A 44-year-old construction worker comes to the emergency department with nausea and fatigue over the last 2 days. He strained his back at work 7 days ago. He could not move for several days and took over-the-counter painkillers and applied hot packs. The patient still has significant back pain and limited mobility. He smokes 1 pack of cigarettes a day. He drinks alcohol daily and heavily on weekends. In addition, he also admits to using intravenous heroin on occasion.
He was hospitalized for pneumonia 6 months ago and treated with intravenous antibiotics. The echocardiogram during that admission showed normal left ventricular systolic function, mildly dilated right ventricle, and mild pulmonary hypertension.
His temperature is 37.2° C (99° F), blood pressure is 94/50 mm Hg, and pulse is 112/min. There is mild scleral icterus. Several needle tracks are seen on both forearms. No heart murmurs are present. The lungs are clear. There is no abdominal distention. Moderate right upper-quadrant tenderness is present. The spleen is not palpable. There is no peripheral edema.
Laboratory results are as follows:

Which of the following is the most likely cause of this patient's current condition?

Question

A 44-year-old construction worker comes to the emergency department with nausea and fatigue over the last 2 days.  He strained his back at work 7 days ago.  He could not move for several days and took over-the-counter painkillers and applied hot packs.  The patient still has significant back pain and limited mobility.  He smokes 1 pack of cigarettes a day.  He drinks alcohol daily and heavily on weekends.  In addition, he also admits to using intravenous heroin on occasion.
He was hospitalized for pneumonia 6 months ago and treated with intravenous antibiotics.  The echocardiogram during that admission showed normal left ventricular systolic function, mildly dilated right ventricle, and mild pulmonary hypertension.
His temperature is 37.2° C (99° F), blood pressure is 94/50 mm Hg, and pulse is 112/min.  There is mild scleral icterus.  Several needle tracks are seen on both forearms.  No heart murmurs are present.  The lungs are clear.  There is no abdominal distention.  Moderate right upper-quadrant tenderness is present.  The spleen is not palpable.  There is no peripheral edema.
Laboratory results are as follows:

Which of the following is the most likely cause of this patient's current condition?

Quizplus · Accepted Answer

Acetaminophen toxicity should be suspected in any patient presenting with markedly elevated hepatic aminotransferases or acute liver failure. Acetaminophen toxicity has become the most common cause of acute liver failure in the United States and is likely to occur with either a single ingestion > 250 mg/kg or > 12 g within a 24-hour period. Older age, malnutrition, and concurrent intake of medications that induce the cytochrome P450 enzyme (eg, phenytoin or trimethoprim-sulfamethoxazole) are additional risk factors. Chronic alcoholism is also a risk factor. However, acute ingestion of alcohol does not increase the risk and may actually be protective due to its competition with the drug for the same cytochrome P450 enzyme. Unlike most other causes of hepatitis, acetaminophen-associated hepatitis is acute in onset and progresses rapidly. During the first 24 hours of toxicity, patients may be asymptomatic or experience altered mentation or nausea and vomiting. As the condition progresses, patients become more lethargic and, in severe cases, comatose. Patients may develop right upper-quadrant abdominal pain, oliguria, jaundice, and spontaneous bleeding. Elevation of hepatic aminotransferases may not be present until 8-12 hours after ingestion. The level then rises steadily over the course of 3-4 days and often exceeds 10,000 IU/L if not treated with N-acetylcysteine. (Choice A) The ratio of serum aspartate aminotransferase and alanine aminotransferase is usually > 2.0 in alcoholic hepatitis. Serum aminotransferases in alcoholic hepatitis are usually < 300 IU/L and rarely > 500 IU/L. (Choice B) Liver abscess usually presents with fever and right upper-quadrant pain. Transaminases can be mildly elevated but will not number in the thousands. Alkaline phosphatase is usually elevated depending on the size and obstruction the abscess causes. (Choice C) Acute hepatitis C is often asymptomatic and rarely causes hepatic failure. Chronic hepatitis C virus infection is usually slowly progressive and hepatic aminotransferase is rarely > 10 times the normal limit. (Choice E) Severe pulmonary hypertension (right heart failure) can cause passive hepatic congestion, which usually manifests with jaundice. Total bilirubin is generally < 3 mg/dL. Alkaline phosphatase and aminotransferases are only mildly elevated. Educational objective: Patients presenting with markedly elevated hepatic aminotransferases should raise suspicion for acetaminophen toxicity. N-acetylcysteine is the antidote of choice. __________ References: A review of acetaminophen poisoning. (http://www.ncbi.nlm.nih.gov/pubmed/22998987) Acetylcysteine for acetaminophen poisoning. (http://www.ncbi.nlm.nih.gov/pubmed/18635433)

A 44-Year-Old Construction Worker Comes to the Emergency Department with Nausea