What is Sepsis? | Sepsis Series

This is part 1 in a series focused on coding of sepsis. Sepsis remains one of the most common diagnoses reported, but is also one of the most common found in denials. In this series, we will learn what sepsis is or causes of sepsis, how to sequence the diagnosis in ICD-10-CM, what are the clinical indicators for sepsis, is a query necessary before reporting the diagnosis of sepsis, and how to prevent denials on sepsis records.

What is Sepsis?

Sepsis is a common diagnosis in the United States and it is estimated that between one and three million Americans are diagnosed each year with this condition. Of these, about 22 percent will die on average.

Sepsis is defined as a very serious medical condition and is the overwhelming response to infection. Sepsis progresses rapidly once it has begun and leads to organ damage. In the more serious cases of sepsis, one or more of the patient’s organs will fail. In the worse cases, the patient will develop septic shock, and when that occurs multiple organs will fail and the patient may find it very difficult to recover.

What Causes Sepsis?

Bacteria is the most common cause of sepsis, but it can also be due to fungus or a virus. When this occurs the patient’s blood culture will oftentimes be positive for the causative organism. However, a negative blood culture does not negate the diagnosis of sepsis. When the blood culture is negative, the physician is using other clinical findings of the patient to make the diagnosis of sepsis. The most common clinical findings that are used by physicians to make this diagnosis are:

  • High fever or low temperature (usually >100.4 F (38 C) or hypothermia <96.8 (36C)
  • Tachycardia (usually HR over 90)
  • Confirmed or suspected localized infection
  • Decreased mental status
  • Tachypnea (usually respiratory rate over 20)
  • Chills due to fall in body temperature
  • Hypotension
  • Elevated white count (more than what is seen with just a localized infection usually less than 4,000 or greater than 12,000)

Keep in mind that there are a plethora of clinical indicators, according if Sepsis-1, Sepsis-2 or Sepsis-3 criteria are used.

The number of sepsis cases in the United States increase each year. This is felt to be due to the aging population, increase in antibiotic resistance, and more people diagnosed with conditions that create a weaker immune system. Anyone of any age can develop sepsis, but it is more prevalent in the older population.

How is Sepsis Coded?

Coding the diagnosis of sepsis is a very difficult task for coders since coders see incomplete and contradictory documentation within many of the hospital records. There are many codes in ICD-10-CM for reporting the diagnosis of sepsis depending on the organism or cause. Many times, queries are needed for clarification prior to final coding of the hospital record. We will learn more on querying for sepsis as this series progresses.

The most common sepsis code reported in the United States is A41.9 (Sepsis, unspecified organism). When this is reported, the patient’s blood culture was negative for any causative organism. We will also be looking at sequencing of the diagnosis of sepsis in Part 2 of this series. Please be on the lookout for this next part.

Download our entire Sepsis eBook.

Authored by Kim Boy, RHIT, CDIP, CCS, CCS-P

ICD-10-CM Official Guidelines for Coding and Reporting FY 2020
Coding Clinic for ICD-10-CM/PCS, First Quarter 2018: Page 16
Coding Clinic, Second Quarter 2000 Page: 5


The information contained in this coding advice is valid at the time of posting. Viewers are encouraged to research subsequent official guidance in the areas associated with the topic as they can change rapidly.

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