ivrn asked
Our office infuses ketamine 0.5mg/kg in 100ml normal saline. Since the minibag saline crisis, we are now using syringe pumps to administer the ketamine. Since changing to the syringe we have noticed our patients do not seem to have as intense of an experience (dose of ketamine and amount of saline is the same as pre-syringe). Is there any reason why this would happen?
Answer
The reaction to ketamine post-anesthesia can be impacted by a variety of factors including the way the medication is administered. Due to the saline shortage, administration of many drugs, such as ketamine has been impacted. These changes sometimes have an impact on patient care.
Assuming the dose and concentration of the ketamine in saline
(0.9% sodium chloride) is the same, the
rate of infusion could be the important variable that is changing the
patient experience. It is important to double check the syringe pump settings and
standardize the infusion rate when possible. When given intravenously, ketamine
must be given over at least 60 seconds as
rapid administration can cause respiratory depression. Ketamine can sometimes
be given intramuscularly and is thought reduce the chance of a patient having
the post-anesthesia reaction.
Emergence Phenomenon
Ketamine is a sedative that is used for general anesthesia for a variety of procedures in both the inpatient and outpatient settings. Ketamine administration commonly (~12%) causes an “emergence phenomenon” after patients waken from anesthesia. This can cause a variety of symptoms including hallucinations, delirium, disorientation, amnesia, aggression, and irrational behavior. Sometimes the experience can be described as pleasant, but the experience varies by the person. Ketamine is a controlled substance because of its abuse potential and has been used as a “date rape” drug.
The intensity of a patient’s ketamine experience may be affected
by a variety of factors including:
·
How the drug is administered
·
The dose of the drug
·
Concomitant use of other medications
· Number of stimuli present during recovery
As mentioned previously, giving the drug slower or via
intramuscular route can reduce the risk of the emergence phenomenon. Higher
doses may increase the risk of a patient having a reaction. Reducing the number
of stimuli post-operatively including visual, tactile, and verbal decreases
risk. Using diazepam during anesthesia has been shown to reduce the risk as
well. A short-acting barbiturate may be needed to stop a severe emergence
reaction.
Nationwide saline shortage
Since Hurricane Irma swept past Puerto Rico in September, the nation has faced a critical shortage of a variety of drugs including saline bags. The suppliers of saline bags had a significant portion of their manufacturing facilities located in Puerto Rico. The facilities have dealt with power outages, employee issues, and shipment delays to the United States. The FDA has even allowed for importation of saline bags from outside of the United States.
The nationwide saline bag shortage has required significant
changes in medication administration in both inpatient and outpatient settings.
Many facilities have reported a significant negative impact on patient care in
some instances. At the least, the shortage has caused healthcare providers
including nurses, pharmacists, and IT specialists to work hard to accommodate the
situation. Common changes have been giving more medications IV push, using
syringe pumps or Buretrols, using continuous infusions, and purchasing premade
bags.
Sources: Ketamine
package insert, FDA
announcement, ASHP recommendations
