Propofol Esmolol

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. 

Several studies have similarly found that the use of esmolol reduced the required dose of isoflurane or propofol, or resulted in a deeper anaesthesia (as measured by BIS), but only in the presence of an opioid. " As there appears to be no pharmacokinetic interaction between esmolol and propofol it has been suggested that esmolol could be interacting with the opioid. ... 

However, in one study 60 patients were given one of three treatments before induction of anaesthesia with propofol esmolol 1 mg/kg followed by an infusion of250 micrograms/kg per minute midazolam or placebo (sodium chloride 0.9%). No opioids were given. Esmolol and midazolam reduced the required induction doses of propofol by 25% and 45%, respectively. Esmolol reduced the mean heart rate by 7.6 bpm compared with placebo in the pre-induction period, and the only adverse effect noted was a transient episode of bradycardia (44 bpm) in one patient receiving esmolol. Esmolol reduces cardiac output by reduction of heart rate and stroke volume and this possibly reduces the required induction dose of propofol by changing its distribution."... 

Another study found that a single 80-mg dose of esmolol after induction of anaesthesia with propofol and either fentanyl or placebo did not affect the depth of anaesthesia (measured by BIS) in either group of patients, even though cardiovascular effects were seen (reduction in systolic arterial pressure and heart late). ... 

Johansen JW,FlaishonR- SebelPS. Esmolol reduces anesthetic requirement for skin incision during propofol/nitrous oxide/morphine anesftiesia. Anes esiology (1997) 86, 364-71. 

Orme R, Leslie K, Umranikar A, Ugoni A. Esmolol and anesthetic requirement for loss of responsiveness during propofol anesthesia, Anesth Analg (2002) 93, 112-16,... 

Wilson ES, McKinlay S, Crawford JM, Robb HM, The influence of esmolol on the dose of propofol required for induction of anaesthesia. Anaesthesia (2004) 59,122-6,... 

Berkenstadt H, Loebstein R, Faibishenko I, Halkin H, Keidan I, Perel A, Effect of a single dose of esmolol on the bispectral index scale (BIS) during propofol/fentanyl anaesthesia, Br JAnaesth (2002) 89, 509-11,... 

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