induction agents Flashcards
Is propofol an acid or a base and what is its PKA?
weak acid
11
what chemical is propofol derived from?
phenol derivative
what is the Vd for propofol?
4L/kg
how much protein binding does propofol have?
98%
what is the elimination half life of propofol?
5 hours
how does propofol work as an anti-emetic?
D2 antagonism
at what effector site target conc of propofol will patients be asleep?
2.5-3ug/ml
which has more incidence of allergy thiopentone or methohexital?
methohexital
which has more tissue damage on intra-arterial injection thiopentone or methohexital ?
thiopental
how do Thiopental and pentobarbital compare?
both derived from barituric acid
thiopentone is a sulphur analogue of pentobarbital
pentobarbital has a =0 instead of S
how does solubility of thiopental change in different pHs?
The solubility of barbiturates increases on transformation from the keto to enol form, called tautomerism
what is barbituric acid derived from?
Barbituric acid is a condensation product of urea and malonic acid.
what is the pka of thiopentone? at what pH is it kept in solution?
7.6 - weak acid
pH 10.5 - ionised so soluble
in what form is thiopentone soluble?
enol form
which has a faster clearance thiopental or methohexital?
methohexital
what is the dose of thiopentone and methohexital?
he dose of thiopental for induction is 3-7 mg/kg. Methohexital has an induction dose of 1-2 mg/kg.
what is the use of methohexital out of hospital?
ultra short acting
does methohexital cause pain on injection?
yes