Coding for injuries and external causes

Coding for injuries

When you code injuries, assign separate codes for each injury unless a combination code is provided, in which case the combination code is assigned. Code T07 Unspecified multiple injuries should not be assigned in the inpatient setting unless documentation for a more specific code is not available. Traumatic injury codes (S00–T14.9) are not to be used for normal, healing surgical wounds or to identify complications of surgical wounds.

The code for the most serious injury, as determined by the provider and the focus of treatment, is sequenced first.

Superficial injuries

Superficial injuries, such as abrasions and contusions, are not coded when they are associated with more severe injuries at the same site.

Primary injury with damage to nerves or blood vessels

When a primary injury results in minor damage to peripheral nerves or blood vessels, the primary injury is sequenced first. Any additional code or codes for injuries to nerves and the spinal cord or injury to vessels or nerves are coded as secondary.

Coding for traumatic fractures

The principles of multiple coding of injuries should be followed in the coding of fractures. Fractures of specified sites are coded individually by site in accordance with the level of detail furnished by the health record. The traumatic fracture categories include the following: A02, S12, S22, S32, S42, S49, S52, S59, S62, S72, S82, S89, and S92. A fracture not indicated as open or closed should be coded as closed. A fracture not indicated as displaced or not displaced should be coded as displaced.

Coding for burns and corrosions

The same principles for multiple coding apply to burns. Code each burn separately unless specific combination codes are given in the Tabular List. There are many combination codes. Most burn codes are found in Chapter 19 (Injury, Poisoning, and Certain Other Consequences of External Origin); the applicable codes are T20–T32. Because burns are coded by site and degree and by the extent of body surface involvement, all burn cases should have at least two codes and a third if the wound is infected. Other types of wounds, lacerations, punctures, and so on, use a different fifth character to show that they are infected and, therefore, complicated. However, burn codes use the fifth character for other information. Therefore, these diagnoses require an additional code to indicate infection.

The ICD-10-CM makes a distinction between burns and corrosions. The burn codes are used for the following: thermal burns (except sunburns) caused by a heat source, such as a fire or hot appliance; burns resulting from electricity; and burns resulting from radiation. Corrosions, on the other hand, are burns caused by chemicals. The guidelines are the same for burns and corrosions.

Current burns (T20–T25) are classified by depth, extent, and burn agent (X code). Depth is categorized as first degree (redness), second degree (blistering), and third degree (full-thickness involvement). Burns of the eye and internal organs (T26–T28) are classified by site but not by degree.

Coding for drug toxicity

Chapter 19 also includes coding for the following drug toxicity classifications:

• Poisoning (T36–T50): A reaction to the improper use of a medication, which can be the result of an error made by the prescribing provider, intentional overdose, interaction with drugs or alcohol, or a reaction caused when a non prescribed medication interacts with a prescribed and properly administered medication.
• Adverse effect: An unfavorable side effect that occurs even though medication is correctly prescribed and properly administered.
• Underdosing: Patient takes less of a medication than is prescribed by the provider or by the manufacturer’s instructions.
• Toxic effect: Patient ingests or comes in contact with a toxic substance.

Codes in categories T36–T65 are combination codes that include the substance taken and the intent. No additional external cause code is required for poisonings, toxic effects, adverse effects, and underdosing codes. When you are coding, do not code directly from the Table of Drugs and Chemicals. Always refer back to the Tabular List.

Coding for external causes of morbidity

External cause codes are intended to provide data for research on injuries and evaluation of injury prevention strategies. These codes capture the following specifics:

• How the injury or health condition happened (cause)
• The intent (unintentional or accidental; or intentional, such as suicide or assault)
• The place where the event occurred
• The activity of the patient at the time of the event and the person’s status (e.g., civilian, military)

These codes are often used for workers’ compensation claims. An external cause of morbidity code can never be reported alone. It is reported in addition to the injury code and is sequenced as the last code.

Place of occurrence guideline

Codes from category Y92, Place of occurrence of the external cause, are secondary codes. They are used after other external cause codes to identify the location of the patient at the time of the injury or other condition. A place of occurrence code is used only once at the initial encounter for treatment. No seventh character is used in Y92 codes. Only one code from category Y92 should be recorded on the patient’s health record. Do not use the place of occurrence code Y92.9 (unspecified place or not applicable) if the place is not stated or if it is not applicable.

Activity codes

Category Y93 Activity codes are used to define the activity the patient was involved in at the time of injury or when the health condition developed. Only one code from category Y93 should be recorded in the patient’s health record. An activity code should be used in conjunction with a place of occurrence code (Y92). The activity codes are not applicable to poisonings, adverse effects, misadventures, or sequelae.

Do not assign code Y93.9 Unspecified activity if the activity is not stated.

A code from category Y93 can be used with external cause (Y99) and occurrence (Y92) codes if identifying the activity provides additional information about the event. For example, you are coding a closed ankle fracture that occurred while the patient was playing soccer in a public park. To begin, you must identify what should be coded first. In this case, the ankle fracture is coded first: S92.111A Displaced fracture of neck of right talus (remember, “A” indicates initial encounter). The second code is the activity code; the patient was playing soccer, so the code for this activity is Y93.66 Activity, soccer. Remember, if the report did not state an activity, do not add Y93.9 Unspecified activity.

Finally, when an activity code is used, a place of occurrence code should also be used. In this scenario, the patient was playing in a public park; therefore, the place of occurrence code is Y92.830 Public park.