We have tabulated the series of steps in infusion rate required to maintain constant arterial levels of thiopentone and methohexitone. The tables are based on multiexponential equations for infusion rate, derived from plasma drug efflux studies. In each table an initial bolus is followed by nine steps in infusion rate over three hours. The tables provide rates suitable for delivery by a standard syringe pump to achieve and maintain an arterial concentration of 10 mg/l of thiopentone and 5 mg/l of methohexitone. Other desired drug concentrations can be derived from the table by simple multiplication.
CrankshawD.P., BoydM.D., BjorkstenA.R.Plasma Drug Efflux — A new approach to optimization of drug infusion for constant blood concentration of thiopental and methohexital. Anesthesiology1987; 67: 32–41.
2.
CrankshawD.P.Hypnotics in infusion anaesthesia — With particular reference to thiopentone. Anaesth Intens Care1987; 15: 90–96.
3.
CrankshawD.P., EdwardsN.E., BlackmanG.L., BoydM.D., ChanN.H.J., MorganD.J.Evaluation of infusion regimens for thiopentone as a primary anaesthetic agent. Eur J Clin Pharmacol1985; 28: 543–552.
4.
WhiteP.F., DworskyW.A., HoraiY., TrevorA.J.Comparison of continuous infusion of fentanyl or ketamine vs thiopental — Determining the mean effective serum concentrations for outpatient surgery. Anesthesiology1983; 59: 564–569.
5.
KatzR.I., SkeenJ.T., QuartararoC., PoppersP.J.Varied uses of a thiopental infusion. Anesth Analg1987; 66: 1328–1330.
6.
MorganD.J., CrankshawD.P., PrideauxP.R., ChanH.N.J., BoydM.D.Thiopentone levels during cardiopulmonary bypass — Changes in plasma protein binding during continuous infusion. Anaesthesia1986; 41: 4–10.
7.
NussmeierN.A., ArlundC., SlogoffS.Neuropsychiatric complications after cardiopulmonary bypass: Cerebral protection by a barbiturate. Anesthesiology1986; 64: 165–170.
8.
CrankshawD.P., Allt-GrahamJ.ED50 values for thiopentone, methohexitone, propanidid and alfathesin: A clinical experiment. Anaesth Intens Care1978; 6: 36–43.
