Crystal, I don't have low blood pressure, just normal ranges for me, but I do have severe COPD and am on 02 at night for sleeping and for strenuous exercise.
I just had an upper endoscopy done in December. Not my first, but my first since being on 02. If you prefer to have your endoscopy done w/o sedation (this is the first time I agreed to sedation for endoscopy - all of my previous have been w/o) it is not at all painful. BUT you do gag a lot - and gag hard if the scopist is generous w/the air to inflate the esophagus to ease the passage of the scope. The gagging can bring tears to your eyes even tho there is no discomfort or pain - except the gagging. I have a real strong gag reflex and I didn't do all that much gagging but when I did it curled my toes!
But back to this past December's endoscopy with sedation: you are put on 2L of 02 to start w/which drastically reduces any risks. If you have known lung problems be sure the staff is aware of this before and the day of the procedure. Your BP, pulse, 02 saturation is constantly monitored. This is not general anesthesia you are given but rather conscious sedation, i.e. an amnesiac. It relaxes you, it robs you of your memory but you can respond to the doctor asking you to roll to your side or roll to your back, whatever. It'll make you sleepy. Your throat is sprayed w/something and you are sedated before the scope is introduced into your throat. It really is an easy procedure w/VERY LITTLE risk compared to so many tests we go thru.
If it makes you feel safer insist on your endoscopy being done at a local hospital endoscopy unit where ALL emergency and life sustaining equipment and personnel are immediately available. BUT - really you are monitored thru out the procedure and there is resuscitation equipment on hand to maintain until a stricken patient can be ambulanced to an emergency department.
But really your vital signs are all closely monitored and emergency equipment is on hand as required by law.
Relax and enjoy the "nap". I wish you good results.
Some people are like Slinkies... Not really good for anything, but they still bring a smile to your face when you push them down a flight of stairs.