Purpose of review: This is a review on the techniques for assessing liver function in critically ill patients.
Recent findings: Actually, there is no ideal real-time and bedside technique for assessing liver function in critically ill patients. Though not allowing to differentiate between liver blood flow and cell function, dynamic tests, that is indocyanine green plasma disappearance rate and lidocaine metabolism (monoethylglycinxylidide test), are superior, however, to static tests. Recently, the indocyanine green plasma disappearance rate, which nowadays can be measured reliably by a transcutaneous system in critically ill patients, was confirmed to correlate well with indocyanine green clearance. In general, the indocyanine green plasma disappearance rate is superior to bilirubin, which is still used as a marker of liver function, and comparable or even superior to complex intensive care scoring systems in terms of outcome prediction. Furthermore, indocyanine green plasma disappearance rate is more sensitive than serum enzyme tests for assessing liver dysfunction and early improvement in the indocyanine green plasma disappearance rate after onset of septic shock is associated with better outcome.
Summary: Since no ideal tool is currently available, dynamic tests such as indocyanine green plasma disappearance rate and monoethylglycinxylidide test may be recommended for assessing liver function in critically ill patients. The indocyanine green plasma disappearance rate has the advantage, however, of being measurable noninvasively at the bedside and providing results within a few minutes.