Factors associated with patient-reported procedural memory following emergency department procedural sedation with ketamine and propofol: A prospective cohort of 563 patients.

OBJECTIVES: To describe the proportion of patients reporting procedural memory following procedural sedation and analgesia (PSA) with ketamine and propofol (KP) administered premixed together (ketofol) or individually (sequential KP) in ED attendees. Identify any clinical or demographic variables associated with procedural memory.

METHODS: This was a convenience sample of 563 patients who received KP PSA as per the departmental protocol. A standardised script was used to assess for procedural memory. This was categorised as 'any' and 'unpleasant' prior to discharge (immediate memory) and at telephone follow up (delayed memory).

RESULTS: A total of 318 patients had sequential KP and 249 premixed 1:1 ketofol. For sequential KP compared to ketofol, the proportion reporting any memory was as follows: 3.5% versus 3.3% immediate, 4.4% versus 5.5% delayed and 5.4% versus 7.4% for the sum of these. For unpleasant memory, the proportion was as follows: 1.6% versus 2.9% immediate, 1.7% versus 4.7% delayed and 2.2% versus 6.9% all unpleasant memory (odds ratio [OR] 3.3, 95% confidence interval [CI] 1.4-8.1). Memory was associated with male sex (OR 4, 95% CI 1.5-10.5), opiates (OR 3, 95% CI 1.7-7.5), a Wisconsin Sedation Scale score ≥3 (moderate sedation) (OR 4.3, 95% CI 1.1-18.2) and propofol dose <0.75 mg/kg compared to >0.75 mg/kg (13% versus 3%) (OR 6, 95% CI 1.7-21). The ketofol group had 5% (95% CI 0.1-10) more respiratory events requiring intervention.

CONCLUSIONS: Procedural memory was uncommon for both mix types; however, a greater proportion of the premixed ketofol group had unpleasant memory. Associations with sex, opiates, moderate sedation and propofol dose were identified, and respiratory adverse events were more common in the premixed ketofol group.