Ketamine for Procedural Sedation – Efficacy and Cost Effectiveness

October 2008

Ketamine for Procedural Sedation – Efficacy and Cost Effectiveness

Search Strategy: 2 search strategies were used. First, OVID was searched with keywords: ketamine and sedation. This yielded 506 results. Limiting articles to those containing adult and emergency led to 11 articles from which 3 were chosen. Additionally, a lengthy cost-effectiveness analysis was obtained after attending a recent BEEM conference.

It is a typical busy weekend in the Emergency Department. You look at HMED for the next patient to be seen and see the chief complaint: spider bite. After a quick history and examination you realize this patient will need an incision and drainage of a large buttock abscess.

As you gather your supplies, you tell the nurse the patient will need sedation. The RN asks what medications you want for sedation. Before you are able to give your answer, the pediatric fellow who is rotating through the department asks you about using ketamine in your sedation. We use it across the street all time, he says. You answer “Hmmm. Let me look that up!”


PICO Question

Population: Adult patients requiring sedation

Intervention: Ketamine sedation in emergency setting

Comparison: Non-ketamine in emergency setting

Outcome: Ketamine efficacy in procedural sedation vs. other agents, side effects, cost-effectiveness.


Years

First years: A Combination of Midazolam and Ketamine for Procedural Sedation and Analgesia in Adult Emergency Department Patients, Acad Emerg Med 2000; 7: 228-235. (http://pmid.us/10730829)

Second years: Intravenous ketamine for adult procedural sedation in the emergency department: a prospective cohort study. Emerg Med J 2008; 25: 498-501. (http://pmid.us/18660398)

Third years: Subdissociative-dose Ketamine versus Fentanyl for Analgesia during Propofol Procedural Sedation: A Randomized Clinical Trial, Acad Emerg Med 2008; epub ahead of printing. (http://pmid.us/18754820)

Fourth years: Short-acting agents for procedural sedation and analgesia in Canadian emergency departments: A review of clinical outcomes and economic evaluation, Canadian Agency for Drugs and Technologies in Health 2008 (www.cadth.ca) pp 31 – 47, 50-51.


Articles

Article 1: A Combination of Midazolam and Ketamine for Procedural Sedation and Analgesia in Adult Emergency Department Patients, Acad EM 2000; 7:228-235
ANSWER KEY

Article 2: Intravenous ketamine for adult procedural sedation in the emergency department: a prospective cohort study, Emerg Med J 2008; 25: 498-501
ANSWER KEY

Article 3: Subdissociative-dose Ketamine versus Fentanyl for Analgesia during Propofol Procedural Sedation: A Randomized Clinical Trial, Acad Emerg Med 2008;15:1-10
ANSWER KEY

Article 4: Short-Acting Agents for Procedural Sedation and Analgesia in Canadian Emergency Departments: A Review of Clinical Outcomes and Economic Evaluation, Canadian Agency for Drugs and Technologies in Health 2008
ANSWER KEY


Bottom Line

Midazolam (0.07mg/kg) followed 2-minutes later by ketamine (2mg/kg) is a safe (~3% mild emergence reactions), effective (all patients would choose again) procedural sedation combination for abscess drainage or orthopedic reduction. On the other hand, ketamine (0.5mg/kg IV) alone almost always provides sufficient procedural sedation for orthopedic procedures, but over 20% will experience an adverse reaction (most commonly an emergence reaction) necessitating midazolam therapy. One well-designed, single-center, multiply blinded RCT suggests that ketamine (0.3mg/kg) is safer than fentanyl (1.5mg/µg/kg) when used as an adjunct to titrated propofol for ED procedural sedation of orthopedic injuries in young healthy adults. Quantitatively, the ketamine NNT = 2.5 to avoid one desaturation < 92% while the fentanyl NNH = 2.8 to cause one desaturation < 80%. The lack of any observed emergence phenomena likely resulted from the protective effect of propofol and the low dose of ketamine in a very select patient population. A Canadian analysis suggests that at a savings of $336/case, propofol dominates the cost-minimization analysis of ED PSA with short-acting agents. Ketamine and ketofol suffer from insufficient cost-effectiveness data upon which to base assumptions, but still yield robust savings of $244/case. A procedural sedation check-list should be used to incorporate the myriad ketamine exclusionary criteria if this agent is to be used in the ED.