Guest post: Defining “failure”

By Howard Rodenberg, MD, MPH, CCDS

My colleague Dr. Douglas Campbell, my senior partner and mentor in all things CDI, dropped into my glass-fronted office the other day with a question. I mention the glass because, as, Dr. Campbell had the foresight to have his glass wall frosted, while mine remains transparent. This means I can always be found, or it’s obvious when I’m playing hooky. With Dr. Campbell, not so much. A wise man, indeed.

Just as I’m working on institutional clinical definitions on the adult side, he’s doing the same for pediatrics. And he came by one day asking if I knew what “failure” meant clinically. The truth is that I didn’t, for every time I tried to look up a definition for a clinical condition such as acute respiratory failure or heart failure, there were plenty of parameters about what failure looked like—blood gases, ejection fractions, and so on—but no real definition of what failure itself actually meant.

For the answer, we turned to the Internet, that repository of the total knowledge of mankind that is most often used for cat memes. According to Dorland’s Medical Dictionary (2007), failure is “the inability to perform or function properly.” There’s no qualification on it in terms of time or degree. If an organ or system is not working properly, and the compensatory mechanisms are not keeping up, it’s in failure.

This reminded me of a question I saw posted on the ACDIS Forum regarding acute post-operative respiratory failure. In essence, there is a school of thought that someone can’t have acute post-operative respiratory failure unless a certain amount of time (usually 24-48 hours) has passed since surgery and the patient is still on a ventilator.

I tried to track down the origin of the “48-hour” guidance, and the best reference I could find was Coding Clinic, Fourth Quarter, 2011, that states:

“Respiratory failure is a relatively common postoperative complication that often requires mechanical ventilation for more than 48 hours after surgery or reintubation with mechanical ventilation after postoperative extubation.”

There’s nothing in there that says it’s only failure 48 hours after surgery, rather that it may last that long. But the clinical definition of “failure” doesn’t specify any kind of timeframe, and the term “acute” itself implies a new or sudden onset. So, why would you have to wait until 24 or 48 hours to pass before someone can be in a state of “acute failure?”

Clinically, putting a timeframe on “failure” makes little sense. As an emergency physician, it’s been drilled into me that you can get anoxic brain damage if effective oxygenation, ventilation, and circulation is not restored within four minutes of cardiac arrest, and that irreversible cardiac damage occurs after eight minutes have gone by. From this point of view, acute organ or organ system failure begins the moment compensatory mechanisms have become overwhelmed and dysfunction becomes manifest.

I do understand the argument that it’s important to eliminate the effects of other actors before declaring a patient to have organ or organ system failure. This is part of the conundrum with post-operative respiratory failure, as the clinician must wait for the effect of anesthetic gases to pass before establishing an alternate diagnosis. But that timeframe may be shorter than you think. Even if we look at cardiac surgery, where patients were often kept on a ventilator overnight to give them a “rest,” contemporary quality measures suggest that after six hours the effects of anesthesia should dissipate and might represent a “gold standard” time limit for weaning off the ventilator.

It’s also crucial to note that the diagnosis of organ or system failure is based not on mechanisms or pathology, but on the manifestations of dysfunction. I’ll use another ED example here. To a large extent, it doesn’t matter to me as a specialist in emergency care why you have acute heart failure. It might be from a prior infarction, myocarditis, or a valvular abnormality. A specific diagnosis is nice to know, and certainly gives one the intellectual feelies. But what really matters is that I recognize the signs and symptoms and initiate aggressive, lifesaving care. And clinical failure is also independent of what you do. Heart failure may be treated with diuretics, nitroglycerin, or an intra-aortic balloon pump depending upon the exact clinical scenario and local resources. No particular treatment plan, or the lack thereof, invalidates the diagnosis of clinical failure.

The idea that an “acute” condition requires a certain level of care is most problematic in my daily work when looking at the acute respiratory failure. It seems like many times the diagnosis is in question if someone isn’t on high-flow oxygen or a ventilator; and it is often true that nurses reflexively toss some oxygen on anyone with chest pain or respiratory complaints. However, that doesn’t mean that someone on low-flow oxygen, even 2 liters/minute, can’t be in acute respiratory failure. If they normally breathe room air, their room air saturations at presentation < 90-92% (or the only way they keep their saturations up is from hyperventilation), and they manifest signs or symptoms of respiratory distress, that clinically constitutes an organ system failure.

One other caveat in the documentation of “acute” conditions is that by the time someone arrives to perform an admission history and physical, the enterprising ED doc may have already stabilized the acute condition. (Shameless plug for my professional kin.) CDI staff who only look at admission documents often miss the indicators of acuity present on the patient’s arrival which precipitated the need for hospital care, and may wrongly invalidate the clinician’s diagnosis. A review of the ED record, including prehospital care documentation when available, should be a fundamental part of every CDI chart review.

Wait a sec…I hear a tapping noise to my left. I turn my chair and there’s Dr. Campbell again, looking at me though the glass like a toddler views a captive monkey. I’ve got to get that thing frosted.

Editor’s note: Rodenberg is the adult physician advisor for CDI at Baptist Health in Jacksonville, Florida. Contact him at howard.rodenberg@bmcjax.com or follow his personal blog at writingwithscissors.blogspot.com. Advice given is general. Readers should consult professional counsel for specific legal, ethical, clinical, or coding questions. Opinions expressed are that of the author and do not represent HCPro or ACDIS.