A. Each day perform the simple equipment test. Clip the alligator clips together with the leads plugged in, or hold the dome connectors tightly together. Turn on stimulator, increase the current until the light begins to flash. If this happens in sequence the instrument is working properly. If the light does not flash, either the leads are defective or the instrument has malfunctioned.
B. Before administering the neuromuscular blocking drug, one needs to establish the baseline response. If the patient is under general anesthetic but not paralyzed, put the PNS electrodes on, for example, the ulnar nerve location, after good site preparation to ensure complete electrical circuit. Clip on the leads (distal and proximal), turn the unit on and select 10 mA. Use the TW and observe the response. Then increase to 20mA and observe. If the reaction is greater, then increase to 30 mA and so on until there is no change in the response between two settings. Back off to the lower setting and use that as the baseline. If the patient is not sedated, supra-maximal current may also be determined by setting 3 times the current value at which the twitch is first noted on increasing current delivered, from zero.
C. After drug administration, do not change the mA setting on the particular patient. That baseline will allow you to monitor. The stimulator will give you the exact same current every time by varying the voltage to deliver the selected current.
D. The rule of thumb is the following;
4 twitch response = full recovery
3 responses = 70% recovery
2 responses = 50% recovery
1 response = 30% recovery
4 twitch response = full recovery
3 responses = 70% recovery
2 responses = 50% recovery
1 response = 30% recovery
