Flashcards in Benzos, and Barbiturates factoids Deck (20):
Compared to thiopental, methohexital has a ___ duration of action. The duration of thiopental is:___. The duration of methohexital is: ____
Thiopental: 10-30 min
Metho: 5-7 min.
What is a clinical use for barbs?
To reduce ICP. Barbs reduce CMRO2 which decreases CBF and ICP.
Also used in Propofol shortages
What are the effects of barbs on CV, resp, liver, and kidney?
CV: Decreased BP- vasodilation, decreased VR
Resp: Dose dependent depression especially if used in combo. with other resp depressants.
Liver: Enzyme inducers (increases metab. of other drugs)
Kidney: Modest decrease in blood flow from low BP
Do you see skeletal muscle relaxation with barbs?
What are the problems associated with intra arterial injection of barbs?
Arterial spasm, thrombosis, distal limb ischemia
What is the recommended treatment for intra arterial injection of barbs? (2 of them)
1. arterial injection of lidocaine for analgesia and vasodilation
2. brachial plexus block (regional anesthesia) causing analgesia and vasodilation for longer duration
Five principle pharmacological properties of benzos
sedation, anxiolysis, anticonvulsant, spinal cord mediated skeletal muscle relaxation, anterograde amnesia (minimal retrograde)
True or false, benzos provide analgesia and have antiemetic properties.
A benefit to benzos wrt sedation, anxiolysis, and amnesia is that:
The amnesia and anxiolysis lasts longer than the sedation
What are the CV and respiratory effects of benzos?
Minimal CV depression. Minimal resp. depression alone, but potentiate resp depression of other drugs used in combo with benzo. i.e. fentanyl and versed cause increased respiratory depression.
Midazolam: Induction dose and duration of action
0.1-0.3 mg/kg IV, 15-20 min
Compared to prop, ketamine, and etomidate, midaz has a ___ context sensitive half time
Compared to midaz, prop, ketamine, and etomidate, thiopental has a ___ context sensitive half time
Much longer. Even after short infusions of the medication the context sensitive half time is significantly longer and there is a sharp increase after 1 hour infusion duration
What is the mechanism of action of benzos?
Facilitate the mechanism of GABA by binding to an allosteric site and increasing the receptors affinity for endogenous GABA.
Does midaz cross the BBB easily? What does that mean for it's lipid solubility vs water solubility?
Easily crosses means it's highly lipid soluble.
What is the reversal agent for benzos and what is it's duration of action?
Flumazenil- 30-60 min.
Induction dose of Thiopental
3-6 mg/kg IV
Induction dose of Methohexital
25 mg/kg PR for children
Induction dose of diazepam
0.3-0.6 mg/kg IV