CCONSIDER THE FOLLOWING scenario: a patient is admitted through the emergency department (ED) with acute shortness of breath. The ED notes and history and physical document acute respiratory failure. Blood gases show an oxygen level of 75, pCO2 level of 40, and a blood pH of 7. 40. The chest X-ray shows infiltrates and the patient is treated with antibiotics and respiratory therapy. The discharge summary gives a final di- agnosis of pneumonia without mention of respiratory failure. Should acute respiratory failure be coded? This coding scenario is seen frequently in the acute care setting. Respiratory failure in this situation, and when it is present with other conditions, has long caused confusion for coding profes- sionals. ICD-10-CM brought about more specificity to identify
variations in the condition, but coding guidance has remained
consistent with ICD-9-CM guidelines. Let’s explore the clinical
indicators for respiratory failure, examine the current coding
guidelines, and look at this and other related coding scenarios.
Respiratory Failure Definition
Respiratory failure is a life-threatening condition that results
from inadequate gas exchange by the respiratory system. It presents with abnormal arterial oxygen and/or carbon dioxide levels
and is usually due to an underlying cause. Symptoms of acute
respiratory failure include extreme shortness of breath; rapid
respiratory rate using accessory muscles of respiration such as
intercostal muscle retraction, paradoxical breathing, or cyanosis; loss of consciousness; increased heart rate; and a decrease of
oxygenated blood with blood gas measurements of pO2 less than
60, pCO2 greater than 50, and arterial blood pH less than 7. 35. A
pO2 decrease of 15 mm Hg from the patient’s normal pO2 or an
arterial blood pH less than 7. 35 in a patient with chronic lung dis-
ease may be an indicator of respiratory failure. Increased respira-
tory rate, abnormal blood gases, and evidence of increased work
of breathing are usually included in the definition of respiratory
failure in clinical trials. Hypoxemia is when blood oxygen drops,
showing a pO2 of less than 8kPa, and hypercapnia is when blood
carbon dioxide levels rise, showing a pCO2 of greater than 6.0kPa.
There are two classifications of respiratory failure, Type I and
Type II. Type I respiratory failure shows low oxygen and normal
or low carbon dioxide levels. Type II shows hypoxemia with hy-
percapnia. It is caused by inadequate alveolar ventilation and
both oxygen and carbon dioxide are affected. The buildup of car-
bon dioxide levels generated by the body cannot be eliminated.
Acute respiratory failure requires close patient monitoring
and evaluation with aggressive respiratory therapy and/or mechanical ventilation. The absence of mechanical ventilation
does not preclude the diagnosis of respiratory failure.
Coding Respiratory Failure as Principal Diagnosis
In order to report respiratory failure as the principal diagnosis
code, the failure must be present on admission and be the main
reason for treatment after study, except in a few limited situations. These situations include:
1. Poisoning causing respiratory failure. When the patient
is admitted with respiratory failure due to an intentional
drug overdose, or due to drug abuse/dependence, the poisoning code is listed as the principal diagnosis code.
2. An obstetrics condition causing respiratory failure.
Coding Respiratory Failure
By Monica Leisch, RHIA, CDIP, CCS