Anesthesia Side Effects

Anesthesia has been used in surgery for more than a century. But while decades of innovation have made it reliably efficient, they have yet to smooth out a few quirks, not least being the numerous side effects. Not everyone will experience adverse symptoms after being put under, but the possibility cannot be brushed aside.

Luckily, most anesthesia side effects are minor. General weakness, headache, and body ache are normal, as the body is still getting used to having sensation back. If a tube was used to administer the drug or to aid in breathing, the patient may have a dry throat upon waking up, which may develop into strep throat later on. The anesthetized area can feel itchy and irritated; doctors usually advise against scratching or tapping and instead prescribe a soothing cream. Major surgeries are commonly followed by jaundice, a condition marked by yellowing of the skin and eyes.

Different age groups can also experience different side effects. In children, shivering and chills are among the most common symptoms. These cannot be prevented, but they can be alleviated by wrapping a thick blanket around the child for a few minutes. In adults, side effects include nausea and vomiting, as well as a range of digestive problems. Many patients report bloody stools and urine the first few days following the operation. Older patients often wake up confused and lose some short-term memory, although this usually passes and is no cause for concern.

Other symptoms are more drastic. For example, a patient’s blood pressure can drop drastically and cause fainting, especially when they first stand up. Rarely, a patient can have an adverse reaction to the anesthesia and require a longer stay at the hospital. This usually happens when a person has an existing condition that wasn’t taken into account. Doctors can also administer too little or too much anesthesia, although such cases are far from the norm.

While many of these side effects can be avoided, most of them actually result from the drug affecting an existing condition. This is why anesthesiologists take a full medical history of the patient, from previous illnesses and surgeries to any known allergies. The latter is especially important because some allergic reactions to anesthesia can be serious. There are different types of anesthesia, and some are made specifically to skirt certain conditions or reactions. The more a doctor knows about his patient, the better the choice he can make.

Epidural Anesthesia

An epidural is a type of regional anesthesia, a drug that numbs a large area of the body. In this case, the numbness extends from the waist down. Its most common use is during normal labor and childbirth, although it is also used for other deliveries such as induced labor, vacuum delivery, and caesarean sections.

Epidural anesthesia is optional; some women choose not to get it for safety or personal reasons. Some doctors recommend using an epidural only in cases of extreme pain or when complications arise that require surgery. In normal deliveries, the pain serves as the signal for the mother to push, so an epidural can actually prolong the process.

The drug is injected into the lower part of the spine, usually with the patient lying on her side and curled up tightly. This gives the anesthesiologist the clearest view of the spinal column possible. The area is first injected with a local anesthetic, which will numb the pain from the actual epidural injection. A test dose is then injected to make sure the epidural is being administered in the right place, then the full shot is delivered through a catheter. Along with the epidural, the patient is given a range of other medications according to her specific needs, delivered through the same catheter.

Epidural injections can be painful, not least because they are usually delivered during contractions and require an uncomfortable position. Some women feel a sharp pain or jerk in their legs during the injection; this means the needle has nudged a nearby nerve, but is no cause for concern.

When the epidural anesthesia is in effect, the patient will feel the contractions but not the pain that would normally come with it. In some women the numbness extends up to the chest or down to the knees. Most patients can discuss the scope of the medication with the anesthesiologist beforehand, choosing how much they want to feel during the birth.

The risks of an epidural are usually minor, such as fetal distress and a drop in blood pressure. Rare complications include nerve injury and paralysis. Also, not all patients can be given an epidural—some conditions make the risks outweigh the benefits. People with heavy bleeding, back infections, low platelet counts, and hard-to-locate spinal features are usually turned down for an epidural. The drug can also react negatively to other medications the patient is taking. If you’re considering an epidural for your birth, make sure to give your doctor your full medical history so any potential reactions can be ruled out.

General Anesthesia

General anesthesia renders a person unconscious during surgery and other major medical procedures. This is both to avoid pain and to block out the memory of the operation. Although being anesthetized is generally called “being asleep,” the patient is actually in a different state. Unlike local and regional anesthesia, which acts on the nerve receptors that receive pain signals from the brain, general anesthesia turns off the brain itself, so that it isn’t able to send any signals at all.

