Although the transition to ICD-10 from ICD-9 has been delayed until Oct. 1, 2015, hospitalists should become familiar with the new code set in advance. In particular, since ICD-10 allows greater specificity for assigning codes, hospitalists should learn when and how to provide more detailed documentation. This will help to accurately reflect severity of illnesses, complexity and quality of care, and overall use of resources. Below are a few common conditions for which detailed documentation may be especially helpful.
Glasgow Coma Scale
Coma represents a profound alteration of mental status ranging from obtundation with impaired responsiveness to unconsciousness with some responsiveness to complete unresponsiveness. There are many different causes, such as head trauma, brain edema or compression, severe metabolic/physiologic disturbance, drugs, and toxins.
In both ICD-9 and ICD-10, explicit use of the diagnostic term “coma” allows for its coding assignment. However, ICD-10 allows for the incorporation of the Glasgow Coma Scale (GCS) score into coding, either as a whole score or through use of its individual components (eye-opening, verbal and motor response categories). Documenting and coding the score will help to specify a patient's condition, as well as how it may change over time (if the score is calculated repeatedly). The GCS also can be used in patients who aren't “comatose,” as the score ranges from 3-15 and measures all levels of responsiveness from normal to total absence, as well as classifies the degree of impairment as severe (3-8), moderate (9-12), and minor (13 or more) (see Table 1).
The ICD-9 classification has only one code to describe hepatic encephalopathy. Most patients with hepatic encephalopathy are treated on a continuous basis with oral lactulose to lower blood ammonia levels, preserve mental status, and prevent coma. Much confusion and disagreement have clouded the coding of hepatic encephalopathy in patients with normal mental status who are taking lactulose. ICD-10 resolves the controversy by creating two codes: one for those “without coma” and another for those with significant symptoms (described as “with coma” in ICD-10). ICD-10 leaves the determination of what symptoms of hepatic encephalopathy constitute “with coma” to the physician.
Acute respiratory failure
The distinction between hypoxemic and hypercapnic respiratory failure (see Table 2) has important clinical implications. Unlike ICD-9, ICD-10 now allows for their separate coding. While unspecified acute respiratory failure will remain acceptable for severity classification, distinguishing between the two will permit more accurate data analysis to understand clinical differences, complications, and outcomes.
Also, even though the diagnosis of “respiratory acidosis” is the clinical equivalent of “acute hypercapnic respiratory failure,” it is not classified as such for coding purposes and does not represent the same severity. For this reason, “acute hypercapnic respiratory failure” is the preferred diagnostic terminology for ICD-10.
The difference between fractures primarily related to osteoporosis and those due to significant trauma is an important but frequently difficult diagnostic distinction. Osteoporotic fractures are classified clinically and for coding purposes as pathologic fractures, but many physicians reserve the term “pathologic” for those fractures related to a malignant lesion in the bone.
The actual definition of pathologic fracture (including those due to osteoporosis) is one that occurs in underlying abnormal bone (of any cause) when the degree of trauma would not be expected to cause a fracture in normal healthy bone. Such is almost always the case in elderly patients who simply fall down and sustain a fracture.
In most cases, Medicare does not consider inpatient admission necessary for traumatic fractures (including vertebral compression fractures). However, a “pathologic” fracture (including osteoporotic) is considered significant and serious.
While ICD-9 has required specific diagnostic documentation linking underlying osteoporosis to any fracture to avoid inappropriately coding a traumatic fracture, ICD-10 does not. Any fracture occurring in a patient with osteoporosis is assumed to be osteoporotic and will be coded as “pathologic” if the trauma sustained would not be expected to fracture a normal bone. Coders are expected to make this determination if it is evident, but if it's not, clinicians will need to clarify. Ideally, physicians should understand these distinctions and clarify whether a fracture is primarily “osteoporotic” in nature or due to significant trauma.
In summary, while ICD-10 does not impose extensive, rigid diagnostic specificity requirements, greater specificity is often preferred to accurately reflect severity of illness and costs of care. Important new ICD-10 diagnostic opportunities include documentation of “coma,” coma score, and coma scale components; the distinction between hypoxemic and hypercapnic respiratory failure; and identification of osteoporotic fractures.