Gastrointestinal Clinical Case / MCQS / Uworld for
Usmle step 2 and IFOM / case 7 with
answer and explanation and references and Educational objective
A
20-year-old college student Is brought to the emergency department after his
friend found that he Ingested large amounts of acetaminophen in a suicide
attempt. The patient has been depressed since his girlfriend broke up with him
a week ago, and he took approximately 30 pills of 500-mg acetaminophen 2 days
ago to end his life. He has nausea and mild abdominal pain. His temperature is
36.7 C (98 F), blood pressure is 114/68 mm Hg, and pulse Is 94/min. Abdominal
examination shows mild tender hepatomegaly. Serum acetaminophen level is high,
and the patient is hospitalized for N-acetylcysteine therapy. During the
hospital stay, he becomes markedly confused and incoherent. Repeat examination
shows scleral icterus and asterixis. Current laboratory results and those
obtained at the time of admission are as follows:
Liver
function studies
Total
bilirubin 4.1mg/dL (1.2 mg/dL )
Aspartate
aminotransferase 8456 U/L (96 U/L)
Alanine
aminotransferase 9634 U/L (70 U/L)
Prothrombin
time 120 sec (18 sec )
Serum
creatinine 3.5
mg/dL (1.1 mg/dL )
Which of
the following Is the best next step in management of this patient?
A.
Close monitoring only .
B.
Discontinue N-acetylcysteine .
C.
Initiate vitamin K supplementation .
D.
Perform liver biopsy .
E.
Refer to liver transplant center .
F.
Start glucocorticoid .
Answer :
E
Explanation:
This
patient has acute liver failure (ALF) due to acetaminophen toxicity. ALF is defined
as severe acute liver Injury without underlying liver disease and is
characterized by elevated aminotransferases (often >1000 U/L), hepatic
encephalopathy (HE), and synthetic liver dysfunction (defined as prolonged prothrombin
time (PT) with INR ≥1.5). Approximately only half of patients with ALF will
survive without liver transplantation (LT). Reliable Indicators of worsening
ALF include rising serum bilirubin and PT. as seen in this patient. Acute renal
insufficiency, likely due to decreased renal perfusion, is common and portends
a lower chance of recovery without LT. The degree of HE is also of prognostic
importance as grade Ill HE (characterized by marked confusion and Incoherence,
as seen In this patient) is associated with only a 40%-50% chance of
spontaneous recovery. Cerebral edema is a potential complication of ALF that
may lead to coma and brain stem herniation, and is the most common cause of
death.
In ALF
due to acetaminophen toxicity, L T is firmly indicated in patients with grade
Ill or IV HE, PT >1 00 seconds, and serum creatinine >3.4 mg/dl (such as
this patient). One-year survival following L T for ALF Is approximately 80%.
(Choices
A and D ) Liver biopsy Is sometimes helpful in ALF of unclear etiology. This patient's
ALF Is due to acetaminophen toxicity and his condition is worsening. Close monitoring
alone would not be appropriate, and liver biopsy is unlikely to prevent the need for
LT.
(Choice
B) When administered within 8 hours of acetaminophen ingestion, N-acetylcysteine
markedly improves the rate of recovery in acetaminophen overdose and may be
beneficial in other etiologies of ALF. This patient, who presented 2 days after
acetaminophen Ingestion, may obtain some benefit from N-acetylcysteine and
should continue therapy while undergoing evaluation for LT.
(Choice
C) This patient's prolonged PT reflects coagulopathy due to ALF rather than to vitamin
K deficiency (which would be seen in patients with malnutrition). As a result, vitamin
K supplementation has limited efficacy as it would not address the underlying cause.
(Choice
F) Glucocorticoids are generally not indicated in ALF as they increase the risk
of infection and have not demonstrated benefit in most etiologies of ALF. They
may provide benefit In alcoholic hepatitis and in ALF due to autoimmune
hepatitis.
Educational
objective:
Liver
transplantation should be considered in all patients with acute liver failure
and indications that the disease Is worsening or failing to improve.
