From the Guidelines
Ketamine hydrochloride is recommended for conscious sedation at an initial intravenous dose of 1 mg/kg, as supported by the study by Acworth et al 1, which demonstrated superior sedation onset and physician satisfaction compared to other regimens. For conscious sedation, ketamine hydrochloride can be administered at an initial intravenous dose of 0.5-1 mg/kg given slowly over 1-2 minutes, with additional doses of 0.25-0.5 mg/kg as needed to maintain sedation. Alternatively, intramuscular administration can be used at 2-4 mg/kg, as seen in the study by Green et al 1, which reported a low rate of significant adverse events without serious sequelae. Onset of action is rapid, occurring within 30 seconds for IV administration and 3-4 minutes for IM. When administering ketamine, patients should be monitored continuously for vital signs, oxygen saturation, and level of sedation, as emphasized in the study by Dachs and Innes 1, which highlighted the importance of close monitoring during procedural sedation. Supplemental oxygen should be available, and resuscitation equipment should be readily accessible. Ketamine works as a dissociative anesthetic by antagonizing NMDA receptors in the brain, producing a cataleptic state while maintaining respiratory drive and protective airway reflexes. It's particularly useful in procedures requiring brief sedation and analgesia, especially in pediatric patients or those with hemodynamic instability, as it tends to preserve or even increase blood pressure and heart rate, as noted in the study by Petrack et al 1. Common side effects include emergence reactions (hallucinations, vivid dreams), which can be reduced by administering benzodiazepines like midazolam (0.03-0.05 mg/kg IV) before or during ketamine administration. Key considerations for ketamine administration include:
- Monitoring for adverse events, such as respiratory depression and emesis
- Using supplemental oxygen and having resuscitation equipment available
- Administering benzodiazepines to reduce emergence reactions
- Selecting appropriate patients, such as those with hemodynamic instability or requiring brief sedation and analgesia.
From the Research
Ketamine Conscious Sedation Dosing
- The recommended dosing for ketamine (ketamine hydrochloride) for conscious sedation varies depending on the patient population and the specific procedure being performed 2, 3, 4, 5, 6.
- For pediatric patients, a dose of 1.5 mg/kg intravenously has been shown to be effective for procedural sedation, with fewer doses required and a lower overall mg/kg dosage compared to a dose of 1.0 mg/kg 2.
- For adult patients, a dose of 0.5-1.0 mg/kg intravenously has been used for procedural sedation in the emergency department, with adequate sedation obtained in 98.9% of patients and successful completion of the procedure achieved in 98.9% of patients 4.
- In difficult to sedate patients undergoing advanced endoscopic procedures, a dose of 20 mg intravenously every 5 minutes has been shown to be effective in achieving adequate sedation 5.
- The addition of ketamine to midazolam has been shown to increase the effectiveness of conscious sedation, with improved quality and depth of sedation and shorter recovery times 5, 6.
- The specific dosing regimen used should be tailored to the individual patient and the specific procedure being performed, with careful monitoring of the patient's vital signs and level of sedation 2, 3, 4, 5, 6.
Key Considerations
- The dose of ketamine used for conscious sedation should be titrated to achieve the desired level of sedation, with careful monitoring of the patient's vital signs and level of sedation 2, 3, 4, 5, 6.
- The use of ketamine for conscious sedation should be carefully considered in patients with certain medical conditions, such as hypertension, cardiovascular disease, and respiratory disease 2, 3, 4, 5, 6.
- The potential for adverse events, such as clonic movements, hypersalivation, laryngospasm, recovery agitation, and vomiting, should be carefully monitored and managed 2, 3, 4, 5, 6.