What is sedation?
Sedation is medically induced temporary depression of consciousness prior to procedures that cause pain or discomfort to patients. Pain relieving medications (analgesics) are also usually administered as an adjunct to sedation.
Sedation and general anesthesia are different levels in a spectrum of consciousness. A person is fully conscious at one end of the spectrum where there is no sedation, and totally unconscious with general anesthesia. In between, the patient experiences various levels of consciousness based on the medication dosage.
What are the types of sedation and anesthesia?
Following are the different levels of sedation:
- Minimal sedation: The patient feels drowsy and relaxed, with minimal effects on bodily sensations.
- Moderate sedation: Moderate sedation is also known as conscious sedation and/or procedural sedation. The patient is semi-conscious, can breathe on their own and respond to stimulation.
- Dissociation: A type of moderate sedation with similar effects, produced by certain drugs which prevent the brain’s higher centers from receiving the sensory stimuli. The patient is dissociated from the surroundings but responds to stimulation.
- Deep sedation: The patient is nearly unconscious and only has purposeful response to repeated and painful stimulation. The patient may need assistance with breathing, but cardiovascular function is usually unimpaired.
- General anesthesia: The patient is completely unconscious and does not respond to any level of pain. The patient will require breathing assistance and cardiovascular function may be impaired.
What medications are used for sedation?
Commonly used sedative and analgesic medication include the following:
Benzodiazepines have an inhibitory effect on the central nervous system and produces sedation and relieves anxiety (anxiolysis). Benzodiazepines also have anticonvulsant and amnesic properties, but lack analgesic effects.
- Midazolam: Rapid onset and short-acting, ideal for minimal and moderate sedation.
- Lorazepam: Can be used as continuous drip for longer duration of sedation. Useful for patients with kidney or liver problems.
- Diazepam: Long-acting and used for longer procedures. Not recommended for use in patients with liver cirrhosis.
Side effects include:
- Respiratory depression leading to low oxygen saturation
- Cardiovascular depression leading to low blood pressure (hypotension) and an increase in heart rate in response (reflex tachycardia)
Barbiturates are potent sedatives with rapid onset and short duration of effects. Barbiturates are commonly used for endotracheal intubation and emergency sedation. Barbiturates are used along with an analgesic medication because they do not have analgesic effects.
Commonly used barbiturates are:
Side effects include:
- Respiratory depression
- Reflex tachycardia
Nonbarbiturate sedatives are medications derived from certain other compounds which have potent sedative properties like barbiturates. These sedatives have a rapid onset and very short duration of action, ideal for deep sedation during short procedures, in combination with analgesics.
Nonbarbiturate sedatives include:
- Propofol: Causes hypotension and low heart rate. Contraindicated in patients with soybean or egg allergies.
- Etomidate: May cause involuntary muscle twitch (myoclonus) and brief adrenal gland suppression, but negligible cardiovascular effects.
Opioids are primarily analgesic medications that also produce anxiolysis and mild sedation, but no amnesia. They are usually administered in combination with benzodiazepines.
- Morphine: Rapid onset and long duration of action. Can cause hypotension and respiratory depression.
- Fentanyl: Rapid onset and short duration of effects. Can cause respiratory depression.
- Meperidine: Has intermediate duration of effects and rarely used for procedural sedation. Can lower seizure threshold.
The nonopioid analgesic commonly used is a dissociative anesthetic with a short duration of action:
Ketamine: Ketamine makes the patient unaware of the surroundings but does not affect breathing. Ketamine with propofol, known as ‘ketofol’ is favored combination for procedural sedation.
Side effects include:
- Laryngeal spasms
- Delirium and hallucinations in patients older than 15
- Excessive bronchial secretions and salivation
- Hypertension and increased heart rate (tachycardia)
- Increased intracranial pressure
The inhalation agent that has been commonly used for years, for sedation and analgesia, especially in pediatric dentistry is:
- Nitrous oxide: Rapid onset and short duration of action. Useful for minor procedures. May cause nausea and vomiting.
Dexmedetomidine is a hypnotic sedative that acts on the central nervous system, producing sedation, anxiolysis, hypnosis and analgesia. It reduces the requirement for opioids. It has a rapid onset and ultra-short duration of action. It has light sedative effects and does not depress respiration. It is used in:
- ICU sedation: For patients under mechanical ventilation, with continuous infusion until they come off the ventilator.
