General Anesthesia Side Effects
Of all the types of anesthesia, general anesthesia is used most often for surgery. Common anesthesia side effects are annoying but cause no lasting harm. A complication, on the other hand, can be seen as an outcome that is undesirable and causes harm to the patient. Complications are sometimes avoidable and sometimes unavoidable, depending on the pre-existing conditions of the patient and other factors.
So again, a side effect is an outcome that accompanies the desired effect of a medication or treatment that causes annoyance or discomfort, but no lasting harm to the patient.
General anesthesia involves the use of IV and inhaled medicines to induce and maintain an unconscious state. Because these medications affect how your body works, it is not surprising that they are associated with side effects, and less commonly, complications. Given the significant changes induced by these potent, but necessary, medications, the safety record of general anesthesia is particularly impressive.
Side effects though, often cannot be avoided with general anesthesia and most people experience one or more of the most common anesthesia side effects.
A scratchy, sore throat commonly occurs after general anesthesia. When you are “asleep” with general anesthesia, you are actually unconscious. Sometimes, you are able to breathe adequately on your own in this state, and sometimes your breathing needs to be assisted or controlled. Some surgeries, particularly those in the abdomen or chest require your muscles, including your breathing muscles to be relaxed.
In order to help you breathe or control breathing, the anesthesiologist can choose among several methods.
Most commonly, for abdominal, chest, brain or other major surgery, a breathing tube will be used. Thisendotracheal tube as we call it, is placed into the windpipe by sliding it between the vocal cords after you are unconscious. While this is usually an easy, gentle procedure, the back of the throat and the windpipe are super sensitive areas. Most people will have a sore throat from the breathing tube. It usually lasts a day or two, can be relieved with lozenges and ice water and then resolves on its own.
If a breathing tube is not used, another device called a “laryngeal mask airway” — LMA — can be used. This is a soft rubber mask that is made to fit inside the back of the throat. There is an opening for oxygen to pass through which sits over top of the inlet to the windpipe. The LMA allows you to breathe on your own and can be used for surgeries on the arms or legs or outside of the body cavities. The LMA may be associated with less incidence of, or lower severity of sore throat, but sore throats still occur pretty commonly with an LMA.
(Side Note: Although an LMA sounds more desirable, there are some factors which make an LMA less advisable, like acid reflux. Since the windpipe isn’t blocked off from the esophagus, or food tube, like it is with a breathing tube, acid could potentially enter the lungs if you have this condition. Obesity makes it more difficult to deliver enough oxygen to a heavy chest and abdomen, especially under the influence of the anesthesia drugs. So if your anesthesiologist has to use a breathing tube there is usually a surgical or patient factor helping to guide that decision)
Regardless of the breathing device used, oxygen and anesthesia gases, although often humidified in the operating room, still dry out the mucosa of the throat contributing to that sore, scratchy feeling.
NAUSEA AND VOMITING
A most feared side effect of general anesthesia is nausea, often accompanied by vomiting. Some people (this anesthesiologist included) are VERY prone to postoperative nausea and vomiting — PONV. The mechanism of triggering nausea and vomiting almost certainly involves anesthesia’s effect on brain centers and interaction with the gastrointestinal system.
PATIENT RISK FACTORS FOR POST-OPERATIVE NAUSEA AND VOMITING (PONV)
- Female gender
- Younger age
- History of motion sickness
- History of previous PONV, or family history of PONV
SURGICAL RISK FACTORS: Surgeries more likely to lead to PONV
- Any surgery lasting longer than 30 minutes
- Abdominal and gynecologic
- Ear, nose and throat
- Laparoscopic surgeries
- Breast surgery
- Eye surgery
- Some orthopedic surgery
By looking at this list, it seems almost all surgeries are included. In addition, there are anesthesia factors such as use of narcotic and gas medications, which are often unavoidable.
So if we can’t change many of these risk factors what can we do about PONV?
PREVENTION OF POSTOPERATIVE NAUSEA AND VOMITING (PONV):
Patients– Follow preop instructions about not eating and tell your anesthesiologist or the preop nurse about your risk factors (they will probably ask anyway). Some people say they have been helped by the accupressure relief bands that are sold over the counter. Bring one with you and ask that it be applied as soon as it is safe (usually after surgery, but sometimes before). When you get home, even if you feel hungry, start slowly with eating – start with soft, easy to digest foods. Eat little bits at a time and wait to see how you feel before moving on to harder to digest meals. Some people prefer to stay on liquid diets for the first day after anesthesia, and if you have had abdominal or gastrointestinal surgery, your diet will be restricted as ordered by your surgeon and advanced at their discretion. Ginger is often recommended as another over-the-counter nausea reliever. Follow your postop instructions, as well.
