Anatomy and Physiology in ICD-10
The tenth revision of the International Classification of Diseases (ICD-10) brings many changes to coding in the United States. It not only increases the amount of codes available for use, it will also require, among many things, an in-depth understanding of anatomy and pathophysiology. Code selections may be based on the site of the condition or injury (anatomy) or by the disease process (pathophysiology), and the stages of healing. Without an understanding of these, the user will find it difficult to select the appropriate code.
Take a look at the injury section as an example, many of these codes require 7 characters and it may be necessary to know the type of injury, site, laterality, and episode of care. For example, in ICD-9-CM there is one choice for closed fracture of the shaft of the radius (813.21). In ICD-10-CM there are 270 code choices for this injury. The code is assigned based on:
- Type of fracture (greenstick, transverse, spiral, etc.)
- Displaced or nondisplaced
- Right, left, or unspecified side
- Episode of care (initial, subsequent, or sequela)
- Stage of healing (for subsequent encounters)
- Delayed healing
You can see that without an understanding of the various types of fractures, and the healing process involved, the user may have a difficult time with code selection. There may be temptation to use the unspecified code if the information is omitted from the note; however, the requirement is to always use the code that most accurately describes the injury.
ICD-10-CM has an increased amount of combination codes compared to ICD-9-CM. Knowledge of anatomy and pathophysiology in the areas where combination codes exist will help to user to understand the relationship between the two conditions. In ICD-9-CM two codes were required to report coronary atherosclerosis of autologous vein bypass graft with intermediate coronary syndrome (unstable angina) – 414.02 and 411.1. In ICD-10-CM the same condition would be reported with the combination code I25.710 – Atherosclerosis of autologous vein coronary artery bypass graft(s) with unstable angina pectoris.