NEW YORK (Reuters Health) – The combination of ketamine with propofol, known as ketofol, offers little advantage over propofol alone for emergency department procedural sedation and analgesia, in particular with regard to respiratory depression, a Canadian team reports in the Annals of Emergency Medicine online March 9.
“Using the widely accepted intervention-based Quebec Criteria, we found that, when targeting deep sedation, the incidence of adverse respiratory events is not lessened when a 1:1 single-syringe mixture of ketamine and propofol is used compared with using propofol alone,” the authors conclude.
“Sedation with the combination ‘ketofol’ has become extremely popular,” the journal editor notes. Lead author Dr. Gary Andolfatto, at the University of British Columbia, Vancouver, and colleagues explain that propofol is associated with respiratory depression and in theory this could be counterbalanced by ketamine, which is known to preserve respiratory function.
To test this, the team randomized 284 patients seen in the emergency department for procedures such as fracture reduction or abscess incision and drainage, to receive sedation and analgesia with ketofol or propofol.
They found that rates of adverse respiratory events were 30% versus 32% in the two groups, respectively, a nonsignificant difference (p=0.8).
“It is possible that the relatively rapid dosing regimen used in this study (every 1 minute, rather than the commonly used every 3-minute schedule) offset any protective effect provided by the reduction in total propofol dosage,” Dr. Andolfatto and colleagues suggest.
“Alternatively, it may be that such a protective effect does not exist,” they conclude.
Secondary outcomes such as induction time and sedation efficacy were similar, although sedation depth seemed better with ketofol. Specifically, 46% of patients receiving ketofol and 65% of those given propofol required repeated dosing during their procedures.
The journal editor concludes in a capsule summary: “The major purported benefits of ketofol over propofol alone were refuted in this largest and most rigorous study yet. The modest enhanced sedation consistency observed with ketofol is of uncertain clinical benefit.”