What is the maximum recommended dose of a ketamine (ketamine hydrochloride) drip?

Maximum Recommended Dose for Ketamine Drip

The maximum recommended dose for a ketamine drip is 0.5 mg/kg/hour for continuous infusion, with the infusion typically stopped 30 minutes before the end of a procedure when used perioperatively. 1

Dosing Guidelines for Ketamine Infusions

FDA-Approved Dosing for Anesthesia

• For maintenance of anesthesia, ketamine can be administered as a slow microdrip infusion at 0.1 to 0.5 mg/minute (6-30 mg/hour) to maintain general anesthesia in adult patients 2
• When administered as part of balanced anesthesia in combination with other agents, a reduced dose of ketamine should be used 2
• For induction of anesthesia, ketamine can be administered as an intravenous infusion at a rate of 0.5 mg/kg/min 2

Perioperative Pain Management

• For perioperative pain management, the maximum recommended continuous infusion is 0.125-0.25 mg/kg/hour 1
• The infusion should be stopped approximately 30 minutes before the end of surgery to minimize side effects 1
• For acute pain management, subanesthetic doses include infusions at 0.5-1 mg/kg/hour 1

Preparation of Ketamine Infusions

• For maintenance infusions, dilute ketamine to create a 1 mg/mL solution by adding 10 mL from a 50 mg/mL vial (or 5 mL from a 100 mg/mL vial) to 500 mL of 5% Dextrose or 0.9% Sodium Chloride 2
• When fluid restriction is required, ketamine can be added to a 250 mL infusion to provide a 2 mg/mL concentration 2
• The 100 mg/mL concentration should never be administered intravenously without proper dilution 2

Safety Considerations and Monitoring

Required Monitoring

• Continuous vital sign monitoring is essential for all patients receiving ketamine infusions 2
• Emergency airway equipment must be immediately available during ketamine administration 2
• Regular assessment of sedation levels and respiratory status is essential 1
• Maintain vascular access throughout the procedure until the patient is no longer at risk for cardiorespiratory depression 1

Adverse Effects and Precautions

• Higher doses of ketamine (>2 mg/kg IV) are associated with increased odds of adverse events including hypotension, laryngospasm, bradycardia, oxygen desaturation, and failed airway management 3
• Rapid administration may result in respiratory depression and enhanced vasopressor response 2
• For prolonged ketamine infusions, monitoring for hemodynamic stability is essential, though studies have shown that continuous infusions can be maintained safely with average heart rates of 93 bpm and blood pressures of 128/71 mmHg 4

Special Considerations

Pediatric Dosing

• In pediatric patients, lower doses of ketamine (0.5-1.0 mg/kg IV) have been shown to be effective for procedural sedation, with 88% of patients successfully sedated at initial doses of 1 mg/kg or less 5
• For pediatric procedural sedation, a combination of ketamine and midazolam has shown fewer complications compared to midazolam/meperidine regimens 6

Off-Label Uses

• For depression treatment, ketamine infusions are typically administered at 0.5 mg/kg over 40 minutes, though sessions ranging from 2 to 100 minutes have demonstrated safety and efficacy 7
• Some patients may respond to doses as low as 0.1 mg/kg, while others may require up to 0.75 mg/kg 7

Contraindications

• Ketamine should not be used in patients with uncontrolled cardiovascular disease, pregnancy, active psychosis, severe liver dysfunction, or high intracranial/ocular pressure 1
• Due to potential for salivation during ketamine administration, an antisialagogue should be administered prior to induction of anesthesia 2

Remember that ketamine administration should be performed by or under the direction of physicians experienced in general anesthetics, airway management, and ventilation to ensure patient safety 2.