- Procedural sedation: For minor procedures that require patient response to verbal or physical stimuli.
Side effects include:
- Slow heartbeat (bradycardia)
What is reverse sedation?
Reverse sedation is the reversal of the effects of anesthetic drugs after completion of the procedure. Reversal of sedation may also be required if a patient has adverse reactions to the sedative agent or if the level of anesthesia gets deeper than intended due to some reason.
The two reversal agents available are:
Naloxone reverses the effects of opioid anesthetic agents.
- Rebound sedation
- Withdrawal symptoms in patients with chronic opioid use
Flumazenil reverses the effects of benzodiazepines.
- Rebound sedation
- Withdrawal symptoms in patients with chronic benzodiazepine use
- Precipitation of seizures that do not respond to benzodiazepines
Sedation is medically induced temporary depression of consciousness prior to procedures that cause pain or discomfort to patients. Pain relieving medications (analgesics) are also usually administered as an adjunct to sedation. General anesthesia induces full unconsciousness with a breathing machine necessary.
Multimedia: Slideshows, Images & Quizzes
A Visual Guide to Generalized Anxiety Disorder
Learn about generalized anxiety disorder (GAD). See if your worries are normal or something more by learning about symptoms,...
Pain Management: Surprising Causes of Pain
What's causing your pain? Learn the common causes of lower back pain, as well as pain in the knee, stomach, kidney, shoulder,...
Weight Loss Surgery: What to Expect
Are you considering weight loss (bariatic) surgery? WebMD helps you know what makes you a good candidate and the pros and cons of...
Weight Loss Surgery Quiz
What happens after weight loss surgery? What should you eat? Take this quiz to learn about bariatric surgery. Are you a candidate?
Pain Quiz: Test Your IQ of Pain
Is pain all in the brain? Take the Pain Quiz to learn everything you've ever wanted to know about the unpleasant sensation we...
Pain Management: Knee Pain Dos and Don'ts
Your knees go through a lot in the course of a day, and sometimes they can run into trouble. Here are a few things you can do...
First Aid Emergencies: What Heat Can Do to Your Body
Too much heat can make you tired, sick, and woozy. WebMD guides you through these and other things heat can do to your body and...
Emergency Preparedness: Staying Safe in Winter Weather
Emergency preparedness helps you stay safe during and after an emergency. Emergency preparedness kits are available, and...
Related Disease Conditions
7 Reasons You Are Tired After Surgery
Postsurgical fatigue is normal and is due to a variety of factors. Depression, stress, and anxiety may produce fatigue. Sleep deficits, certain medications, anemia, blood loss, fasting, and loss of electrolytes and minerals associated with surgery can also produce fatigue. Exercise, physical exertion, aging, and the overall health status of patients are additional factors that play a role in making people feel tired after surgery.
Does Your Heart Rate Increase When Healing From Surgery?
After surgery, your heart rate may increase. The condition is called postoperative tachycardia, in which heart rates are higher than 100 beats per minute.
ICU psychosis is a disorder (also a form of delirium or acute brain failure) in which patients in an intensive care unit or a similar setting experience a cluster of serious psychiatric symptoms. These symptoms include: anxiety, reastlessness, hearing voices, hallucinations, nightmares, paranoia and more. Causes of ICU psychosis are generally from a combination of environmental and medical conditions.
How Long Does It Take to Recover From Laparoscopic Surgery?
When done for the treatment of medical conditions, the recovery may vary depending on the type of treatment. After a major surgery, such as a laparoscopic hysterectomy (removal of the uterus), removal of the ovaries or removal of a kidney for the treatment of cancer, it may take up to 12 weeks to recover. The patient may be able to resume their activities within 3 weeks of a minor laparoscopic surgery, such as an appendix removal.
Mental health is an optimal way of thinking, relating to others, and feeling. All of the diagnosable mental disorders fall under the umbrella of mental illness. Depression, anxiety, and substance-abuse disorders are common types of mental illness. Symptoms and signs of mental illness include irritability, moodiness, insomnia, headaches, and sadness. Treatment may involve psychotherapy and medication.
Psychotic disorders are a group of serious illnesses that affect the mind. Different types of psychotic disorders include schizophrenia, schizoaffective disorder, schizophreniform disorder, brief psychotic disorder, shared psychotic disorder, delusional disorder, substance-induced psychotic disorder, paraphrenia, and psychotic disorders due to medical conditions.
