Ketofol for Procedural Sedation
Answer: 3.
Various mixture regimens of ketamine and propofol have been proposed, citing synergy of effect, balance of side-effect profiles, and fewer airway adverse events when the two medications are used together in lower doses than if given alone. In a recent randomized double-blinded trial (Andolfatto et al, 2012), investigators sought to find at least a 13% absolute reduction in adverse respiratory events with the use of a 1:1 ratio of ketamine and propofol versus propofol alone for procedural sedation in the ED.
Investigators studied 142 subjects in each group, and found that disposition times (1), incidence of adverse airway events (2), and patient, physician, and nurse satisfaction scores were all similar between the two groups (4). Recovery time was similar between the two groups (3).
Emergency physicians or anyone performing sedation should have a good understanding of the pharmacokinetics ("what the body does to the drug") and pharmacodynamics ("what the drug does to the body") of the medications administered. Ketamine can be used as an analgesic at lower doses and as a dissociative and analgesic agent at higher doses. Dissociation is an "all or nothing" threshold. Ketofol is thought not to offer dissociation, but a "propofol sparing" quality. This study suggests that the rate of adverse airway events is similar whether a "propofol sparing" regimen (ketofol) is used versus propofol alone. The clinician should remember that propofol has no analgesic effect; pain should be addressed before and/or during the procedure, if it is used.
In sedation research, there has been a great need to standardize terminology for the pre-sedation assessment, depth of sedation, and adverse events – the Quebec criteria were established to fill this need. First developed for children, they readily apply to adult sedations. The goal was to avoid including features that do not require intervention or change in the sedation plan, such as transient or minor physiologic effects that have no clinical consequence (minor changes in heart rate, respiratory rate, or blood pressure caused by the sedation drug). The Quebec criteria categorize adverse events into the following: respiratory (oxygenation or ventilation-associated and clinically apparent pulmonary aspiration), vomiting, cardiovascular (bradycardia and hypotension), excitatory movements (myoclonus, muscle rigidity, and generalized seizure), adverse behavioral reactions (paradoxic response to sedation and unpleasant recovery reaction), and permanent complications (neurologic injury and death).
Andolfatto G et al. Ketamine-Propofol Combination (Ketofol) Versus Propofol Alone for Emergency Department Procedural Sedation and Analgesia: A Randomized Double-Blind Trial. Ann Emerg Med. 2012; 59:504-512.
Bhatt M et al. Consensus-Based Recommendations for Standardizing Terminology and Reporting Adverse Events for Emergency Department Procedural Sedation and Analgesia in Children. Ann Emerg Med. 2009; 53:426-435.
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