Coding of Sepsis, Severe Sepsis, and Septic Shock – ICD-10 Guidelines

Sepsis is a life-threatening complication that develops when the chemicals the immune system releases into the bloodstream to fight an infection cause inflammation throughout the body instead. Coding of Sepsis and Severe Sepsis can be complicated and physicians would do well to rely on medical coding services to report these conditions. Experienced coders carefully review ICD-10 guidelines and clinical documentation to assign the right codes for sepsis, severe sepsis and septic shock.

While ICD-9 had codes whose description included the word “septicemia,” there is no code for septicemia in ICD-10. Physicians should use the term “bacteremia” if there is evidence of bacteria circulating in the blood. Since ICD-10 utilizes combination coding, sepsis without acute organ failure requires only one code, that is, the code for the underlying systemic infection (A40.0 – A41.9). Complete and accurate coding of severe sepsis, however, requires a combination of at least two codes – the first code sequenced to identify the underlying organism (Sepsis, A40.0 – A41.9) or cause of the sepsis (postprocedural infection, trauma, or burn), followed by a code indicating the extent to which the septic condition has progressed, that is, severe sepsis with or without septic shock.

Sepsis

• If the underlying infection or causative organism is not further specified, code A41.9, Sepsis unspecified organism should be assigned.
• For a diagnosis of sepsis, the appropriate code for the underlying systemic infection should be assigned, for instance, A41.51 (Sepsis due to Escherichia coli). One combination code is used to capture the underlying systemic infection and the body’s inflammatory response to it.
• A code from subcategory R65.2, Severe sepsis, should not be assigned unless severe sepsis or an associated acute organ dysfunction is documented.

ICD-10 guidelines state that the coder should query the provider in the following instances:

• If the blood culture is negative or inconclusive, as this does not rule out the presence of sepsis.
• If the term ‘urosepsis’ is used in the documentation, as urosepsis is not considered synonymous with sepsis.
• If the documentation is not clear as to whether an acute organ dysfunction is related to the sepsis or another medical condition.

If it is reported that the patient has sepsis and associated acute organ dysfunction or multiple organ dysfunction (MOD), the instructions for coding severe sepsis should be followed.

Severe Sepsis

R65.2, Severe sepsiswithout septic shock

Severe sepsis is a result of both community-acquired and health care-associated infections. It is reported that pneumonia accounts for about half of all cases of severe sepsis, followed by intraabdominal and urinary tract infections.

A minimum of two codes are needed to code severe sepsis. First, an appropriate code has to be selected for the underlying infection, such as, A41.51 (Sepsis due to Escherichia coli), and this should be followed by code R65.2, severe sepsis.

• If the causal organism is not documented, code A41.9, Sepsis, unspecified organism, should be assigned for the infection.
• An additional code should be assigned for the organ dysfunction severe sepsis is causing, such as, N17.0 Acute kidney failure with tubular necrosis.
• If a patient has sepsis and an acute organ dysfunction, but the medical record documentation indicates that the acute organ dysfunction is related to a medical condition other than the sepsis, a code from subcategory R65.2, Severe sepsis should not be assigned.
• The provider should be queried if the documentation is not clear as to whether an acute organ dysfunction is related to the sepsis or another medical condition.

Septic Shock

R65.21, Severe sepsis with septic shock

As it typically refers to circulatory failure associated with severe sepsis, septic shock indicates a type of acute organ dysfunction.

The code for septic shock cannot be assigned as a principal diagnosis. For septic shock, the code for the underlying infection should be sequenced first, followed by code R65.21, Severe sepsis with septic shock or code T81.12, Postprocedural septic shock. Additional codes are also required to report other acute organ dysfunctions.

Sequencing of Severe Sepsis

•  If severe sepsis is present on admission, and meets the definition of a principal diagnosis, the underlying systemic infection should be assigned as principal diagnosis followed by the appropriate code from subcategory R65.2, following the sequencing rules in the Tabular List. A code from subcategory R65.2 can never be assigned as a principal diagnosis.
• If the severe sepsis was not present on admission but develops during the encounter, the underlying systemic infection and the appropriate code from subcategory R65.2 (Severe sepsis) should be assigned as secondary diagnoses.
• It could happen that severe sepsis is present on admission, but the diagnosis may not be confirmed until sometime after admission. The provider should be queried if the documentation is not clear whether severe sepsis was present on admission.

Sepsis and Severe Sepsis with a Localized Infection

•  If a patient is admitted with both sepsis or severe sepsis and a localized infection, such as pneumonia or cellulitis, a code(s) for the underlying systemic infection should be assigned first and the code for the localized infection should be reported as a secondary diagnosis.
• If severe sepsis is present, a code from subcategory R65.2 should also be assigned as a secondary diagnosis.
• If the reason for the admission is a localized infection, such as pneumonia, and sepsis/severe sepsis does not develop until after admission, the localized infection should be reported first, followed by the appropriate sepsis/severe sepsis codes.

Sepsis due to a Postprocedural Infection

• Documentation of causal relationship: The provider’s documentation of the relationship between the infection and the procedure should determine code assignment.
• Sepsis due to a postprocedural infection: For such cases, the postprocedural infection code should be coded first, such as: T80.2, Infections following infusion, transfusion, and therapeutic injection, T81.4, Infection following a procedure, T88.0, Infection following immunization, or O86.0, Infection of obstetric surgical wound. This should be followed by the code for the specific infection. If the patient has severe sepsis, the appropriate code from subcategory R65.2 should also be assigned with the additional code(s) for any acute organ dysfunction.
• Postprocedural infection and postprocedural septic shock: If the patient develops postprocedural infection which has resulted in severe sepsis, the code for the precipitating complication should be assigned first, such as, T81.4, Infection following a procedure, or O86.0, Infection of obstetrical surgical wound. This should be followed by code R65.20, Severe sepsis without septic shock and a code for the systemic infection.

Sepsis and severe sepsis associated with a noninfectious process (condition)

• If the physician documents sepsis or severe sepsis as associated with a noninfectious condition, such as a burn or serious injury, and this condition meets the definition for principal diagnosis, the code for the noninfectious condition should be assigned first, followed by the code for the resulting infection. If severe sepsis is present, a code from subcategory R65.2 should also be assigned with any associated organ dysfunction(s) codes.
• If the infection meets the definition of principal diagnosis, it should be sequenced before the non-infectious condition. If both the associated non-infectious condition and the infection meet the definition of principal diagnosis, either may be assigned as principal diagnosis.
• When a non-infectious condition leads to an infection resulting in severe sepsis, assign the appropriate code from subcategory R65.2, Severe sepsis.
• It is not necessary to additionally assign a code from subcategory R65.1, Systemic inflammatory response syndrome (SIRS) of non-infectious origin, when a non-infectious condition leads to an infection resulting in severe sepsis.

ICD-10 codes provide the opportunity to more accurately report the clinical significance and increased complexity of treating severe sepsis when presenting with septic shock. To assign the appropriate codes, the coding team in reliable medical coding companies will carefully study provider documentation for signs and symptoms and/or clinical indicators that support the diagnosis of sepsis, and query providers on any lack of clarity. They will also code claims following ICD-10 guidelines.