What is the recommended ketamine dose for procedural sedation in a patient weighing 53 kg?

Ketamine Dose for Procedural Sedation in a 53 kg Patient

For procedural sedation in this 53 kg patient, administer 1.5-2 mg/kg IV ketamine (80-106 mg total dose), which provides optimal sedation with minimal need for supplemental dosing. 1

Recommended Dosing Protocol

Intravenous Administration (Preferred Route)

• Initial dose: 1.5-2 mg/kg IV (80-106 mg for 53 kg patient) 2, 1
• This dose is significantly more effective than lower doses, with only 5.5% of patients requiring additional doses compared to 54% when using 1.0 mg/kg 1
• Onset of action: 30-96 seconds 1
• Duration: 15-30 minutes of sedation effect 1
• Average total recovery time: approximately 84 minutes 1

Alternative Route if IV Access Unavailable

• Intramuscular: 4 mg/kg IM (212 mg for 53 kg patient) 1
• Onset: 3-4 minutes 1
• May repeat with 2-4 mg/kg after 5-10 minutes if inadequate sedation 1

Pre-Medication Considerations

Consider co-administration of midazolam 0.05-0.1 mg/kg IV (2.65-5.3 mg for 53 kg) to reduce emergence reactions, particularly beneficial in adults, reducing recovery agitation from 35.7% to 5.7% 1. However, this combination may prolong recovery time slightly 1.

Critical Monitoring Requirements

• Continuous pulse oximetry, heart rate, blood pressure monitoring throughout procedure 1
• Capnography when available 1
• Maintain oxygen saturation >93% on room air 1
• Document vital signs at minimum every 5 minutes 1
• Practitioners must be able to identify and rescue patients from unintended deep sedation or general anesthesia 2
• Maintain vascular access throughout procedure until patient no longer at risk for cardiorespiratory depression 2

Absolute Contraindications

Avoid ketamine in this patient if any of the following are present:

• Uncontrolled cardiovascular disease 2, 1
• Active psychosis 2, 1
• Severe liver dysfunction 2
• Elevated intracranial or intraocular pressure 2, 1
• Pregnancy 2, 1
• Ischemic heart disease or cerebrovascular disease 1

Expected Adverse Events and Management

Common Side Effects

• Recovery agitation: 17.6% mild, 1.6% moderate-to-severe 1
  • Treat with midazolam if moderate-to-severe 1
• Emesis without aspiration: 6.7% 1
• Transient hypoxemia: 1.6-7.3% of cases 1
  • Usually responds to supplemental oxygen 1
  • Bag-valve-mask ventilation required in approximately 2% 1

Cardiovascular Effects

• Dose-dependent increase in heart rate, blood pressure, and cardiac output through sympathetic stimulation 1
• Maintains cardiovascular stability better than propofol or dexmedetomidine in unstable patients 3

Special Considerations for Hemodynamically Unstable Patients

If this patient has trauma or hemodynamic instability, ketamine 1-2 mg/kg remains appropriate as it maintains blood pressure through central NMDA blockade and preserved adrenal function 4, 3. Use lower end of dosing range (1 mg/kg) in multiply injured patients 4.

Discharge Criteria

Do not discharge until:

• Return to baseline mental status 1
• Stable vital signs 1
• Adequate airway reflexes restored 1
• Median time to discharge readiness: approximately 110 minutes 1