Target Controlled Conscious Sedation with Propofol and Remifentanil for the Extraction of Impacted Wisdom Teeth

Abstract

Pain and anxiety have been considered as main factors influencing patient's attitudes for dental treatments. According to serial UK Adult Dental Health Surveys, around half of the UK's adults were anxiousabout dental treatment (Leitch et al, 2007). Moreover,uncontrolled pain and anxiety can evoke harmful responses such as hypertension and tachycardia during dental treatment. For controlling pain and anxiety effectively and safely, new sedation methods have been needed. Recently, a number of more innovative sedation techniques have been investigated including polypharmacy (Ganzberg et al, 2002), intravenous sedation with target controlled infusion (TCI) and patient maintained sedation (Chapman et al, 2006) in dentistry.The popular intravenous sedatives in dentistry are benzodiazepine or propofol. Sometimes, opioids can be combined with propofol or benzodiazepine (Kwak et al, 2006), because they can minimize adverse reactions of drugs and improve pharmacological effects (Amrein et al, 1995).Generally, potent opioids are excellent for pain control but not used alone in sedation because they do not provide adequate level of sedation and may produce undesirable side effects (Kwak et al, 2006) such as nausea, vomiting, bowel dysfunction, urinary retention, pruritus, sedation and respiratory depression or even arrest. On the other hand, a sedative alone can provide sedation, anxiolysis and amnesia (Kwak et al, 2006), but combining sedatives with opioids allows reducing dosage and synergism (Whitwam, 1995). Among them, considering unique pharmacokinetic and pharmacodynamic characteristics (Alvarez et al, 2000) as well as recovery profiles (Glass et al, 1993), propofol and remifentanil are considered as one of ideal drug combinations for sedation. Target controlled infusion (TCI), a computer-assisted intravenous administration of drugs, allows the target plasma and effect-site concentration to reach equilibrium and may produce consistent pharmacodynamic effects (Rai et al, 2007). TCI was first described by Schwilden et al. in early 1980s (Paul et al, 2006). A microcomputer was interfaced to an infusion pump and drug was infused at a rate to replace drug eliminated and transferred to the peripheral tissue (Ronald et al, 2005). The algorithms calculate the infusionrates required to obtain the desired plasma or effect site drug concentration by using pharmacokinetic modeling (Ronald et al, 2005). Since TCI has been introduced, many researchers have estimated parameters, creating their own pharmacokinetic sets such as the Marsh (Diprifusor) and Schnider (Ochestra Base Primea) for propofol and the Minto and the Schnider for remifentanil (AnestFusor Series II Standard, 2009).Now, open TCI systems are provided by many manufacturers, and there is a choice of different dosing models for propofol, remifentanil and other opioids. TCI have been more rapid and accurate in achieving and maintaining desired levels of anesthesia (Glen, 1998) and more effective in maintaining cardiovascular stability compared to traditional weight adjusted infusions (Castro, 2003). Therefore, TCI sedation with propofol and remifentanil may allow us a safe and predictable sedation. However, the reports of TCI sedation with propofol and remifentanil are very rare in dentistry up to now.Since 2006, TCI conscious sedation with propofol and remifentanil for daily clinical practice has been used in Seoul National Dental Hospital. The aim of this study is to describe one year experience of TCI sedation with propofol and remifentanil in order to establish suitable plasma target concentration of propofol and remifentanil for the extraction of impacted wisdom tooth. PU - Korean Dental Society Of Anesthesiology