Assigning the appropriate diagnosis codes is an integral part of your burn coding. ICD-9 classifies burns by depth, extent and agent if appropriate, says Katie Cianciolo, RHIA, CCS, CCS-P, coding consultant. With burns, you will usually list at least two, and often three, codes. You should follow six guidelines when assigning burn diagnosis codes, Cianciolo says:
1. List first the highest burn degree.
2. List only the most severe burn degree when burns are at the same site but different degrees.
3. Use category 949.x, Burn unspecified, rarely because it is vague.
4. Assign a code from category 948 according to the extent of body surface involved:
Use a single code if the burn site is unspecified.
Use as an additional code if the burn site is specified.
Use as an additional code when a third-degree burn involves more than 20 percent of body surface.
Use a fifth-digit subclassification to identify the percentage of body involved in a third-degree burn, and assign "0" as the fifth digit when less than 10 percent or no body surface includes a third-degree burn.
5. Code conditions identified as late effects to the residual condition.
6. Assign two codes for infected burns or other injuries that occur with the burn.
Following these guidelines, you should first look at ICD-9 codes from the 940-949 series to identify the location, says Marty Herman, MD, FAAP, FACEP, associate professor of pediatrics at UT College of Medicine, Memphis, Tenn. The fourth digit is important because it designates the severity of the burn. You should code for the most severe level of burn documented in the record. For example, take the 942.x series (Burn of trunk):
942.0x Unspecified degree
942.1x Erythema (first degree)
942.2x Blisters, epidermal loss (second degree)
942.3x Full-thickness skin loss (third degree NOS)
942.4x Deep necrosis of underlying tissues (deep third degree) without mention of loss of a body part
924.5x Deep necrosis of underlying tissues (deep third degree) with loss of a body part.
ICD-9 also designates a fifth digit that specifies the body part affected. For example, glance at the fifth digits for the same 942 series:
0 Trunk, unspecified site
1 Breast
2 Chest wall, excluding breast and nipple
3 Abdominal wall
4 Back (any part)
5 Genitalia
9 Other and multiple sites of trunk.
You should use codes from the 948.xx series, which designate the extent of body surface involved, as secondary diagnosis codes. This code series requires a fourth and fifth digit. The fourth digit details the total percentage of the body that is burned, while the fifth digit indicates the percentage of the body affected by third-degree burns. ICD-9 indicates under each code which fifth digit may be used with it.
Suppose a patient presents with second- and third- degree burns over 30 percent of his body with the third-degree burns taking up 20 percent. In this instance, you would report 948.32 (30-39 percent of body surface; 20-29 percent third degree). The physician should carefully document the percentage of body burned, the body parts affected, and the severity of the burn.
If the burn is accidental, you should report an E code for accidents by fire and flames (E890-E899), Herman says. E codes may help determine if a third-party payer should be liable for the costs of treatment. For example, if a woman was burned by dropping boiling water, you should use E924.0 (Accident caused by hot substance or object, caustic or corrosive material, and steam; hot liquids and vapors, including steam). Be aware, however, that not all payers recognize E codes. Herman points out other important E codes that you should not forget:
E921.x Accident caused by explosion of pressure vessel
E922.x Accident caused by firearm, and air gun missile
E923.x Accident caused by explosive material
E924.x Accident caused by hot substance or object, caustic or corrosive material, and steam
E925.x Accident caused by electric current
E926.x Exposure to radiation.