Coding Sepsis

September is sepsis awareness month and I want to discuss coding sepsis. First I will introduce the concept of medical coding and the definition of sepsis. Skip to half way down for specific coding sepsis examples.

What is Medical Coding?

Medical coding is the transformation of diagnoses and procedures into a set of universal alphanumeric codes. It allows for uniform documentation. Many physicians have to code for themselves. Suffice it to say, medical coding is not taught in medical school. We start to “wing it” in residency and if not then, in our first year of practice. I have previously discussed one of my early frustrations with coding.

Even though some of us have access to professional medical coders it’s up to us to use the correct terminology in our documentation for the coders to translate into codes. The coders cannot interpret lab or imaging results or infer from what we have not clearly stated. I unfortunately have had to code my documentation. Thus, I’m working on mastering coding terminology for my often seen diagnoses. The website ICD10Data and the iPhone app ICD10 Consult are helpful in this regard.

What is Sepsis?

Sepsis is a major public health concern. It is a diagnosis I manage daily and have discussed previously here and here.

Sepsis is a syndrome of dysregulation induced by infection. Reported incidence of sepsis is increasing because of our ageing population with their higher burden of medical comorbidities but also because of our greater awareness of the condition.

Many of us in clinical practice use the SIRS criteria defined in 1991 in defining sepsis. SIRS stands for systemic inflammatory response syndrome. SIRS due to infection is sepsis. Sepsis complicated by organ dysfunction is severe sepsis. Severe sepsis can progress to septic shock defined as “sepsis-induced hypotension persisting despite adequate fluid resuscitation”. Unfortunately, SIRS definitions leads us to identify more people as septic when they might not be.

There have been recent clinical revisions to the definition of sepsis. The Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3) published earlier this year says “sepsis should be defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection.” Septic shock should be defined as “a subset of sepsis in which particularly profound circulatory, cellular, and metabolic abnormalities are associated with a greater risk of mortality than with sepsis alone”. Sepsis-3  introduced a bedside clinical score termed quick SEPSIS RELATED ORGAN FAILURE ASSESSMENT or quickSOFA (qSOFA). qSOFA is designed to identify patients at risk of sepsis specifically those at risk of deteriorating. It’s a mortality predictor and is not supposed to be part of the sepsis definition nor replace the SIRS criteria.

In either case both SIRS and qSOFA are poor markers for sepsis in clinical practice.

Coding Sepsis

Seeing how difficult it is to define sepsis, is it any wonder that we have difficulty coding sepsis? Much of the confusion is due to these changing terminology and evolving definitions. The transition from ICD-9 to ICD-10 also introduced changes to coding sepsis. In addition there is a clear disconnect between terminology used by clinicians and that used by coders. For me, that’s most frustrating. Here, I attempt to bridge those differences.

Local infection

Since sepsis involves an infection being present, suspected or confirmed, in coding sepsis it is important to code the source of infection first. Sometimes the local infection eg. urinary tract infection (UTI) does not proceed to sepsis. It is not unusual for an infection to be accompanied with symptoms such as leukocytosis and/or fever. A nurse driven sepsis screening tool will identify such a patient as septic when that is not the clinical assessment of the physician. This is one way the SIRS definition is problematic. But let’s talk about coding shall we?

Example 1: A patient is admitted with UTI. Urine culture grows E.coli. You document E.coli UTI.

• N39.0 Urinary tract infection, site not specified
• B96.20 Unspecified Escherichia coli (E.coli) as the cause of diseases classified elsewhere

Example 2: A patient is admitted with UTI, fever, leukocytosis, tachypnea. Urine and blood cultures grow E.coli. You document E.coli sepsis due to UTI.

• A41.51 Sepsis due to Escherichia coli (E.coli)
• N39.0 Urinary tract infection, site not specified

Example 3: A patient is admitted with UTI. Urine culture grows E.coli. Two days later the patient develops fever, leukocytosis, tachypnea. You document E.coli sepsis due to UTI.

• N39.0 Urinary tract infection, site not specified
• A41.51 Sepsis due to Escherichia coli (E.coli)

Tip: If the admitting diagnosis is a localized infection and the patient does not develop sepsis until after the admission, code the localized infection first. If the patient is septic at the time of admission, code that first.

