Anaesthesia Basics:
Anesthesia is a medicine given to relieve pain and to create numbness or a state of unconsciousness during surgery.
Types of Anaesthesia: Three main types of anesthesia are local, regional, and general.
Local anesthesia numbs the part of your body where one has the surgery. It is for simple procedures such as sewing up a cut or removing a skin growth or nail.
Regional anesthesia numbs a larger segment of the body. Regional anesthesia can be used for more time taking or elaborate procedures than those that can be performed under local anesthesia. Various types of regional anesthesia are:
- For spinal anesthesia, you are given the anesthetic with a needle in your spine. The drug takes effect quickly and blocks pain in the lower body. It may be used for many operations below the navel, such as rectal, bladder, and prostate operations, as well as operations on the legs.
- Epidural anesthesia may be used for many of the same procedures for which spinal anesthesia is used. It is also given with a needle in the back. The dose is adjusted so that the nerves that transmit pain are blocked, but you keep the ability to move. In some cases a thin tube, or catheter, may be placed at the site of injection to treat pain for several days after surgery.
- Axillary Block: In a way similar to spinal anaesthesia, here the drug is given in the Brachial plexus present near your axilla/shoulder. It acts by creating effect in the desired arm/forearm. It is used for many orthopaedic procedures.
- Biers block: In this anaesthesia the anaesthetic drug is restrained in a particular limb by preventing its absortion in systemic circulation through the use of a tourniquet.
General anesthesia relaxes your muscles, puts you to sleep, and prevents one from feeling pain. It may be given as a drug intravenously (IV) or as a gas inhaled through a breathing mask or tube. While in most of the regional or local anaesthesia, you are awrae of the proceedings in the operating room to a varying degree, in general anaesthesia you are completely in an unconscious state.
Pre Anaesthetic Procedure:
It is a common practice to get a detailed work up including different blood test, chest X ray and if you are above forty years of age an ECG done before you will be subjected to anaesthesia. This is done to ensure that you are fit for the procedure and anticipate any especial things that may be required during the aneathesia. Preparation for anesthesia varies depending on the kind of surgery that has been planned for you. You will be given a detailed instruction on what to stop eating or drinking. You may be administered some medication to relax you and decrease your respiratory secretions. It is important to inform your attending doctor or nurse about any allergy that you may be suffering from. If you are scheduled for a major surgery, an anaesthetist may come to perform a pre anaesthetic check up on you. You may also be given an option of deciding the type of anaesthesia you may prefer for the surgery.
Anaesthesia Administration:
Local anesthesia is usually given by injecting a specific part of your body with a drug that numbs the nerves. It may be required to give several injections to ensure that the entire area is anaesthetized. In certain cases some local anaesthetic patches are also applied to make that particular area numb.
Spinal anesthetic is injected through a small needle into the fluid-filled space surrounding your spinal cord. Epidural anesthetic is injected just outside the sac that contains your spinal fluid known as epidural space. Usually a catheter is placed in the space to inject the medications. This may be left for a few days to reduce the postoperative pain.
You may be given a sedative with a local or regional anesthetic to relax you and reduce anxiety. The sedative may cause you to fall asleep during the surgery. You may at certain centres choose to listen to music if you want while during anesthesia.
If you are having general anesthesia, drugs may be given by injection into a vein. If gas is used, it is given through a mask covering your nose and mouth, or through a breathing tube in your throat. In some cases a muscle relaxant is given in addition to the anesthesia. While you are asleep you will have a breathing Endotracheal tube placed through your mouth and into your throat. The tube will be removed before you wake up after the surgery. It allows the anesthetist to help you breathe and make sure you are getting enough oxygen during the procedure. Your heart rate, breathing, blood pressure, and other signs are watched carefully during the procedure. You may feel some confusion as you wake up after the surgery. This will disappear as the effect of anaesthetic agent wears off.
Post procedure:
For initial few hours you may experience some confusion, vomiting or nauseous sensation, this will gradually pass off. Depending on your surgery and intraoperative condition you may be sent to an intensive recovery unit before being shifted to return care wards. Each procedure or type of surgery requires different follow-up. You will be informed by your doctor regarding the same.
Possible complications/ risks of anesthesia:
Risks from local and regional anesthesia include:
- Minor discomfort because the anesthetic may not numb the area enough.
- Allergic reaction to the anesthetic, causing fever, nausea, vomiting, swelling, hives, or trouble breathing.
- You may have long-term damage to the nerves.
- You may have trouble breathing because the anesthetic can affect the respiratory system.
- Rarely, you may react by having seizures, dizziness, loss of consciousness, or cardiac arrest.
Risks from general anesthesia include:
- Nausea and vomiting, sore throat, and muscle pain.
- irregular heartbeat (arrhythmia).
- Confusion after the anesthesia (Delirium).
- In rare cases, you may have a heart attack, stroke, or brain damage, which could result in death.
The probability of the above risks is low, although serious injury can result from any type of anaesthesia. As general anesthesia affects all areas of our body, including heart and lungs, side effects are more common than with local or regional anesthetics. Local or regional anesthesia is considered safer than general anesthesia. However, since any of the anaesthetic drug can cause allergic reactions, a small but definite probability of adverse effects remain.