The Facts: Paralysis During General Anesthesia

Paralysis During Surgery Explained

Anesthesia and Surgery Image
Anesthesia & Surgery. Photo: © Andrew Olney/Getty Images

You may have heard that you will be paralyzed by medication during surgery, which can be a very scary idea if you are unfamiliar with anesthesia and how the process works.  While it is true that you will be unable to move during your procedure, you will not be conscious for that part of the procedure, so you will be unaware while you are temporarily paralyzed.

Multiple medications are given as part of general anesthesia.

  General anesthesia requires two types of medications to be effective: first, the medications that render you unconscious (asleep) and second, medications that keep you still during surgery (paralytics).  Additional medications are given as needed, such as medications to control blood pressure, fluids or even insulin to control the blood glucose level of a diabetic patient. 

What Causes Paralysis During Surgery?

Medication that causes paralysis, known as paralytics or neuromuscular blocking agents, are typically given through an IV.  These medications are very potent, and work to relax skeletal muscles throughout the procedure.  The most common paralytics, such as vecuronium, rocuronium and succinylcholine, have been used for many years and have been extensively researched for safety.

Why Paralysis Is Necessary During Surgery

The medications that are given to cause paralysis don’t work on every muscle in the body.

  Your heart continues to beat, and your lungs continue to work with assistance from a ventilator, but you are unable to move your body, including your arms and legs, as you normally would.  

This is done for several reasons.  Relaxation of the muscles makes intubation--the insertion of the breathing tube--easier.

  Surgery would be very difficult to perform if the patient were to move during the procedure.  Even the slight movements that individuals make during normal sleep would be very disruptive to the surgery, let alone trying to roll over during the procedure.  

The paralysis medications also makes the lungs more compliant with the ventilator, allowing the ventilator to do more of the work of breathing without resistance from the lungs.  

By forcing the muscles to relax, the muscles are unable to cramp or spasm during a procedure.  A relaxed body, rather than a tensed one, makes surgery easier to perform--tensed muscles can make the work take longer and may require more forceful techniques. 

What About Anesthesia Awareness?

Anesthesia awareness is a very rare event where the patient is paralyzed, but not sedated enough to be unconscious.  Awareness ranges from being slightly aware of what is going on during the procedure with vague recollections of what happened to being wide awake and fully aware of what is happening.


Luckily, most episodes of anesthesia awareness do not happen during the procedure itself when the surgeon is working, but in the minutes between the start of anesthesia when the medications are first taking effect, and in the minutes after the procedure has been completed but the anesthesia has not been completely lifted.  The risks of anesthesia, and how they apply to your individual situation, should be discussed with your anesthesia provider

Side Effects of Paralysis During Surgery

Some muscles wake up from anesthesia more quickly than others.  For most surgeries, medications are given that allow the patient to wake up from anesthesia rather quickly, without ever noticing the effects of paralysis.  When they wake up, they are breathing on their own, able to move and speak, even if they are still groggy.  The intestines can be slow to wake up, which is why patients may be asked repeatedly if they have passed gas in the hours after surgery--passing gas is a sign that the intestine is no longer moving at a sluggish pace. 

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