Sedation and GA Flashcards
Define conscious sedation:
A technique in which the use of a drug/drugs produces a state of depression of the CNS enabling treatment to be carried out, verbal contact with the patient is maintained throughout the period of sedation. Drugs and techniques used to provide conscious sedation for dental treatment should carry a margin of safety wide enough to render loss of consciousness unlikely.
What is inhalation sedation?
- use of nitrous oxide and oxygen
- delivered as a gas via nose piece mask
- ability to breathe through nose
- mild sedation
- anxiolytic effects
- analgesic effects
List some properties of nitrous oxide:
- rapid onset of action (3-5 minutes)
- crosses blood-brain barrier rapidly
- elimination also rapid
- no significant metabolism by kidneys or liver
- not stored in tissues
- no hangover effect
What are some side effects of nitrous oxide?
- headaches
- nausea
- vomiting
- diffusion hypoxia - when nitrous oxide is discontinued, leaves blood quicker than nitrogen from air is absorbed, leading to dilution of oxygen in the lungs
Administer 100% oxygen after cessation of nitrous oxide for 5 minutes to prevent this
What are indications of inhalation sedation?
- mild anxiety
- needle phobia
- patient not suitable for IV/GA
- straightforward dental treatment
Must be able to cooperate: age, learning disability/cognitive impairment, ability to tolerate mask - mask may impede access to anterior teeth
What are the contraindications of inhalation sedation?
- generally safe and well tolerated
- COPD
- recent eye or ear surgery
- mask intolerance
- pregnancy
- vitamin B12 deficiency
- methotrexate interaction ?drug holiday
- chemotherapy interaction
What is intravenous sedation?
- most commonly midazolam delivered by an injection
- mild-moderate dental anxiety
- need to cannulate
- need an escort, required to follow rules
- amnesia (memory loss)
- must also have reversal drug - flumazenil
What are some contraindications for IV sedation?
- needle phobia
- medical reasons
- social reasons
- pregnancy
- poor venous access
What is oral sedation?
- delivered as a drink, usually midazolam
- must still cannulate for safety
- proficient in IV technique
What is a pre-medication?
- preliminary administration of a drug preceding a diagnostic, therapeutic or surgical procedure as an antibiotic or antianxiety agent
What are contraindications of pre-meds?
- hepatic impairment
- renal impairment
- pregnancy
- breastfeeding
Cautions: - avoid prolonged use
- reduced dose in debilitated and elderly patients
- respiratory disease
Define general anaesthesia:
A general anaesthetic is a state of controlled unconsciousness affecting the whole body, so the patient does not move or feel pain, with loss of protected reflexes. An anaesthetist uses a combination of medicines to allow medical procedures to be carried out, that otherwise would be intolerable to the patient
What are some indications for GA?
- lengthy or complex procedure
- very anxious patients/profound learning disability who are unable to tolerate with treatment under IV/inhalation sedation
- multiple extractions in multiple quadrants
- severe trauma or acute dental infection
- nitrous oxide or IV sedation contraindicated
What are disadvantages of GA?
- treatment often more radical to be done in one visit
- open consent often needed as cannot wake patient to discuss half way through
- does not help patient get over fear/build confidence
- cost
- pre-op fasting and after care required
- risk - morbidity and mortality
