February 28, 2011

Coding for Postoperative Wound Infection
For the Record
Vol. 23 No. 4 P. 28

A postoperative wound infection occurs in the tissues of an incision or operative area at any point from one day to many years after a surgical procedure. However, it most commonly occurs between five and 10 days after surgery. From an ICD-9-CM coding perspective, there is no time limitation regarding the assignment of a complication code. In other words, if the physician states the condition causing the admission is related to a prior surgery, then it would be appropriate to assign a complication code for this encounter regardless of when the surgery occurred.

Postoperative wound infection is classified to ICD-9-CM code 998.59, Other postoperative infection. Code 998.59 also includes postoperative intra-abdominal abscess, postoperative stitch abscess, postoperative subphrenic abscess, postoperative wound abscess, and postoperative septicemia.

A coding directive under code 998.59 indicates the need to use an additional code to identify the infection. This is supported by the official coding guidelines for complications of surgery and other medical care, which states, “If the complication is classified to the 996-999 series and the code lacks the necessary specificity in describing the complication, an additional code for the specific complication should be assigned” (ICD-9-CM Official Guidelines for Coding and Reporting, effective October 1, 2010, page 87-88). For example, if a patient is admitted with cellulitis of the operative wound, having undergone a colon resection five days before, code 998.59 is assigned and sequenced first, followed by code 682.2, Cellulitis of trunk. It is appropriate to add code 682.2 in this case to identify the specific type of infection, which is not identified in code 998.59.

Possible causes of postoperative wound infections include poor preoperative preparation, wound contamination, poor antibiotic selection, and an immunocompromised patient’s inability to fight off infection. The four categories of wound contamination are clean wounds with no gross contamination, lightly contaminated wounds (stomach or biliary surgeries), heavily contaminated wounds (intestinal surgeries), and infected wounds in which infection is obviously present prior to surgical incision.

Postoperative Fever
It is normal for a patient to have a low-grade temperature for one to two days after surgery due to the body’s response to a foreign invasion. The following is what is expected following surgery:

• a 100˚F temperature for the first two days after surgery;

• post-op antibiotics ordered the day of surgery;

• incentive spirometry as routine post-op care; and
• nurses will get the patient out of bed and moving around shortly after the procedure.

The fever would be considered clinically significant if one of the following occurs:

• the temperature spikes in the first two days after surgery (above 101˚F) and the physician begins to evaluate it with cultures or begins/changes to IV antibiotics (rather than the routine post-op antibiotics); or

• the temperature lasts longer than 48 hours after surgery.

To determine the underlying cause of the fever, physicians remember the “five Ws” of postoperative fever:

• wind (atelectasis), which most often presents itself within one to two days postoperatively;

• water, a urinary tract infection from the Foley catheter or urine sitting in bladder due to poor voiding or retention that most often occurs three to five days after surgery;

• walking, deep venous thrombosis may occur four to six days following surgery (Walking the patient on the first day following surgery is the best way to prevent this complication.);

• wound, as a wound infection most commonly occurs five to seven days postoperatively; and

• wonder drugs, as some medications can cause fever that may occur more than seven days after surgery.

If the cause of the fever is identified, then assign a code for that condition instead of the fever. If the physician states only “postoperative fever” and doesn’t identify the source and it is evaluated, monitored, or treated, then assign code 780.62.

Coding and sequencing for postoperative wound infection are dependent on the physician documentation in the medical record and application of the Official Coding Guidelines for inpatient care. Also, use specific AHA Coding Clinic for ICD-9-CM and American Medical Association CPT Assistant references to ensure complete and accurate coding.

— This information was prepared by Audrey Howard, RHIA, of 3M Consulting Services. 3M Consulting Services is a business of 3M Health Information Systems, a supplier of coding and classification systems to more than 5,000 healthcare providers. The company and its representatives do not assume any responsibility for reimbursement decisions or claims denials made by providers or payers as the result of the misuse of this coding information. More information about 3M Health Information Systems is available at www.3mhis.com/or by calling 800-367-2447.

Coding for Complications of Care in ICD-10-CM

The following is a summary of the ICD-10-CM complication of care coding guidelines from the ICD-10-CM Official Guidelines for Coding and Reporting:

• Code assignment is based on the physician’s/provider’s documentation of the relationship between the condition and the procedure.

• Assign the appropriate code from chapter 19 (Injury, Poisoning and Certain Other Consequences of External Causes) for a patient having pain associated with devices, implants, or grafts left in a surgical site. The codes for pain due to a medical device are located in the T code section in chapter 19 of ICD-10-CM. Use an additional code from category G89 to identify acute or chronic pain due to the presence of the device, implant, or graft.

• Assign a code for a transplant complication (category T86) if a patient is admitted with a condition that affects the function of the transplanted organ. A preexisting condition or a condition that develops after the transplant is coded as a transplant complication if it affects the function of the transplanted organ. Assign the T86 code first, followed by a code for the condition.

• A patient with a transplanted kidney may still have a certain degree of chronic kidney disease (CKD) since the transplant may not fully restore kidney function. Therefore, code T86.1- should not be assigned for patients who have CKD in a transplanted organ. This is an exception to the above coding guideline. It would be appropriate to assign code T86.1- for transplant failure, rejection, or another complication that affects the function of the transplanted kidney.

• Sometimes, for certain T codes, there is no need for an external cause code that indicates the type of procedure because the external cause information is included in the T code.

• Some complication-of-care codes are found in the body system chapters as opposed to chapter 19. Sequence the complication-of-care code first, followed by a code for the specific complication, if applicable. For example, postoperative aspiration pneumonia is classified to codes J95.89 and J69.0.

• Ventilator-associated pneumonia is classified to code J95.851 and is assigned only when the physician documents this diagnosis. It is not assigned when the patient has pneumonia and is on a ventilator. The physician must document that the pneumonia is ventilator-associated pneumonia. It is appropriate to assign a code to identify the organism involved, if known. However, do not assign an additional code for the type of pneumonia (eg, Pseudomonas pneumonia).

• If the patient is admitted with pneumonia and develops ventilator-associated pneumonia during the hospital stay, then it is appropriate to assign a code for both conditions. The pneumonia would be sequenced as the principal diagnosis.

— Audrey Howard