Ketamine disadvantages

The most serious disadvantage to the use of ketamine is its propensity to evoke excitatory and hallucinatory phenomena as the patient emerges from anesthesia. Patients in the recovery period may be agitated, scream and cry, hallucinate, or experience vivid dreams. These episodes may be controlled to some extent by maintaining a quiet reassuring atmosphere in which the patient can awaken or if necessary by administering tran-quilizing doses of diazepam. 

Although the use of ketamine for anesthesia induction when seizure duration is insufficient has also been recommended, recent studies did not find this agent to be helpful (100, 101, 102 and 103). Disadvantages of ketamine include the following ... 

Disadvantages. Ketamine produces no muscular relaxation. It increases intracranial and intraocular pressure. Hallucinations can occur during recovery (the emergence reaction), but they are minimised if ketamine is used solely as an induction agent and followed by a conventional inhalational anaesthetic. Their incidence is reduced by administration of a benzodiazepine both as a premedication and after the procedure. 

Lear has reviewed three chemically unrelated series of compounds used for intravenous anesthesia, that is, derivatives of cyclohexyl amines such as ketamine (XXXIII), phenoxyacetamides such as propanidid, and Y-hydroxybutyric acid. Comparative pharmacology and advantages and disadvantages are listed. 

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