What operations requires strict NPO?

I see surgeons order in NPO strict or NPO with meds and ice before surgeries, but there doesn’t seem to any obvious reason why they pick between the two. Some surgeons order NPO strict for laparoscopic cholecystectomy and others will be okay with ice and meds for the same procedure. I’m sure there are surgeries and risk factors that require strict NPO (bariatric, gastroparesis,etc), but is there any resources I can review to determine how this is figured out? Thanks in advance!
Source: Student Doctor Network - Category: Universities & Medical Training Authors: Tags: Surgery and Surgical Subspecialties Source Type: forums