Ketamine HCl

 Action 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.

 Indications Diagnostic and surgical procedures that do not require skeletal muscle relaxation; induction of anesthesia; supplementation of low-potency agents, such as nitrous oxide.

 Contraindications Schizophrenia; acute psychoses; patients in whom significant BP elevation would be serious hazard.

 Route/Dosage

ADULTS & CHILDREN: INDUCTION OF ANESTHESIA: Initial: IV 1–4.5 mg/kg via slow infusion (over 60 sec); usual dose for 5–10 min anesthesia: 2 mg/kg. IM Initial: 6.5–13 mg/kg. Maintenance: IV/IM One-half to full induction dose, repeated as needed. Alternatively IV 0.1–0.5 mg/min infusion, augmented with diazepam IV 2–5 mg.

 Interactions

Halothane: Decreased cardiac output, BP and pulse. Tubocurarine and other nondepolarizing muscle relaxants: Increased neuromuscular effects, resulting in prolonged respiratory depression. INCOMPATIBILITIES: Ketamine is physically incompatible with diazepam and barbiturates.

 Lab Test Interferences None well documented.

 Adverse Reactions

CV: Hypertension; tachycardia; hypotension; bradycardia; arrhythmia. CNS: Increased ICP. Emergence reaction: Vivid imagery; hallucinations; delirium; confusion; excitement; irrational behavior. DERM: Transient erythema; morbilliform rash. EENT: Diplopia; nystagmus; increased intraocular pressure. GI: Anorexia; nausea; vomiting; hypersalivation. RESP: Respiratory stimulation; severe respiratory depression; apnea after rapid injection; laryngospasm; other airway obstruction.

 Precautions

Pregnancy: Pregnancy category undetermined. Lactation: Undetermined. Hypertension or cardiac decompensation: In patients with these conditions, monitor function continuously during procedure.

 Administration/Storage

• Premedicate patient with anticholinergic agent before giving anesthetic to prevent salivation.
• Administer slowly over 60 sec to prevent respiratory depression, unless otherwise indicated.

 Assessment/Interventions

• Obtain patient history, including drug history and any known allergies. Note history of psychiatric disorders (schizophrenia or acute psychoses).
• Assess vital signs, especially BP, before administration.
• Place patient in quiet room with minimal stimulation to prevent recovery symptoms.
• Observe patient for signs of delirium and hallucinations during recovery period.
• Check patient's airway regularly to prevent aspiration caused by hypersalivation.
• If respiratory, neurologic or cardiovascular changes (hypertension, tachycardia, hypotension, bradycardia, arrhythmia) occur, notify physician. Be prepared to support patient physically.

 Patient/Family Education

• Advise patient that neurologic effects may persist for 24 hr after anesthesia. Advise patient to use caution during this period while driving or performing other tasks requiring mental alertness.