Propofol concentration

Dawidowicz, A.J. et al., Influence of propofol concentration in human plasma on free fraction of the drug, Chem. Biol. Int., 159, 149, 2006. 

Fan, S.Z. Yu, H.Y. Chen, Y.L. Liu, C.C. Propofol concentration monitoring in plasma or whole blood by gas chromatography and high-performance liquid chromatography. Anesth.Analg., 1995, 81,... 

A study in 20 patients undergoing spinal anaesthesia with tetracaine found that propofol sedation (as measured by bispectral index monitoring (BIS)) was enhanced when adrenaline was added to the intrathecal tetracaine." A study in sheep found that adrenaline, noradrenaline and dopamine decreased propofol concentrations during a continuous propofol infusion, with the result that propofol anaesthesia was reversed. This was thought to be due to increased first pass clearance of propofol secondary to increased cardiac output. It was concluded that this could be of clinical importance if propofol is used in hyperdynamic circulatory conditions induced by either catecholamine infusions or disease states such as sepsis. ... 

Myburgh JA, Upton RN, Grant C, Martinez A. Epinephrine, norepinephrine and dopamine infusions decrease propofol concentrations during continuous propofol infusion in an ovine model. Intensive Care Med (200 ) 27, 276-82. 

Perl, T. Carstens, E. Him, A. Quintel, M. Vautz, W. Nolle, J. Juenger, M. Determination of serum propofol concentrations by breath analysis using ion mobility spectrometry, Br. J. Anesth. 2009,103, 822-827. 

Propofol PK are unaltered by established renal failure the time interval between cessation of a propofol infusion and eye opening is significantly shorter in renal failure patients than controls, although blood propofol concentrations are not significantly different on waking [47]. 

Grossherr, M., Hengstenberg, A., Meier, T. et al. (2007) Discontinuous monitoring of propofol concentrations in expired alveolar gas and in arterial and venous plasma during artificial ventilation. Anesthesiology 104,786. 

Takita, A., Masui, K., Kazama, T. (2007) On-line monitoring of end-tidal propofol concentration in anesthetized patients. Anesthesiology 106, 659. 

A report on the binding of the anesthetic propofol to human serum albumin and to plasma presents a dataset that challenges simple notions of equilibria [70]. The unbound fraction of propofol was found to increase sharply at low drug concentrations. The authors appear to have carefully eliminated possible artifacts. Explanations based on cooperative binding modes are discussed though no clear explanation emerges. 

The changes in plasma and effect site concentrations following an intravenous bolus of propofol is shown in Figure 2.13. If the plasma concentration of a drug were instantaneously increased to a higher steady state concentration. 

Unlike isoflurane, desflurane may stimulate the sympathetic nervous system at concentrations above 1 MAC. Sudden and unexpected increases in arterial blood pressure and heart rate have been reported in some patients, accompanied by increases in plasma catecholamine and vasopressin concentrations and increased plasma renin activity. These pressor effects may increase morbidity or mortality in susceptible patients. The mechanism of sympathetic activation is unclear but does not appear to be baroreceptor-mediated. Clonidine, esmolol, fentanyl and propofol partially block the response but lignocaine (lignocaine) is ineffective. 

There is good evidence that propofol exerts an anti-emetic effect. The mechanism of this is unclear, but animal studies have shown that it may involve depleting the area postrema of serotonin as well as direct GABA-mediated inhibition, or inhibition of dopamine release in the brain. This probably requires a plasma concentration of over 350 ng-mL-1, and therefore will be seen when propofol is used as an induction agent for very short cases, or when it is used as an infusion in longer cases. Nitrous oxide... 

Propofol lOmg/mL Soybean oil, concentrated glycerin, egg yolk lecithin, edetate 19,451.2 852.5... 

Severe lactic acidosis occurred in a 7-year-old child with osteogenesis imperfecta during short-term (150 minutes) propofol infusion anesthesia (mean infusion rate 13.5 mg/kg/hour) (949). The peak arterial lactate concentration occurred 160 minutes after withdrawal of propofol (lactate 9.2 mmol/1, bicarbonate 16 mmol/1, base deficit 8.3 mmol/1). The hyperlactatemia settled within 18 hours. 

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