Q&A: Surgical complications and misadventures

Q: Consider a patient who received a hysterectomy two days ago and was later admitted for severe acute abdominal pain around the surgical wound. When the wound was reopened, it was discovered that an instrument had been left in her body. The instrument was removed, and the wound was re-sutured. How would coders report this situation with ICD-10-CM codes?

A: External cause codes, found in Chapter 20 of the ICD-10-CM Tabular List of Diseases and Injuries, are used to capture the circumstances surrounding an injury and can be classified as an adverse incident, abnormal reaction, complication, ineffective device associated with adverse incidents, or misadventure. An injury or adverse effect resulting from medical treatment due to a physician error is considered a misadventure; for example, accidentally puncturing an organ during a procedure or leaving a sponge in a surgical wound. Our scenario falls under this category of external causes.

Misadventures are found in categories Y62-Y69:

• Y62.-, Failure of sterile precautions during surgical and medical care
• Y63.-, Failure in dosage during surgical and medical care
• Y64.-, Contaminated medical or biological substances
• Y65.-, Other misadventures during surgical and medical care
• Y66, Nonadministration of surgical and medical care
• Y69, Unspecified misadventure during surgical and medical care

Remember that external cause codes are never listed first. The surgical complication should be listed first with the external cause code listed afterwards.

In the 2025 ICD-10-CM Alphabetic Index, find “foreign body, accidentally left following a procedure, surgical operation, resulting in, specified complication NEC” in order to report the complication. This pathway refers to Chapter 19 subcategory T81.590- (other complications of foreign body accidentally left in body following surgical operation). The final code, T81.590A, has a seventh character to indicate that the patient’s admission was the initial encounter for the complication.

To further specify the surgical complication was pain, find the main term “pain, postoperative” in the Alphabetic Index, which leads to code G89.18 (other acute postprocedural pain). Sequencing guidelines for pain state to list first the code from Chapter 19, then the code from category G89.- to clarify whether the pain was acute or chronic.

There are some complications of care codes that have the external cause included in the code, such as those in subcategory T81.530- (perforation due to foreign body accidentally left in body following infusion or transfusion), meaning an external cause code is not necessary. For our scenario, an external cause code is required in addition to the complication code.

External cause codes are listed in the External Cause of Injuries Index—a separate index from the Alphabetic Index—and is found after the Table of Drugs and Chemicals. But what would we look up in the external cause index? Begin by looking up “misadventure,” “failure,” “nonadministration,” or “wrong” for the main term.

Let’s say we look at the pathway “misadventure, failure, to introduce or to remove tube or instrument” first. This just refers us to the main term “failure.” Following the new main term, we find the appropriate subterm “to remove other tube or instrument,” leading to code Y65.4 (failure to introduce or to remove other tube or instrument).

These three codes are what tell the whole story.

Editor’s note: This question was answered by Terry Tropin, MSHAI, RHIA, CCS-P, an AHIMA-approved ICD-10-CM/PCS trainer who taught medical terminology and medical coding at Montgomery College in Maryland for more than two decades, during the HCPro webinar, “ICD-10-CM Coding for Surgical Complications.” This Q&A originally appeared in JustCoding.