anaesthesia

Anesthesia is a medical specialty that prepares patients for procedures by inducing a reversible state of analgesia, amnesia, and unconsciousness, while maintaining safety and vital organ function. The field covers general anesthesia, regional anesthesia, local anesthesia, and various forms of sedation. General anesthesia renders patients unconscious and insensitive to pain, usually through a combination of intravenous and inhaled agents, muscle relaxants, and analgesics. Regional anesthesia provides loss of sensation to a body region via nerve blocks or neuraxial techniques (epidural or spinal), while local anesthesia numbs a small area. Sedation can be used alone or with regional techniques to ease anxiety or discomfort.

Preoperative assessment evaluates medical history, comorbidities, airway, medications, and risk of complications, guiding anesthesia planning. The intraoperative phase includes induction, airway management (often with an endotracheal tube or laryngeal mask), maintenance of anesthesia with drugs and continuous monitoring of heart rate, blood pressure, oxygenation, ventilation, temperature, and urine output. Drug regimens typically include anesthetics (volatile agents such as sevoflurane; intravenous agents like propofol), analgesics (opioids and non-opioid analgesics), and sometimes neuromuscular blockers with reversal agents. Postoperative care in a recovery area monitors emergence from anesthesia and pain control.

Safety is achieved through standardized monitoring, airway preparedness, fluid management, infection prevention, and vigilance for complications such as nausea, respiratory or cardiovascular instability, and, rarely, malignant hyperthermia. Anesthesiology is practiced by physicians and, in some settings, nurse anesthetists, who work with surgeons and nursing staff to plan and deliver care before, during, and after procedures.