QuestionSBA
QuestionChoice
A 'confusion screen' - i.e. blood tests measuring B12, folate, ferritin, and potentially a head CT, are important investigations in patients presenting with altered mental status. However, the most important diagnosis to exclude in this case is SBP, so abdominal paracentesis is the next most appropriate investigation.
10028233
c
Confusion screen
QuestionChoice
The combination of a fever and altered GCS do raise suspicions for meningitis, however the patient is encephalopathic (as evidenced by asterixis) and there are no features of meningism mentioned. The most likely source of infection is spontaneous bacterial peritonitis, which must be investigated for using a diagnostic paracentesis.
10028234
d
Lumbar puncture
QuestionChoice
Ammonia has very limited utility in liver disease. This patient is clinically encephalopathic, so measuring the ammonia does not add any additional information.
10028232
b
Serum ammonia level
QuestionChoice
Any patient presenting with ascites in hospital should have this 'tapped' to check for spontaneous bacterial peritonitis, which has an extremely high mortality rate. The degree of suspicion for SBP in this case is increased by the fact the patient is febrile and has a tender abdomen. A white cell count of >250 with 90% neutrophils would confirm the diagnosis.
10028231
a
Diagnostic paracentesis
QuestionChoice
This will add limited information in the acute setting. Once the patient is stable, an ultrasound may help assess the liver and volume of ascites, however it is not the next most appropriate investigation.
10028235
e
Ultrasound abdomen
Concept
Chapter
2693
4343
Liver Cirrhosis
Topic
136
Gastroenterology
18044
Spontaneous bacterial peritonitis (SBP) is a bacterial infection of the ascitic fluid in patients with liver disease, and diagnostic paracentesis is performed to analyze the fluid for elevated white blood cell count and the presence of bacteria, confirming the diagnosis and guiding treatment.
A 57-year-old man with a diagnosis of cirrhosis due to alcoholic liver disease is brought to ED by his wife, who is concerned that he is more confused than normal. He has been drinking 8 cans of beer a day for the past 7 years.

On examination, he has multiple spider naevi and asterixis is present. His abdomen is tense, distended and tender.

Observations:

* Heart rate: 98 beats/minute
* Blood pressure: 97/68 mmHg
* Respiratory rate: 18 breaths/minute
* Temperature: 38.2 degrees
* Oxygen saturations (room air): 96%
* GCS: 13/15

What is the most important investigation to perform?
a