Anaesthesia is the medical use of medication to block pain and sensation during medical procedures. The word comes from the Greek “an-aisthesia,” meaning “without feeling.” Anaesthetics work by stopping pain signals from reaching the brain. Depending on the type, they can numb just one small area, block sensation in larger regions, or put a patient into a deep, sleep-like state. Anaesthesia is always given by a specialist doctor called an Anaesthesiologist, who chooses the right type and dose, monitors vital signs, and ensures safety before, during, and after surgery.
There are several kinds of anaesthesia. General anaesthesia is the strongest, putting patients into a sleep-like state so they feel nothing during major surgeries such as heart, brain, or organ transplants. Because it suppresses natural reflexes, patients need breathing support and close monitoring. Local anaesthesia is much lighter—it simply numbs a small area, like the gums at the dentist or the skin during a minor procedure, while the patient stays awake and alert. Regional anaesthesia affects larger areas of the body, such as the lower half during childbirth with an epidural, allowing the patient to remain conscious and breathe independently. Finally, sedation makes patients feel relaxed and drowsy and is often combined with local or regional methods to reduce stress and anxiety during procedures. Anaesthesia makes modern surgery safe, effective, and pain-free.
The word “anaesthesia” originates from the Greek word “an-aisthesia”, which means without sensation or perception. In modern medicine, anaesthesia refers to the use of a type of medication (anaesthetic) to stop a patient from feeling pain during invasive medical procedures, usually surgery. The anaesthetic blocks sensory signals from the different parts of the body to the brain. The strength of the anaesthetic used is decided based on its purpose. The strongest anaesthetics put the patient into a completely unconscious state. Milder anaesthetics can be used to numb only specific parts of the body, while keeping other parts active.
Anaesthesia, of any strength, can only be administered under the supervision of a special type of doctor called an anaesthesiologist. The anaesthesiologist can determine the correct type of anaesthesia for the medical procedure the patient is undergoing, as well as the correct dosage for that particular patient.
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General anaesthesia is the strongest type of anaesthesia. It puts the patient into a sleep-like state, using an anaesthetic. The patient is given a combination of intravenous injection and an inhaled gas, to prevent sensory signals from reaching the brain. While under general anaesthesia, the brain doesn’t respond to pain signals or reflexes. The patient’s vital signs, like blood pressure, oxygen levels and heartbeat, are constantly monitored while they are under general anaesthesia. A breathing tube is placed in the patient’s mouth to breathe for them while they are under general anaesthesia. General anaesthesia is considered safe for most patients, however, older adults with serious medical problems may face a higher risk of complications like stroke or heart attack.
General anaesthesia is typically recommended for all open surgical procedures. This includes open heart surgery, joint replacements, organ transplants, gastrointestinal surgery and brain surgery. After the surgery, the anaesthesiologist stops the anaesthetic medicines. Once the medicine is stopped, the effects wear off in a few hours. Patients will be monitored during their post-operative recovery to make sure they don’t feel too much pain or have any complications.
Local Anaesthesia is a mild form of anaesthesia that remains localized to a small part of the body. It can be used to numb a small patch of skin, or gums during minor dental surgery. Local anaesthesia does not put the patient into a state of unconsciousness – They are awake, aware and alert during the medical procedure. However, they do not feel any pain or sensation in the numbed area. The local anaesthetic blocks nerve signals from the peripheral nerves to the brain, without affecting the central nervous system. Reflexes outside the numbed area remain intact.
Local anaesthesia is often used for minor surgical procedures like biopsies, cataract surgery, dental fillings and minor plastic surgery procedures like eyelid lifts and brow lifts. Sometimes patients are given a local anaesthetic spray on the throat before an endoscopy to prevent a gag reflex. Local anaesthesia is often administered topically -through creams, gels, or sprays applied externally.”. However, depending on the zone to be numbed, it could be injected too.
Local anaesthesia usually has no side effects. Some patients may experience temporary dizziness, headaches, blurred vision and muscle twitches, but these symptoms usually resolve on their own shortly after the local anaesthesia wears off. In very rare instances, patients experience an allergic reaction to the local anaesthetic used. However, the anaesthesiologist is always prepared for this scenario and will treat it immediately.
