If you’ve ever felt fear of being put under anesthesia, you’re not alone. Whether it’s the thought of not waking up or regaining consciousness mid-surgery, there are quite a few nightmare scenarios to entertain. One new film that comes out today plays on yet another frightening notion: Losing your ability to move while remaining conscious.
Don’t Move, a new thriller from Netflix, follows a grieving mother named Iris who, after trusting the wrong stranger, gets injected with an unnamed paralytic agent that will render her fully immobile in 20 minutes, leaving her at this man’s mercy. The film follows her frantic attempt to outrun her captor as the drug debilitates her little by little. At one point, a kind man living in the woods finds her body, and Iris communicates with him through a series of blinks. The result is an anxiety-inducing, bloody chase with a bizarrely life-affirming message.
When it comes to anesthetics, anxieties abound. Even doctors understand this trepidation around paralysis and loss of control. “I think that is one of the things that patients fear the most,” Akshay Bhatt, an anesthesiologist at New York University Langone Health, tells Inverse. “That is something people worry about all the time.”
Perhaps understanding how these drugs work and in what contexts they’re used can assuage some of these fears. And, there are a few things the movie gets wrong about paralytic agents, according to science.
There are four types of anesthesia doctors use during surgeries and procedures: general anesthesia, regional anesthesia, sedation, and local anesthesia. General anesthesia, which usually entails several different medications, puts you out completely, making you lose consciousness and the ability to move (temporarily). These other drugs, Bhatt says, usually include paralytic agents as well as benzodiazepines for anxiety, fentanyl for pain, and propofol for sedation, which also typically causes short-term memory loss. Regional anesthesia blocks sensation to a limb or area of the body, numbing pain. Sedation keeps you conscious but in a state of vague, relaxed awareness. Local anesthesia, administered by cream or needle, numbs pain in a small area of the body, like the gums.
Paralytic agents are one component of general anesthesia. Medically, these drugs are known as neuromuscular blocking agents. They act on the nervous system, disrupting communication between your brain and muscles. Your brain typically sends a signal through your nervous system telling your muscles to move. With this message, the neurotransmitter acetylcholine binds to receptors on muscle fibers, like a lock into a key, to initiate movement. But these paralytics get in the way of this relay.
Bhatt explains there are two kinds of blocking agents: nondepolarizing and depolarizing. Nondepolarizing agents bind to the receptors, preventing acetylcholine from binding to them to deliver the brain’s message for muscles to contract. With all these receptors blocked, your muscles are incapable of receiving the message to move from your brain. Depolarizing agents, however, mimic acetylcholine and, as Bhatt says, overwhelm muscle receptors, leading to one big contraction and relaxation.
These drugs are fast acting, Bhatt says, debunking the film’s first significant plot point. The protagonist has about 20 minutes from injection time until complete muscular shutdown, but Bhatt says these blocking agents can take effect in 90 seconds.
It’s unclear how long Iris remains totally paralyzed, but before long she begins to regain the ability to move piecemeal. However, Bhatt says that depolarizing agents have both a fast onset and offset; without continuous administration, their effects can wear off between 7 and 12 minutes later. So it’s not necessarily realistic that a single injection would paralyze her for potentially hours.
On a darker note, paralytics truly act on all your muscles — including the ones that help you breathe. In the operating room, Bhatt says, “we have to breathe for the patient,” which may involve controlled ventilation or endotracheal intubation. In other words, a fully paralyzed person cannot breathe by themselves, and without assistance will die by either ischemia, which is when the organs don’t receive enough blood flow, or a hypoxic event, which is when the muscles and organs don’t receive enough oxygen. In both cases, it’s horrifying. Iris wouldn’t live through her paralysis, even with the help of the kindly hermit who finds her immobile. She also wouldn’t be able to communicate with him by blinking, nor would she be able to fling her paralyzed body into a hiding spot, even with a burst of adrenaline.
But, rest assured: You’d almost never find yourself in a position at a hospital where a doctor will use a paralytic alone. Bhatt says it’s rare for doctors to give a paralytic on its own without other medication for anxiety, pain, and sedation.
But while Don’t Move isn’t an entirely accurate portrayal of how paralytic agents work, its central fear comes from a real possibility. A sadist certainly could paralyze someone if they wanted to, Bhatt says.
“That would be very mean to do,” he says, before adding, “and a huge legal issue.”