You can see another Gastrointestinal Clinical Cases / MCQS / Uworld for Usmle step 2 and IFOM /
with answer and explanation and references and Educational objective
A 20-year-old college student Is brought to the emergency department after his friend found that he Ingested large amounts of acetaminophen in a suicide attempt. The patient has been depressed since his girlfriend broke up with him a week ago, and he took approximately 30 pills of 500-mg acetaminophen 2 days ago to end his life. He has nausea and mild abdominal pain. His temperature is 36.7 C (98 F), blood pressure is 114/68 mm Hg, and pulse Is 94/min. Abdominal examination shows mild tender hepatomegaly. Serum acetaminophen level is high, and the patient is hospitalized for N-acetylcysteine therapy. During the hospital stay, he becomes markedly confused and incoherent. Repeat examination shows scleral icterus and asterixis. Current laboratory results and those obtained at the time of admission are as follows:
Liver
function studies
Total
bilirubin 4.1mg/dL (1.2 mg/dL )
Aspartate
aminotransferase 8456 U/L (96 U/L)
Alanine
aminotransferase 9634 U/L (70 U/L)
Prothrombin
time 120 sec (18 sec )
Serum
creatinine 3.5
mg/dL (1.1 mg/dL )
Which of
the following Is the best next step in management of this patient?
|
A.
Close monitoring only . B.
Discontinue N-acetylcysteine . C.
Initiate vitamin K supplementation . D.
Perform liver biopsy . E.
Refer to liver transplant center . F.
Start glucocorticoid . |
Answer :
E
Explanation:
This patient has acute liver failure (ALF) due to acetaminophen toxicity. ALF is defined as severe acute liver Injury without underlying liver disease and is characterized by elevated aminotransferases (often >1000 U/L), hepatic encephalopathy (HE), and synthetic liver dysfunction (defined as prolonged prothrombin time (PT) with INR ≥1.5). Approximately only half of patients with ALF will survive without liver transplantation (LT). Reliable Indicators of worsening ALF include rising serum bilirubin and PT. as seen in this patient. Acute renal insufficiency, likely due to decreased renal perfusion, is common and portends a lower chance of recovery without LT. The degree of HE is also of prognostic importance as grade Ill HE (characterized by marked confusion and Incoherence, as seen In this patient) is associated with only a 40%-50% chance of spontaneous recovery. Cerebral edema is a potential complication of ALF that may lead to coma and brain stem herniation, and is the most common cause of death.
In ALF due to acetaminophen toxicity, L T is firmly indicated in patients with grade Ill or IV HE, PT >1 00 seconds, and serum creatinine >3.4 mg/dl (such as this patient). One-year survival following L T for ALF Is approximately 80%.
(Choices A and D ) Liver biopsy Is sometimes helpful in ALF of unclear etiology. This patient's ALF Is due to acetaminophen toxicity and his condition is worsening. Close monitoring alone would not be appropriate, and liver biopsy is unlikely to prevent the need for LT.
(Choice B) When administered within 8 hours of acetaminophen ingestion, N-acetylcysteine markedly improves the rate of recovery in acetaminophen overdose and may be beneficial in other etiologies of ALF. This patient, who presented 2 days after acetaminophen Ingestion, may obtain some benefit from N-acetylcysteine and should continue therapy while undergoing evaluation for LT.
(Choice C) This patient's prolonged PT reflects coagulopathy due to ALF rather than to vitamin K deficiency (which would be seen in patients with malnutrition). As a result, vitamin K supplementation has limited efficacy as it would not address the underlying cause.
(Choice F) Glucocorticoids are generally not indicated in ALF as they increase the risk of infection and have not demonstrated benefit in most etiologies of ALF. They may provide benefit In alcoholic hepatitis and in ALF due to autoimmune hepatitis.
Educational objective:
Liver
transplantation should be considered in all patients with acute liver failure
and indications that the disease Is worsening or failing to improve.
You can see another Gastrointestinal Clinical Cases / MCQS / Uworld for Usmle step 2 and IFOM /
with answer and explanation and references and Educational objective
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