Anesthesia causes loss of consciousness and blocks pain sensations in the body. Since sneezing is an involuntary reflex triggered by irritation in the nasal cavity, some people wonder if you can still sneeze when under general anesthesia.
It is possible but very rare to sneeze while under general anesthesia. Anesthesia suppresses the neural pathways that trigger sneezing, but sneezes can still occur in some cases due to irritation in the nasal cavity.
Can You Sneeze While Asleep Naturally?
To understand if you can sneeze under anesthesia, it helps to first look at whether people sneeze while asleep naturally. Research shows we typically do not sneeze while in deep non-REM sleep. This is because non-REM sleep suppresses reflexes like sneezing.
However, some sneezes can occur during lighter REM sleep when reflexes are more active. One study monitored sleep sneezing and found nearly 40% of participants sneezed during REM sleep.
Overall, sneezing during natural sleep is uncommon but can happen, especially in REM sleep. Since anesthesia aims to put us in a whole-body sleep-like state, this provides clues that sneezing is also unlikely but possible under anesthesia.
How Anesthesia Affects the Body
General anesthesia induces a controlled, reversible loss of consciousness. This is achieved through administering hypnotic drugs like propofol as well as pain relieving agents.
Anesthesia affects the body in several ways:
- Suppresses activity in the brain areas responsible for awareness and consciousness
- Inhibits reflexes and neural pathways
- Relaxes muscles to prevent movement
- Slows breathing and heart rate
The suppressed neural activity makes it harder for reflexes like sneezing to occur under anesthesia. But because anesthesia does not paralyze all neural activity, some reflex actions can still happen.
Can You Sneeze Under General Anesthesia?
Under general anesthesia for surgery, sneezing is very uncommon but can sometimes still occur.
A few factors play a role in whether sneezing happens under anesthesia:
- Level of anesthesia depth – Deeper anesthesia further suppresses reflexes.
- Irritation in the nasal cavity – Saline solutions, blood, or surgical irritants can trigger sneezing.
- Type of surgery – Head and neck procedures may irritate the nose more.
- Individual differences – Some people have a lower sneezing threshold.
Case reports have documented sneezing occurring during several types of surgeries where these factors are involved:
- Ophthalmologic surgery – from irritation of the nasal mucosa
- Craniotomy – from blood or saline dripping into the nasal cavity
- Neck surgery – from surgical manipulation of the neck area
Even though very rare, these cases illustrate sneezes can still happen under general anesthesia in some situations.
Can You Sneeze Under Local Anesthesia?
Local anesthesia numbs a specific region of the body while leaving the person awake and able to sneeze. Some examples of procedures done under local anesthesia include:
- Dental work
- Minor surgeries
Under local anesthesia, sneezing can easily occur if the nasal cavity gets irritated. The anesthetic only numbs the target area, not the neural pathways that trigger sneezing like general anesthesia does.
In fact, sneezing is more common under local than general anesthesia. A study monitored patients under local anesthesia during nasal procedures and found 33% sneezed due to irritation from surgical instruments.
Why Sneezing Under General Anesthesia Is Dangerous
Though uncommon, sneezing under general anesthesia can present risks including:
- Infection – Sneezing can spread airborne bacteria around the surgical site.
- Tissue damage – The forceful muscular contraction of sneezing can disrupt surgical wounds.
- Foreign body displacement – Sneezing could dislodge implants or materials like bone grafts.
- Bleeding – Increased blood pressure from sneezing can cause bleeding.
These dangers are especially concerning for more delicate surgeries like brain procedures or transplant operations.
That’s why surgeons take precautions to prevent sneezing under general anesthesia when possible. These can include:
- Pre-treating the nasal cavity with medication
- Using throat packs to protect the airway
- Injecting local anesthetic when needed
- Carefully suctioning away irritants
- Administering anti-cholinergic drugs to block neural signals involved in sneezing
Can You Be Woken Up by a Sneeze Under Anesthesia?
