The epidemiology, prevalence, and classification of hepatic encephalopathy.
Arun B. Jesudian, MD: Elliot, let’s talk a little bit about how big a problem HE [hepatic encephalopathy] is. Can you give us an idea of the epidemiology, the prevalence of HE?
Elliot B. Tapper, MD: This is a good question, and sometimes when we talk about the number of admissions to American hospitals for hepatic encephalopathy, in many ways it kind of understates the problem, in part because our ability to capture these things and administer it into databases can be limited. And, in part, because these patients are among the sickest admitted to any hospital, and are more likely to [experience] adverse events than virtually any other patient. But, in general, there’s about 600,000 to a million people walking around with cirrhosis, maybe cirrhosis portal hypertension. At any given time, about 100,000 people have hepatic encephalopathy. And for a given year, somewhere between 25,000 [and] 40,000 admissions are happening in American hospitals for hepatic encephalopathy. If you take a given cohort of patients with cirrhosis, like we follow from the VA [US Department of Veterans Affairs] or in Medicare, about 28% to 40% will develop hepatic encephalopathy within a few years.
Arun B. Jesudian, MD: Great, thank you. In your opinion, do you think HE is underdiagnosed?
Elliot B. Tapper, MD: I definitely think it’s underdiagnosed. I think it gets back to Dr. Flamm’s comments in that we don’t tend to recognize that someone has a problem with their chronic liver disease until they present with symptoms. But because the symptoms of encephalopathy can appear like delirium in the context of an infection, oftentimes patients are thought to have cognitive impairment or even dementia, unless they’re observed by a specialist or someone with a high index of suspicion for hepatic encephalopathy. I find, particularly in the patients referred to me, that there’s a great delay in the recognition of encephalopathy. To that end, the best tools we have are just [to] spread awareness, perhaps through discussions like this.
Arun B. Jesudian, MD: I do want to talk about diagnosis and classification, how we classify HE. Steve, let me start with you. What type of patients are you evaluating for HE and how do you evaluate them for that?
Steven L. Flamm, MD: It’s a great question, Arun. Hepatic encephalopathy when you have a cirrhotic patient is very common, as Elliot said. And we think about 40% have HE, but one thing he said was important. Within a few years, if you wait long enough, it may be more people have encephalopathy. So this is not an uncommon entity. This is a problem that health-care providers that take care of patients with cirrhosis will see. Now, if you know a patient has cirrhosis already, you should certainly think of hepatic encephalopathy. When they have any mentation issues at all, and we’ll talk a little bit about the diagnosis and the classification in a minute, where it’s trickier is when a patient doesn’t have known cirrhosis. And one of the things I want to mention for the health-care provider audience is what I would consider a pearl, and that is one of the first laboratory signs of cirrhosis in a patient when you don’t even know they have cirrhosis yet: thrombocytopenia. It’s missed all the time. Patients who are otherwise asymptomatic, they have routine labs and the platelet count is 125,000. Occasionally it’s missed and if it’s not missed, the patient is often referred to hematology who does a bone marrow biopsy, finds nothing, and says the patient has ITP [idiopathic thrombocytopenic purpura]. It happens extremely frequently….
Arun B. Jesudian, MD: Many times.
Steven L. Flamm, MD: Many times. It happens all the time. Why do people get thrombocytopenia early? It’s not abnormal liver enzymes, by the way, it’s not jaundice, it’s not INR [international normalized ratio] abnormalities, it’s thrombocytopenia. And I would beckon people in the audience, if they have patients with thrombocytopenia, if they’re primary care physicians or gastroenterologists, look into chronic liver disease even with a normal liver panel. Why do they get it? Because part of portal hypertension early on is patients get splenomegaly. The spleen and the liver are connected, and splenomegaly causes sequestration of platelets and a low platelet count, first up. Now, does everyone with cirrhosis have thrombocytopenia? No, but the majority actually do. So it helps you with the diagnosis of cirrhosis [right] off the bat. And once you know a patient has cirrhosis, then you start to pay closer attention to even subtle changes in mentation because this very frequently represents encephalopathy. And we’re going to talk about the spectrum of encephalopathy in a few minutes. But, if you know a patient has cirrhosis, think about it.