Knowledge Base

What is Anesthesia and its History

Anesthesia or anaesthesia (from Greek “without sensation”) is a state of controlled, temporary loss of sensation or awareness that is induced for medical purposes. It may include analgesia (relief from or prevention of pain), paralysis(muscle relaxation), amnesia (loss of memory), or unconsciousness. A patient under the effects of anesthetic drugs is referred to as being anesthetized.


Anesthesia is not a new concept. The first attempts at general anesthesia were probably herbal remedies administered in prehistory. Alcohol is one of the oldest known sedatives and it was used in ancient Mesopotamia thousands of years ago. Are you intrigued and want to know more about the history of anesthesia? The Wood Library-Museum of Anesthesiology (WLM) presents an interactive timeline of the history of anesthesia and the profession of anesthesiology.

Pre Operation (Pre-op) – What to Expect

Your surgical experience begins when your surgeon books your upcoming procedure with the hospital. At this point, it is necessary for us to start gathering information about you as our future patient. In order to provide a safe anesthetic and to minimize the chances of last minute cancellations, each patient must be evaluated preoperatively. The preoperative process progresses stepwise:

Hospital Screening: You will be contacted by the hospital for personal information and to answer a brief questionnaire regarding your health

Preoperative Interview:

  • Phone interview- Healthy patients (based on questionnaire) having minor procedures may need only phone interviews with our preoperative screening nurses.
  • In-Person Preoperative assessment- Depending on the complexity of the surgery and your personal health history, you will be screened either by a preoperative nurse or have an in person consultation with an anesthesiologist. Any necessary clearances (medical, pulmonary, cardiac, hematologic, etc.) will be ordered during your anesthetic consultation. Our expert nurses can usually help facilitate obtaining proper consultations quickly in order keep surgical dates. Occasionally, complex medical problems must be medically optimized prior to surgery, making postponement necessary. We do our very best to avoid this.

Preoperative Lab Work: Any lab work requested by your surgeon (blood work, x-rays, EKGs, etc.) can be completed at Hospital during the preoperative interview, or can be sent in by your primary doctor.

Day of Surgery

We understand that surgery can be a daunting experience. Therefore, we try to minimize many of the issues that can lead to anxiety or concern. As part of the pre-operative process, we have a system in place for gathering patient medical histories in advance. This allows our attending anesthesiologists to review your medical history, to acquire any necessary lab work or testing, and to custom tailor an anesthesiology plan for a safer and better outcome.


On the day of surgery, once you have registered you will be brought back to our pre-op holding area. You will be greeted by a pre-op holding nurse, who will measure your vital signs, review your medical history, start an IV (if needed), and give any pre-op medications that were ordered by your surgeon or anesthesiologist.


Later, you will be interviewed by your attending anesthesiologist, who will discuss your medical history and formulate an anesthetic plan with you. This is a great opportunity to ask any questions you might have regarding your anesthesia. Shortly afterwards, you will also be introduced to one of our certified registered nurse anesthetists (CRNAs) who completes Anesthesia Care Team. Our CRNAs along with the attending anesthesiologist are responsible for your well-being while you are in surgery. While you are in surgery, a member of the Anesthesia Care Team will always be present.


Prior to your surgery, your surgeon and the OR nursing staff will also speak with you to answer any last minute questions you might have. After all the medical personnel have spoken with you, a sedative is often given as we proceed into the surgical suite. This sedative often causes an amnestic effect, so you may not remember going to the operating room.


Once your surgery is completed, our team will bring you the Post Anesthesia Care Unit for a recovery period. As your anesthesia begins to wear off, you will be closely monitored for pain and any side effects that develop from your anesthesia. Once you have sufficiently recovered from anesthesia, the recovery room nurses will admit you to the hospital surgical floor or give you discharge instructions and prescriptions for outpatient procedures.

Different Kinds of Anesthesia

There are different types of anesthetics that may be used for your surgery. The decision as to which type of anesthesia that will be used will be dependent upon your personal medical history, the type of surgery you are scheduled for, your surgeon’s preference and your anesthesiologist. With all types of anesthesia, you will be monitored very closely. The anesthesiologist will monitor your breathing and blood oxygen level, heart rate, blood pressure, EKG and temperature. These different kinds of Anesthesia include the following:


  1. General Anesthesia
  2. Regional Anesthesia – Including Epidural, Spinal and Nerve Block Anesthesia
  3. Combined General and Epidural Anesthesia
  4. Monitored Anesthesia Care with Conscious Sedation


The risks and benefits of the various types of anesthetic will be discussed with you by your anesthesiologist prior to your surgery. Please take the time to ask any questions that you might have. Remember, the decision as to the type of anesthesia to be administered is ultimately up to your anesthesiologist. We strive to provide you with the safest anesthetic and best surgical outcome possible.

1. General Anesthesia:
During General Anesthesia, medications are given so patients are unconscious (“asleep”) and unable to feel anypain during the surgical procedure. Some of these medications are given through an IV and others are gases administered through a breathing mask or tube with oxygen. Some of the side effects of general anesthesia include nausea, vomiting, sore throat, muscle aches, shivering and confusion. General anesthesia is the most common type of anesthetic administered.


