Sedation

Key takeaways

Sedation belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Sedation to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Sedation from memory before moving on to harder problems.

Reference excerpt

Sedation is the reduction of irritability or agitation by administration of sedative drugs, generally to facilitate a medical procedure or diagnostic procedure. Examples of drugs which can be used for sedation include isoflurane, diethyl ether, propofol, etomidate, ketamine, pentobarbital, lorazepam and midazolam.

Medical uses Sedation is typically used in minor surgical procedures such as endoscopy, vasectomy, or dentistry and for reconstructive surgery, some cosmetic surgeries, removal of wisdom teeth, or for high-anxiety patients. Sedation methods in dentistry include inhalation sedation (using nitrous oxide), oral sedation, and intravenous (IV) sedation. Inhalation sedation is also sometimes referred to as "relative analgesia". Sedation is also used extensively in the intensive care unit so that patients who are being ventilated tolerate having an endotracheal tube in their trachea. It can also be used during a long term brain EEG to help patient relax.

Risks There are studies claiming that sedation accounts for 40 percent to 50 percent procedure-related complications. Airway obstruction, apnea, and hypotension are not uncommon during sedation and require the presence of health professionals who are suitably trained to detect and manage these problems. Aside from the respiratory depression, risks also include unintended levels of sedation, postoperative somnolence, aspiration, and adverse reactions to sedation medications. Complications could also include perforation, bleeding, and the stimulation of vasovagal reflexes. To avoid sedation risks, care providers conduct a thorough pre-sedation evaluation and this process includes pre-sedation history and physicals with emphasis on the determining characteristics that indicate potential risks to the patient and potential difficult airway management. This process can also reveal if the sedation period needs to be prolonged or additional therapeutic procedures are required.

Levels of sedation Sedation scales are used in medical situations in conjunction with a medical history in assessing the applicable degree of sedation in patients in order to avoid under-sedation (the patient risks experiencing pain or distress) and over-sedation (the patient risks side effects such as suppression of breathing, which might lead to death). Examples of sedation scales include MSAT (Minnesota Sedation Assessment Tool), UMSS (University of Michigan Sedation Scale), the Ramsay Scale (Ramsay, et al. 1974) and the RASS (Richmond Agitation-Sedation Scale). The American Society of Anesthesiologists defines the continuum of sedation as follows:

Minimal sedation – normal response to verbal stimuli. Moderate sedation – purposeful response to verbal/tactile stimulation. (This is usually referred to as "conscious sedation") Deep sedation – purposeful response to repeated or painful stimulation. General anesthesia – unarousable even with painful stimulus. In the United Kingdom, deep sedation is considered to be a part of the spectrum of general anesthesia, as opposed to conscious sedation. In addition to the aforementioned precautions, patients should be interviewed to determine if they have any other condition that may lead to complications while undergoing treatment. Any head, neck, or spinal cord injuries are noted as well as any diagnosis of osteoporosis.

Intravenous sedation The most common standard conscious sedation technique for adults is intravenous sedation using Midazolam. Indications:

Reduced dental anxiety and phobia Traumatic or prolonged dental procedures Patients with gag reflex Medical conditions potentially aggravated by the stress of dental treatment Special care (mild intellectual or physical disability) Some disorders involving its spasticity due to its muscle relaxant properties Contraindications:

Uncooperative patient Psychologically immature individuals Patients unable to provide a suitable escort Difficult oral surgery or prolonged surgical procedure Muscle diseases or diseases which cause muscle wastage ASA III or above Allergy or hypersensitivity to benzodiazepines Pregnancy and breast feeding History of psychiatric disorders Kidney or liver dysfunction Acute pulmonary insufficiency Preexisting respiratory conditions as patients are susceptible to respiratory depression Alcohol or drug addiction Lack of visible superficial veins

Sedation for pediatric patients

Present drugs commonly used to sedate children: Methohexital; Thiopental; Benzodiazepines; Diazepam; Midazolam; Ketamine; Opioids; Morphine; Meperidine; Fentanyl. Whenever it is necessary to sedate a child, one must consider the type of procedure planned (painful or nonpainful), the duration of the procedure (important in choosing the appropriate sedative), the underlying medical condition of the patient (proper fasting, contracted blood volume, interaction with other medications, and intact mechanisms of drug elimination), the need for anxiolysis or narcosis, and experience with alternative techniques or routes of administration. A child undergoing a procedure that is nonpainful (e.g., CT scan or small laceration infiltrated with local anesthetic) does not require a narcotic. Conversely, a child undergoing a painful procedure may require an opioid.

See also Palliative sedation Procedural sedation Sedoanalgesia Twilight anesthesia

References

External links

Illustrations

Worked examples

Example 1 — a first encounter with Sedation

Start with the simplest possible case. Write down what Sedation claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Sedation before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Sedation ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Sedation

In research: Sedation appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Sedation in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Sedation is common in secondary-school and first-year university syllabi. It links to neighbouring topics Anesthesia, so understanding it makes those chapters shorter.
In everyday life: Look for Sedation outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Sedation in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Sedation means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Sedation out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Sedation in simple terms?

Sedation is the reduction of irritability or agitation by administration of sedative drugs, generally to facilitate a medical procedure or diagnostic procedure. Examples of drugs which can be used for sedation include isoflurane, diethyl ether, propofol, etomidate, ketamine, pentobarbital, lorazepa…

Why does Sedation matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Sedation?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Sedation.