Howard County Anesthesia Associates



Precedex (Dexmedetomidine)E. N. Asemani, MDFAQWhat are its indications?-Produces sedative-hypnotic and analgesic effects and has been used for sedation in the ICU, as an anesthetic adjuvant during general anesthesia or procedural sedation, opioid sparing effect and for rapid opioid detoxification-The analgesic application is an off-label use with very minimal non-sedative continuous infusion dosing-Although the US Food and Drug Administration has approved its use in ICU patients for a period of 24 hours, the drug has been used for longer periods. Tolerance and tachyphylaxis have been reported when given over 24 hours. -We would only be using this intra-op for the duration of the surgical case. Therefore, there should be no concerns so far as tachyphylaxis/toleranceWhat’s its site of action?-A potent Alpha -2 adrenergic agonist with selectivity for alpha-2 (1600 times more selective for alpha-2 receptors compared to clonidine). -Alpha-2 agonist mechanism helps to block pain signals at molecular levels. Have been found particularly to be useful in perioperative conditions for pain management and minimizing opioid use. Its use causes a significant reduction in need for both intra-op and post-op analgesics when given prior to incision. The analgesic-sparing effect observed after intra-op administration usually lasts up to 24 hours-In addition, it binds to receptors in the locus ceruleus and spinal cord.?This unique property?is what makes this agent particularly attractive for use in patients who benefit from sedation without profound respiratory depressionOther physiological facts?-increases pulmonary vascular resistance and pulmonary artery pressure-Decreases both cerebral blood flow and cerebral metabolic rate while maintain the cerebral blood flow/cerebral metabolic rate ratio. This may be beneficial with ischemic neurological injury-There's also a dose dependent decrease in cardiac output -it will maintain their ventilatory response to CO2, oxygenation and overall?pH ??-Pharmacokinetic properties are NOT affected by age, weight or renal function-94% Protein boundWhat hemodynamic changes can we expect?-Its hemodynamic response to a BOLUS seems to be biphasic: Initially raises the blood pressure (probably the result of vasoconstriction mediated by activation of peripheral postsynaptic alpha-2b receptors) in the first 10 minutes (>20% above baseline)?followed by a decrease in blood pressure within one?hour (<15% below baseline)-Other?BOLUS side effect is bradycardia. Both the hypotension and bradycardia are due to activation of receptor in the medullary?vasomotor center,?leading to a sympatholytic effect-This is the reason why there will be no BOLUS of Precedex by Anesthesia. Infusion ONLY. What to do if have Precedex induced bradycardia?-A bolus of 2 mcg/kg has?resulted in profound sinus brady and even sinus arrest. This can be treated effectively with administration of?anticholinergics such as glycopyrrolate and atropinePLEASE KEEP IN MIND THAT NONE OF THE PHYSIOLOGICAL AND HEMODYNAMIC CONCERNS SHOWN ABOVE HAVE BEEN REPORTED WITH THE LOW CONTINOUS DOSING FOR PAIN MANAGEMENTWhat is the sedation dose?-cited dosing for sedation is1 mcg/kg over 10 minutes followed by an infusion 0.4-0.7 mcg/kg/min What is the analgesic dose?-0.5-1.0 mcg/kg/hr-You no longer need to fill out a special request form to obtain precedex from pharmacy. Ordering on Epic is all it takes. They can tube it or you can go pick it up-The pharmacy still has to mix the solution. So please place your order to pharmacy in time for surgeryHow is it metabolized?-Primarily metabolized in the liver conjugation and N-methylation. Plasma Cholinestrase plays NO role in the metabolismAT THIS TIME WE ARE ASKING THAT PATIENTS WITH MAJOR LIVER DISEASE WOULD NOT RECEIVE PRECEDEX What is the half life?-Elimination half life is 2-3 hours-The context-sensitive half life is affected by the duration of administration and has been reported to range from 4 minutes (following a 10 min infusion) to more than 3 hours (following an 8 hour infusion)What happens when you use Ketamine and Precedex together?The sympatholytic properties of Precedex are balanced with the sympathomimetic properties of Ketamine. No additional pressor intervention typically neededShould we be worried about all of the side effects of Ketamine and Precedex?The physiological concerns/side effects with both drugs are prominent when normal doses are usedKeep in mind our infusions are at an absolute minimum dosing to give us all of the analgesic benefits and no side effects ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download