This article appeared in the January issue of the Radiology Coding & Compliance Expert.

Many imaging studies are ordered because the patient is experiencing pain. Once ICD-10 is implemented on October 1 of next year, radiology coders will need to be ready to assign the appropriate codes for these studies. In this article we’ll give you a run-down of how pain is classified in ICD-10, as well as the rules for sequencing the pain codes.

Types of Pain Codes

You can find pain codes in three different places in the ICD-10-CM manual:

  • Pain that points to a disorder of a specific body system is classified in the body system chapters. For example, low back pain is classified in the Musculoskeletal chapter (M54.5) and testicular pain is classified in the Genitourinary System chapter (N50.8).
  • Pain that does not point to a specific body system is classified in the Symptoms and Signs chapter. For example, abdominal pain is classified to category R10.
  • Certain specific types of pain are classified to category G89 (Pain, not elsewhere classified) in the Nervous System chapter.

We’ll discuss all three types of pain codes in this article. Remember that you should always look up the patient’s diagnosis—as documented by the physician—in the ICD-10-CM Index and follow whatever instructions it provides.

Pain of Unspecified Site

Sometimes the radiology department or imaging center will receive a requisition that simply states “Pain” without specifying the location of the pain. This constitutes poor documentation, and the department or facility should ask the ordering physician to provide a more specific clinical history, such as pain in knee joint, flank pain, precordial pain, etc.

In a 2004 letter to the American College of Radiology, the AHA Central Office stated that it is acceptable to assign the code for pain of the site that is being imaged when the requisition does not indicate the location of the pain. For example, if the clinical history for a hand x-ray simply states “Pain,” it is appropriate to code hand pain. However, keep in mind that this guidance was issued for ICD-9-CM, not ICD-10-CM.

The ICD-10-CM Index indicates that pain NOS is reported with code R52 (Pain, unspecified). However, reimbursement for this vague code is likely to be problematic, so try to obtain a more specific diagnosis whenever possible.

Abdominal Pain

ICD-10-CM contains over 30 different codes in category R10 for various types of abdominal and pelvic pain. In addition to the codes for pain in the various parts of the abdomen, there are codes for:

  • Acute abdomen (R10.0): This is sudden, severe abdominal pain, often accompanied by rigidity of the abdomen. Patients with this type of pain are likely to have a condition that requires surgery, such as acute appendicitis, a penetrating duodenal ulcer, or peritonitis.
  • Abdominal tenderness (R10.81-): Tenderness is abnormal sensitivity to touch. While pain is a symptom that the patient reports, tenderness is a reaction that the physician observes while examining the patient’s abdomen.
  • Rebound abdominal tenderness (R10.82-): Tenderness is discomfort that occurs when the examiner presses on the abdomen. Rebound tenderness, on the other hand, occurs when the examiner releases the pressure. It is a sign of peritonitis.
  • Colic (R10.83): Colic is pain that comes in waves. It is associated with contractions of smooth muscles, like those in the intestine or the ureter.

The flank is the side of the patient’s torso below the ribs. Flank pain can be a sign of kidney stones. In the ICD-10-CM Index, the entry for “Pain, flank” shows a note to “see Pain, abdominal.” You must code flank pain as unspecified abdominal pain (R10.9) unless the physician provides additional information about the location of the pain, such as whether it is in the upper or lower portion of the abdomen.

Pelvic pain is classified to code R10.2 (Pelvic and perineal pain). You can use this code for pelvic pain in both male and female patients. It also includes perineal pain, which is pain in the area between a man’s anus and scrotum, or a woman’s anus and vulva.

Here’s an example of code assignment for abdominal pain in ICD-10-CM: The emergency physician orders an ultrasound exam of the abdomen in a patient who has right upper quadrant abdominal pain. The exam does not reveal any cause for the pain. The code assignment is R10.11 (Right upper quadrant pain).

Chest Pain

The ICD-10-CM Index refers you to the code for angina (I20.9) when the patient’s chest pain is described as “ischemic.” However, other types of chest pain are reported with codes from category R07 (Pain in throat and chest). There is an exception for post-thoracotomy pain, which we’ll discuss later.

ICD-10-CM contains codes for the following types of chest pain:

  • Chest pain on breathing (R07.1): This type of pain can be a sign of pulmonary embolism.
  • Precordial pain (R07.2): This is pain in the precordium, which includes the lower chest and epigastric area.
  • Pleurodynia (R07.81): Spasms of pain in the intercostal muscles, which can be a sign of pleurisy (inflammationof the pleural membranes).
  • Intercostal pain (R07.82): This is pain originating in the intercostal nerves, which run between pairs of adjacent ribs.
  • Other chest pain (R07.89): Includes chest wall pain as well as chest pain described as atypical, musculoskeletal, or non-cardiac.

Category G89 Codes

Now let’s look at the types of pain that are classified in the Nervous System chapter. Category G89 includes codes for acute pain, chronic pain, and neoplasm-related pain, as well as codes for two pain syndromes. In order for you to assign these codes, the physician must document that the pain is acute, chronic, or neoplasm-related.

