NGT: Nasogastric Tube
LIS: Laboratory Information System
Therefore, "NGT to LIS" means "transferring a sample from a Nasogastric Tube to a Laboratory Information System."
This usually implies that a sample taken from a patient's stomach through a nasogastric tube is being sent to the lab for analysis. The Laboratory Information System will store and manage the sample information, including the patient's details, the reason for the test, and the results.
However, without context, it's impossible to be 100% sure. It's always best to clarify with the medical professional who used the abbreviation to confirm its meaning.