After you complete shut in procedure while tripping, there is following information that must be recorded before making any decision on how to kill the well.
Shut-In Casing Pressure (SICP): Read and record the shut-in casing pressure (casing gauge).
In order to get the proper pressure reading, the casing gauge should be installed upstream of the closed choke.
Pit Gain: Read and record the pit gain. Pit volume gained is very critical for the maximum casing pressure calculation.
Practically, while tripping out of hole, a trip tank is used to track displace volume in use. The accurate pit gain value can be easily figure out by finding difference between actual volume taken to fill up wellbore and theoretical fill up volume. However, if the active pits are used to record the displacement volume, it will be very difficult to figure out the accurate pit gain. The concept of determining the pit gain is the same as using the trip tank. However, the reason that I say that it is very difficult to get the accurate pit gain because pit volume is too large to record few changes while tripping.
Time: Record the time that the well control situation is occurred and keep an accurate time log for the entire well kill operation
Bit Depth: Record bit depth.
Reference book: Well Control Books