Intravenous fluids are administered, especially if the blood pressure is low, and antibiotics are commenced. Empirical treatment with broad-spectrum antibiotics is usually necessary until it is known for certain which pathogen is causing the infection, and to which antibiotics it is sensitive. Combinations of penicillins and aminoglycosides are widely used, although ciprofloxacin has been shown to be effective in most cases, and may be preferred to aminoglycosides because of fewer side effects. Metronidazole is often added to specifically treat the anaerobic pathogens, especially in those who are very ill or at risk of anaerobic infections. Antibiotics are continued for 7–10 days. Drugs that increase the blood pressure (vasopressors) may also be required to counter the low blood pressure. Endoscopy
The definitive treatment for cholangitis is relief of the underlying biliary obstruction. This is usually deferred until 24–48 hours after admission, when the patient is stable and has shown some improvement with antibiotics, but may need to happen as an emergency in case of ongoing deterioration despite adequate treatment, or if antibiotics are not effective in reducing the signs of infection (which happens in 15% of cases).Endoscopic retrograde cholangiopancreatography (ERCP) is the most common approach in unblocking the bile duct. This involves endoscopy (passing a fiberoptic tube through the stomach into the duodenum), identification of the ampulla of Vater and insertion of a small tube into the bile duct.
Diagnosis
Blood tests
Routine blood tests show features of acute inflammation (raised white blood cell count and elevated C-reactive protein level), and usually abnormal liver function tests (LFTs). In most cases the LFTs will be consistent with obstruction: raised bilirubin, alkaline phosphatase and γ-glutamyl transpeptidase. In the early stages, however, pressure on the liver cells may be the main feature and the tests will resemble those in hepatitis, with elevations in alanine transaminase and aspartate transaminase.Blood cultures are often performed in people with fever and evidence of acute infection. These yield the bacteria causing the infection in 36% of cases, usually after 24–48 hours of incubation. Bile, too, may be sent for culture during ERCP (see below). The most common bacteria linked to ascending cholangitis are gram-negative bacilli: Escherichia coli (25–50%), Klebsiella (15–20%) and Enterobacter (5–10%). Of the gram-positive cocci, Enterococcus causes 10–20%. Medical imaging
Given that ascending cholangitis usually occurs in the setting of bile duct obstruction, various forms of medical imaging may be employed to identify the site and nature of this obstruction. The first investigation is usually ultrasound, as this is the most easily available. Ultrasound may show dilation of the bile duct and identifies 38% of bile duct stones; it is relatively poor at identifying stones farther down the bile duct. Ultrasound can help distinguish between cholangitis and cholecystitis (inflammation of the gallbladder), which has similar symptoms to cholangitis but appears differently on ultrasound. A better test is magnetic resonance cholangiopancreatography (MRCP), which uses magnetic resonance imaging (MRI); this has a comparable sensitivity to ERCP.