Propofol: This Is How Joan Rivers Died

Photographed by Jessica Nash.
It's official: Joan Rivers' cause of death has been revealed to be hypoxia (loss of oxygen) induced by propofol, a general anesthetic that was also linked to Michael Jackson's death. Here's what that actually means:
A milky-looking liquid, propofol is a general anesthetic used during surgery (like the one our dearly departed Joan underwent in late August). Local anesthetics are what's used to block pain in a specific part of the body, but when you need to be completely out for a procedure, doctors call for general anesthetics. These are usually delivered through an IV line in your arm before or during surgery. And, an anesthesiologist closely monitors your vital signs throughout the procedure to make sure you're not waking up or drifting too far off.
Unlike morphine, propofol isn't necessarily a painkiller — even though it does block pain. Morphine and other opioid painkillers work by manipulating our opioid receptors, which are responsible for pain signaling. Propofol, on the other hand, acts mostly on our gama-aminobutyric acid (GABA) receptors. As the main inhibitory neurotransmitter in the brain, GABA plays a part in many processes (including sleep patterns). So, it's thought that by increasing the activity of these receptors, propofol induces relaxation, sedation, and that typical "going under" feeling. But, perhaps one of the scariest things about anesthesia is that we aren't completely sure how it works.
Because the entire body is involved, it doesn't come as a huge surprise that the side effects and complications associated with undergoing anesthesia can be varied and grim. But, hypoxia is a known — and very unfortunate — risk of being put under. Because of that inhibitory GABA effect, propofol can be a respiratory system depressant, causing less oxygen to circulate through the body and, eventually, the brain. Also, it's important to note that those who are a little farther along in years can react more sensitively to anesthesia; Joan was 81 when she died.
So, RIP, Joan. We miss you already.