These levels of sedation under anesthesia are defined by the American Society of Anesthesiologists (ASA) and are crucial in determining the appropriate level of sedation for each patient and procedure, ensuring patient safety and comfort throughout the perioperative period.
Minimal Sedation: Also known as anxiolysis, minimal sedation involves a drug-induced state during which patients respond normally to verbal commands. Their cognitive function and physical coordination remain unaffected, and there is no compromise in airway reflexes or protective reflexes. This level of sedation is commonly used for procedures requiring minimal discomfort or anxiety relief, such as minor dental procedures or diagnostic tests.
Moderate Sedation/Conscious Sedation: Moderate sedation, also referred to as conscious sedation, induces a drug-induced depression of consciousness, during which patients respond purposefully to verbal or light tactile stimulation. While maintaining spontaneous ventilation, patients may experience decreased anxiety and may have impaired cognitive function and physical coordination. However, they retain the ability to maintain their own airway and respond to commands. This level of sedation is commonly used for procedures such as endoscopic examinations, minor surgeries, or interventional radiology procedures.
Deep Sedation: Deep sedation involves a drug-induced depression of consciousness, during which patients may not respond purposefully to verbal or tactile stimulation. Patients under deep sedation may require assistance in maintaining their airway, and spontaneous ventilation may be inadequate. However, patients still maintain cardiovascular function. This level of sedation is often used for procedures requiring significant analgesia and amnesia, such as major surgical procedures or certain diagnostic imaging studies.
General Anesthesia: General anesthesia involves a drug-induced state during which patients are unarousable, even in the presence of painful stimulation. Patients under general anesthesia require assistance in maintaining their airway and ventilation, and cardiovascular function may be impaired. General anesthesia is characterized by a complete loss of consciousness and protective reflexes, allowing for surgical procedures to be performed without pain or awareness. This level of sedation is utilized for major surgical procedures or invasive diagnostic procedures where unconsciousness and muscle relaxation are necessary.
Procedural sedation and analgesia (PSA) is a technique in which a sedating/dissociative medication is given, usually along with an analgesic medication, in order to perform non-surgical procedures on a patient. The overall goal is to induce a decreased level of consciousness while maintaining the patient's ability to breathe on their own. Airway protective reflexes are not compromised by this process