The anesthesia is usually a combination of intravenous drugs and various inhaled gases. Besides these anesthetic agents, the process also involves controlling the patient’s breathing and pulse and monitoring vital functions throughout the surgery.

The risk associated with general anesthesia is low, although side effects are common. These include nausea, digestive problems, fever and chills, numbness, and mild confusion upon waking up. They are usually no cause for worry, especially in healthy patients. The risk rises for people with heart, lung, or kidney problems, people taking aspirin and other blood-thinning agents, smokers, drinkers, and those with allergies or sleep apnea. Obese patients are also at higher risk.
Many people worry that they will wake up while under general anesthesia. This does happen, but it’s very rare—about one in a thousand people—and many are simply aware of their surroundings and don’t wake up in pain. The likelihood is higher during emergency surgery (where often a different type of anesthesia, called dissociative, is used) and in patients who drink alcohol daily, have heart or lung conditions, and have been using tranquilizers or anticonvulsants.

Patients are asked to fast several hours before being put under because the procedure turns off the body’s ability to retain food in the stomach, which means any food taken may end up in the lungs. Some medications may also be stopped during this period; these include oral diabetes treatments, which can interfere with blood function.
The anesthesiologist and his team will take a full medical history of the patient before the operation. This will allow them to choose the right mix of drugs (some people can have adverse reactions to common anesthetic agents, or may be allergic) and avoid complications. If the patient has undergone surgery before, the team will also look into prior anesthesia used as an indicator. This is why it’s important to tell the doctors everything—the more information they have, the safer and more effective the medication will be.


We are going to focus on the three aspects which, to our understanding, are most appealing. Please remember to read the clarifications made under the “Legal Warning” section at the end of the article.


Anaesthesiology is the field of Medicine which deals with pain treatment and integral care of the surgical patient before, during and after surgery.

Apart from the above-mentioned fields of action, our speciality currently includes others, namely pain treatment, critical medical profiles and extrahospital or intrahospital emergencies.

Our duties inside the operating theatre go beyond anaesthetizing patients, mainly consisting of protecting and regulating their vital signs, in order for the surgical intervention to cause them the least possible alterations.

In fact it is us, the surgeons, who are in charge of diagnosing and tackling any problem or medical incident which may occur while practising the operation or during the postoperative period immediately after.

The main types of anaesthetics are:

General anaesthetics: The patient remains unconscious.

Regional anaesthetics: The region of the body which is going to be operated on is anaesthetized, hence its name. To do so, the anaesthetic is injected into the region close to the nerves which capture the sensitivity of that region.

Local anaesthetics: Anaesthetics is directly administered into the area on which the surgeon is going to operate.

Anaesthetics always entails a risk for the patient, which will vary mainly according to the type of intervention which the patient is to undergo and their physical health prior to the operation.

Anyhow, serious accidents are exceptional. Complications related to anaesthetics have significantly decreased in the past 25 years. Likewise the number of deaths attributed to anaesthetics has fallen dramatically. Today it is estimated that the death risk due to anaesthetics is 1 out of 200,000 cases.


Epidural analgesics is administered into the spine or vertebral column between two vertebrae of the lower part of the back. A special needle is used which enables us to identify the epidural space, located just outside the meninges, which contain the cephalorachideal liquid and the spinal chord.

In most cases, its duration can be extended for the time required.

In general it is safe both for the mother and the newborn, but can occasionally cause complications and side effects which are rarely serious. Such complications may arise despite the patient being carefully observed and the anaesthesiologist having taken all the necessary precautions to prevent them.


Many of the techniques and medicines anaesthesiologists use to alleviate pain during surgery can also be used for other types of pain. We know this thanks to the inclusion of the study of different forms of acute and chronic pain as well as their treatment in our medical training.

Pain Treatment Units are normally made up of and managed by anaesthesiologists who have specialized in this practice.

However, a Pain Clinic normally consists of multidisciplinary units where other specialists, usually consultants specialized in Internal Medicine, Oncology, Rheumatology, Rehabilitation and Psychology, also carry out their healing tasks. They are all backed by the experience and the knowledge required to asses which treatment suits each patient.



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