Bacteremia

Bacteremia is a tough one. Many clinicians in practice use bacteremia to show how sick a patient is. But in coding terminology bacteremia is simply a laboratory finding of “bacteria in the blood”. It does not confer any degree of illness in the patient. Most patients we see with “bacteria in the blood” though are symptomatic as a result. They are in fact septicemic (see below). Thus, I generally use bacteremia (R78.81) to code for coagulase-negative staph bacteremia which we clinicians routinely term CoNS contaminant.

Example: A patient is admitted with UTI. She doesn’t look sick but urine and blood cultures grow E.coli. You document E.coli bacteremia due to UTI.

• N39.0 Urinary tract infection, site not specified
• R78.81 Bacteremia (abnormal culture blood or positive culture blood)
• B96.20 Unspecified Escherichia coli (E.coli) as the cause of diseases classified elsewhere

Tip: If bacteremia presents with a localized infection, code the local infection first, then the bacteremia, then the organism.

SIRS (Systemic Inflammatory Response Syndrome)

As a clinician, documenting SIRS by itself is not very insightful. We should decide if the SIRS is due to infection or if it is non-infectious. In ICD-10, “SIRS due to infection” is sepsis and so we should document sepsis instead. SIRS in ICD-10 is best used for non-infectious origin including trauma, pancreatitis, cancer, drug reaction etc.

Example 1: A patient presents with epigastric abdominal pain, fever, tachypnea, leukocytosis and is diagnosed with pancreatitis. You document SIRS due to pancreatitis.

• K85.90 Acute pancreatitis without necrosis or infection, unspecified
• R65.10 Systemic inflammatory response syndrome (SIRS) of non-infectious origin without organ dysfunction

Example 2: A patient presents with epigastric abdominal pain, fever, tachypnea, leukocytosis, is diagnosed with pancreatitis and later develops respiratory distress. You document SIRS due to pancreatitis with acute respiratory failure.

• K85.90 Acute pancreatitis without necrosis or infection, unspecified
• R65.11 Systemic inflammatory response syndrome (SIRS) of non-infectious origin with organ dysfunction
• J96.00 Acute respiratory failure, unspecified whether with hypoxia or hypercapnia

Tip: Code the process first, then the SIRS. If there is organ dysfunction, code that after.

Urosepsis

Doesn’t exist in coding terminology.

Sepsis Syndrome

Doesn’t exist in coding terminology.

Septicemia

Septicemia is the coding term for what many clinicians call bacteremia. A patient with septicemia has systemic disease associated with the presence of bacteria in the blood. In ICD-10 septicemia and sepsis are interchangeable. For example, A41.51 codes for either E.coli sepsis or E.coli septicemia.

Sepsis

Sepsis is the systemic inflammatory response to infection. Even though septicemia and sepsis code the same in ICD-10 you don’t have to have positive blood cultures to have sepsis.

Example 1: A patient is admitted with UTI, fever, leukocytosis, tachypnea. Urine and blood cultures grow E.coli. You document E.coli sepsis due to UTI.

• A41.51 Sepsis due to Escherichia coli (E.coli)
• N39.0 Urinary tract infection, site not specified

Example 2: A patient is admitted with UTI, fever, leukocytosis, tachypnea. Urine and blood cultures grow Candida. You document Candidemia due to UTI.

• B37.7 Candidal sepsis (also candidemia or disseminated candidiasis)
• B37.49 Other urogenital candidiasis

Tip: The A40.- through A41.9 codes are for sepsis due to bacteria. Remember that other microbes can cause sepsis too.

Severe Sepsis

Severe sepsis is sepsis with organ dysfunction (R65.-). Not only do we need to document each dysfunctional organ, we also need to state that the dysfunction “is due to” the sepsis. There is no code for “multi-organ dysfunction”. You have to attribute the organ dysfunction to sepsis to use the severe sepsis code (R65.20) and then code for the organ dysfunction.

Example 1:  A patient is admitted with UTI, fever, leukocytosis, tachypnea, tachycardia. Urine and blood cultures grow E.coli. The patient’s creatinine is 4.0 and they need BIPAP.  You document E.coli sepsis due to UTI, acute kidney injury due to sepsis, acute hypoxic respiratory failure due to sepsis.

