A recent study in the journal Anesthesiology showed that the common drug Ritalin, or methylphenidate, can quickly reverse the effects of propofol. The research was done by Jessica Chemali B.E.; Christa Van Dort, Ph.D.; et al. out of the Massachusetts General Hospital. They conducted several studies on the emergence from propofol anesthesia in rats who were given Ritalin.
Their first study used rats who were given a propofol IV bolus of 8 mg/kg. That amount, by the way, is pretty large since the usual induction dose for propofol in humans is only 1-2 mg/kg. One set of rats was then given a normal saline bolus while another set was given a bolus of IV Ritalin. The rats given NS redeveloped their righting reflex with a median time of 735 seconds. The rats given Ritalin started righting themselves at a median time of 448 seconds, or almost a 40% improvement in recovery.
In a second set of experiments, the rats were given propofol infusions through their tail veins. After achieving a concentration of propofol that kept the rats supine, NS was injected into the rats along with the removal of a stimulatory probe. This produced no changes in their activities. Then IV methylphenidate was given to the rats . All the rats started exhibiting signs of arousal such as kicking or blinking, with complete righting at a median time of 82 seconds.
This is very promising research and is good news for anybody who has ever had difficulty arousing a patient after giving propofol anesthesia, ahem Dr. Murray. Once again, because of our profession's single-minded pursuit of patient safety, research may be pointing the way towards even safer anesthesia.
But here is where the situation becomes difficult for anesthesiologists. The administration of propofol has been widely cautioned in the past as having no antidote. Therefore we have always recommended that only doctors with years of training in injecting propofol should be giving it to patients either in procedure rooms or the ICU. Now that there may be a reversal agent for the drug, will this give the gastroenterologists, CRNA's, cardiologists, and virtually anybody who wants to sedate a patient an opening to claim more cases from anesthesiologists? Once narcotics and benzodiazepenes could be reversed quickly and safely, they became drugs that could be given by virtually anyone with some sort of medical license. Will Ritalin's ability to rapidly produce emergence from propofol anesthesia lead to a similar calamity for anesthesiologists? Damn you Mass General and your overachieving researchers.