Anesthesiologists– We can give prophylactic (preventative) medications to help reduce the risk of PONV. There are various drugs we can give alone or in combination, based on the level of risk and the risk/benefit ratio of each drug, because, yes, they have side effects too. Sometimes, we can alter the type of anesthetic or the medications used if the risk is significant. We also try to make sure you are properly hydrated, especially if you have gone a long period of time before your surgery without liquids.
Surgeons– Surgeons need to get the surgery done and cannot make significant alterations in procedure to avoid nausea and vomiting. Surgeons can, at your request, prescribe an anti-nausea medicine along with the pain medicine that you will be taking. If you are prone to nausea and vomiting from the anesthetic, there is a good chance that the narcotic pain meds will make you sick, as well. So ask your surgeon in preop (before you are too out of it to remember) to prescribe the anti-nausea medicine.
Most people are confused in the recovery room as a result of the medications. It takes a while for the brain to actually wake up, even after you are conscious. Most people don’t remember much after the preop sedative has been given.
But some people remain confused for days or weeks, or longer after their surgery and anesthetic. This is an active field of study right now, called POSTOPERATIVE COGNITIVE DYSFUNCTION (POCD). It’s interesting to note, though, that this doesn’t just occur with general anesthesia. Surprisingly, to anesthesiologists and researchers, even patients who had other types of anesthesia that should not affect the brain profoundly have had POCD. It seems that other factors, such as the stresses of surgery and recovery on the body may also play a role.
We only know at this point that older patients and patients of lower socio-economic status have a higher risk for POCD. Active and diligent research continues to try to pinpoint who is at risk, why this occurs and what, if anything, can be done to prevent it.
If you have a sore throat after anesthesia and you also get the side effect of muscle aches, you may be concerned that you are getting the flu or that you “caught” something in the hospital. The combination can truly make you feel that way. But muscle aches are another relatively common side effect.
Muscle aches result, in some people, from one of the medicines used to relax or “paralyze” the muscles to make it easier to insert the breathing tube and to perform the surgery. Succinylcholine causes the muscles to “fasiculate” or rapidly contract and relax. This action may make the muscles feel sore for a day or two after surgery.
Heating pads and tylenol can be used for symptom relief, if anything at all is needed. Ask your surgeon before taking medicines like aspirin or ibuprofen as these can contribute to bleeding from recent surgical sites.
Muscle and joint soreness can also result from lying motionless on the operating bed for extended periods of time. Unlike normal sleep, your body can’t even make minor adjustments in position while you are under anesthesia. If you have pre-existing problems with a sore or stiff are on your body, tell your nurse and anesthesiologist. If it doesn’t interfere with the surgery, they may be able to pad or support that area differently to try to help.
A curious side effect of narcotic pain medication (often used as part of the anesthetic) is itching. Most people complain of itching on their face, especially the tip of the nose. Sometimes, people will have significant, all-over body itching and believe they are having an allergic reaction (and it can be hard to tell the difference), but most of the time, it’s just a side-effect.
Luckily, diphenhydramine (Benedryl) can treat this side effect. Make sure it’s ok to take over-the-counter agents with the prescriptions you have been give. If you are still in the hospital, special medicines that block the receptor responsible for the itching but not pain relief can be used and are even more effective.
Narcotics are routinely used during anesthetics to block pain receptors and often cannot be avoided. Tell you anesthesia provider if you have had this bothersome side effect in the past.
A rather curious and common, although less researched, side effect of anesthesia seems to be emotional displays or outbursts upon awakening. It should be stressed that in no way are these displays of emotion under voluntary control of the patient and if you have one of these extreme emotional reactions, it will not be held against you in any way. We know it’s the meds.
A young man may wake up combative and in “fight” mode. Very often, their occupation or background gives clues that this may be an issue. In certain people, I have extra medication ready to calm an overly aggressive emergence from anesthesia. This combative, agitated awakening is seen more often in soldiers, marines and other military personnel, those who work in law enforcement and those who have been or are in jail or gangs. Luckily, this usually resolves in less than 5 minutes and as they wake up are able to be ‘reoriented’ to where they are and settle down on their own. Even when someone is very agitated, I probably give a little sedative less than 10% of the time and only if I feel the patient may hurt himself or someone else (I got thumped in the sternum pretty hard once, so have the medication ready, just in case).
Young women usually are at the other end of the spectrum. Females from about puberty on, seem more likely to wake up tearful and crying. When they are awake enough to talk, they cannot explain why they are crying and don’t say they feel particularly sad most of the time. They just can’t stop crying. This usually lasts less than 15 or 30 minutes.