If there is any certainty in the health care industry today, it is that things will change. For example, diagnostic documentation criteria have seen enough recent changes to necessitate an update for hospitalists. Some of these changes are to conditions that have been written about previously in this column.
As discussed in my January 2011 column, the current clinical definition of sepsis is SIRS (systemic inflammatory response syndrome) due to confirmed or suspected infection. The diagnosis of sepsis in an adult is established when an ill-appearing patient with an infection has two or more of the requisite criteria (see sidebar) that, in the physician's judgment, are caused by the infection. The first four criteria in the list are probably the most familiar and are often given the greatest weight by clinicians. Notice too that a positive blood culture is not a diagnostic criterion, although bacteremia would certainly be very strong confirmatory evidence.
A criterion should not be used to diagnose and document sepsis if it can be “easily explained” by another condition. For example, if the patient has a severe urinary tract infection and an acute exacerbation of chronic obstructive pulmonary disease (COPD), a respiratory rate of 24 could be easily explained by the COPD. In a patient with pneumonia and new-onset atrial fibrillation, a heart rate of 140 would likely be due to the arrhythmia. The determination of what is “easily explained” is left entirely to the physician's best clinical judgment.
In September 2011 there was a change in official coding guidance that now makes it important to document what infection is believed to be causing the sepsis. Examples would be “sepsis due to UTI” or “pneumonia causing sepsis.” Previously, the connection between sepsis and the infection was assumed. Now, without documentation of the suspected source, sepsis may not be given the full weight it deserves. If the source of sepsis is unknown, it may be useful to mention this fact, but it is not required.
Renal failure redux
As noted in my November 2010 column, dozens of criteria have been proposed and used by physicians for the diagnosis of acute renal failure and its synonymous term “acute kidney injury” (AKI). Recently, though, greater consensus has been reached. The most current and comprehensive recommendations, released in March 2012, are the Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guidelines for Acute Kidney Injury. They suggest any one of the following criteria to substantiate the diagnosis of AKI:
- Increase in serum creatinine by 0.3 mg/dL or more within 48 hours,
- Increase in serum creatinine to 1.5 times baseline, which is known or presumed to have occurred within the prior seven days, or
- Urine volume of less than 0.5 mL/kg/h for six hours or more.
These definitions encompass all causes of AKI: decreased perfusion (including dehydration), intrinsic renal disease, and urinary obstruction. It is essential to use the diagnostic terms “acute renal failure” or “acute kidney injury” since other terminology will result in the assignment of codes that do not reflect the seriousness or significance of the patient's condition.
It is also particularly important to document acute tubular necrosis (ATN) when it is the confirmed or suspected cause of AKI. ATN occurs commonly in hospitalized patients and it is assigned a higher level of severity than otherwise unspecified AKI.
Effective Oct. 1, 2012, malnutrition that is described as mild or moderate will now be classified as a significant comorbidity that contributes to severity of illness classification. This corrects a long-standing coding oversight that considered malnutrition of unspecified severity to be a significant comorbidity, yet it was not significant if documented as mild or moderate malnutrition. As before, severe malnutrition should always be documented when present because it constitutes a very serious condition with much greater severity of illness implications.
A word about uncertainty
For inpatient admissions, diagnoses that are qualified with any degree of uncertainty—using the terms “probable,” “possible,” “likely,” “suspected” or similar terminology—can be coded as if they were confirmed. The caveat is the condition must still be “uncertain” at the time of discharge, rather than confirmed as something else. For this reason, hospitalists should clarify in the record any uncertain conditions that were confirmed and include in the discharge summary conditions that remain “uncertain.”
As with everything else in health care, documentation needs and criteria are constantly evolving. Staying current and incorporating these changes in your practice are crucial to maintaining best practice standards.