Brief Psychotic Disorder
Brief psychotic disorder is a short-term mental illness that features psychotic symptoms. There are three forms of brief psychotic disorder. The first occurs shortly after a major stress, the second has no apparent trauma that triggers the illness, and the third is associated with postpartum onset. Symptoms include hallucinations, delusions, unusual behavior, disorientation, changes in eating and sleeping, and speech that doesn't make sense. Treatment typically involves medication and psychotherapy.
First Aid: Why You Need a First Aid Kit and CPR
First aid is providing medical assistance to someone a sick or injured person. The type of first aid depends on their condition. Preparedness is key to first aid, like having basic medical emergency kits in your home, car, boat, or RV. Many minor injuries may require first aid, including cuts, puncture wounds, sprains, strains, and nosebleeds. Examples of more critical first aid emergencies include heart attacks, strokes, seizures, and heatstroke.
How Dangerous Is Brain Surgery?
Brain surgery refers to various medical procedures that involve repairing structural or functional problems in the brain. Neurosurgeons perform different types of brain surgery for different conditions in the brain. The type of brain surgery performed is based on the area of the brain affected and condition being treated. Invasive brain surgery and minimally invasive/endoscopic brain surgery can be performed without any incisions (surgical cuts).
What Is Excisional Surgery?
Excisional surgery or shave excision is a surgical procedure that involves the removal of growths, such as moles, masses and tumors, from the skin along with the healthy tissues around the tumor. The doctor uses this technique to treat skin cancers, where they use a scalpel or razor to remove the tumor.
Is Lumpectomy a Major Surgery?
Lumpectomy is a surgical procedure to remove a mass (cancerous or non-cancerous) from the breasts. In a lumpectomy, only the affected portion of the breast is removed, without removing the surrounding healthy breast tissue. Lumpectomy is also called breast-conserving surgery.
Is a Mastectomy Major Surgery?
Mastectomy is a surgical procedure that involves either partial or total removal of breast tissue to treat or prevent breast cancer and reduce the chances of developing breast cancer. Breast reconstruction may be done along with this surgery.
What Is the Difference Between Plastic Surgery and Cosmetic Surgery?
The terms plastic surgery and cosmetic surgery are often used interchangeably. Although both disciplines of medical science aim at improving a person’s body, they are different from each other in many aspects.
Can You Be Too Heavy for Weight-Loss Surgery?
Weight loss surgery is an effective way for people with significant excess weight to improve their health. There is no official upper limit on weight for weight loss surgery candidates.
What is tracheal reconstruction surgery?
Laryngotracheal reconstruction surgery (LTR) facilitates easier breathing in babies and adults with a narrow airway. It utilizes a piece of cartilage (firm tissue in the body) to reconstruct and improve the airway diameter, as well as improve its structure and functioning.
What Is the Weight Limit for Weight Loss Surgery?
Treatment & Diagnosis
- Colonoscopy Procedure and Preparation
- Cataract Surgery
- Tonsillectomy and Adenoidectomy Surgery
- Lap Band Surgery
- How Dangerous Is General Anesthesia?
- How Do You Infiltrate Local Anesthesia?
- Sigmoidoscopy vs. Colonoscopy
- How Long Does It Take to Recover From Lap Band Surgery?
- Endoscopy vs. Colonoscopy
- How Painful Is a Colonoscopy?
- What Is Reconstructive Foot Surgery?
- Heart Valve Disease Surgery
- What Is a Minimally Invasive Total Hip Replacement Surgery?
- What Is Transpositional Flap Surgery?
- What Is Robotic Surgery Used for?
Medications & Supplements
- What Drugs Are Used for Conscious Sedation?
- What Does Sedation Feel Like?
- Anectine (succinylcholine chloride)
- Is Procedural Sedation the Same as Moderate Sedation?
- Bridion (sugammadex)
- What Are Opioid Equivalents and Conversions?
- Atropen (atropine)
- Biorphen (phenylephrine hydrochloride)
Prevention & Wellness
- Alzheimer's Genes Might Also Raise Odds for Epilepsy
- Ketamine Beats Shock Therapy in Easing Tough-to-Treat Depression
- Most Americans Don't Know What 988 Suicide Crisis Hotline Is For: Poll
- Nowhere Safe to Play: 'Play Deserts' Keep Kids from Fun Physical Activity
- Hi-Tech Implant Helps Paralyzed Man Walk Naturally Again
- More Health News »
Health Solutions From Our Sponsors
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.