Brand Name
Ketalar
Broad Class
IV anesthetic
Pharmacological class
NMDA antagonist
Chemical Class
Phencyclidine derivative
MOA (Primary)
Enters NMDA channel, binds to phencyclidine site and (noncompetetively d/t allosteric binding) antagonizes receptor by preventing glutamate to bind and influx Na+ and Ca2+, thus, depressing excitatory neurotransmission
MOA secondary
- Opioid: Mu and Kappa agonism (analgesic effects)
- MOA pathways (inhibits transfer enzymes for NE and serotonin reuptake)
- voltage gated calcium channel inhibition (decreased neurotransmitter release)
- Muscarinic effects (salivation)
- Cholinergic receptors
- Inhibits Na+ channels (local anesthetic action)
Indications
- Induction
-Sedation - CV collapse
- Sedation for mentally challenged
- “Bad” epidural or spinal
- Trauma inductions
- Analgesia
- opioid abuse patients
- Acute and chronic pain
- depression
- ERAS protocols
Volume of distribution
High Vd due to lipophilicity and low protein binding
Cardiac side effects
Increased HR, CO , and CI(due to catecholamine stimulation otherwise known to depress contractility)
Vascular effects
Increased BP, PAP, CVP, MAP, SVR
Respiratory effects
Maintains airway reflexes
Bronchodilation
minimal depression
Sialagogue (pretreat with glyco)
- Due to muscarinic effects
CNS effects
Potent Cerebral vasodilator
Increased CBF
Increased ICP
Increased CMRO2
Decreased sz threshold?
Emergence Delerium (pretreat with versed)
Nystagmus
potential increase in IOP
Precipitation?
Evidence of precipitation with alkaline barbiturates like thiopental
Histamine release?
No
Absolute Contraindications
Any condition the increased HR or BP would be detrimental
- Aortic dissection
- CAD (unable to tolerate increased HR)
- Sepsis (catecholamine depletion)
- Uncontrolled HTN
Relative Contraindications (precautions)
- Open globe injury (increased IOP)
- Catecholamine Depletion (sepsis, shock state, critical illness)
- Pulmonary HTN
- Cardiovascular disease
- Intracranial pathology (leisions, trauma, increased ICP)
- Severe Right Heart dysfunction
Induction dosing
2-4 mg/kg IV
(1-2mg/kg previously)
IM dosing
4-6 mg/kg
Intermittent Bolus for maintenance dosing
0.5 mg/kg
Continuous infusion dosing
0.5-2 mg/kg/hr
Analgesic bolus dosing
0.1 - 0.3 mg/kg
Analgesic infusion dosing (subanesthetic)
0.1 - 0.3 mg/kg/hr
Bronchospastic dosing
0.2 - 1 mg/kg
Onset IV
30 seconds
