Documentation tips: Acute respiratory failure

It’s always important for everyone to remember why we document things in the chart so that we are on the same page and ultimately do what is best for the patient. We document for insurance companies to prove the need for hospitalization, for legal purposes, and for other clinicians – to clearly communicate the acuity of each patient.

Dr. Sarah O. DeCaro

One of the diagnoses that we can often forget to use is acute respiratory failure. Documenting acute respiratory failure matters, regardless if it is, or is not, the primary diagnosis; it increases the estimated Length of Stay (LOS), Severity of Illness (SOI), and Risk of Mortality (ROM). This diagnosis adds an additional degree of specificity to patients with pneumonia, pleural effusions, chronic obstructive pulmonary disease (COPD) exacerbations, etc. While we may be hesitant to document this (perhaps feeling that this applies only to patients who are intubated in the ICU), the reader will hopefully have more confidence using it after reviewing the diagnostic criteria.

Acute respiratory failure can stem from impaired oxygenation or impaired ventilation. The following are some examples that follow these principles:

• Impaired oxygenation. Can be seen in pneumonia, pulmonary edema, and pulmonary embolism, and can present as a low O₂ saturation or a low pO₂ on an arterial blood gas (ABG) test.
• Impaired ventilation. Can be seen in COPD or asthma where there is increased effort to ventilate the lungs, which can lead to impaired CO₂ exchange and subsequent acidosis.

One needs to have two of the following three criteria to make a formal diagnosis of acute respiratory failure:

• pO₂ less than 60 mm Hg (hypoxemia).
• pCO₂ greater than 50 mm Hg (hypercapnia) with pH less than 7.35.
• Signs and symptoms of acute respiratory distress.

One may think that it would be difficult to meet criteria without an ABG. Although an ABG is the standard, a patient meets criteria 1 without a blood gas if an oxygen saturation less than or equal to 90% is documented. Therefore, in most cases, if you have a documented oxygen saturation less than or equal to 90% on room air with a physical exam showing signs of respiratory distress, your patient will qualify for the diagnosis of acute respiratory failure. This negates the need to always have an ABG.

It is important to document the symptoms and physical exam findings that go along with the diagnosis. Patients should have tachypnea with a respiratory rate (RR) greater than 20 or a decreased rate less than 10. They may have wheezing, difficulty moving air, nasal flaring, and accessory muscle use. All of these findings are extremely helpful to validate the diagnosis and would make it extremely difficult for it to be rejected by a biller or insurance company.

These patients are often given supplemental oxygen (nasal cannula, Venturi mask, non-rebreather) and other treatments including steroids, inhaled bronchodilators, mucolytics, and respiratory therapy. Documenting these interventions in your plans can assist reviewers trying to understand your thought process in the treatment of the patient. If your patient has to be initiated on bilevel positive airway pressure (i.e. – the patient was not on BIPAP at home, but needed to be started because of his/her respiratory status), this almost always means they have acute respiratory failure.

In the two tables accompanying this article, we see some examples of how documenting acute respiratory failure can improve LOS, ROM, SOI, and reimbursement. The number at the top is based off of a specific DRG (Diagnosis Related Group) that is used by coders.

Let’s say we have a 58-year-old male presenting with chest pain, shortness of breath, and concern for unstable angina. Given his symptoms, he is being taken to the cardiac catheterization lab. If we note only that he was hypoxic and required 3L for an O₂ saturation of 94%, one can see the ROM, SOI, estimated LOS, and reimbursement in the first column. However, if we write that his oxygen saturation on room air is 87%, he is using intercostal muscles to breathe, and he has marked dyspnea with conversation, we can say that he has acute respiratory failure. Making this distinction increases his expected LOS by almost 4 days and nearly doubles reimbursement.

For the second example, we have an 81-year-old female with diabetes type 2, hypertension, and chronic systolic congestive heart failure who presents with an acute systolic CHF exacerbation. The patient is saturating 85% on room air, has tachypnea (RR 34), and was given large doses of intravenous furosemide in the emergency department. She is stabilized with improvement in her respiratory rate and can go to the floor, but by documenting that this was acute respiratory failure, one can again see the significant improvements in the projected LOS, ROM, and reimbursement as opposed to documenting hypoxia. This has huge implications for our hospitals, and we should continue to strive to document this as clearly as possible.

Key take-home points for hospitalists

• Document accurately, including any comorbid conditions and major comorbid conditions that are applicable.
• Acute respiratory failure comes from impaired oxygenation, impaired ventilation, or both.
• One needs to document two of the three criteria to formally diagnose acute respiratory failure: pO₂ less than 60 mm Hg (or room air oxygen saturation less than or equal to 90%), pCO₂ greater than 50 mm Hg with pH less than 7.35, and signs/symptoms of respiratory distress.
• Document physical exam findings that correlate with acute respiratory failure (RR greater than 20 or less than 10, wheezing, nasal flaring, accessory muscle use, etc).
• If your patient has to be initiated on BIPAP (i.e. – the patient was not on BIPAP at home, but needed to be started because of his/her respiratory status), they likely have acute respiratory failure.

Dr. DeCaro is a hospitalist and medical director for care coordination at Emory University in Atlanta.