Trade Names:Ketalar- Injection, solution 10 mg/mL- Injection, solution 50 mg/mL- Injection, solution 100 mg/mL
Trade Names:Ketamine- Injection, solution 10 mg/mL- Injection, solution 50 mg/mL- Injection, solution 100 mg/mL
Produces rapid-acting anesthetic state with profound analgesia, normal pharyngeal-laryngeal reflexes, normal or slightly enhanced skeletal muscle tone, cardiovascular and respiratory stimulation, and, occasionally, transient and minimal respiratory depression.
Ketamine is rapidly absorbed. Mean C max is 0.75 mcg/mL. T max is 1 h.
Distribution half-life is approximately 10 to 15 min.
Undergoes N-dealkylation, hydroxylation of cyclohexone ring, conjugation with glucuronic acid, and dehydration of the hydroxylated metabolites to form the cyclohexene derivative. The metabolite is about one-third as active as ketamine.
The beta phase half-life of ketamine is 2.5 h. Approximately 91% is excreted in urine and 3% in feces.
Onset is 30 sec (IV) and 3 to 4 min (IM).
Duration is 5 to 10 min (IV) and 12 to 25 min (IM).
Diagnostic and surgical procedures that do not require skeletal muscle relaxation; induction of anesthesia; supplementation of low-potency agents, such as nitrous oxide.
Prevention of anesthesia-induced shivering.
Patients in whom significant BP elevation would be a serious hazard; hypersensitivity to the drug.
IV Initial: 1 to 4.5 mg/kg via slow infusion (over 60 sec); usual dose for 5- to 10-min anesthesia: 2 mg/kg. Alternatively, 1 to 2 mg/kg at a rate of 0.5 mg/kg/min, augmented with diazepam IV 2 to 5 mg. Maintenance: One-half to full induction dose, repeated as needed. Alternatively, adults induced with ketamine augmented with IV diazepam may receive 0.1 to 0.5 mg/min by slow microdrip infusion, augmented with diazepam 2 to 5 mg IV as needed. IM Initial: 6.5 to 13 mg/kg. Maintenance: One-half to full induction dose, repeated as needed.
Store vials at controlled room temperature (68° to 77°F). Protect from light.
Decreased cardiac output, BP, and pulse.Tubocurarine and other nondepolarizing muscle relaxants
Increased neuromuscular effects, resulting in prolonged respiratory depression.
None well documented.
Arrhythmia, bradycardia, elevated blood pressure and heart rate, hypotension.
Enhanced skeletal muscle tone manifested by tonic and clonic movement.Emergence reaction
Confusion, delirium, excitement, hallucinations, irrational behavior, pleasant dream-like state, vivid imagery.
Morbilliform rash, transient erythema.
Diplopia, increased intraocular pressure, nystagmus.
Anorexia, nausea, vomiting.
Local pain and exanthema at injection site.
Apnea after rapid injection, laryngospasm, other airway obstruction, respiratory stimulation, severe respiratory depression.
Emergence reactions occur in approximately 12% of patients. The incidence is least frequent in elderly (older than 65 yr of age) patients and also less frequent with IM use.Psychological manifestations
Severity varies between pleasant dream-like states, vivid imagery, hallucinations, and emergence delirium, sometimes accompanied by confusion, excitement, and irrational behavior. The duration is ordinarily a few hours; however, recurrences have been seen up to 24 h postoperatively. No residual psychological effects are known. The incidence may be reduced by using lower dosages with IV diazepam. These reactions may be reduced if verbal, tactile, and visual patient stimulation is minimized during recovery. This does not preclude monitoring vital signs.Management
To terminate a severe emergence reaction, a small hypnotic dose of a short-acting or ultra short-acting barbiturate may be required. When used on an outpatient basis, do not release patient until recovery from anesthesia is complete. Patients should be accompanied by an adult.
Continually monitor cardiac function during procedures in patients with hypertension or cardiac decompensation aseptically.
Category B .
Safety and efficacy in children younger than 16 yr of age have not been established.
Use with caution, usually starting at the low end of the dosing range.
Use with caution in chronic alcoholic and acutely alcohol-intoxicated patients.
Cerebrospinal fluid pressure increase has been reported following administration.
In patients with these conditions, monitor function continuously during procedure.
May occur with overdosage or too rapid a rate of administration.
Do not use in surgery or diagnostic procedures of the pharynx, larynx, or bronchial tree. Do not administer ketamine alone because pharyngeal and laryngeal reflexes are usually active. Muscle relaxants, with proper attention to respiration, may be required.
In surgical procedures involving visceral pain pathways, supplement with an agent that obtunds visceral pain.
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