Anaesthesia Flashcards
Adrenal suppression
Corticosteroid combined with anaesthesia can cause a dangerous fall in blood pressure
Intravenous anasthesia
A topical anaesthetic can be used to reduce pain at the injection site e.g lidocaine (emlar)
Recommended dose as guide, depends on the patient
IV used to induce or maintain anaesthesia
Total intravenous anaesthesia - all drugs given IV
Drugs used for IV anaesthesia
Propofol - most common not in neonates, rapid recovery, less hangover effect, can be used in intensive care
Thiopental sodium - barbiturate, no analgesia can have cardio and respiratory depression, dose related
Ketamine - side effects include hallucinations, nightmares and other psychotic effects
Inhalation anaesthetics
Volatile liquids
Anaesthetics - induction or maintenance of anaesthesia then given IV
Nitrous oxide
Entronox
Inhaled anaesthetic
Maintenance
Not as strong - not used alone
50/50 mix nitrous oxide and oxygen
Self administrated
Used in labour etc
Malignant hyperthermia
Lethal complication, severe reaction
Rapid rise in temperature
Muscle rigidity
Tachycardia
Acidosis - acid in blood decreases pH
Most common if volatile liquid anaesthetic is used
Daritrolene used to treat
Surgery and drugs that shouldn’t be stopped
Too many risks if taking meds and its easier to stop
Drugs that should normally NOT be stopped before surgery include
Anti-epileptics
Antiparkinsonian drugs
Antipsychotics
Anxiolytics
Bronchodilators
Cardiovascular drugs
Drugs that should be stopped during surgery
If taking antiplatlet or oral anticoagulants STOP or switch to heparin/LMWH
Stop COC and HRT 4 weeks before major surgery
MAOI - to withdraw 2 weeks before
Lithium to be stopped before major surgery
Stop potassium sparing - risk of hyperkalaemia
ACEi / ARB or herbal meds
Diabetic drugs to be switched to insulin
Sedation and resus in dental pain
Limited to conscious sedation
Diazepam or temazepam are effective anxiolytics for dental treatment in adults
Pre medication and peri-operative drugs
Drugs that affect gastric pH regurgitation and aspiration of gastric contents
H2 receptor antagonists before surgery
Doesn’t affect pH, give 1-2 hours before
Pre-medicants give night before major surgery
A further, smaller dose may be required before surgery
- benzodiazepines, anxiety, sedation, short acting is best, night and morning before
Benzodiazepines
Diazepam - mild sedation, drowsiness
Temazepam - shorter duration, more rapid than diazepam
Lorazepam - produces more prolonged sedation
Midazolam - water-soluble, better and quicker recovery than IV diazepam
What is used to reverse respiratory depression in opioid use?
Naloxone
What is benzodiazepine antagonist?
Flumazenil
Local anaesthetic drug
Buphacain HCl - longer duration of action, slower onset
Levobupivacaine - isomer of bupivocapine, fewer adverse effects
Lidocaine HCl - lasts 90 mins if with adrenaline/epipherine
Phlocaine HCl - similar lidocaine
Ropivacine HCL - less toxic and effective than bupivacaine
Teracine - local for venepuncture or venous cannulation. Rapid absorption, don’t apply to inflammed surfaces
Administration by injection
Dose depends on injection site, patient age, weight, physique, clinical conditions, duration
Uptake of local anaesthetics into the systemic circulation determines their duration of action and produces toxicity
NHS advice - prior to admin, draw injectable mass from ampules into syringe not be decanted to open containers. Reduce risk of contamination