It would be very rare for a sneeze alone to wake someone up under general anesthesia. Even if a sneeze occurs, the anesthesia is still suppressing consciousness pathways in the brain.
That said, certain reactions can occur during a sneeze under anesthesia:
- Increased heart rate and blood pressure
- Body movements or contractions
- Coughing or straining
These reflexive responses may prompt the anesthesiologist to adjust the anesthesia dosage. But a single sneeze alone would likely not fully wake someone up.
On the other hand, an external stimulus like surgical pain could trigger both sneezing and arousal from anesthesia. But the sneeze itself would not directly wake the person up.
Case Reports of Sneezing Under Anesthesia
There are a handful of medical case reports documenting patients who sneezed under general anesthesia:
Cranial Surgery Sneeze
A 24-year-old woman underwent craniotomy brain surgery under general anesthesia. During the operation, bright surgical lights were inadvertently shined into her eyes, triggering a sneeze reflex even though she was fully anesthetized.
Neck Surgery Sneezes
A middle-aged man had neck surgery to remove a benign tumor. Several times during the operation, manipulation of his neck tissue caused sneezing under general anesthesia.
Ophthalmologic Surgery Sneezes
A 35-year-old woman had ophthalmologic surgery on her left eye under general anesthesia. However, the anesthesia provider noted three spontaneous sneezes during her operation, likely due to irritation of her nasal mucosa.
Though rare, these cases illustrate sneezes under anesthesia can and do occur in some situations.
Can Anesthesia Affect Your Nose Long-Term?
General anesthesia itself does not cause any long-term damage or changes to the nasal cavity. However, intubation can sometimes lead to nose or sinus issues after surgery.
During intubation, a tube is inserted through the nose or mouth into the windpipe to maintain the airway under general anesthesia. This can occasionally cause some longer lasting side effects:
- Sinusitis from irritation and inflammation
- Nosebleeds from drying and abrasions inside the nasal cavity
- Sense of smell changes if olfactory nerves are damaged
However, these problems are rare and temporary. Any nasal issues after intubation typically resolve within a week or two.
Sneeze Reflex Pathway
To sneeze, a complex reflex pathway must be activated involving the eyes, nose, brain, and nerves:
- Irritation detected in nasal mucosa or eye pupils
- Signal sent via trigeminal nerve to sneeze center in brainstem
- Sneeze center triggers coordinated muscular contraction
- Air expelled forcefully from mouth and nose
Anesthesia suppresses this sneeze reflex arc at multiple levels, but cannot block it completely in some individuals.
Sneeze Reflex Sensitivity
Each person has their own individual sneeze threshold meaning how easily their sneeze reflex is triggered. Those with a more sensitive threshold may be more likely to sneeze under anesthesia from even minor nasal irritation.
Doctors can measure sneeze reflex sensitivity using the following clinical tests:
- Nasal mucosa stimulation – Touches inside the nose with progressively stiffer bristles until sneeze occurs
- Nasal air puffs – Blasts air into the nose until sneezing triggered
- Citric acid provocation – Exposing the nasal cavity to dilute citric acid solution
Those whose sneeze threshold is reached sooner are considered to have higher baseline sneeze reflex sensitivity.
Sneezing under general anesthesia is very rare but can happen in some cases when the nasal cavity gets irritated. Local anesthesia allows for easier sneezing since neural pathways are not suppressed.
Though uncommon, sneezes under anesthesia can potentially disrupt surgery and increase risks. That’s why surgeons take precautions to prevent sneezing when possible.
While an occasional sneeze may occur, anesthesia itself does not damage or permanently alter the nose. And one isolated sneeze is unlikely to wake someone up under general anesthesia.
Ultimately, each person’s sneeze reflex sensitivity varies. But anesthesia strongly suppresses the sneeze pathway to make this involuntary reflex very uncommon during surgery.