The ICD-10-CM guidelines state that if the cause of the pain is known, you should assign a code for the underlying diagnosis, not the pain code. However, if the purpose of the encounter is to manage the pain rather than the underlying condition, then you should assign a pain code and sequence it first.

For example, a patient is referred to an interventional radiologist for a facet joint injection. The clinical history is chronic low back pain due to degenerative disc disease (DDD) of the thoracic spine with radiculopathy. Because this encounter is for pain control rather than to evaluate or treat the DDD, you should code the pain first. The primary diagnosis is G89.29 (Other chronic pain), and the secondary diagnosis is M51.14 (Intervertebral disc disorders with radiculopathy, thoracic region).

In another example, an interventional radiologist performs kyphoplasty on a patient who has chronic back pain due to an osteoporotic compression fracture of the thoracic spine. Because this encounter is to treat the vertebral compression fracture, you should code only the compression fracture. The code assignment is M80.08- [Age-related osteoporosis with current pathological fracture, vertebra(e)].

The ICD-10-CM guidelines also state you can assign the G89 codes in conjunction with codes from other categories and chapters to provide more detail about acute or chronic pain or neoplasm-related pain. For example, you can assign a G89 code to indicate that the pain is acute or chronic. You should assign the site-specific pain code first unless the purpose of the encounter is pain management, in which case the G89 code is first.

For example, a patient is referred for ankle x-rays for chronic right ankle pain. The exam does not reveal any findings to explain the pain. In this case you need to assign two codes—one for the ankle pain and one from category G89 to indicate that the pain is chronic. Since the purpose of the encounter is not pain management, the site-specific pain code is listed first. The primary diagnosis is M25.571 (Pain in right ankle). Code G89.29 (Other chronic pain) is assigned as a secondary diagnosis.

Trauma Pain

Category G89 contains codes for acute (G89.11) and chronic (G89.21) pain due to trauma. You should not assign these codes if a cause for the pain (i.e., a specific injury) has been identified, except in the unlikely event that the purpose of the encounter is pain management. Also, the physician must document the pain as acute or chronic in order to use these codes.

Postoperative Pain

Category G89 contains four codes for acute and chronic post-thoracotomy pain (G89.12, G89.22) and other postprocedural pain (G89.18, G89.28). The ICD-10-CM guidelines state that you should not code “routine or expected postoperative pain immediately after surgery.” Additionally, in order to assign these codes, the physician must document that the patient’s pain is a complication of the surgery.

If the patient is experiencing pain associated with a specific postoperative complication, such as painful wire sutures, the primary diagnosis is the complication. You can assign a code from category G89 as a secondary diagnosis, if appropriate, to identify whether the pain is acute or chronic.

Neoplasm-Related Pain

Pain caused by a benign or malignant neoplasm in any part of the body is reported with code G89.3 [Neoplasm related pain (acute) (chronic)]. The neoplasm is coded separately. If the purpose of the encounter is pain control, then the pain code should be listed first. Otherwise, the neoplasm is coded first. The ICD-10-CM guidelines state that it is not necessary to assign a site-specific pain code together with G89.3.

For example, a patient is referred for CT of the abdomen with clinical history of “Cancer of the head of the pancreas with increasing cancer pain.” The purpose of the encounter is to evaluate the cancer, not manage the pain, so the cancer is coded first. The primary diagnosis is C25.0 (Malignant neoplasm of head of pancreas). Code G89.3 [Neoplasm related pain (acute) (chronic)] is listed as a secondary diagnosis.

Central Pain Syndrome and Chronic Pain Syndrome

Category G89 contains two codes for pain syndromes. Radiology coders will seldom use these codes, but it is important to understand the difference between them:

Central pain syndrome is defined by the National Institute of Neurological Disorders and Stroke (NINDS) as “a neurological condition caused by damage to or dysfunction of the central nervous system.” Central pain syndrome can occur as a result of stroke, multiple sclerosis, neoplasm, epilepsy, CNS trauma, or Parkinson’s disease. Patients with central pain syndrome may experience localized pain, burning, and/or numbness in specific parts of the body, or throughout the body. ICD-10-CM classifies central pain syndrome to code G89.0 (Central pain syndrome).

Chronic pain syndrome is chronic pain associated with significant psychosocial dysfunction. The psychosocial problems may include depression, drug dependence, complaints that are out of proportion to the physical findings, anxiety, and other manifestations. Chronic pain syndrome is not synonymous with chronic pain. You should code this condition only when the physician specifically documents it. Chronic pain syndrome is reported with code G89.4 (Chronic pain syndrome).

Conclusion

ICD-10 implementation is now less than two years away. If you’d like to take your ICD-10 coding skills to a higher level, we invite you to consider CSI’s ICD-10 products and services. These include a reference manual with exercises (Navigator® for Radiology Diagnosis Coding with ICD-10-CM), CSI’s Specialty Workshop and Training (SWAT) seminar for radiology ICD-10 coding, and CSI’s online learning courses for ICD-10. Or if you have multiple staff to train, a CSI consultant can deliver training at your location. All of our ICD-10 consultants are AHIMA-Approved ICD-10 Trainers. We can help you find the ICD-10 training solution that is right for your organization.