What is the comparison between oral pentobarbital (Pentobarbital) and intramuscular (IM) ketamine (Ketamine) for procedural sedation?

From the Guidelines

For procedural sedation, intramuscular (IM) ketamine is generally preferred over oral pentobarbital due to its more predictable onset, better safety profile, and ability to provide both sedation and analgesia.

Key Considerations

• The onset of action for IM ketamine is within 3-5 minutes, whereas oral pentobarbital has a less predictable onset of 30-60 minutes 1.
• The duration of action for IM ketamine is approximately 30-40 minutes, compared to 60-240 minutes for oral pentobarbital 1.
• Ketamine maintains airway reflexes and respiratory drive while providing dissociative anesthesia, making it safer for brief painful procedures 1.
• However, ketamine may cause emergence reactions, increased secretions, and nystagmus, which can be mitigated with pretreatment using atropine (0.01-0.02 mg/kg) and midazolam (0.05-0.1 mg/kg) 1.

Administration and Monitoring

• IM ketamine is typically administered at 4-5 mg/kg, with a maximum dose of 100 mg 1.
• Oral pentobarbital is typically dosed at 2-6 mg/kg orally with a maximum of 100 mg 1.
• Monitoring vital signs, oxygen saturation, and having resuscitation equipment available is essential with either medication 1.

Evidence-Based Recommendations

• The choice between these agents should consider the specific procedure, patient characteristics, and available monitoring capabilities 1.
• Studies have shown that ketamine is effective and safe for procedural sedation in pediatric patients, with a low rate of significant adverse events 1.
• The use of ketamine has been associated with a faster onset of action and a shorter recovery time compared to oral pentobarbital 1.

From the FDA Drug Label

CLINICAL PHARMACOLOGY Barbiturates are capable of producing all levels of CNS mood alteration from excitation to mild sedation, to hypnosis, and deep coma.

1 INDICATIONS AND USAGE Ketamine hydrochloride injection is indicated: as the sole anesthetic agent for diagnostic and surgical procedures that do not require skeletal muscle relaxation.

The FDA drug label does not directly compare oral pentobarbital and IM ketamine for procedural sedation.

• Key points for ketamine include:
  • Used as the sole anesthetic agent for diagnostic and surgical procedures
  • Administered by or under the direction of physicians experienced in the administration of general anesthetics
• Key points for pentobarbital include:
  • Capable of producing all levels of CNS mood alteration from excitation to mild sedation, to hypnosis, and deep coma
  • Used for treating insomnia, but of limited value beyond short-term use 2 3

From the Research

Comparison of Oral Pentobarbital and IM Ketamine for Procedural Sedation

• The provided studies do not directly compare oral pentobarbital and IM ketamine for procedural sedation.
• However, the studies compare different sedation regimens, including ketamine and propofol, which can provide some insights into the effectiveness and safety of ketamine for procedural sedation 4, 5, 6, 7, 8.
• A study comparing propofol and midazolam/ketamine regimens found that propofol expedites patient management and saves time in the emergency department 4.
• Another study found that a ketamine/propofol mixture (ketofol) has less respiratory adverse effects than propofol alone in ED procedural sedation 5.
• A review of intravenous vs intramuscular ketamine for pediatric procedural sedation found that both modes of administration are broadly similar in terms of safety and efficacy, but intravenous administration may be preferred 6.
• A prospective cohort study on intravenous ketamine for adult procedural sedation in the emergency department found that ketamine is an effective agent with a significant incidence of recovery agitation 7.
• A randomized comparative trial comparing ketamine + midazolam to propofol for procedural sedation for lumbar puncture in pediatric oncology found that the ketamine-midazolam combination is safer and more effective, while propofol is faster in onset and recovery 8.

Key Findings

• Ketamine is an effective agent for procedural sedation, but its comparison to oral pentobarbital is not available in the provided studies.
• The choice of sedation regimen depends on various factors, including the procedure, patient population, and setting.
• Further studies are needed to directly compare oral pentobarbital and IM ketamine for procedural sedation.