Instruct: Classify Amazon reviews into positive or negative sentiment
Query: A trip to the emergency room.

I was opening a blister packed product this weekend, and found, like some other users, that the guarded blade didn't work well enough to open the plastic packaging. I was using the retractable blade to open the package, and the blade slipped and cut my leg. Unfortunately, this nicked a surface artery, requiring a trip to the emergency room and three stitches.