• A41.51 Sepsis due to Escherichia coli (E.coli)
• R65.20 Severe sepsis without septic shock
• N39.0 Urinary tract infection, site not specified
• J96.01 Acute respiratory failure with hypoxia
• N17.9 Acute kidney failure, unspecified

Example 2: A patient is admitted with UTI, fever, leukocytosis, tachypnea, tachycardia. Urine and blood cultures grow E.coli. The patient’s creatinine is 4.0 and they need BIPAP. You document E.coli sepsis due to UTI, acute kidney injury, acute hypoxic respiratory failure.

• A41.51 Sepsis due to Escherichia coli (E.coli)
• N39.0 Urinary tract infection, site not specified
• J96.01 Acute respiratory failure with hypoxia
• N17.9 Acute kidney failure, unspecified

Example 3: A patient is admitted with UTI, fever, leukocytosis, tachypnea, tachycardia. Urine and blood cultures grow E.coli. The patient’s creatinine is 4.0 and they need BIPAP. You document E.coli sepsis due to UTI with multi-organ failure.

• A41.51 Sepsis due to Escherichia coli (E.coli)
• N39.0 Urinary tract infection, site not specified

Example 4: A patient is admitted with UTI, fever, leukocytosis, tachypnea, tachycardia. Urine and blood cultures grow E.coli. The patient’s creatinine is 4.0 and they need BIPAP. You document severe sepsis/E.coli sepsis due to UTI.

• A41.51 Sepsis due to Escherichia coli (E.coli)
• N39.0 Urinary tract infection, site not specified

Example 5: A patient is admitted with UTI, fever, leukocytosis, tachypnea, tachycardia. Urine and blood cultures grow E.coli. The patient’s creatinine is 4.0 and they need BIPAP. You document severe sepsis/E.coli sepsis due to UTI with multi-organ failure.  

• A41.51 Sepsis due to Escherichia coli (E.coli)
• N39.0 Urinary tract infection, site not specified

Tip: Notice how the patient is identical in each example but the codes are different because of the documentation? Since coding ultimately affects reimbursement this is why many hospitals hire medical coders to nudge physicians to document more accurately. Reimbursement for the documentation of Example 5 is much less than for Example 1 even though it’s the same patient getting the same care.

Septic Shock

Septic shock is severe sepsis associated with hypotension/circulatory failure. It’s a form of organ failure. As such it is a secondary code. Septic shock is not a principal diagnosis in medical coding although us clinicians seem to think that it is.

Example:  A patient is admitted with UTI. She has fever, leukocytosis, tachypnea, tachycardia, and hypotension refractory to fluids. Urine and blood cultures grow E.coli. The patient also has acute kidney injury and acute hypoxic respiratory failure. You document septic shock, E.coli sepsis due to UTI, acute kidney injury due to sepsis, acute hypoxic respiratory failure due to sepsis.

• A41.51 Sepsis due to Escherichia coli (E.coli)
• R65.21 Severe sepsis with septic shock
• N39.0 Urinary tract infection, site not specified
• J96.01 Acute respiratory failure with hypoxia
• N17.9 Acute kidney failure, unspecified

Tip: Septic shock is a secondary diagnosis.

Sepsis Due to a Device or Sepsis, Post-procedural

Postprocedural septic shock falls under T81.12-.

Example 1: A patient is admitted with UTI, fever, leukocytosis, tachypnea hours after having an indwelling Foley catheter placed. Urine and blood cultures grow E.coli. You document E.coli sepsis due to UTI due to indwelling Foley catheter.

• T83.51XA Infection and inflammatory reaction due to other urinary catheter, initial encounter
• A41.51 Sepsis due to Escherichia coli (E.coli)
• N39.0 Urinary tract infection, site not specified

Example 2: A patient is admitted with UTI, fever, leukocytosis, tachypnea hours after having an indwelling Foley catheter placed. Urine and blood cultures grow E.coli. You document E.coli sepsis due to complicated UTI.

• A41.51 Sepsis due to Escherichia coli (E.coli)
• N39.0 Urinary tract infection, site not specified

Tip: When coding, the complication code comes first. You must define what the complication is. “Complicated UTI” does not exist. Documenting “complicated UTI” will land you an N39.0 which incidentally is the same code for pyuria as well as for asymptomatic bacteriuria.

Conclusion

Coding in general is difficult when you don’t understand, let alone speak the language. Furthermore, coding sepsis even when you have a rudimentary understanding is complicated. I hope my examples show how crucial it is to understand and document with coding language to give an accurate picture of the true complexity of a patient’s medical presentation and thus their risk of mortality.

Do you agree or not? Share your thoughts.