Regional anaesthesia blocks sensation in a larger part of the body – This could be an entire arm, or the entire lower half of the body. The Anaesthesiologist will inject a local anaesthetic around the nerves in the region to be blocked. They often use ultrasound guidance to inject the local anaesthetic precisely into the targeted nerves. The duration of the anaesthesia depends on the dosage and strength of the local anaesthetic used – It can last anywhere from a couple of hours to an entire day. Regional anaesthesia doesn’t affect the central nervous system. This allows the patient to remain conscious and keep breathing independently.
Regional anaesthesia is often used for surgical procedures, in combination with sedation. It is recommended for knee and hip replacement, abdominal surgeries like appendectomies, surgery involving the arm, hand, elbow or fingers, and ophthalmic surgery. It is especially useful during childbirth. The mother is given an epidural, a type of regional anaesthesia, to numb the entire lower body and block pain from the contractions. However, the mother is still conscious, and capable of pushing to deliver the baby.
Regional anaesthesia has a significant advantage over general anaesthesia – There is no need for artificial breathing devices. This greatly reduces potential side effects and helps the patient recover faster. However, regional anaesthesia is not free of risk. Patients may experience nerve injury, temporary neurological weakness or an allergic reaction to the anaesthetic. However, they will be monitored during and after surgery to ensure any complications that arise are treated immediately.
Had been treated by Dr. Sujay Susikar and his team. Overall, it was a satisfactory experience. The surgical team, Anesthesia team and the staff nurses were very good. – Santhi Muthu
Doctors from spine ortho team Dr.balamurali sir, Dr. ‘Keerthivasan sir and Dr. Somasundar sir and anesthesia team did my spine surgery and supported for my better recovery and hospital team did great job .thank you for your service….awaiting for better recovery. – Gayathiri Priyanka. V
Sedation is a mild form of anaesthesia that induces a sleep-like state. It is typically given to patients to make them feel relaxed and drowsy. They will not be totally unconscious but will likely not remember much of what happens while they are sedated. They may or may not fall asleep. Sedation often accompanies local and regional anaesthesia during the surgical procedures mentioned above. Although patients can be conscious with local or regional anaesthesia, many find it deeply unsettling to be awake during surgery. The sedation helps them relax, avoid fear and anxiety and “zone out” during the surgery.
Understanding the different types of anaesthesia helps patients feel informed and confident before undergoing any procedure. At Kauvery Hospital, expert Anaesthesiologist ensure personalized, safe, and well-monitored anaesthesia care across all specialties. With advanced facilities and experienced teams at branches in Chennai, Hosur, Salem, Tirunelveli, and Trichy, Kauvery Hospital is committed to making every surgical experience as safe and comfortable as possible.
What is anaesthesia and why is it used?
Anaesthesia is used to block pain and sensation during medical procedures, allowing surgery to be performed safely and comfortably.
What are the main types of anaesthesia?
The main types are general anaesthesia, local anaesthesia, regional anaesthesia, and sedation, each used to base on the procedure and patient needs.
When is general anaesthesia required?
General anaesthesia is used for major surgeries like heart, brain, organ transplant, or open surgeries where the patient must be fully unconscious.
Will I be awake during local or regional anaesthesia?
Yes, local and regional anaesthesia allows you to stay awake, but the area being treated is numbed so you do not feel pain.
What is sedation and why is it given?
Sedation helps patients feel relaxed and drowsy during procedures and is often used with local or regional anaesthesia to reduce anxiety.
Who decides which type of anaesthesia is used?
A specialist doctor called an anaesthesiologist chooses the safest and most appropriate type of anaesthesia and monitors you throughout the procedure.
Kauvery Hospital is globally known for its multidisciplinary services at all its Centers of Excellence, and for its comprehensive, Avant-Grade technology, especially in diagnostics and remedial care in heart diseases, transplantation, vascular and neurosciences medicine. Located in the heart of Trichy (Tennur, Royal Road and Alexandria Road (Cantonment), Chennai (Alwarpet, Radial Road & Vadapalani), Hosur, Salem, Tirunelveli and Bengaluru, the hospital also renders adult and paediatric trauma care.
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