Procedural sedation

Letters

CJEM 2008;10(3):196-197

To the editor: The article by Zed and colleagues1 raises some interesting questions. Could it be that contrary to current belief, propofol does have analgesic/amnesic properties? It would be helpful to know which patients (and their procedures) were given fentanyl. Which patients (and procedures) experienced recall? I suggest that 6.2% recall of a painful procedure is unacceptable. The addition of 1 mg to 2 mg midazolam may be a small price to pay for total absence of recall. Since 1 of the goals of procedural sedation in the emergency department is to have the patient "street ready" in the shortest time possible, is it now time to consider the use of alfentanil or, better still, remifentanil, given the brief duration of pain inflicted by the majority of our emergency department interventions?

Seamus Donaghy
Grimsby Ont.

Reference

1. Zed PJ, Abu-Laban RB, Chan WWY, et al. Efficacy, safety and patient satisfaction of propofol for procedural sedation and analgesia in the emergency department: a prospective study. CJEM 2007; 9:421-7.

[The authors respond]

To the editor: We thank Dr. Donaghy for his letter regarding our paper.1 It is clear that propofol has very effective amnestic properties, as demonstrated by the lack of procedural recall in 93.8% of patients in our study. Of the 113 patients in our study, fentanyl, the use of which was left to the discretion of the emergency physician, was administered in 19 (16.8%). These 19 patients had a mean age of 40.3 (SD 15.4) years and 73.7% were male. The procedures included 12 orthopedic manipulations, 3 abscess incision and drainages, 2 chest tube insertions, 1 foreign body removal and 1 incarcerated hernia reduction. Recall was absent in 17 patients (89.4%).

Overall, recall was reported in 7 patients (6.2%); 3 reported a pain score of 0 on a 10-point visual analog scale, and the remaining 4 patients reported pain scores of 2, 4, 4 and 5, respectively. Among the 4 patients that reported recall and pain, 2 (50%) (both shoulder dislocations) were given 100 mcg of fentanyl prior to the administration of propofol.

Dr. Donaghy raises intriguing questions regarding the appropriate use of analgesics in the setting of procedural sedation and analgesia (PSA). The current literature on this aspect of propofol suggests further study is required.2 Our study does little to clarify the situation, since only 4 patients (3.5%) reported recall and pain, and one-half of them received fentanyl, underscoring the difficulty in predicting the analgesic requirements in this patient population. A recent study published in abstract form by Miner and colleagues3 evaluated the role of alfentanil with or without propofol in patients undergoing PSA and found no difference in the propofol dose, time of procedure, changes from baseline end-tidal CO₂ or hypoxia. However, there were more supportive airway measures required in the patients who received alfentanil (34.1% alfentanil/propofol v. 12.8% propofol alone, p = 0.02). Clearly this area requires further study, not only to determine which opioid analgesic is the optimal agent, but also whether routine analgesia is necessary at all in the setting of PSA performed with propofol.

Peter J. Zed, PharmD
Capital Health and Dalhousie University
Halifax, NS

Riyad B. Abu-Laban, MD, MHSc
Vancouver General Hospital
and University of British Columbia
Vancouver, BC

David W. Harrison, MD
Vancouver General Hospital
and University of British Columbia
Vancouver, BC

References

1. Zed PJ, Abu-Laban RB, Chan WWY, et al. Efficacy, safety and patient satisfaction of propofol for procedural sedation and analgesia in the emergency department: a prospective study. CJEM 2007;9:421-7.
2. Miner JR, Krauss B. Procedural sedation and analgesia research: state of the art. Acad Emerg Med 2007;14:170-8.
3. Miner JR, Stephens D, Plummer D, et al. Randomized clinical trial of procedural sedation using propofol with and without the ultra-short acting narcotic alfentanil [abstract]. Acad Emerg Med 2007;14:S58.