The doctor ordered a “push” on my sedative, and I succumbed to the sweet blackness.

But then something went wrong, and I was awake too soon, flailing and crying, the medical team scrambling to maneuver the tube that had been placed down my throat in what should have been a straightforward gastroscopy.

I put up a violent struggle on the table: gagging and choking, trying to scream, fighting to pull the medical device out of my esophagus.

“Hold her arms!” I heard someone yell. I felt hot tears, and pure terror … and then more blackness.

This was the third time I had woken up under the twilight anesthesia known as “conscious sedation.”

I soon learned that I am part of only a tiny percentage of people who remember unsettling experiences under conscious sedation. Only three out of every 10,000 people report “undesired awareness” from nongeneral anesthesia, a number only slightly higher than the two out of every 10,000 patients who report this under general anesthesia, according to a study led by Dr. George Mashour, a neuroanesthesiologist at the University of Michigan and one of the world’s experts on anesthesia awareness. While some patients expect, or even want, to be awake during certain procedures, especially colonoscopies, “I don’t think any clinician would want somebody to be terrified or in pain,” Dr. Mashour said.

But it happens.

His research, using the American Society of Anesthesiologists’ Anesthesia Awareness Registry, a voluntary registry of patients with memories under conscious sedation or general anesthesia, showed that 78 percent of those reporting awareness under conscious sedation felt distress, and 40 percent had long-term psychological sequelae, including post-traumatic stress disorder.

Read the full article at the New York Times.