General anaesthesia Home A-Z Health Information Health Library A-Z General Anaesthesia Overview General anaesthesia is the most well-known form of anaesthesia. wherein a drug (anaesthetic) is provided through a mask or is directly injected into the veins (intravenous injection) to artificially put the patient to sleep and make them insensitive to pain (unable to feel pain) during surgery. In some cases, a tube might be placed in your throat (intubation) to help with breathing.Many lifesaving and life-altering surgical procedures rely heavily on general anaesthesia as it enables medical professionals to perform prolonged, intricate, or invasive (involving access to internal tissues and organs by cutting the skin, inserting instruments, or penetrating the natural body openings) operative procedures—such as open-heart surgery, knee and hip replacement, organ transplant, tumour resection (removal), brain surgery, and abdominal surgery for ruptured organs—by ensuring that the patient remains unconscious, immobile (without movement) but relaxed, and pain-free. Without general anaesthesia, many of our surgical breakthroughs would not have been possible. Benefits General anaesthesia plays a central role in creating an optimal operation environment by ensuring the following:Complete immobility: By allowing full control over airway (the route that air takes to reach the lungs when one breathes, i.e., nose, mouth, throat, and windpipe), breathing, and circulation, general anaesthesia minimises undue stress to the patient, thereby ensuring complete body relaxation and stillness during surgical procedures.Flexibility: General anaesthesia allows for multiple surgical procedures to be performed simultaneously (at the same time) or consecutively (on after another) on different parts of the body.Freedom of movement for doctors: General anaesthesia can be administered without moving the patient from supine (lying on back with face up) or any other relevant position.Minimal psychological trauma: Patients who have undergone general anaesthesia have no memory of the operation, which can help reduce psychological trauma.Control over bodily functions: During general anaesthesia, anaesthesiologists are able to monitor and adjust vital functions like blood pressure, breathing, and heart rate during surgery, enabling stability during lengthy and complex surgical procedures.Broad applicability: General anaesthesia is suitable for use with surgical procedures of all lengths and complexities, all the while maintaining patient comfort throughout the procedure.Improved surgical precision: As general anaesthesia prevents involuntary movements (unexpected patient movements), surgeons can operate smoothly with minimal interference from patient reflexes or movements. Technique General anaesthesia is a carefully controlled process that involves multiple steps to ensure that the patient remains unconscious, immobile, and pain-free, while allowing for constant monitoring and adjustment of their vital functions during surgery. The key steps in general anaesthesia include:Preoperative assessment: Before administration of anaesthesia, the anaesthesiologist evaluates the patient’s medical history, current health, and any potential risks, while also taking into consideration factors like allergies, medications, and previous reactions to anaesthesia.Induction (starting the anaesthesia): This process typically involves the use of intravenous (IV) anaesthetic drugs like propofol or etomidate or inhaled gases to induce unconsciousness (sleep) within seconds. Following this, vital signs are closely monitored to ensure that the patient reaches the desired level of unconsciousness.Airway management: To ensure that the patient can breathe properly while being unconscious, the anaesthesiologist secures the airway by inserting a breathing tube (endotracheal tube) into the windpipe (trachea) or using a laryngeal mask airway (LMA). Then, the airway is connected to a ventilator to ensure that the patient gets sufficient oxygen during the operation.Maintenance (sustaining anaesthesia): Once the patient is unconscious, the anaesthesiologist maintains anaesthesia throughout the procedure using a combination of inhaled anaesthetic gases (e.g., nitrous oxide, sevoflurane, isoflurane) and intravenous (IV) medications (e.g., propofol, fentanyl, and muscle relaxants), while adjusting the dose of the drugs based on surgical needs, procedure duration, and patient condition.Monitoring: During the surgical procedure, the vital signs of the patient are continuously monitored to ensure that the patient remains stable throughout the operation.Emergence (waking the patient): Once the procedure is complete, the anaesthesiologist starts the emergence phase by gradually reducing the dose of the anaesthetic drugs, and the patient is allowed to wake up as the medications wear off. Once the patient is fully awake and able to breathe unassisted, the airway device(s) are removed.Postoperative care: After the patient emerges from anaesthesia, they are monitored for any anaesthesia-related complications, such as nausea (vomiting sensation) or difficulty in breathing; this monitoring is done till the patient is fully awake, alert, and stable. Pain relievers might be provided to reduce pain. Risks General anaesthesia is generally safe when administered by a trained professional, but like any other medical procedure, it is associate with some risks. These risks can vary depending on parameters, such as patient’s age and overall health, and the type of surgery being performed. Based on the type of risk, the potential risks associated with the use of general anaesthesia are:Short-term risks (very common risks that resolve quickly):Nausea and vomiting: These are very common after surgery and can be managed with medication.Sore throat or hoarseness: Intubation with a breathing tube might result in sore throat or hoarseness.Shivering or chills: This is caused by a drop in body temperature during surgery.Drowsiness or confusion: This is quite common in older patients.Less common risks:Allergic reactions: These are caused due to possible reactions to the anaesthetic drugs.Breathing problems: Patients with conditions like sleep apnoea might experience difficulty in breathing after a surgical procedure.Heart Problems: Changes in heart rate during the surgery are likely in individuals with pre-existing heart conditions.Lung Complications: The contents of the stomach can enter the lungs (aspiration) if fasting guidelines are not followed. Pneumonia and/or other breathing issues can occur in rare cases.Oral damage: Mouth, teeth, lips, gums, and/or tongue can get damaged as a result of intubation.Rare but serious risks:Anaesthesia awareness: This is an extremely rare condition where the patient becomes conscious during the procedure.Nerve Injury: Immobility for extended periods during an operation can sometimes result in nerve damage.Stroke/Heart attack: Though stroke and heart attack are extremely rare during anaesthesia, they might occur due to any underlying health issues or (in some cases) surgical stress.Malignant hyperthermia: This is a life-threatening genetic reaction to particular anaesthetic drugs, in which the patient develops high fever and muscle rigidity.Cognitive effects: In elderly patients, general anaesthesia might cause memory loss or difficulty in concentration.Death: In extremely rare cases (in around 1 in 100,000 to 200,000 people), general anaesthesia can cause death. This is usually related to severe underlying medical conditions.