2. Regional Anesthesiology:
Regional Anesthesiology entails injecting a local anesthetic near nerves to numb a portion of the body. There are several types of regional anesthetics including spinal anesthesia, epidural anesthesia and various specific nerve blocks. When Regional Anesthesia is used, patients may be awake, sedated or put to sleep for their surgical procedure.


Epidural Anesthesia involves the injection of a local anesthetic, usually with a narcotic, into the epidural space, through either a needle or catheter. The epidural space is outside of the spinal cord. This type of anesthesia is commonly used in labor and delivery and for procedures of the lower extremities.


Spinal Anesthesia also involves the injection of a local anesthetic, with or without a narcotic, into the fluid that surrounds the spinal cord. This type of anesthesia is commonly used for genitourinary procedures, cesarean sections and procedures of the lower extremities.


Nerve Blocks are used to block pain at a specific site. By injecting a local anesthetic into or around a specific nerve or group of nerves, pain relief can be localized to the site of pain. This type of anesthesia provides pain control during and after a procedure, It is associated with minimal side effects. Examples of nerve blocks include an adductor canal nerve block for knee surgery, an interscalene nerve block for shoulder surgery, and a supraclavicular nerve block for arm surgery.


3. Combined General with Epidural Anesthesia:
This is a combination technique that puts you to sleep and provides pain control, not only during the procedure, but afterwards as well. The placement of the epidural catheter allows for you to have continued pain relief after surgery, which will help you sleep and to move more comfortably after surgery. This type of anesthesia is commonly used for major abdominal and thoracic (chest) procedures. The epidural catheter may be left in place for several days after your surgery.


4. Monitored Anesthesia Care with Conscious Sedation:
Monitored Anesthesia Care involves the injection of medications through an IV catheter to help you relax, as well as to block pain. A combination of sedative and narcotic medications are used to help you tolerate a procedure that otherwise would be uncomfortable. In addition, the surgeon may inject a local anesthetic at the site of the procedure for pain control. With this type of anesthesia, you are able to respond to questions, but will be drowsy throughout the procedure. Please keep in mind that if for any reason you are unable to tolerate this type of anesthetic, there may be a need for a general anesthetic to be administered to complete the procedure safely.

The Side Effects and Risks of Anesthesia

All operations and all anesthesia have some risks, and they are dependent upon many factors including the type of surgery and the medical condition of the patient. Fortunately, adverse events are very rare.


Your anesthesiologist takes precautions to prevent an accident from occurring. The specific risks of anesthesia vary with the particular procedure and the condition of the patient. Some of the medical conditions which may increase the risks of surgery and anesthesia are obesity, sleep apnea, history of tobacco or drug use, diabetes, high blood pressure, emphysema, heart disease or history of problems with anesthesia in the past.


If you smoke, physician anesthesiologists recommend that you quit. Quitting at least one week before a scheduled surgery is recommended. Patients who smoke have increased risk of wound infections, pneumonia, breathing and heart problems during and after surgery.


If you are overweight or obese, it may be more difficult to place IV’s and breathing tubes. Patients who are obese are at increase risks of wound infections, pneumonia, breathing and heart problems during and after surgery. Weight loss before surgery will reduce your risks associated with anesthesia and your surgical procedure.


Some of the side effects and risks of general anesthesia include nausea, vomiting, sore throat, hoarseness, muscle aches, shivering, and confusion. Major risks of heart or lung problems, awareness, drug reaction, strokes and death are usually very low.

Some of the risks of regional anesthesia may include headache, infection, bleeding, nerve damage, failed block and drug reaction. These risks are also usually very low.

You should ask your anesthesiologist about any risks that may be associated with your anesthesia.


General Guidelines Prior to Surgery

For most procedures it is necessary for you to have an empty stomach, so that the chance of regurgitating any undigested food or liquids is greatly reduced. Some anesthetics suspend your normal reflexes so that your body’s automatic defenses may not be working. For example, your lungs normally are protected from objects, such as undigested food, from entering them. However, this natural protection does not occur while you are anesthetized. So for your safety you may be told to fast (no food or liquids) before surgery. Your doctor will tell you specifically whether you can or cannot eat and drink and for how long.


In addition, the anesthesiologist may instruct you to take certain medications with a little water during your fasting time. For your own safety, it is very important that you follow these instructions carefully about fasting and medications. If you do not, it may be necessary to postpone surgery.


Please be certain that your anesthesiologist is aware of any special dental appliances, caps or partial bridges that you may have. Dentures and contact lenses must be removed prior to surgery and can usually be replaced shortly after your arrival in the recovery room. Please advise your doctor pre-operatively if you have any loose,damaged or diseased teeth.


Although nail polish, make-up and acrylic nails are acceptable, you should be aware that these are not recommended since they may interfere with your anesthesiologist’s ability to optimally observe any changes in your condition during surgery.


All jewelry, including rings, should be removed and left at home. No alcohol should be consumed 24 hours prior or after your surgical experience. Cigarette smoking should be stopped or significantly curtailed one week prior to your operation. In addition, any symptoms of a cold or upper respiratory tract infection should be reported immediately to your surgeon.


Lastly, please be sure to advise your anesthesiologist if you or any blood relatives have any history of Sickle Cell Disease or prior anesthetic difficulties including Malignant Hyperthermia or problems involving muscle relaxants.

Additional Resources

The following are helpful links that can provide additional information about anesthesiology,