a patient has an acute episode of CHF, acute pulmonary edema is considered inherent in the exacerbation of CHF. Therefore, acute pulmonary edema that has a cardiogenic etiology is not coded separately.

When documentation supports acute pulmonary edema of non-cardiogenic origin, however, it can be coded separately.

Overview/pathophysiology

Mechanisms for non-cardiogenic pulmonary edema include an increased capillary permeability and changes in pressure gradients within the pulmonary vasculature causing inflammation.

To differentiate non-cardiogenic pulmonary edema from cardiogenic causes, there are a few areas that the CDI specialist can look for in the documentation. Most notably, chest x-rays may reveal bilateral infiltrates with an absence of vascular congestion, absence of jugular venous distention (JVD) as well as the absence of peripheral edema. If a pulmonary capillary wedge pressure is documented, it would be expected to be less than 18 mmHg.

When to query

“Flash” pulmonary edema describes an acute sudden onset but unfortunately, there currently is not an ICD-10 code for the term “flash” and clarification would be needed for the acuity if there is a non-cardiogenic cause documented. Note, however, that this terminology is typically associated with cardiogenic causes.

It’s important for the non-cardiogenic etiology to be clearly documented. If the documentation is unclear, clarification would be needed.

Although linking language is not required, it is best practice to link the etiology to acute pulmonary edema, leaving no question about its underlying cause and providers should be educated as such.

Examples of non-cardiogenic etiologies

Examples of non-cardiogenic etiologies include (but are not limited to):

• Acute respiratory distress syndrome (ARDS)
• Pulmonary embolism
• Sepsis
• Pancreatitis
• Inhalation of toxins
• Overdoses (particularly opiates)
• Trauma
• Transfusion-related acute lung injuries
• Severe infections especially gram-negative pneumonia
• Altitude and pressure changes (known as high altitude pulmonary edema or HAPE)
• Neurogenic pulmonary edema
• Radiation pneumonitis

Patient presentation

The onset of acute pulmonary edema often has a sudden onset, but it can be gradual as well. A patient with acute pulmonary edema typically demonstrates a variety of symptoms such as shortness of breath, especially while lying flat or with activity, wheezing, bilateral infiltrates on chest x-ray (ARDS), a feeling of drowning, tachypnea, tachycardia, dizziness, restlessness, anxiety/agitation, frothy and/or pink tinged sputum, cyanosis and a variety of additional symptoms based on the underlying etiology.

Treatment will be based on the underlying etiology in addition to oxygen supplementation that can include non-invasive or mechanical ventilation depending on the severity and the underlying cause. Prompt identification of the underlying etiology is necessary due to the rapid progression that can occur without treatment.

Editor’s Note: Dawn Valdez, RN, LNC, CDIP, CCDS, CDI education specialist and CDI Boot Camp instructor for HCPro in Middleton, Massachusetts, answered this question. For information, contact her at dvaldez@hcpro.com. For information regarding CDI Boot Camps, click here.