General anesthesia is a combination of inhaled and injected medications resulting in a lack of pain and no memory. This allows physicians and surgeons the opportunity to perform life-saving procedures, such as surgery. The effects of anesthesia are usually immediate and short-lived, meaning that the medication works quickly and clears out of your body within hours.
Central Nervous System
General anesthesia primarily affects the central nervous system. Your central nervous system consists of your brain and spinal cord. According to the University of Maryland Medical Center, general anesthesia shuts down the brain's pain centers so your body doesn't recognize pain. Although physicians have been using different types of anesthesia for decades, they are still discovering exactly how they work. According to physicians at Indiana University, scientists know the cellular pathways triggered when you fall asleep under general anesthesia are not the same pathways your body uses when you wake up. This discovery will lead to better methods of anesthesia and further explains some of the other effects of general anesthesia on your body.
Muscle Relaxation
Doctors at the Hospital for Special Surgery identify one of the muscle groups affected by muscle relaxation during general anesthesia as those which control the gag reflex. Doctors avoid aspiration during surgery using an endotracheal tube and ventilator. Aspiration is the movement of food and stomach acid into the windpipe and lungs. This tube blocks the windpipe from most foreign material but is not fool proof. You will not be allowed to eat or drink for 12 hours prior to surgery in order to reduce your risk. If you violate these guidelines surgery can be postponed or canceled.
Sensation and Memory
General anesthesia causes a lack of sensation or pain response and the inability to form memory during the procedure. According to the University of Maryland Medical Center this is an anticipated response to the medications. When you experience pain the nerves carry the message through the spinal cord and to the brain. The drugs used for general anesthesia shut down the brain's pain-processing center so your body does not recognize pain signals. It also does not lay down any new memory pathways in the brain. This accounts for the amnesiac effect of the medications, even when you are waking up in the recovery room.
Anesthesia Awareness
According to Mayo Clinic there are a very small percentage of people who may awaken unintentionally during surgery. This is called anesthesia awareness. Mayo Clinic estimates this number to be between 1 and 2 people for every 1,000 cases. Most of the time you are only aware of your surroundings but feel no pain but some may experience excruciating pain. Risk factors for anesthesia awareness include past history of heart or lung problems, daily alcohol use or long-term use of opiates, tranquilizers, cocaine or anticonvulsants.
After Effects
According to the Hospital for Special Surgery nausea and vomiting in the recovery room will occur more commonly in children, especially those who are susceptible to motion sickness. Adults who have diabetes, are obese or are pregnant are also more prone to getting sick. Other minor after effects of general anesthesia can include a sore throat, hoarseness, drowsiness, muscle aches or fatigue. Tell your anesthesiologist if you have had this experience in the past so they may modify the medications you receive.
