Assess the actual liver function capacity of your patients at the bedside and in real-time
Conventional measurements of liver enzymes or proteins in blood as well as ultrasound scans, only provide indirect, retrospective information about the status of the liver.
The LiMAx test – liver maximum capacity test – is the only test that can precisely determine the actual liver function capacity. Together with a LiMAx algorithm2, rapid and accurate readouts of liver function capacity support surgical planning, allow selection of appropriate patients for liver resection, and enable a liver capacity-based fast track protocol for the postoperative management of the patient. All of these have potential to improve treatment and overall outcomes of patients.
The principle behind LiMAx®
LiMAx is a real-time breath test based on measuring the activity of CYP1A2, a member of the cytochrome P450 superfamily of enzymes. CYP1A2 is distributed throughout the entire liver acinus and exclusively expressed in hepatocytes throughout functional liver tissue. It is not expressed as frequently in diseased liver tissue, and therefore its overall activity levels can be used as a marker for quantifying liver function capacity.
The LiMAx test involves the patient receiving a non-radioactive and isotope-labeled drug, 13C methacetin. This is metabolized in the liver only by CYP1A2 into 13CO2, which is exhaled, and paracetamol (figure 1).
When the patient breathes into the LiMAx test mask, the ultra-sensitive laser system in the FLIP® detection device continuously measures the amount of 13CO2, which is proportional to the patient’s liver capacity.
FLIP is able to detect continuously extremely low concentration in every breath. Because it is mobile, the FLIP device can be used in intensive care units, emergency rooms, and outpatient stations.
In figure 2 you see the test principle of the LiMAx test.
LiMAx®Value: the test results
The results from the LiMAx test can be used to stratify the patient’s liver function capacity into three different levels of impairment (figure 3).
1 Stockmann M et al., Prediction of postoperative outcome after hepatectomy with a new bedside test for maximal liver function capacity, Annals of surgery 250.1 (2009):119-125.
2 Stockmann M et al., The LiMAx test: a new liver function test for predicting postoperative outcome in liver surgery, Hpb 12.2 (2010):139-146.